Objective: To determine the echocardiographic characteristics and impact on survival of pulmonary hypertension (PH) and correlations between echocardiographic and clinical variables in patients with pulmonary Langerhans cell histiocytosis (PLCH).
Patients and methods: Of 123 adults seen at our institution between January 1976 and December 2002 with histologically proven PLCH, 17 underwent echocardiographic evaluation. Correlations were performed between echocardiographic measures of PH and clinical variables. Cumulative survival probabilities for patients with PH were estimated using the Kaplan-Meier method and were compared to a historical cohort of patients with PLCH using time-dependent proportional hazard regression.
Results: Of the 17 patients, PH (estimated pulmonary artery systolic pressure [PASP] at rest, > 35 mm Hg) was present in 15. Thirteen patients (6 men; median PASP, 67 mm Hg; range, 41.2-90.6 mm Hg) had no other known causes of PH. All patients were smokers. Nine patients had a PASP of more than 50 mm Hg. An inverse correlation was found between the forced vital capacity and PASP (r = -0.61; P = .03); no correlation was found between PASP and other pulmonary function parameters. Seven patients with a PASP greater than 65 mm Hg had an enlarged right ventricle with impaired systolic function. The development of PH in patients with PLCH was associated with increased mortality (hazard ratio, 22.8; 95% confidence interval, 7.6 to > 68.9; P < .001).
Conclusion: Severe PH occurs in PLCH, correlates with the forced vital capacity, and has a significant impact on survival. Clinicians should consider echocardiographic screening for PH in all dyspneic patients with PLCH.