The right ventricular (RV) strain(ϵ)-area loop can independently predict 5-year all-cause mortality in patients with precapillary pulmonary hypertension (PH), a study in the European Heart Journal – Cardiovascular Imaging suggests.
The study included 143 patients with precapillary PH who underwent transthoracic echocardiography at a single university medical center in the Netherlands between 2003 and 2017. The transthoracic echocardiography assessments were used to examine the RV ϵ -area loop. Patients were stratified in low- vs high-risk groups for all-cause mortality, which were based on receiver operating characteristic curve-derived cut-off values for RV end diastolic area, RV end systolic area (RVESA), RV fractional area change (RVFAC), and tricuspid annular plane systolic excursion.
The independent prognostic value of the RV ϵ-area loop was assessed in Kaplan-Meier survival curves and multivariable Cox-regression models. Only the prognostic value independent of age, sex, N-terminal pro-B-type natriuretic peptide, and 6-minute walking distance (6MWD) was assessed.
Approximately 31% (n=45) of patients died during a median follow-up period of 60 months. Overall, the 5-year survival was 69%. Patients who died were older, were mostly men, and had lower baseline values for systolic slope, peak ϵ, late diastolic slope, and 6MWD (P <.05 for all). According to the multivariable models, significant predictors of 5-year all-cause survival included RVESA (>16.9 cm2), RVFAC (<25.55%), and peak ϵ (>-14.45%). The RV loop-score was associated with an improvement in risk classification, with high-risk patients with low RV loop scores experiencing better survival vs high-risk individuals with high RV loop-scores (P =.02).
A limitation of this study was the sample size, which prevented the researchers to perform analyses in subgroups of patients with different etiologies of PH.
The investigators wrote that their study findings support “the clinical potential of echocardiography-based assessment of the RV ϵ-area loop for risk stratification and survival-analyses in patients with pre-capillary PH.”
Hulshof HG, van Dijk AP, Hopman MTE, et al. 5-Year prognostic value of the right ventricular strain-area loop in patients with pulmonary hypertension [published online July 6, 2020]. Eur Heart J Cardiovasc Imaging. doi:10.1093/ehjci/jeaa143