Influence of different aetiologies on clinical course and outcome in patients with dilated cardiomyopathy.

Background: The clinical phenotype dilated cardiomyopathy is assumed to be the endstage of a multifactorial aetiopathogenetic pathophysiology which includes a not satisfactorily defined group of patients with inflammatory cardiomyopathy.

Methods: Within the German Competence Network Heart Failure patients with heart failure due to dilated cardiomyopathy of viral/inflammatory (DCMi/v) and nonviral/noninflammatory (DCM) aetiology were enrolled. After 1 year 237 patients (180 male/57 female) were re-examined including complete clinical work-up. The association of different clinical courses with the time from initial diagnosis of heart failure (newly: ≤ 1 year; late: > 1 year) was investigated.

Results: After 1-year-follow-up New York Heart Association (NYHA) class (by -0.48 in newly diagnosed DCM and -0.82 in newly diagnosed DCMi/v in addition to -0.24 in late diagnosed DCM and -0.17 in late diagnosed DCMi/v) as well as left ventricular ejection fraction (+14% in newly diagnosed DCM and DCMi/v and +6% in later diagnosed DCM and DCMi/v) were significantly improved in all patients. In patients with early diagnosed dilated cardiomyopathy a strong improvement of NYHA class could be demonstrated.

Conclusions: This study demonstrates for the first time a significant interaction between duration of disease, NYHA class and left ventricular ejection fraction in patients with DCM. Our results clearly demonstrate that in patients with DCM an early diagnosis within 1 year after occurrence of clinical signs is associated with a strong improvement in the clinical course, whereas late diagnosis results in a loss of change in clinical course and outcome.