Minor myocardial damage and prognosis: are spontaneous and percutaneous coronary intervention-related events different?

Abstract

The relevance of the adverse prognostic implications of CK-MB elevation after percutaneous coronary intervention (PCI) remains controversial. Therefore, we compared the relationship between the level of postprocedural CK-MB elevation and 6-month mortality in patients undergoing PCI with the relationship between the level of spontaneous, non-PCI-related CK-MB elevation and 6-month mortality in patients with acute coronary syndromes (ACS) treated medically. In the PURSUIT trial, 5583 of 9461 patients who presented with a non-ST-elevation ACS did not undergo PCI or CABG and had at least 1 CK-MB sample collected during index-hospitalization. There was a gradual increase in 6-month mortality with higher CK-MB levels: 4.1%, 8.6%, 9.0%, 14.3%, 15.5% for CK-MB ratios 0 to 1, >1 to 3, >3 to 5, >5 to 10, and >10 times the upper limit of normal. A combined analysis in 8838 patients undergoing PCI in 5 large, clinical trials revealed a proportional relationship between postprocedural CK-MB levels (</= 48 hours after PCI) and 6-month mortality. In patients with CK-MB ratios 0 to 1, >1 to 3, >3 to 5, >5 to 10, and >10, the risk of death was 1.3%, 2.0%, 2.3%, 4.3%, and 7.4%, respectively. The absolute mortality rates were lower after procedure-related infarcts compared with spontaneous infarcts. Yet, the relative increase in 6-month mortality with each increase in peak CK-MB level was similar for PCI-related myocardial necrosis and spontaneous myocardial necrosis, as all tests for heterogeneity of the odds ratios were nonsignificant. The present analysis indicates that the adverse prognostic implications of periprocedural myocardial necrosis should be considered similar to the adverse consequences of spontaneous myocardial necrosis.