Pulmonary hypertension in lymphangioleiomyomatosis: characteristics in 20 patients

This retrospective, mutticentre study evaluated patients with lymphangioleiomyomatosis (LAM) and pre-capillary pulmonary hypertension (PH) by right heart catheterisation. It was conducted in 20 females with a mean +/- so age of 49 +/- 12 yrs and a mean +/- SD time interval between LAM and PH diagnoses of 9.2 +/- 9.8 yrs. All, except for one patient, were receiving supplemental oxygen. 6-min walking distance was mean +/- SD 340 +/- 84 m. Haemodynamic characteristics were: mean pulmonary artery pressure (PAP) 32+6 mmHg, cardiac index 3.5 +/- 1.1 L.min(-1).m(-2) and pulmonary vascular resistance (PVR) 376 +/- 184 dyn.s.cm(-5). Mean PAP was >35 mmHg in only 20% of cases. The forced expiratory volume in 1 s was 42 +/- 25%, carbon monoxide transfer factor was 29 +/- 13%, and arterial oxygen tension (Pa,O-2) was 7.4 +/- 1.3 kPa in room air. Mean PAP and PVR did not correlate with Pa,O-2. In six patients who received oral pulmonary arterial hypertension (PAH) therapy, the PAP decreased from 33 +/- 9 mmHg to 24 +/- 10 mmHg and the PVR decreased from 481 +/- 188 dyn.s.cm(-5) to 280 +/- 79 dyn.s.cm(-5). The overall probability of survival was 94% at 2 yrs. Pre-capillary PH of mild haemodynamic severity may occur in patients with LAM, even with mild pulmonary function impairment. PAH therapy might improve the haemodynamics in PH associated with LAM.