Systemic sclerosis is associated with coronary microvascular dysfunction assessed using echocardiographic coronary flow parameters: a meta-analysis

Systemic sclerosis (SSc) is a connective tissue disease that is characterized by vascular dysfunction and extensive fibrosis. The current literature suggests a 15-35% prevalence of cardiac manifestations in patients with SSc, the majority of which remains subclinical. Patients with SSc often demonstrate angiographically normal epicardial coronary arteries despite underlying dysregulation in the coronary microvasculature. Coronary flow reserve (CFR) is a noninvasive marker of coronary microvascular circulation.

This meta-analysis aimed to compare CFR between patients with SSc and healthy controls.

A comprehensive literature search of the major bibliographic databases, including PubMed/MEDLINE, Embase, and the Cochrane Library was conducted. The aim was to identify studies comparing CFR between patients with SSc and healthy controls. The standardized mean differences (SMDs) with 95% confidence intervals (CIs) were pooled using an inverse-variance random-effects model. Statistical significance was set at p < 0.05. Heterogeneity was assessed using the Higgins I2 metric.

Four studies were included in this meta-analysis, with a total of 210 participants (129 patients with SSc; 81 healthy controls). In the SSc and control groups, 88.3% and 70.3% of the patients, respectively, were female. The mean ages of the SSc and control group were 52.2 ± 13.2 and 47.77 ± 9.8, respectively. The pooled analysis demonstrated a statistically significant reduction in CFR associated with SSc [SMD: -1.44; 95% CI: -1.76, -1.13; p<0.00001] compared to healthy controls. No heterogeneity was observed in the effect estimates [I2 = 0%].

SSc is associated with a higher risk of coronary microvascular dysfunction, as indicated by the reduced CFR. The results of this meta-analysis demonstrate the importance of a comprehensive cardiac evaluation in patients with SSc. Early aggressive targeted interventions for impaired CFR in SSc patients may lead to improved clinical outcomes. Further prospective studies are required to elucidate the prognostic impact of a blunted CFR.

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