In previous studies we showed that prevalence of myocardial fibrosis as assessed by late enhancement on cardiac MRI in SSc patients is 45% and is associated to diffuse disease (dcSSc) and lower left ventricle ejection fraction; microvascular damage defined as decreased perfusion on cardiac MRI after adenosine infusion, was also very frequent (79%). Our aim was to identify baseline characteristics associated to the development of cardiovascular outcomes (heart failure, coronary artery disease, arrhythmias, vasculopathy, elevated systolic pulmonary artery pressure and death) in SSc patients with previously documented myocardial fibrosis and microvascular damage.
We included 62 SSc patients who participated in the study of prevalence of myocardial fibrosis (2008-2010) and in our local SSc cohort. We performed baseline clinical evaluation, cardiac MRI, coronary CT angiography, transthoracic echocardiogram, and yearly clinical and cardiovascular evaluation that included Medsger's severity scale items, electrocardiogram, echocardiogram, chest X-ray or HRCT and spirometry; we registered presence and severity of internal organ involvement and cardiovascular outcomes. Ordinal variables were analyzed using Chi square test and Fisher test when appropriate, numeric variables were compared using Student's t-test or Mann Whitney U when appropriate, logistic regression and Cox proportional hazard ratio were used to perform multivariable analysis.
We obtained follow-up information from 62 patients (29 dcSSc, 33 lcSSc), mean follow-up was 43.5 months. Multivariable analysis showed that elevated basal ultrasensitive CRP was associated to mortality (p = 0.004, OR: 11.9, 95% CI 2.1-65.7) and recurrent digital tip ischemic ulcers (p = 0.001, OR 26.8, 95% CI 3,9-181.3) on follow-up. Myocardial fibrosis, particularly in the middle segments (p = 0.01, OR: 11.49, 95% CI 1.6-83), and older age (p = 0.02, OR: 1.11, 95% CI 1.01-1.22) were associated to heart failure on follow-up. Higher maximum mRSS was associated to coronary artery disease (p = 0.02, OR: 1.2, 95% CI 1.02-1.38), while insertion point fibrosis (p = 0.001, OR: 12.5 95% CI 2.7-56.6) was associated to recurrent digital tip ischemic ulcers.
This study shows that myocardial fibrosis, elevated ultrasensitive CRP, and higher maximum mRSS are independent predictors of cardiovascular outcomes in SSc patients. Future studies should focus on early preventive and therapeutic strategies for this group of patients.