D-Dimer and Pulmonary Arterial Hypertension in Systemic Sclerosis
Songsak Kiatchoosakun MD*, Wichai Ungkasekvinai MD*, Chaiyasit Wonvipaporn MD*, Pyatat Tatsanavivat MD*, Chingching Foocharoen MD**, Siraphop Suwannaroj MD**, Ratanavadee Nanagara MD**
Affiliation : * Division of Cardiology, Department of Medicine, Khon Kaen University, Khon Kaen ** Division of Allergy Immunology and Rheumatology, Department of Medicine, Khon Kaen University, Khon Kaen
Background : Micro-vascular thrombus is a common pathological finding in pulmonary artery hypertension.
The association between plasma D-dimer, a marker of thrombus formation, and pulmonary artery hyperten-
sion (PAH) in patients with systemic sclerosis is unknown.
Objective : To assess the correlation of the level of plasma D-dimer and pulmonary artery pressure in patients
with systemic sclerosis.
Materials and Methods : One hundred and twenty nine patients with systemic sclerosis between 19 and 75 years
of age (mean, 48 + 11.3) entered the study. Plasma D-dimer was determined using immunoturbidimetric assay
(D-dimer plus, Dade Behring Inc., Newark, USA). Pulmonary artery pressure was estimated by Doppler
echocardiography. PAH was considered present if the Doppler echocardiography-estimated right ventricular
systolic pressure (RVSP) exceeded 36 mmHg.
Results : Forty-seven patients (36.4%) had PAH according to Doppler echocardiography including 32 (68.1%)
mild (RVSP, 36-45 mmHg), nine (19.1%) moderate (RVSP, 46-55 mmHg), and six (12.8%) severe PAH (RVSP
> 56 mmHg). No significant correlation was found between plasma D-dimer and RVSP (r = 0.02, p = 0.82).
Conclusion : The present study demonstrated that the D-dimmer level is not associated with the level of
pulmonary artery pressure in patients with systemic sclerosis, indicating that microvascular thrombosis may
not play a significant role in the pathogenesis of PAH in patients with systemic sclerosis.
Keywords : D-dimer, Pulmonary hypertension, Systemic sclerosis
