RV Dyssynchrony by Speckle Tracking Strain in Pulmonary Arterial Hypertension: Will This Outcome Variable Take Root?

Right ventricular structure and function after novel repair of common arterial trunk

Objectives

In an attempt to enhance applicability and outcomes of corrections of common arterial trunk, we have recently described a novel method of correction based on the concept of morphodynamism, and preserving the structure of the right ventricle. The intermediate influence of this operation on right ventricular (RV) structure and function have not been described.

Methods and results

Thirty eight Patients (age: 1-12 months) underwent the novel repair. There were 2 early and 4 late deaths. All patients underwent early CT scans, 12 had repeat CT and 8 had MRI after 1 year or more from the operation. Detailed computerized analysis of the RV size, shape, pattern of contraction and function was performed. The shape and size were preserved, at the second investigation, with no evidence of dilatation of the neo-RV outflow, which appeared to contribute to overall function of the RV. The directional pattern of contraction showed enhanced longitudinal and radial contributions with minimal twisting. The movement of the RV free wall and septum were almost equal, with normal shape of the septum. The instantaneous pattern of contraction followed a consistent peristalsis sequence with significant contraction of both the body and the neo-outflow. The pulmonary regurgitant fraction, at follow up, varied from 22% to 42% (30 ± 6%) with preserved RV to pulmonary artery ventriculo-arterial coupling.

Conclusion

The size, shape and pattern of contraction of the RV following the novel common arterial trunk repair appears to be well preserved in the intermediate term.

5-Year prognostic value of the right ventricular strain-area loop in patients with pulmonary hypertension

Aims

Patients with pre-capillary pulmonary hypertension (PH) show poor survival, often related to right ventricular (RV) dysfunction. In this study, we assessed the 5-year prognostic value of a novel echocardiographic measure that examines RV function through the temporal relation between RV strain (ϵ) and area (i.e. RV ϵ-area loop) for all-cause mortality in PH patients.

Methods and results

Echocardiographic assessments were performed in 143 PH patients (confirmed by right heart catheterization). Transthoracic echocardiography was utilized to assess RV ϵ-area loop. Using receiver operating characteristic curve-derived cut-off values, we stratified patients in low- vs. high-risk groups for all-cause mortality. Kaplan–Meier survival curves and uni-/multivariable cox-regression models were used to assess RV ϵ-area loop’s prognostic value (independent of established predictors: age, sex, N-terminal pro B-type natriuretic peptide, 6-min walking distance). During follow-up 45 (31%) patients died, who demonstrated lower systolic slope, peak ϵ, and late diastolic slope (all P < 0.05) at baseline. Univariate cox-regression analyses identified early systolic slope, systolic slope, peak ϵ, early diastolic uncoupling, and early/late diastolic slope to predict all-cause mortality (all P < 0.05), whilst peak ϵ possessed independent prognostic value (P < 0.05). High RV loop-score (i.e. based on number of abnormal characteristics) showed poorer survival compared to low RV loop-score (Kaplan–Meier: P < 0.01). RV loop-score improved risk stratification in high-risk patients when added to established predictors.

Conclusion

Our data demonstrate the potential for RV ϵ-area loops to independently predict all-cause mortality in patients with pre-capillary PH. The non-invasive nature and simplicity of measuring the RV ϵ-area loop, support the potential clinical relevance of (repeated) echocardiography assessment of PH patients.