Evidence of subclinical right ventricular ischemia in patients with systemic sclerosis: Mechanistic insights from oxygen sensitive cardiovascular magnetic resonance imaging.

Abstract

Background: Myocardial fibrosis is the pathological feature of primary heart involvement in systemic sclerosis (SSc-pHI) and is thought to result from repeated focal ischemia due to microvasculo[1]pathy. Right ventricular (RV) dysfunction is common is SSc and typically arises from increased pulmonary arterial load due to pulmonary artery hypertension (PAH). Oxygen sensitive cardiac magnetic resonance imaging (OS-CMR) directly visualises in-vivo myocardial deoxygenation and subsequent ischemia. We aimed to detect RV myocardial ischemia in SSc to better characterise sub[1]clinical RV microvasculopathy using RV-targeted OS-CMR imaging. Methods: SSc patients without known cardiac disease, patients with stable PAH of any aetiology and normal healthy volunteers (NV) were prospective enrolled. All patients underwent a 3T CMR. The primary outcome was change in inferior RV OS-CMR signal intensity (SI). Results: A total of 46 patients (26-SSc, 10-PAH, 10-NV) were enrolled. The RV OS-CMR SI was significantly lower in the SSc group compared to the NV group (10.56±9.32 vs 20.80±5.94, p=0.001). There was no significant difference between the PAH and SSc groups (9.02±14.40 vs 10.56±9.32, p=0.929), indicating a similar degree of RV ischemia in established PAH patients and SSc patients. Conclusion: SSc patients had evidence of RV Ischemia relative to NV. These findings imply that RV ischemia occurs in patients with SSc as a primary feature of the disease representing early ischemic and/or fibrosis in SSc patients. Our findings may have screening and/or therapeutic implications.