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Abstract

We appreciate the comments of Dr Lawrite [1Lawrie G.M. Use of “maximal regurgitant area” as the sole parameter for evaluation of severity of recurrent mitral regurgitation after mitral valve repair: importance of the American Society of Echocardiography guidelines.Ann Thorac Surg. 2012; 93 (letter): 2119-2120Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar] regarding our recent article [2Shimokawa T. Kasegawa H. Katayama Y. et al.Mechanisms of recurrent regurgitation after valve repair for prolapsed mitral valve disease.Ann Thorac Surg. 2011; 91: 1433-1439Abstract Full Text Full Text PDF PubMed Scopus (35) Google Scholar], and we thank the editor for giving us the opportunity to reply. We agree with the authors that maximal regurgitant area underestimates the severity of mitral regurgitation after mitral valve repair due to eccentric jets in patients with leaflet prolapse. In our study, the echocardiographic examination focused on abnormalities of the operated mitral valve leaflets, including thickening, sclerosis, and valvular prolapse, degree of atrial and ventricular chamber enlargement, diameter of the aorta and pulmonary artery, and fractional shortening of the left ventricle. Color-flow Doppler mapping was used to assess mitral regurgitation. Over the course of our study, we did not routinely perform quantitative echocardiography to assess the severity of mitral regurgitation. In the early period, echocardiography was used for semiquantitative assessment of mitral regurgitation in most patients according to maximal regurgitant area. This assessment was done using established techniques that represented the standard of care at that time. Although quantitative echocardiography has been performed routinely in our hospital since 2005, it is not standard practice in most other echocardiography laboratories. In addition, all patients with late reoperation underwent transesophageal echocardiography and angiography before surgery. Serial examinations have clearly demonstrated that hemodynamic function may be influenced by increased severity of mitral regurgitation. In our study, the severity of recurrent mitral regurgitation was carefully determined by serial follow-up of cardiac chamber remodeling and the patient's clinical course as well as the measurement of maximal regurgitant area. Therefore, we believe that this integrative and serial approach should result in a more accurate estimation of the severity of mitral regurgitation. The echocardiographic quantification of mitral regurgitation severity is sometimes challenging, and both qualitative and quantitative evaluations are necessary. This combined approach helps to minimize the effects of technical and measurement errors. Several parameters should be assessed and considered together for the quantification of mitral regurgitation severity. These parameters can be categorized into structural changes, Doppler echocardiographic parameters such as regurgitant jet area, vena contracta, and flow convergence (PISA), and quantitative parameters such as effective regurgitant orifice area, regurgitant volume, and regurgitant fraction [3Zoghbi W.H. Enriquez-Sarano M. Foster E. et al.Recommendations for the evaluation of the severity of native valvular regurgitation with two-dimensional and Doppler echocardiography.J Am Soc Echocardiogr. 2003; 16: 777-802Abstract Full Text Full Text PDF PubMed Scopus (3305) Google Scholar]. In addition, echocardiography allows assessments of pulmonary arterial pressure and left ventricular size and function, which are all important to assess the severity of mitral regurgitation. It is also important to distinguish between the amount of mitral regurgitation and its hemodynamic consequences. Therefore, it is essential that the severity of mitral regurgitation be correlated with the patient's symptoms and clinical presentation. Use of “Maximal Regurgitant Area” as the Sole Parameter for Evaluation of Severity of Recurrent Mitral Regurgitation After Mitral Valve Repair: Importance of the American Society of Echocardiography GuidelinesThe Annals of Thoracic SurgeryVol. 93Issue 6PreviewI read with interest the report of Shimokawa and colleagues [1] regarding the mechanisms of recurrent mitral regurgitation after surgical mitral valve repair. The authors state that the severity of mitral regurgitation in their study was assessed by measurement of the “maximum regurgitant jet area (MRA).” The authors quote a paper in which they had previously evaluated the MRA against angiographic severity of mitral regurgitation (MR). Unfortunately this method has come to be regarded as unreliable as the sole measure for severity of MR, particularly when the regurgitant jet or jets are eccentric. Full-Text PDF