Objective: To evaluate the usefulness of ratio of early diastolic transmitral flow velocity (E) to mitral annular velocity (e') calculated by simultaneously recording E and e' in coronary heart disease (CHD) patients.
Methods: A total of 77 CHD patients with preserved systolic functions underwent echocardiography. Left ventricular catheterization was performed to measure left ventricular end diastolic pressure (LVEDP). The accuracy of E/e' was compared by recording the dual-Doppler and conventional methods for diagnosing diastolic dysfunction and the relationships between N-terminal pro-brain natriuretic peptide (NT-proBNP). The validity of E/e'dual Doppler and combined E/e'dual Doppler and NT-proBNP in estimating left ventricular diastolic dysfunction namely LVEDP ≥ 12 mmHg (1 mmHg = 0.133 kPa) were estimated.
Results: E/e'dual Doppler was correlated with left ventricular end diastolic pressure (LVEDP) and logNT-proBNP (r = 0.79, r = 0.47, respectively, P < 0.01). E/e'conventional was correlated with LVEDP and logNT-proBNP (r = 0.61, P < 0.01, r = 0.35, P < 0.05, respectively). The area under curve (AUC) of E/e'dual Doppler and E/e'conventional was 0.87 and 0.82. The optimal cut-off of E/e'dual Doppler was 9.2 with a sensitivity of 74% and a specificity of 81%. And the optimal cut-off of plasma NT-proBNP was 108 ng/L with a sensitivity of 69% and a specificity of 86%, AUC 0.79.When E/e'dual Doppler ≥ 9.2 and NT-proBNP ≥ 108 ng/L were combined, the sensitivity and specificity for diagnosing diastolic dysfunction were 86% and 69%, AUC 0.89.
Conclusion: The accuracy of E/e'dual Doppler is better than E/e'conventional for diagnosing left diastolic dysfunction. When E/e'dual Doppler and NT-proBNP are combined, it improves the evaluation accuracy of left diastolic dysfunction.