The estimated glomerular filtration rate (eGFR), which represents renal function, might play an important role in identifying high-risk diabetic persons who would benefit most from myocardial perfusion imaging (MPI) by SPECT for suspected ischemia, according to a study published in this month's Journal of the American College of Cardiology: Cardiovascular Imaging.
Chronic kidney disease (CKD) defined by an eGFR less than 60 ml/min and myocardial perfusion defects are powerful prognostic indicators to help identify diabetic persons at high risk for both cardiac and all-cause mortality, explained Abdul Hakeem, MD, from the division of cardiovascular diseases at the University of Cincinnati College of Medicine.
Hakeem and colleagues followed 1,747 patients (average age 65, 37 percent diabetic) undergoing MPI for cardiac death for two years in the study.
The researchers found that in the presence of a normal scan, annual cardiac death rate was 0.9 percent for those with no diabetes and no CKD, 0.5 percent in the diabetes alone group, 2.35 percent in CKD alone and 2.9 percent in those with both diabetes and CKD.
Thus, patients with diabetes plus CKD had a 2.7-fold risk of cardiac death compared with no diabetes and no CKD after controlling for age, ejection fraction, history of coronary artery disease and other risk factors, according to Hakeem and colleagues.
The researchers also observed that the risk of cardiac death increased as a function of the presence and severity of perfusion defects, regardless of CKD or diabetes status. Presence of a normal scan in diabetic persons with CKD or those with CKD alone was associated with a less benign prognosis.
MPI and eGFR provide valuable risk stratification for diabetic and nondiabetic patients. "Diabetic patients without CKD have a relatively good short-term outcome almost comparable to nondiabetic patients. Hence, the increased cardiovascular morbidity in diabetic persons might largely be due to underlying renal dysfunction,” concluded Hakeem and colleagues.