Single photon emission computed tomography (SPECT) has been extensively used to evaluate left ventricular (LV) systolic function. However, there are few studies comparing diastolic parameters based on SPECT with established reference values for the assessment of LV diastolic function.

To evaluate the sensitivity of SPECT-estimated LV diastolic parameters in coronary heart disease with left ventricular end-diastolic pressure (LVEDP) examined by left cardiac catheterization as the gold standard for comparison.

Totally 97 patients with suspected or comfired coronary artery disease were prospectively selected from Department of Cardiology, the Affiliated Hospital of Xuzhou Medical University from September 2021 to January 2022. All of them performed echocardiography, coronary angiography with left cardiac catheterization〔estimating LVEDP, left ventricular end-systolic volume (LVESV) , left ventricular end-diastolic volume (LVEDV) and left ventricular ejection fraction (LVEF) 〕, SPECT〔estimating LVESV', LVEDV', LVEF', peak filling rate (PFR) , the first third filling fraction (1/3FF) , the first third filling rate (1/3FR) , mean filling rate (MFR) , and peak filling time (TPF) 〕within one to three days of admission. Based on coronary angiography data, all patients had at least one sub-epicardial coronary artery stenosed to over 50%. The general data, laboratory indices, and indices of left heart function were compared between patients with normal LV diastolic function (n=50, LVEDP<16 mm Hg) and those with LV diastolic dysfunction (n=47, LVEDP≥16 mm Hg) . The correlation of LVEDP with SPECT parameters was analyzed. The receiver operating characteristic (ROC) curve was applied to evaluate the predictive value of SPECT parameters for elevated LVEDP.

Patients with LV diastolic dysfunction had lower LVEF', PFR, 1/3FF, 1/3FR, MFR, and higher TPF (P<0.05) . The results of correlation analysis showed that there was a positive correlation between LVESV' and LVESV, and LVEDV' and LVEDV, LVEF' and LVEF (r_s=0.726, P<0.001; r_s=0.651, P<0.001; r=0.450, P<0.001) . PFR, 1/3FF, 1/3FR or MFR was negatively correlated with LVEDP (r_s=-0.481, r_s=-0.212, r=-0.354, r_s=-0.305, P<0.05) . TPF was positively correlated with LVEDP (r=0.442, P<0.001) . In predicting elevated LVEDP, the area under the ROC curve (AUC) of PFR was 0.778 with 60% sensitivity and 84% specificity, the AUC of 1/3FF was 0.662 with 75% sensitivity and 62% specificity, the AUC of 1/3FR was 0.653 with 57% sensitivity and 78% specificity, the AUC of MFR was 0.663 with 62% sensitivity and 68% specificity, and the AUC of TPF was 0.755 with 77% sensitivity and 70% specificity.

For patients with coronary heart disease and LVEF≥50%, diastolic function parameters obtained by SPECT can identify the increase of LVEDP, among which PFR and TPF indices have good feasibility and higher accuracy.