Percutaneous transluminal coronary angioplasty was performed at the time of the diagnostic catheterization in 188 patients (215 lesions) at a University Hospital in order to assess the efficacy of this approach and the potential role it should play in the evaluation and treatment of patients. Patients either presented for diagnostic catheterization for evaluation of stable coronary disease (79 patients) or for unstable or new onset anginal symptoms (109 patients). Lesions were graded as to whether they were simple or complex; and post angioplasty films were reviewed for success rate, and degree of revascularization. Patients who were referred for stable anginal symptoms had a slightly higher success rate (91%) compared to those who were referred for new onset or more unstable symptomatology (85%, p = ns). Additionally, lesions morphology was judged to be more complex in unstable patients, as 67% had complex lesions with the presence of thrombus or ulcerated plaque in 56% of these stenoses. Angioplasty success was high for simple lesions in all patients, but was most unfavorable for complex stenoses in patients who presented with unstable symptoms (81% success rate). In patients who presented with new onset or unstable symptoms multivessel disease was present in 69% and angioplasty was more often geared at dilating a culprit stenosis leaving only 49% of these patients with complete revascularization. On the other hand, in 76% of those patients who presented with stable angina complete revascularization was a common outcome. Length of hospital stay was considerably shorter at 2.9 +/- 0.8 days in those patients who presented with stable symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)