Implications of small reference vessel diameter in patients undergoing percutaneous coronary revascularization

OBJECTIVES The purpose of this study was to determine whether small reference diameter of the culprit coronary artery influences the outcome of an attempted percutaneous revascularization procedure in the current era of interventional cardiology. BACKGROUND Alhough the interventional strategy is largely determined by the size of the culprit coronary artery, earlier quantitative studies have not shown a worse acute outcome for small reference vessel diameter (less than or equal to 2.5 mm). METHODS A total of 2,306 patients undergoing percutaneous coronary revascularization was divided in groups with reference diameters less than or equal to 2.5 mm (n = 813) or >2.5 mm (n = 1,493). Success and in-hospital major adverse cardiac event (death, Q-wave myocardial infarction and emergency coronary artery bypass graft) rates between both groups were compared. RESULTS Patients with lesions in small vessels were older and presented more frequently with female gender, diabetes mellitus, heart failure, peripheral vascular, multivessel coronary disease and American Heart Association/American College of Cardiology (AHA/ACC) lesion type C (p less than or equal to 0.01, each). Further, utilization of interventional devices differed markedly. In contrast to stents (18.5% vs. 41.9%) and directional atherectomy (3.7% vs. 13.5%), conventional balloon angioplasty (73% vs. 50%) and rotational atherectomy (16.1% vs. 8.3%) were used more often in smaller vessels (p less than or equal to 0.0001, each). Success rate was lower in the small vessel group (92% vs. 95%; p = 0.006). Major adverse cardiac events occurred more frequently in small than large vessels (univariate 3.4% vs. 2.0%, p = 0.03; multivariate odds ratio 2.1, p = 0.02), particularly when proximal coronary segments were compared. CONCLUSIONS Lesions in vessels with small reference diameter represent a distinct group with respect re, clinical and morphologic characteristics as well, as device utilization. These lesions have lower chances of successful percutaneous intervention and carry relatively higher risks, specifically when located in proximal coronary segments. (C) 1999 by the American College of Cardiology.