medwireNews: Patients with pulmonary hypertension (PHT) have reduced right ventricular (RV) strain and more dyssynchronous ventricles than healthy individuals, show results of a three-dimensional speckle tracking (3D-ST) study.
Area strain (AS), in particular, had strong associations with right ventricular ejection fraction (RVEF) and mortality and may thus “be an important additional measurement in the assessment of RV systolic function in predicting outcomes”, write the study’s authors in the Journal of the American College of Cardiology.
Petros Nihoyannopoulos (Imperial College London, UK) and colleagues used 3D-ST to measure the RV free wall in 97 consecutive patients with PHT (60 with pulmonary arterial hypertension, 31 with chronic thromboembolic PHT and six with PHT secondary to left heart disease) and 60 healthy volunteers.
They found that AS, radial strain (RS), longitudinal strain (LS) and circumferential strain (CS) were all significantly lower in the patients than controls, whereas the systolic dyssynchrony index was significantly higher.
In addition, all strain vectors and the systolic dyssynchrony index significantly correlated with RVEF, with the strongest correlations observed for AS (r=-0.85) and CS (r=-0.71).
Using receiver-operating characteristic curve analysis, the researchers calculated that 24-month mortality was best predicted at cut-offs of -24.7%, -9.9%, -16.1% and 30.3% for AS, CS, LS and RVEF, respectively.
Above these cut-offs, patients with high AS, CS or LS were between 3.5 and 7.6 times more likely to die than those with lower values, while patients with a RVEF below the cut-off were 2.4 times more likely to die that those with a higher RVEF.
However, a logistic regression model incorporating tricuspid annular plane systolic excursion, RV systolic annular velocity, RVEF, age, gender and minimum AS showed that age and AS were the only independent predictors of mortality.
Nihoyannopoulos and co-authors say that “[s]peckle tracking data may help risk stratify patients with pulmonary hypertension and guide clinical management”, but they add that “current proprietary speckle tracking software has been designed for evaluation of the left ventricle.”
Therefore, “[d]evelopment of software specifically for assessment of the RV could improve the diagnostic value of this modality”, the team concludes.
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By Laura Cowen, medwireNews Reporter