Positive Predictive Value of Noninvasive Stress Testing Is Poor in the Real World

Abstract

Abnormal noninvasive stress test (NIST) findings do not always correlate with angiographically significant (luminal obstruction ≥50%) coronary artery disease. Positive predictive value (PPV) of NIST in the real clinical practice is not well known. The goal of this retrospective study was to determine the PPV of NIST and assess the factors affecting PPV in a US community hospital. This study included all consecutive patients (n = 355) who underwent invasive coronary angiography after a positive NIST within ~1-year duration at our institution. Three hundred twenty-four patients were included in the analysis after exclusion of 31 patients. Sixty percent of patients were female and mean age was 63.2 (SD 12.4). Myocardial perfusion imaging, echocardiogram (treadmill or dobutamine), and treadmill electrocardiogram were the tests of choice in 95% (n = 307), 4% (n = 14), and 1% (n = 3) of patients, respectively. Overall PPV of NIST was 36.4% (118/324). When patients were stratified by age (<50 years, 50-65 years, ≥65 years), older age groups had significantly higher PPV (<0.001). When patients were grouped by body mass index (<25, 25-30, ≥30), those in lower body mass index groups had higher PPV (P = 0.01). Stress echocardiogram had significantly higher PPV compared with myocardial perfusion imaging stress test (71% vs. 35%; P < 0.005). Stress test site (in-hospital vs. outpatient office) or specialty of interpreting physician did not significantly impact PPV. Multivariable logistic regression analysis revealed that older age, male sex, and total number of cardiac risk factors were significant determinants of higher PPV. Our single-center study revealed that overall PPV of NIST is poor (36.4%), more notably in young, female, or obese patients.