Abstract 3270: Hemodynamic and Prognostic Implications of Net Atrioventricular Compliance in Patients with Mitral Stenosis: Exercise Echocardiographic Study
Background-On the basis of the close association of left atrial(LA) compliance with pulmonary hypertension in patients with mitral stenosis(MS), we hypothesized that 1) Doppler-derived net atrioventricular compliance (Cn) can be used for predicting the occurrence of mitral valve(MV) replacement or percutaneous mitral commissurotomy(PMC), and 2) determinants of exercise capacity are variable depending on Cn.
Methods-We consecutively enrolled 26 patients(22 women; mean age, 47.0 ± 6.1 years and range, 35 ± 59) with pure moderate or severe MS, in whom comprehensive echocardiography was performed at rest. Cn was derived from the equation that has been previously validated(Cn < 1270 x (MV area by 2D planimetry /mitral E-wave downslope)). Measurements of stroke volume and systolic pulmonary artery pressure (sPAP) were repeated immediately after symptom-limited treadmill exercise test within 60 seconds.
Results- On the basis of earlier reports, Cn < 4ml/mmHg was selected to define abnormally small Cn. Over a mean duration of 24-month follow-up, Cn < 4 mL/mmHg could reliably predict the occurrence of either MV replacement or PMC, which was confirmed by multivariate analysis. In patients with Cn < 4mL/mmHg, exercise duration was found to be closely correlated with resting sPAP(r = −0.73, P = 0.03), whereas in patients with Cn < 4mL/mmHg, post-exercise stroke volume was the only determinant of exercise capacity(r = 0.49, P = 0.04).
Conclusions-In moderate or severe MS, LA compliance estimated by Cn with Doppler echocardiography allows us to effectively predict the event of MV replacement or PMC. In addition, determinants of exercise capacity were variable depending on the degree of Cn.