The prognostic value of intravenous
dipyridamole myocardial perfusion imaging has not been studied in a large series of elderly patients. Patients greater than or equal to 70 years of age with known or suspected
coronary artery disease were evaluated to determine the predictive value of intravenous
dipyridamole thallium-201 imaging for subsequent
cardiac death or nonfatal
myocardial infarction. Of the 348 patients, 207 were symptomatic and 141 were asymptomatic; 52% of the asymptomatic group had documented
coronary artery disease. During 23 +/- 15 months of follow-up, there were 52 cardiac deaths, 24 nonfatal
myocardial infarctions and 42 revascularization procedures (percutaneous transluminal coronary angioplasty in 20;
coronary artery bypass surgery in 22). Clinical univariate predictors of a
cardiac event included previous
myocardial infarction,
congestive heart failure symptoms,
hypercholesterolemia and diabetes (all p less than 0.05). The presence of a fixed, reversible or combined
thallium-201 defect was significantly associated with the occurrence of
cardiac death or
myocardial infarction during follow-up (p less than 0.05).
Cardiac death or nonfatal
myocardial infarction occurred in only 7 (5%) of 150 patients with a normal
dipyridamole thallium-201 study (p less than 0.001). Stepwise logistic regression analysis of clinical and
radionuclide variables revealed that an abnormal (reversible or fixed)
dipyridamole thallium-201 study was the single best predictor of
cardiac events (relative risk 7.2, p less than 0.001). As has been demonstrated in younger patients, previous
myocardial infarction (relative risk 1.8, p less than 0.001) and symptoms of
congestive heart failure at presentation (relative risk 1.6, p = 0.02) were also significant independent clinical predictors of
cardiac death or
myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)