Abstract 17280: Cardiac Magnetic Resonance Imaging Identifies Severity of Cardiac Involvement in Systemic Sclerosis
Introduction: Systemic sclerosis (SSc) is characterized by vascular dysfunction and excessive fibrosis of the skin and internal organs, including the heart. At autopsy, myocardial fibrosis is seen in half of SSc patients despite patent coronary arteries, and cardiac death is 5-15 times more common in SSc patients with myocardial fibrosis than those without.
Hypothesis: We hypothesized that extracellular volume fraction (ECV), a noninvasive marker of diffuse myocardial fibrosis measured by cardiac magnetic resonance imaging (CMR), correlates with other clinical markers of SSc disease severity.
Methods: 44 SSc patients underwent right heart catheterization (RHC) for pulmonary artery systolic pressure and pulmonary vascular resistance; pulmonary function testing (PFT) for forced vital capacity and diffusing capacity for carbon monoxide; and measurement of modified Rodnan Skin Score (mRSS) by clinicians blinded to the CMR results. We calculated left ventricular (LV) myocardial ECV = [[Unable to Display Character: ∆]]R1myocardium/[[Unable to Display Character: ∆]]R1blood * (1- hematocrit), where R1 = 1/T1 and [[Unable to Display Character: ∆]]R1 is post-contrast - pre-contrast R1.
Results: ECV correlated with mRSS (R = 0.49; p < 0.001), but did not correlate significantly with SSc disease duration (DD), PFT measures of interstitial lung disease (ILD) or RHC measures of pulmonary vascular disease (PVD). There was no significant correlation for: mRSS versus DD, PFT, or RHC; DD versus PFT or RHC; and PFT versus RHC.
Conclusions: In patients with SSc, myocardial fibrosis measured by ECV correlates with skin involvement but not with DD, ILD, or PVD. That the relationship between ECV and mRSS was fair, and that other markers of SSc severity lacked correlation suggests that involvement of different organ systems occur independently of each other. ECV holds promise for noninvasively measuring myocardial fibrosis in SSc, which portends a worse prognosis, develops independently from other organ involvement, and has previously required invasive endomyocardial biopsy.
Author Disclosures: A. Patel: None. R. Burt: None. S. Shah: None. B. Benefield: None. X. Han: None. D. Lee: None.
This research has received full or partial funding support from the American Heart Association.
- © 2014 by American Heart Association, Inc.