Background: Idiopathic pulmonary arterial hypertension (IPAH) is increasingly being diagnosed in patients of advanced years. We sought to investigate observed vs expected mortality among geriatric IPAH patients treated with specific pulmonary arterial hypertension (PAH) therapy.
Methods: From the University of Connecticut's Pulmonary Vascular Disease Program database, 20 IPAH patients over 65 years of age were identified. Patient demographics, cardiopulmonary hemodynamics, PAH therapy, and mortality were retrospectively analyzed. Based on observed follow-up time, the probability of death was calculated for each subject using a prediction formula for PAH patients developed by the National Institutes of Health (NIH). Byar's method for Poisson counts was used to compare observed and expected tallies of deaths within the study sample. A P value < or = 0.05 was considered statistically significant.
Results: The mean age of the 20 geriatric IPAH patients was 77 years (+/- 6.6) of which 70% were female. The mean cardiopulmonary hemodynamic values for the cohort were: right atrial pressure: 10 mmHg (+/- 4); mean pulmonary artery pressure: 45 mmHg (+/- 9); pulmonary artery occlusion pressure: 11 mmHg (+/- 3); cardiac output: 4.1 L/min (+/- 1.2); cardiac index: 2.3 L/min (+/- 0.5); and pulmonary vascular resistance: 712 dynes / sec / cm-5 (+/- 319). Fourteen subjects received PAH monotherapy with bosentan, sildenafil, or epoprostenol. Six subjects received PAH combination therapy with bosentan, sildenafil, iloprost, or treprostinil. Total follow-up across the 20 subjects was 58.7 years, with average follow-up of 2.9 yrs (+/- 1.7) per subject. Based upon the NIH formula, the expected number of deaths for this cohort was 9.4. During follow-up, three deaths actually occurred. Thus, observed mortality was only 31.9% of expected (P = 0.03, 95% C.I. = [6.4%, 93.2%]).
Conclusion: Geriatric patients are increasingly being diagnosed with IPAH. Efficacy of PAH therapy in geriatric patients is unknown. In this cohort of subjects, the outcomes of older adults treated with specific PAH therapy demonstrates improved survival relative to that predicted by the NIH formula.