Imad Nadra - Academia.edu (original) (raw)

Papers by Imad Nadra

Research paper thumbnail of 4 Renal function-based contrast dosing to define ‘prognostic’ contrast limits in patients undergoing coronary angioplasty

Shortlisted moderated abstracts presented at YIA research abstract day, 30 November 2017, 2018

Background Renal function-based contrast dosing minimises renal injury following percutaneous cor... more Background Renal function-based contrast dosing minimises renal injury following percutaneous coronary intervention (PCI). The ratio (R) of contrast volume:glomerular filtration rate (GFR) has been studied but its prognostic relevance is unknown. Aim To establish the relationship between R and mortality; and define a ‘prognostic’ threshold (RT ) for contrast in PCI for stable disease, non ST-elevation ACS (NSTEACS) and ST-elevation ACS (STEACS). Method We evaluated 44 082 non-dialysis patients between 2008–2014. GFR was calculated using CG, CKD-EPI and MDRD equations. R was determined for each patient and its relationship with mortality was modelled mathematically and analysed using Cox regression and adjusted ROC curve analyses. Results Multivariable analyses identified R as an independent predictor of 3 year mortality (HR=1.03, 95% CI: 1.02 to 1.04, p<0.001). There was an exponential relationship between R and mortality; for every unit increase in R, 3 year mortality increased by 13%–14% regardless of PCI indication. Adjusted analyses indicated RT was consistently higher in stable disease (RT =7.7–8.3) compared to NSTEACS (RT =5.3–5.7) and STEACS (RT =5.3–5.7). Conclusion This study advocates a RT =7.7–8.3 for stable disease and RT =5.3–5.7 for NSTEACS/STEACS. This is greater than previously reported but implies greater contrast volumes may ultimately be tolerated in the contemporary PCI era.Abstract 4 Figure 1 (A) Cox regression analyses (3-year mortality) and (B) Adjusted ROC curve analysis (1,2 and 3-year mortality)

Research paper thumbnail of TCT-471 The prognostic implications of a single higher contrast volume procedure vs. separate lower contrast volume staged procedures for percutaneous coronary intervention: a decision-analytical model to define the threshold for contrast:glomerular filtration ratio in determining the optimum str...

Journal of the American College of Cardiology, 2017

Research paper thumbnail of TCT-444 The prognostic significance of complete revascularization across all indications for percutaneous coronary intervention: an analysis of 28,632 patients with multivessel disease from the British Columbia Cardiac Registry

Journal of the American College of Cardiology, 2017

Research paper thumbnail of Coronary Angiography and Revascularization Following Coronary Artery Bypass Grafting in British Columbia: Incidence, Predictors and Longer-term Outcomes

The Canadian journal of cardiology, 2018

Coronary artery bypass grafting (CABG) is established treatment for subsets of coronary artery di... more Coronary artery bypass grafting (CABG) is established treatment for subsets of coronary artery disease (CAD). Observational data have characterised significant progression of native coronary as well as graft vessel disease during longer-term follow-up, potentially reducing the benefit of CABG. We sought to assess longer-term outcomes following CABG by determining rates of repeat coronary angiography, revascularization procedures, and survival. Data for all patients undergoing isolated CABG in British Columbia between 2001 and 2009 inclusive, and with follow-up until the end of 2013, were retrieved from the British Columbia Cardiac Registry. Cox proportional hazard regression and competing risk regression were performed for survival and subsequent cardiac procedures (coronary angiography, percutaneous coronary intervention [PCI] or repeat CABG). Data were available from 17,316 patients with a mean age at index CABG of 65.7 ± 9.8 years. At a median follow-up of 8.5 (range 4.0 to 12.9)...

Research paper thumbnail of The prognostic impact of revascularization strategy in acute myocardial infarction and cardiogenic shock: Insights from the British Columbia Cardiac Registry

Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions, Jan 26, 2018

In patients with acute myocardial infarction (AMI) and cardiogenic shock (CS), percutaneous coron... more In patients with acute myocardial infarction (AMI) and cardiogenic shock (CS), percutaneous coronary intervention (PCI) of the culprit vessel is associated with improved outcomes. A large majority of these patients have multivessel disease (MVD). Whether or not PCI of non-culprit disease in the acute setting improves outcomes continues to be debated. We evaluated the prognostic impact of revascularization strategy for patients presenting with AMI and CS. We compared culprit vessel intervention (CVI) versus multivessel intervention in 649 patients with AMI, CS, and MVD enrolled in the British Columbia Cardiac Registry. We evaluated mortality at 30 days and 1 year. CVI was associated with lower mortality at 30 days (23.7% vs. 34.5%, P = 0.004) and 1 year (32.6% vs. 44.3%, P = 0.003). CVI was an independent predictor for survival at 30 days (HR = 0.63, 95% CI: 0.45-0.88, P = 0.009) and 1 year (HR = 0.72, 95% CI: 0.54-0.96, P = 0.027). These findings were confirmed in propensity-matched...

Research paper thumbnail of Renal Function-Based Contrast Dosing to Define “Prognostic” Contrast Dose Limits for Percutaneous Coronary Intervention – the Prognostic Implication of the Contrast Volume: Glomerular Filtration Ratio in 44,082 Patients from the British Columbia Cardiac Registry

Journal of the American College of Cardiology, 2017

Background: Renal function-based contrast dosing to limit renal injury following percutaneous cor... more Background: Renal function-based contrast dosing to limit renal injury following percutaneous coronary intervention (PCI) has been studied but its prognostic relevance is unknown. We evaluated the contrast volume: glomerular filtration rate (GFR) ratio (R) to define “prognostic” limits for

Research paper thumbnail of Variation in practice and concordance with guideline criteria for length of stay after elective percutaneous coronary intervention

Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions, Jan 31, 2017

Considerable variability remains as regards the appropriate and safe length of stay after electiv... more Considerable variability remains as regards the appropriate and safe length of stay after elective PCI. We performed a survey of interventional cardiologists to identify current views on appropriate and safe length of stay after PCI. We created an online survey using the commercially available SurveyMonkey application. This was sent to interventional cardiologists in the US, Canada and the UK with the assistance of the national interventional cardiology societies (SCAI, CAIC/CCS, BCIS/BCS) as well as being made available on the theheart.org website. 505 interventional cardiologists responded, of which 237 were practicing in the US. Of those from the US, 52% were not aware of any guidelines for length of stay and 48% reported that their unit did not have a standard practice for length of stay. Same-day discharge after PCI was practiced as routine by 14% of cardiologists in the US versus 32% of cardiologists from Canada (P = 0.003) and 57% (P < 0.0001) from the UK. Amongst responde...

Research paper thumbnail of Culprit Vessel Versus Multivessel Versus In-Hospital Staged Intervention for Patients With ST-Segment Elevation Myocardial Infarction and Multivessel Disease: Stratified Analyses in High-Risk Patient Groups and Anatomic Subsets of Nonculprit Disease

JACC. Cardiovascular interventions, Jan 9, 2017

This study evaluated revascularization strategies for patients with ST-segment elevation myocardi... more This study evaluated revascularization strategies for patients with ST-segment elevation myocardial infarction (STEMI) and multivessel disease. In patients with STEMI and multivessel disease, it is unclear whether multivessel intervention (MVI), culprit vessel intervention (CVI) only (CVI-O) or CVI with staged revascularization (CVI-S) is associated with improved outcomes. Whether MVI at primary percutaneous coronary intervention may benefit specific patient groups is unclear. We compared revascularization strategies (MVI, CVI-O, and CVI-S) in 6,503 patients with STEMI and multivessel disease enrolled in the British Columbia Cardiac Registry (2008 to 2014). We evaluated all-cause mortality and repeat revascularization at 2 years. Compared with MVI, CVI-O (hazard ratio [HR]: 0.78; 95% confidence interval [CI]: 0.64 to 0.97; p = 0.023) and CVI-S (HR: 0.55; 95% CI: 0.36 to 0.82; p = 0.004) were associated with lower mortality. Comparing CVI-O with CVI-S, CVI-S was associated with lower...

Research paper thumbnail of The Prognostic Significance of Renal Disease According to Indication for Percutaneous Coronary Intervention: An Analysis of 45,288 Patients from the British Columbia Cardiac Registry

Journal of the American College of Cardiology, 2016

Research paper thumbnail of Radial artery pseudoaneurysms after transradial cardiac catheterisation

VASA. Zeitschrift für Gefässkrankheiten, 2016

Although uncommon, radial artery access site complications are likely to become more frequent wit... more Although uncommon, radial artery access site complications are likely to become more frequent with the increased adoption of transradial cardiac catheterisation. There is a lack of data regarding the incidence and clinical features of radial artery pseudoaneuryms. We aimed to describe the incidence, clinical features and management of radial artery pseudoaneurysms in a high-volume transradial cardiac catheterisation centre. We performed a search of the Vancouver Island Health Authority medical imaging database from 1st Jan 2008 to April 2012 looking for all radial and femoral artery pseudoaneuryms occurring after cardiac catheterisation. Hospital charts were reviewed to determine patient and procedural characteristics as well as management and outcome. There were a total of 14,968 coronary procedures performed over the four year search period, of which 13,216 (88%) were trans-radial. The incidence of radial artery pseudoaneurysm after cardiac catheterisation was 0.08%, and did not d...

Research paper thumbnail of Long-term outcomes following drug-eluting stents versus bare metal stents for primary percutaneous coronary intervention: A real-world analysis of 11,181 patients from the british columbia cardiac registry

Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions, Jan 4, 2016

Drug eluting stents (DES) are associated with reduced risk of restenosis when compared with bare ... more Drug eluting stents (DES) are associated with reduced risk of restenosis when compared with bare metal stents (BMS). Their use in ST-elevation myocardial infarction (STEMI) is debated, owing to concerns about stent thrombosis. There are limited real-world data comparing DES versus BMS in STEMI. We conducted an observational analysis in this setting and rigorously adjusted for treatment selection bias. We analyzed 11,181 consecutive patients with acute STEMI who received either DES or BMS during 2008-2014 in the British Columbia Cardiac Registry. We analyzed target vessel revascularization (TVR) and mortality at 2 years. Multivariable-adjusted, propensity-matched and inverse probability-treatment weighted analyses found DES to be associated with early and late survival up to 2 years but not TVR. However, when adjusting for measured and unmeasured confounders, instrumental variable (IV) analyses demonstrated that DES use was associated with reduced TVR up to 2 years (Δ = -6.7%, 95% CI...

Research paper thumbnail of Intra-Aortic Balloon Pump Counterpulsation during Primary Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction and Cardiogenic Shock: Insights from the British Columbia Cardiac Registry

PloS one, 2016

Cardiogenic shock complicating ST-elevation myocardial infarction (STEMI) is associated with sign... more Cardiogenic shock complicating ST-elevation myocardial infarction (STEMI) is associated with significant morbidity and mortality. In the primary percutaneous coronary intervention (PPCI) era, randomized trials have not shown a survival benefit with intra-aortic balloon pump (IABP) therapy. This differs to observational data which show a detrimental effect, potentially reflecting bias and confounding. Without robust and valid risk adjustment, findings from non-randomized studies may remain biased. We compared long-term mortality following IABP therapy in patients with cardiogenic shock undergoing PPCI during 2008-2013 from the British Columbia Cardiac Registry. We addressed measured and unmeasured confounding using propensity score and instrumental variable methods. A total of 12,105 patients with STEMI were treated with PPCI during the study period. Of these, 700 patients (5.8%) had cardiogenic shock. Of the patients with cardiogenic shock, 255 patients (36%) received IABP therapy. ...

Research paper thumbnail of Prognostic Significance of Polymer Coatings in Zotarolimus-Eluting Stents

The American Journal of Cardiology, 2016

Polymer coatings on drug-eluting stents (DES) serve as a vehicle for delivery of antirestenotic d... more Polymer coatings on drug-eluting stents (DES) serve as a vehicle for delivery of antirestenotic drugs. Whether they influence outcomes for contemporary DES is unknown. The evolution of polymer coatings for zotarolimus-eluting stents (ZES) provides a natural experiment that facilitates such analysis. The Resolute ZES (R-ZES) uses the same antirestenotic drug as the Endeavor ZES (E-ZES) but has a more biocompatible polymer with enhanced drug release kinetics. However, there are limited data on the real-world comparative efficacy of R-ZES and the preceding E-ZES. Thus, we analyzed 17,643 patients who received either E-ZES or R-ZES from 2008 to 2014 from the British Columbia Cardiac Registry. A total of 9,869 patients (56%) received E-ZES and 7,774 patients (44%) received R-ZES. Compared with E-ZES, R-ZES was associated with lower 2-year mortality (4.1% vs 6.4%, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001) and 2-year target vessel revascularization (TVR; 6.8% vs 10.7%, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001). R-ZES use was an independent predictor of lower mortality rate and TVR. This was confirmed in propensity-matched analyses for 2-year mortality (hazard ratio [HR] 0.59, 95% CI 0.49 to 0.71, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001) and 2-year TVR (HR 0.86, 95% CI 0.75 to 0.98, p = 0.032). Instrumental variable analyses demonstrated R-ZES to be associated with lower 2-year mortality (Δ = -2.2%, 95% CI -4.3% to -0.2%, p = 0.032) and 2-year TVR (Δ = -3.3% to 95% CI -6.1% to -0.7%, p = 0.015). Acknowledging the limitations of observational analyses, this study has shown that R-ZES was associated with lower long-term TVR and mortality. These data are reassuring for the newer R-ZES and demonstrate how polymer coatings may influence the clinical performance of DES with wider implications for future DES development and design.

Research paper thumbnail of TCT-445 The prognostic significance of repeat revascularization after percutaneous coronary intervention: an analysis of 41,180 patients from the British Columbia Cardiac Registry

Journal of the American College of Cardiology, 2015

Research paper thumbnail of Embolic protection device use and its association with procedural safety and long-term outcomes following saphenous vein graft intervention: An analysis from the British Columbia Cardiac registry

Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions, Jan 20, 2015

Embolic protection devices (EPDs) have been designed and introduced to reduce distal embolization... more Embolic protection devices (EPDs) have been designed and introduced to reduce distal embolization and peri-procedural myocardial infarction during saphenous vein graft (SVG) intervention. Current guidelines give a class I recommendation to EPD use during SVG intervention when technically feasible. However, the routine use of these devices has recently been debated. We analyzed 1,359 patients undergoing isolated SVG intervention between 2008 and 2013 in the British Columbia Cardiac Registry. We analyzed (a) post-procedural TIMI flow; and (b) target vessel revascularization (TVR) and mortality at 1 and 2 years. EPD use was an independent predictor of post-procedural TIMI 2/3 flow (OR = 2.38, 95% CI: 1.51-3.74, P < 0.001). At 1 year, EPD use was an independent predictor for lower TVR (HR = 0.35, 95% CI: 0.14-0.85, P = 0.021) and a trend towards lower mortality (HR = 0.45, 95% CI: 0.18-1.10, P = 0.082). These associations were lost at 2 years where EPD use was not predictive of morta...

Research paper thumbnail of TCT-6 The optimal timing for staged non-culprit vessel intervention following primary percutaneous coronary intervention for patients with ST-elevation myocardial infarction and multivessel disease: insights from the British Columbia Cardiac Registry using decision analytical methods

Journal of the American College of Cardiology, 2017

Patients having culprit vessel intervention at primary percutaneous coronary intervention (PCI) m... more Patients having culprit vessel intervention at primary percutaneous coronary intervention (PCI) may undergo staged PCI of non-culprit disease. Whether this is performed as an inpatient (IP) or outpatient (OP) requires balancing of the risks of PCI in the vulnerable peri-infarct period versus

Research paper thumbnail of Colocalization with CD 18 Neutrophils : Alterations in the Cytoskeleton Signaling Functions of L-Selectin in

Ligation and clustering of L-selectin by Ab ("cross-linking") or physiologic ligands results in a... more Ligation and clustering of L-selectin by Ab ("cross-linking") or physiologic ligands results in activation of diverse responses that favor enhanced microvascular sequestration and emigration of neutrophils. The earliest responses include a rise in intracellular calcium, enhanced tyrosine phosphorylation, and activation of extracellular signal-regulated kinases. Additionally, cross-linking of L-selectin induces sustained shape change and activation of ␤ 2 integrins, leading to neutrophil arrest under conditions of shear flow. In this report, we examined several possible mechanisms whereby transmembrane signals from L-selectin might contribute to an increase in the microvascular retention of neutrophils and enhanced efficiency of emigration. In human peripheral blood neutrophils, cross-linking of L-selectin induced alterations in cellular biophysical properties, including a decrease in cell deformability associated with F-actin assembly and redistribution, as well as enhanced adhesion of microspheres bound to ␤ 2 integrins. L-selectin and the ␤ 2 integrin became spatially colocalized as determined by confocal immunofluorescence microscopy and fluorescence resonance energy transfer. We conclude that intracellular signals from L-selectin may enhance the microvascular sequestration of neutrophils at sites of inflammation through a combination of cytoskeletal alterations leading to cell stiffening and an increase in adhesiveness mediated through alterations in ␤ 2 integrins.

Research paper thumbnail of Where Do We Stand with Anticoagulation in Primary Pci? A Meta-Analysis of Randomized Trials Comparing Unfractionated Heparin with Bivalirudin

Canadian Journal of Cardiology

Research paper thumbnail of Radial artery pseudoaneurysms after transradial cardiac catheterisation

VASA. Zeitschrift für Gefässkrankheiten, 2016

Although uncommon, radial artery access site complications are likely to become more frequent wit... more Although uncommon, radial artery access site complications are likely to become more frequent with the increased adoption of transradial cardiac catheterisation. There is a lack of data regarding the incidence and clinical features of radial artery pseudoaneuryms. We aimed to describe the incidence, clinical features and management of radial artery pseudoaneurysms in a high-volume transradial cardiac catheterisation centre. We performed a search of the Vancouver Island Health Authority medical imaging database from 1st Jan 2008 to April 2012 looking for all radial and femoral artery pseudoaneuryms occurring after cardiac catheterisation. Hospital charts were reviewed to determine patient and procedural characteristics as well as management and outcome. There were a total of 14,968 coronary procedures performed over the four year search period, of which 13,216 (88%) were trans-radial. The incidence of radial artery pseudoaneurysm after cardiac catheterisation was 0.08%, and did not d...

Research paper thumbnail of Long-term outcomes following drug-eluting stents versus bare metal stents for primary percutaneous coronary intervention: A real-world analysis of 11,181 patients from the british columbia cardiac registry

Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions, Jan 4, 2016

Drug eluting stents (DES) are associated with reduced risk of restenosis when compared with bare ... more Drug eluting stents (DES) are associated with reduced risk of restenosis when compared with bare metal stents (BMS). Their use in ST-elevation myocardial infarction (STEMI) is debated, owing to concerns about stent thrombosis. There are limited real-world data comparing DES versus BMS in STEMI. We conducted an observational analysis in this setting and rigorously adjusted for treatment selection bias. We analyzed 11,181 consecutive patients with acute STEMI who received either DES or BMS during 2008-2014 in the British Columbia Cardiac Registry. We analyzed target vessel revascularization (TVR) and mortality at 2 years. Multivariable-adjusted, propensity-matched and inverse probability-treatment weighted analyses found DES to be associated with early and late survival up to 2 years but not TVR. However, when adjusting for measured and unmeasured confounders, instrumental variable (IV) analyses demonstrated that DES use was associated with reduced TVR up to 2 years (Δ = -6.7%, 95% CI...

Research paper thumbnail of 4 Renal function-based contrast dosing to define ‘prognostic’ contrast limits in patients undergoing coronary angioplasty

Shortlisted moderated abstracts presented at YIA research abstract day, 30 November 2017, 2018

Background Renal function-based contrast dosing minimises renal injury following percutaneous cor... more Background Renal function-based contrast dosing minimises renal injury following percutaneous coronary intervention (PCI). The ratio (R) of contrast volume:glomerular filtration rate (GFR) has been studied but its prognostic relevance is unknown. Aim To establish the relationship between R and mortality; and define a ‘prognostic’ threshold (RT ) for contrast in PCI for stable disease, non ST-elevation ACS (NSTEACS) and ST-elevation ACS (STEACS). Method We evaluated 44 082 non-dialysis patients between 2008–2014. GFR was calculated using CG, CKD-EPI and MDRD equations. R was determined for each patient and its relationship with mortality was modelled mathematically and analysed using Cox regression and adjusted ROC curve analyses. Results Multivariable analyses identified R as an independent predictor of 3 year mortality (HR=1.03, 95% CI: 1.02 to 1.04, p<0.001). There was an exponential relationship between R and mortality; for every unit increase in R, 3 year mortality increased by 13%–14% regardless of PCI indication. Adjusted analyses indicated RT was consistently higher in stable disease (RT =7.7–8.3) compared to NSTEACS (RT =5.3–5.7) and STEACS (RT =5.3–5.7). Conclusion This study advocates a RT =7.7–8.3 for stable disease and RT =5.3–5.7 for NSTEACS/STEACS. This is greater than previously reported but implies greater contrast volumes may ultimately be tolerated in the contemporary PCI era.Abstract 4 Figure 1 (A) Cox regression analyses (3-year mortality) and (B) Adjusted ROC curve analysis (1,2 and 3-year mortality)

Research paper thumbnail of TCT-471 The prognostic implications of a single higher contrast volume procedure vs. separate lower contrast volume staged procedures for percutaneous coronary intervention: a decision-analytical model to define the threshold for contrast:glomerular filtration ratio in determining the optimum str...

Journal of the American College of Cardiology, 2017

Research paper thumbnail of TCT-444 The prognostic significance of complete revascularization across all indications for percutaneous coronary intervention: an analysis of 28,632 patients with multivessel disease from the British Columbia Cardiac Registry

Journal of the American College of Cardiology, 2017

Research paper thumbnail of Coronary Angiography and Revascularization Following Coronary Artery Bypass Grafting in British Columbia: Incidence, Predictors and Longer-term Outcomes

The Canadian journal of cardiology, 2018

Coronary artery bypass grafting (CABG) is established treatment for subsets of coronary artery di... more Coronary artery bypass grafting (CABG) is established treatment for subsets of coronary artery disease (CAD). Observational data have characterised significant progression of native coronary as well as graft vessel disease during longer-term follow-up, potentially reducing the benefit of CABG. We sought to assess longer-term outcomes following CABG by determining rates of repeat coronary angiography, revascularization procedures, and survival. Data for all patients undergoing isolated CABG in British Columbia between 2001 and 2009 inclusive, and with follow-up until the end of 2013, were retrieved from the British Columbia Cardiac Registry. Cox proportional hazard regression and competing risk regression were performed for survival and subsequent cardiac procedures (coronary angiography, percutaneous coronary intervention [PCI] or repeat CABG). Data were available from 17,316 patients with a mean age at index CABG of 65.7 ± 9.8 years. At a median follow-up of 8.5 (range 4.0 to 12.9)...

Research paper thumbnail of The prognostic impact of revascularization strategy in acute myocardial infarction and cardiogenic shock: Insights from the British Columbia Cardiac Registry

Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions, Jan 26, 2018

In patients with acute myocardial infarction (AMI) and cardiogenic shock (CS), percutaneous coron... more In patients with acute myocardial infarction (AMI) and cardiogenic shock (CS), percutaneous coronary intervention (PCI) of the culprit vessel is associated with improved outcomes. A large majority of these patients have multivessel disease (MVD). Whether or not PCI of non-culprit disease in the acute setting improves outcomes continues to be debated. We evaluated the prognostic impact of revascularization strategy for patients presenting with AMI and CS. We compared culprit vessel intervention (CVI) versus multivessel intervention in 649 patients with AMI, CS, and MVD enrolled in the British Columbia Cardiac Registry. We evaluated mortality at 30 days and 1 year. CVI was associated with lower mortality at 30 days (23.7% vs. 34.5%, P = 0.004) and 1 year (32.6% vs. 44.3%, P = 0.003). CVI was an independent predictor for survival at 30 days (HR = 0.63, 95% CI: 0.45-0.88, P = 0.009) and 1 year (HR = 0.72, 95% CI: 0.54-0.96, P = 0.027). These findings were confirmed in propensity-matched...

Research paper thumbnail of Renal Function-Based Contrast Dosing to Define “Prognostic” Contrast Dose Limits for Percutaneous Coronary Intervention – the Prognostic Implication of the Contrast Volume: Glomerular Filtration Ratio in 44,082 Patients from the British Columbia Cardiac Registry

Journal of the American College of Cardiology, 2017

Background: Renal function-based contrast dosing to limit renal injury following percutaneous cor... more Background: Renal function-based contrast dosing to limit renal injury following percutaneous coronary intervention (PCI) has been studied but its prognostic relevance is unknown. We evaluated the contrast volume: glomerular filtration rate (GFR) ratio (R) to define “prognostic” limits for

Research paper thumbnail of Variation in practice and concordance with guideline criteria for length of stay after elective percutaneous coronary intervention

Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions, Jan 31, 2017

Considerable variability remains as regards the appropriate and safe length of stay after electiv... more Considerable variability remains as regards the appropriate and safe length of stay after elective PCI. We performed a survey of interventional cardiologists to identify current views on appropriate and safe length of stay after PCI. We created an online survey using the commercially available SurveyMonkey application. This was sent to interventional cardiologists in the US, Canada and the UK with the assistance of the national interventional cardiology societies (SCAI, CAIC/CCS, BCIS/BCS) as well as being made available on the theheart.org website. 505 interventional cardiologists responded, of which 237 were practicing in the US. Of those from the US, 52% were not aware of any guidelines for length of stay and 48% reported that their unit did not have a standard practice for length of stay. Same-day discharge after PCI was practiced as routine by 14% of cardiologists in the US versus 32% of cardiologists from Canada (P = 0.003) and 57% (P < 0.0001) from the UK. Amongst responde...

Research paper thumbnail of Culprit Vessel Versus Multivessel Versus In-Hospital Staged Intervention for Patients With ST-Segment Elevation Myocardial Infarction and Multivessel Disease: Stratified Analyses in High-Risk Patient Groups and Anatomic Subsets of Nonculprit Disease

JACC. Cardiovascular interventions, Jan 9, 2017

This study evaluated revascularization strategies for patients with ST-segment elevation myocardi... more This study evaluated revascularization strategies for patients with ST-segment elevation myocardial infarction (STEMI) and multivessel disease. In patients with STEMI and multivessel disease, it is unclear whether multivessel intervention (MVI), culprit vessel intervention (CVI) only (CVI-O) or CVI with staged revascularization (CVI-S) is associated with improved outcomes. Whether MVI at primary percutaneous coronary intervention may benefit specific patient groups is unclear. We compared revascularization strategies (MVI, CVI-O, and CVI-S) in 6,503 patients with STEMI and multivessel disease enrolled in the British Columbia Cardiac Registry (2008 to 2014). We evaluated all-cause mortality and repeat revascularization at 2 years. Compared with MVI, CVI-O (hazard ratio [HR]: 0.78; 95% confidence interval [CI]: 0.64 to 0.97; p = 0.023) and CVI-S (HR: 0.55; 95% CI: 0.36 to 0.82; p = 0.004) were associated with lower mortality. Comparing CVI-O with CVI-S, CVI-S was associated with lower...

Research paper thumbnail of The Prognostic Significance of Renal Disease According to Indication for Percutaneous Coronary Intervention: An Analysis of 45,288 Patients from the British Columbia Cardiac Registry

Journal of the American College of Cardiology, 2016

Research paper thumbnail of Radial artery pseudoaneurysms after transradial cardiac catheterisation

VASA. Zeitschrift für Gefässkrankheiten, 2016

Although uncommon, radial artery access site complications are likely to become more frequent wit... more Although uncommon, radial artery access site complications are likely to become more frequent with the increased adoption of transradial cardiac catheterisation. There is a lack of data regarding the incidence and clinical features of radial artery pseudoaneuryms. We aimed to describe the incidence, clinical features and management of radial artery pseudoaneurysms in a high-volume transradial cardiac catheterisation centre. We performed a search of the Vancouver Island Health Authority medical imaging database from 1st Jan 2008 to April 2012 looking for all radial and femoral artery pseudoaneuryms occurring after cardiac catheterisation. Hospital charts were reviewed to determine patient and procedural characteristics as well as management and outcome. There were a total of 14,968 coronary procedures performed over the four year search period, of which 13,216 (88%) were trans-radial. The incidence of radial artery pseudoaneurysm after cardiac catheterisation was 0.08%, and did not d...

Research paper thumbnail of Long-term outcomes following drug-eluting stents versus bare metal stents for primary percutaneous coronary intervention: A real-world analysis of 11,181 patients from the british columbia cardiac registry

Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions, Jan 4, 2016

Drug eluting stents (DES) are associated with reduced risk of restenosis when compared with bare ... more Drug eluting stents (DES) are associated with reduced risk of restenosis when compared with bare metal stents (BMS). Their use in ST-elevation myocardial infarction (STEMI) is debated, owing to concerns about stent thrombosis. There are limited real-world data comparing DES versus BMS in STEMI. We conducted an observational analysis in this setting and rigorously adjusted for treatment selection bias. We analyzed 11,181 consecutive patients with acute STEMI who received either DES or BMS during 2008-2014 in the British Columbia Cardiac Registry. We analyzed target vessel revascularization (TVR) and mortality at 2 years. Multivariable-adjusted, propensity-matched and inverse probability-treatment weighted analyses found DES to be associated with early and late survival up to 2 years but not TVR. However, when adjusting for measured and unmeasured confounders, instrumental variable (IV) analyses demonstrated that DES use was associated with reduced TVR up to 2 years (Δ = -6.7%, 95% CI...

Research paper thumbnail of Intra-Aortic Balloon Pump Counterpulsation during Primary Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction and Cardiogenic Shock: Insights from the British Columbia Cardiac Registry

PloS one, 2016

Cardiogenic shock complicating ST-elevation myocardial infarction (STEMI) is associated with sign... more Cardiogenic shock complicating ST-elevation myocardial infarction (STEMI) is associated with significant morbidity and mortality. In the primary percutaneous coronary intervention (PPCI) era, randomized trials have not shown a survival benefit with intra-aortic balloon pump (IABP) therapy. This differs to observational data which show a detrimental effect, potentially reflecting bias and confounding. Without robust and valid risk adjustment, findings from non-randomized studies may remain biased. We compared long-term mortality following IABP therapy in patients with cardiogenic shock undergoing PPCI during 2008-2013 from the British Columbia Cardiac Registry. We addressed measured and unmeasured confounding using propensity score and instrumental variable methods. A total of 12,105 patients with STEMI were treated with PPCI during the study period. Of these, 700 patients (5.8%) had cardiogenic shock. Of the patients with cardiogenic shock, 255 patients (36%) received IABP therapy. ...

Research paper thumbnail of Prognostic Significance of Polymer Coatings in Zotarolimus-Eluting Stents

The American Journal of Cardiology, 2016

Polymer coatings on drug-eluting stents (DES) serve as a vehicle for delivery of antirestenotic d... more Polymer coatings on drug-eluting stents (DES) serve as a vehicle for delivery of antirestenotic drugs. Whether they influence outcomes for contemporary DES is unknown. The evolution of polymer coatings for zotarolimus-eluting stents (ZES) provides a natural experiment that facilitates such analysis. The Resolute ZES (R-ZES) uses the same antirestenotic drug as the Endeavor ZES (E-ZES) but has a more biocompatible polymer with enhanced drug release kinetics. However, there are limited data on the real-world comparative efficacy of R-ZES and the preceding E-ZES. Thus, we analyzed 17,643 patients who received either E-ZES or R-ZES from 2008 to 2014 from the British Columbia Cardiac Registry. A total of 9,869 patients (56%) received E-ZES and 7,774 patients (44%) received R-ZES. Compared with E-ZES, R-ZES was associated with lower 2-year mortality (4.1% vs 6.4%, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001) and 2-year target vessel revascularization (TVR; 6.8% vs 10.7%, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001). R-ZES use was an independent predictor of lower mortality rate and TVR. This was confirmed in propensity-matched analyses for 2-year mortality (hazard ratio [HR] 0.59, 95% CI 0.49 to 0.71, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001) and 2-year TVR (HR 0.86, 95% CI 0.75 to 0.98, p = 0.032). Instrumental variable analyses demonstrated R-ZES to be associated with lower 2-year mortality (Δ = -2.2%, 95% CI -4.3% to -0.2%, p = 0.032) and 2-year TVR (Δ = -3.3% to 95% CI -6.1% to -0.7%, p = 0.015). Acknowledging the limitations of observational analyses, this study has shown that R-ZES was associated with lower long-term TVR and mortality. These data are reassuring for the newer R-ZES and demonstrate how polymer coatings may influence the clinical performance of DES with wider implications for future DES development and design.

Research paper thumbnail of TCT-445 The prognostic significance of repeat revascularization after percutaneous coronary intervention: an analysis of 41,180 patients from the British Columbia Cardiac Registry

Journal of the American College of Cardiology, 2015

Research paper thumbnail of Embolic protection device use and its association with procedural safety and long-term outcomes following saphenous vein graft intervention: An analysis from the British Columbia Cardiac registry

Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions, Jan 20, 2015

Embolic protection devices (EPDs) have been designed and introduced to reduce distal embolization... more Embolic protection devices (EPDs) have been designed and introduced to reduce distal embolization and peri-procedural myocardial infarction during saphenous vein graft (SVG) intervention. Current guidelines give a class I recommendation to EPD use during SVG intervention when technically feasible. However, the routine use of these devices has recently been debated. We analyzed 1,359 patients undergoing isolated SVG intervention between 2008 and 2013 in the British Columbia Cardiac Registry. We analyzed (a) post-procedural TIMI flow; and (b) target vessel revascularization (TVR) and mortality at 1 and 2 years. EPD use was an independent predictor of post-procedural TIMI 2/3 flow (OR = 2.38, 95% CI: 1.51-3.74, P < 0.001). At 1 year, EPD use was an independent predictor for lower TVR (HR = 0.35, 95% CI: 0.14-0.85, P = 0.021) and a trend towards lower mortality (HR = 0.45, 95% CI: 0.18-1.10, P = 0.082). These associations were lost at 2 years where EPD use was not predictive of morta...

Research paper thumbnail of TCT-6 The optimal timing for staged non-culprit vessel intervention following primary percutaneous coronary intervention for patients with ST-elevation myocardial infarction and multivessel disease: insights from the British Columbia Cardiac Registry using decision analytical methods

Journal of the American College of Cardiology, 2017

Patients having culprit vessel intervention at primary percutaneous coronary intervention (PCI) m... more Patients having culprit vessel intervention at primary percutaneous coronary intervention (PCI) may undergo staged PCI of non-culprit disease. Whether this is performed as an inpatient (IP) or outpatient (OP) requires balancing of the risks of PCI in the vulnerable peri-infarct period versus

Research paper thumbnail of Colocalization with CD 18 Neutrophils : Alterations in the Cytoskeleton Signaling Functions of L-Selectin in

Ligation and clustering of L-selectin by Ab ("cross-linking") or physiologic ligands results in a... more Ligation and clustering of L-selectin by Ab ("cross-linking") or physiologic ligands results in activation of diverse responses that favor enhanced microvascular sequestration and emigration of neutrophils. The earliest responses include a rise in intracellular calcium, enhanced tyrosine phosphorylation, and activation of extracellular signal-regulated kinases. Additionally, cross-linking of L-selectin induces sustained shape change and activation of ␤ 2 integrins, leading to neutrophil arrest under conditions of shear flow. In this report, we examined several possible mechanisms whereby transmembrane signals from L-selectin might contribute to an increase in the microvascular retention of neutrophils and enhanced efficiency of emigration. In human peripheral blood neutrophils, cross-linking of L-selectin induced alterations in cellular biophysical properties, including a decrease in cell deformability associated with F-actin assembly and redistribution, as well as enhanced adhesion of microspheres bound to ␤ 2 integrins. L-selectin and the ␤ 2 integrin became spatially colocalized as determined by confocal immunofluorescence microscopy and fluorescence resonance energy transfer. We conclude that intracellular signals from L-selectin may enhance the microvascular sequestration of neutrophils at sites of inflammation through a combination of cytoskeletal alterations leading to cell stiffening and an increase in adhesiveness mediated through alterations in ␤ 2 integrins.

Research paper thumbnail of Where Do We Stand with Anticoagulation in Primary Pci? A Meta-Analysis of Randomized Trials Comparing Unfractionated Heparin with Bivalirudin

Canadian Journal of Cardiology

Research paper thumbnail of Radial artery pseudoaneurysms after transradial cardiac catheterisation

VASA. Zeitschrift für Gefässkrankheiten, 2016

Although uncommon, radial artery access site complications are likely to become more frequent wit... more Although uncommon, radial artery access site complications are likely to become more frequent with the increased adoption of transradial cardiac catheterisation. There is a lack of data regarding the incidence and clinical features of radial artery pseudoaneuryms. We aimed to describe the incidence, clinical features and management of radial artery pseudoaneurysms in a high-volume transradial cardiac catheterisation centre. We performed a search of the Vancouver Island Health Authority medical imaging database from 1st Jan 2008 to April 2012 looking for all radial and femoral artery pseudoaneuryms occurring after cardiac catheterisation. Hospital charts were reviewed to determine patient and procedural characteristics as well as management and outcome. There were a total of 14,968 coronary procedures performed over the four year search period, of which 13,216 (88%) were trans-radial. The incidence of radial artery pseudoaneurysm after cardiac catheterisation was 0.08%, and did not d...

Research paper thumbnail of Long-term outcomes following drug-eluting stents versus bare metal stents for primary percutaneous coronary intervention: A real-world analysis of 11,181 patients from the british columbia cardiac registry

Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions, Jan 4, 2016

Drug eluting stents (DES) are associated with reduced risk of restenosis when compared with bare ... more Drug eluting stents (DES) are associated with reduced risk of restenosis when compared with bare metal stents (BMS). Their use in ST-elevation myocardial infarction (STEMI) is debated, owing to concerns about stent thrombosis. There are limited real-world data comparing DES versus BMS in STEMI. We conducted an observational analysis in this setting and rigorously adjusted for treatment selection bias. We analyzed 11,181 consecutive patients with acute STEMI who received either DES or BMS during 2008-2014 in the British Columbia Cardiac Registry. We analyzed target vessel revascularization (TVR) and mortality at 2 years. Multivariable-adjusted, propensity-matched and inverse probability-treatment weighted analyses found DES to be associated with early and late survival up to 2 years but not TVR. However, when adjusting for measured and unmeasured confounders, instrumental variable (IV) analyses demonstrated that DES use was associated with reduced TVR up to 2 years (Δ = -6.7%, 95% CI...