Publications

INTRODUCTION: Measurement of the spatial ventricular gradient (SVG), spatial QRST angles, and other vectorcardiographic measures of myocardial electrical heterogeneity have emerged as novel risk stratification methods for sudden cardiac death and other adverse cardiovascular events. Prior studies of normal limits of these measurements included primarily young, healthy, White volunteers, but normal limits in older patients are unknown. The influence of race and body mass index (BMI) on these measurements is also unclear.

METHODS: Normal 12-lead electrocardiograms (ECGs) from a single center were identified. Patients with abnormal cardiovascular, pulmonary, or renal history (assessed by International Classification of Disease [ICD-9/ICD-10] codes) or abnormal cardiovascular imaging were excluded. The SVG and QRST angles were measured and stratified by age, sex, and race. Multivariable linear regression was used to assess the influence of age, BMI, and heart rate (HR) on these measurements.

RESULTS: Among 3292 patients, observed ranges of SVG and QRST angles (peak and mean) differed significantly based on sex, age, and race. Sex differences attenuated with increasing age. Men tended to have larger SVG magnitude (60.4 [46.1-77.8] vs. 52.5 [41.3-65.8] mv*ms, p < .0001) and elevation, and more anterior/negative SVG azimuth (-14.8 [-25.1 to -4.3] vs. 1.3 [-9.8 to 10.5] deg, p < .0001) compared to women. Men also had wider QRST angles. Observed ranges varied significantly with BMI and HR. SVG and QRST angle measurements were robust to different filtering bandwidths and moderate fiducial point annotation errors, but were heavily affected by changes in baseline correction.

CONCLUSIONS: Age, sex, race, BMI, and HR significantly affect the range of SVG and QRST angles in patients with normal ECGs and no known cardiovascular disease, and should be accounted for in future studies. An online calculator for prediction of these "normal limits" given demographics is provided at https://bivectors.github.io/gehcalc/.

Cardiovascular disease (CVD) is the leading cause of death worldwide. Despite medical advances, patients with CVD experience high morbidity and mortality rates, affecting their quality of life and death. Among CVD conditions, palliative care has been studied mostly in patients with heart failure, where palliative care interventions have been associated with improvements in patient-centered outcomes, including quality of life, end-of-life care, and health care use. Although palliative care is now incorporated into the American Heart Association/American College of Cardiology/Heart Failure Society of America guidelines for heart failure, the role of palliative care for non-heart failure CVD remains uncertain. Across all causes of CVD, palliative care can play an important role in all domains of CVD care from initial diagnosis to terminal care. In addition to general cardiovascular palliative care practices applicable to all areas, disease-specific palliative care needs may warrant individualized palliative care models. In this review, we discuss the role of cardiovascular palliative care for ischemic heart disease, valvular disease, arrhythmias, peripheral artery disease, and adult congenital heart disease. Although there are multiple barriers to cardiovascular palliative care, we recommend a framework for studying and developing cardiovascular palliative care models to improve patient-centered goal-concordant care for this underserved patient population.

BACKGROUND: Remote monitoring of cardiac implantable electronic devices (CIEDs) offers practical and clinical benefits juxtaposed against burdens associated with high transmission volume.

METHODS: We identified patients receiving de novo pacemakers (PPMs) and implantable cardiac defibrillators (ICDs) at a single academic medical center (January 2016-December 2019) with at least 1 year of follow-up device care. We collected patient- and device-specific data at time of implant and assessed all remote and in-person interrogation reports for clinically actionable findings based on pre-specified criteria.

RESULTS: Among 963 patients (mean age of 71 (± 14) years, 37% female), 655 (68%) underwent PPM, and 308 (32%) underwent ICD implant. Median follow-up was 874 (627-1221) days, during which time patients underwent a mean of 13 (10-16) total interrogations; remote interrogations comprised 53% of all device evaluations; and of these, 96% were scheduled transmissions. Overall, 22% of all CIED interrogations yielded significant findings with a slightly higher rate in the PPM than in the ICD group (23% vs. 20%, p < 0.01). Only 8% of remote interrogations produced clinically meaningful results, compared with 38% of in-person ones. In adjusted models, routine, remote transmissions were least likely to be useful for both PPM and ICD patients (p < 0.001), whereas time from initial device implant was inversely associated with probability of obtaining a useful interrogation (p < 0.001).

CONCLUSIONS: Routine remote interrogations constitute the majority of device evaluations performed, but uncommonly identify clinically actionable findings.

BACKGROUND: Shared decision-making is mandated for patients receiving primary prevention implantable cardioverter defibrillators (ICDs). Less attention has been paid to generator exchange decisions, although at the time of generator exchange, patients' risk of sudden cardiac death, risk of procedural complications, quality of life, or prognosis may have changed. This study was designed to explore how patients make ICD generator exchange decisions.

METHODS: Emory Healthcare patients with primary prevention ICDs implanted from 2013 to 2021 were recruited to complete in-depth interviews exploring perspectives regarding generator exchanges. Interviews were conducted in 2021. Transcribed interviews were qualitatively coded using multilevel template analytic methods. To investigate benefit thresholds for pursuing generator exchanges, patients were presented standard-gamble type hypothetical scenarios where their ICD battery was depleted but their 5-year risk of sudden cardiac death at that time varied (10%, 5%, and 1%).

RESULTS: Fifty patients were interviewed; 18 had a prior generator exchange, 16 had received ICD therapy, and 17 had improved left ventricular ejection fraction. As sudden cardiac death risk decreased from 10% to 5% to 1%, the number of participants willing to undergo a generator exchange decreased from 48 to 42 to 33, respectively. Responses suggest that doctor's recommendations are likely to substantially impact patients' decision-making. Other drivers of decision-making included past experiences with ICD therapy and device implantation, as well as risk aversion. Therapeutic inertia and misconceptions about ICD therapy were common and represent substantive barriers to effective shared decision-making in this context.

CONCLUSIONS: Strong defaults may exist to continue therapy and exchange ICD generators. Updated risk stratification may facilitate shared decision-making and reduce generator exchanges in very low-risk patients, especially if these interventions are directed toward clinicians. Interventions targeting phenomena such as therapeutic inertia may be more impactful and warrant exploration in randomized trials.

BACKGROUND: Ablation for persistent atrial fibrillation (PsAF) has been performed for over 20 years, although success rates have remained modest. Several adjunctive lesion sets have been studied but none have become standard of practice. We sought to describe how the efficacy of ablation for PsAF has evolved in this time period with a focus on the effect of adjunctive ablation strategies.

METHODS: Databases were searched for prospective studies of PsAF ablation. We performed meta-regression and trial sequential analysis.

RESULTS: A total of 99 studies (15 424 patients) were included. Ablation for PsAF achieved the primary outcome (freedom of atrial fibrillation/atrial tachycardia rate at 12 months follow-up) in 48.2% (5% CI, 44.0-52.3). Meta-regression showed freedom from atrial arrhythmia at 12 months has improved over time, while procedure time and fluoroscopy time have significantly reduced. Through the use of cumulative meta-analyses and trial sequential analysis, we show that some ablation strategies may initially seem promising, but after several randomized controlled trials may be found to be ineffective. Trial sequential analysis showed that complex fractionated atrial electrogram ablation is ineffective and further study of this treatment would be futile, while posterior wall isolation currently does not have sufficient evidence for routine use in PsAF ablation.

CONCLUSIONS: Overall success rates from PsAF ablation and procedure/fluoroscopy times have improved over time. However, no adjunctive lesion set, in addition to pulmonary vein isolation, has been conclusively demonstrated to be beneficial. Through the use of trial sequential analysis, we highlight the importance of adequately powered randomized controlled trials, to avoid reaching premature conclusions, before widespread adoption of novel therapies.

BACKGROUND: The incidence and clinical impact of lead-related venous obstruction (LRVO) among patients with cardiovascular implantable electronic devices (CIEDs) is poorly defined.

OBJECTIVES: The objectives of this study were to determine the incidence of symptomatic LRVO after CIED implant; describe patterns in CIED extraction and revascularization; and quantify LRVO-related health care utilization based on each type of intervention.

METHODS: LRVO status was defined among Medicare beneficiaries after CIED implant from October 1, 2015, to December 31, 2020. Cumulative incidence functions of LRVO were estimated by Fine-Gray methods. LRVO predictors were identified using Cox regression. Incidence rates for LRVO-related health care visits were calculated with Poisson models.

RESULTS: Among 649,524 patients who underwent CIED implant, 28,214 developed LRVO, with 5.0% cumulative incidence at maximum follow-up of 5.2 years. Independent predictors of LRVO included CIEDs with >1 lead (HR: 1.09; 95% CI: 1.07-1.15), chronic kidney disease (HR: 1.17; 95% CI: 1.14-1.20), and malignancies (HR: 1.23; 95% CI: 1.20-1.27). Most patients with LRVO (85.2%) were managed conservatively. Among 4,186 (14.8%) patients undergoing intervention, 74.0% underwent CIED extraction and 26.0% percutaneous revascularization. Notably, 90% of the patients did not receive another CIED after extraction, with low use (2.2%) of leadless pacemakers. In adjusted models, extraction was associated with significant reductions in LRVO-related health care utilization (adjusted rate ratio: 0.58; 95% CI: 0.52-0.66) compared with conservative management.

CONCLUSIONS: In a large nationwide sample, the incidence of LRVO was substantial, affecting 1 of every 20 patients with CIEDs. Device extraction was the most common intervention and was associated with long-term reduction in recurrent health care utilization.