Heart rhythm, 7 1 2026, Pages S1547-5271(26)00019-6 Effectiveness of Cardiac Resynchronization Therapy in Adult Congenital Heart Disease: A Meta-Analysis of Biventricular and Conduction System Pacing Outcomes. Zwaenepoel BAC, Neijenhuis RML, Veldtman G, Blom NA, Jukema JW, Jongbloed MRM, Schoones JW, Beeres SLMA, Egorova AD
Adult congenital heart disease (ACHD) patients often develop heart failure (HF). Cardiac resynchronization therapy (CRT) may provide benefit, but evidence is limited to observational studies and guidelines are extrapolated from acquired HF. To systematically evaluate the effects of CRT in ACHD, including both biventricular (BiV) and conduction system pacing (CSP) strategies, on electrocardiographic, functional, and clinical outcomes. We conducted a systematic review and meta-analysis following PRISMA guidelines (PROSPERO CRD420251036152). PubMed, Embase, Web of Science, CINAHL, and Cochrane were searched to February 2025. Primary outcomes were changes in QRS duration, systemic ventricular function (SVF), and New York Heart Association (NYHA) class; secondary outcomes were HF hospitalizations and all-cause mortality. Twenty-five studies (n=796; 723 BiV, 73 CSP) were included. CRT was associated with significant QRS duration reduction (-23.1 ms, 95% CI -31.6 to -14.7), SVF improvement (+7.8%, 5.9-9.6), and NYHA class reduction (-0.9, -1.2 to -0.5). Benefits extended to systemic right ventricle (sRV) patients (QRS -27.7 ms, SVF +8.5%, NYHA -1.0). Pooled incidence rates of HF hospitalization and mortality were 4.3 and 3.2 per 100 patient-years, respectively. Early data suggest CSP achieves comparable QRS narrowing to BiV, though long-term outcomes remain scarce. CRT in ACHD is associated with significant improvements in electrocardiographic, functional, and clinical outcomes, including sRV patients. While most evidence pertains to BiV, early reports on CSP are encouraging. Prospective, phenotype-specific studies with standardized outcomes are needed to optimize patient selection and pacing strategies.
