P4630Prognostic impact of previous Beta-blocker use in STEMI patients

Abstract

Abstract Introduction Current guidelines support the use of beta-blockers (βB) in patients with Coronary Artery Disease, especially after a Myocardial Infarction (MI). This use is sustained by their ability to block adrenergic hyperstimulation, reducing the potential for arrythmias, myocardial oxygen consumption and infarct extension. However, questions have been raised regarding the impact βB therapy in patients admitted for ST elevation Myocardial Infarction (STEMI). Methods The authors present a retrospective, descriptive and correlational study including all patients admitted for STEMI in a country's Cardiology Departments between the 1st of October 2010 and the 8th of January 2019. A 1-year (1y) follow-up was made through registry consultation and phone call by a Cardiologist. Baseline demographic and clinical characteristics of patients previously medicated with βB (pre- βB) were compared to patients not medicated with βB. The authors performed a univariate and multivariate statistical analysis of in-hospital mortality, as well as 1y mortality and re-admission rate, using SPSS 24,0. Results A total of 7818 patients were included, 1931 (24,7%) of which 1931 (24,7%) were female, with a mean age of 64±14 years. In the studied sample, 1109 patients (14,2%) were previously medicated with βB, which was more common in women (18,1 vs. 12,8%) and patients over 65-years old (16,9% vs. 11,4%). βB were also more prescribed in patients with hypertension, diabetes, dyslipidaemia, previous MI, previous stroke or peripheral atherosclerosis, and renal failure. This group of patients was more frequently medicated with anti-platelets, anti-hypertensives, statins and diuretics (p<0,001). Additionally, they presented more frequently with Left Bundle Branch Block, Atrial fibrillation, Killip-Kimball class >1 and BNP >400 (p<0,001), and had significantly higher rates of ventricular systolic disfunction (p=0,003). These patients were also more commonly diagnosed with multivessel disease (p<0,001), but no differences could be identified regarding success of revascularization. During hospital stay, no significant divergences were found regarding incidence of shock, mechanical complications and AV block, but a higher rate of haemorrhage and transfusion was objectified (p<0,001). Regarding outcomes, on univariate analysis, pre-βB was a strong predictor of higher 1-year mortality (p=0,049) and 1-year readmission (both global and cardiovascular, with p=0,049 and p=0,033, respectively). On multivariate statistical analysis however, pre-βB showed to be a strong independent predictor of lower in-hospital mortality (p=0,023) with differences between groups who suspended and ditn't suspend βB at admission, but had no significant impact on 1-year outcomes. Conclusion In the present study, previous βB therapy showed to have an independent positive impact on in-hospital mortality, but not on 1-year outcomes.