Clinical impact of the right ventricular diastolic patterns by speckle tracking echocardiography in idiopathic pulmonary arterial hypertension

Objectives. To explore speckle tracking echocardiographic strain patterns during right ventricular (RV) diastole and their clinical relevance in idiopathic pulmonary arterial hypertension (IPAH). Background. RV diastolic function defined by speckle tracking echocardiography remains incompletely understood Methods. In 108 consecutive IPAH patients three distinct strain-derived patterns from the mid-basal RV free wall segments were identified. Each patient underwent baseline clinical, hemodynamic and complete echocardiographic evaluation and followed-up. Results. The three strain-derived diastolic patterns were identified. Pattern 1 was characterized by prompt return of strain-time curves to baseline after peak systolic negativity, like in normal controls. Pattern 2 was characterized by persisting negativity of strain-time curves well into diastole, before an end-diastolic returning to baseline. Pattern 3 was characterized by a slow return of strain-time curves to baseline during diastole. The three patterns corresponded respectively to mild PH, more advance PH but with still preserved RV function and obvious end-stage right heart failure. Patterns were characterized by high reproducibility (Cohen's κ=0.64, p=0.0001). Multivariable models for clinical worsening prediction demonstrated that the addition of RV diastolic patterns to clinical and hemodynamic variables significantly increased the prognostic power of the model (0.78 vs 0.66; p<0.001). Freedom from clinical worsening rates at 1 and 2 years from baseline were, respectively, 100% and 93% for Pattern 1; 80% and 55% for Pattern 2; 60% and 33% for Pattern 3. Conclusions. The results of the present study suggest that using speckle tracking echocardiography we can identify three phenotypically distinct, reproducible and clinically meaningful RV strain-derived diastolic patterns.