Short‐ and long‐term prognostic performance of exercise ECG and myocardial perfusion SPECT

Abstract

AbstractBackgroundMyocardial perfusion SPECT (MPS) and exercise electrocardiography (Ex‐ECG) results are of prognostic importance for short‐term follow up duration. However, the value of MPS or Ex‐ECG findings for long‐term risk assessment is less evident as underlying risk factors for ischemic heart disease (IHD) gain in importance.ObjectivesTo assess the short‐ and long‐term prognostic value of MPS and Ex‐ECG in relation to known risk factors.Methods and MaterialsAn observational study of 908 patients (age 63 years, 49% male, 45% prior IHD) referred for MPS and Ex‐ECG. Follow‐up was divided into two periods (short‐term: <5 years and long‐term: >5 years). Cardiac events were defined as a composite of acute myocardial infarction, unstable angina, unplanned revascularization and cardiovascular death.ResultsThe composite endpoint occurred in 95 patients (short‐term follow up) and in 94 patients (long‐term follow up). In multivariable models stress testing had a strong predictive value for short‐term follow up (HR for MPS = 2.9, CI = 1.9–4.5, p < 0.001 and HR for Ex‐ECG = 2.1, CI 1.3–3.3, p = 0.002), but no predictive value for long‐term follow up (HR for MPS = 0.9, CI = 0.5–1.5, p = 0.70 and HR for Ex‐ECG = 1.0, CI = 0.6–1.6, p = 0.92). Male sex and prior IHD were significant predictors regardless of follow up duration. Age, diabetes and decreased exercise capacity were risk factors for long‐term follow up.ConclusionsThe prognostic value of MPS and Ex‐ECG results are strong for short‐term follow up but diminish over time and do not contribute significantly in multivariable models after 5 years. Long‐term prognosis is primarily governed by underlying risk factors and exercise capacity.