The results of an observational multicenter angioplasty study suggested that stenting decisions may be facilitated by physiologic data. The purpose of this study was to evaluate the early and long-term clinical and angiographic outcome of prospective physiologically guided provisional stenting. Coronary angioplasty using a Doppler-tipped angioplasty guidewire was performed in 68 patients. The provisional stent strategy dictated that balloon angioplasty was to be continued until a coronary flow reserve was >/= 2.2 with a residual diameter stenosis by quantitative coronary angiography < 35%. Repeat coronary angiography was obtained at 6 months. Based on the study criteria, 32/68 patients (47%) received a stent. Compared to the stent group, the angioplasty alone group had higher postprocedural stenosis (23% +/- 13% vs. 13% +/- 10%; P < 0. 05) and lower coronary vasodilatory reserve (2.3 +/- 0.4 vs. 2.6 +/- 0.7; P < 0.05). At follow-up (6.0 +/- 1.5 months), the angiographic restenosis rate was 39% in the angioplasty group and 35% in the stent groups (P = NS). Adverse cardiac events (unstable angina, target lesion revascularization, myocardial infarction, death) occurred in 19% and 18% (P = NS) of the angioplasty and stent patients, respectively. A prospective application of a physiologically guided provisional stent strategy for coronary angioplasty indicated that stent implantation may be required in approximately 50% of patients, an approach that produces similar clinical and angiographic long-term outcomes for stenting and guided angioplasty. These data support a role of coronary physiology as an adjunct in conducting an angioplasty procedure without obligatory stenting.