Coronary angiographic morphology in unstable angina: comparative observations of culprit lesions in saphenous vein grafts versus native coronary arteries.

GOAL: To compare angiographic characteristics of culprit lesions in saphenous vein grafts (SVG) with those in native coronary arteries (NCA) in patients presenting with unstable angina (UA).

METHODS: Over 4 years, a total of 445 consecutive patients undergoing coronary angiography and percutaneous coronary intervention during hospitalization for UA were identified using a prospectively collected database. Patients with enzyme or electrocardiographic (ECG) evidence for acute myocardial infarction were excluded. Single culprit lesions in SVGs were identified by angiographic and ECG criteria in 214 patients and in NCAs in 231 patients. Culprit lesions were clearly identifiable by clinical and angiographic correlation in all cases. Morphologic analysis of the culprit lesions was performed using the Ambrose classification.

RESULTS: The SVG group had male predominance (86.4% vs. 66.7%; p = 0001) and was older (67.3 +/- 9.9 years vs. 64.0 +/- 12.2 years; p = 0.0017) compared to the NCA group. Left ventricular ejection fraction was lower in the SVG group (53.8 +/- 15.5% vs. 57.5 +/- 15.2%; p = 0.063). There was a higher incidence of thrombotic-appearing lesions in SVG culprit lesions than in NCAs (31.3% vs. 6.5%; p = 0.001). There was also a higher incidence of ulcerated plaque in SVGs (36.9% vs. 22.1%; p = 0.001). Total occlusions were more common in NCAs (13.0% vs. 7.9%; p = 0.084). The composite incidence of thrombus, ulcerated plaque and total occlusion was more frequent in SVG lesions (59.4% vs. 39.8%; p = 0.001).

CONCLUSIONS: In UA, culprit lesions of SVGs assessed angiographically demonstrate morphology consistent with ulcerated plaque and thrombus more frequently than lesions in NCAs, but total occlusions are more common in NCAs. Angiographically-evident active thrombotic and ulcerated lesions underlie acute ischemic syndromes more frequently in SVGs than in native vessels.