Three-dimensional analysis of vulnerable segments in the left anterior descending artery

Analysis of conventional angiograms has suggested that specific anatomic parameters of particular segments of a coronary artery render them prone to vulnerable plaque development, plaque rupture, and consequent thrombosis. This study aimed at performing a three-dimensional analysis of recanalized left anterior descending (LAD) coronary arteries in patients who had suffered an anterior ST-elevation myocardial infarction (STEMI).

Coronary angiograms of 76 consecutive patients with an anterior STEMI and a recanalized LAD were reconstructed in the three-dimensional space, and compared with angiograms of 76 patients with stable coronary artery disease (SCAD) and significant LAD stenosis.

In both groups the majority of lesions occurred between 20 and 40 mm (P=0.745), but the number of lesions beyond 60 mm from the ostium was significantly higher in SCAD compared with STEMI (P=0.045). Culprit lesions were statistically significantly longer in patients with STEMI compared with SCAD (18.3+/-7.5 vs. 12.7+/-6.2 mm, P<0.001). Cut-off point analysis indicated a lesion length of >or=12.5 mm as discriminating threshold between SCAD and STEMI (sensitivity 79% and specificity 63%). Bifurcation branches on the culprit lesion were seen in 79% of the patients with STEMI and 58% of those with SCAD (P=0.026). Lesion angulation was significantly sharper in STEMI compared with SCAD patients in diastole (155+/-15 vs. 160+/-14 degrees, P=0.037). Multiple logistic regression model including these parameters had a high discriminating ability with c-statistic 0.78 (95% confidence intervals: 0.71-0.86), sensitivity 72.4%, and specificity 75%.

Specific anatomic characteristics of LAD segments predispose to development of plaque rupture and thrombosis.