Case-control study reveals overlapping coronary and microvascular alterations in systemic sclerosis, suggesting compensatory vasodilatory mechanisms preserve arteriolar function.
Key Points
To characterize the clinical distribution of cardiac manifestations and identify the physiological mechanisms driving coronary microvascular impairment in systemic sclerosis.
Screened 120 patients with systemic sclerosis using non-invasive assessments to select 17 individuals alongside 17 control subjects.
Performed right heart catheterization and intracoronary pressure-wire-guided coronary angiography to evaluate coronary flow reserve (CFR) and index of microcirculatory resistance (IMR).
In the suspected pulmonary arterial hypertension (PAH) cohort, PAH occurred in 12/20 and coronary stenosis in 9/20; in the suspected coronary artery disease (CAD) cohort, PAH occurred in 2/10 and stenosis in 6/10.
Patients with reduced CFR displayed accelerated baseline coronary flow velocity (p < 0.05), whereas hyperemic IMR did not differ significantly from those with normal CFR (p = 0.292) or controls (p = 0.308).
Coronary flow velocity in systemic sclerosis patients positively correlated with baseline IMR (r = 0.56, p = 0.019).