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.