PURPOSE: Background: Survival of patients with primary pulmonary hypertension (PPH) is based on the National Institute of Health (NIH) registry developed over 20 years ago at a time when there were no pulmonary artery hypertension (PAH)-specific therapies. Based on the results of the NIH registry, an equation that uses initial hemodynamic parameters (mean right atrial pressure, mean pulmonary artery pressure, and cardiac index) was developed and has since been used to estimate PAH survival. Hypothesis: The NIH survival equation is not predictive in the current era.
METHODS: We included patients (pts) with idiopathic or familial PAH (formerly PPH) referred to our center between 1982 and 2006. Vital statistics were collected by chart review and query of the Social Security Death Index. For patients on conventional therapy (diuretics, warfarin and digoxin) only at the time of referral, similar to the NIH registry, we compared rates of actual survival with predicted survival calculated using the NIH equation.
RESULTS: 276 pts were identified; the mean age at diagnosis was 45±14 years and 75% were female. At the time of referral, 36% were on warfarin, 44% were on diuretics, and 17% were on digoxin. 154/276 (56%) died on follow-up. For patients who were on conventional therapy alone at the time of referral (N=261), the median survival time was 5.3 (interquartile range 2.7 - 8.8) years, and the 1-, 3-, and 5-year actual survival rates were better than estimated survival calculated based on the NIH equation (Table).
CONCLUSION: The NIH equation is not an adequate predictor of survival in idiopathic or familial PAH patients in the current era.
CLINICAL IMPLICATIONS: New methods of risk prediction are necessary for patients with PAH.
DISCLOSURE: Thenappan Thenappan, None.