Value of Estimated Right Ventricular Filling Pressure in Predicting Cardiac Events in Chronic Pulmonary Arterial Hypertension

Background

Right ventricular (RV) filling pressure can be estimated using tissue Doppler imaging (TDI) from the tricuspid lateral annulus, but few data are available on the usefulness of Doppler-derived RV filling pressure in predicting the prognosis of chronic pulmonary arterial hypertension (PAH).

Methods

In 50 consecutive patients with PAH, TDI was performed within 24 hours of right-sided catheterization to measure early diastolic myocardial velocity at the tricuspid lateral annulus (E_a) and early diastolic tricuspid inflow (E). The tricuspid E/E_a ratio was calculated and compared with the invasive hemodynamic variables. Cardiac events were defined as cardiac death or rehospitalization due to RV failure.

Results

Mean right atrial pressure (RAP) averaged 6 ± 5 mm Hg (range, 1-25 mm Hg). E/E_a correlated positively with mean RAP (r = 0.80, P < .001), irrespective of RV systolic function. We divided patients into group A with cardiac events (n = 19) and group B without events (n = 31) in a mean follow-up period of 14 months. Plasma brain natriuretic peptide level and E/E_a were significantly higher in group A than in group B (349 ± 310 pg/dL vs 129 ± 136 pg/dL, P = .001; 7.0 ± 3.2 vs 4.5 ± 1.9, P = .004, respectively), whereas mean pulmonary artery pressure did not differ significantly. In a multivariate model, E/E_a remained predictive for cardiac events (hazard ratio 1.227; 95% confidence interval, 1.042-1.444; P = .014). An E/E_a cutoff value of 6.8 discriminated cases with cardiac events with a sensitivity of 42% and specificity of 97% (area under the curve 0.71).

Conclusion

The tricuspid E/E_a ratio provides a reliable estimation of RV filling pressure and predicts cardiac events in patients with PAH.

Keywords: Cardiac events, Pulmonary hypertension, Right atrial pressure, Tissue Doppler imaging