What is the value of stress 99mTc-tetrofosmin myocardial perfusion imaging for the assessment of very long-term outcome in obese patients?

Abstract

ObjectiveThere are no data regarding the long-term prognostic value of single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) in obese patients. The aim of this study was to examine the value of stress 99mTc-tetrofosmin MPI findings for the prediction of very long-term outcome in obese patients. MethodsThe study population consisted of 261 patients with a body mass index ≥30 kg/m2 who underwent exercise or pharmacological stress 99mTc-tetrofosmin MPI for the assessment of known or suspected coronary artery disease. Endpoints during follow-up were all-cause mortality, cardiac death, nonfatal infarction, and coronary revascularization. Kaplan-Meier survival cures were constructed and univariate and multivariate analyses were performed to identify predictors of very long-term outcome. ResultsThe mean age was 59 ± 10 years, 42% of the patients was male, and the body mass index was on average 37 ± 7 kg/m2. MPI findings were normal in 109 patients (42%). Myocardial perfusion abnormalities were fixed in 62 patients (24%) and reversible in 90 patients (34%). During a median 12-year follow-up, 91 (35%) patients died, and 27 (10%) had a nonfatal myocardial infarction. Survival curves were compared using the log-rank test at subsequent follow-up durations. Obese patients with a normal stress 99mTc-tetrofosmin study had a significantly better prognosis as compared with those with an abnormal study, up to 6 years after the test was performed. ConclusionStress 99mTc-tetrofosmin MPI provides valuable prognostic information for the prediction of outcome in obese patients. Obese patients with a normal stress 99mTc-tetrofosmin study have a significantly better prognosis as compared with those with an abnormal study, up to 6 years after the test is performed.