{'fraction_non_alphanumeric': 0.02244039270687237, 'fraction_numerical': 0.012903225806451613, 'mean_word_length': 5.289241622574956, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 1, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Response by Capoulade et al to Letter Regarding Article, "Impact of Left Ventricular to Mitral Valve Ring Mismatch on Recurrent Ischemic Mitral Regurgitation After Ring Annuloplasty".

Circulation. 2017;135:e785–e786. DOI: 10.1161/CIRCULATIONAHA.117.026957 March 21, 2017 e785 Romain Capoulade, PhD Michael Bowdish, MD Irving L. Kron, MD Peter Smith, MD Judy Hung, MD In Response: We thank Dr Pocar for his insightful comments regarding our study.1 Several studies focusing on mitral valve (MV) annuloplasty in patients with ischemic mitral regurgitation (IMR) have highlighted a significant recurrence rate of IMR after the procedure (>30% at 1 year).2–4 One of the main mechanisms for this recurrence is the persistence of MV leaflet tethering after restrictive annuloplasty.5 MV annuloplasty using a downsized ring size according to intertrigonal distance or anterior MV leaflet size may exacerbate posterior leaflet tethering, especially if the lateral wall of the left ventricle (LV) remains displaced relative to the posterior edge of the mitral annulus. For the same implanted ring size, the larger the size of the LV, the greater the tethering of the posterior leaflet, owing to an increased distance between the papillary muscles and coaptation surface of the posterior leaflet. This can result in exacerbation of mitral leaflet tethering, preventing adequate MV coaptation. The concept of LV-MV ring mismatch, which is calculated as a simple ratio between LV end systolic dimension (LVESd) and ring size, incorporates the underlying mechanism for recurrence of MR after ring annuloplasty as a measure of the disassociation or mismatch between LV and MV apparatus spatial relationship and takes into account abnormalities in MV tethering. In our large cohort of patients with IMR, LVESd relative to the MV ring size was the only parameter reaching the significance level to predict recurrent IMR at 1 year, suggesting a better predictive value for LVESd relative to the MV ring size as opposed to LVESd alone. These findings, in addition to the mechanistic basis linking the LV-MV ring mismatch and MV tethering, support the use of the LV-MV ring mismatch to determine patients with high risk of IMR recurrence instead of absolute LV dimensions. Although postoperative predictors are important evaluations mechanistically and prognostically, we focused on preoperative factors to help guide surgical decision making. Although our study had a relatively large cohort of patients with IMR undergoing MV repair, the statistical analysis was underpowered to provide a definitive cutoff from a receiver operator curve analysis to predict 1-year recurrence of IMR. Indeed, discrepancies, albeit relatively small, exist between commercial ring size and real external septal-lateral diameter of the ring. However, surgeons choose ring size based on the labeled ring size provided by the manufacturer rather than the ring’s real dimensions. Therefore, we used the labeled ring size to make this concept more widely applicable. In conclusion, the identification of patients most likely to benefit from MV repair is an important part of clinical decision making in the management of patients with IMR. The concept of LV-MV ring mismatch provides a quantitative and easily measurable parameter in a clinical setting to stratify the risk of recurrent IMR after restrictive annuloplasty. Response by Capoulade et al to Letter Regarding Article, “Impact of Left Ventricular to Mitral Valve Ring Mismatch on Recurrent Ischemic Mitral Regurgitation After Ring Annuloplasty”