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 2 years.

Methods: Twenty-eight IIM patients (41.9±1.6 years) without cardiovascular symptoms were enrolled. Patients with monophasic/polyphasic disease patterns 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 is characterized by reduced lateral s' (10.4 vs. 6.4 cm/s, 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 2 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/s; lateral a': 10.7±0.3, vs. 17.3±0.8 cm/s; 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 2 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 patterns. 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/s,), 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 2 years after diagnosis, which identifies them as a high-risk population. TDI is a useful method to detect echocardiographic abnormalities in IIM complementing conventional echocardiography and can recognize the high cardiac risk.