TC-99M SESTAMIBI SCINTIGRAPHIC EVALUATION OF SKELETAL-MUSCLE DISEASE IN PATIENTS WITH SYSTEMIC-SCLEROSIS - DIAGNOSTIC RELIABILITY AND COMPARISON WITH CARDIAC-FUNCTION AND PERFUSION

The diagnosis of skeletal muscle involvement in patients with systemic sclerosis (SSc) is usually based on clinical, laboratory, electromyog raphic, and bioptic evidence of muscle disorder, whereas SSc cardiac d isease is well established by nuclear medicine techniques (radionuclid e ventriculography and myocardial scintigraphy). Previous reports have retrospectively hypothesized a possible relationship between cardiac and muscle involvement in scleroderma patients. In order to improve ov erall diagnostic accuracy in the qualitative/quantitative assessment o f skeletal muscle involvement in these patients and to compare these r esults with those obtained at the cardiac level, diethylenetriaminepen taacetic acid (DTPA)-Tc-99m radionuclide ventriculography and Tc-99m S ESTAMIBI myocardial and muscular scintigraphic examinations were perfo rmed in 10 SSc patients and in five healthy subjects. Muscular radioac tivity, as assessed at thigh and calf levels by means of a segmental s core, was significantly decreased in SSc patients in comparison with h ealthy subjects (global score value 15.6 +/- 2.2 vs 22.7 +/- 1.6, p<0. 001), as well as right ventricular ejection fraction (RVEF, 34.3% +/- 5.3 vs 53.6% +/- 4.2, p<0.001) and myocardial segmental perfusion (glo bal score value, 19.6 +/- 2 vs 25.9 +/- 1.1, p<0.01). The results show a high frequency of skeletal muscle involvement in patients with SSc. Moreover, scleroderma patients with muscle disorders, as evidenced by scintigraphy, show a comparable occurrence of cardiac involvement, ev en in the absence of clinical signs of cardiac dysfunction.