Prognostic evaluation of congestive heart failure in patients with Duchenne muscular dystrophy--retrospective study using non-invasive cardiac function tests.

The relation between heart function and the prognosis of patients with Duchenne muscular dystrophy (DMD) was analyzed in 27 non-survivors and 40 survivors by fractional shortening (FS) of the left ventricle from M-mode echocardiogram, and by the PEP/ET ratio from the systolic time interval. The patients were divided into 5 groups; (1) patients who died of congestive heart failure (group 1), (2) those who died of congestive heart failure and respiratory failure (group 2), (3) those who died of respiratory failure (group 3), (4) those who died suddenly of undefined etiology (group 4), and (5) survivors (group 5). Data from non-invasive cardiac function tests were analyzed retrospectively for 2 years and compared at 2 years, 1 year and about 3 months before their deaths in cases of group 1, 2, 3 and 4, and the data obtained at the same period were also compared with those of survivors (group 5). The age at death in group 1 (17.3 +/- 4.9 years) was significantly younger than that in group 2 (25.3 +/- 4.2 years), however, it did not statistically differ from group 3 (19.8 +/- 3.3 years old). The values of FS in group 1 were significantly lower than those in group 3, 4 and 5 at three examinations, whereas no difference in PEP/ET was observed among them. Cardiothoracic ratio (CTR) on chest X-ray in group 1 was not significantly different from other groups in each period, but the left ventricle dilated rapidly in the terminal stage of congestive heart failure which could be more precisely detected by the M-mode echocardiogram. These results indicate that in DMD, early development of congestive heart failure was associated with a poor prognosis. FS was a most sensitive non-invasive tool in predicting the prognosis. A significant reduction in FS was detectable 2 years before death. Progression in abnormality of left ventricular dimension as well as in FS may be another useful index for evaluating the prognosis of patients dying from congestive heart failure.