Key result
Newer interventions in adult cardiac surgery rarely showed mortality benefits over older ones, with a median mortality effect size of 1.00 (IQR 0.54-1.30) across 73 meta-analyses.
Why the study?
It was unclear how often RCTs in adult cardiac surgery found significant mortality benefits for newer interventions vs older ones, whether effect estimates changed over time, and whether RCTs and observational studies yielded similar results.
Do newer interventions reduce mortality compared to older interventions in adult cardiac surgery?
Meta-Analysis (n=824)
Do newer interventions reduce mortality compared to older interventions in adult cardiac surgery?
Newer interventions in adult cardiac surgery rarely demonstrate mortality benefits over older interventions in randomized controlled trials, highlighting a discrepancy with observational studies which more frequently report benefits.
Answers are grounded in this paper and cite their sources.
Clinicians should require RCT mortality data before adopting newer interventions; challenges reliance on observational studies over randomized evidence.
OBJECTIVES: We aimed to assess how often randomized controlled trials (RCTs) in adult cardiac surgery found significant mortality benefits for newer interventions vs older ones, whether observed treatment effect estimates changed over time and whether RCTs and nonrandomized 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 1 RCT, with or without observational studies. Relative treatment effect sizes were evaluated overall, over time, and per study design. RESULTS: A total of 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 = .039). Four RCTs and six observational studies reached P < .005 favoring newer interventions. Two meta-analyses reached P < .005 favoring newer interventions. Effect size for experimental interventions relative to controls did not change over time overall (P = .64) or for RCTs (P = .30), and there was a trend for increase in observational studies (P = .027). In 34 meta-analyses with both RCTs (n = 95) and observational studies (n = 305), the median relative summary effect (summary effect in observational studies divided by summary effect in RCTs) was 0.87 (IQR, 0.55-1.29); meta-analysis of the relative summary effects yielded a summary of 0.93 (95% CI, 0.74-1.18). CONCLUSION: The vast majority of newer interventions had no mortality differences over older ones both overall and specifically in RCTs, while benefits for newer interventions were reported more frequently in observational studies.
No takes yet. Share an insight, caveat, or question.
Parish et al. (2025) conducted a meta-analysis in Adult cardiac surgery (n=824). Newer interventions vs. Older interventions was evaluated on Mortality (Median effect size 1.00). Newer interventions in adult cardiac surgery rarely showed mortality benefits over older ones, with a median mortality effect size of 1.00 (IQR 0.54-1.30) across 73 meta-analyses.
Synapse has enriched 10 related papers. Consider them for comparative context: