Global Right Heart Assessment with Speckle-Tracking Imaging Improves the Risk Prediction of a Validated Scoring System in Pulmonary Arterial Hypertension

Background: Right ventricular (RV) function and right atrial (RA) remodeling are major determinants of outcome in pulmonary arterial hypertension (PAH). Strain echocardiography is emerging as a valuable approach for the study of RV and RA function. We sought to assess the incremental prognostic value of serial combined speckle-tracking examination of right chambers in newly diagnosed therapy-naive PAH patients. Methods: The study endpoint was a composite of all-cause mortality, hospitalizations due to worsening PAH, and initiation of parenteral prostanoids. Patients were assessed at baseline and at first revaluation after initiation of treatment. Right ventricular free-wall longitudinal strain (FWLS) and RA peak atrial longitudinal strain (PALS) were used as measures of RV and RA function. Results: Eighty-three patients were included. Mean RV-FWLS and RA-PALS were -13.9% +/- 6.1% and 23.1% +/- 11.4%. The best performing prognostic score among the Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension, French Pulmonary Hypertension Registry, and Registry to Evaluate Early and Long-Term Pulmonary Arterial Hypertension Disease Management (REVEAL) scores was the REVEAL (area under the curve = 0.79, P < .001). With the identified cutoffs, both RV-FWLS (hazard ratio for RV-FWLS < -13.2% = 0.366; 95% CI, 0.159-0.842; P = .018) and RA-PALS (hazard ratio for RA-PALS > 20% = 0.399; 95% CI, 0.176-0.905; P = .028) were independently associated with the primary outcome after correction for the REVEAL score. The combined assessment of RV-FWLS and RA-PALS in addition to the REVEAL score determined a net improvement in prediction of 0.439 (95% CI, 0.070-0.888, P = .04). At 5 months (interquartile range, 4-8) of follow-up, RV-FWLS and RA-PALS improved significantly only in patients free from the primary outcome (P < .001 and P = .001, respectively). Conclusions: The combined assessment of RV-FWLS and RA-PALS determined an improvement in outcome prediction of validated prognostic risk scores and should be considered within the multiparametric evaluation of patients with PAH.