Robert G Hauser - Academia.edu (original) (raw)

Papers by Robert G Hauser

Europace, Nov 27, 2009

An estimated 10 000-15 000 pacemaker and implantable cardioverter-defibrillator (ICD) leads are e... more An estimated 10 000-15 000 pacemaker and implantable cardioverter-defibrillator (ICD) leads are extracted annually worldwide using specialized tools that disrupt encapsulating fibrous tissue. Additional information is needed regarding the safety of the devices that have been approved for lead extraction. The aim of this study was to determine whether complications due to device-assisted lead extraction might be more hazardous than published data suggest, and whether procedural safety precautions are effective. Methods and results We searched the US Food and Drug Administration's (FDA) Manufacturers and User Defined Experience (MAUDE) database from 1995 to 2008 using the search terms 'lead extraction and death' and 'lead extraction and injury'. Additional product specific searches were performed for the terms 'death' and 'injury'. Between 1995 and 2008, 57 deaths and 48 serious cardiovascular injuries associated with device-assisted lead extraction were reported to the FDA. Owing to underreporting, the FDA database does not contain all adverse events that occurred during this period. Of the 105 events, 27 deaths and 13 injuries occurred in 2007-2008. During these 2 years, 23 deaths were linked with excimer laser or mechanical dilator sheath extractions. The majority of deaths and injuries involved ICD leads, and most were caused by lacerations of the right atrium, superior vena cava, or innominate vein. Overall, 62 patients underwent emergency surgical repair of myocardial perforations and venous lacerations and 35 (56%) survived. Conclusion These findings suggest that device-assisted lead extraction is a high-risk procedure and that serious complications including death may not be mitigated by emergency surgery. However, skilled standby cardiothoracic surgery is essential when performing pacemaker and ICD lead extractions. Although the incidence of these complications is unknown, the results of our study imply that device-assisted lead extractions should be performed by highly qualified physicians and their teams in specialized centres.

Journal of the American College of Cardiology, 2010

This study was designed to define more completely the clinical spectrum and consequences of stres... more This study was designed to define more completely the clinical spectrum and consequences of stress cardiomyopathy (SC) beyond the acute event. Background Stress cardiomyopathy is a recently recognized condition characterized by transient cardiac dysfunction with ventricular ballooning. Methods Clinical profile and outcome were prospectively assessed in 136 consecutive SC patients. Results Patients were predominantly women (n ϭ 130; 96%), but 6 were men (4%). Ages were 32 to 94 years (mean age 68 Ϯ 13 years); 13 (10%) were Յ50 years of age. In 121 patients (89%), SC was precipitated by intensely stressful emotional (n ϭ 64) or physical (n ϭ 57) events, including 22 associated with sympathomimetic drugs or medical/surgical procedures; 15 other patients (11%) had no evident stress trigger. Twenty-five patients (18%) were taking beta-blockers at the time of SC events. Three diverse ventricular contraction patterns were defined by cardiovascular magnetic resonance (CMR) imaging, usually with rapid return to normal systolic function, although delayed Ͼ2 months in 5%. Right and/or left ventricular thrombi were identified in 5 patients (predominantly by CMR imaging), including 2 with embolic events. Three patients (2%) died in-hospital and 116 (85%) have survived, including 5% with nonfatal recurrent SC events. All-cause mortality during follow-up exceeded a matched general population (p ϭ 0.016) with most deaths occurring in the first year. Conclusions In this large SC cohort, the clinical spectrum was heterogeneous with about one-third either male, Յ50 years of age, without a stress trigger, or with in-hospital death, nonfatal recurrence, embolic stroke, or delayed normalization of ejection fraction. Beta-blocking drugs were not absolutely protective and SC was a marker for increased noncardiac mortality. These data support expanded management and surveillance strategies including CMR imaging and consideration for anticoagulation. (

American Heart Journal, Sep 1, 2017

Aims-Recent data from the National Cardiovascular Data Registry indicate that women with STsegmen... more Aims-Recent data from the National Cardiovascular Data Registry indicate that women with STsegment-elevation myocardial infarction (STEMI) continue to have higher mortality and reported delays in treatment compared to men. We aimed to determine whether the sex difference in mortality exists when treatment disparities are reduced. Methods and Results-Using a prospective regional percutaneous-coronary-intervention (PCI)-based STEMI system database with a standardized STEMI protocol, we evaluated baseline characteristics, treatment and clinical outcomes of STEMI patients stratified by sex. From March 2003 to January 2016, 4918 consecutive STEMI patients presented to the Minneapolis Heart Institute at Abbott Northwestern Hospital regional STEMI system including 1416 (28.8%) women. Compared to men, women were older (68.4 vs 60.9 years) with higher rates of hypertension (66.7 vs 55.7%), diabetes (21.7 vs 17.4%) and cardiogenic shock (11.5 vs 8.0%) (all P<0.001). Pre-revascularization medications and PCI were performed with same frequencies, but women were less likely to receive statin or anti-platelet therapy at discharge. After age-adjustment, women had similar in-hospital mortality to men (5.1% vs 4.8%, P=0.60), despite slightly longer door-to-balloon time (95 vs 92 mins, P=0.004). Five-year follow-up confirmed absence of a sex disparity in age-adjusted survival post-STEMI. Conclusions-Previously reported treatment disparities between men and women are diminished in a regional PCI-based STEMI system using a standardized STEMI protocol. No sex differences in short-term or long-term age-adjusted mortality are present in this registry despite

Journal of Interventional Cardiac Electrophysiology, 2022

Journal of Interventional Cardiac Electrophysiology, 2021

Purpose We hypothesized that data in manufacturers’ product performance reports (PPRs) can provid... more Purpose We hypothesized that data in manufacturers’ product performance reports (PPRs) can provide clinically valuable ICD and cardiac resynchronization defibrillator (CRT-D) reliability and longevity information. Methods Data were obtained from 2019 PPRs. Kaplan-Meier (K-M) probabilities of freedom from malfunction, normal battery depletion (NBD), and NBD + malfunction were calculated for ICD and CRT-D pulse generators (PGs) with LiMnO2 or LiSVO/CFx batteries marketed in the USA from 2010 to 2019 and compared using the log-rank test. Malfunctions (MAL) included PGs that were found outside specifications. Results Study population included 1,149,803 ICD and CRT-D PGs: Abbott (ABT; 35.1%), Biotronik (BIO; 4.6%), Boston Scientific (BSC; 23.5%), and Medtronic (MDT; 36.9%). Significant differences in reliability (p < 0.001), defined by freedom from MAL, were found between manufacturers; the majority of 6808 MAL occurred in ABT devices (n = 4045; 59.4%), followed by BSC (n = 2384; 35.0...

Journal of the American College of Cardiology, 2015

background: Women with STEMI are less likely to receive guideline recommended medications and rep... more background: Women with STEMI are less likely to receive guideline recommended medications and reperfusion therapy compared to men. They have longer times to treatment and higher mortality. Whether the higher mortality is related to treatment disparities or sexrelated biological differences is controversial. methods: Using a comprehensive prospective regional percutaneous coronary intervention (PCI) based STEMI system database with a standardized STEMI protocol, we evaluated demographic information, risk factors, treatment and clinical outcomes of STEMI patients stratified by sex. Results: From 3/03 to 1/13, 3,785 consecutive STEMI patients presented to the Minneapolis Heart Institute at Abbott Northwestern Hospital regional STEMI system including 1088 (28.8%) women. Women were older with higher rates of hypertension, diabetes and cardiogenic shock but lower rates of previous MI and revascularization (table). After age-adjustment, women had similar outcomes to men including revascularization, door-to-balloon times, and in-hospital mortality. Sex was not a significant predictor of in-hospital mortality in a multivariate model. conclusion: The previously reported disparities between men and women are not evident in a Regional PCI-based STEMI system with a standardized STEMI protocol. These results suggest that STEMI healthcare disparities and mortality in women can be improved using STEMI protocols and systems.

Journal of the American College of Cardiology, 2012

Background: Chronic right ventricular pacing (RVP) may cause left ventricular (LV) remodeling and... more Background: Chronic right ventricular pacing (RVP) may cause left ventricular (LV) remodeling and heart failure (HF). However guidelines do not recommend cardiac resynchronization defibrillators (CRT-D) for patients without HF who need frequent ventricular pacing. We thus examined the effect of RVP on survival (Surv) in our ICD patients who have LV dysfunction (ejection fraction (EF) ≤35%). Methods: Patients were adults≥18yrs and followed from 2000-2011. The 3 groups were: 1-Patients with single (S) or dual (D) chamber ICDs who had RVP≥50% (S+D≥50%); 2-Patients with S or D ICDs who had RVP<50% (S+D<50%); 3-Patients who had CRT-D. Cumulative % RVP were based on interrogations. Surv were estimated by the Kaplan-Meier method and compared by the logrank test. A Cox proportional hazards model assessed the effects of clinical variables on Surv. Results: Average age and EF of 1248 patients was 67.4 ± 12.0 years and 23.9% ± 7.2. The Surv of the 3 groups during mean follow-up of 3.7 ± 2.2 years are shown in the figure (unadjusted p<0.0001). The risk adjusted proportional hazards regression (HR±95%) revealed: S+D <50% relative to CRT: HR-0.99 [0.52-1.90] p=0.98; S+D≥50% relative to CRT: HR-2.12 [1.00-4.52] p=0.05; and S+D<50% relative to S+D≥50%: HR-0.47 [0.26-0.84] p=0.01. Conclusions: Chronic RVP is associated with significantly reduced survival. This adverse effect of RVP on survival was not seen in CRT-D patients. Thus CRT-D appears appropriate for ICD patients who have LVD and require chronic ventricular pacing. CORE Metadata, citation and similar papers at core.ac.uk

Journal of the American College of Cardiology, 2012

Background: About 100,000 U.S. patients have Riata and Riata ST defibrillator leads (St. Jude Med... more Background: About 100,000 U.S. patients have Riata and Riata ST defibrillator leads (St. Jude Medical, Inc., Sylmar). Reports suggest that Riata and Riata ST leads are prone to a unique failure mechanism whereby the conductor cables wear through the silicone insulation from inside-out and appear outside the lead body (externalized cables) on fluoroscopy or x-ray. Little is known of this defect, its clinical signs, adverse events, or implications for patient management. Accordingly, we assessed the manufacturer's analyses of explanted leads that had inside-out insulation defects. Methods: The FDA MAUDE database was searched for the manufacturer's reports describing Riata inside-out insulation defects. Data were extracted for failure signs, documented lead defects, and complications. Results: The search identified 105 returned Riata and Riata ST leads that were found by the manufacturer to have inside-out insulation defects; average implant time was 62.1±18.6 mos (range: 15-108 months). A total of 222 insulation defects (2.11/lead) were found, including 143 insideout insulation defects (1.36/lead), 34 outside-in defects (0.32/lead), 36 defects caused by the ICD can (0.34/lead), and 9 unspecified defects. Of the 143 inside-out insulation defects, 93 (65.0%) were distal to the proximal shocking coil and 33 (31%) had exposed conductor cables. The ETFE high voltage cable insulation was abraded in 22 of 43 (51.2%) leads reported. Clinical signs of failure included: noise/oversensing (45/105; 42.8%); impedance changes (23/105; 21.9%); high threshold or loss of capture (11/105; 10.4%); and other (26/105; 24.7%) including 7 externalized cables (6.6%). Inappropriate shocks affected 29 patients (27.6%), and one death was associated with a can abrasion and truncated high voltage shock. Conclusions: Explanted Riata and Riata ST leads were found to have multiple inside-out insulation defects which often involved the low voltage conductors. Thus lead noise and inappropriate shocks were common. High voltage cable insulation abrasion also occurred. These observations suggest that Riata leads may have more widespread damage than can be detected by fluoroscopic examination.

JAMA, 1999

Context Hypertrophic cardiomyopathy (HCM) has been regarded as a disease that causes substantial ... more Context Hypertrophic cardiomyopathy (HCM) has been regarded as a disease that causes substantial disability, with annual mortality rates of up to 6%, based largely on reports from tertiary referral centers. Objective To assess the clinical course of HCM in a patient cohort more closely resembling the true disease state. Design Retrospective cohort study. Setting A regional cohort from Minnesota and adjoining regions, free of referral center bias, studied at Minneapolis Heart Institute.

JACC: Cardiovascular Interventions, 2010

Objectives The objectives of this study were: 1) to delineate the temporal course of histopatholo... more Objectives The objectives of this study were: 1) to delineate the temporal course of histopathologic healing as the left atrial appendage (LAA) is obliterated by a mechanical device; and 2) to compare this process with other intravascular and intracardiac implanted technologies. Background Intracardiac device healing is incompletely understood. We thus studied the histopathology of device-based LAA obliteration. Methods Nine dog hearts were examined over time after LAA device placement and results were compared with human hearts with prior LAA obliteration using the same device. Results At 3 days in dogs, atrial surfaces were covered by fibrin, which sealed gaps between the LA wall and the device and filled the LA appendage cavity. At 45 days, endothelial cells covered the endocardial surface with underlying smooth muscle cells that sealed the device-LA interface. Regions with prior thrombus were replaced by endocardium surrounding the device membrane. Disorganized thrombus remained in the LAA body and at the periphery near the appendage walls. Mild inflammation was observed as thrombus resorbed. By 90 days, a complete endocardial lining covered the former LAA ostium. Organizing thrombus had become connective tissue, with no residual inflammation. The human necropsy hearts had similar findings. In these 4 hearts (139, 200, 480, and 852 days after implant), the ostial fabric membrane was covered with endocardium. The appendage surface contained organizing thrombus with minimal inflammation. Organizing fibrous tissue was inside the LAA cavity, prominent near the atrial wall. The LAA interior contained organizing thrombus. Conclusions This intracardiac device integration study delineated healing stages of early thrombus deposition, thrombus organization, inflammation and granulation tissue, final healing by connective tissue, and endocardialization without inflammation. These observations may yield insight into cellular healing processes in other cardiac devices.

Heart Rhythm, 2010

BACKGROUND The Medtronic Sprint Fidelis high-voltage implantable cardioverter-defibrillator (ICD)... more BACKGROUND The Medtronic Sprint Fidelis high-voltage implantable cardioverter-defibrillator (ICD) lead is prone to fracture. The majority of fractures involve the pace-sense (P/S) conductors and may result in multiple inappropriate shocks. The Medtronic lead integrity alert (LIA) algorithm was designed to improve early detection of transient P/S conductor fractures and to decrease the incidence and number of inappropriate shocks. OBJECTIVE The purpose of this prospective single-center study was to assess the effectiveness of the LIA algorithm for warning patients of an impending Sprint Fidelis P/S conductor fracture and for decreasing the incidence and number of inappropriate shocks. METHODS The study population included all patients who had Sprint Fidelis leads and Medtronic ICD pulse generators that were implanted and followed at the Minneapolis Heart Institute. Patients were evaluated in the clinic every 3 to 4 months or by remote monitoring using the Medtronic CareLink system. When the LIA algorithm was released in August 2008, the RAMware was downloaded to the pulse generator of all patients with the Sprint Fidelis lead. Patients and family members received educational materials and were given a demonstration of the audible alerts.

Europace, 2012

Riata ST Optim TM and Durata ICD leads have failed due to insulation abrasions. Optim TM did not ... more Riata ST Optim TM and Durata ICD leads have failed due to insulation abrasions. Optim TM did not prevent these abrasions, which developed ≤4 years after implant. Studies are needed to determine the incidence of these failures and their clinical implications.

Circulation: Cardiovascular Quality and Outcomes, 2012

Background— Postmarket medical device surveillance in the United States depends largely on volunt... more Background— Postmarket medical device surveillance in the United States depends largely on voluntary reporting of adverse events. Consequently, early safety signals may be missed, exposing patients to potentially hazardous products. The aim of this study was to assess the feasibility of using an automated safety surveillance tool to detect early signals that a marketed implantable cardiac device was underperforming. Methods and Results— For this purpose, we performed simulated prospective monthly full-cohort and propensity-matched comparative survival analyses on our 3-center database of Sprint Fidelis and Quattro Secure implantable cardioverter-defibrillator leads, using a commercially available automated surveillance tool that was preset to trigger an alert if the log rank probability value was <0.05. During the study, 84 of 1035 Fidelis (8.1%) and 23 of 1675 Quattro (1.4%) leads failed. The simulated full-cohort analysis triggered a sustained alert for Fidelis leads beginning ...

Angiology, 2013

The impact of peripheral artery disease (PAD) on survival in implantable cardioverter defibrillat... more The impact of peripheral artery disease (PAD) on survival in implantable cardioverter defibrillator (ICD) patients is poorly understood. Thus, we assessed the risk of PAD in our adult ICD patients with left ventricular dysfunction (ejection fraction [EF] ≤35%). Survival was estimated with Kaplan-Meier method and compared by the log-rank test; a Cox proportional hazards model assessed the effects of clinical variables on survival. Average age and EF of 1399 patients were 67.0 ± 12.1 years and 23.8% ± 7.2%, respectively. The ICD patients with PAD had significantly worse survival than those without (unadjusted P < .0001). The multivariate predictors of survival at implant were (hazard ratio, HR [95% confidence interval]) age (HR 1.05 [1.04-1.07] P < .0001), PAD (HR 2.07 [1.53-2.80] P < .0001), class III/IV heart failure (HR 1.36 [1.06-1.76] P = .016), creatinine 1.4-2.0 mg/dL (HR 1.36 [1.05-1.76] P = .019), and creatinine ≥2.0 mg/dL (HR 2.01 [1.42-2.85] P < .0001). The PAD ...

The American Journal of Cardiology, 2008

Two patients with hypertrophic cardiomyopathy are reported from the recent experience of the Hype... more Two patients with hypertrophic cardiomyopathy are reported from the recent experience of the Hypertrophic Cardiomyopathy Center of the Minneapolis Heart Institute Foundation, demonstrating limitations in the risk stratification algorithm currently used for this disease. One patient, an asymptomatic 21-year-old male college student, was prophylactically implanted with a cardioverter-defibrillator. This decision was based largely on the presence of apparent extensive myocardial fibrosis identified by contrast-enhanced cardiovascular magnetic resonance imaging, currently not considered a risk factor in this disease. Fifteen months later, ventricular fibrillation was interrupted by an appropriate defibrillator shock. The other patient, an asymptomatic 15-year-old male subject without any apparent highrisk markers, died suddenly at home. Necropsy examination of the heart identified scarring confined to portions of both left ventricular papillary muscles, possibly representing a substrate for ventricular tachyarrhythmias. In conclusion, these 2 cases demonstrate that present strategies for assessing high-risk status in hypertrophic cardiomyopathy are inadequate to identify all such patients. However, while the anecdotal nature of these observations cannot yet justify altering the general guidelines for implantation of defibrillators for the primary prevention of sudden death related to hypertrophic cardiomyopathy, 1 of our 2 cases suggests a future role for contrast-enhanced cardiovascular magnetic resonance in the risk stratification of this complex disease.

Journal of the American College of Cardiology, Mar 1, 2015

background: Women with STEMI are less likely to receive guideline recommended medications and rep... more background: Women with STEMI are less likely to receive guideline recommended medications and reperfusion therapy compared to men. They have longer times to treatment and higher mortality. Whether the higher mortality is related to treatment disparities or sexrelated biological differences is controversial. methods: Using a comprehensive prospective regional percutaneous coronary intervention (PCI) based STEMI system database with a standardized STEMI protocol, we evaluated demographic information, risk factors, treatment and clinical outcomes of STEMI patients stratified by sex. Results: From 3/03 to 1/13, 3,785 consecutive STEMI patients presented to the Minneapolis Heart Institute at Abbott Northwestern Hospital regional STEMI system including 1088 (28.8%) women. Women were older with higher rates of hypertension, diabetes and cardiogenic shock but lower rates of previous MI and revascularization (table). After age-adjustment, women had similar outcomes to men including revascularization, door-to-balloon times, and in-hospital mortality. Sex was not a significant predictor of in-hospital mortality in a multivariate model. conclusion: The previously reported disparities between men and women are not evident in a Regional PCI-based STEMI system with a standardized STEMI protocol. These results suggest that STEMI healthcare disparities and mortality in women can be improved using STEMI protocols and systems.

Europace, Nov 27, 2009

An estimated 10 000-15 000 pacemaker and implantable cardioverter-defibrillator (ICD) leads are e... more An estimated 10 000-15 000 pacemaker and implantable cardioverter-defibrillator (ICD) leads are extracted annually worldwide using specialized tools that disrupt encapsulating fibrous tissue. Additional information is needed regarding the safety of the devices that have been approved for lead extraction. The aim of this study was to determine whether complications due to device-assisted lead extraction might be more hazardous than published data suggest, and whether procedural safety precautions are effective. Methods and results We searched the US Food and Drug Administration's (FDA) Manufacturers and User Defined Experience (MAUDE) database from 1995 to 2008 using the search terms 'lead extraction and death' and 'lead extraction and injury'. Additional product specific searches were performed for the terms 'death' and 'injury'. Between 1995 and 2008, 57 deaths and 48 serious cardiovascular injuries associated with device-assisted lead extraction were reported to the FDA. Owing to underreporting, the FDA database does not contain all adverse events that occurred during this period. Of the 105 events, 27 deaths and 13 injuries occurred in 2007-2008. During these 2 years, 23 deaths were linked with excimer laser or mechanical dilator sheath extractions. The majority of deaths and injuries involved ICD leads, and most were caused by lacerations of the right atrium, superior vena cava, or innominate vein. Overall, 62 patients underwent emergency surgical repair of myocardial perforations and venous lacerations and 35 (56%) survived. Conclusion These findings suggest that device-assisted lead extraction is a high-risk procedure and that serious complications including death may not be mitigated by emergency surgery. However, skilled standby cardiothoracic surgery is essential when performing pacemaker and ICD lead extractions. Although the incidence of these complications is unknown, the results of our study imply that device-assisted lead extractions should be performed by highly qualified physicians and their teams in specialized centres.

Journal of the American College of Cardiology, 2010

This study was designed to define more completely the clinical spectrum and consequences of stres... more This study was designed to define more completely the clinical spectrum and consequences of stress cardiomyopathy (SC) beyond the acute event. Background Stress cardiomyopathy is a recently recognized condition characterized by transient cardiac dysfunction with ventricular ballooning. Methods Clinical profile and outcome were prospectively assessed in 136 consecutive SC patients. Results Patients were predominantly women (n ϭ 130; 96%), but 6 were men (4%). Ages were 32 to 94 years (mean age 68 Ϯ 13 years); 13 (10%) were Յ50 years of age. In 121 patients (89%), SC was precipitated by intensely stressful emotional (n ϭ 64) or physical (n ϭ 57) events, including 22 associated with sympathomimetic drugs or medical/surgical procedures; 15 other patients (11%) had no evident stress trigger. Twenty-five patients (18%) were taking beta-blockers at the time of SC events. Three diverse ventricular contraction patterns were defined by cardiovascular magnetic resonance (CMR) imaging, usually with rapid return to normal systolic function, although delayed Ͼ2 months in 5%. Right and/or left ventricular thrombi were identified in 5 patients (predominantly by CMR imaging), including 2 with embolic events. Three patients (2%) died in-hospital and 116 (85%) have survived, including 5% with nonfatal recurrent SC events. All-cause mortality during follow-up exceeded a matched general population (p ϭ 0.016) with most deaths occurring in the first year. Conclusions In this large SC cohort, the clinical spectrum was heterogeneous with about one-third either male, Յ50 years of age, without a stress trigger, or with in-hospital death, nonfatal recurrence, embolic stroke, or delayed normalization of ejection fraction. Beta-blocking drugs were not absolutely protective and SC was a marker for increased noncardiac mortality. These data support expanded management and surveillance strategies including CMR imaging and consideration for anticoagulation. (

American Heart Journal, Sep 1, 2017

Aims-Recent data from the National Cardiovascular Data Registry indicate that women with STsegmen... more Aims-Recent data from the National Cardiovascular Data Registry indicate that women with STsegment-elevation myocardial infarction (STEMI) continue to have higher mortality and reported delays in treatment compared to men. We aimed to determine whether the sex difference in mortality exists when treatment disparities are reduced. Methods and Results-Using a prospective regional percutaneous-coronary-intervention (PCI)-based STEMI system database with a standardized STEMI protocol, we evaluated baseline characteristics, treatment and clinical outcomes of STEMI patients stratified by sex. From March 2003 to January 2016, 4918 consecutive STEMI patients presented to the Minneapolis Heart Institute at Abbott Northwestern Hospital regional STEMI system including 1416 (28.8%) women. Compared to men, women were older (68.4 vs 60.9 years) with higher rates of hypertension (66.7 vs 55.7%), diabetes (21.7 vs 17.4%) and cardiogenic shock (11.5 vs 8.0%) (all P<0.001). Pre-revascularization medications and PCI were performed with same frequencies, but women were less likely to receive statin or anti-platelet therapy at discharge. After age-adjustment, women had similar in-hospital mortality to men (5.1% vs 4.8%, P=0.60), despite slightly longer door-to-balloon time (95 vs 92 mins, P=0.004). Five-year follow-up confirmed absence of a sex disparity in age-adjusted survival post-STEMI. Conclusions-Previously reported treatment disparities between men and women are diminished in a regional PCI-based STEMI system using a standardized STEMI protocol. No sex differences in short-term or long-term age-adjusted mortality are present in this registry despite

Journal of Interventional Cardiac Electrophysiology, 2022

Journal of Interventional Cardiac Electrophysiology, 2021

Purpose We hypothesized that data in manufacturers’ product performance reports (PPRs) can provid... more Purpose We hypothesized that data in manufacturers’ product performance reports (PPRs) can provide clinically valuable ICD and cardiac resynchronization defibrillator (CRT-D) reliability and longevity information. Methods Data were obtained from 2019 PPRs. Kaplan-Meier (K-M) probabilities of freedom from malfunction, normal battery depletion (NBD), and NBD + malfunction were calculated for ICD and CRT-D pulse generators (PGs) with LiMnO2 or LiSVO/CFx batteries marketed in the USA from 2010 to 2019 and compared using the log-rank test. Malfunctions (MAL) included PGs that were found outside specifications. Results Study population included 1,149,803 ICD and CRT-D PGs: Abbott (ABT; 35.1%), Biotronik (BIO; 4.6%), Boston Scientific (BSC; 23.5%), and Medtronic (MDT; 36.9%). Significant differences in reliability (p < 0.001), defined by freedom from MAL, were found between manufacturers; the majority of 6808 MAL occurred in ABT devices (n = 4045; 59.4%), followed by BSC (n = 2384; 35.0...

Journal of the American College of Cardiology, 2015

background: Women with STEMI are less likely to receive guideline recommended medications and rep... more background: Women with STEMI are less likely to receive guideline recommended medications and reperfusion therapy compared to men. They have longer times to treatment and higher mortality. Whether the higher mortality is related to treatment disparities or sexrelated biological differences is controversial. methods: Using a comprehensive prospective regional percutaneous coronary intervention (PCI) based STEMI system database with a standardized STEMI protocol, we evaluated demographic information, risk factors, treatment and clinical outcomes of STEMI patients stratified by sex. Results: From 3/03 to 1/13, 3,785 consecutive STEMI patients presented to the Minneapolis Heart Institute at Abbott Northwestern Hospital regional STEMI system including 1088 (28.8%) women. Women were older with higher rates of hypertension, diabetes and cardiogenic shock but lower rates of previous MI and revascularization (table). After age-adjustment, women had similar outcomes to men including revascularization, door-to-balloon times, and in-hospital mortality. Sex was not a significant predictor of in-hospital mortality in a multivariate model. conclusion: The previously reported disparities between men and women are not evident in a Regional PCI-based STEMI system with a standardized STEMI protocol. These results suggest that STEMI healthcare disparities and mortality in women can be improved using STEMI protocols and systems.

Journal of the American College of Cardiology, 2012

Background: Chronic right ventricular pacing (RVP) may cause left ventricular (LV) remodeling and... more Background: Chronic right ventricular pacing (RVP) may cause left ventricular (LV) remodeling and heart failure (HF). However guidelines do not recommend cardiac resynchronization defibrillators (CRT-D) for patients without HF who need frequent ventricular pacing. We thus examined the effect of RVP on survival (Surv) in our ICD patients who have LV dysfunction (ejection fraction (EF) ≤35%). Methods: Patients were adults≥18yrs and followed from 2000-2011. The 3 groups were: 1-Patients with single (S) or dual (D) chamber ICDs who had RVP≥50% (S+D≥50%); 2-Patients with S or D ICDs who had RVP<50% (S+D<50%); 3-Patients who had CRT-D. Cumulative % RVP were based on interrogations. Surv were estimated by the Kaplan-Meier method and compared by the logrank test. A Cox proportional hazards model assessed the effects of clinical variables on Surv. Results: Average age and EF of 1248 patients was 67.4 ± 12.0 years and 23.9% ± 7.2. The Surv of the 3 groups during mean follow-up of 3.7 ± 2.2 years are shown in the figure (unadjusted p<0.0001). The risk adjusted proportional hazards regression (HR±95%) revealed: S+D <50% relative to CRT: HR-0.99 [0.52-1.90] p=0.98; S+D≥50% relative to CRT: HR-2.12 [1.00-4.52] p=0.05; and S+D<50% relative to S+D≥50%: HR-0.47 [0.26-0.84] p=0.01. Conclusions: Chronic RVP is associated with significantly reduced survival. This adverse effect of RVP on survival was not seen in CRT-D patients. Thus CRT-D appears appropriate for ICD patients who have LVD and require chronic ventricular pacing. CORE Metadata, citation and similar papers at core.ac.uk

Journal of the American College of Cardiology, 2012

Background: About 100,000 U.S. patients have Riata and Riata ST defibrillator leads (St. Jude Med... more Background: About 100,000 U.S. patients have Riata and Riata ST defibrillator leads (St. Jude Medical, Inc., Sylmar). Reports suggest that Riata and Riata ST leads are prone to a unique failure mechanism whereby the conductor cables wear through the silicone insulation from inside-out and appear outside the lead body (externalized cables) on fluoroscopy or x-ray. Little is known of this defect, its clinical signs, adverse events, or implications for patient management. Accordingly, we assessed the manufacturer's analyses of explanted leads that had inside-out insulation defects. Methods: The FDA MAUDE database was searched for the manufacturer's reports describing Riata inside-out insulation defects. Data were extracted for failure signs, documented lead defects, and complications. Results: The search identified 105 returned Riata and Riata ST leads that were found by the manufacturer to have inside-out insulation defects; average implant time was 62.1±18.6 mos (range: 15-108 months). A total of 222 insulation defects (2.11/lead) were found, including 143 insideout insulation defects (1.36/lead), 34 outside-in defects (0.32/lead), 36 defects caused by the ICD can (0.34/lead), and 9 unspecified defects. Of the 143 inside-out insulation defects, 93 (65.0%) were distal to the proximal shocking coil and 33 (31%) had exposed conductor cables. The ETFE high voltage cable insulation was abraded in 22 of 43 (51.2%) leads reported. Clinical signs of failure included: noise/oversensing (45/105; 42.8%); impedance changes (23/105; 21.9%); high threshold or loss of capture (11/105; 10.4%); and other (26/105; 24.7%) including 7 externalized cables (6.6%). Inappropriate shocks affected 29 patients (27.6%), and one death was associated with a can abrasion and truncated high voltage shock. Conclusions: Explanted Riata and Riata ST leads were found to have multiple inside-out insulation defects which often involved the low voltage conductors. Thus lead noise and inappropriate shocks were common. High voltage cable insulation abrasion also occurred. These observations suggest that Riata leads may have more widespread damage than can be detected by fluoroscopic examination.

JAMA, 1999

Context Hypertrophic cardiomyopathy (HCM) has been regarded as a disease that causes substantial ... more Context Hypertrophic cardiomyopathy (HCM) has been regarded as a disease that causes substantial disability, with annual mortality rates of up to 6%, based largely on reports from tertiary referral centers. Objective To assess the clinical course of HCM in a patient cohort more closely resembling the true disease state. Design Retrospective cohort study. Setting A regional cohort from Minnesota and adjoining regions, free of referral center bias, studied at Minneapolis Heart Institute.

JACC: Cardiovascular Interventions, 2010

Objectives The objectives of this study were: 1) to delineate the temporal course of histopatholo... more Objectives The objectives of this study were: 1) to delineate the temporal course of histopathologic healing as the left atrial appendage (LAA) is obliterated by a mechanical device; and 2) to compare this process with other intravascular and intracardiac implanted technologies. Background Intracardiac device healing is incompletely understood. We thus studied the histopathology of device-based LAA obliteration. Methods Nine dog hearts were examined over time after LAA device placement and results were compared with human hearts with prior LAA obliteration using the same device. Results At 3 days in dogs, atrial surfaces were covered by fibrin, which sealed gaps between the LA wall and the device and filled the LA appendage cavity. At 45 days, endothelial cells covered the endocardial surface with underlying smooth muscle cells that sealed the device-LA interface. Regions with prior thrombus were replaced by endocardium surrounding the device membrane. Disorganized thrombus remained in the LAA body and at the periphery near the appendage walls. Mild inflammation was observed as thrombus resorbed. By 90 days, a complete endocardial lining covered the former LAA ostium. Organizing thrombus had become connective tissue, with no residual inflammation. The human necropsy hearts had similar findings. In these 4 hearts (139, 200, 480, and 852 days after implant), the ostial fabric membrane was covered with endocardium. The appendage surface contained organizing thrombus with minimal inflammation. Organizing fibrous tissue was inside the LAA cavity, prominent near the atrial wall. The LAA interior contained organizing thrombus. Conclusions This intracardiac device integration study delineated healing stages of early thrombus deposition, thrombus organization, inflammation and granulation tissue, final healing by connective tissue, and endocardialization without inflammation. These observations may yield insight into cellular healing processes in other cardiac devices.

Heart Rhythm, 2010

BACKGROUND The Medtronic Sprint Fidelis high-voltage implantable cardioverter-defibrillator (ICD)... more BACKGROUND The Medtronic Sprint Fidelis high-voltage implantable cardioverter-defibrillator (ICD) lead is prone to fracture. The majority of fractures involve the pace-sense (P/S) conductors and may result in multiple inappropriate shocks. The Medtronic lead integrity alert (LIA) algorithm was designed to improve early detection of transient P/S conductor fractures and to decrease the incidence and number of inappropriate shocks. OBJECTIVE The purpose of this prospective single-center study was to assess the effectiveness of the LIA algorithm for warning patients of an impending Sprint Fidelis P/S conductor fracture and for decreasing the incidence and number of inappropriate shocks. METHODS The study population included all patients who had Sprint Fidelis leads and Medtronic ICD pulse generators that were implanted and followed at the Minneapolis Heart Institute. Patients were evaluated in the clinic every 3 to 4 months or by remote monitoring using the Medtronic CareLink system. When the LIA algorithm was released in August 2008, the RAMware was downloaded to the pulse generator of all patients with the Sprint Fidelis lead. Patients and family members received educational materials and were given a demonstration of the audible alerts.

Europace, 2012

Riata ST Optim TM and Durata ICD leads have failed due to insulation abrasions. Optim TM did not ... more Riata ST Optim TM and Durata ICD leads have failed due to insulation abrasions. Optim TM did not prevent these abrasions, which developed ≤4 years after implant. Studies are needed to determine the incidence of these failures and their clinical implications.

Circulation: Cardiovascular Quality and Outcomes, 2012

Background— Postmarket medical device surveillance in the United States depends largely on volunt... more Background— Postmarket medical device surveillance in the United States depends largely on voluntary reporting of adverse events. Consequently, early safety signals may be missed, exposing patients to potentially hazardous products. The aim of this study was to assess the feasibility of using an automated safety surveillance tool to detect early signals that a marketed implantable cardiac device was underperforming. Methods and Results— For this purpose, we performed simulated prospective monthly full-cohort and propensity-matched comparative survival analyses on our 3-center database of Sprint Fidelis and Quattro Secure implantable cardioverter-defibrillator leads, using a commercially available automated surveillance tool that was preset to trigger an alert if the log rank probability value was <0.05. During the study, 84 of 1035 Fidelis (8.1%) and 23 of 1675 Quattro (1.4%) leads failed. The simulated full-cohort analysis triggered a sustained alert for Fidelis leads beginning ...

Angiology, 2013

The impact of peripheral artery disease (PAD) on survival in implantable cardioverter defibrillat... more The impact of peripheral artery disease (PAD) on survival in implantable cardioverter defibrillator (ICD) patients is poorly understood. Thus, we assessed the risk of PAD in our adult ICD patients with left ventricular dysfunction (ejection fraction [EF] ≤35%). Survival was estimated with Kaplan-Meier method and compared by the log-rank test; a Cox proportional hazards model assessed the effects of clinical variables on survival. Average age and EF of 1399 patients were 67.0 ± 12.1 years and 23.8% ± 7.2%, respectively. The ICD patients with PAD had significantly worse survival than those without (unadjusted P < .0001). The multivariate predictors of survival at implant were (hazard ratio, HR [95% confidence interval]) age (HR 1.05 [1.04-1.07] P < .0001), PAD (HR 2.07 [1.53-2.80] P < .0001), class III/IV heart failure (HR 1.36 [1.06-1.76] P = .016), creatinine 1.4-2.0 mg/dL (HR 1.36 [1.05-1.76] P = .019), and creatinine ≥2.0 mg/dL (HR 2.01 [1.42-2.85] P < .0001). The PAD ...

The American Journal of Cardiology, 2008

Two patients with hypertrophic cardiomyopathy are reported from the recent experience of the Hype... more Two patients with hypertrophic cardiomyopathy are reported from the recent experience of the Hypertrophic Cardiomyopathy Center of the Minneapolis Heart Institute Foundation, demonstrating limitations in the risk stratification algorithm currently used for this disease. One patient, an asymptomatic 21-year-old male college student, was prophylactically implanted with a cardioverter-defibrillator. This decision was based largely on the presence of apparent extensive myocardial fibrosis identified by contrast-enhanced cardiovascular magnetic resonance imaging, currently not considered a risk factor in this disease. Fifteen months later, ventricular fibrillation was interrupted by an appropriate defibrillator shock. The other patient, an asymptomatic 15-year-old male subject without any apparent highrisk markers, died suddenly at home. Necropsy examination of the heart identified scarring confined to portions of both left ventricular papillary muscles, possibly representing a substrate for ventricular tachyarrhythmias. In conclusion, these 2 cases demonstrate that present strategies for assessing high-risk status in hypertrophic cardiomyopathy are inadequate to identify all such patients. However, while the anecdotal nature of these observations cannot yet justify altering the general guidelines for implantation of defibrillators for the primary prevention of sudden death related to hypertrophic cardiomyopathy, 1 of our 2 cases suggests a future role for contrast-enhanced cardiovascular magnetic resonance in the risk stratification of this complex disease.

Journal of the American College of Cardiology, Mar 1, 2015

background: Women with STEMI are less likely to receive guideline recommended medications and rep... more background: Women with STEMI are less likely to receive guideline recommended medications and reperfusion therapy compared to men. They have longer times to treatment and higher mortality. Whether the higher mortality is related to treatment disparities or sexrelated biological differences is controversial. methods: Using a comprehensive prospective regional percutaneous coronary intervention (PCI) based STEMI system database with a standardized STEMI protocol, we evaluated demographic information, risk factors, treatment and clinical outcomes of STEMI patients stratified by sex. Results: From 3/03 to 1/13, 3,785 consecutive STEMI patients presented to the Minneapolis Heart Institute at Abbott Northwestern Hospital regional STEMI system including 1088 (28.8%) women. Women were older with higher rates of hypertension, diabetes and cardiogenic shock but lower rates of previous MI and revascularization (table). After age-adjustment, women had similar outcomes to men including revascularization, door-to-balloon times, and in-hospital mortality. Sex was not a significant predictor of in-hospital mortality in a multivariate model. conclusion: The previously reported disparities between men and women are not evident in a Regional PCI-based STEMI system with a standardized STEMI protocol. These results suggest that STEMI healthcare disparities and mortality in women can be improved using STEMI protocols and systems.