Long-term clinical outcomes after upgrade to resynchronization therapy: A propensity score–matched analysis

BACKGROUND: Upgrade to cardiac resynchronization therapy (CRT) is common in Europe, despite little and conflicting evidence. OBJECTIVE: To compare long-term clinical outcomes in a cohort of patients receiving de novo or upgrade to CRT. METHODS: Single-center retrospective study of 295 consecutive patients submitted to CRT implantation between 2007 and 2018. Upgraded and de novo patients complying with a dedicated follow-up protocol were compared in terms of clinical (NYHA class improvement without major adverse cardiac events [MACE] in the first year of follow-up) and echocardiographic (left ventricle end-systolic volume reduction of >15% during the first year) response. RESULTS: No differences in the rate of clinical (59.3% vs 62.6%, P = .765) or echocardiographic response (72.2% vs 71.9%, P = .970) between groups were observed. Device-related complications were also comparable between groups (8.9% vs 8.4%, P = .892). Occurrence of MACE and all-cause mortality were analyzed over a median follow-up of 3 (interquartile range 1–6) years: MACE occurred less frequently in the de novo group (hazard ratio [HR]: 0.55, 95% confidence interval [CI]: 0.34–0.90, P = .018), but all-cause mortality was similar among groups (HR: 0.87, 95% CI: 0.46–1.64, P = .684). Propensity score–matching analysis was performed to adjust for possible confounder variables. In the propensity-matched samples, all-cause mortality (HR: 1.26, 95% CI: 0.56–2.77, P = .557) and MACE (HR: 0.84, 95% CI: 0.46–1.54, P = .574) were comparable between upgrade and de novo patients. CONCLUSION: Survival after upgrade to resynchronization therapy was comparable to de novo implants. Additionally, clinical and echocardiographic response to CRT in upgraded patients were similar to de novo patients.