Asim Shahzad cheema - Academia.edu (original) (raw)

Papers by Asim Shahzad cheema

Journal of the American Heart Association, Feb 3, 2017

Radial artery occlusion is a known complication following transradial cardiac catheterization. A ... more Radial artery occlusion is a known complication following transradial cardiac catheterization. A shorter duration of postprocedural radial clamp time may reduce radial artery occlusion (RAO) but might be associated with incomplete hemostasis. In total, 568 patients undergoing transradial diagnostic cardiac catheterization were randomly assigned to either 20 minutes (ultrashort) or 60 minutes (short) hemostatic compression time using patent hemostasis. Subsequently, clamp pressure was reduced gradually over 20 minutes. Access site hemostasis and RAO were assessed after clamp removal. Repeated assessment of RAO was determined at 1 week in 210 (37%) patients. Mean age was 64±11 years, and 30% were female. Percutaneous coronary intervention was performed in 161 patients. RAO immediately after clamp removal was documented in 14 (4.9%) and 8 (2.8%) patients in the 20- and 60-minute clamp application groups, respectively (P=0.19). The incidence of grade 1 hematoma was higher in the 20-minu...

The American journal of cardiology, 2017

Transcatheter aortic valve implantation (TAVI) is the treatment of choice for inoperable and high... more Transcatheter aortic valve implantation (TAVI) is the treatment of choice for inoperable and high-risk patients with severe aortic stenosis. Our objectives were to elucidate potential differences in clinical outcomes and safety between balloon-expandable versus self-expandable transcatheter heart valves (THV). We performed a retrospective cohort study of all transfemoral TAVI procedures in Ontario, Canada, from 2007 to 2013. Patients were categorized into either balloon-expandable or self-expandable THV groups. The primary outcomes were 30-day and 1-year death, with secondary outcomes of all-cause readmission. Safety outcomes included bleeding, permanent pacemaker implantation, need for a second THV device, postprocedural paravalvular aortic regurgitation, stroke, vascular access complication, and intensive care unit length of stay. Inverse probability of treatment-weighted regression analyses using a propensity score were used to account for differences in baseline confounders. Our...

Journal of the American College of Cardiology, 2016

Targeting reperfusion injury in the era of primary percutaneous coronary intervention-hope or hyp... more Targeting reperfusion injury in the era of primary percutaneous coronary intervention-hope or hype? (disputats).

Circulation, Nov 23, 2010

Background: Small randomized trials and meta-analyses of aspiration thrombectomy (AT) for STEMI d... more Background: Small randomized trials and meta-analyses of aspiration thrombectomy (AT) for STEMI demonstrate improved angiographic outcomes and suggest a possible reduction in mortality but an increase in stroke. We conducted an international survey of the extent and patterns of use of AT and assessed the feasibility of performing a definitive, large randomized trial. Methods: A 27-item survey was distributed to 1616 interventional cardiologists (IC) internationally through various national organizations and investigator networks. Results: A total of 425 surveys were completed (response rate 26%). AT is used routinely by 33% and selectively by 62% of IC during primary PCI. Overall, respondents use AT in 51% (standard deviation (SD) 31%) of their cases of primary PCI for STEMI. Common utilization criteria include: large thrombus (84%), TIMI 0 or 1 flow (55%), and proximal coronary artery occlusion (33%). Regarding technique, i) 79% turn on suction prior to advancing the catheter through the target lesion and ii) 81% remove the catheter from the target vessel under continuous suction. One-fifth (20%) of IC report having experienced at least one serious complication from aspiration thrombectomy, including: thrombus brought back from target vessel into left main (5%), left main dissection ( Conclusions: This is the first international survey of AT and it shows that it is used routinely by less than one-third of IC. In “real world” practice, complications related to AT are not infrequent. The data suggests that a definitive trial is needed and that there is sufficient equipoise and interest among IC such that a trial is feasible in the current era.

European heart journal, Jan 20, 2015

Manual thrombectomy has been proposed as a strategy to reduce thrombus burden during primary perc... more Manual thrombectomy has been proposed as a strategy to reduce thrombus burden during primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI). However, the effectiveness of manual thrombectomy in reducing thrombus burden is uncertain. In this substudy of the TOTAL (ThrOmbecTomy versus PCI ALone) trial, we compared the thrombus burden at the culprit lesion using optical coherence tomography (OCT) in patients treated with thrombectomy vs. PCI-alone. The TOTAL trial (N = 10 732) was an international, multicentre, randomized trial of thrombectomy (using the Export catheter, Medtronic Cardiovascular, Santa Rosa, CA, USA) in STEMI patients treated with primary PCI. The OCT substudy prospectively enrolled 214 patients from 13 sites in 5 countries. Optical coherence tomography was performed immediately after thrombectomy or PCI-alone and then repeated after stent deployment. Thrombus quantification was performed by an independent c...

Circulation. Cardiovascular interventions, 2013

S everal studies have shown the safety of MRI after coronary stenting; however, few of them inclu... more S everal studies have shown the safety of MRI after coronary stenting; however, few of them included patients soon after stenting. In this report, we describe a case of MRIinduced stent dislodgment from left main coronary artery (LMCA) 2 weeks after stenting.

Circulation: Cardiovascular Interventions, 2014

Porto et al 1 have raised 2 issues. The first issue relates to the rationale of clinical decision... more Porto et al 1 have raised 2 issues. The first issue relates to the rationale of clinical decision making and appropriateness of techniques used for percutaneous coronary intervention of the left main stenosis, and the second issue relates to the effects of MRI on the Cypher stent. Dr Lederman et al 2 are also skeptical about the stent migration observed and would like to attribute this to iatrogenic or natural causes. Dr Lederman et al 2 also share their experiment with a single 3.0×28 mm Cypher stent in a 1.5T MRI scanner that showed a deflection of 5° after an unspecified duration of exposure. The authors would like to clarify that left main lesion was angiographically significant with evidence of myocardial ischemia on noninvasive imaging to guide management decisions. In addition, the intravascular ultrasound showed a lumen cross-sectional area of 5.1 mm 2 , a left main cross-sectional area best treated by revascularization for improved long-term prognosis. 4 For the percutaneous coronary intervention technique, the angiographic and intravascular ultrasound images confirm the appropriate selection of stent length and diameter, with excellent procedural result substantiated final angiographic and intravascular ultrasound images showing complete lesion coverage including ostium, adequate stent apposition, symmetrical stent expansion, and no residual stenosis. Therefore, there remains little doubt for the immediate procedural success and absence of iatrogenic causes for observed complication. With regards to the second issue for the safety of coronary stents in the MRI environment, the authors would agree that all 316L stainless steel stents are weakly ferromagnetic, and available evidence confirms the safety of MRI for most patients after stenting. 5 However, it is important to note that interactions of stent implants with MRI environment are dependent on the strength of the magnetic field, duration of exposure, the degree of stent ferromagnetism, as well as the size, location, orientation, and geometry of the implanted stent. All confounding parameters of a clinical setting may be difficult to replicate in the experimental testing commonly used to study this phenomenon. Hug et al 6 have previously investigated movement, heating, and artifact for bare metal stents after 30 minutes of exposure in a 1.5T MRI environment and reported stent deflection in the range of 1° to 3°. Similarly, Shellock and Forder 7 reported a deflection of ≤4° for a drug-eluting stent after 20-minute exposure in the 3T MRI scanner, findings similar to those noted by Dr Lederman et al. 2 Because of the variability of interaction between different stent platforms and MRI environment, Food and Drug Administration continues to mandate extensive preclinical evaluation for MRI safety of stent implants. 8 Last, we agree with comments made by Dr Porto et al 1 and Dr Lederman et al 2 that MRI is safe for most patients with coronary stents. However, caution is advised in the immediate poststenting period for greater patient safety when a short stainless steel drug-eluting stent has been placed at an aorto-ostial location. Disclosures None.

Open heart, 2015

Public reporting of percutaneous coronary intervention (PCI) outcomes has been established in man... more Public reporting of percutaneous coronary intervention (PCI) outcomes has been established in many jurisdictions to ensure optimal delivery of care. The majority of PCI report cards examine in-hospital mortality, but relatively little is known regarding the adherence to processes of care. A modified Delphi panel comprising cardiovascular experts was assembled to develop a set of PCI quality indicators. Indicators such as prescription of aspirin, dual antiplatelet therapy, statins and smoking cessation counselling were identified to represent high-quality PCI care. Chart abstraction was performed at 13 PCI hospitals in Ontario, Canada from 2009 to 2010 with at least 200 PCI patients randomly selected from each hospital. Our study sample included 3041 patients, of whom 18% had stable coronary artery disease (CAD) and 82% had an acute coronary syndrome (ACS). Their mean age was 63±12.4 years and 29% of patients were female. Prior to PCI, 89% were prescribed aspirin, and after PCI 98.7%...

European heart journal, Jan 7, 2014

The aim of this study was to determine the effects of advanced chronic kidney disease (CKD) on ea... more The aim of this study was to determine the effects of advanced chronic kidney disease (CKD) on early and late outcomes after transcatheter aortic valve implantation (TAVI), and to evaluate the predictive factors of poorer outcomes in such patients. This was a multicentre study including a total of 2075 consecutive patients who had undergone TAVI. Patients were grouped according the estimated glomerular filtration rate as follows: CKD stage 1-2 (≥60 mL/min/1.73 m(2); n = 950), stage 3 (30-59 mL/min/1.73 m(2); n = 924), stage 4 (15-29 mL/min/1.73 m(2); n = 134) and stage 5 (<15 mL/min/1.73 m² or dialysis; n = 67). Clinical outcomes were evaluated at 30-days and at follow-up (median of 15 [6-29] months) and defined according to the VARC criteria. Advanced CKD (stage 4-5) was an independent predictor of 30-day major/life-threatening bleeding (P = 0.001) and mortality (P = 0.027), and late overall, cardiovascular and non-cardiovascular mortality (P…

Patient Preference and Adherence, 2014

Background: As ticagrelor enters into clinical use for acute coronary syndrome, it is important t... more Background: As ticagrelor enters into clinical use for acute coronary syndrome, it is important to understand patient/physician behavior in terms of appropriate use, adherence, and event rates. Methods: The Southern Saskatchewan Ticagrelor Registry is a prospective, observational, multicenter cohort study that identifies consecutive patients started on ticagrelor. We aimed to evaluate both on-and off-label use, identify characteristics of patients who prematurely stop ticagrelor, and describe patient/physician behavior contributing to inappropriate stoppage of this medication. Results: From April 2012 to September 2013, 227 patients were initiated on ticagrelor, with a mean age of 62.2±12.1 years. The participants were 66% men and had a mean follow up of 157.4±111.7 days. Seventy-four patients (32.4%) had off-label indications. Forty-seven patients (20.7%) prematurely stopped ticagrelor and were more likely to be older, women, nonwhite, present with shock, and complain of dyspnea. Twenty-six of the 47 patients stopped ticagrelor inappropriately because of patient nonadherence (18 patients) and physician advice (eight patients). A composite outcome event of death from vascular causes, myocardial infarction, or stroke occurred in 8.8% of the entire cohort and was more likely to occur in those older then 65 years, those presenting with cardiogenic shock, and those who prematurely stopped ticagrelor. Conclusion: In this real-world registry of patients started on ticagrelor, a third have off-label indications and a fifth prematurely stop the medication. Premature discontinuation was an independent predictor of major life-threatening bleeding and increased composite event rate of death from vascular causes, myocardial infarction, or stroke.

Journal of the American College of Cardiology, 2014

Journal of the American College of Cardiology, 2006

The aim of this study was to delineate the temporal profile of adventitial microvessel (Ad-MV) fo... more The aim of this study was to delineate the temporal profile of adventitial microvessel (Ad-MV) formation after stenting, its relationship to arterial wall hypoxia, and the effects of a tyrosine kinase inhibitor (TKI), SU11218, on Ad-MV and in-stent intimal hyperplasia (IH). BACKGROUND Adventitial microvessels have been reported after arterial injury; however, the underlying stimulus for this response and its relationship to IH is unknown. METHODS Coronary stenting was performed in 40 pigs randomized to SU11218 (n ϭ 20) or placebo (n ϭ 20). Vessel wall hypoxia was assessed by pimonidazole adducts and hypoxia-inducible factor (HIF)-1 alpha expression. Adventitial microvessels were quantified by threedimensional microscopic computed tomography (3D micro CT). Intimal hyperplasia was measured by intravascular ultrasound (IVUS), 3D micro CT, and morphometry. The effects of SU11218 were assessed in vitro on smooth muscle cell (SMC) and endothelial cell (EC) functions and in vivo on Ad-MV and IH. RESULTS Hypoxia was evident in the vessel wall at 48 h and persisted for four weeks. Adventitial microvessels increased significantly at one week (24 Ϯ 7 microvessels/segment) and four weeks (23 Ϯ 7 microvessels/segment) compared with uninjured arteries (16 Ϯ 2 microvessels/ segment; p Ͻ 0.001) and correlated with IH (r ϭ 0.77, p Ͻ 0.001). The TKI SU11218 inhibited platelet-derived growth factor receptor-beta phosphorylation, EC and SMC DNA synthesis, and migration in a dose-dependent manner in vitro and significantly inhibited Ad-MV (16 Ϯ 5 vs. 23 Ϯ 7 microvessels/segment in placebo, p Ͻ 0.001) and produced approximately 80% reduction in IH (0.52 Ϯ 0.51 mm 2 vs. 2.47 Ϯ 1.66 mm 2 in placebo, p Ͻ 0.001) at four weeks in vivo. CONCLUSIONS Arterial stenting causes arterial wall hypoxia followed by Ad-MV formation. The TKI SU11218 inhibits both Ad-MV formation and IH and represents a promising therapeutic agent to prevent in-stent restenosis.

Journal of the American College of Cardiology, 2002

placebo treated control) in intima/media ratio paralleled by accelerated endothelial coverage and... more placebo treated control) in intima/media ratio paralleled by accelerated endothelial coverage and reduced intimal call number. Conclusions: The combination treatment with VEGF-C adenovirus and STI571 led to a long-lasting inhibition of intimal thickening. Our study is one of the first successful examplas of gene therapy combined with pharmacological treatment and provides a novel principle to prevent intimal hyperplasia after vascular intervention.

Journal of the American College of Cardiology, 2004

S-Angiography & Interventional Cardiology 77A Angiography & Interventional Cardiology Methods: At... more S-Angiography & Interventional Cardiology 77A Angiography & Interventional Cardiology Methods: Atherectomy probes from 17 patients with coronary ISR (n=10; time post stenting 5±3 months) and with peripheral ISR (n=7; 7±3 months) versus those from 10 patients with primary lesions were immunohistochemically examined for the presence of the determinants CD34, AC133, S100, GFAP, NSE, NGFR and α-smooth muscle (SM) actin followed by computer-assisted morphometry. Results: ISR probes demonstrated pronounced hypercellularity (942±318 cells/mm 2) compared to primary lesions (347±120 cells/mm 2 , P<0.001). α-SM actin positive cells occupied 67% of intimal cells in ISR. Expression of endothelial progenitor cells (

Journal of the American College of Cardiology, Jan 8, 2011

The objective was to define the characteristics of a real-world patient population treated with t... more The objective was to define the characteristics of a real-world patient population treated with transcatheter aortic valve implantation (TAVI), regardless of technology or access route, and to evaluate their clinical outcome over the mid to long term.

JACC: Cardiovascular Interventions, 2014

Objectives The aim of this study was to determine the impact of new-onset persistent left bundle ... more Objectives The aim of this study was to determine the impact of new-onset persistent left bundle branch block (NOP-LBBB) on late outcomes after transcatheter aortic valve implantation (TAVI). Background The impact of NOP-LBBB after TAVI remains controversial. Methods A total of 668 consecutive patients who underwent TAVI with a balloon-expandable valve without pre-existing LBBB or permanent pacemaker implantation (PPI) were included. Electrocardiograms were obtained at baseline, immediately after the procedure, and daily until hospital discharge. Patients were followed at 1, 6, and 12 months and yearly thereafter. Results New-onset LBBB occurred in 128 patients (19.2%) immediately after TAVI and persisted at hospital discharge in 79 patients (11.8%). At a median follow-up of 13 months (range 3 to 27 months), there were no differences in mortality rate between the NOP-LBBB and no NOP-LBBB groups (27.8% vs. 28.4%; adjusted-hazard ratio: 0.87 [95% confidence interval (CI): 0.55 to 1.37]; p ¼ 0.54). There were no differences between groups regarding cardiovascular mortality (p ¼ 0.82), sudden death (p ¼ 0.87), rehospitalizations for all causes (p ¼ 0.11), or heart failure (p ¼ 0.55). NOP-LBBB was the only factor associated with an increased rate of PPI during the follow-up period (13.9% vs. 3.0%; hazard ratio: 4.29 [95% CI: 2.03 to 9.07], p < 0.001. NOP-LBBB was also associated with a lack of left ventricular ejection fraction improvement and poorer New York Heart Association functional class at follow-up (p < 0.02 for both). Conclusions NOP-LBBB occurred in w1 of 10 patients who had undergone TAVI with a balloonexpandable valve. NOP-LBBB was associated with a higher rate of PPI, a lack of improvement in left ventricular ejection fraction, and a poorer functional status, but did not increase the risk of global or cardiovascular mortality or rehospitalizations at 1-year follow-up.

The International Journal of Medical Robotics and Computer Assisted Surgery, 2011

Despite the recent advances in catheter design and technology, intra-cardiac navigation during el... more Despite the recent advances in catheter design and technology, intra-cardiac navigation during electrophysiology procedures remains challenging. Incorporation of imaging along with magnetic or robotic guidance may improve navigation accuracy and procedural safety. In the present study, the in vivo performance of a novel remote controlled Robot Assisted Cardiac Navigation System (RACN) was evaluated in a porcine model. The navigation catheter and target sensor were advanced to the right atrium using fluoroscopic and intra-cardiac echo guidance. The target sensor was positioned at three target locations in the right atrium (RA) and the navigation task was completed by an experienced physician using both manual and RACN guidance. The navigation time, final distance between the catheter tip and target sensor, and variability in final catheter tip position were determined and compared for manual and RACN guided navigation. The experiments were completed in three animals and five measurements recorded for each target location. The mean distance (mm) between catheter tip and target sensor at the end of the navigation task was significantly less using RACN guidance compared with manual navigation (5.02 ± 0.31 vs. 9.66 ± 2.88, p = 0.050 for high RA, 9.19 ± 1.13 vs. 13.0 ± 1.00, p = 0.011 for low RA and 6.77 ± 0.59 vs. 15.66 ± 2.51, p = 0.003 for tricuspid valve annulus). The average time (s) needed to complete the navigation task was significantly longer by RACN guided navigation compared with manual navigation (43.31 ± 18.19 vs. 13.54 ± 1.36, p = 0.047 for high RA, 43.71 ± 11.93 vs. 22.71 ± 3.79, p = 0.043 for low RA and 37.84 ± 3.71 vs. 16.13 ± 4.92, p = 0.003 for tricuspid valve annulus. RACN guided navigation resulted in greater consistency in performance compared with manual navigation as evidenced by lower variability in final distance measurements (0.41 vs. 0.99 mm, p = 0.04). This study demonstrated the safety and feasibility of the RACN system for cardiac navigation. The results demonstrated that RACN performed comparably with manual navigation, with improved precision and consistency for targets located in and near the right atrial chamber.

Heart, 2009

A 57-year-old symptomatic woman underwent emergency stenting of an isolated ostial lesion (video ... more A 57-year-old symptomatic woman underwent emergency stenting of an isolated ostial lesion (video 1) in an unprotected left main coronary artery (LMCA) after becoming hypotensive and ischaemic during routine angiography. A 3.5×12 Taxus stent was deployed using the stent overhang technique (intentional protrusion of one to two stent struts into the aorta) and its …

Clinical Cardiology, 2007

Circulation, 2013

Background— Very few data exist on the clinical impact of permanent pacemaker implantation (PPI) ... more Background— Very few data exist on the clinical impact of permanent pacemaker implantation (PPI) after transcatheter aortic valve implantation. The objective of this study was to assess the impact of PPI after transcatheter aortic valve implantation on late outcomes in a large cohort of patients. Methods and Results— A total of 1556 consecutive patients without prior PPI undergoing transcatheter aortic valve implantation were included. Of them, 239 patients (15.4%) required a PPI within the first 30 days after transcatheter aortic valve implantation. At a mean follow-up of 22±17 months, no association was observed between the need for 30-day PPI and all-cause mortality (hazard ratio, 0.98; 95% confidence interval, 0.74–1.30; P =0.871), cardiovascular mortality (hazard ratio, 0.81; 95% confidence interval, 0.56–1.17; P =0.270), and all-cause mortality or rehospitalization for heart failure (hazard ratio, 1.00; 95% confidence interval, 0.77–1.30; P =0.980). A lower rate of unexpected ...