Incremental prognostic value of myocardial perfusion imaging in patients with renal dysfunction

Abstract

Coronary artery disease is the main cause of mortality and morbidity in patients with impaired renal function. The aim of this study is to evaluate the prognostic implications of single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) in patients with impaired renal function. We included 11,829 consecutive patients (mean age, 65 ± 12 years; 52% men) referred for SPECT-MPI between April 2004 and May 2009. Renal function was estimated using the estimated glomerular filtration rate (GFR) formula. Patients were followed up for a composite endpoint of all-cause mortality and nonfatal myocardial infarction (D/MI). Multiple nested Cox proportional hazard models were used to determine the incremental prognostic value of SPECT-MPI over clinical features and renal function. A total of 916 (8%) and 3565 (31%) patients had GFR less 30 and between 30 and 60 mL/min/1.73 m2 respectively. Patients with decreased GFR were more often older, with higher prevalence of conventional risk factors (P < 0.001). After a median follow-up of 5 years (25th to 75th percentiles, 3–6.5 years), 2578 (22%) patients experienced D/MI (764 MI and 2113 dead). The risk of death increased with worsening kidney function. At each stage of impaired renal function, patients with abnormal SPECT-MPI had increased hazard of adverse events (P < 0.0001). Using Cox regression, total perfusion defect offered improved discriminatory ability beyond traditional risk factors (area under the receiver operator curve [AUC] 0.742 vs. 0.759, p < 0.0001). SPECT-MPI adds incremental prognostic information to identify patients at higher relative risk of D/MI across a wide spectrum of renal function.