American Journal of Cardiovascular Drugs | 2021
Meta-Analysis Comparing the Safety and Efficacy of Dual Versus Single Antiplatelet Therapy After Transcatheter Aortic Valve Implantation
Abstract
Current expert consensus guidelines recommend dual antiplatelet therapy (DAPT) with aspirin and clopidogrel for 3–6 months after transcatheter aortic valve implantation (TAVI) [1]. This recommendation, however, is based primarily on data from small observational studies, which suggest improved mortality with DAPT [2]. The recent Antiplatelet Therapy for Patients Undergoing Transcatheter Aortic Valve Implantation (POPular-TAVI) trial highlighted that this empirical DAPT regimen may cause increased risk of bleeding without any significant prevention of ischemic events compared with single antiplatelet therapy (SAPT) using only aspirin [3]. Previous meta-analyses have yielded conflicted findings owing to the inclusion of observational studies, which can confound results [2, 4, 5]. The availability of sufficient trial data warrants an updated meta-analysis of randomized clinical trials (RCTs). Additionally, trials are often powered to study composite outcomes, and metaanalysis can enable appraisal of individual outcomes. PubMed and Scopus were searched from inception until 1 September 2020 to identify relevant studies, using the following MeSH terms: “transcatheter aortic valve implantation,” “TAVI,” “transcatheter aortic valve replacement,” “TAVR,” “dual antiplatelet therapy,” “single antiplatelet therapy,” “aspirin,” “clopidogrel,” “antiplatelet,” “antithrombotic,” and “P2Y receptor antagonist.” Studies were included if they (1) were RCTs, (2) included patients undergoing TAVI, and (3) evaluated direct comparison between DAPT (aspirin and clopidogrel) and SAPT (only aspirin) after TAVI. Outcomes of interest included (1) all-cause mortality, (2) disabling stroke, (3) myocardial infarction, (4) major bleeding, and (5) life-threatening bleeding. The two regimens were compared for long-term outcomes (3–12 months), which were independently pooled from each RCT. For each outcome, the pooled risk ratio (RR) and 95% confidence interval (CI) were calculated using a random-effects model, and were adjusted by participant-months to account for any differences in follow-up duration. A p value < 0.05 was considered significant. Our initial search yielded 527 potential studies. After exclusions, three studies including 966 participants (485 DAPT; 481 SAPT) were included for analysis.[3, 6, 7] Study, procedural characteristics, and risk of bias are shown in Table 1. Pooled analysis revealed no significant difference in mortality (RR 0.98 [0.60–1.61]; p = 0.94; I2 = 0%), disabling stroke (RR 0.77 [0.29–2.07]; p = 0.61; I2 = 0%), myocardial infarction (RR 1.99 [0.71–5.57]; p = 0.19; I2 = 0%), and life-threatening bleeding (RR 1.58 [0.62–4.03]; p = 0.34; I2 = 21%) comparing DAPT versus SAPT. However, an increased risk of major bleeding was observed in DAPT (RR 2.61 [1.35–5.03]; p < 0.01; I2 = 0%) compared with SAPT (Fig. 1). The results of the current meta-analysis suggest no superiority of DAPT (aspirin plus clopidogrel) over SAPT (only aspirin) in preventing mortality, disabling stroke, myocardial infarction, or life-threatening bleeding beyond 3 months in patients post-TAVI. However, DAPT exposes an additional 1 per 25 patients (number needed to harm) to the risk of major bleeding, when compared with SAPT. Major bleeding includes a drop in hemoglobin level of at least 3.0 g/ * Izza Shahid [email protected]