Infarct size estimated from peak creatine kinase is reduced in patients using beta‐blockers at the onset of chest pain

摘要

AbstractIn 418 patients (median 67 years) with acute myocardial infarction (AMI) we examined if ongoing β‐blocker treatment at the onset of AMI (n= 63) had beneficial effects on infarct size as judged from peak creatine kinase (CKmax) activity. The study had an observational exposed/non‐exposed design where we investigated the possible association between β‐blocker treatment and CKmax. Both crude and adjusted effects were looked for, in the latter adjusting for the effect of confounders such as thrombolytic treatment and age during AMI.Crude effects: β‐blocker treatment significantly (p= 0.003) reduced CKmax, from 1171 U/1 to 790 U/1 (median values). In the 25 of patients with the largest infarcts, β‐blockers reduced the incidence of large infarcts by 61 (odds ratio = 0.39) (p= 0.015). Previous coronary heart disease reduced CKmax(p= 0.0001), whereas thrombolytic treatment significantly increase CKmax(p= 0.0001), probably due to reperfusion.Adjusted effects: β‐blocker treatment significantly reduced CKmax(p= 0.03), and reduced the incidence of large infarcts by 54 (odds ratio = 0.46).Thus, when adjusting for confounders, β‐blocker treatment at the onset of AMI reduced infarct size as well as the incidence of large infarcts. These observational results suggest real