Objective: We sought to evaluate the impact of intermediate creatine kinase-myocardial band isoenzyme (CK-MB) elevation on late clinical outcomes in patients undergoing successful stent implantation in native coronary arteries.
Background: Elevations of CK-MB after percutaneous coronary interventions are frequent. An association between high level of CK-MB elevation (>5 times normal) and late mortality after balloon and new device angioplasty has been reported previously. However, significant controversy remains on the long-term clinical importance of lower CK-MB elevations (one to five times normal) after percutaneous coronary revascularization. Moreover, the incidence and prognostic importance of cardiac enzyme elevation after coronary stenting have not been well established.
Methods: Prospectively collected data from 900 consecutive patients (1,213 lesions) undergoing successful stenting in native vessels were analyzed. Based on the CK-MB levels after coronary stenting, patients were classified into three groups: normal group 1 (n = 585), elevation of >1 to 5 times normal group 2 (n = 238) and elevation of >5 times normal group 3 (n = 77).
Results: Patients in group 3 had more in-hospital recurrent ischemia (p = 0.001) and pulmonary edema (p = 0.01) than patients in groups 1 and 2. Long-term clinical end points were similar between groups 1 and 2. However, patients in group 3 had an increased incidence of late mortality compared with patients in groups 2 and 1 (6.9%, 1.2% and 1.7%, respectively, p = 0.01). Multivariate analysis showed that patients with CK-MB >5 times normal after coronary stenting had an increased risk of major adverse clinical events (relative risk: 1.70, p < 0.05) and death (relative risk: 3.25, p < 0.05) that was not observed in patients with lower CK-MB rise.
Conclusions: Patients with CK-MB elevation >5 times normal had higher late mortality and more unfavorable event-free survival than those patients with normal or lower CK-MB rise after coronary stenting. While intermediate CK-MB elevation (>1 to 5 times normal) is frequent after coronary stenting (26%), this was not associated with an increased risk of late mortality or major adverse clinical events.