Echocardiographic parameters in patients with pulmonary arterial hypertension: correlations with right ventricular ejection fraction derived from cardiac magnetic resonance and hemodynamics.

BACKGROUND

Echocardiography is the most convenient method used to evaluate right ventricular function, and several echocardiographic parameters were studied in previous studies. But the value of these parameters to assess the right ventricular function in patients with pulmonary arterial hypertension (PAH) has not been well defined.

METHODS

Patients with PAH were observed prospectively. Right heart catheterization, echocardiography and cardiac magnetic resonance (CMR) were performed within 1 week interval. The correlations between echocardiographic parameters and right ventricular ejection fraction (RVEF) derived from CMR as well as hemodynamics were analyzed.

RESULTS

Thirty patients were enrolled including 24 with idiopathic PAH, 5 with PAH associated with connective tissue diseases and 1 with hereditary PAH. All echocardiographic parameters except right ventricular myocardial performance index (RVMPI) correlated significantly with RVEF (tricuspid annual plane systolic excursion [TAPSE], r = 0.440, P = 0.015; tricuspid annular systolic excursion velocity [S'], r = 0.444, P = 0.016; isovolumic acceleration [IVA], r = 0.600, P = 0.001; right ventricular fraction area change [RVFAC], r = 0.416, P = 0.022; ratio of right ventricular transverse diameter to left ventricular transverse diameter [RVETD/LVETD], r = -0.649, P<0.001; RVMPI, r = -0.027, P = 0.888). After adjusted for mean right atrial pressure, mean pulmonary arterial pressure and pulmonary vascular resistance (PVR), only IVA and RVETD/LVETD could independently predict RVEF. Four echocardiographic parameters displayed significant correlations with PVR (TAPSE, r = -0.615, P<0.001; S', r = -0.557, P = 0.002; RVFAC, r = -0.454, P = 0.012; RVETD/LVETD, r = 0.543, P = 0.002).

CONCLUSIONS

The echocardiographic parameters IVA and RVETD/LVETD can reflect RVEF independently regardless of hemodynamics in patients with PAH. In addition, TAPSE, S', RVFAC and RVETD/LVETD can also reflect PVR in PAH patients.