Determination of vessel size: a putative framework to assess clinical outcome

Background Unknown is the predictive value of the coronary artery diameter without the administration of vasomotor stimuli. A small reference diameter of the target vessel has been demonstrated to be an adverse prognostic factor in patients undergoing revascularisation. The present study investigated the prognostic value of the proximal non-stenotic left anterior descending coronary artery (LAD) diameter in patients referred for a first diagnostic angiogram without a previous revascularisation. Methods A total of 277 patients (mean age 57 year, 61% male) were eligible for analysis. The proximal non-stenotic diameter of the LAD was measured by quantitative coronary angiography without prior nitrate infusion. We defined a small LAD as a diameter ≤2.5 mm. Cardiovascular events were defined as cardiac death, myocardial infarction, and hospitalizations for unstable angina. Results During a median follow-up of 47 months, 24 major cardiac events occurred. The cumulative survival for patients with a small LAD was significantly lower, than for patients with a large LAD (hazard ratio 2.51; 95% confidence interval 1.11–5.66, p=0.03). In the multivariate analysis, a LAD diameter ≤2.5 mm remained a significant predictor of cardiovascular events after adjustment for age, gender, and the presence of significant coronary artery disease (hazard ratio 2.32; 95% confidence interval 1.01–5.34, p=0.048). Conclusion In patients referred for a first diagnostic angiogram without a previous revascularisation, the diameter of the proximal non-stenotic LAD is an independent predictor of cardiovascular events.