Gauging the Positive Predictive Value of Exercise Tolerance Test Using Angiographic Evaluation: A Cross-Sectional Analysis From a Developing Country

Background Exercise tolerance test (ETT) and angiographic evaluation are important tools to evaluate patients presenting with ischemic cardiac pathologies. Angiographic evaluation is regarded as the gold standard diagnostic modality to diagnose coronary artery disease (CAD). Our study aims to evaluate the positive predictive value (PPV) of ETT to diagnose CAD using coronary angiography. Methods We conducted a cross-sectional study that analyzed 94 patients with a positive ETT test after the application of strict inclusion and exclusion criteria. All 94 patients were referred for angiography after a positive ETT test. Data collection was performed using a structured proforma, and analysis was carried out on Statistical Package for Social Sciences (SPSS) version 23 (IBM Corp., Armonk, NY). PPV for various demographic characteristics was calculated. Results Out of 94 patients, 76 were males and 18 were females with a mean age of 52.28 ± 7.55 years. A total of 35.1% of the patients had type-2 diabetes, and 31.9% were hypertensive. On coronary angiography, only 25 patients had normal findings, and 69 patients had a significant occlusion in at least one of the major coronary arteries. The overall PPV of the ETT against angiographic evaluation was 73.40%. The PPV for females, hypertensives, non-smokers, and non-diabetics was lower than the PPV of males, smokers, non-hypertensives, and diabetics. Conclusion Angiographic evaluation of patients with positive ETT findings has a high likelihood of false positivity especially among females, non-smokers, hypertensives, and non-diabetics. The results of ETT must be interpreted with caution in these subsets of the population. Invasive radiological modalities can be used for diagnosis; however, such modalities do not elucidate the functioning of myocardium under stress.