Relapse in patients with non-ischemic dilated cardiomyopathy and improved ejection fraction managed with medical therapy.

Background: Relapse is an important problem in nonischemic dilated cardiomyopathy (DCM) patients with improved left ventricular ejection fraction (LVEF). This study aimed to determine the long-term outcomes of patients with non-ischemic dilated cardiomyopathy and improved ejection fraction and analyse the risk of relapse in patients being managed with medical therapy.

Methods: This was a single-centre, retrospective, observational study of all adult patients with non-ischemic DCM enrolled in a cohort. Patients with improved LVEF defined as LVEF <40% at baseline who showed improvement of LVEF to a level ≥40% with an absolute increase in LVEF of ≥10% while on medical therapy were included and followed-up till end of study period.

Results: Of the 548 patients in the non-ischemic DCM group, 131 (23.9%) had an improved LVEF. Of these, 72 (55%) patients had sustained improvement, while 59 (45%) relapsed during follow-up. In the relapsed group, 7 (11.9%) patients had discontinued drug therapy. Relapse occurred at a median duration of 57 months (range 8-224 months) after improvement of LVEF. Of the total patients who had improved LVEF, 3.8% relapsed by 1 year, 23.7% by 5 years and 37.4% by 10 years.

Conclusion: In this non-ischemic DCM cohort 23.9% patients improved their LVEF. Of these, 45% relapsed. Risk of relapse persists over long-term with nearly 50% patients relapsing more than 5 years after their improvement in LVEF. Diabetes mellitus and higher left ventricular internal diameter in diastole at improvement were independent predictors of relapse.