PhD Scientific Days 2022

Clinical Medicine VII. (Poster discussion will take place in the Aula during the Coffee Break)

The benefits of adding a defibrillator to cardiac resynchronization therapy - Systematic review and meta-analysis

Text of the abstract

Background: There is an long-standing debate whether cardiac resynchronisation therapy-defibrillation (CRT-D) is preferred over CRT-pacemaker (CRT-P). No randomised controlled trials have been designed to compare these treatments. However, several observational studies have been performed so far providing controversial results.

Methods: PubMed, CENTRAL and Embase until October 2021 were screened for studies comparing CRT-P and CRT-D, focusing on all-cause mortality, cardiovascular mortality, sudden cardiac death. Conference abstracts were excluded. Odds ratio with 95% confidence interval (CI) was calculated, data from the selected studies were pooled.Results were summarized by Forest plots.

Results: Altogether 20 observational retrospective studies (69 124 patients) were included (CRT-P: 37 461, CRT-D: 31 663). CRT-D was superior to CRT-P regarding all-cause mortality in multivariate analysis (aHR:0.79; 95% CI:0.69-0.88; p <0.01). Based on propensity matched studies (25 040 patients; 12 520 CRT-P, 12 520 CRT-D) CRT-D showed significantly better survival compared to CRT-P (HR:0.83; 95% CI:0.79-0.87; p<0.001). Three studies (47 846 patients, CRT-P: 27 344, CRT-D: 20 502) compared cardiovascular mortality between CRT-D and CRT-P. Univariate analysis showed a significantly lower rate of cardiovascular mortality in patients implanted with a CRT-D device compared to patients with a CRT-P device (HR:0.61; 95% CI:0.50-0.73; p=0.002). Five studies (6 434 patients. CRT-P:3 475, CRT-D:2 959) were analyzed for sudden cardiac death, CRT-D was superior in univariate analysis (HR:0.33; 95% CI:0.28-0.89; p=0.03).

Conclusion: Our meta-analysis demonstrated that patients with CRT-D had a lower risk of all-cause mortality compared to CRT-P based on those studies that used multivariate analysis and propensity score matching. Univariate analysis showed a significantly lower rate of cardiovascular- and sudden cardiac death in patients implanted with a CRT-D device compared to patients with a CRT-P. However, due to the heterogeneity of the articles coming from the selection bias of patients for CRT-D/CRT-P implantation, this question requires further analysis.