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We thank Drs Pocar and Passolunghi [1Pocar M. Passolunghi D. Functional mitral regurgitation repair: earlier is better (letter).Ann Thorac Surg. 2018; 105: 1859-1860Abstract Full Text Full Text PDF Scopus (1) Google Scholar] for their interest in our work [2Kamperidis V. van Wijngaarden S.E. van Rosendael P.J. et al.Restrictive mitral valve annuloplasty: prognostic implications of left ventricular forward flow.Ann Thorac Surg. 2017; 104: 1464-1470Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar] evaluating the association between left ventricle (LV) forward stroke volume after surgical mitral valve repair for secondary mitral regurgitation and all-cause mortality. Restrictive mitral annuloplasty with complete surgical rings undersized by two sizes has been demonstrated effective in patients with secondary mitral regurgitation and dilated LV. However, significant tethering of the mitral leaflets caused by severe dilation of the LV and displacement of papillary muscles posterior and apically has been independently associated with increased risk of mitral regurgitation recurrence at follow-up [3Ciarka A. Braun J. Delgado V. et al.Predictors of mitral regurgitation recurrence in patients with heart failure undergoing mitral valve annuloplasty.Am J Cardiol. 2010; 106: 395-401Abstract Full Text Full Text PDF PubMed Scopus (141) Google Scholar]. Accordingly, surgical ventricular restoration or cardiac support devices such as the CorCap (Acorn Cardiovascular, St. Paul, MN) have been proposed as important additional procedures to ensure durable surgical mitral valve repair and improve LV systolic function [4Braun J. Ciarka A. Versteegh M.I. et al.Cardiac support device, restrictive mitral valve annuloplasty, and optimized medical treatment: a multimodality approach to nonischemic cardiomyopathy.J Thorac Cardiovasc Surg. 2011; 142: e93-e100Abstract Full Text Full Text PDF PubMed Scopus (17) Google Scholar, 5Pocar M. Di Mauro A. Passolunghi D. et al.Predictors of adverse events after surgical ventricular restoration for advanced ischaemic cardiomyopathy.Eur J Cardiothorac Surg. 2010; 37: 1093-1100Crossref PubMed Scopus (28) Google Scholar]. Patient selection is crucial to identify the patients who will benefit from surgical mitral valve repair in terms of symptoms, LV remodeling, LV function, and prognosis. Left ventricular ejection fraction, one of the main factors to select patients for surgical mitral valve repair, may not be an accurate reflector of the LV systolic function in this group of patients as it represents a change in total LV volume and does not take into account whether the direction of the blood flow is regurgitant or forward. Mitral valve repair eliminates the volume overload, and as a result, the LV ejection fraction may remain unchanged or even reduced. In contrast, LV forward stroke volume after mitral valve repair provides a better reflector of the true LV systolic function because it is a direct measurement of the volume pumped into the aorta. Our study demonstrated that successful surgical mitral valve repair for secondary mitral regurgitation improved the LV hemodynamics with increased LV forward stroke volume and reduced pulmonary arterial systolic pressure without changes in LV ejection fraction [2Kamperidis V. van Wijngaarden S.E. van Rosendael P.J. et al.Restrictive mitral valve annuloplasty: prognostic implications of left ventricular forward flow.Ann Thorac Surg. 2017; 104: 1464-1470Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar]. Whether surgical ventricular restoration could have further improved LV forward stroke volume could not be answered by the present data owing to the limited number of patients undergoing this procedure. Importantly, LV forward stroke volume at discharge was the only hemodynamic variable independently associated with overall survival. How to identify the patients who will have improved LV forward stroke volume after successful mitral valve repair needs to be investigated in additional studies. Drs Kamperidis, Delgado, and Bax disclose a financial relationship with Biotronik, Medtronic, and Boston Scientific. Functional Mitral Regurgitation Repair: Earlier Is BetterThe Annals of Thoracic SurgeryVol. 105Issue 6PreviewKamperidis and colleagues [1] are to be commended for outlining the predictive role of early postoperative left ventricular (LV) forward stroke volume on late outcome after functional mitral regurgitation (MR) repair with a restrictive ring. Baseline transaortic flow has been reported to predict late death and recurrent MR after LV restoration and MR correction [2], reflecting the detrimental effects of backward flow and MR in dilated cardiomyopathy [3, 4]. The authors focused on death and a major morbidity-and-mortality composite end point, rather than relapsing MR, and stated that associations of changes in LV hemodynamics with survival has not been investigated. Full-Text PDF