IMPACT OF MYOCARDIAL PERFUSION SINGLE-PHOTON EMISSION COMPUTED-TOMOGRAPHY ON REFERRAL TO CATHETERIZATION OF THE VERY ELDERLY - IS THERE EVIDENCE OF GENDER-RELATED REFERRAL BIAS

Objectives. This study sought to assess the impact of myocardial perfu sion studies on subsequent: management in the very elderly with respec t to referral to catheterization or revascularization. Background. The very elderly are a rapidly growing segment of the U.S. population, an d myocardial perfusion studies are frequently performed in this patien t subset for evaluation of coronary artery disease. Methods. The study utilized 1,006 consecutive patients greater than or equal to 80 gears old (511 men, 495 women) who underwent stress myocardial perfusion si ngle-photon emission computed tomography (SPECT) using pharmacologic s tress (n = 605) or treadmill exercise (n = 401). Referral to catheteri zation or revascularization within 60 days of the nuclear scan was cor related with clinical and nuclear variables. Results. Catheterization and revascularization mere performed in 119 and 77 patients, respectiv ely. Stratification of referral rates showed a low rate in normal and mildly abnormal scan categories and significantly higher rates in pati ents with severely abnormal scan results irrespective of the presentin g symptoms or pretest likelihood of coronary artery disease, Multiple logistic regression analysis of clinical and nuclear variables reveale d that extent and severity of reversibility by SPECT and the final sca n result were the two most powerful predictors of referral to catheter ization and revascularization in men and women (catheterization: chi-s quare 65 and 78; revascularization: chi-square 37 and 68, respectively ). Overall, referral rates to catheterization and revascularization we re similar in men and women (catheterization: 13% vs. 11%; revasculari zation: 8% vs. 8%, respectively). However, women with severely abnorma l scan results were more frequently referred to catheterization (28% v s. 18%, p < 0.03) and revascularization (21% vs. 12%, p < 0.01) than m en. Conclusions. In patients greater than or equal to 80 years old, my ocardial perfusion SPECT had a significant impact on patient managemen t. The apparent discrepancy in referral rates for interventional manag ement in men and women is unexplained hut mag be appropriate in light of our previous observations that women with severely abnormal scan re sults are at increased risk for hard cardiac events than are men with severely abnormal scan results.