Cardioprotective Effect of Prior b-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 b-blockers improve survival and reduce the risk of reinfarction in patients with myocardial infarction. To evaluate whether b-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 b-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 b-blocker therapy before the intervention. The incidence of CK-MB elevation after coronary intervention was 13.2 % in patients on b-blocker therapy before intervention and 22.1 % in patients who were not on b-blockers (P,0.001). Patients with prior b-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 b-blockers (P,0.001). Multiple linear regression analysis revealed prior b-blocker therapy as the sole independent factor for lower CK-MB release after coronary intervention. During intermediate-term follow-up at 1563 months, patients on b-blocker therapy before intervention had lower mortality rates compared with those not on b-blockers (0.78 % versus 1.96%; P50.04), although the benefit was independent of the reduction in CK-MB release. Conclusions—Our nonrandomized, prospective analysis suggests that prior b-blocker therapy has a cardioprotective effec