Background - Both retrospective studies and prospective randomized trials have shown that β-blockers improve survival and reduce the risk of reinfarction in patients with myocardial infarction. To evaluate whether β- blockers exert similar protective benefits during and after coronary intervention, we studied the incidence of postprocedure creatine kinase (CK)- MB elevation in patients with or without prior β-blocker therapy and its effect on intermediate-term (≃ 1 year) survival. Methods and Results - We prospectively analyzed 1675 consecutive patients undergoing coronary intervention; of these patients, 643 (38.4%) were on β-blocker therapy before the intervention. The incidence of CK-MB elevation after coronary intervention was 13.2% in patients on β-blocker therapy before intervention and 22.1% in patients who were not on β-blockers (P<0.001). Patients with prior β-blocker therapy had lower persistent/recurrent postprocedure chest pain and lower preprocedure and postprocedure heart rates and mean blood pressures compared with patients who were not on β-blockers (P<0.001). Multiple linear regression analysis revealed prior β-blocker therapy as the sole independent factor for lower CK-MB release after coronary intervention. During intermediate-term follow-up at 15±3 months, patients on β-blocker therapy before intervention had lower mortality rates compared with those not on β-blockers (0.78% versus 1.96%; P=0.04), although the benefit was independent of the reduction in CK-MB release. Conclusions - Our nonrandomized, prospective analysis suggests that prior β-blocker therapy has a cardioprotective effect in limiting CK-MB release after coronary intervention and that it is associated with a lower mortality at intermediate-term follow-up.
- Creatine kinase
- Myocardial infarction