Assessing the Significance of Electrographically Positive Exercise Stress Tests in Patients Attending Cardiac Rehabilitation

PURPOSE: Exercise stress tests (EST) are used to evaluate functional capacity before cardiac rehabilitation (CR). The prognostic value of EST to understand health outcomes in the year following an EST after participating in CR is not well understood. METHODS: We reviewed charts of 488 patients (females, n = 64) who underwent an EST within 100 days of starting CR. The outcomes of revascularization, rehospitalization, mortality, and the combination of revascularization or mortality were compared between patients with positive EST (n = 38), negative EST (n = 123), and nondiagnostic EST (n = 327). RESULTS: The positive EST group displayed significantly higher risk for revascularization or mortality within 1 year post-EST (HR = 13.6: 95% CI, 1.6-119.4; P = .018) compared with the negative EST group. Having a prior coronary artery bypass graft surgery independently increased the hazard of rehospitalization at 1 year (HR = 5.1: 95% CI, 1.9-13.5; P = .001) and the composite endpoint at 1 year (HR = 5.7: 95% CI, 1.6-19.7; P = .006) post-EST. The risk for rehospitalization in females (HR = 2.3: 95% CI, 1.0-5.3; P = .050) was greater than for males at 1 year, warranting future investigation into sex-based differences of long-term health outcomes post cardiac event. CONCLUSIONS: The utility of EST for patients referred to CR has been debated, but our results demonstrate that EST may provide valuable information for prognosis and decision-making in cardiac care pathways.