Background: Distinct morphologies of the right ventricular (RV) longitudinal strain-time curve can be observed in patients with pulmonary arterial hypertension (PAH). We aimed to quantitatively explore the curve morphology and its clinical relevance.

Methods: We studied 48 incident patients with idiopathic or hereditable PAH from a German centre diagnosed between 2014 and 2019. Longitudinal strain-time curves of the RV free wall were generated from speckle tracking echocardiographic images. Peak systolic strain negativity and three characteristics of the strain-time curve obtained from its first derivative were recorded.

Results: At baseline, peak systolic strain negativity correlated with systolic downward turn and with the early diastolic return of the strain-time curve. Initiation of targeted PAH therapy influenced peak systolic strain negativity, systolic downward turn and early diastolic return of the curve. Thirteen mortality events occurred after a median observational time of 2.9 years. Based on receiver operating characteristics, peak systolic strain negativity (area under the curve [AUC] 0.68), systolic downward turn (AUC 0.70) and early diastolic return (AUC 0.78) significantly discriminated 3-year survival status after follow-up assessments. In univariate Cox regression models, peak systolic strain negativity and early diastolic return were significantly associated with survival.

Conclusion: Further quantification of the morphology of the RV free wall strain-time curve, particularly during the early diastolic phase, may allow for the identification of clinically relevant parameters.