Accuracy of echocardiographic indices for serial monitoring of right ventricular systolic function in patients with precapillary pulmonary hypertension

Abstract

Background: Serial assessment of right ventricular ejection fraction (RVEF) predicts the clinical outcome of patients with pulmonary hypertension (PH). Cardiac magnetic resonance imaging (CMRI) enables RVEF monitoring, but its applicability is limited in clinical practice. This study aimed to examine the correlation between changes in CMRI-derived RVEF with those in echocardiographic indices in patients with precapillary PH.

Methods: CMRI and echocardiographic indices of RV systolic function were evaluated at baseline and follow-up in 54 consecutive patients with precapillary PH (pulmonary arterial hypertension (PAH), n = 23; non-PAH, n = 31). During follow-up, medical treatment was optimized according to the guidelines for PH. Using CMRI-derived RVEF as the gold standard, we examined the accuracy of five echocardiographic indices by correlation analysis and receiver operating characteristic (ROC) analysis and by calculating sensitivity, specificity, and positive and negative predictive values.

Results: After an average period of 9.5 months, CMRI-derived RVEF improved from 30.2% ± 10.6% at baseline to 41.4% ± 11.3% at follow-up. These changes significantly correlated with those in the five echocardiographic indices, i.e., %RV fractional shortening (r = 0.27), %RV area change (r = 0.46), tricuspid annular plane systolic excursion (TAPSE) (r = 0.84), RV myocardial performance index (RVMPI) (r = -0.72), and systolic lateral tricuspid annular motion velocity (TVlat) (r = 0.66). Of these indices, %RV area change, TAPSE, and TVlat significantly correlated with those of CMRI-derived RVEF in both PAH and non-PAH subgroups. ROC analysis showed that improvement in echocardiographic indices predicted a pre-specified improvement in CMRI-derived RVEF (>2.9%), with TAPSE and TVlat showing better accuracy over the other three indices.

Conclusions: Echocardiographic indices modestly correlate with the changes in CMRI-derived RVEF in precapillary PH patients. Comparison among the five echocardiographic indices revealed that TAPSE and TVlat provide better accuracy than %RV fractional shortening, %RV area change, and RVMPI.

Fig 1. Representative images of echocardiographic assessment of right ventricular systolic function.

(A) %RVFS [(a–b)/a × 100%]; (B) percentage RV area change [(a–b)/a × 100%]; (C) TAPSE; (D) right ventricular MPI [(a–b)/b]; and (E) TVlat. See text for further information on how these indices were obtained or calculated. LA, left atrium; LV, left ventricle; RA, right atrium; RV, right ventricle. Reprinted from J Am Soc Echocardiogr. 2012 Mar;25(3):280–6, Takahiro Sato et al., Validation study on the accuracy of echocardiographic measurements of right ventricular systolic function in pulmonary hypertension,[7] with permission from Elsevier.

Fig 2. Correlation between the changes in CMRI-derived RVEF and echocardiographic parameters.

There were significant correlations between the changes in CMRI-derived RVEF and those in the five echocardiographic indices. %RV area changes at baseline and follow-up were not calculated in two patients (one PAH, one non-PAH) because of poor image quality, whereas the other four echocardiographic indices were evaluated in all 54 patients. CMRI, cardiac magnetic resonance imaging; RV, right ventricular; RVEF, right ventricular ejection fraction; RVFS, right ventricular fractional shortening; TAPSE, tricuspid annular plane systolic excursion; RV MPI, right ventricular myocardial performance index; TVlat, systolic lateral tricuspid annular motion velocity.

Fig 3. Receiver operating characteristic curve analysis of the accuracy of echocardiographic parameters to detect a significant improvement in CMRI-derived RVEF.

%RV area changes at baseline and follow-up were not calculated in two patients (one PAH, one non-PAH) because of poor image quality, whereas the other four echocardiographic indices were evaluated in all 54 patients. CMRI, cardiac magnetic resonance imaging; RV, right ventricular; RVEF, right ventricular ejection fraction; RVFS, right ventricular fractional shortening; TAPSE, tricuspid annular plane systolic excursion; RV MPI, right ventricular myocardial performance index; TVlat, systolic lateral tricuspid annular motion velocity.