Association of pre-left ventricular assist device defibrillator shocks for ventricular arrhythmia with clinical outcomes after left ventricular assist device implantation.

Background: Implantable cardioverter-defibrillation (ICD) shocks after left ventricular assist device therapy (LVAD) are associated with adverse clinical outcomes. Little is known about the association of pre-LVAD ICD shocks on post-LVAD clinical outcomes and whether LVAD therapy affects the prevalence of ICD shocks. Objectives: The purpose of this study was to determine whether pre-LVAD ICD shocks are associated with adverse clinical outcomes post-LVAD and to compare the prevalence of ICD shocks before and after LVAD therapy. Methods: Patients 18 years or older with continuous-flow LVADs and ICDs were retrospectively identified within the University of Pittsburgh Medical Center system from 2006-2020. We analyzed the association between appropriate ICD shocks within 1 year pre-LVAD with a primary composite outcome of death, stroke, and pump thrombosis and secondary outcomes of post-LVAD ICD shocks and ICD shock hospitalizations. Results: Among 309 individuals, average age was 57 ± 12 years, 87% were male, 80% had ischemic cardiomyopathy, and 42% were bridge to transplantation. Seventy-one patients (23%) experienced pre-LVAD shocks, and 69 (22%) experienced post-LVAD shocks. The overall prevalence of shocks pre-LVAD and post-LVAD were not different. Pre-LVAD ICD shocks were not associated with the composite outcome. Pre-LVAD ICD shocks were found to predict post-LVAD shocks (hazard ratio [HR] 5.7; 95% confidence interval [CI] 3.42-9.48; P <.0001) and hospitalizations related to ICD shocks from ventricular arrhythmia (HR 10.34; 95% CI 4.1-25.7; P <.0001). Conclusion: Pre-LVAD ICD shocks predicted post-LVAD ICD shocks and hospitalizations but were not associated with the composite outcome of death, pump thrombosis, or stroke at 1 year. The prevalence of appropriate ICD shocks was similar before and after LVAD implantation in the entire cohort.

Cardiovascular Hospitalizations and Resource Use Following Atrial Fibrillation Ablation.

Background Over the next few years, atrial fibrillation (AF)-related morbidity and costs will increase significantly. Thus, it is prudent to examine the impact of AF treatment on health care resource use. This study examined the impact of AF ablation on hospitalization, length of stay, and resource use for patients undergoing AF ablation in a multihospital system. Methods and Results In an observational analysis, outcomes of total, cardiovascular, and AF hospitalizations, emergency department visits, and length of stay were compared for 3417 patients between 12 months before and 24 months following AF ablation. Use of electrical cardioversions and antiarrhythmic use were also compared 1 year before to 2 years after AF ablation. There were fewer total (0.7±1.3 versus 0.3±0.7; P<0.001), cardiovascular (0.7±1.2 versus 0.2±0.6; P<0.001), and AF (0.6±1.1 versus 0.1±0.3; P<0.001) hospitalizations and emergency department visits (0.8±2.1 versus 0.4±0.9; P<0.001) per patient-year for the 2 years following AF ablation compared with 1 year before. Average length of stay per patient-year (1.4±7.9 versus 3.6±5.3 days; P<0.0001), the percentage of patients on antiarrhythmic therapy (21.2% versus 58.5%; P<0.0001), and those undergoing electrical cardioversions (16.1% versus 28.1%; P<0.0001) were lower 2 years following AF ablation versus 1 year before. Conclusions We noted a decrease in total, cardiovascular, and AF hospitalizations and health care resource use during the 2-year period after index AF ablation, compared with the 1 year before. AF ablation may portend a decline in patient morbidity and health care costs.

Non-vitamin K oral anticoagulants versus warfarin for left atrial appendage thrombus resolution in nonvalvular atrial fibrillation or flutter.

BACKGROUND: Non-vitamin K oral anticoagulants (NOACs) have emerged as alternatives to vitamin K antagonists in select situations. For left atrial (LA) appendage thrombus in nonvalvular atrial fibrillation (AF) or flutter, guidelines recommend oral anticoagulation (OAC) for at least 3 weeks prior to reassessment. Data comparing NOACs to warfarin in this scenario are scarce. METHODS: A retrospective study identified subjects with nonvalvular AF or flutter who were: a) noted to have LA thrombus detected on transesophageal echocardiography (TEE), b) previously not receiving long-term OAC; and c) evaluated for resolution of LA thrombus by follow-up TEE between 3 weeks to less than 1 year of the initial TEE. RESULTS: The study included 45 subjects with mean age 63.2 years, 69% male, 78% white race/ethnicity, 42% paroxysmal, and mean CHA2 DS2 -VASc score 3.4 ± 1.7. All LA thrombi were confined to the appendage. OAC received included apixaban (3), dabigatran (13), rivaroxaban (6), and warfarin (23), The median follow-up time to repeat TEE was 67 (interquartile range, 49-96) days. LA appendage thrombus resolution rates were 76% for the entire cohort, 77% for NOACs, and 74% for warfarin. In univariable logistic regression analysis, LA appendage thrombus resolution was similar for NOACs when compared to warfarin (odds ratio, 1.20; 95% confidence interval, 0.31-4.69; P = .79). CONCLUSIONS: In patients nonvalvular AF or flutter who were OAC naïve at the time of diagnosis with LA appendage thrombus, complete resolution was similar between NOACs and warfarin.

Comparison of Long-Term Survival Following Sudden Cardiac Arrest in Men Versus Women.

Sudden cardiac death (SCA) is a major cause of mortality with estimates of 450,000 deaths annually in the United States. The incidence of SCA differs between the sexes. Data regarding survival of women compared with men after SCA are, however, conflicting. We, therefore, examined the long-term survival of women versus men after SCA. A total of 1,433 (41% women; 44% out-of-hospital) survivors of SCA at our institution between 2002 and 2012 were followed to the primary end point of death through February 20, 2017. Women in our cohort were older (p = 0.02), were less likely to be white (p = 0.01), or to have suffered an acute myocardial infarction at the time of SCA (p < 0.001). They also had significantly shorter PR (p < 0.001) and QRS (p < 0.001) durations on their surface electrocardiogram, were more likely to present with an initial ventricular rhythm other than ventricular tachycardia or ventricular fibrillation (29% vs 22%, p = 0.001) and less likely to receive an implantable cardioverter defibrillator (22% vs 31%, p < 0.001). Over a median follow-up of 3.6 years, 674 (45%) patients died (53% women vs 43% men, p < 0.001). After adjusting for unbalanced baseline covariates, the sex difference in survival disappeared (hazard ratio 1.05; 95% confidence interval 0.85 to 1.29, p = 0.66). In conclusion, our results demonstrate comparable long-term mortality after SCA for men and women. Differences in unadjusted mortality are mainly due to older age, different risk profiles at the time of index event, and differential treatment with implantable cardioverter defibrillator.

Sex-specific clinical outcomes after cardiac resynchronization therapy in left bundle branch block-associated idiopathic nonischemic cardiomyopathy: A NEOLITH II substudy.

BACKGROUND: Sex differences in clinical outcomes for left bundle branch block (LBBB)-associated idiopathic nonischemic cardiomyopathy (NICM) after cardiac resynchronization therapy (CRT) are not well described. METHODS: A retrospective cohort study at an academic medical center included subjects with LBBB-associated idiopathic NICM who received CRT. Cox regression analyses estimated the hazard ratios (HRs) between sex and clinical outcomes. RESULTS: In 123 total subjects (mean age 62 years, mean initial left ventricular ejection fraction 22.8%, 76% New York Heart Association class III, and 98% CRT-defibrillators), 55 (45%) were men and 68 (55%) were women. The median follow-up time after CRT was 72.4 months. Similar risk for adverse clinical events (heart failure hospitalization, appropriate implantable cardioverter-defibrillator shock, appropriate antitachycardia pacing therapy, ventricular assist device implantation, heart transplantation, and death) was observed between men and women (HR, 1.20; 95% confidence interval [CI] 0.57-2.51; p = 0.63). This persisted in multivariable analyses. Men and women had similar risk for all-cause mortality in univariable analysis, but men had higher risk in the final multivariable model that adjusted for age at diagnosis, QRS duration, and left ventricular end-diastolic dimension index (HR, 4.55; 95% CI, 1.26-16.39; p = 0.02). The estimated 5-year mortality was 9.5% for men and 6.9% for women. CONCLUSIONS: In LBBB-associated idiopathic NICM, men have higher risk for all-cause mortality after CRT when compared to women.

Myocardial recovery after cardiac resynchronization therapy in left bundle branch block-associated idiopathic nonischemic cardiomyopathy: A NEOLITH II substudy.

BACKGROUND: Baseline predictors of myocardial recovery after cardiac resynchronization therapy (CRT) in left bundle branch block (LBBB)-associated idiopathic nonischemic cardiomyopathy (NICM) are unknown. METHODS: A retrospective study included subjects with idiopathic NICM, left ventricular ejection fraction (LVEF) ≤35%, and LBBB. Myocardial recovery was defined as post-CRT LVEF ≥50%. Logistic regression analyses described associations between baseline characteristics and myocardial recovery. Cox regression analyses estimated the hazard ratio (HR) between myocardial recovery status and adverse clinical events. RESULTS: In 105 subjects (mean age 61 years, 44% male, mean initial LVEF 22.6% ± 6.6%, 81% New York Heart Association class III, and 98% CRT-defibrillators), myocardial recovery after CRT was observed in 56 (54%) subjects. Hypertension, heart rate, and serum blood urea nitrogen (BUN) had negative associations with myocardial recovery in univariable analyses. These associations persisted in multivariable analysis: hypertension (odds ratio (OR), 0.40; 95% confidence interval (CI), 0.17-0.95; p = 0.04), heart rate (OR per 10 bpm, 0.69; 95% CI, 0.48-0.997; p = 0.048), and serum BUN (OR per 1 mg/dl, 0.94; 95% CI, 0.88-0.99; p = 0.04). Subjects with post-CRT LVEF ≥50%, when compared to <50%, had lower risk for adverse clinical events (heart failure hospitalization, appropriate implantable cardioverter-defibrillator shock, appropriate anti-tachycardia pacing therapy, ventricular assist device implantation, heart transplantation, and death) over a median follow-up of 75.9 months (HR, 0.38; 95% CI, 0.16-0.88; p = 0.02). CONCLUSION: In LBBB-associated idiopathic NICM, myocardial recovery after CRT was associated with absence of hypertension, lower heart rate, and lower serum BUN. Those with myocardial recovery had fewer adverse clinical events.

Oral anticoagulation and left atrial thrombi resolution in nonrheumatic atrial fibrillation or flutter: A systematic review and meta-analysis.

BACKGROUND: Oral anticoagulation (OAC) is prescribed for left atrial thrombi (LAT) in nonrheumatic atrial fibrillation (AF) and/or atrial flutter (AFL). The study objective was to review the existing evidence regarding LAT resolution in nonrheumatic AF and/or AFL with OAC agents. METHODS: Data sources included PubMed, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) between January 1, 1991 and February 10, 2017. English-language studies that assessed LAT resolution with OAC agents in subjects with nonrheumatic AF and/or AFL, by serial transesophageal echocardiography, and with follow-up times ≥ 3 weeks and < 1 year, were selected. Study quality was assessed using recommendations adapted from the Agency for Healthcare Research and Quality. Pooled LAT resolution rates were evaluated for vitamin K antagonist (VKA) studies and low risk of bias warfarin studies. RESULTS: The pooled LAT resolution rate of 619 subjects from 16 VKA studies was 63.7% (95% confidence interval [CI], 53.3%-72.9%). The pooled LAT resolution rate of 94 subjects from four studies that specified warfarin use, exclusion of prior long-term therapeutic OAC, and target international normalized ratio (INR) ≥ 2.0 and/or average achieved INR ≥ 2.0 was 79.3% (95% CI, 69.8%-86.4%). Two studies in direct-acting oral anticoagulants (DOACs) reported LAT resolution rates of 89.5% (17 of 19) for dabigatran and 41.5% (22 of 53) for rivaroxaban. CONCLUSIONS: Warfarin is the most studied initial OAC agent for treating LAT in nonrheumatic AF and/or AFL with a resolution rate of nearly 80%. Further studies in DOACs are warranted.

New-onset left bundle branch block-associated idiopathic nonischemic cardiomyopathy and time from diagnosis to cardiac resynchronization therapy: The NEOLITH II study.

BACKGROUND: The optimal timing for cardiac resynchronization therapy (CRT) after diagnosis of new-onset left bundle branch block (LBBB)-associated idiopathic nonischemic cardiomyopathy (NICM) and treatment with guideline-directed medical therapy (GDMT) is unknown. The purpose of this study was to describe relationships between time from diagnosis to CRT and outcomes in new-onset LBBB-associated idiopathic NICM with left ventricular ejection fraction (LVEF) ≤35%. METHODS: A retrospective cohort study examined associations between time from diagnosis to CRT (≤9 months vs >9 months) and clinical and echocardiographic outcomes. RESULTS: In 123 subjects with LBBB-associated idiopathic NICM, time from diagnosis to CRT was ≤9 months in 60 (49%) subjects and 9 months in 63 (51%) subjects. Clinical outcomes were similar for those implanted ≤9 months versus >9 months for adverse clinical events (hazard ratio [HR], 0.85; 95% confidence interval [CI], 0.41-1.78; P = 0.67) and all-cause mortality (HR, 0.57; 95% CI, 0.19-1.70; P = 0.31). Multivariable analyses demonstrated similar results. In 105 subjects with post-CRT echocardiograms, LVEF improvement to >35% was more likely in those implanted ≤9 months when compared to >9 months (odds ratio [OR], 3.53; 95% CI, 1.32-9.46; P = 0.01). This association persisted in the final multivariable model adjusted for age at diagnosis, sex, QRS duration, post-GDMT LVEF, and time from CRT to post-CRT echocardiogram (OR, 5.10; 95% CI, 1.71-15.22; P = 0.004). CONCLUSION: In LBBB-associated idiopathic NICM, earlier CRT implantation was associated with more favorable cardiac remodeling. Delaying CRT may miss a critical period to halt and reverse progressive myocardial damage.

Predictors and implications of early left ventricular ejection fraction improvement in new-onset idiopathic nonischemic cardiomyopathy with narrow QRS complex: A NEOLITH substudy.

BACKGROUND: Predictors and implications of early left ventricular ejection fraction (LVEF) improvement with guideline-directed medical therapy (GDMT) in new-onset idiopathic nonischemic cardiomyopathy (NICM) with narrow QRS complex are not well described. The objectives were to describe predictors of LVEF improvement after 3 months on GDMT and adverse cardiac events based on post-GDMT LVEF status (≤35% vs. >35%). METHODS: A retrospective cohort study was performed in subjects with new-onset NICM, LVEF ≤35%, and narrow QRS complex. Associations for baseline variables with post-GDMT LVEF improvement and absolute change in LVEF (∆LVEFGDMT ) were assessed. Cox proportional hazards models assessed associations for post-GDMT LVEF status with adverse cardiac events. RESULTS: In 70 subjects, 31 (44%) had post-GDMT LVEF ≤35% after a median follow-up time of 97.5 days (interquartile range, 84-121 days). In final multivariable models, severely dilated left ventricular end-diastolic diameter (LVEDD), compared with normal LVEDD, strongly predicted post-GDMT LVEF ≤35% (odds ratio, 7.77; 95% confidence interval [CI], 1.39-43.49; p = .02) and ∆LVEFGDMT (ß = -15.709; standard error = 4.622; p = .001). Subjects with post-GDMT LVEF ≤35% were more likely to have adverse cardiac events over a median follow-up time of 970.5 days (unadjusted hazard ratio, 2.15; 95% CI, 0.93-4.96; p = .07). In the post-GDMT LVEF ≤35% group, 9 of 26 subjects (35%) had long-term LVEF > 35%. CONCLUSION: In new-onset NICM with narrow QRS complex, nondilated LVEDD predicted early LVEF improvement. Those with post-GDMT LVEF ≤35% had higher risk of adverse cardiac events, but a substantial proportion demonstrated continued long-term LVEF improvement.

Characteristics and Outcomes of Concurrently Diagnosed New Rapid Atrial Fibrillation or Flutter and New Reduced Ejection Fraction.

BACKGROUND: Characteristics and outcomes of concurrently diagnosed new rapid atrial fibrillation (AF) or atrial flutter (AFL) and new heart failure with reduced left ventricular ejection fraction (LVEF) are not well described. METHODS: A retrospective cohort study of subjects referred for expedited transesophageal echocardiography-guided rhythm-control strategies for concurrent new rapid AF/AFL and new LVEF ≤ 40% diagnosed during the same admission was analyzed. RESULTS: Twenty-five subjects (median age 57 years; 96% male; 96% Caucasian; median CHA2 DS2 -VASc = 2) presented with new AF (n = 18) or AFL (n = 7) with rapid ventricular rate (median 135 beats/min) and new reduced LVEF (median 27%; range, 10-37.5%). Seven (28%) subjects had left atrial appendage thrombi (LAAT) and five (20%) subjects had heavy or binge alcohol use. Baseline characteristics were similar between those with and without LAAT. Thirteen subjects with AF and without LAAT underwent direct-current cardioversion (DCCV) and 10 (77%) had AF recurrence within 90 days. Improvement of long-term LVEF to >40% was comparable for subjects with and without initial LAAT (83% vs 94%; P = 0.46). Three of four subjects who received primary prophylaxis implantable cardioverter-defibrillators improved their LVEF to >35% after sinus rhythm maintenance. The median long-term follow-up time was 3.0 years. CONCLUSIONS: Subjects with concurrently diagnosed new rapid AF/AFL and new reduced LVEF are characterized by a high prevalence of LAAT and significant alcohol use. AF subjects without initial LAAT who underwent DCCV had a high 90-day AF recurrence rate. The presence of LAAT did not have a prognosticative effect on eventual LVEF improvement, which was observed in almost all subjects.

Leadless pacemakers: A new era in cardiac pacing.

Cardiac pacemakers are a critical management option for patients with rhythm disorders. Current efforts to develop leadless pacemakers have two primary goals: to reduce lead-associated post-procedural morbidity and to avoid the surgical scar associated with placement. After extensive studies on animal models and technological advancements, these devices are currently under investigation for human use. Herein, we review the evidence from animal studies and the technological advancements that have ushered in the era of use in humans. We also discuss different leadless pacemakers currently under investigation, along with limitations and future developments of this innovative concept.

New-onset left bundle branch block-associated idiopathic nonischemic cardiomyopathy and left ventricular ejection fraction response to guideline-directed therapies: The NEOLITH study.

BACKGROUND: Left ventricular ejection fraction (LVEF) response to guideline-directed medical therapy (GDMT) and to early cardiac resynchronization therapy (CRT) in new-onset idiopathic nonischemic cardiomyopathy (NICM) and left bundle branch block (LBBB) is not well described. CRT is recommended if LVEF remains ≤35% after at least 3 months of GDMT. OBJECTIVE: The purpose of this study was to describe LVEF response to GDMT at 3 months and to early CRT in new-onset LBBB-associated idiopathic NICM. METHODS: A retrospective cohort study was performed in subjects with new-onset idiopathic NICM, LVEF ≤35%, and LBBB or narrow (<120 ms) QRS complex morphology. LVEF response between groups was evaluated with log-binomial and linear regression. LVEF response within groups was evaluated using the paired Student t test. RESULTS: In 102 subjects (70 with narrow QRS complex and 32 with LBBB), post-GDMT LVEF was >35% in 39 narrow QRS complex subjects (56%) and 2 LBBB subjects (6%) (P < .0001). The absolute difference between post-GDMT LVEF and initial LVEF was greater in the narrow QRS complex group (16.1% ± 14.6% vs. 3.3% ± 10.7%; P < .0001). Narrow QRS complex, referenced to LBBB, was significantly associated with post-GDMT LVEF >35% (relative risk 10.30; 95% confidence interval 2.63-40.27; P = .0008) and absolute difference between post-GDMT LVEF and initial LVEF (ß = 16.296; standard error = 2.977; P < .0001) in final multivariable analyses. CRT super-response, defined as post-CRT LVEF ≥50%, was observed in 8 of LBBB subjects (35%) who received CRT. CONCLUSION: GDMT did not significantly improve LVEF in new-onset LBBB-associated idiopathic NICM at 3 months. Most remained candidates for CRT, and a high percentage were super-responders. Optimal timing for CRT implantation requires further investigation.

Utility of the Wearable Cardioverter-Defibrillator in Patients With Newly Diagnosed Cardiomyopathy: A Decade-Long Single-Center Experience.

BACKGROUND: The wearable cardioverter-defibrillator (WCD) has emerged as a means of protecting patients with newly diagnosed nonischemic cardiomyopathy (NICM) or ischemic cardiomyopathy (ICM) against sudden cardiac death while awaiting re-evaluation of cardiac function. OBJECTIVES: This study sought to characterize the risk of appropriate WCD therapy in newly diagnosed NICM and ICM patients according to cardiomyopathy etiology in an independent study. METHODS: Medical records of all patients prescribed a WCD between June 2004 and May 2015 at our institution (n = 639) were analyzed, focusing on 254 patients with newly diagnosed NICM and 271 patients with newly diagnosed ICM. Patients with a prior implantable cardioverter-defibrillator or sustained ventricular arrhythmias were excluded (n = 114). The primary endpoint was appropriate WCD therapy. RESULTS: Median WCD wear time was 61 days (interquartile range [IQR]: 25 to 102 days) per patient and 22 h/day (IQR: 17 to 23 h/day). During 56.7 patient-years, 0 NICM patients received an appropriate WCD shock, whereas 3 (1.2%) received an inappropriate shock. During 46.7 patient-years, 6 (2.2%) ICM patients received an appropriate shock; 5 survived the episode, and 4 survived to hospital discharge. All 6 patients with an appropriate shock were male with QRS duration >120 ms. Two (0.7%) ICM patients received an inappropriate shock. CONCLUSIONS: In this independent, retrospective study, the risk of appropriate WCD therapies in patients with newly diagnosed NICM was minimal. Routine use of the WCD in this population should be prospectively evaluated. The risk of appropriate therapies in newly diagnosed ICM was comparable to that observed in prior observational studies.