Creatine Kinase-MB elevation after coronary intervention correlates with diffuse atherosclerosis, and low-to-medium level elevation has a benign clinical course - Implications for early discharge after coronary intervention

OBJECTIVES The study evaluated the incidence and predictors of creatine kinase-MB isoenzyme (CK-MB) elevation after successful coronary intervention using current devices, and assessed the influence on in-hospital course and midterm survival. BACKGROUND The CK-MB elevation after coronary intervention predominantly using balloon angioplasty correlates with late cardiac events of myocardial infarction (MI) and death. Whether CK-MB elevation after nonballoon devices is associated with an adverse short and midterm prognosis is unknown. METHODS The incidence and predictors of CK-MB elevation after coronary intervention were prospectively studied in 1,675 consecutive patients and were followed for in-hospital events and survival. RESULTS CK-MB elevation was detected in 313 patients (18.7%), with 1-3 X in 12.8%, 3-5 x in 3.5% and >5x normal in 2.4% of patients. Procedural complications or electrocardiogram changes occurred in only 49% of the CK-MB-eIevation cases; CK-MB elevation was more common after nonballoon devices (19.5% vs. 11.5% after percutaneous transluminal coronary angioplasty; p < 0.01). Predictors of CK-MB elevation on multivariate analysis were diffuse coronary disease (p = 0.02), systemic atherosclerosis (p = 0.002), stent use (p = 0.04) and absence of beta-blocker therapy (p = 0.001). Adverse in-hospital cardiac events were more frequent in patients with >5X CK-MB elevation, with no significant difference between 1-5X CK-MB elevation versus normal CK-MB group. During a mean follow-up of 13 +/- 3 months, the incidence of death in the CK-MB-elevation group was 1.6% versus 1.3% in the normal CK-MB group (p = NS). CONCLUSIONS The CK-MB elevation after coronary intervention was observed even in the absence of discernible procedural complications and was more common in patients with diffuse atherosclerosis. In-hospital clinical events requiring prolonged monitoring were higher in >5X CK-MB-elevation patients only. Midterm survival of CK-MB-elevation patients was similar to those with normal CK-MB. Our prospective analysis shows a lack of adverse in-hospital cardiac events and suggests that early discharge of stable 1-5 x normal CK-MB-elevation patients after successful coronary intervention is safe. (J Am Coll Cardiol 1999;34: 663-71) (C) 1999 by the American College of Cardiology.