Cardiac Challenges in Immune Checkpoint Therapy: Complete Heart Block With Pembrolizumab.

Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment, yet they come with a spectrum of immune-related adverse events, including cardiac complications. We present the case of a 72-year-old male with metastatic renal cell carcinoma who developed complete heart block and ventricular arrhythmias following pembrolizumab therapy. Despite no evidence of myocarditis, the patient's condition rapidly deteriorated, ultimately resulting in his demise. This case underscores the critical need for vigilance in recognizing and managing potential cardiotoxicity associated with ICIs. Additionally, it highlights the importance of multidisciplinary collaboration in optimizing diagnostic and therapeutic strategies for patients undergoing immune checkpoint inhibitor therapy.

Relationship between sex, body size, and cardiac resynchronization therapy benefit: A patient-level meta-analysis of randomized controlled trials.

BACKGROUND: Women might benefit more than men from cardiac resynchronization therapy (CRT) and do so at shorter QRS durations. OBJECTIVE: This meta-analysis was performed to determine whether sex-based differences in CRT effects are better accounted for by height, body surface area (BSA), or left ventricular end-diastolic dimension (LVEDD). METHODS: We analyzed patient-level data from CRT trials (MIRACLE, MIRACLE ICD, MIRACLE ICD II, REVERSE, RAFT, COMPANION, and MADIT-CRT) using bayesian hierarchical Weibull regression models. Relationships between QRS duration and CRT effects were examined overall and in sex-stratified cohorts; additional analyses indexed QRS duration by height, BSA, or LVEDD. End points were heart failure hospitalization (HFH) or death and all-cause mortality. RESULTS: Compared with men (n = 5628), women (n = 1439) were shorter (1.62 [interquartile range, 1.57-1.65] m vs 1.75 [1.70-1.80] m; P < .001), with smaller BSAs (1.76 [1.62-1.90] m2 vs 2.02 [1.89-2.16] m2; P < .001). In adjusted sex-stratified analyses, the reduction in HFH or death was greater for women (hazard ratio, 0.54; credible interval, 0.42-0.70) than for men (hazard ratio, 0.77; credible interval, 0.66-0.89; Pinteraction = .009); results were similar for all-cause mortality even after adjustment for height, BSA, and LVEDD. Sex-specific differences were observed only in nonischemic cardiomyopathy. The effect of CRT on HFH or death was observed at a shorter QRS duration for women (126 ms) than for men (145 ms). Indexing QRS duration by height, BSA, or LVEDD attenuated sex-specific QRS duration thresholds for the effects of CRT on HFH or death but not on mortality. CONCLUSION: Although body size partially explains sex-specific QRS duration thresholds for CRT benefit, it is not associated with the magnitude of CRT benefit. Indexing QRS duration for body size might improve selection of patients for CRT, particularly with a "borderline" QRS duration.

Reassessing the Safety of Pill-in-the-Pocket Propafenone.

The current guidelines state that propafenone can be used in combination with a beta-blocker or a calcium channel blocker for pharmacologic cardioversion of recent-onset atrial fibrillation in patients without structural heart disease. To prevent the conversion from atrial fibrillation to atrial flutter with a rapid ventricular rate, it is recommended to administer propafenone following the administration of a beta-blocker or a calcium channel blocker. However, this combination carries the potential risk of cardiogenic shock. There are several scenarios where this combination can lead to shock, attributed to the variable pharmacokinetics of propafenone among individuals and its significant drug interactions with commonly used AV nodal blockers, such as metoprolol and diltiazem. Additionally, a significant proportion of the population has genetic polymorphisms that affect the metabolism of these medications. While pill-in-the-pocket propafenone is also employed in outpatient settings, unexpected severe and life-threatening reactions have been reported. In this context, we present a case report of severe propafenone toxicity in a closely monitored inpatient setting aimed at converting atrial fibrillation.

Comorbidities and clinical response to cardiac resynchronization therapy: patient-level meta-analysis from eight clinical trials.

AIMS: Patients with heart failure usually have several other medical conditions that might alter the effects of interventions. We investigated whether the burden of comorbidity modified the clinical response to cardiac resynchronization therapy (CRT). METHODS AND RESULTS: Original patient-level data from eight randomized trials exploring the effects of CRT versus no CRT were pooled (BLOCK-HF, MIRACLE, MIRACLE-ICD, MIRACLE-ICD II, RAFT, COMPANION, MADIT-CRT and REVERSE). A prior history of the following comorbidities was considered: episodic or persistent atrial fibrillation (n = 920), coronary artery disease (n = 3732), diabetes (n = 2171), and hypertension (n = 3353). Patients were classified into three groups based on the number of comorbidities: 0, 1-2, or ≥3. The outcomes of interest were time to all-cause mortality and time to the composite outcome of heart failure hospitalization (HFH) or all-cause mortality. Outcomes were evaluated within each comorbidity group using a Bayesian hierarchical Weibull survival regression model. Of 6324 patients, 970 (15%) had no comorbidities, 4052 (64%) had 1-2 and 1302 (21%) had ≥3 comorbidities. The adjusted hazard ratio (aHR) for CRT versus no CRT for all-cause mortality in the overall cohort was 0.79 (95% credible interval [CI] 0.68-0.93) (p = 0.010); for no comorbidities the aHR was 0.54 (95% CI 0.34-0.86), for 1-2 comorbidities was 0.81 (95% CI 0.67-0.97) and for ≥3 comorbidities was 0.83 (95% CI 0.64-1.07) (no significant interaction between CRT and comorbidity burden: p = 0.13). For the endpoint of HFH or all-cause mortality, the aHR for the overall cohort was 0.74 (95% CI 0.65-0.84) (p = 0.001), for no comorbidities was 0.69 (95% CI 0.50-0.94), for 1-2 comorbidities was 0.77 (95% CI 0.66-0.90) and for ≥3 comorbidities was 0.68 (95% CI 0.55-0.82) (no significant interaction between CRT and comorbidity burden: p = 0.081). CONCLUSION: In a meta-analysis of patient-level data from eight major trials, the totality of evidence suggests that CRT reduces HFH and/or all-cause mortality even when several comorbid diseases are present. CLINICAL TRIAL REGISTRATION: NCT00271154, NCT00251251, NCT00267098, NCT00180271.

Cardiac resynchronization therapy in patients with a prior history of atrial fibrillation: Insights from four major clinical trials.

AIMS: To investigate the association of cardiac resynchronization therapy (CRT) on outcomes among participants with and without a history of atrial fibrillation (AF). METHODS: Individual-patient-data from four randomized trials investigating CRT-Defibrillators (COMPANION, MADIT-CRT, REVERSE) or CRT-Pacemakers (COMPANION, MIRACLE) were analyzed. Outcomes were time to a composite of heart failure hospitalization or all-cause mortality or to all-cause mortality alone. The association of CRT on outcomes for patients with and without a history of AF was assessed using a Bayesian-Weibull survival regression model adjusting for baseline characteristics. RESULTS: Of 3964 patients included, 586 (14.8%) had a history of AF; 2245 (66%) were randomized to CRT. Overall, CRT reduced the risk of the primary composite endpoint (hazard ratio [HR]: 0.69, 95% credible interval [CI]: 0.56-0.81). The effect was similar (posterior probability of no interaction = 0.26) in patients with (HR: 0.78, 95% CI: 0.55-1.10) and without a history of AF (HR: 0.67, 95% CI: 0.55-0.80). In these four trials, CRT did not reduce mortality overall (HR: 0.82, 95% CI: 0.66-1.01) without evidence of interaction (posterior probability of no interaction = 0.14) for patients with (HR: 1.09, 95% CI: 0.70-1.74) or without a history of AF (HR: 0.70, 95% CI: 0.60-0.97). CONCLUSION: The association of CRT on the composite endpoint or mortality was not statistically different for patients with or without a history of AF, but this could reflect inadequate power. Our results call for trials to confirm the benefit of CRT recipients with a history of AF.

Cardiac Resynchronization Therapy Improves Outcomes in Patients With Intraventricular Conduction Delay But Not Right Bundle Branch Block: A Patient-Level Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Benefit from cardiac resynchronization therapy (CRT) varies by QRS characteristics; individual randomized trials are underpowered to assess benefit for relatively small subgroups. METHODS: The authors analyzed patient-level data from pivotal CRT trials (MIRACLE [Multicenter InSync Randomized Clinical Evaluation], MIRACLE-ICD [Multicenter InSync ICD Randomized Clinical Evaluation], MIRACLE-ICD II [Multicenter InSync ICD Randomized Clinical Evaluation II], REVERSE [Resynchronization Reverses Remodeling in Systolic Left Ventricular Dysfunction], RAFT [Resynchronization-Defibrillation for Ambulatory Heart Failure], BLOCK-HF [Biventricular Versus Right Ventricular Pacing in Heart Failure Patients with Atrioventricular Block], COMPANION [Comparison of Medical Therapy, Pacing and Defibrillation in Heart Failure], and MADIT-CRT [Multicenter Automatic Defibrillator Implantation Trial - Cardiac Resynchronization Therapy]) using Bayesian Hierarchical Weibull survival regression models to assess CRT benefit by QRS morphology (left bundle branch block [LBBB], n=4549; right bundle branch block [RBBB], n=691; and intraventricular conduction delay [IVCD], n=1024) and duration (with 150-ms partition). The continuous relationship between QRS duration and CRT benefit was also examined within subgroups defined by QRS morphology. The primary end point was time to heart failure hospitalization (HFH) or death; a secondary end point was time to all-cause death. RESULTS: Of 6264 patients included, 25% were women, the median age was 66 [interquartile range, 58 to 73] years, and 61% received CRT (with or without an implantable cardioverter defibrillator). CRT was associated with an overall lower risk of HFH or death (hazard ratio [HR], 0.73 [credible interval (CrI), 0.65 to 0.84]), and in subgroups of patients with QRS ≥150 ms and either LBBB (HR, 0.56 [CrI, 0.48 to 0.66]) or IVCD (HR, 0.59 [CrI, 0.39 to 0.89]), but not RBBB (HR 0.97 [CrI, 0.68 to 1.34]; Pinteraction <0.001). No significant association for CRT with HFH or death was observed when QRS was <150 ms (regardless of QRS morphology) or in the presence of RBBB. Similar relationships were observed for all-cause death. CONCLUSIONS: CRT is associated with reduced HFH or death in patients with QRS ≥150 ms and LBBB or IVCD, but not for those with RBBB. Aggregating RBBB and IVCD into a single "non-LBBB" category when selecting patients for CRT should be reconsidered. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifiers: NCT00271154, NCT00251251, NCT00267098, and NCT00180271.

Cardiac resynchronization therapy outcomes with left ventricular lead concordant with latest mechanical activation: A meta-analysis.

BACKGROUND: For cardiac resynchronization therapy (CRT), image-guided approaches targeting left ventricular (LV) lead placement at the site of latest mechanical activation had inconsistent outcomes. We examined evidence for improved CRT outcomes when LV lead placement concordant with latest mechanical activation occurred. METHODS: A review of EMBASE and PubMed was performed for randomized controlled trials or prospective observational studies from October 2008 through October 2020 comparing outcomes with concordant versus discordant LV lead placement. Meta-analyses were performed to assess the association between concordance and death, death or heart failure (HF) hospitalization, ≥ 15% reduction in LV end systolic volume (LVESV), and changes in LVESV or ejection fraction (LVEF). RESULTS: From 5897 citations, nine publications (eight studies) with 1355 patients were selected; 975 with a concordant LV lead and 380 with a discordant lead. Mean age was 66-68 years, 82% were male, and 64% had ischemic cardiomyopathy. Meta-analyses demonstrated a statistically significant reduction in death/HF hospitalization at 2 years (OR 0.38; 95% CI 0.16, 0.92) and LVESV at 6 months (mean difference [MD] -13.4%; 95% CI -6.7%, -20.0%), and an increase in LVEF (MD 4.03; 95% CI 0.77, 7.30) with the concordant LV lead. There were trends toward decreased death at 2 years (OR 0.49; 95% CI 0.19, 1.23) and ≥ 15% reduction in LVESV at 6 months (OR 3.81; 95% CI 0.24, 61.24) with concordant LV lead placement. CONCLUSION: A concordant LV lead was associated with better CRT outcomes. Further study of feasible methods to achieve LV lead concordance is needed.

Outcomes of Cardiac Resynchronization Therapy with Image-Guided Left Ventricular Lead Placement at the Site of Latest Mechanical Activation: A Systematic Review and Meta-Analysis.

Aim: To assess evidence for an image-guided approach for cardiac resynchronization therapy (CRT) that targets left ventricular (LV) lead placement at the segment of latest mechanical activation. Methods: A systematic review of EMBASE and PubMed was performed for randomized controlled trials (RCTs) and prospective observational studies from October 2008 through October 2020 that compared an image-guided CRT approach with a non-image-guided approach for LV lead placement. Meta-analyses were performed to assess the association between the image-guided approach and NYHA class improvement or changes in end-systolic volume (LVESV), end-diastolic volume (LVEDV), and ejection fraction (LVEF). Results: From 5897 citations, 5 RCTs including 818 patients (426 image-guided and 392 non-image-guided) were identified. The mean age ranged from 66 to 71 years, 76% were male, and 53% had ischemic cardiomyopathy. Speckle tracking echocardiography was the primary image-guided method in all studies. LV lead placement within the segment of the latest mechanical activation (concordant) was achieved in the image-guided arm in 45% of the evaluable patients. There was a statistically significant improvement in the NYHA class at 6 months (odds ratio 1.66; 95% confidence interval (CI) [1.02, 2.69]) with the image-guided approach, but no statistically significant change in LVESV (MD -7.1%; 95% CI [-16.0, 1.8]), LVEDV (MD -5.2%; 95% CI [-15.8, 5.4]), or LVEF (MD 0.68; 95% CI [-4.36, 5.73]) versus the non-image-guided approach. Conclusion: The image-guided CRT approach was associated with improvement in the NYHA class but not echocardiographic measures, possibly due to the small sample size and a low rate of concordant LV lead placement despite using the image-guided approach. Therefore, our meta-analysis was not able to identify consistent improvement in CRT outcomes with an image-guided approach.

Red herring pathogenic variants: a case report of premature ventricular contraction-triggered ventricular fibrillation with an incidental pathogenic LMNA variant.

Background: Pathogenic variants in the lamin A/C gene (LMNA) can lead to a wide range of phenotypes from dilated and arrhythmogenic cardiomyopathies and conduction abnormalities to partial lipodystrophies. This case highlights a coincidental pathogenic LMNA variant identified in a patient with sudden cardiac arrest (SCA). We demonstrate the need for careful interpretation of pathogenic variants identified in cardiomyopathy genes by highlighting a case in which a coincidental pathogenic LMNA variant was found in a patient with premature ventricular complex (PVC)-induced ventricular fibrillation (VF). Case summary: We present the case of a 16-year-old male with SCA secondary to VF. Genetic testing identified a maternally inherited pathogenic variant in LMNA annotated c.1961dup; p.T655Nfs*49. The patient received an implantable cardiac defibrillator and was discharged on nadolol. The patient's two brothers were also variant-positive. However, the patient and both brothers had normal chamber dimensions on echocardiogram and no late gadolinium enhancement on cardiac magnetic resonance imaging. The family members with the variant were recommended to have prophylactic implantable cardiac defibrillators and thus sought a second opinion. The patient received an appropriate shock and device interrogation identified PVCs. Electrophysiology study identified PVC-induced VF which was ablated with no recurrent ventricular arrhythmias/implantable cardioverter defibrillator therapies over 8 months of follow-up. Although the variant in LMNA could lead to cardiac arrest, the clinical phenotype was consistent with a non-genetic aetiology. The family members were told to have periodic cardiac evaluation. Discussion: This case demonstrates the identification of a coincidental pathogenic variant in a cardiomyopathy gene in a patient with cardiac arrest. Although this variant could lead to cardiomyopathy, it appears the cardiac arrest was not due to the pathogenic variant. This highlights the need to consider the clinical phenotype when interpreting genetic test results for cardiomyopathies even in the presence of a positive genetic test result.

Arrhythmias in Female Patients: Incidence, Presentation and Management.

There is a growing appreciation for differences in epidemiology, treatment, and outcomes of cardiovascular conditions by sex. Historically, cardiovascular clinical trials have under-represented females, but findings have nonetheless been applied to clinical care in a sex-agnostic manner. Thus, much of the collective knowledge about sex-specific cardiovascular outcomes result from post hoc and secondary analyses. In some cases, these investigations have revealed important sex-based differences with implications for optimizing care for female patients with arrhythmias. This review explores the available evidence related to cardiac arrhythmia care among females, with emphasis on areas in which important sex differences are known or suggested. Considerations related to improving female enrollment in clinical trials as a way to establish more robust clinical evidence for the treatment of females are discussed. Areas of remaining evidence gaps are provided, and recommendations for areas of future research and specific action items are suggested. The overarching goal is to improve appreciation for sex-based differences in cardiac arrhythmia care as 1 component of a comprehensive plan to optimize arrhythmia care for all patients.

Right ventricular lead location and outcomes among patients with cardiac resynchronization therapy: A meta-analysis.

BACKGROUND: Cardiac resynchronization therapy (CRT) has been demonstrated to improve heart failure (HF) symptoms, reverse LV remodeling, and reduce mortality and HF hospitalization (HFH) in patients with a reduced left ventricular (LV) ejection fraction (LVEF). Prior studies examining outcomes based on right ventricular (RV) lead position among CRT patients have provided mixed results. We performed a systematic review and meta-analysis of randomized controlled trials and prospective observational studies comparing RV apical (RVA) and non-apical (RVNA) lead position in CRT. METHODS: Our meta-analysis was constructed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for systematic reviews and meta-analyses. We searched EMBASE and MEDLINE. Eligible studies reported on at least one of the following outcomes of interest: all-cause mortality, the composite endpoint of death and first HFH hospitalization, change in LVEF, New York Heart Association (NYHA) class improvement, and change in LV end systolic volume (LVESV). We performed meta-analysis summaries using a DerSimonian-Laird random-effects model and conservatively used the Knapp-Hartung approach to adjust the standard errors of the estimated model coefficients. RESULTS: We included nine studies representing a total of 1832 patients. Of those, 1318 (72%) patients had RVA lead placement and 514 (28%) had RVNA lead placement. The mean age of patients was 65.5 ± 4.4 years, and they were predominantly men (69%-97%). There was no statistically significant difference in all-cause mortality by RVA vs. RVNA (OR = 0.77, 95% CI 0.32-1.89; I2 = 16.7%, p = 0.31), or in the combined endpoint of all-cause mortality and first HFH (OR 0.88, 95% CI 0.62-1.25; I2 = 0%, p = 0.84). Also, there was no difference between RVA and RVNA for NYHA class improvement (OR = 1.03, 95% CI 0.9-1.17; I2 = 0%, p = 0.99), change in LVEF (mean difference (MD) = 1.33, 95% CI -1.45 to 4.10; I2 = 47%; p = 0.093), and change in LVESV (MD = -1.11, 95% CI -3.34 to 1.12; I2 = 0%; p = 0.92). CONCLUSION: This meta-analysis shows that in CRT pacing, RV lead position does not appear to be associated with clinical outcomes or LV reverse remodeling. Further studies should focus on the relationship of RV lead vis-à-vis LV lead location, and its clinical importance.

Shared decision-making in atrial fibrillation: patient-reported involvement in treatment decisions.

AIMS: To determine the extent of shared decision-making (SDM), during selection of oral anticoagulant (OAC) and rhythm control treatments, in patients with newly diagnosed atrial fibrillation (AF). METHODS AND RESULTS: We evaluated survey data from 1006 patients with new-onset AF enrolled at 56 US sites participating in the SATELLITE substudy of the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT II). Patients completed surveys at enrolment and at 6-month follow-up. Patients were asked about who made their AF treatment decisions. Shared decision-making was classified as one that the patient felt was an autonomous decision or a shared decision with their healthcare provider (HCP). Approximately half of patients reported that their OAC treatment decisions were made entirely by their HCP. Compared with those reporting no SDM, patients reporting SDM for OAC were more often female (47.2% vs. 38.4%), while patients reporting SDM for rhythm control were more often male (62.2% vs. 57.6%). The most important factors cited by patients during decision-making for OAC were reducing stroke and bleeding risk, and their HCP's recommendations. After adjustment, patients with self-reported understanding of OAC, and rhythm control options, had higher odds of having participated in SDM [odds ratio (OR) 2.54, confidence interval (CI): 1.75-3.68 and OR 2.36, CI: 1.50-3.71, both P ≤ 0.001, respectively]. CONCLUSION: Shared decision-making is not widely implemented in contemporary AF practice. Patient understanding about available therapeutic options is associated with a more than a two-fold higher likelihood of SDM, and may be a potential target for future interventions.

Future research prioritization in cardiac resynchronization therapy.

BACKGROUND: Although cardiac resynchronization therapy (CRT) is effective for some patients with heart failure and a reduced left ventricular ejection fraction (HFrEF), evidence gaps remain for key clinical and policy areas. The objective of the study was to review the data on the effects of CRT for patients with HFrEF receiving pharmacological therapy alone or pharmacological therapy and an implantable cardioverter-defibrillator (ICD) and then, informed by a diverse group of stakeholders, to identify evidence gaps, prioritize them, and develop a research plan. METHODS: Relevant studies were identified using PubMed and EMBASE and ongoing trials using clinicaltrials.gov. Forced-ranking prioritization method was applied by stakeholders to reach a consensus on the most important questions. Twenty-six stakeholders contributed to the expanded list of evidence gaps, including key investigators from existing randomized controlled trials and others representing different perspectives, including patients, the public, device manufacturers, and policymakers. RESULTS: Of the 18 top-tier evidence gaps, 8 were related to specific populations or subgroups of interest. Seven were related to the comparative effectiveness and safety of CRT interventions or comparators, and 3 were related to the association of CRT treatment with specific outcomes. The association of comorbidities with CRT effectiveness ranked highest, followed by questions about the effectiveness of CRT among patients with atrial fibrillation and the relationship between gender, QRS morphology and duration, and outcomes for patients either with CRT plus ICD or with ICD. CONCLUSIONS: Evidence gaps presented in this article highlight numerous, important clinical and policy questions for which there is inconclusive evidence on the role of CRT and provide a framework for future collaborative research.

Periprocedural Risk and Survival Associated With Implantable Cardioverter-Defibrillator Placement in Older Patients With Advanced Heart Failure.

Importance: Little is known about the utilization rates and outcomes of implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy defibrillator (CRT-D) placement among patients with advanced heart failure (HF). Objective: To examine utilization rates, patient characteristics, and outcomes of ICD and CRT-D placements among patients with advanced HF. Design, Setting, and Participants: This cohort study was a post hoc analysis of 81 492 Medicare fee-for-service beneficiaries enrolled in the National Cardiovascular Data Registry ICD Registry between January 2010 and December 2014. Inclusion criteria were patients who had received an HF diagnosis, had a left ventricular ejection fraction of 35% or lower, and showed evidence of advanced HF, which was defined as New York Heart Association (NYHA) class IV symptoms, inotrope use within the last 60 days, left ventricular assist device in situ, or orthotopic heart transplant listing. The comparator group included patients with NYHA class II and no HF hospitalization within the last 12 months, no left ventricular assist device, no orthotopic heart transplant listing, and no current or recent inotrope use. All eligible patients underwent first-time ICD or CRT-D placement for primary prevention of sudden cardiac death. Data were analyzed from January 2010 to December 2014. Main Outcomes and Measures: All-cause mortality and periprocedural complications. Results: Of 81 492 Medicare patients, 3343 had advanced HF (4.1%) and 19 424 were in the comparator group (23.8%). Among the advanced HF population, the mean (SD) age of patients was 74 (9) years, and patients were predominantly white individuals (81.5%) and men (71.1%). The all-cause mortality rate at 30 days was 3.1% (95% CI, 2.6%-3.8%) in the advanced HF group vs 0.5% (0.4%-0.6%) in the comparator group (P < .001). In the advanced HF population, the aggregate in-hospital periprocedural complication rate was 3.74% (95% CI, 3.12%-4.44%) vs 1.10% (95% CI, 0.95%-1.25%) in the comparator group (P < .001). Most adverse events in this group were in-hospital fatality (1.82%; 95% CI, 1.40%-2.34%) and resuscitated cardiac arrest (1.05%; 95% CI, 0.73%-1.45%). Patients with NYHA class IV (hazard ratio, 1.40; 95% CI, 1.02-1.93; P = .04), ischemic heart disease (hazard ratio, 1.24; 95% CI, 1.04-1.48; P = .02), or diabetes (hazard ratio, 1.17; 95% CI, 1.04-1.33; P = .01) had a higher risk of death. Conclusions and Relevance: Among patients undergoing ICD or CRT-D placement for primary prevention of sudden cardiac death, only a small proportion had advanced HF. These patients experienced clinically important periprocedural complication rates associated with in-hospital death and cardiac arrest relative to patients with nonadvanced HF.

Sudden cardiac death in patients with myocarditis: Evaluation, risk stratification, and management.

Myocarditis is a major cause of sudden cardiac death (SCD) and dilated cardiomyopathy (DCM) in young adults. Cardiac magnetic resonance is the established tool for the diagnosis of myocarditis, and late gadolinium enhancement detected on cardiac magnetic resonance imaging is the strongest independent predictor of SCD, all-cause mortality, and cardiac mortality. Several other factors have been associated with SCD or cardiac transplantation including New York Heart Association functional class III/IV, reduced left ventricular ejection fraction <35%, and right ventricular ejection fraction ≤45%. A fragmented QRS and a prolonged QTc interval on an electrocardiogram are predictors of VAs. The postulated mechanism of VA in acute myocarditis is ion channel dysfunction and inflammation that alter intracellular signaling, producing interstitial edema and fibrosis and thereby causing conduction abnormalities. VAs in chronic myocarditis are generally due to scar-mediated reentry. Treatment of myocarditis is tailored toward supportive care and symptomatic relief. The subset of patients who develop DCM should be treated with heart failure medications according to professional guideline recommendations. Indications for an implantable cardioverter-defibrillator are similar to those for nonischemic cardiomyopathy; however, an implantable cardioverter-defibrillator should be held in the acute phase of myocarditis to allow left ventricular ejection fraction recovery, and a wearable cardioverter-defibrillator may be beneficial for some patients. Antiarrhythmic medications are reserved for patients with symptomatic nonsustained or sustained VAs. Radiofrequency ablation appears to be an effective treatment option for VAs; however, more data on its safety and effectiveness are needed. This review addresses risk factors of SCD and VAs in patients with myocarditis with special emphasis on treatment and prevention of these outcomes.

Physicians' perceptions of shared decision-making for implantable cardioverter-defibrillators: Results of a physician survey.

BACKGROUND: Centers for Medicare and Medicaid Services has mandated the use of shared decision-making (SDM) for implantable cardioverter-defibrillator (ICD) implantation. SDM tools help facilitate quality SDM by presenting patients with balanced evidence-based facts related to risk and benefits. Perceptions of ICD implantation may differ based on patients' sex and race. OBJECTIVE: To determine if and how physicians are incorporating SDM in counseling patients about ICD and if they are aware of sex- and race-based differences in patients' perception of ICDs. METHODS: This was a pilot study involving an online survey targeting attending physicians who implant ICDs. Physicians were randomly selected by a computer-based program; 350 surveys were sent. RESULTS: Of the 124 (35%) respondents to the survey, 102 (84%) met the inclusion criteria, and of those, 99 (97%) were adult electrophysiologists. Most physicians (90, 88%) stated they engaged in SDM during the general consent process. Sixty-three (62%) physicians discuss end of life issues while obtaining general consent. Forty-four (43%) physicians said they use an existing SDM tool with the Colorado SDM tool being the most common (39, 89%). The majority of physicians were unaware of sex- and race-based differences in perceptions related to ICD implantation (sex 64, 63% and race 63, 62%). CONCLUSION: A vast majority of physicians are engaging in SDM; however less than half are using a formal SDM tool, and a minority of physicians were aware of sex- and race-based differences in patients' perception of ICD implantation. Sex- and race-based tools might help address this gap.

Intravenous Tissue Plasminogen Activator in Stroke Mimics.

BACKGROUND: The necessity for rapid evaluation and treatment of acute ischemic stroke with intravenous tPA (tissue-type plasminogen activator) may increase the risk of administrating tPA to patients presenting with noncerebrovascular conditions that closely resemble stroke (stroke mimics). However, there are limited data on thrombolysis safety in stroke mimics. METHODS AND RESULTS: Using data from the Get With The Guidelines-Stroke Registry, we identified 72 582 patients with suspected ischemic stroke treated with tPA from 485 US hospitals between January 2010 and December 2017. We documented the use of tPA in stroke mimics, defined as patients who present with stroke-like symptoms, but after workup are determined not to have suffered from a stroke or transient ischemic attack, and compared characteristics and outcomes in stroke mimics versus those with ischemic stroke. Overall, 3.5% of tPA treatments were given to stroke mimics. Among them, 38.2% had a final nonstroke diagnoses of migraine, functional disorder, seizure, and electrolyte or metabolic imbalance. Compared with tPA-treated true ischemic strokes, tPA-treated mimics were younger (median 54 versus 71 years), had a less severe National Institute of Health Stroke Scale (median 6 versus 8), and a lower prevalence of cardiovascular risk factors, except for a higher prevalence of prior stroke/transient ischemic attack (31.3% versus 26.1%, all P<0.001). The rate of symptomatic intracranial hemorrhage was lower in stroke mimics (0.4%) as compared with 3.5% in ischemic strokes (adjusted odds ratio, 0.29; 95% CI, 0.17-0.50). In-hospital mortality rate was significantly lower in stroke mimics (0.8% versus 6.2%, adjusted odds ratio, 0.31; 95% CI, 0.20-0.49). Patients with stroke mimics were more likely to be discharged to home (83.8% versus 49.3%, adjusted odds ratio, 2.97; 95% CI, 2.59-3.42) and to ambulate independently at discharge (78.6% versus 50.6%, adjusted odds ratio, 1.86; 95% CI, 1.61-2.14). CONCLUSIONS: In this large cohort of patients treated with tPA, relatively few patients who received tPA for presumed stroke were ultimately not diagnosed with a stroke or transient ischemic attack. The complication rates associated with tPA in stroke mimics were low. Despite the potential risk of administering tPA to stroke mimics, opportunity remains for continued improvement in the rapid and accurate diagnosis and treatment of ischemic stroke.

High-power, low-flow, short-ablation duration-the key to avoid collateral injury?

BACKGROUND: A common approach to ablating along the posterior wall of the left atrium in atrial fibrillation ablation is to use low power with longer duration for durable lesions and reducing thermal injury. We hypothesize that similar lesions can be safely obtained at high power with low open-irrigation flow and low duration. METHODS: Twenty-two porcine ventricles were placed in a tissue bath with circulating 0.45% NaCl at a maintained temperature of 37 °C. Bipolar radiofrequency ablation (RFA) with a 4-mm-tip irrigated, force-sensing catheter was performed with various combinations of irrigation, power, and duration at 20g of contact force. Fiber optic temperature probes were placed at depths of 3 mm and 5 mm. Temperature was measured during and 30 s after each ablation. RESULTS: Two hundred sixty-eight lesions were made. At a fixed power and flow rate, lesion surface diameter, maximum lesion width, and lesion depth all increased with longer ablation duration. At fixed duration and irrigation flow rate, increased power led to increased lesion dimensions. At a lower flow rate (2 ml/min), surface lesion diameter and maximum width were significantly larger compared to a higher flow rate (17 ml/min), but lesion depth was not significantly different. The maximum temperature and the rate of temperature rise at a depth of 5 mm with different power settings and ablation durations were lower as compared to a depth of 3 mm at both flow rates (2 ml/min and 17 ml/min). CONCLUSIONS: Effective lesions can be performed with high-power and short-ablation durations, thereby reducing RFA procedure time. Higher power, shorter duration lesions result in adequate temperature for myocardial lesion formation at 3 mm, but do not result in excessive temperature at 5 mm depth, potentially reducing the risk of collateral injury. Compared to higher irrigation flow rate, larger surface lesions and comparable maximum lesion width are achieved with lower irrigation flow rate, thus resulting in better lesion contiguity.