Abstract 3002: Left Ventricular Diameter Predicts Recovery in Acute Cardiomyopathy: Results of the IMAC 2 Trial
Introduction : The incidence of spontaneous clinical improvement in acute cardiomyopathy (ACM) patients treated with evidence based medical therapy is unknown. We hypothesized that pts without LV dilatation at presentation would have the greatest potential for recovery of ejection fraction (EF).
Methods: A multi-center NHLBI sponsored trial, Intervention in Myocarditis and Acute Cardiomyopathy II (IMAC 2) was designed to study the clinical course of ACM and the mechanisms associated with outcomes. A clinical, echocardiography, and genetics core lab are established.
Results: 15 centers have enrolled 215 pts, mean age 45 ± 14 yrs, 34% female, NYHA class I–IV% 18/54/21/7, baseline EF 0.25 ± 0.09. Therapy included 80% beta blockers and 92% ACE or ARB treated. All patients enrolled had symptoms for ≤ 6 mos and were diagnosed with acute, idiopathic cardiomyopathy or myocarditis. Baseline and 6 mo echoes in 140 pts reviewed by the core lab demonstrated increased ejection fraction (EF): 0.25 ± 0.09 to 0.40 ± 0.11 p<0.001; mean increase 0.15 ± 0.10. Recovery in EF from baseline to 6 mos was related to LVEDD at baseline as shown in the Figure⇓. Kaplan Meier survival n=207 at 1 and 2 years 96% and 94% and transplant free survival at 1 and 2 yrs 92% and 91%.
Conclusions: Results of IMAC 2 reveal a marked spontaneous improvement in EF over 6 months, greatest in those with non-dilated LVEDD at baseline, and excellent overall survival in ACM pts treated with evidence based therapies.