Cardiac Findings in Patients with Systemic Sclerosis Associated Pulmonary Arterial Hypertension.
Jennifer E Pogoriler, Stephen L Archer, Stuart Rich, Lin Piao, Aliya N Husain. University of Chicago Medical Center, IL
Background: Isolated pulmonary arterial hypertension (PAH) associated with systemic sclerosis (SSc-PAH) has a poor prognosis. Survival is significantly worse than for patients with idiopathic PAH (IPAH). We previously found that SSc-PAH patients had a greater involvement of pulmonary arterioles and capillaries compared to IPAH patients and patients with other connective tissue disease-associated PAH (CTD-PAH). The poor prognosis of SSc-PAH could reflect either these pulmonary vascular factors or a relative inability of the right ventricle to adapt to increased pressures. This could be due to increased cardiac fibrosis or altered vascularity in SSc.
Design: We reviewed the cardiac histology and gross descriptions from 6 autopsy cases of SSc-PAH, 5 cases of IPAH, 5 cases of PAH associated with other types of connective tissue disease (CTD-PAH), and 8 controls. We quantified left and right ventricular interstitial and total fibrosis using a trichrome stain with an automated imaging system. We constructed a tissue microarray and quantified capillary density following immunohistochemistry for CD31.
Results: There was no significant difference among heart weights or right ventricular thickness among PAH patients of different etiologies, but all groups were heavier and thicker than controls. One SSc-PAH case had focal thickening of the intramyocardial vessel walls and patchy subendocardial fibrosis, but there were no other signs of cardiac involvement by systemic sclerosis. SSc-PAH patients tended to have more fibrosis in both the left and right ventricles, but the difference was not significant. Unlike IPAH and CTD-PAH patients, SSc-PAH patients had a significantly lower capillary density in both the right and left ventricles than control hearts (p<0.05). Unexpectedly, IPAH patients had a significantly higher capillary density in the left ventricle compared to all other groups.
Conclusions: We found no convincing evidence that patients with SSc-PAH have increased fibrosis relative to other types of PAH to explain poor survival. However, there were differences noted in capillary density among the groups which could affect ventricular function. These findings warrant further studies.
Monday, February 28, 2011 9:30 AM
Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 3, Monday Morning