Background: Creatine kinase (CK)-MB elevation after percutaneous coronary intervention (PCI) has been associated with subsequent cardiac death. The patients at risk, the timing of risk, and potential treatment implications are uncertain.
Methods and results: Eight thousand, four hundred nine consecutive non- acute myocardial infarction patients with successful PCI and no emergency surgery or Q-wave myocardial infarction were followed for 38+/-25 months; 1446 (17.2%) had post-PCI CK-MB above normal on routine ascertainment. Patients were prospectively stratified into those with CK-MB 1 to 5x or CK-MB >5x normal. No patient with CK-MB 1 to 5x normal died during the first week after PCI, and excess risk of early death for patients with CK-MB elevation occurred primarily in the first 3 to 4 months. The actuarial 4-month risk of death was 8.9%, 1.9%, and 1.2% for patients with CK-MB >5x, CK-MB 1 to 5x, and CK-MB < or =1x normal (P<0.001). Death within 4 months was independently correlated with the degree of CK-MB elevation, creatinine > or =2 mg%, post-PCI C-reactive protein, low ejection fraction, age, and congestive heart failure class (P<0.01 for all). In a matched subset analysis, incomplete revascularization (P<0.001), congestive heart failure class (P=0.005), and no statin treatment at hospital discharge (P=0.009) were associated with death.
Conclusions: Patients with CK-MB elevation after PCI are at excess risk of death for 3 to 4 months, although prolonging hospitalization for CK-MB 1 to 5x is unlikely to modify risk. CK-MB >5x normal, incomplete revascularization, elevated C-reactive protein, heart failure, the elderly, and hospital discharge without on statin therapy increases risk. Several of these factors suggest that inflammation may play a part in the excess risk of death.