INFLUENCE OF CORONARY VESSEL SIZE ON RENARROWING PROCESS AND LATE ANGIOGRAPHIC OUTCOME AFTER SUCCESSFUL BALLOON ANGIOPLASTY

Background Although coronary angioplasty is increasingly applied in th e treatment of multivessel disease and a broadening range of vessel si ze, the influence of vessel size itself on the late results of interve ntion is unresolved. An influence of vessel size on late outcome would carry implications for the application and evaluation of intervention al devices, which are selectively used in larger or smaller vessels. T he purpose of the present study was to investigate the influence of ve ssel size on both the restenosis process and late angiographic outcome in a large homogeneous patient group after successful percutaneous tr ansluminal coronary angioplasty (PTCA). Methods and Results The study population comprised 3072 patients with 3736 successfully dilated nati ve primary coronary artery lesions and satisfactory quantitative angio graphic analysis in multiple identical projections before and after PT CA and at a 6-month follow-up. Late luminal loss, minimal luminal diam eter (MLD) at follow-up, and net luminal gain, as well as percent diam eter stenosis at follow-up, net gain in percent diameter stenosis, res tenosis rates (according to three definitions), and net gain index, we re all compared among nine equally sized groups (noniles) according to vessel size. A direct influence of vessel size on continuous measures of late result was also evaluated by linear regression. These evaluat ions provided conflicting information with no consistent influence of vessel size emerging. To elucidate the independent influence of vessel size on the restenosis process (late loss) and late angiographic outc ome (MLD at follow-up), multiple linear regression analysis was perfor med taking into account luminal gain, preprocedural MLD, and lesion lo cation. In this manner, vessel size was found to be exert a significan tly positive influence on MLD at follow-up (P<.0001) and an equally ne gative effect on loss. Correcting for vessel size by using percent ste nosis measurements led to an anticipated neutralization of this influe nce. Lesion location in the left anterior descending coronary artery w as found to be independently associated with greater loss and smaller MLD at follow-up (P<.0001). Conclusions Increasing coronary vessel siz e was found to be independently predictive of decreasing late luminal loss and increasing follow-up MLD after successful balloon angioplasty . Apparently superior or inferior late angiographic results of new int erventional devices may thus be explained in part by preferential use in larger or smaller vessels, respectively. Devices that can safely op timize the short-term result of intervention may realize their ultimat e long-term value in larger coronary vessels.