Beta-blockers after STEMI: prognostic impact and predictors of adherence, results from the real-world FAST-STEMI registry
Authors: Ravetti E , Giacobbe F , Annone U , Giannino G , Di Vita U , Troncone M , Morena A , Carmagnola L , Nebiolo M , De Filippo O , Bruno F , Gaido L , D'ascenzo F , Giammaria M , De Ferrari G M 
Published: November 2023

Abstract

Background
The impact of beta-blocker therapy on cardiovascular outcomes after ST-elevation acute myocardial infarction (STEMI) is debated. Adherence to beta-blockers after acute myocardial infarction and effect on long term cardiovascular outcomes are also fields with significant knowledge gaps.

Purpose
To identify predictors of lower compliance to beta-blocker therapy and estimate its impact on cardiovascular outcomes and mortality during the first year of follow-up after the index event.

Methods
We evaluated real-world adherence to the most common cardiovascular drugs by comparing the number of tablets bought in pharmacies to the expected number of tablets needed at 1 year and at the final follow-up. A total of 6043 patients with STEMI were enrolled in the FAST-STEMI registry from 2012 to 2017 and followed up for 4.7±1.6 years. 299 patients with intraprocedural and intrahospital deaths were excluded. The main outcomes evaluated were all-cause death, cardiovascular death, myocardial infarction, major and minor bleeding events, and ischemic stroke. The best compliance cut-off was found by ROC curve analysis with Youden index; Kaplan Meier and Cox proportional hazard models were performed to evaluate cumulative event rates of mortality at follow-up. Predictors of lower adherence were evaluated in univariate and multivariate analyses with logistic regression.

Results
A total of 4992 patients with beta-blockers prescription at discharge were enrolled: mean age was 64±12.3 years old, 76% were male, mean ejection fraction was 49±8.8%. Mean adherence to beta-blockers was 95,8% (IQR 82.2-100). After univariate and multivariate analyses, age over 75 years old (OR 0.76, 95%CI 0.63-0.91) and previous coronary artery disease (OR 0.62, 95%CI 0.44-0.87) resulted as predictors of lower compliance, whereas concomitant ACEi/ARB prescription at discharge was a predictor of good adherence (OR 1.23, 95%CI 1.04-1.46). Adherence to beta-blockers higher than 65.68% (identified as best cut-off at Youden’s analysis) was related to a lower cardiovascular (0.65% vs 1.49%, p 0.009) and all-cause mortality (1.98% vs 4.48%, p &lt;0.001).
At multivariate analysis, adherence to beta-blockers was significantly associated with lower cardiovascular mortality (HR 0.40, 95%CI 0.20-0.81, p 0.01) as well as EF &gt;50% (HR 0.30, 95%CI 0.14-0.63, p 0.002), while age over 75 years old (HR 4.72, 95%CI 2.23-9.98, p &lt;0.001) and history of atrial fibrillation (HR 2.63, 95%CI 1.02-6.80, p 0.04) were associated with a higher risk of cardiovascular death.
Finally, optimal adherence to beta-blockers did not reduce the number of myocardial infarctions, strokes, or bleeding events.

Conclusions
In our large real-world registry, optimal adherence to beta-blockers after STEMI was associated with a reduction in both cardiovascular and all-cause mortality. Older age and previous coronary artery disease resulted as predictors of poor compliance to beta-blocker therapy.Kaplan Meier on all-cause and CV deathMultivariate analysis on CV death