OBJECTIVE: Normal stress myocardial perfusion imaging (MPI) studies generally suggest an excellent prognosis for cardiovascular events. Chronic kidney disease (CKD), diabetes and peripheral artery disease (PAD) have been established as the risk factors for cardiovascular events. However, whether these risk factors significantly predict cardiovascular events in patients with normal stress MPI is unclear. The purpose of this study was to evaluate the prognostic value of these risk factors in patients with normal stress MPI. METHODS: Patients with normal stress MPI (n = 372, male = 215 and female = 157, age = 69 years, CKD without hemodialysis = 95, diabetes = 99, PAD = 19, previous coronary artery disease = 116) were followed up for 14 months. Normal stress MPI was defined as a summed stress score of <4 and a summed difference score of <2. CKD was defined by an estimated glomerular filtration rate of <60 ml/min/1.73 m(2) and/or persistent proteinuria. Cardiovascular events included cardiac death, non-fatal myocardial infarction and congestive heart failure requiring hospitalization. RESULTS: Cardiovascular events occurred in 20 of 372 patients (5.4%). In univariate Cox regression analysis, PAD, diabetes, diabetic retinopathy, insulin use, anemia, hypoalbuminemia, CKD, left ventricular ejection fraction and pharmacological stress tests were significant predictors of cardiovascular events. In multivariate Cox regression analysis, PAD, diabetes and CKD were independent and significant predictors for cardiovascular events, and their number was the strongest predictor for cardiovascular events (hazard ratio = 21.7, P < 0.001). CONCLUSIONS: PAD, diabetes and CKD are coexisting, independent and significant risk factors for cardiovascular events, CKD being the strongest predictor. The number of coexisting risk factors is important in predicting cardiovascular events in patients with normal stress MPI.
OBJECTIVE: Normal stress myocardial perfusion imaging (MPI) studies generally suggest an excellent prognosis for cardiovascular events. Chronic kidney disease (CKD), diabetes and peripheral artery disease (PAD) have been established as the risk factors for cardiovascular events. However, whether these risk factors significantly predict cardiovascular events in patients with normal stress MPI is unclear. The purpose of this study was to evaluate the prognostic value of these risk factors in patients with normal stress MPI. METHODS:Patients with normal stress MPI (n = 372, male = 215 and female = 157, age = 69 years, CKD without hemodialysis = 95, diabetes = 99, PAD = 19, previous coronary artery disease = 116) were followed up for 14 months. Normal stress MPI was defined as a summed stress score of <4 and a summed difference score of <2. CKD was defined by an estimated glomerular filtration rate of <60 ml/min/1.73 m(2) and/or persistent proteinuria. Cardiovascular events included cardiac death, non-fatal myocardial infarction and congestive heart failure requiring hospitalization. RESULTS: Cardiovascular events occurred in 20 of 372 patients (5.4%). In univariate Cox regression analysis, PAD, diabetes, diabetic retinopathy, insulin use, anemia, hypoalbuminemia, CKD, left ventricular ejection fraction and pharmacological stress tests were significant predictors of cardiovascular events. In multivariate Cox regression analysis, PAD, diabetes and CKD were independent and significant predictors for cardiovascular events, and their number was the strongest predictor for cardiovascular events (hazard ratio = 21.7, P < 0.001). CONCLUSIONS: PAD, diabetes and CKD are coexisting, independent and significant risk factors for cardiovascular events, CKD being the strongest predictor. The number of coexisting risk factors is important in predicting cardiovascular events in patients with normal stress MPI.