Prediction of cardiovascular events in pre-dialysis chronic kidney disease patients with normal SPECT myocardial perfusion imaging

Abstract

Purpose: Patients with normal stress myocardial perfusion imaging (MPI) results generally have an excellent prognosis with <1% cardiovascular events/year. Chronic kidney disease (CKD) is an established risk factor for cardiovascular events. However, the estimated glomerular filtration rate (eGFR) varies considerably among patients with CKD. We evaluated the prognostic value of eGFR for patients with CKD who did not undergo hemodialysis and had no evidence of coronary artery disease (CAD).

Methods and subjects: Patients with CKD (n=108; 58 males; mean age: 74 years) with no CAD [no previous CAD and normal stress MPI results; summed stress score (SSS) <4] and with no history of hemodialysis were followed-up (mean duration: 24 months). CKD was defined by eGFR of <60 ml/min/1.73 m(2) and/or persistent proteinuria. Cardiovascular events included cardiac death, non-fatal myocardial infarction, and unstable angina.

Results: Cardiovascular events were observed in 8 patients with CKD (7%). The following were determined as significant predictors of these events: age (hazard ratio=1.14; p=0.019), hemoglobin levels (hazard ratio=0.69; p=0.021), eGFR (hazard ratio=0.94; p=0.008), SSS (hazard ratio=2.31; p=0.012), and summed difference score (hazard ratio=2.33; p=0.014).

Conclusions: Patients with CKD and with no previous CAD and normal stress MPI results (SSS<4) may not exhibit an excellent cardiovascular prognosis. Further, a lower eGFR and stress MPI results may be the predictors of cardiovascular events. Thus, patients with a lower eGFR and/or normal stress MPI results (SSS<4) may require continuous follow-up.

Keywords: Myocardium; Prognosis; Radionuclide imaging; Renal function.