Background Pulmonary hypertension (PH) is one of the fatal complications in the connective tissue disease (CTD).(1) CTD-associated pulmonary hypertension (CTD-PH) is sometimes associated with left heart disease and interstitial lung disease (ILD) as well as pulmonary arterial hypertension (PAH), and treatment strategies are different among them.(2)(3)

Objectives To investigate the frequency and cause of PH due to left-sided heart disease in CTD patients.

Methods A total of 396 CTD patients having either dyspnea or lower carbon monoxide diffusing capacity (DL_CO) was performed Doppler echocardiography before and after exercise with the Master’s double two-step. Right heartcatheterization (RHC) was recommended in 120 patients (30%) who had >45mmHg of tricuspid regurgitation pressure gradient (TRPG) just after exercise Doppler echocardiography or who had unexplained dyspnea and <40% of DL_CO. A Total of 49 patients (41%) agreed to undergo RHC. One patient with severe ILD was excluded and a total of 48 (40%) patients were analyzed. The patients who were suspected to have left heart diseases underwent myocardial scintigraphy, MRI and biopsy.

Results Out of the 48 patients, 13 (27%) had ≥25mmHg of mean pulmonary arterial pressure (mPAP) by RHC. Eleven patients had borderline PH (20-24mmHg of mPAP). Three patients (23%) out of the 13 PH patients had ≥15mmHg of pulmonary capillary wedge pressure (PCWP), indicating post-capillary PH. Eight patients among borderline PH had less than 160 dynes.sec.cm^-5 of pulmonary vascular resistance (PVR) and more than 10 mmHg of PCWP, and were designated as borderline post-capillary PH. Eleven patients (46%) with post-capillary PH, both manifest and borderline, consisted of systemic sclerosis (n =6), mixed connective tissue disease (n =2), systemic lupus erythematosus (n =1), Takayasu arteritis (n =1), and microscopic polyangiitis (n =1). The clinical characteristics including the findings of exercise Doppler echocardiography failed to discriminate between PAH and post-capillary PH.

All 11 patients with PH due to left heart disease had neither abnormal coronary angiogram nor mitral valve disease, but had abnormalities of echocardiography. Nine of the 11 patients (82%) had diastolic dysfunction by echocardiography. Other abnormal finding included diastolic dysfunction by myocardial MRI in 4 (100%), decreased accumulation of myocardial scintigraphy in 3 (75%), positive for cardiac troponin T in 2 (22%). Myocardial biopsy showed myocardial fibrosis in 3 of 6 (50%).

Conclusions As high as 46% of borderline and manifest PH in CTD patients was associated with left heart diseases. Aggressive investigation for the cause of PH is required because treatment strategy is different.

References

1. Humbert M et al. Screening for pulmonary arterial hypertension in patients with systemic sclerosis: clinical characteristics at diagnosis and long-term survival. Arthritis Rheum, 2011 Nov; 63(11): 3522-30.

2. Wilson SR et el. Pulmonary hypertension and right ventricular dysfunction in left heart disease. Prog Cardiovasc Dis. 2012 Sep-Oct; 55(2): 104-18.

3. Le Pavec J et el. Systemic sclerosis-related pulmonary hypertension associated with interstitial lung disease. Arthritis Rheum, 2011 Aug; 63(8): 2456-64.

Disclosure of Interest None Declared