BENEFICIAL EFFECTS OF BOSENTAN ON MYOCARDIAL PERFUSION AND FUNCTION ASSESSED BY CARDIAC MAGNETIC RESONANCE IMAGING AND TISSUE DOPPLER IMAGING IN SYSTEMIC SCLEROSIS

Background: Primary myocardial involvement due to microcirculation impairment is common in systemic sclerosis. Endothelin (ET) is among the strongest endogenous vasoconstrictors and a large body of evidence suggests that ET strongly contributes to vascular dysfunction in SSc. Bosentan is a dual endothelin receptor antagonist which previously demonstrated beneficial effects in SSc vascular complications such as pulmonary arterial hypertension and digital ulcers.Objectives: The aim of this study was to evaluate the short-term effects of bosentan on myocardial perfusion and function assessed by cardiac magnetic resonance imaging (MRI) and tissue Doppler imaging (DTI) respectively in SSc patientsMethods: We prospectively evaluated 18 SSc patients without clinical heart failure and with normal pulmonary arterial pressure (13 women, mean age 54±10 years; mean disease duration 7±6 years, 10 with diffuse and 8 with limited cutaneous forms). MRI perfusion index, determined from time-intensity curves, and systolic and diastolic strain rates determined by DTI in the inferior wall were assessed at baseline after a 72-hour vasodilator washout period and repeated after 4 weeks of bosentan treatment (62.5 mg bid for 2 weeks titrated to 125 mg bid for 2 weeks).Results: Bosentan treatment led to a significant increase in MRI perfusion index (0.214±0.05 vs 0.164±0.05 at baseline; p=0.006) and in systolic and diastolic strain rates (3.02±0.65 vs 2.17±0.42 s-1 at baseline, p=0.0005 and 3.77±1.47 vs 2.85 ±1.36 at baseline; p=0.0084, respectively).Conclusion: In systemic sclerosis, a short-term treatment with bosentan simultaneously improves myocardial perfusion and function, as evaluated by highly sensitive and quantitative methods, suggesting a beneficial effect on vascular dysfunction. Whether additional remodelling effect may be observed with long-term treatment with bosentan remains to be determined.Citation: Ann Rheum Dis, volume 65, supplement II, year 2006, page 90Session: Scleroderma and related syndromes