Comparative value of the cold-pressor test and supine bicycle exercise to detect subjects with coronary artery disease using radionuclide ventriculography.

Abstract

Left ventricular ejection fraction (EF) and wall motion studies were performed using blood pool cardiac scintigraphy before and during the cold-pressor test (CPT) and bicycle exercise. Twenty normal subjects responded to the CPT with no change or a significant increase (.gtoreq. 7%) of the EF and no new wall motion abnormalities. Mean EF increased significantly (P < 0.01). Two subjects responded abnormally to the CPT, one with a significant decrease (.gtoreq. 7%) in EF and another with the development of new wall motion abnormalities. During exercise, EF increased significantly in all but 1 subject (P < 0.001). No new wall motion abnormality was seen. In 20 patients with coronary artery disease (CAD) and normal resting left ventricular function, mean EF decreased (P < 0.001) during the CPT, but only 11 patients could be identified individually by a drop in EF of .gtoreq. 7%. During exercise, 18 of the 20 patients responded abnormally (failure to increase EF by .gtoreq. 7%). Twelve patients showed new wall motion abnormalities during CPT and 15 during exercise. Three patients during the CPT and one during exercise had normal EF response while developing new wall motion abnormalities. The sensitivity of radionuclide EF changes during the CPT to detect subjects with CAD was 55%. It increased to 70% when wall motion analysis and EF changes were considered. The specificity was then 90% and the predictive accuracy was 88%. The sensitivity of radionuclide studies during exercise, considering EF changes and wall motion analysis under otherwise similar conditions, was 95%. Specificity and predictive accuracy were also 95%. The CPT is not as sensitive as exercise for detecting subjects with CAD by radionuclide cardiac angiography. The CPT may be a useful intervention in subjects in whom adequate exercise cannot be accomplished.