Impaired Coronary Vasodilator Reserve and Adverse Prognosis in Patients With Systemic Inflammatory Disorders

Abstract

Objectives: The purpose of this study was to evaluate the prognostic value of quantitative myocardial blood flow (MBF) and myocardial flow reserve (MFR), reflecting the integrated effects of diffuse atherosclerosis and microvascular dysfunction in patients with systemic inflammatory disorders.

Background: Rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and psoriasis (PsO) are common inflammatory conditions with excess cardiovascular (CV) risk compared to the general population. Systemic inflammation perturbs endothelial function and has been linked to coronary vasomotor dysfunction. However, the prognostic significance of this vascular dysfunction is not known.

Methods: This was a retrospective study of patients with RA, SLE, and PsO undergoing clinically indicated rest and stress myocardial perfusion positron emission tomography (PET). Patients with an abnormal myocardial perfusion study or left ventricular dysfunction were excluded. MFR was calculated as the ratio of myocardial blood flow (MBF, ml/min/g) at peak stress compared to that at rest.

Results: Among the 198 patients (median age: 65 years; 80% female), 20.7% had SLE, 31.8% had PsO, and 47.5% had RA. There were no differences in mean MFR between these conditions. Over a median follow-up of 7.8 years, there were 51 deaths and 63 major adverse cardiovascular events (MACE). Patients in the lowest tertile (MFR <1.65) had higher all-cause mortality than the highest tertile, which remained significant after adjusting for age, sex, and the pre-test clinical risk score (hazard ratio [HR]: 2.4; 95% confidence interval [CI]: 1.05 to 5.4; p = 0.038). Similarly, compared to the highest MFR tertile, those in the lowest tertile had a lower MACE-free survival after adjusting for age, sex, and the pre-test clinical risk score (HR: 3.6; 95% CI: 1.7 to 7.6; p = 0.001).

Conclusions: In patients with systemic inflammatory disorders, impaired coronary vasodilator reserve was associated with worse cardiovascular outcomes and all-cause mortality.

Keywords: PET; inflammation; microvascular dysfunction; nuclear imaging.