The researchers also determined the LV global longitudinal strain (GLS), a predictor of mortality in patients with acute heart failure.
Results showed that, compared to controls, patients with severe PAH had RV dysfunction and LV diastolic dysfunction. These patients also exhibited greater tricuspid regurgitation severity, and right heart size with worse function.
In turn, both left atrial peak strain — a measure of left atrial and ventricular function — and LV GLS were decreased in severe PAH patients. These differences were more significant in the patients who had died, as were greater pulmonary artery systolic pressure, right heart size, and worsened RV function.
A subsequent analysis found that, unlike heart rate and blood pressure, right atrial volume index (dividing the chamber’s volume by the body surface area), RV free wall strain (previously associated with mortality in PAH patients), and LV GLS parameters all correlated independently with mortality.
Of note, when the results were stratified, an LV GLS value greater than -15% “had the greatest association with mortality,” the researchers said.
“Although PAH is predominantly a right heart disease, in our cohort of [sPAH, or severe PAH] with normal LVEF, LV GLS was independently associated with death in addition to RV and right atrial abnormalities. These findings indicate that the role of left heart dysfunction in sPAH may be under-appreciated in clinical practice,” the team concluded.
“We believe … that reduced LV GLS is clinically relevant as a high-risk marker, specifically in patients with sPAH, in whom compromised RV function alone may no longer be sufficient as a prognostic marker. Accordingly, including this parameter in the echocardiographic follow-up of these patients may be beneficial,” the researchers said.