warranty period of normal stress myocardial perfusion imaging in hypertensive patients: a parametric survival analysis

We evaluated the warranty period of a normal stress myocardial perfusion single-photon emission computed tomography (mps) in hypertensive patients. a total of 471 consecutive hypertensive patients with suspected coronary artery disease and normal perfusion at stress mps were followed for a mean of 76 ± 21 months. endpoint events were cardiac death or nonfatal myocardial infarction. with cox analysis, age (hazard ratio 1.1, p < .005) and stress test type (hazard ratio 2.7, p < .005) were independent predictors of events. with parametric weibull analysis, patients ≤60 years old undergoing exercise stress test remained at low risk for the entire length of follow-up, while the highest probability of events and the major risk acceleration were observed in those > 60 years old who underwent pharmacologic stress test. in patients undergoing exercise test, peak systolic blood pressure (bp; hazard ratio 1.1, p < .005) emerged as predictor of events, and only subjects with peak systolic bp < 160 mmhg remained at low risk for the entire length of follow-up. in contrast, for patients with peak systolic bp ≥180 mmhg, the time to achieve a cumulative cardiac risk level of 3% was 18 months. in hypertensive patients, the warranty period of a normal stress mps varies according to stress type and peak systolic bp. a normal stress mps can be considered reassuring in subjects ≤60 years old who performed exercise stress test and a peak systolic bp < 160 mmhg.