Are there mortality improvements with newer interventions in adult cardiac surgery? Evidence from 73 meta-analyses

ABSTRACT Background In the last two decades, many new interventions have been introduced with the ultimate goal of improving overall postoperative outcomes after cardiac operations in adults. We aimed to assess how often randomized controlled trials (RCTs) in adult cardiac surgery found significant mortality benefits for newer interventions versus older ones, whether observed treatment effect estimates changed over time and whether RCTs and non-randomized observational studies gave similar results. Methods We searched journals likely to publish systematic reviews on adult cardiac surgery for meta-analyses of mortality outcomes and that included at least one RCT, with or without observational studies. Relative treatment effect sizes were evaluated overall, over time, and per study design. Results 73 meta-analysis comparisons (824 study outcomes on mortality, 519 from RCTs, 305 from observational studies) were eligible. The median mortality effect size was 1.00, IQR 0.54-1.30 (1.00 among RCTs, 0.91 among observational studies, p=0.039). 4 RCTs and 6 observational studies reached pConclusions The vast majority of newer interventions had no mortality differences over older ones both overall and in RCTs in particular, while benefits for newer interventions were reported more frequently in observational studies.