Diagnostic performance of gated SPECT myocardial perfusion imaging for early detection of diastolic dysfunction in diabetic patients: A comparative study with echocardiography

Diabetic patients are at high risk for developing diabetic cardiomyopathy, often initially presenting as left ventricular diastolic dysfunction (LVDD). While echocardiography is the standard for diagnosing LVDD, Gated SPECT (GSPECT) offers simultaneous assessment of perfusion and function. This study aimed to evaluate the diagnostic value of diastolic parameters derived from GSPECT for detecting LVDD in diabetic patients without known heart disease, using echocardiography as a reference.

In this cross-sectional study, 60 diabetic patients without a history of cardiac disease underwent both GSPECT myocardial perfusion imaging and echocardiography within a two-week period. Diastolic function was assessed on GSPECT using peak filling rate (PFR) and time to peak filling rate (TTPFR). Echocardiography served as the gold standard for classifying diastolic function as normal, grade 1, or grade 2 dysfunction. Diagnostic accuracy, sensitivity, and specificity of GSPECT parameters were calculated.

Based on echocardiography, 51.7% of patients had LVDD (45% grade 1, 6.7% grade 2). The PFR derived from GSPECT demonstrated a sensitivity of 87% and a specificity of 48.2% for detecting LVDD, with an overall accuracy of 68.3%. TTPFR showed high sensitivity (90.3%) but low specificity (17.2%). A significant correlation was found between the ischemia pattern on GSPECT and the presence of diastolic dysfunction (p=0.01). Lower PFR values were significantly associated with male gender, age >60 years, and smoking.

Gated SPECT, particularly the PFR parameter, shows high sensitivity for the detection of LVDD in asymptomatic diabetic patients. Incorporating diastolic function analysis into routine GSPECT reporting can provide valuable incremental information for the early diagnosis and risk stratification of diabetic cardiomyopathy.