Assessment of sub clinical right ventricular ischaemia using oxygen sensitive cardiac Magnetic Resonance Imaging in patients with systemic sclerosis.

Abstract

Background: Cardiac involvement in Systemic Sclerosis (SSc) ranges from subclinical to life-threatening. Although Pulmonary Artery Hypertension (PAH) is well described, left ventricular (LV) myocardial ischemia may also underpin some clinical manifestations. Oxygen Sensitive Cardiovascular Magnetic Resonance (OS-CMR) imaging can directly visualise in-vivo myocardial de-oxygenation. Our objective was to assess de-oxygenation using LV OS-CMR in SSc patients with no known cardiac disease. Methodology: SSc patients with no prior cardiac disease were prospectively enrolled. Age and sex matched normal volunteers (NV) were also enrolled. All patients underwent 3T CMR protocol including cine images, native T1 mapping, rest/stress OS-CMR, rest/stress perfusion, and LGE. The primary outcome was change in LV OS-CMR signal intensity (SI) between SSc and NV. Two experienced independent reviewers performed the CMR analysis (inter-assessor correlation coefficient 0.8, 95% Cl [0.3, 0.9]). Results: A total of 36 subjects (n=26 SSc, n=10 NV) were enrolled. There was significantly lower global LV OS-CMR signal intensity (SI) in the SSc group compared with the age-matched normal controls (12.8±8.2 vs 16.4±6.4, p=0.043). Twenty (77%) SSc patients had an OS-CMR SI change of 10% or less in at least one myocardial segment. Twelve (46%) had global OS-CMR SI change of at least 10% or less. Five (19%) of SSc patients presented with LGE in the LV. Eighteen (69%) of SSc patients obtained at least one abnormal T1 mapping segment in the LV (1254.0±38.0 vs 1225.7±55.5, p=0.022). Neither the SSc nor NV participants displayed significant LV hypertrophy. Conclusion: SSc patients demonstrate sub clinical left ventricular microvascular ischemia compared to normal controls, in the absence of significant LV hypertrophy.