Search

Abstract Background The value of Single Photon Emission Computed Tomography stress myocardial perfusion imaging (SPECT-MPI) for detecting graft disease after coronary artery bypass surgery (CABG) has not been studied prospectively in an unselected cohort. Methods Radial Artery Versus Saphenous Vein Graft Study is a Veterans Affairs Cooperative Study to determine graft patency rates after CABG surgery. Seventy-nine participants agreed to SPECT-MPI within 24 hours of their coronary angiogram, one-year after CABG. The choice of the stress protocol was made at the discretion of the nuclear radiologist and was either a symptom-limited exercise test (n = 68) or an adenosine infusion (n = 11). The SPECT-MPI results were interpreted independent of the angiographic results and estimates of sensitivity, specificity and accuracy were based on the prediction of a graft stenosis of ≥70% on coronary angiogram. Results A significant stenosis was present in 38 (48%) of 79 patients and 56 (22%) of 251 grafts. In those stress tests with an optimal exercise heart rate response (>80% maximum predicted heart rate) (n = 26) sensitivity, specificity and accuracy of SPECT-MPI for predicting the graft stenosis was 77%, 69% and 73% respectively. With adenosine (n = 11) it was 75%, 57% and 64%, respectively. Among participants with a suboptimal exercise heart rate response, the sensitivity of SPECT-MPI for predicting a graft stenosis was Conclusions Under optimal stress conditions, SPECT-MPI has a good sensitivity and accuracy for detecting graft disease in an unselected patient population 1 year post-CABG.

Abstract Background Mortality and complications after percutaneous coronary intervention is higher when performed after regular duty hours due to challenging patient characteristics, inferior processes of care and limited resources. Since these challenges are also encountered during coronary artery bypass graft (CABG) surgery that is performed after regular work hours, we assessed whether hour and day of procedure influenced mortality after CABG. Methods We studied 4,714 consecutive patients who underwent CABG at the Minneapolis Veterans Administration (VA) Medical Center between 1987 and 2009. We compared postoperative (30-day) mortality rates in relation to hour and day in which the operation was performed. Results Operations performed on weekends and after 4 PM had higher risk patients (p < 0.0001) and were more likely to be emergent (p < 0.0001), require intra-aortic balloon pump support (p < 0.0001) and result in postoperative complications (p < 0.0001) compared to those at regular work hours. Mortality was significantly higher when CABG was performed on weekends compared to weekdays (9.4% versus 2.5%; odds ratio (OR) 4.1, 95% confidence interval (CI) 1.6 to 10.4, p = 0.003), and after 4 PM compared to between 7 AM-4 PM (6.2% versus 2.2%; OR 2.9, 95% CI 1 to 8, p = 0.049). In multivariable analysis, when adjusted for the urgency of the operation and the VA estimated mortality risk score, these associations were no longer statistically significant. Conclusions Mortality after CABG is higher when surgery is performed on the weekends and after 4 PM. These variations in mortality were related to higher patient risk, and urgency of the operation rather than external factors.

Abstract Background Previous studies on the effects of Statins in preventing atrial fibrillation (AF) after cardiac surgery have shown conflicting results. Whether statins prevent AF in patients treated with postoperative beta blockers and whether the statin-effect is dose related are unknown. Methods We retrospectively studied 1936 consecutive patients who underwent coronary artery bypass graft (CABG) (n = 1493) or valve surgery (n = 443) at the Minneapolis Veterans Affairs Medical Center. All patients were in sinus rhythm before the surgery. Postoperative beta blockers were administered routinely (92% within 24 hours postoperatively). Results Mean age was 66+10 years and 68% of the patients were taking Statins. Postoperative AF occurred in 588 (30%) patients and led to longer length of stay in the intensive care unit versus those without AF (5.1+7.6 days versus 2.5+2.3 days, p < 0.0001). Patients with a past history of AF had a 5 times higher risk of postoperative AF (odds ratio 5.1; 95% confidence interval 3.4 to 7.7; p < 0.0001). AF occurred in 31% of patients taking statins versus 29% of the others (p = 0.49). In multivariable analysis, statins were not associated with AF (odds ratio (OR) 0.93, 95% confidence interval (CI) 0.7 to 1.2; p = 0.59). However, in a subgroup analysis, the patients treated with Simvastatin >20 mg daily had a 36% reduction in the risk of postoperative AF (OR 0.64, 95% CI 0.43 to 0.6; p = 0.03) in comparison to those taking lower dosages. Conclusion Among cardiac surgery patients treated with postoperative beta blockers Statin treatment reduces the incidence of postoperative AF when used at higher dosages

Background: There is conflicting evidence on the efficacy of primary prevention implantable cardioverter-defibrillator (ICD) implantation in the elderly., Objective: The purpose of this study was to determine the efficacy and safety of ICD implantation in patients 70 years and older., Methods: Patients (n = 167) aged 70 years or older and eligible for ICD implantation were randomly assigned (1:1) to receive either optimal medical therapy (OMT) (n = 85) or OMT plus ICD (n = 82)., Results: Of the 167 participants (mean age 76.4 years; 165 men), 144 completed the study protocol according to their assigned treatment. Average participant follow-up was 31.5 months. Mortality was similar between the 2 groups: 27 deaths in OMT vs 26 death in ICD (unadjusted hazard ratio 0.92; 95% confidence interval 0.53-1.57), but there was a trend favoring the ICD over the first 36 months of follow-up. Rates of sudden death (7 vs 5; P = .81) and all-cause hospitalization (2.65 events per participant in OMT vs 3.09 in ICD; P = .31) were not statistically significantly different. Eleven participants randomized to ICD received appropriate therapy. Five participants received an inappropriate therapy that included at least 1 ICD shock., Conclusion: The study did not recruit to target sample size, and accumulated data did not show benefit of ICD therapy in patients 70 years or older. Future studies similar in design might be feasible but will need to contend with patient treatment preference given the large number of patients who do not want an ICD implanted. Further research is needed to determine whether the ICD is effective in prolonging life among elderly device candidates.

Atrial fibrillation/flutter (AF) is a major public health problem and is associated with stroke, heart failure, dementia, and death. It is estimated that 20%-30% of Americans will develop AF at some point in their life. Current medications to prevent AF have limited efficacy and significant adverse effects. Newer and safer therapies to prevent AF are needed. Ventricular arrhythmias are less prevalent than AF but may have significant consequences including sudden cardiac death. Metformin is the most prescribed, first-line medication for treatment of diabetes mellitus (DM). It decreases hepatic glucose production but also reduces inflammation and oxidative stress. Experimental studies have shown that metformin improves metabolic, electrical, and histologic risk factors associated with AF and ventricular arrhythmias. Furthermore, in large clinical observational studies, metformin has been associated with a reduced risk of AF in people with DM. These data suggest that metformin may have antiarrhythmic properties and may be a candidate to be repurposed as a medication to prevent cardiac arrhythmias. In this article, we review the clinical observational and experimental evidence for the association between metformin and cardiac arrhythmias. We also discuss the potential antiarrhythmic mechanisms underlying this association. Repurposing a well-tolerated, safe, and inexpensive medication to prevent cardiac arrhythmias has significant positive public health implications.

Background: Sudden cardiac death (SCD) is a significant global public health problem accounting for 15% to 20% of all deaths. A great majority of SCD is associated with coronary heart disease, which may first be detected at autopsy. The ankle-brachial index (ABI) is a simple, noninvasive measure of subclinical atherosclerosis. The purpose of this study was to examine the relationship between ABI and SCD in a middle-aged biracial general population., Methods and Results: Participants of the ARIC (Atherosclerosis Risk in Communities) study with an ABI measurement between 1987 and 1989 were included. ABI was categorized as low (≤0.90), borderline (0.90-1.00), normal (1.00-1.40), and noncompressible (>1.40). SCD was defined as a sudden pulseless condition presumed to be caused by a ventricular tachyarrhythmia in a previously stable individual and was adjudicated by a committee of cardiac electrophysiologists, cardiologists, and internists. Cox proportional hazards models were used to evaluate the associations between baseline ABI and incident SCD. Of the 15 081 participants followed for a median of 23.5 years, 556 (3.7%) developed SCD (1.96 cases per 1000 person-years). Low and borderline ABIs were associated with an increased risk of SCD (demographically adjusted hazard ratios [HRs], 2.27 [95% CI, 1.64-3.14] and 1.52 [95% CI, 1.17-1.96], respectively) compared with normal ABI. The association between low ABI and SCD remained significant after adjustment for traditional cardiovascular risk factors (HR, 1.63 [95% CI, 1.15-2.32])., Conclusions: Low ABI is independently associated with an increased risk of SCD in a middle-aged biracial general population. ABI could be incorporated into future SCD risk prediction models.

Introduction: QT prolongation is a risk factor for life-threatening arrhythmias and sudden cardiac death. In large cohorts, QT interval was associated with all-cause mortality, but these analyses may contain residual confounding. Whether the QT interval provides prognostic information above and beyond a validated mortality risk score is unknown. We hypothesized that QT interval on ECG will independently predict mortality after adjustment for the Care Assessment Needs (CAN) score, which was validated to predict mortality nationwide at the Veterans Administration (VA) (c-index 0.86)., Methods: Outpatients with an ECG at the Minneapolis VA from 2012 to 2016 were included in this retrospective cohort study. ECGs with ventricular rate < 50 or > 100 beats/min and those with QRS > 120 ms were excluded. QT intervals were corrected (QTc) using the Bazett's formula. CAN score, calculated within 1-week of the ECG, was obtained from the VA Corporate Data Warehouse., Results: Of the 31,201 patients, 427 (1.4%) had QTc ≥ 500 ms, 1799 (5.8%) had QTc 470-500 ms and 28,975 (92.9%) had QTc < 470 ms. Compared to those with QTc < 470 ms, CAN-adjusted odds ratios (OR) for 1-year mortality (1.76 for QTc 470-500 and 2.70 for QTc > 500 ms; p < 0.0001 for both) and for 5-year mortality (1.75 for QTc 470-500 and 2.48 for QTc > 500 ms; p < 0.0001 for both) were significantly higher in those with longer QTc. C-index for CAN score and QTc predicting 1-year mortality was 0.837., Conclusions: QT prolongation predicts all-cause mortality independently of a validated mortality risk prediction score., Competing Interests: Declaration of Competing Interest No potential conflict of interest relevant to this article was reported., (Published by Elsevier Inc.)

Introduction: Cardiovascular disease (CVD) remains the leading cause of death globally, including the Middle East and North Africa (MENA) region. However, limited research has been conducted on the burden of CVD in this region. Our study aims to investigate the burden of CVD and related risk factors in the MENA., Methods: We used data from the Global Burden of Disease (GBD) 2019 to examine CVD prevalence in 21 MENA countries. Prevalence and mortality were analyzed using Bayesian regression tools, demographic methods, and mortality-to-incidence ratios. Disability-adjusted life years (DALYs) were calculated, and risk factors were evaluated under the GBD's comparative risk assessment framework., Results: Between 1990 and 2019, CVD raw accounts in the MENA increased by 140.9%, while age standardized prevalence slightly decreased (-1.3%). CVD raw mortality counts rose by 78.3%, but age standardized death rates fell by 28%. Ischemic heart disease remained the most prevalent condition, with higher rates in men, while women had higher rates of CVA. Age standardized DALYs decreased by 32.54%. DALY rates varied across countries and were consistently higher in males. Leading risk factors included hypertension, high LDL-C, dietary risks, and elevated BMI.  The countries with the three highest DALYs in 2019 were Afghanistan, Egypt, and Yemen., Conclusions: While strides have been made in lessening the CVD burden in the MENA region, the toll on mortality and morbidity, particularly from ischemic heart disease, remains significant. Country-specific variations call for tailored interventions addressing socio-economic factors, healthcare infrastructure, and political stability., Competing Interests: Declaration of Competing Interest The authors do not have any conflicts of interest to disclose. All authors have approved this manuscript and this submission., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Balloon Tipped Temporary Pacemakers (BTTP) are the most used temporary pacemakers; however, they are associated with a risk of dislodgement and thromboembolism. Recently, Temporary Permanent Pacemakers (TPPM) have been increasingly used. Evidence of outcomes with TPPM compared to BTTP remains scarce., Methods: Retrospective, chart review study evaluating all patients who underwent temporary pacemaker placement between 2014 and 2022 (N = 126) in the cardiac catheterization laboratory (CCL) at a level 1 trauma center. Primary outcome of this study is to evaluate the safety profile of TPPM versus BTTP. Secondary objectives include patient ambulation and healthcare utilization in patients with temporary pacemakers., Results: Both groups had similar baseline characteristics distribution including gender, race, and age at temporary pacemaker insertion (p > .05). Subclavian vein was the most common site of access for the TPPM cohort (89.0%) versus the femoral vein in the BTTP group (65.1%). Ambulation was only possible in the TPPM group (55.6%, p < .001). Lead dislodgement, venous thromboembolism, local hematoma, and access site infections were less frequently encountered in the TPPM group (OR = 0.23 [95% CI (0.10-0.67), p < .001]). Within the subgroup of patients with TPPM, 36.6% of the patients were monitored outside the ICU setting. There was no significant difference in the pacemaker-related adverse events among patients with TPPM based on their in-hospital setting., Conclusion: TPPM is associated with a more favorable safety profile compared to BTTP. They are also associated with earlier patient ambulation and reduced healthcare utilization., (© 2024 Wiley Periodicals LLC.)

Rationale: The autonomic nervous system extensively innervates the lungs, but its role in chronic obstructive pulmonary disease (COPD) outcomes has not been well studied. Objective: We assessed relationships between cardiovascular autonomic nervous system measures (heart rate variability [HRV] and orthostatic hypotension [OH]) and incident COPD hospitalization in the multicenter ARIC (Atherosclerosis Risk In Communities) study. Methods: We used Cox proportional hazards regression models to estimate hazard ratios and 95% confidence intervals between baseline (1987-1989) autonomic function measures (HRV measures from 2-minute electrocardiograms and OH variables) and incident COPD hospitalizations through 2019. Adjusted analyses included demographic data, smoking status, lung function, comorbidities, and physical activity. We also performed analyses stratified by baseline airflow obstruction. Results: Of the 11,625 participants, (mean age, 53.8 yr), 56.5% were female and 26.3% identified as Black. Baseline mean percentage predicted forced expiratory volume in 1 second was 94 ± 17% (standard deviation), and 2,599 participants (22.4%) had airflow obstruction. During a median follow-up time of 26.9 years, there were 2,406 incident COPD hospitalizations. Higher HRV (i.e., better autonomic function) was associated with a lower risk of incident COPD hospitalization. Markers of worse autonomic function (OH and greater orthostatic changes in systolic and diastolic blood pressure) were associated with a higher risk of incident COPD hospitalization (hazard ratio for the presence of OH, 1.5; 95% confidence interval, 1.25-1.92). In stratified analyses, results were more robust in participants without airflow obstruction at baseline. Conclusions: In this large multicenter prospective community cohort, better cardiovascular autonomic function at baseline was associated with a lower risk of subsequent hospitalization for COPD, particularly among participants without evidence of lung disease at baseline.

Background: Atrial fibrillation (AF) guidelines recommend amiodarone as the preferred antiarrhythmic medication (AAM) in patients with left ventricular hypertrophy (LVH), due to potential pro-arrhythmic risk with other AAM. However, there are limited data to support this assertion., Methods: We retrospectively analyzed the records of 8204 patients who were prescribed AAM for AF and had transthoracic echocardiogram (TTE) at the multicenter, VA Midwest Health Care Network from 2000 to 2021. We excluded patients without LVH (septal or posterior wall dimension ≤1.4 cm). The primary outcome variable was all-cause mortality during antiarrhythmic therapy or within 6 months after stopping it. Propensity-stratified analyses were performed between amiodarone versus non-amiodarone (Vaughan-Williams Class I and III) AAM., Results: A total of 1277 patients with LVH (mean age 70.2 ± 9.5 years) were included in the analysis. Of these, 774 (60.6%) were prescribed amiodarone. Baseline characteristics of the two comparison groups were similar after propensity adjustment. After a median 1.40 years of follow-up, 203 (15.9%) patients died. Incidence rates per 100 patient-year follow-up was 9.02 (7.58-10.66) for amiodarone and 4.98 (3.91-62.56) for non-amiodarone. In propensity-stratified analysis, amiodarone use was associated with 1.58 times higher risk of mortality (95% CI 1.03-2.44; p = .038). Sub-group analysis in 336 (26.3%) patients with severe LVH showed no difference in mortality (HR 1.41, 95% CI 0.82-2.43, p = .21)., Conclusion: Among patients with AF and LVH, amiodarone was associated with a significantly higher mortality risk than other AAM., (© 2023 Wiley Periodicals LLC.)

Purpose: Obstructive sleep apnea syndrome (OSAS) is an important, modifiable risk factor in the pathophysiology of arrhythmias including atrial fibrillation (AF). The purpose of the study was to evaluate cardiac electrophysiologists' (EPs) perception of OSAS., Methods: We designed a 27-item online Likert scale-based survey instrument entailing several domains: (1) relevance of OSAS in EP practice, (2) OSAS screening and diagnosis, (3) perception on treatments for OSAS, (4) opinion on the OSAS care model. The survey was distributed to 89 academic EP programs in the USA and Canada. While the survey instrument questions refer to the term sleep apnea (SA), our discussion of the diagnosis, management, and research on the sleep disorder is more accurately described with the term OSAS., Results: A total of 105 cardiac electrophysiologists from 49 institutions responded over a 9-month period. The majority of respondents agreed that sleep apnea (SA) is a major concern in their practice (94%). However, 42% reported insufficient education on SA during training. Many (58%) agreed that they would be comfortable managing SA themselves with proper training and education and 66% agreed cardiac electrophysiologists should become more involved in management. Half of EPs (53%) were not satisfied with the sleep specialist referral process. Additionally, a majority (86%) agreed that trained advanced practice providers should be able to assess and manage SA. Time constraints, lack of knowledge, and the referral process are identified as major barriers to EPs becoming more involved in SA care., Conclusions: We found that OSAS is widely recognized as a major concern for EP. However, incorporation of OSAS care in training and routine practice lags. Barriers to increased involvement include time constraints and education. This study can serve as an impetus for innovation in the cardiology OSAS care model., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Background: Nearly 1/3rd of patients undergoing coronary artery bypass graft surgery (CABG) have left ventricular systolic dysfunction. However, the extent, direction and implications of perioperative changes in left ventricular ejection fraction (LVEF) have not been well characterized in these patients., Methods: We studied the changes in LVEF among 549 patients with left ventricular systolic dysfunction (LVEF &lt;50%) who underwent CABG as part of the Surgical Treatment for Ischemic Heart Failure (STICH) trial. Patients had pre- and post-CABG (4 month) LVEF assessments using identical cardiac imaging modality, interpreted at a core laboratory. An absolute change of &gt;10% in LVEF was considered clinically significant., Results: Of the 549 patients (mean age 61.4±9.55 years, and 72 [13.1%] women), 145 (26.4%) had a &gt;10% improvement in LVEF, 369 (67.2%) had no change and 35 (6.4%) had &gt;10% worsening of LVEF following CABG. Patients with lower preoperative LVEF were more likely to experience an improvement after CABG (odds ratio 1.36; 95% CI 1.21-1.53; per 5% lower preoperative LVEF; p &lt;0.001). Notably, incidence of postoperative improvement in LVEF was not influenced by presence, nor absence, of myocardial viability (25.5% vs. 28.3% respectively, p = 0.67). After adjusting for age, sex, baseline LVEF, and NYHA Class, a &gt;10% improvement in LVEF after CABG was associated with a 57% lower risk of all-cause mortality (HR: 0.43, 95% CI: 0.26-0.71)., Conclusions: Among patients with ischemic cardiomyopathy undergoing CABG, 26.4% had &gt;10% improvement in LVEF. An improvement in LVEF was more likely in patients with lower preoperative LVEF and was associated with improved long-term survival., Competing Interests: The authors have declared that no competing interests exist., (Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.)

Background: In ambulatory patients with heart failure (HF) with preserved ejection fraction (HFpEF), QRS prolongation (QRS > 120 msec) and left bundle branch block (LBBB) each carry an increased risk of cardiovascular mortality and/or HF hospitalization. Less is known about implications of conduction abnormalities following an acute HF hospitalization for HFpEF., Methods and Results: A retrospective cohort of 1454 patients discharged from after a HF hospitalization between 2015 and 2019 with ejection fraction (EF) ≥ 45% were identified (age 75.1 ± 10.8 years, EF 58.5% ± 10.2%). All patients' electrocardiograms were classified by QRS duration (prolonged - 545 [37.5%] vs. normal [QRS ≤ 120 msec] 909 [62.5%]). QRS prolongation was comprised of: LBBB (4.2%), right bundle branch block (RBBB, 18.3%), intraventricular conduction delay (9.7%), and ventricularly paced (9.7%). Over 4.09 ± 1.00 years, 769 (52.9%) patients died. Survival was similar between normal and prolonged QRS cohorts with an age and sex adjusted hazard ratio of 1.01 (95%CI: 0.87-1.17, p = 0.16). Recurrent HF hospitalization occurred in 91 (16.7%) with QRS prolongation vs. 90 (9.9%) without (odds ratio: 1.82 [95%CI: 1.33-2.50, p < 0.001]). RBBB carried 2.26 higher odds of recurrent HF hospitalization (95%CI: 1.56-3.28)., Conclusions: Following a HF hospitalization, QRS prolongation increased the odds of re-admission for HF in patients with HFpEF without differences in overall mortality., Competing Interests: Declaration of Competing Interest All authors declare no relevant conflicts of interest. This manuscript is partially the result of work supported with resources and use of facilities of the Minneapolis Veterans Affairs Health Care System. The contents do not represent the views of the U.S. Department of Veterans Affairs or the United States Government., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Introduction: Autonomic dysfunction is common in chronic obstructive pulmonary disease (COPD), and worse autonomic function may be a marker of risk for acute exacerbations of COPD (AECOPD). Heart rate variability (HRV) is a measure of autonomic function. Our objective was to test whether lower (worse) HRV is a risk factor for AECOPD., Methods: We measured standard deviation of normal RR intervals (SDNN) and root mean square of successive RR interval differences (RMSSD) on 10-second electrocardiograms (ECGs) performed at screening and day 42 in participants in the Beta Blockers for the Prevention of Acute Exacerbations of COPD trial ( BLOCK-COPD), a placebo-controlled trial of metoprolol for prevention of AECOPD. We used Cox-proportional hazards models to test if these HRV measures were associated with risk of any AECOPD, and separately, hospitalized AECOPD. We tested associations using baseline HRV measures and incorporating HRV measures from day 42 as a time-varying covariate. We also tested for interactions with metoprolol assignment., Results: Of 532 trial participants, 529 (forced expiratory volume in 1 second [FEV 1 ]41 ± 16.3 % predicted) were included in this analysis. We did not find a significant association between HRV measures and risk of AECOPD when all participants were analyzed together. There was a significant interaction between RMSSD and assignment to metoprolol on time to first hospitalized AECOPD; in the placebo group greater RMSSD was associated with a lower risk of hospitalized AECOPD (adjusted hazard ratio0.71, 95% confidence interval: 0.52 to 0.96, per 10 ms increase) but there was no association in the metoprolol group., Conclusions: Autonomic dysfunction as measured by HRV may be a risk factor for AECOPD. Future studies should analyze longer HRV recordings and their performance in broader samples of people with COPD, including those on beta-blockers., (JCOPDF © 2022.)

Introduction: Left ventricular ejection fraction (EF) ≤ 35% is the cornerstone criterion for implantable cardioverter-defibrillator (ICD) eligibility. Improvement in EF may occur in ICD-eligible patients after coronary artery bypass graft surgery (CABG). However, the incidence, predictors, and outcomes of this process are unclear., Methods and Results: We studied 427 patients with EF ≤ 35% who underwent CABG in the Surgical Treatment for Ischemic Heart Failure (STICH) trial and had a systematic pre- and postoperative (4 months) EF assessment using the identical cardiac imaging modality. All imaging studies were interpreted at a core laboratory. Improvement in EF was defined as postoperative EF > 35% and >5% absolute improvement from baseline. Of the 427 patients (mean age 61.8 ± 9.5 and 50 women), 125 (29.2%) had EF improvement. Their mean EF increased from 26.8% (±5.8%) to 43.3% (±6.5%) (p < .0001). EF improvement occurred in only 20% of patients with a preoperative EF < 25%. The odds of EF improvement were 1.96 times higher (95% confidence interval [CI]: 0.91-4.23, p = .09) in patients with myocardial viability. In adjusted analyses, EF improvement was associated with a significantly lower risk of all-cause mortality (hazard ratio [HR]: 0.58, 95% CI: 0.35-0.96; p = .03) and heart failure mortality (HR: 0.31, 95% CI: 0.11-0.87; p = .027)., Conclusion: Nearly 1/3rd of ICD-eligible patients undergoing CABG had significant improvement in EF, obviating the need for primary prevention ICD implantation. These results provide patients and clinicians data on the likelihood of ICD eligibility after CABG and support the practice of reassessment of EF after revascularization., (© 2021 Wiley Periodicals LLC. This article has been contributed to by US Government employees and their work is in the public domain in the USA.)

Rationale: The chronotropic index quantifies the proportion of the expected heart rate increase that is attained during exercise. The relationship between the chronotropic index and acute exacerbations of chronic obstructive pulmonary disease (AECOPDs) has not been evaluated. Objectives: To determine whether a higher chronotropic index during a 6-minute walk (CI-6MW) is associated with lower risk of AECOPD and whether the CI-6MW is a marker of susceptibility to adverse effects of metoprolol in chronic obstructive pulmonary disease (COPD). Methods: We analyzed data from the BLOCK COPD (Beta-Blockers for the Prevention of AECOPDs) trial. We used Cox proportional hazards models to investigate the relationship between the CI-6MW and the time to AECOPDs. We also tested for interactions between study group assignment (metoprolol vs. placebo) and the CI-6MW on the time to AECOPDs. Results: Four hundred seventy-seven participants with exacerbation-prone COPD (mean forced expiratory volume in 1 second, 41% of predicted) were included in this analysis. A higher CI-6MW was independently associated with a decreased risk of AECOPDs of any severity (adjusted hazard ratio per 0.1 increase in CI-6MW of 0.88; 95% confidence interval, 0.80-0.96) but was not independently associated with AECOPDs requiring hospitalization (adjusted hazard ratio, 0.94; 95% confidence interval, 0.81-1.05). There was a significant interaction by treatment assignment, and in a stratified analysis, the protective effects of a higher CI-6MW on AECOPDs were negated by metoprolol use. Conclusions: A higher CI-6MW is associated with a decreased risk of AECOPDs and may be an indicator of susceptibility to the adverse effects of metoprolol.

Background Sudden cardiac arrest (SCA) risk increases after myocardial infarction (MI) in patients with a reduced ejection fraction (EF). However, the risk factors for SCA among patients with a post-MI EF >35% remain poorly understood. Methods and Results Using the Optum de-identified electronic health record data set from 2008 to 2017, we identified patients with an incident MI diagnosis and troponin elevation who had a post-MI EF >35% and underwent coronary angiography. Primary outcome was SCA within 1 year post-MI. The database was divided into derivation (70%) and validation (30%) cohorts by random selection. Cox proportional hazard regression was used to generate and validate a risk prediction model. Among 31 286 patients with an MI (median age 64.1; 39% female; 87% White), 499 experienced SCA within 1 year post-MI (estimated probability 1.8%). Lack of revascularization at MI, post-MI EF <50%, Black race, renal failure, chronic obstructive pulmonary disease, antiarrhythmic therapy, and absence of beta blocker therapy were independent predictors of SCA. A multivariable model consisting of these variables predicted SCA risk (C-statistic 0.73). Based on this model, the estimated annual probability of SCA was 4.4% (95% CI, 3.9-4.9) in the highest quartile of risk versus 0.6% (95% CI, 0.4-0.8) in the lowest quartile. Conclusions Patients with a post-MI EF >35% have a substantial annual risk of SCA. A risk model consisting of acute coronary revascularization, EF, race, renal failure, chronic obstructive pulmonary disease, antiarrhythmic therapy, and beta blocker therapy can identify patients with higher risk of SCA, who may benefit from further risk stratification and closer monitoring.

Background COVID-19 was temporally associated with an increase in out-of-hospital cardiac arrests, but the underlying mechanisms are unclear. We sought to determine if patients with implantable defibrillators residing in areas with high COVID-19 activity experienced an increase in defibrillator shocks during the COVID-19 outbreak. Methods and Results Using the Medtronic (Mounds View, MN) Carelink database from 2019 and 2020, we retrospectively determined the incidence of implantable defibrillator shock episodes among patients residing in New York City, New Orleans, LA, and Boston, MA. A total of 14 665 patients with a Medtronic implantable defibrillator (age, 66±13 years; and 72% men) were included in the analysis. Comparing analysis time periods coinciding with the COVID-19 outbreak in 2020 with the same periods in 2019, we observed a larger mean rate of defibrillator shock episodes per 1000 patients in New York City (17.8 versus 11.7, respectively), New Orleans (26.4 versus 13.5, respectively), and Boston (30.9 versus 20.6, respectively) during the COVID-19 surge. Age- and sex-adjusted hurdle model showed that the Poisson distribution rate of defibrillator shocks for patients with ≥1 shock was 3.11 times larger (95% CI, 1.08-8.99; P =0.036) in New York City, 3.74 times larger (95% CI, 0.88-15.89; P =0.074) in New Orleans, and 1.97 times larger (95% CI, 0.69-5.61; P =0.202) in Boston in 2020 versus 2019. However, the binomial odds of any given patient having a shock episode was not different in 2020 versus 2019. Conclusions Defibrillator shock episodes increased during the higher COVID-19 activity in New York City, New Orleans, and Boston. These observations may provide insights into COVID-19-related increase in cardiac arrests.

Objective: Examine the trajectory of left ventricular ejection fraction (EF) among patients eligible for implantable cardioverter-defibrillator (ICD) therapy., Background: EF is the cornerstone criterion for ICD therapy, but the risk of sudden cardiac death remains after an improvement in EF., Methods: We examined the trajectory of EF among 1178 participants of the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) who had three or more assessments of EF, at least 90 days apart. A follow-up EF > 35% or >10% absolute increase in EF from baseline were examined as the criteria for EF improvement., Results: At first follow-up, 381 (32%) patients had an improvement of EF to >35%. However, EF had returned back to ≤35% in 109 (27%) of these patients at second follow-up. Similarly, 446 (38%) patients experienced a >10% improvement in EF at first follow-up, but 109 (24%) of these had a subsequent >10% decrease in EF at the second follow-up. Of the 32 patients with normalized EF (≥55%) at first follow-up, 18 (56%) had a subsequent >10% decrease in EF. The fluctuation in EF was present in both ischemic and nonischemic cardiomyopathy but a higher proportion of patients with nonischemic cardiomyopathy had an improvement in EF to >35% at first follow-up compared to those with ischemic cardiomyopathy (38% vs. 27%, p = < .0001)., Conclusion: There is substantial fluctuation of EF among patients who are eligible for ICD therapy., (© 2021 Wiley Periodicals LLC.)

Background: Early MPI after CABG is currently considered rarely appropriate in asymptomatic patients. This study aimed to identify prognostic value of nuclear stress-imaging post-CABG., Methods: This was a single center prospective study looking at long-term outcomes post-CABG. Per protocol participants underwent SPECT-MPI stress testing and coronary angiogram on the same day, 1-year following CABG. Defect size was semi-quantified. The primary outcomes were the composite of death and congestive heart failure., Results: Eighty-four participants underwent nuclear stress-imaging and angiography, with a median follow-up of 11.1 years. Three separate stress findings predicted the primary outcome: inability to reach stage 3 of a Bruce protocol (OR 7.3, CI 2.4-22.1, P < 0.001), LVEF < 45% (OR 4.0, CI 1.1-15.3, P = 0.041) and a moderate-large stress defect size (HR 2.31, CI 1.1-1.5, P = 0.04). These findings appear to be additive and strongest among patients who underwent exercise stress testing (HR 10.6, CI 3.6-30.6, P < 0.001). Graft disease was identified in 39 (46%) patients and compared to those individuals with no graft disease, did not predict long-term adverse outcomes (P = 0.29)., Conclusion: In clinically stable patients early after revascularization with CABG, SPECT-MPI can identify patients at higher risk of heart failure and death.

Background: Hydroxychloroquine (HCQ) has been promoted as a potential treatment of coronavirus disease 2019 (COVID-19), but there are safety concerns., Objective: The purpose of this study was to determine the effects of HCQ treatment on QT interval., Methods: We retrospectively studied the electrocardiograms of 819 patients treated with HCQ for rheumatologic diseases from 2000 to 2020. The primary outcome was corrected QT (QTc) interval, by Bazett formula, during HCQ therapy., Results: Mean patient age was 64.0 ± 10.9 years, and 734 patients (90%) were men. Median dosage of HCQ was 400 mg daily, and median (25th-75th percentile) duration of HCQ therapy was 1006 (471-2075) days. Mean on-treatment QTc was 430.9 ± 31.8 ms. In total, 55 patients (7%) had QTc 470-500 ms, and 12 (1.5%) had QTc >500 ms. Chronic kidney disease (CKD), history of atrial fibrillation (AF), and heart failure were independent risk factors for prolonged QTc. In a subset of 591 patients who also had a pretreatment electrocardiogram, mean QTc increased from 424.4 ± 29.7 ms to 432.0 ± 32.3 ms (P <.0001) during HCQ treatment. Of these patients, 23 (3.9%) had either prolongation of QTc >15% or on-treatment QTc >500 ms. Over median 5.97 (3.33-10.11) years of follow-up, 269 patients (33%) died. QTc >470 ms during HCQ treatment was associated with a greater mortality risk (hazard ratio 1.78; 95% confidence interval 1.16-2.71; P = .008) in univariable but not in multivariable analysis., Conclusion: HCQ is associated with QT prolongation in a significant fraction of patients. The risk of QT prolongation is higher among patients with CKD, AF, and heart failure, who may benefit from greater scrutiny., (Published by Elsevier Inc.)

Background Sudden cardiac death (SCD) is associated with severe coronary heart disease in the great majority of cases. Whether carotid intima-media thickness (C-IMT), a known surrogate marker of subclinical atherosclerosis, is associated with risk of SCD in a general population remains unknown. The objective of this study was to investigate the association between C-IMT and risk of SCD. Methods and Results We examined a total of 20 862 participants: 15 307 participants of the ARIC (Atherosclerosis Risk in Communities) study and 5555 participants of the CHS (Cardiovascular Health Study). C-IMT and common carotid artery intima-media thickness was measured at baseline by ultrasound. Presence of plaque was judged by trained readers. Over a median of 23.5 years of follow-up, 569 participants had SCD (1.81 cases per 1000 person-years) in the ARIC study. Mean C-IMT and common carotid artery intima-media thickness were associated with risk of SCD after adjustment for traditional risk factors and time-varying adjustors: hazard ratios (HRs) with 95% CIs for fourth versus first quartile were 1.64 (1.15-2.63) and 1.49 (1.05-2.11), respectively. In CHS, 302 participants developed SCD (4.64 cases per 1000 person-years) over 13.1 years. Maximum C-IMT was associated with risk of SCD after adjustment: HR (95% CI) for fourth versus first quartile was 1.75 (1.22-2.51). Presence of plaque was associated with 35% increased risk of SCD: HR (95% CI) of 1.37 (1.13-1.67) in the ARIC study and 1.32 (1.04-1.68) in CHS. Conclusions C-IMT was associated with risk of SCD in 2 biracial community-based cohorts. C-IMT may be used as a marker of SCD risk and potentially to initiate early therapeutic interventions to mitigate the risk.

Background: Ventricular tachycardia (VT) is a common arrhythmia in heart failure with reduced ejection fraction but its incidence, predictors, and significance have not been determined in heart failure with preserved ejection fraction (HFpEF)., Methods: We performed a retrospective review of arrhythmias in two cohorts of patients with an HFpEF diagnosis. Patients in cohort 1 (n = 40) underwent routine arrhythmia surveillance with a 14-day ambulatory electrocardiogram (ECG) monitor. Patients in cohort 2 (n = 85) had cardiac pacemakers and underwent routine device interrogations., Results: In cohort 1, 13 patients (32.5%) had one or more episodes of nonsustained VT (NSVT) on ambulatory ECG. In cohort 2, 38 patients (44.7%) had NSVT on cardiac pacemaker interrogations. During a median (interquartile range) follow-up of 3.0 (1.6 to 5.1) years, 15 (12%) patients died (20% of patients with NSVT versus 6.8% of those without NSVT; P = .03). In logistic regression analysis, NSVT was associated with a 3.4-fold higher odds of death (95% confidence interval 1.08 to 10.53; P = .04) in HFpEF., Conclusions: In conclusion, patients with HFpEF have a relatively high, and possibly underappreciated, burden of NSVT, which confers a higher risk of mortality. The frequent episodes of NSVT in these patients may provide insight into the mechanism of sudden cardiac death in HFpEF., (© 2020 Wiley Periodicals LLC.)

Objectives: Frailty is associated with adverse outcomes, but little is known of the impact of frailty on patients with implantable cardioverter defibrillators (ICDs). This study sought to determine the prevalence of frailty, based on quantitative assessment, and assessed its potential impact on outcomes among community-dwelling men with ICDs., Methods: A total of 124 ICD-treated men presenting for a routine device clinic appointment between May and October 2016 underwent frailty assessment consisting of three components: shrinking (weight loss ≥5% during the past year), weakness (inability to rise from a chair without using their arms), and self-reported poor energy level. Patients who had no components were considered robust, those with 1 component were intermediate stage, and those with ≥2 components were deemed frail., Results: Mean age was 70.4 (±9.7) years. Of the 124 men, 31 (25%) were considered to be frail, 65 (52%) were intermediate, and 28 (23%) were robust. Frail men were older and were more likely to have symptomatic heart failure, chronic kidney disease, and hypertension ( P < 0.05 for all) compared with nonfrail men. During a follow-up of 16 months, frail men were significantly more likely to die compared with nonfrail men (29% vs 5.4%, P < 0.0003). The incidence of appropriate ICD shocks (16.1% vs 6.5%) or hospitalizations (38.7% vs 23.7%) tended to be higher among frail versus nonfrail patients, but neither reached statistical significance ( P = 0.10)., Conclusions: Almost one-fourth of men with ICD are frail. Almost one-third of frail ICD patients died within 16 months. It may be useful to assess frailty in patients with ICD.

Purpose: Circadian patterns of ventricular tachyarrhythmias (VTAs) in ICD patients from SCD-HeFT and MADIT-CRT have yielded differing results. The aim was to investigate VTA patterns in a large population of military veterans with ICD., Methods: This retrospective study analyzed biorhythm periodicity of sustained VTAs (≤ 300 ms). Findings were derived from the Veterans Affairs (VA) National Cardiac Device Surveillance database encompassing January 1, 2005, to December 31, 2017., Results: The patient population comprised 1559 consecutive patients with 17,039 VTAs. There were 763 patients with clinical information with the mean age of 67.8 ± 9 years old and 99% male. An hourly non-uniform VTA distribution with a bimodal pattern and a predominant afternoon peak was seen (χ 2  = 5057, P < 0.0001). VTAs treated successfully by anti-tachycardia pacing (ATP) showed a bimodal pattern with even distributions. VTAs treated by ICD shocks showed a bimodal pattern with a predominant afternoon peak. The duration of VTA peaks was increased from 13.5 to 17 h with increasing daylight time from 9.9 to 14.5 h. The weekly VTA distribution showed a significant septadian pattern with lowest frequency on weekend and highest on weekdays (χ 2  = 4840, P < 0.0001). No annual periodicity and monthly periodicity were seen., Conclusions: Sustained VTA events exhibited a circadian rhythm in a large population of military veterans with ICD/CRT-D; specifically, a bimodal pattern with a predominant afternoon peak was observed. Further, the majority of VTA episodes treated by ICD shock occurred in the afternoon, and the duration of VTA peak lengthened with increased duration of daylight time.

Introduction: Epicardial exit sites of ventricular tachycardia (VT) are frequently encountered during VT ablation requiring an epicardial ablation approach for successful elimination of VT. We sought to assess the utility of repolarization markers in identifying individuals requiring an epicardial ablation approach in addition to an endocardial approach., Methods: 32 patients who underwent successful ablation for scar mediated VT were included in the study. Fourteen patients who required a combined endocardial and epicardial VT ablation were defined as epicardial VT group (Epi) whereas 18 patients who were successfully ablated from the endocardium alone constituted the endocardial VT group (Endo). Repolarization markers during sinus rhythm were compared between the two groups., Results: A higher QTc max and QTc dispersion were seen in the Epi group compared to Endo group (479 ± 34 vs 449 ± 20, p = 0.008 and 63 ± 13 vs 38 ± 8, p = 0.001, respectively). Ts-p and Ts-p/Tp-e were higher in the Epi group (166 ± 23 vs 143 ± 23, p = 0.008 and 1.55 ± 0.26 vs 1.3 ± 0.21, p < 0.005). On multivariate regression, QTc dispersion was an independent predictor of the need for an epicardial approach to ablation. A QTc dispersion more than 51.5 msec identified individuals requiring a combined epicardial and endocardial approach to ablation with a sensitivity of 92.9% and a specificity of 100%., Conclusions: Patients requiring an epicardial ablation have a higher QTc dispersion. A value greater than 51.5 msec reliably differentiates between the two groups with high sensitivity and specificity., Competing Interests: Declaration of competing interest None of the authors report potential conflicts of interest pertinent to this report., (Copyright © 2020 Indian Heart Rhythm Society. Production and hosting by Elsevier B.V. All rights reserved.)

Background: Defibrillation threshold testing (DT) following implantable cardioverter defibrillator (ICD) implantation has not shown to improve mortality. However, the impact of DT on burden of heart failure (HF) hospitalisations has not been well defined. Methods: We studied retrospectively consecutive patients who underwent ICD implantation or generator change between 2008 and 2014. Primary outcome was burden of HF hospitalisations within 30 days following implantation. Secondary outcomes were mortality, stroke, and ICD shock within 30 days and one-year mortality. Results: Three hundred and eleven of 501 patients (62%) were in DT+ group versus 190 (38%) were in DT- group. The percentage of new implantations was higher in DT+ group than in DT- group (69% vs 39%, p  < .001) but the distributions of NYHA function classes were similar between two groups. The burden of HF hospitalisations at 30-days was significantly higher in DT+ group than in DT- group (17.4% vs 4.7%, HR 0.842, 95% CI 0.774-0.915, p  < .0001). No difference in mortality, stroke or ICD shocks was found between two groups at 30 days and mortality at 1 year. Conclusions: DT after new ICD or generator replacement was associated with increased HF hospitalisation rates at 30 days after ICD implant in a non-trial HF population. However, there was no association between DT and mortality, stroke and ICD shocks at 30 days or mortality at 1 year. The increased burden of HF hospitalisation in this observational study requires validation by randomised studies.

Background: NT-Pro BNP levels provide incremental value in perioperative risk assessment prior to major noncardiac surgery. Whether they can be pharmacologically modified in patients prior to an elective vascular operation is uncertain., Methods: A double-blind, randomized controlled trial was implemented at a single institution. Patients were screened during their preoperative vascular clinic appointment and randomly assigned to CoQ 10 (400 mg per day) versus Placebo for 3 days prior to surgery. Biomarkers, including NT-Pro BNP, troponin I and C-reactive protein were obtained prior to and following surgery for up to 48 hours. The primary endpoint was postoperative NT-Pro BNP levels, and secondary endpoint measures included myocardial injury, defined by an elevated cardiac troponin level and length of stay., Results: One hundred and twenty-three patients were randomized to receive either CoQ 10 (N = 62) versus Placebo (N = 61) for 3 days before vascular surgery. Preoperative cardiac risks included ischemic heart disease (N = 52), CHF (N = 12), stroke (N = 23), and diabetes mellitus (N = 48) and the planned vascular procedures were infrainguinal (N = 78), carotid (N = 36), and intraabdominal (N = 9). There were no intergroup differences in these clinical variables. NT-Pro BNP levels (median; IQs) in the CoQ 10 and Placebo groups were 179 (75-347) and 217 (109-585) pg/ml, respectively, (P = 0.08) preoperatively, and 397 (211-686) and 591 (288-1,433) pg/ml respectively, (P = 0.01) at 24 hours following surgery. Patients with an elevated NT-Pro BNP had a higher incidence of myocardial injury, (58% vs. 20%; P < 0.01) and a longer hospital stay (4.4 ± 3.8 vs. 2.8 ± 3.2 days; P < 0.02) compared with individuals without an elevated NT-Pro BNP level., Conclusions: NT-Pro BNP levels predict adverse events post-vascular surgery and are lowered in those patients assigned to preoperative administration of CoQ 10 ., Trial Registration: clinicaltrials.gov Identifier: NCT03956017. Among patients undergoing elective vascular surgery, 123 patients were randomized to either CoQ 10 (400 mg/day) versus placebo for three days preoperatively. NT-Pro BNP levels (median; IQs) in the CoQ 10 and Placebo groups were 179 (75-347) and 217 (109-585) pg/ml, respectively, (P = 0.08) preoperatively, and 397 (211-686) and 591 (288-1,433) pg/ml, respectively, (P = 0.01) post-surgery. Patients with an elevated NT-Pro BNP had a higher incidence of myocardial injury (58% vs. 20%; P < 0.01) and a longer hospital stay (4.4 ± 3.8 vs. 2.8 ± 3.2 days; P < 0.02) compared with individuals without an NT-Pro BNP elevation. In conclusion, BNP predicts adverse outcomes and can be reduced with preoperative CoQ 10 ., (Copyright © 2019. Published by Elsevier Inc.)

Background: Sudden cardiac death (SCD) comprises 25% of deaths in patients with heart failure with preserved ejection fraction., Objective: We sought to validate a SCD risk prediction model in patients who participated in the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist Trial., Methods: Of the 3445 Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist Trial participants, 615 (18%) had data on all 6 variables-age, sex, history of myocardial infarction, history of diabetes mellitus, presence of bundle branch block on the electrocardiogram, and N-terminal pro-brain natriuretic peptide level-of the SCD risk prediction model. Those with a 5-year predicted risk of SCD ≥10% were categorized as high risk patients., Results: Over a mean follow-up of 2.9 ± 1.3 years, there were 23 SCDs (3.7%) and 63 deaths from other causes (10.2%). The rate of mortality from SCD and other causes were 13 (95% confidence interval [CI] 9-19) and 35 (95% CI 28-45) per 1000 person-years of follow-up, respectively. A total of 216 participants (35.1%) were categorized as high risk by the SCD risk model. The estimated 5-year cumulative incidence of SCD was 15.2% (95% CI 6.6%-27.2%) in those classified as high risk vs 2.8% (95% CI 1.2%-5.5%) in those classified as low risk. In competing risk analysis, patients predicted to have high SCD risk had a 3.7-fold higher risk of SCD (hazard ratio 3.7; 95% CI 1.6-8.7; P = .003) than did those predicted to have low risk. The SCD risk model yielded a Harrell's C index of 0.74., Conclusion: A SCD risk prediction model including 6 widely available variables can identify patients with heart failure with preserved ejection fraction who had a high risk of SCD., (Published by Elsevier Inc.)

Background and Aims: Abdominal aortic calcification (AAC) and low ankle-brachial index (ABI) are markers of multisite atherosclerosis. We sought to estimate their associations in older men with health care costs and utilization adjusted for each other, and after accounting for CVD risk factors and prevalent CVD diagnoses., Methods: This was an observational cohort study of 2393 community-dwelling men (mean age 73.6 years) enrolled in the Osteoporotic Fractures in Men (MrOS) study and U.S. Medicare Fee for Service (FFS). AAC was scored on baseline lateral lumbar spine X-rays using a 24-point scale. ABI was measured as the lowest ratio of arm to right or left ankle blood pressure. Health care costs, hospital stays, and SNF stays were identified from Medicare FFS claims over 36 months following the baseline visit., Results: Men with AAC score ≥9 (n = 519 [21.7% of analytic cohort]) had higher annualized total health care costs of $1473 (95% C.I. 293, 2654, 2017 U S. dollars) compared to those with AAC score 0-1, after multivariable adjustment. Men with ABI <0.90 (n = 154 [6.4% of analytic cohort]) had higher annualized total health care costs of $2705 (95% CI 634, 4776) compared to men with normal ABI (≥0.9 and < 1.4), after multivariable adjustment., Conclusions: High levels of AAC and low ABI in older men are associated with higher subsequent health care costs, after accounting for clinical CVD risk factors, prevalent CVD diagnoses, and each other. Further investigations of whether preventing progression of peripheral vascular disease and calcification reduces subsequent health care costs are warranted., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: Implantable cardioverter-defibrillators are used to prevent sudden cardiac death in patients with cardiac sarcoidosis. The most recent recommendations for implantable cardioverter-defibrillator implantation in these patients are in the 2017 American Heart Association/American College of Cardiology/Heart Rhythm Society Guideline for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death. These recommendations, based on observational studies or expert opinion, have not been assessed. We aimed to assess them., Methods: We performed a large retrospective cohort study of patients with biopsy-proven sarcoidosis and known or suspected cardiac sarcoidosis that underwent cardiovascular magnetic resonance imaging. Patients were followed for a composite end point of significant ventricular arrhythmia or sudden cardiac death. The discriminatory performance of the Guideline recommendations was tested using time-dependent receiver operating characteristic analyses. The optimal cutoff for the extent of late gadolinium enhancement predictive of the composite end point was determined using the Youden index., Results: In 290 patients, the class I and IIa recommendations identified all patients who experienced the composite end point during a median follow-up of 3.0 years. Patients meeting class I recommendations had a significantly higher incidence of the composite end point than those meeting class IIa recommendations. Left ventricular ejection fraction (LVEF) >35% with >5.7% late gadolinium enhancement on cardiovascular magnetic resonance imaging was as sensitive as and significantly more specific than LVEF >35% with any late gadolinium enhancement. Patients meeting 2 class IIa recommendations, LVEF >35% with the need for a permanent pacemaker and LVEF >35% with late gadolinium enhancement >5.7%, had high annualized event rates. Excluding 2 class IIa recommendations, LVEF >35% with syncope and LVEF >35% with inducible ventricular arrhythmia, resulted in improved discrimination for the composite end point., Conclusions: We assessed the Guideline recommendations for implantable cardioverter-defibrillator implantation in patients with known or suspected cardiac sarcoidosis and identified topics for future research.