Nuclear scans: a clinical decision making tool that reduces the need for cardiac catheterization.

We have assessed the impact of cardiovascular nuclear medicine studies (CVNMS) on physicians' decisions to send patients with suspected ischemic heart disease (N = 439) on to cardiac catheterization at three Bronx hospitals. A change in management plans with respect to catheterization was observed in 31% of cases. Catheterization rates were reduced by 25% among patients referred for resting studies and by 49% for exercise studies (thallium perfusion or exercise wall motion studies). Results of CVNMS had little impact on catheterization decisions for resting study patients (N = 192). Among exercise study patients (N = 247), those with normal results had a relative reduction in catheterization post-CVNMS of 82% vs 27% for patients with abnormal results (p less than 0.001). However, impact of exercise CVNMS test results on post-CVNMS catheterization rates obtained for men only; women with abnormal exercise study results were much less likely to undergo subsequent catheterization (7.7%) than men with abnormal results (41.9%), p less than 0.005, independent of age. The apparent discrepancy in referral for catheterization based on sex needs to be investigated further.