Abstract 18911: Relaxin-2 Levels and Early Myocardial Recovery in Peripartum Cardiomyopathy: Results of the Multicenter IPAC Study

Abstract

Introduction: Relaxin-2 is a polypeptide hormone which is elevated in peripartum women. Recombinant relaxin-2 is under investigation as a therapy for acute heart failure. Whether endogenous relaxin influences myocardial function in peripartum cardiomyopathy (PPCM) has not been previously investigated. We investigated the impact of relaxin-2 on recovery in PPCM in the multicenter Investigations of Pregnacy Associated Cardiomyopathy (IPAC) study. Methods: 98 women with PPCM were enrolled and serum obtained at entry. LVEF was assessed by echocardiography at entry, 2 months, 6 months and 12 months. Relaxin-2 levels were measured by ELISA. Myocardial recovery was evaluated by tertiles of relaxin at entry for the entire cohort (n=98). Given that relaxin-2 levels were most elevated early, we then reevaluated the impact of relaxin specifically in subjects enrolled in the first quartile based on days postpartum to entry. Results: Overall the cohort was 30% black 65% white and 5% other. Mean age was 30 + 6 years, LVEF 0.35 + 0.10 and time to entry 31 + 25 days post-partum. The mean relaxin level was 29 + 110 pg/ml and dropped rapidly postpartum (correlation r= -0.42, p<0.001, mean relaxin2 for post postpartum quartiles=97 + 203 (0 to 11 days), 10 + 31 (12 to 24), 4 + 2(25 to 51), 5 + 7 (51 to 95),p=0.004. For relaxin tertiles analysis for the overall cohort, subjects with the highest levels at entry had the highest mean LVEF at 2 months postpartum, (LVEF high/intermediate/low relaxin= 0.47 + 0.10/0.44 + 0.10/0.39 + 0.10,p=0.01). When reevaluated only in women presenting in the first quartile( n=25, days postpartum 6.5 +3.2 , range 0 -11 days), LVEF at 2 months was again higher in those with the highest relaxin levels (relaxin tertiles high/intermediate/low =0.53 + 0.10/ 0.45 + 0.09/0.38 + 0.11, p=0.02) with a trend at 6 months (p=0.09) and 12 months(12 month LVEF tertiles=0.55 + 0.08/ 0.53 + 0.09/0.47 + 0.14, p=0.19). Conclusions: In women with PPCM, higher relaxin-2 levels were associated with early myocardial recovery and higher LVEF at 2 months.Endogenous relaxin appears play a cardio protective role in PPCM. The role of treatment with recombinant relaxin to facilitate myocardial recovery in PPCM remains to be determined.