Healing of acute myocarditis with left ventricular assist device: Morphological recovery and evolution to the aspecific features of dilated cardiomyopathy

Dilated cardiomyopathy may result from an acute myocarditis. Little is reported in vivo documenting the progression from the acute inflammatory disease to the healing phase. We describe the consecutive light and electron microscopy studies performed on five myocardial sample series in a 47-year-old female patient who was referred to our hospital with acute myocarditis. She was sustained with left ventricular assist device (LVAD) for 63 days, and then she died of cerebral hemorrhage. The first three consecutive endomyocardial biopsies (days 2,4,36 from onset) documented the acute and early healing phase of the inflammatory disease. In the last two biopsies (days 50 and 64 from onset) active inflammation and myocyte necrosis were absent. The histophatological features were those commonly observed in most patients diagnosed with dilated cardiomyopathy, namely myocyte hypertrophy, nuclear size and shape irregularities, and interstitial fibrosis. Overall, the myocyte morphology significantly improved and LVAD support likely contributed to the structural recovery. The major conclusions to be drawn from this case are: 1) the aspecific pathologic findings of dilated cardiomyopathy patients may result from an acute myocardial inflammation; 2) immediate endomyocardial biopsy in patients with clinically diagnosed myocarditis minimizes the risk of missing the diagnosis of inflammatory disease; to this aim a precise definition of "early onset" is especially needed; 3) LVAD support may contribute to the morphological recovery of severely damaged myocytes.