Epidemiology and natural history of recovery of left ventricular function in recent onset dilated cardiomyopathies

Abstract

Although the long term prognosis of patients with dilated cardiomyopathy (DCM) remains poor, approximately 25 % of DCM patients with recent onset of heart failure (< 6 months) have a relatively benign clinical course with a spontaneously improvement in symptoms and partial, or in some cases complete, recovery of left ventricular (LV) function. Despite the longstanding recognition of the clinical phenomenon of LV recovery, relatively little attention has been paid to the etiology and natural history of this important group of DCM patients. Accordingly, in the present review we will focus on the epidemiology and natural history of recent onset DCM in patients who undergo spontaneous resolution of symptoms that is accompanied by recovery of LV function.

Figure

Recovery and normalization LV function in clinical settings. Recovery of LV function, defined as an improvement in LF ejection fraction from 5 – 15% occurs in all forms of dilated cardiomyopathy reviewed. Recovery of LV function was greater for energetic defects > toxins > inflammatory etiologies. Note that data on recovery of LV function were not available in the literature for stress cardiomyopathy (CM) and chemotherapy (and hence are shown as zero). Normalization of LV function, defined as an EF ≥ 50%, occured in all forms of cardiomyopathy that were reviewed. Normalization of LV function paralleled recovery of LV function and was greater for energetic defects > toxins > inflammatory etiologies. As shown in normalization of LV structure function occurs far less frequently than does recovery LV function. (The data for this figure were obtained by averaging the data from tables 1 and 2) (Key: CM = cardiomyopathy; PPCM = post-partum cardiomyopathy; ROCM = recent onset cardiomyopathy; SIRS = systemic inflammatory response syndrome)