Impact of Cardiac Resynchronization Therapy on Heart Transplant-Free Survival in Pediatric and Congenital Heart Disease Patients

Abstract

Background - Cardiac resynchronization therapy (CRT) studies in pediatric and/or congenital heart disease (CHD) patients have shown an improvement in ejection fraction and heart failure symptoms. However, a survival benefit of CRT in this population has not been established. This study aimed to evaluate the impact of CRT upon heart transplant-free survival in pediatric and CHD patients, using a propensity score-matched analysis. Methods - This single-center study compared CRT patients (implant date 2004-2017) and controls, matched by 1:1 propensity-score matching (PSM) using 21 comprehensive baseline indices for risk stratification. CRT patients were <21 years or had CHD; had systemic ventricular ejection fraction <;45%; symptomatic heart failure; and had significant electrical dyssynchrony, all prior to CRT implant. Controls were screened from non-selective imaging and ECG databases. Controls were retrospectively enrolled when they achieved the same inclusion criteria at an outpatient clinical encounter, within the same time period. Results - Of 133 patients who received CRT during the study period, 84 met all study inclusion criteria. 133 controls met all criteria at an outpatient encounter. Following PSM, 63 matched CRT-control pairs were identified with no significant difference between groups across all baseline indices. Heart transplant or death occurred in 12 (19%) PSM-CRT subjects and 37 (59%) PSM-controls with a median follow-up of 2.7 years (quartiles 0.8-6.1 years). CRT was associated with markedly reduced risk of heart transplant or death (hazard ratio 0.24 [95% CI 0.12-0.46], p<0.001). There was no CRT procedural mortality and one system infection at 54 months post-implant. Conclusions - In pediatric and CHD patients with symptomatic systolic heart failure and electrical dyssynchrony, CRT was associated with improved heart transplant-free survival.

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

“…Patients with a systemic LV have shown the greatest response to CRT in comparison to systemic RV and single-ventricle patients. 401,403,411 While the majority of studies of CHD and CRT have found improvements in EF, clinical status, and QRS duration, only recently has a survival benefit been shown. 401 Additional considerations for use of CRT in these populations include the need to normalize QRS duration for age by the use of z scores 422 ; the need for varied approaches to device implantation based on size, access, and anatomy; and the potential for disadvantages of size to outweigh procedural benefits in the smallest of patients.…”

“…CRT has been used in these patients with varying degrees of success. Patients with a systemic LV have shown the greatest response to CRT in comparison to systemic RV and single‐ventricle patients 401,403,411 . While the majority of studies of CHD and CRT have found improvements in EF, clinical status, and QRS duration, only recently has a survival benefit been shown 401 …”

Conduction system pacing in pediatric and congenital heart disease

“…Pediatric and CHD patients are at risk of cardiomyopathy either secondary to long-term pacing or cardiac dyssynchrony, secondary to existing conventional (single-site, non-CSP) pacing or inherent conduction disease. Traditional biventricular pacing (CRT) has been used with some success in these scenarios (Chubb et al, 2020), but there is growing interest in CSP both to treat and prevent this issue.…”

Classic-Pattern Dyssynchrony Is Associated with Outcome in Patients with Fontan Circulation

“…Additionally, the identification of echocardiographic parameters that may identify Fontan patients who would benefit from CRT is paramount to gaining the maximal benefit from this therapy. A recent publication on outcome on CRT treated patients with congenital heart disease, including 9 patients with UVH and propensity matched controls shows promising effect of CRT treatment, leading to improved transplant-free survival [40].…”