Cardioprotective effect of prior beta-blocker therapy in reducing creatine kinase-MB elevation after coronary intervention: benefit is extended to improvement in intermediate-term survival.

BACKGROUND Both retrospective studies and prospective randomized trials have shown that beta-blockers improve survival and reduce the risk of reinfarction in patients with myocardial infarction. To evaluate whether beta-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 beta-blocker therapy and its effect on intermediate-term ( approximately 1 year) survival. METHODS AND RESULTS We prospectively analyzed 1675 consecutive patients undergoing coronary intervention; of these patients, 643 (38.4%) were on beta-blocker therapy before the intervention. The incidence of CK-MB elevation after coronary intervention was 13.2% in patients on beta-blocker therapy before intervention and 22.1% in patients who were not on beta-blockers (P<0.001). Patients with prior beta-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 beta-blockers (P<0.001). Multiple linear regression analysis revealed prior beta-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 beta-blocker therapy before intervention had lower mortality rates compared with those not on beta-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 beta-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.