Background: The association between chronic beta-blocker treatment and haemodynamics at admission in patients with ST-segment elevation myocardial infarction treated by primary percutaneous coronary intervention is not well studied. We investigated the impact of chronic beta-blocker treatment on the risk of cardiogenic shock and pre-shock at admission in patients with ST-segment elevation myocardial infarction treated by primary percutaneous coronary intervention.
Methods and results: A total of 4907 patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention were included in the study. A total of 1148 patients (23.3%) were on chronic beta-blocker treatment. Cardiogenic shock was observed in 264 patients (5.3%). Pre-shock was defined as a shock index (the ratio of heart rate and systolic blood pressure) of 0.7 or greater, and was observed in 1022 patients (20.8%). The risk of cardiogenic shock in patients with chronic beta-blocker treatment was not increased (adjusted hazard ratio (HR) 0.97, 95% confidence interval (CI) 0.65-1.46, P=0.90). Chronic beta-blocker treatment was also not associated with an increased risk of pre-shock (adjusted HR 0.86, 95% CI 0.68-1.07, P=0.19). Also after propensity score matched analysis, there was no increased risk of cardiogenic shock or pre-shock in patients with chronic beta-blocker treatment (respectively HR 0.97, 95% CI 0.61-1.51, P=0.88 and HR 0.82, 95% CI 0.65-1.06, P=0.12).
Conclusion: In ST-segment elevation myocardial infarction, chronic beta-blocker treatment is not associated with an increased risk of cardiogenic shock or pre-shock.
Keywords: Myocardial infarction; beta-blocker; cardiogenic shock; shock index; survival.