Study of the Correlation Between the Ratio of Diastolic to Systolic Durations and Echocardiography Measurements and Its Application to the Classification of Heart Failure Phenotypes

BACKGROUND: This study aimed to investigate the correlation between the ratio of diastolic to systolic durations (D/S) and echocardiographic parameters of patients with chronic heart failure (CHF) and evaluate whether the D/S can be used as a supplementary biomarker for the classification of heart failure (HF) phenotypes. METHODS: In total, 122 CHF patients with a left ventricular ejection fraction (LVEF) <40%, 40%≤LVEF<50%, or ≥50% were categorized as having HF with a reduced ejection fraction (HFrEF) (N=32), HF with a mid-range ejection fraction (HFmrEF) (N=21) or HF with a preserved ejection fraction (HFpEF) (N=69), respectively. All patients underwent echocardiography for assessment of nineteen structural and functional echocardiographic parameters and digital phonocardiography for the measurement of D/S. Spearman correlation was used to analyse the associations between the D/S and echocardiographic parameters. Multivariate logistic regression analysis was performed to examine the associations between the D/S and HF phenotypes, and receiver operating characteristic (ROC) curve analysis was employed to evaluate the predictive value of the D/S in the classification of HF phenotypes. RESULTS: The D/S values of patients with HFrEF, HFmrEF and HFpEF were 1.32±0.06, 1.44±0.11 and 1.54±0.08, respectively, which were significantly different (All P<0.05). A close correlation between the D/S and LVEF was found (r=0.777, P<0.001). The multivariate analysis indicated that the D/S was an independent risk factor for CHF phenotypes (OR=4.927, 95% CI 2.532–9.587; P<0.001). The area under the ROC curve for distinguishing between HFmrEF and HFpEF using the D/S was 0.764 (95% CI 0.707–0.845; P < 0.001) and that for distinguishing between HFmrEF and HFrEF using the D/S was 0.821 (95% CI 0.755–0.882; P < 0.001). CONCLUSION: The D/S was significantly associated with LVEF, and as LVEF decreased, the D/S tended to decrease, which could also serve as a noninvasive supplementary indicator for detecting systolic and diastolic dysfunction.