Coronary microvascular dysfunction in asymptomatic patients affected by systemic sclerosis - limited vs. diffuse...

Area of Science:

• Cardiology
• Rheumatology
• Vascular Biology

Background:

• Systemic sclerosis (SSc) is a connective tissue disease with potential cardiac involvement.
• Coronary microvascular dysfunction (CMD) is increasingly recognized in SSc patients.
• Stratifying CMD prevalence based on SSc subtype (limited vs. diffuse) is crucial for understanding disease progression.

Purpose of the Study:

• To determine the prevalence of coronary microvascular dysfunction (CMD) in asymptomatic patients with systemic sclerosis (SSc).
• To compare CMD prevalence between the limited cutaneous SSc (lcSSc) and diffuse cutaneous SSc (dcSSc) forms.
• To investigate the relationship between disease duration and coronary flow reserve (CFR) in SSc patients.

Main Methods:

• Observational study enrolling 19 asymptomatic SSc patients (7 dcSSc, 12 lcSSc) and 20 healthy controls.
• Coronary flow reserve (CFR) assessed using Doppler to measure diastolic coronary flow velocities in the left anterior descending artery.
• Dipyridamole infusion used to induce hyperemia; wall motion score index evaluated at baseline and stress.

Main Results:

• Mean CFR was significantly lower in SSc patients (1.96±0.62) compared to controls (2.69±0.47) (P<0.001).
• Abnormal CFR (≤2) was more prevalent in SSc patients (10/19) than controls (0/20) (P<0.001).
• dcSSc patients exhibited a higher prevalence of abnormal CFR (6/7) compared to lcSSc patients (4/12) (P=0.05), with an inverse correlation between disease duration and CFR in lcSSc.

Conclusions:

• Blunted CFR, indicative of CMD, is more frequent in early-stage dcSSc.
• CMD appears to develop later in the disease course for lcSSc patients.
• These findings highlight the importance of assessing cardiac microvascular function in SSc patients, especially those with the dcSSc subtype.