[The clinical analysis of pulmonary arterial hypertension in connective tissue disease]

To investigate the clinical features and prognosis of pulmonary arterial hypertension (PAH) secondary to connective tissue disease (CTD).

Eighty-two patients diagnosed as having CTD associated PAH (CTDaPAH) were retrospectively analyzed among 2189 patients with CTD in Peking Union Medical College Hospital between January 1997 and September 2004.

Eighty-two (3.7%) patients (75 females and 7 males), aged 41 years, were found to have CTDaPAH. The underlying diseases included mixed CTD (MCTD), systemic scleroderma, primary Sjogren's syndrome (pSS), systemic lupus erythematosus (SLE), undifferentiated CTD, dermatomyositis and Behcet disease. PAH was an earlier complication in patients with SLE or MCTD (median onset, 3 and 2 years, respectively), compared to those with pSS (6 years). The most common clinical manifestations of CTDaPAH were dyspnea on exertion (84.1%) and Raynaud's phenomenon (56.1%). The mean pulmonary artery systolic pressure (PASP) level of these patients was (65.71 +/- 20.44) mm Hg, with the decrease of PaO2 and PaCO2 level [(70.37 +/- 15.02) mm Hg, (27.88 +/- 6.46) mm Hg, respectively]. The diffusing capacity of the lungs measured using carbon monoxide was decreased [D(L)CO pred% (51 +/- 14)%]. 13%, 32%, 29% and 8% of these patients were grouped to class I, II, III and IV, respectively, on NYHA functional classification. Although the patients received treatment for underlying CTD and traditional vasodilators, the condition of elevated PASP had not been improved with the exception of a marginal decrease of PASP in SLE patients [(76.47 +/- 18.20) mm Hg --> (69.08 +/- 20.77) mm Hg]. Thirteen (15.85%) patients died during an average of 4.33 years follow-up, compared to the mortality of those with non-CTDaPAH (2.75%, P < 0.01). Lower level of PaO2 [(58.51 +/- 16.16) mm Hg] and higher proportion of NYHA class III, IV [38.46% (5/13), 30.77% (4/13), respectively] were observed in death group compared to survivors [PaO2 (73.25 +/- 14.32) mm Hg; NYHA class III, IV 34.78% (24/69), 5.80% (4/69), respectively] (P < 0.01; P < 0.05; respectively).

PAH is a common complication of CTDs, which occurs often in the forth year after initial CTD manifestations and is earlier in patients with SLE or MCTD, compared to those with pSS. The most common manifestations of CTDaPAH are dyspnea on exertion and Raynaud's phenomenon. CTDaPAH could be very severe, which will lead to lower level of PaO2 and more advanced NYHA classification, and therefore reduce the survival rate of the patients. Doppler echocardiography and lung function test are necessary to detect PAH early.