Right atrial function and prognosis in idiopathic pulmonary arterial hypertension

To determine whether right atrial (RA) function has prognostic value in patients with idiopathic pulmonary arterial hypertension (PAH).

Overall, 104 patients (70 female, mean age 58±13years) with idiopathic PAH underwent standard Doppler echocardiography and strain and strain rate (SR) analysis before right heart catheterization. At a mean follow-up of 22±7months, 30 patients (29%) had clinical worsening. On Cox multivariable proportional-hazards regression analysis, RA reservoir function measured as peak longitudinal SR (hazard ratio [HR] 0.5; P<0.0001), RA area (HR 1.2; P<0.01), right ventricular (RV) SR (HR 0.6; P<0.0001), cardiac index (HR 0.79; P<0.01), and mixed venous oxygen saturation (HR 0.82; P<0.01) were found to be independent correlates of cardiac events. A RA SR reservoir cut-off value of <1.2s^-1 and a RV SR cut-off value of <1s^-1 well identified patients at higher risk of clinical worsening (sensitivity 85.5%; specificity 90.4%; test accuracy 88.8%). In particular, event rates and mean survival time free of clinical worsening were: 6.1% and 23.5±2.2months in patients with normal RA and RV SR; 45% and 20.9±5.5months in patients with impaired RA and normal RV SR; 56.2% and 17.7±6.6months in patients with normal RA and impaired RV SR; and 87.5% and 12.9±7.6months in patients with impairment of both RA and RV SR.

Our data suggest that RA function has prognostic value in idiopathic PAH, where a poorer RA function, as explored by strain and SR analysis, is associated with a worse outcome.