Cardiac Resynchronization Therapy in Ischemic Versus Nonischemic Cardiomyopathy: Patient-Level Meta-Analysis of 7 Randomized Clinical Trials.

BACKGROUND: Data on whether cardiac resynchronization therapy (CRT) results in better clinical and echocardiographic outcomes in patients with nonischemic cardiomyopathy (NICM) vs ischemic cardiomyopathy (ICM) are conflicting. OBJECTIVES: The authors conducted this meta-analysis of 7 clinical trials of CRT to determine the association between etiology of cardiomyopathy and clinical and echocardiographic outcomes. METHODS: The authors analyzed patient-level data using Bayesian Hierarchical Weibull survival regression modeling to determine the association between etiology of cardiomyopathy and time to all-cause death or heart failure hospitalization (HFH). Linear regression was used to assess the association between etiology of cardiomyopathy and echocardiographic measurements. RESULTS: Of 6,252 patients included, 4,717 (75%) were men, median age was 66 years (IQR: 58-73 years), 3,704 (59%) had ICM, and 3,778 (60%) received CRT. CRT increased the time to HFH or all-cause death (HR: 0.67; 95% credible interval [CrI]: 0.56-0.82; P < 0.001) with no difference by etiology of cardiomyopathy (HR ratio: 1.06 [95% CrI: 0.87-1.29]; P = 0.57). Likewise, CRT increased the time to all-cause death (HR: 0.71 [95% CrI: 0.55-0.93]; P = 0.019) with no difference by etiology of cardiomyopathy (HR ratio: 1.06 [95% CrI: 0.80-1.43]; P = 0.70). Echocardiographic data that were available for 2,430 (39%) patients showed that CRT improvements in left ventricular ejection fraction, left ventricular end-diastolic diameter, and left ventricular end-systolic diameter were larger for patients with NICM. CONCLUSIONS: Although CRT led to greater increases in left ventricular ejection fraction and reductions in ventricular dimensions for patients with NICM compared with those with ICM, CRT significantly increased the time to HFH or all-cause death independently of the etiology of cardiomyopathy. Further studies on improving patient selection for CRT are needed.

Cardiac Implantable Electronic Device Patient Follow-Up: Assessment of U.S. Practice.

BACKGROUND: A 2015 expert consensus statement recommended that patients with cardiac implantable electronic devices receive remote monitoring and at least 1 in-office evaluation annually. OBJECTIVE: We examined whether patients who underwent implantation of a new cardiac implantable electronic device received care concordant with consensus statement recommendations. METHODS: We examined the rate of follow-up office visits and remote monitoring for 211,346 Medicare beneficiaries with an implantation of a new cardiac implantable electronic device between October 2015 and December 2020. We also assessed the characteristics of patients receiving follow-up care. RESULTS: Within 16 weeks of implantation 77.8% of patients were seen in-office for a post-operative evaluation. The percentage of patients seen in office was 85.9% in the first 12 months, with 64.2% of patients seen in office every two years post-implantation, respectively. Following implantation, the percentage of beneficiaries receiving remote monitoring in the first 91 days was 14.7%, with 4.4% patients receiving remote monitoring every 91 days post-implantation within the first year. Patients who were ≥ 85 years old, non-white, or of lower income were less likely to receive office visits post-implantation. CONCLUSIONS: While most Medicare beneficiaries were seen in-office in the year following a new implant, the percentage of beneficiaries with an in-office visit declined in subsequent years. Fewer than five percent of beneficiaries had remote monitoring at the frequency recommended by the expert consensus statement. Patient demographics, including older age, non-white race, and lower income were associated with a lower likelihood of receiving care concordant with consensus statement recommendations.

State of the art of mobile health technologies use in clinical arrhythmia care.

The rapid growth in consumer-facing mobile and sensor technologies has created tremendous opportunities for patient-driven personalized health management. The diagnosis and management of cardiac arrhythmias are particularly well suited to benefit from these easily accessible consumer health technologies. In particular, smartphone-based and wrist-worn wearable electrocardiogram (ECG) and photoplethysmography (PPG) technology can facilitate relatively inexpensive, long-term rhythm monitoring. Here we review the practical utility of the currently available and emerging mobile health technologies relevant to cardiac arrhythmia care. We discuss the applications of these tools, which vary with respect to diagnostic performance, target populations, and indications. We also highlight that requirements for successful integration into clinical practice require adaptations to regulatory approval, data management, electronic medical record integration, quality oversight, and efforts to minimize the additional burden to health care professionals.

JACC: Advances Expert Panel Perspective: Shared Decision-Making in Multidisciplinary Team-Based Cardiovascular Care.

Shared decision-making (SDM) and multidisciplinary team-based care delivery are recommended across several cardiology clinical practice guidelines. However, evidence for benefit and guidance on implementation are limited. Informed consent, the use of patient decision aids, or the documentation of these elements for governmental or societal agencies may be conflated as SDM. SDM is a bidirectional exchange between experts: patients are the experts on their goals, values, and preferences, and clinicians provide their expertise on clinical factors. In this Expert Panel perspective, we review the current state of SDM in team-based cardiovascular care and propose best practice recommendations for multidisciplinary team implementation of SDM.

RAndomized Cluster Evaluation of Cardiac ARrest Systems (RACE-CARS) trial: Study rationale and design.

Out-of-hospital cardiac arrest (OHCA) occurs in nearly 350,000 people each year in the United States (US). Despite advances in pre and in-hospital care, OHCA survival remains low and is highly variable across systems and regions. The critical barrier to improving cardiac arrest outcomes is not a lack of knowledge about effective interventions, but rather the widespread lack of systems of care to deliver interventions known to be successful. The RAndomized Cluster Evaluation of Cardiac ARrest Systems (RACE-CARS) trial is a 7-year pragmatic, cluster-randomized trial of 62 counties (57 clusters) in North Carolina using an established registry and is testing whether implementation of a customized set of strategically targeted community-based interventions improves survival to hospital discharge with good neurologic function in OHCA relative to control/standard care. The multifaceted intervention comprises rapid cardiac arrest recognition and systematic bystander CPR instructions by 9-1-1 telecommunicators, comprehensive community CPR training and enhanced early automated external defibrillator (AED) use prior to emergency medical systems (EMS) arrival. Approximately 20,000 patients are expected to be enrolled in the RACE CARS Trial over 4 years of the assessment period. The primary endpoint is survival to hospital discharge with good neurologic outcome defined as a cerebral performance category (CPC) of 1 or 2. Secondary outcomes include the rate of bystander CPR, defibrillation prior to arrival of EMS, and quality of life. We aim to identify successful community- and systems-based strategies to improve outcomes of OHCA using a cluster randomized-controlled trial design that aims to provide a high level of evidence for future application.

Outcomes of Cardiac Resynchronization Therapy by New York Heart Association Class: A Patient-Level Meta-Analysis.

BACKGROUND: Data on the benefits of cardiac resynchronization therapy (CRT) in patients with severe heart failure symptoms are limited. We investigated the relative effects of CRT in patients with ambulatory New York Heart Association (NYHA) IV versus III functional class at the time of device implantation. METHODS AND RESULTS: In this meta-analysis, we pooled patient-level data from the MIRACLE (Multicenter InSync Randomized Clinical Evaluation), MIRACLE-ICD (Multicenter InSync Implantable Cardioversion Defibrillation Randomized Clinical Evaluation), and COMPANION (Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure) trials. Outcomes evaluated were time to the composite end point of the first heart failure hospitalization or all-cause mortality, and time to all-cause mortality alone. The association between CRT and outcomes was evaluated using a Bayesian hierarchical Weibull survival regression model. We assessed if this association differed between NYHA III and IV groups by adding an interaction term between CRT and NYHA class as a random effect. A sensitivity analysis was performed by including data from RAFT (Resynchronization-Defibrillation for Ambulatory Heart Failure). Our pooled analysis included 2309 patients. Overall, CRT was associated with a longer time to heart failure hospitalization or all-cause mortality (adjusted hazard ratio [aHR], 0.79 [95% credible interval [CI], 0.64-0.99]; posterior probability or P=0.044), with a similar association with time to all-cause mortality (aHR, 0.78 [95% CI, 0.59-1.03]; P=0.083). Associations of CRT with outcomes were not significantly different for those in NYHA III and IV classes (ratio of aHR, 0.72 [95% CI, 0.30-1.27]; P=0.23 for heart failure hospitalization/mortality; ratio of aHR, 0.70 [95% CI, 0.35-1.34]; P=0.27 for all-cause mortality alone). The sensitivity analysis, including RAFT data, did not show a significant relative CRT benefit between NYHA III and IV classes. CONCLUSIONS: Overall, there was no significant difference in the association of CRT with either outcome for patients in NYHA functional class III compared with functional class IV.

The potential of artificial intelligence to revolutionize health care delivery, research, and education in cardiac electrophysiology.

The field of electrophysiology (EP) has benefited from numerous seminal innovations and discoveries that have enabled clinicians to deliver therapies and interventions that save lives and promote quality of life. The rapid pace of innovation in EP may be hindered by several challenges including the aging population with increasing morbidity, the availability of multiple costly therapies that, in many instances, confer minor incremental benefit, the limitations of healthcare reimbursement, the lack of response to therapies by some patients, and the complications of the invasive procedures performed. To overcome these challenges and continue on a steadfast path of transformative innovation, the EP community must comprehensively explore how artificial intelligence (AI) can be applied to healthcare delivery, research, and education and consider all opportunities in which AI can catalyze innovation; create workflow, research, and education efficiencies; and improve patient outcomes at a lower cost. In this white paper, we define AI and discuss the potential of AI to revolutionize the EP field. We also address the requirements for implementing, maintaining, and enhancing quality when using AI and consider ethical, operational, and regulatory aspects of AI implementation. This manuscript will be followed by several perspective papers that will expand on some of these topics.

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.

Benefit of cardiac resynchronization therapy among older patients: A patient-level meta-analysis.

BACKGROUND: Cardiac resynchronization therapy (CRT) reduces heart failure hospitalizations (HFH) and mortality for guideline-indicated patients with heart failure (HF). Most patients with HF are aged ≥70 years but such patients are often under-represented in randomized trials. METHODS: Patient-level data were combined from 8 randomized trials published 2002-2013 comparing CRT to no CRT (n = 6,369). The effect of CRT was estimated using an adjusted Bayesian survival model. Using age as a categorical (<70 vs ≥70 years) or continuous variable, the interaction between age and CRT on the composite end point of HFH or all-cause mortality or all-cause mortality alone was assessed. RESULTS: The median age was 67 years with 2436 (38%) being 70+; 1,554 (24%) were women; 2,586 (41%) had nonischemic cardiomyopathy and median QRS duration was 160 ms. Overall, CRT was associated with a delay in time to the composite end point (adjusted hazard ratio [aHR] 0.75, 95% credible interval [CI] 0.66-0.85, P = .002) and all-cause mortality alone (aHR of 0.80, 95% CI 0.69-0.96, P = .017). When age was treated as a categorical variable, there was no interaction between age and the effect of CRT for either end point (P > .1). When age was treated as a continuous variable, older patients appeared to obtain greater benefit with CRT for the composite end point (P for interaction = .027) with a similar but nonsignificant trend for mortality (P for interaction = .35). CONCLUSION: Reductions in HFH and mortality with CRT are as great or greater in appropriately indicated older patients. Age should not be a limiting factor for the provision of CRT.

Point-of-Care Chemistry-Guided Dialysate Adjustment to Reduce Arrhythmias: A Pilot Trial.

Introduction: Excessive dialytic potassium (K) and acid removal are risk factors for arrhythmias; however, treatment-to-treatment dialysate modification is rarely performed. We conducted a multicenter, pilot randomized study to test the safety, feasibility, and efficacy of 4 point-of-care (POC) chemistry-guided protocols to adjust dialysate K and bicarbonate (HCO3) in outpatient hemodialysis (HD) clinics. Methods: Participants received implantable cardiac loop monitors and crossed over to four 4-week periods with adjustment of dialysate K or HCO3 at each treatment according to pre-HD POC values: (i) K-removal minimization, (ii) K-removal maximization, (iii) Acidosis avoidance, and (iv) Alkalosis avoidance. The primary end point was percentage of treatments adhering to the intervention algorithm. Secondary endpoints included pre-HD K and HCO variability, adverse events, and rates of clinically significant arrhythmias (CSAs). Results: Nineteen subjects were enrolled in the study. HD staff completed POC testing and correctly adjusted the dialysate in 604 of 708 (85%) of available HD treatments. There was 1 K ≤3, 29 HCO3 <20 and 2 HCO3 >32 mEq/l and no serious adverse events related to study interventions. Although there were no significant differences between POC results and conventional laboratory measures drawn concurrently, intertreatment K and HCO3 variability was high. There were 45 CSA events; most were transient atrial fibrillation (AF), with numerically fewer events during the alkalosis avoidance period (8) and K-removal maximization period (3) compared to other intervention periods (17). There were no significant differences in CSA duration among interventions. Conclusion: Algorithm-guided K/HCO3 adjustment based on POC testing is feasible. The variability of intertreatment K and HCO3 suggests that a POC-laboratory-guided algorithm could markedly alter dialysate-serum chemistry gradients. Definitive end point-powered trials should be considered.

Colchicine for the Prevention of Recurrent Arrhythmia After Catheter Ablation of Atrial Fibrillation: Results of a Single-Center, Retrospective Study.

BACKGROUND: There is evidence to suggest that colchicine reduces the risk of recurrent atrial fibrillation (AF) after catheter ablation; however, the tolerability and safety of colchicine in routine practice is unknown. METHODS: Patients undergoing catheter ablation for AF who received colchicine after ablation were matched 1:1 to patients who did not by age, sex, and renal function. Recurrent AF was compared between groups categorically at 12 months and via propensity weighted Cox proportional hazards models with and without a 3-month blanking period. RESULTS: Overall, 180 patients (n = 90 colchicine and n = 90 matched controls) were followed for a median (Q1, Q3) of 10.3 (7.0, 12.0) months. Mean age was 65.3 ± 9.1 years, 33.9% were women, mean CHA2DS2-VASc score was 2.9 ± 1.5, and 51.1% had persistent AF. Most patients (70%) received colchicine 0.6 mg daily for a median of 30 days. In the colchicine group, 55 patients (61.1%) were receiving at least one known interacting medication with colchicine. After ablation, one patient required colchicine dose reduction and four patients required discontinuation. After adjusting for covariate imbalance using propensity weighting, no significant association between colchicine use and AF recurrence was identified (adjusted hazard ratio 0.94, 95% confidence interval [CI] 0.48-1.85; p = 0.853). No significant association was found between colchicine use and all-cause hospitalizations (adjusted odds ratio 0.74, 95% CI 0.28-1.96; p = 0.548). CONCLUSION: Despite the frequent presence of drug-drug interactions, a 30-day course of colchicine is well-tolerated after AF ablation; however, we did not observe any association between colchicine and lower rates of AF recurrence or hospitalization.

2023 HRS/APHRS/LAHRS guideline on cardiac physiologic pacing for the avoidance and mitigation of heart failure.

Cardiac physiologic pacing (CPP), encompassing cardiac resynchronization therapy (CRT) and conduction system pacing (CSP), has emerged as a pacing therapy strategy that may mitigate or prevent the development of heart failure (HF) in patients with ventricular dyssynchrony or pacing-induced cardiomyopathy. This clinical practice guideline is intended to provide guidance on indications for CRT for HF therapy and CPP in patients with pacemaker indications or HF, patient selection, pre-procedure evaluation and preparation, implant procedure management, follow-up evaluation and optimization of CPP response, and use in pediatric populations. Gaps in knowledge, pointing to new directions for future research, are also identified.

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.