Transient ischaemia refractory to conventional medical treatment in unstable angina: Angiographic correlates and prognostic implications

Complex stenosis morphology is frequently seen in patients with unstable angina. However, its relation to transient myocardial ischaemia and clinical outcome has not been adequately elucidated. We studied 86 patients admitted to the Coronary Care Unit for unstable angina; all patients underwent ECG Holter monitoring during the first 2-4 days, while receiving intensive triple drug treatment. Coronary angiography and subsequent analysis of the ischaemia-related artery were performed within 12 days of admission. Patients were grouped according to their angiographic features: 45 showed complex coronary morphology (CM: 29 eccentric stenosis with irregular borders or overhanging edges; 16 intracoronary thrombus), 11 had documented coronary spasm as well as moderate atherosclerosis (CS), seven had left main coronary artery disease, and the remaining 23 patients showed regular and smooth morphology of coronary stenosis (RM). At admission, transient myocardial ischaemia (TMI) was greater in patients with CM (85 ± 60 min . 24 h-1) than in those with RM or CS (33 ± 26 min . 24 h-1; P < 0.005). After 3 days of full medical treatment TMI decreased in all groups, but 34/45 patients with CM and 9/34 with RM or CS still showed residual ischaemia (> min . 24 h-1): 76% vs 26%, P < 0.02. Follow-up was obtained at hospital discharge and after 1 year in all patients. The presence of complex coronary features or residual TMI were both predictive of inhospital outcome; indeed, coronary events (death, myocardial infarction or urgent revascularization) were observed in 56% CM vs 9% RM or CS patients, and in 59% vs 14% of those with or without TMI, respectively; both P < 0.001. Following discharge persistence of TMI, but not complex morphology, correlated with clinical outcome. Thus, angiographic evidence of complex coronary lesions was related to sustained TMI at admission, as well as to residual ischaemia after 2-4 days of medical treatment. These features also have prognostic implications, because they are predictive of early coronary events. © 1992 The European Society of Cardiology.