Background: Systemic sclerosis (SSc) is a connective tissue disease characterised by vascular changes and immunologically induced fibrosis of the skin and internal organs. Systemic sclerosis may be associated with both right (RV) and left ventricular (LV) diastolic dysfunction.
Aim: To analyse RV and LV myocardial diastolic function in patients with SSc and its relation to exercise capacity.
Methods: We prospectively studied 51 consecutive patients (47 females, 4 males, age 53.3+/-15.2 years) with SSc (mean disease duration 9+/-12.4 years) and a group of 31 age-matched healthy subjects (28 females, 3 males, age 52.68+/-12.1 years). In addition to conventional investigation, transthoracic echocardiography (TTE) for assessment of RV and LV myocardial diastolic function and 6-minute walking test (6MWT) were performed.
Results: Abnormal LV filling, as expressed by an inverted mitral E/A ratio (Mit E/A <1), was detected in 28 (55%) SSc patients and in 8 (25%) controls (p <0.001). The mean value of Mit E/A in the SSc group was lower than in controls (1.0+/-0.3 vs. 1.2+/-0.3, p=0.04). There were no differences in pulmonary venous flow between SSc patients and controls. The mean value of Tei index for the LV was higher in SSc than in controls (0.44+/-0.08 vs. 0.38+/-0.05, p <0.001). Abnormal RV filling, as expressed by an inverted tricuspid E/A ratio (TR E/A <1), was detected in 16 (31%) SSc patients and in 5 (16%) controls (p <0.001). Patients with SSc were found to have an inverted Tr E/A ratio (Tr E/A <1), indicating abnormal RV filling. The mean value of Tr E/A in SSc was lower than in controls (1.0+/-0.2 vs. 1.2+/-0.3, p=0.04). The mean value of Tei index for the RV was higher in SSc patients than in controls (0.35+/-0.07 vs. 0.29+/-0.03, p <0.001). In multiple regression analysis Tr E/A ratio was independently correlated with Mit E/A ratio (r=0.65, p=0.01). The mean 6MWT distance was shorter in the SSc group than in controls (528+/-100.6 vs. 617.7+/-80 m, p <0.001) and the mean saturation of capillary blood after the 6-MWT was lower in SSc patients (92.7+/-4.9 vs. 97.2+/-1.2%, p <0.001). Mean desaturation after test and D sat was significantly more pronounced in the SSc group than in controls (3.4+/-3.1 vs. 0.7+/-0.9, p <0.001). The Tr E/A ratio and Mit E/A ratio correlated positively with 6MWT distance (r=0,49, p=0.01 and r=0.48, p=0.02).
Conclusions: Impaired RV and LV relaxation is observed in a significant percentage of SSc patients and is associated with decreased exercise capacity.