Revisiting the culprit lesion in non–Q-wave myocardial infarction: Results from the VANQWISH trial angiographic core laboratory

Objectives We sought to determine the underlying coronary anatomy and characterize the culprit lesion after non–Q-wave myocardial infarction (NQWMI). Background Although the culprit lesion and infarct-related artery often are easily identified with coronary angiography after Q-wave MI, the culprit lesion after NQWMI has not been well characterized. Small retrospective studies have suggested that the absence of Q-waves on an electrocardiogram is due to incomplete occlusion of the infarct-related artery. Methods Coronary angiograms from 350 patients randomized to the early invasive strategy in the Veterans Affairs Non–Q-Wave Infarction Strategies in-Hospital (VANQWISH) trial were systematically analyzed in an angiographic core laboratory. A consensus panel identified the culprit lesion and the infarct-related artery using prespecified criteria for complex lesion morphology and acute versus chronic occlusions. Severity of angiographic disease and left ventricular function also were analyzed. Patients with a single identified culprit lesion were compared with those who had multiple apparent culprits and those without an identifiable culprit lesion. Results A single culprit lesion was identified in only 49% of patients undergoing early angiography after NQWMI. The majority of patients either had no identifiable culprit (37%) or multiple apparent culprit lesions (14%). A single incomplete occlusion of the infarct-related artery was found in only 36% of patients, and an isolated acute occlusion of the infarct-related artery occurred in 13%. Patients without an identifiable culprit lesion had severe coronary disease (obstructive coronary artery disease [CAD] in 84%) but no complex lesion morphology. There was no difference in angiographic severity of disease comparing patients with and without identifiable culprit lesions. Patients with a single incomplete occlusion of the infarct-related artery were more likely to undergo percutaneous transluminal coronary angioplasty than other patients, whereas patients with multiple culprit lesions were more frequently treated with coronary artery bypass grafting. Conclusions Coronary angiography early after NQWMI frequently identifies severe obstructive CAD, but a single identifiable culprit lesion was identified in <50% of patients. Multiple culprit lesions were seen in 14% of patients. An angiographic culprit lesion could not be identified in more than one-third of patients undergoing coronary angiography as part of an invasive strategy.