ENDOTHELIN MAY BE PATHOGENIC IN SYSTEMIC-SCLEROSIS OF THE HEART

We evaluated 30 consecutive patients and 48 age- and sex-matched contr ols to explore the possibility of a pathogenic contribution by plasma endothelin-1 in the cardiac expression of systemic sclerosis. Venous p lasma endothelin-1 was measured by radio-immunoassay and left ventricu lar function by echocardiography. The patient group had elevated plasm a endothelin-1 (2.6+/-0.2 vs. 1.8+/-0.1 pmol/l, P<0.001), but endothel in-1 was not related to age, heart rate, blood pressure, total periphe ral resistance, disease duration or systemic sclerosis score. Endothel in-1 was related to left ventricular hypertrophy in terms of septal th ickness (r=0.33, P<0.01) and left ventricular mass index (r=0.32, P<0. 01). Plasma endothelin-1 was further related to measures indicating re duced left ventricular filling; left atrial emptying index (r=-0.50, P <0.0005), the first third tilling fraction (r=-0.31, P<0.05) and the t ime velocity integral of Doppler early/late filling velocity (r=-0.40, P<0.001). Furthermore, circulating endothelin-1 was related to impair ed left Ventricular contractility as estimated by pre-ejection period/ left ventricular ejection time (r=0.32, P<0.01) and end-systolic wall stress/volume index (r=-0.30, P<0.05). We conclude that plasma endothe lin-1 is elevated in relation to the degree of left ventricular hypert rophy, diastolic dysfunction and impaired contractility in systemic sc lerosis. It may be of pathogenic importance to the cardiac involvement in systemic sclerosis which is not mediated via an increase in system ic blood pressure. It is not yet clear whether our findings are exclus ive to systemic sclerosis patients or represent a generalized phenomen on in patients with impaired left ventricular function. (C) 1997 Elsev ier Science Ireland Ltd.