The Prognostic Value of Right Atrial Strain Imaging in Patients with Pre-Capillary Pulmonary Hypertension

Abstract Background Right ventricular (RV) failure in patients with pulmonary hypertension (PH) is associated with unfavorable clinical events and a poor prognosis. Elevation of right atrial (RA) pressure is established as a marker for RV failure. However, the additive prognostic value of RA mechanical function is unclear. Materials and Methods We tested the hypothesis that RA function by strain echocardiography has prognostic usefulness by studying 165 consecutive patients with pre-capillary PH defined invasively: mean pulmonary artery pressure ≥ 25mmHg and pulmonary capillary wedge pressure 15 mmHg. Speckle tracking strain analyses of the RA and RV were performed, along with routine measures. Peak RA strain values from 6 segments using generic speckle-tracking software were averaged to RA peak longitudinal strain, representing RA global reservoir function. The primary endpoint was all-cause mortality during 5 years of follow-up. RA strain was similarly analyzed in a control group of 16 normal subjects for comparison. Results There were 151 PH patients (aged 55±16 years, 73% women, World Health Organization functional class 2.6±0.6), after 14 exclusions (3 atrial septal defects and 11 with left ventricular ejection fraction Conclusions RA peak longitudinal strain had additive prognostic usefulness to other clinical measures including RV strain, RA area, and RA pressure in patients with PH. RA mechanical function by strain imaging has potential for clinical applications in PH patients.