A study evaluated 14,542 patients from the International Survey of Acute Coronary Syndromes (ISACS-Archives), specifically the ISACS-TC registry (data from 41 centers in 12 European countries) and the EMMACE-3X registry (data from 47 hospitals in England). Eligible patients had clinically confirmed ACS and were excluded if they had a prior history of ASCVD (history of stroke, angina, myocardial infarction, heart failure, prior revascularization, or peripheral arterial disease). Patient characteristics were stratified according to treatment group of statin users versus nonstatin users. The key outcome measure was the prevalence of AHF (based on Killip class) on admission for ACS as the index presentation of ASCVD. Other outcomes included the association of AHF with all-cause mortality at 30 days from admission and the role of ST-segment elevation myocardial infarction (STEMI) as a predictor of outcome. The 10-year risk of ASCVD was calculated for each patient using the Pooled Cohort Equations with a cutoff for increased level of ASCVD risk of 10%. Potential confounders were analyzed using inverse probability of treatment weighting on the basis of propensity scores.
A total of 1,824 (12.6%) patients reported prior use of statins. Statin users were more often former smokers, had higher body mass index, and more frequently had diabetes, hypertension, hypercholesterolemia, chronic kidney disease, prescribed concomitant evidence-based medications (aspirin, angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, and beta-blockers), and had a higher predicted 10-year ASCVD risk compared to nonstatin users. After adjustment for inverse probability of treatment weighting, no statistically significant or clinically relevant standardized differences were observed between statin users and nonusers.
Previous statin use was associated with significantly decreased prevalence of AHF at the time of ACS admission (absolute difference 4.3%; relative risk [RR], 0.72; 95% confidence interval [CI], 0.62-0.83). The effect of statins was consistent despite age (interaction p = 0.27) and gender (interaction p = 0.22). Notably, statin benefits were observed in patients with higher ASCVD risk (RR, 0.73; 95% CI, 0.63-0.85), but the same benefit was not seen in the lower-risk group (RR, 0.85; 95% CI, 0.6-1.2). Statin use was associated with a more pronounced decreased risk of presenting with AHF for those with diabetes or current smokers compared to their counterparts (interaction p = 0.03). A lower risk of 30-day mortality was observed for statin users (15.5%) compared with statin nonusers (20.7%; RR, 0.71; 95% CI, 0.5-0.99), but only for patients presenting with AHF on hospital admission. Prior statin use was associated with a lower risk of STEMI presentation and patients presenting with STEMI were more likely to have AHF on hospital admission for ACS.
Treatment with statins reduces the risk of AHF events and early mortality from AHF events in adults presenting with ACS as the first manifestation of CVD.