- Background: Although the outcome of patients with angiographically insignificantly narrowed coronary arteries (INCA) is not clearly defined, such lesions can progress or rupture, thus causing cardiovascular morbidity. Preventive therapy with aspirin and lipid-lowering drugs therefore seems warranted in these patients. Hypothesis: The study was undertaken to evaluate the attitude and practice of physicians toward the provision of preventive treatment to patients with INCA. Methods: The attitude of physicians was evaluated using written case histories of three patients with identical clinical features but different angiographic diagnoses. We then examined randomly chosen files of 130 patients with angiographically normal coronary arteries, 130 patients with INCA, and 130 patients with significant coronary artery disease, in relation to the use of lipid-lowering medications and achieved lipoprotein levels. Results: For the hypothetical patients, more physicians prescribed statins (78 vs. 47%, p < 0.0001) and aspirin (89 vs. 74%, p < 0.003) for patients with significant disease than they did for those with INCA. A target low-density lipoprotein (LDL) cholesterol of < 100 mg/dl was considered appropriate for significant disease by 85% of physicians compared with 40% for INCA (p < 0.0001). In the real patients, more of those with significant disease received lipid-lowering drugs and achieved the LDL target level than did those with INCA. Conclusions: Many physicians regard the need to prescribe preventive treatment as less important for patients with INCA than for patients with significant coronary disease. Additional long-term studies are warranted to elucidate the prognostic significance of INCA and the efficacy of preventive therapy in these patients.