Subclinical systolic and diastolic myocardial dysfunction in polyphasic polymyositis/dermatomyositis: a 2-year longitudinal study

Background: Cardiac involvement in patients with idiopathic inflammatory myopathies (IIM) is associated with increased morbidity and mortality risk, however little is known about the progression of cardiac dysfunction and long term data are scarce. In the present work we intended to prospectively study echocardiographic parameters in patients with IIM for two years. Methods: 28 IIM patients (43.9±1.6 years) without cardiovascular symptoms were enrolled. Patients with monophasic/polyphasic disease pattern were studied separately and compared to age-matched healthy individuals. Conventional echocardiographic and tissue Doppler imaging (TDI) parameters of systolic [LV: ejection fraction (EF), mitral annulus systolic movement (MAPSE), lateral s') and diastolic left (mitral inflow velocities, lateral anulus velocities: e', a', E/e') and right ventricular function (fractional area change: FAC, tricuspid annulus plane systolic excursion: TAPSE) were measured at the time of the diagnosis and 2 years later. Results: Subclinical LV systolic dysfunction characterized by reduced lateral s’ (10.4 vs. 6.4 cm/sec, p<0.05), EF (62.6±0.6%, vs. 51.7±0.7%) and MAPSE (18.5±0.6 vs. 14.5±0.6 mm) could be observed in IIM patients with polyphasic disease course two years after diagnosis compared to controls. Furthermore, diastolic LV function showed a marked deterioration to grade I diastolic dysfunction at 2 years in the polyphasic group (lateral e': 12.9 ±0.6, vs. 7.4±0.3 cm/sec; lateral a': 10.7±0.3, vs. 17.3±0.8 cm/sec; p<0.05) supported by larger left atrium (32.1±0.6 vs. 37.8±0.6 mm; p<0.05]. TDI measurements confirmed subclinical RV systolic dysfunction in polyphasic patients two years after diagnosis (FAC: 45.6±1.8%, vs. 32.7±1.4%; TAPSE: 22.7±0.5, vs. 18.1±0.3 mm; p<0.05). Similar, but not significant tendencies could be detected in patients with monophasic disease pattern. Polyphasic patients showed significantly (p<0.05) worse results compared to monophasic patients regarding EF (51.7±0.7% vs. 58.1±0.6%), lateral s’ (6.4±0.4 cm/sec vs. 8.6±0.4 cm/sec,), left atrium (37.8±0.6 mm vs. 33.3±0.8 mm), FAC (32.7±1.4% vs. 41.0±1.6%) and TAPSE (18.1±0.3 mm vs. 21.3±0.7 mm). Conclusions: Significant subclinical cardiac dysfunction could be detected in IIM patients with polyphasic disease course two years after diagnosis, which identify them as a high risk population. TDI is a useful method to detect echocardiographic abnormalities in IIM complementing the conventional echocardiography and can recognize the high cardiac risk.