Prognostic value of dipyridamole thallium-201 imaging in elderly patients

Abstract

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)

Prognostic Implications of Myocardial Perfusion Single-Photon Emission Computed Tomography in the Elderly

“…Hence, cardiac event rates after normal single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy (MPS) may no longer be uniformly "low" (Ͻ1%/y). 4,8 To understand the implications of MPS in the elderly, it is important to define the ability of the test to stratify risk and to yield incremental value in multiple patient subsets. To date, prognostic studies in elderly populations are limited in size and power, particularly relative to pharmacological stress [5][6][7][8][9][10][11] and the value of gated MPS.…”

Value of nuclear cardiology for the diagnosis and risk stratification of coronary artery disease

“…(52) Other publications state that event rates following a normal MPI can be infl uenced by age and comorbidity taking the hard event rates to between 1.3% and 2.7% in elderly patients stressed pharmacologically. (52)(53)(54)(55) Still, as a group, patients with a normal MPI study are at very low risk of hard event during the fi rst year post-test. (56) When an MPI is found to be abnormal, the risk for hard events is related to the severity of the abnormality; the greater the affected area, the higher the risk.…”

Preoperative strategies to assess cardiac risk before noncardiac surgery

“…2). [23][24][25][26][27][28][29][30][31][32][33][34] Thc pooled data for dipyridamole myocardial perfusion imaging reveal a positive and negative predictive value of 36 f: 1 1 % and 07 i 2%, respectively. The positive predictive value of a severe defect, defined as a multisegmental, reversible defect or a combination of fixed and reversible defect for cardiac events was 45 * 5% and is associated with an increased incidence of postoperative death and myocardial infarction.…”