Abstract 15926: Mechanics of Mitral Regurgitation in Peripartum Cardiomyopathy
Background: Peripartum cardiomyopathy (PCM) is an important disease often associated with myocardial recovery. The mechanisms of mitral regurgitation (MR) in PCM related to recovery are unclear.
Methods: The Investigation in Pregnancy Associated Cardiomyopathy (IPAC) was a prospective multicenter study of 100 PCM patients enrolled with ejection fraction (EF) <45% within 2 months of delivery. Baseline and 6 month echocardiograms were analyzed for EF, MR severity using current guidelines (biplane-averaged vena contracta width) and mitral valve mechanics: tenting area, annular diameter, coaptation height.
Results: Paired baseline and 6 month complete quantitative data sets were available in 65 patients. MR of at least moderate degree was present in 43% at baseline and improved to 11% at follow-up (p<0.01). EFs improved from 35.3% to 51.1%, p < 0.001 and end-diastolic volumes (EDV) improved from 139 ml to 111 ml, p < 0.001. Significant changes occurred in mitral tenting area (1.74cm to 1.37cm*) annular diameter (30.4cm to 28.9cm*) and coaptation height (8.5mm to 7.0 mm*), all *p < 0.004. MR severity reduction by vena contracta was significantly related to tenting area (r=0.62, p<0.001), mitral annular diameter (r=0.59, p<0.001), and EDV (r=0.55, p<0.001). Using a multivariable model, all 3 variables were independently associated with improvement in MR (p<0.001,p=0.017 and p=0.012, respectively). There was positive interaction observed between mitral annular diameter and tenting area (p=0.011). No significant correlation with MR and EF change alone was observed.
Conclusions: Mitral regurgitation in PCM was independently related to increases in EDV, mitral tenting area and mitral annular dilation, but not EF. These factors were reversible with myocardial recovery. Mitral annular dilation was synergistic with tenting area as contributors to MR severity. These observations have clinical implications for understanding functional MR mechanics in PCN.
- Peripartum cardiomyopathy
- Mitral regurgitation
- Mitral valve disease
- Heart failure, pregnancy
- © 2013 by American Heart Association, Inc.