Effect of beta-blocker treatment in post-acute coronary syndrome patients in cardiac rehabilitation

Introduction: The use of beta blockers (BB) in patients with left ventricular ejection fraction (LVEF) >40% after acute coronary syndrome (ACS) is not completely established. The REBOOT5 trial will attempt to clarify the need to maintain BB prescription in these patients. Cardiac rehabilitation (CR) reduces hospitalizations and cardiovascular mortality in patients with ACS. However, the use of BB could limit the beneficial effects of exercise in patients with cardiovascular disease. Material and method: As a sample we have used 53 patients with a diagnosis of ACS and with LVEF >40% at discharge. All of them completed a CR program and performed a cardiopulmonary exercise test (CPET) before CR and at the end of the program. Patients were divided into 3 groups according to BB treatment (with treatment, with progressive reduction of treatment and without treatment), and SPSS software was used for statistical analyses. Categorical variables were expressed using absolute values and percentages and continuous variables using the mean ± standard deviation. Results with a value of P <0.05 were considered significant. Results: The most interesting results come from the analysis of the changes in functional capacity between the stress tests before and after CR, especially in both groups with dose reduction and without BB. Considering the metabolic equivalent task (MET) to evaluate these variations, patients with BB reduction showed the greatest increases in both absolute and percentage values. Furthermore, if we consider VO2max, greater improvements were observed in the group without BB. Conclusion: In conclusion, in our study of patients with ACS and LVEF >40% who underwent a CR program, patients without BB treatment or with BB reduction during CR showed greater improvements in functional capacity parameters, both in MET and in VO2max.