Abstract
• Positive outcomes in intensive lipid-lowering trials are mainly driven by nonfatal MI.
• Excluding nonfatal MI, intensive lipid-lowering trials show no significant benefit.
• Guidelines may overestimate the benefits of intensive lipid-lowering therapy.
Background: To identify pharmacological randomized controlled trials (RCTs) with "positive" outcomes driven by nonfatal myocardial infarction (MI) reductions and assess related guideline recommendations.
Methods: RCTs published between 2000 and 2024 focusing on mortality and nonfatal MI were identified through searches in PubMed and Web of Science. Citation tracking was used to find trials referenced in clinical guidelines. The levels of guideline recommendations based on the supporting trials were summarized. The impact of nonfatal MI on composite outcomes was assessed by using the leave-one-out method.
Results: Of 21,005 records, 6 RCTs demonstrating positive outcomes due to nonfatal MI reduction were cited in current guidelines, including anti-thrombotic (3), intensive lipid-lowering (2), and anti-inflammatory (1) therapies. Intensive lipid-lowering trials (IMPROVE-IT, FOURIER; totaling 60 recommendations across 17 guidelines) were more frequently recommended in guidelines: 45% Class I, 33.3% Class IIa, and 21.7% Class IIb. Anti-thrombotic and anti-inflammatory trials had no Class I recommendations and higher Class IIb recommendations (66.7% and 100%). A meta-analysis including major intensive lipid-lowering RCTs on top of maximally tolerated statins (IMPROVE-IT, FOURIER, and ODYSSEY OUTCOMES) revealed no statistical difference in primary composite outcome after removing nonfatal MI events (relative risk 0.94, 95% confidence interval: 0.88-1.01).
Conclusion: In contemporary pharmacological RCTs with positive composite outcome driven by nonfatal MI reduction, intensive lipid-lowering trials are more frequently received strong guideline recommendations. This analysis underscores the need to evaluate whether these recommendations fully reflect the clinical significance of the observed benefits.