The Prognostic Role of SYNTAX Score in Moderate Ischemic Mitral Regurgitation Puzzle

Reply by the Authors of the Original Article: SYNTAX Score and Left Ventricular Reverse Remodeling after Bypass

I have read the article entitled “Surgical Repair of Moderate Ischemic Mitral Regurgitation—A Systematic Review and Meta-analysis” by Anantha Narayanan et al,[1] recently published in this journal, with great interest. The investigators reported that concomitant mitral valve surgery for moderate ischemic mitral regurgitation (MR) at the time of surgical revascularization does not support the addition of mitral valve replacement/repair to standard coronary artery bypass grafting (CABG) surgery. This approach is associated with no demonstrable benefit in terms of hard clinical endpoints, such as stroke, early or long-term mortality, or surrogate markers of ventricular remodeling. Further research should focus on identifying subgroups of patients with moderate ischemic MR who may benefit from mitral surgery with CABG, such as those with large areas of infarct without viable myocardium who would theoretically not be expected to benefit from revascularization alone.[1]

Secondary MR is caused by progressive left ventricular remodeling and dilatation after myocardial injury and has been estimated to affect 1.6 to 2.8 million people in the United States.[2] Synergy between Percutaneous Coronary Intervention with TAXUS and Cardiac Surgery (SYNTAX) score is an angiographic scoring system and is widely used to evaluate the severity and complexity of coronary artery disease (CAD).[3] SYNTAX score has been found to be independently associated with left ventricle geometry. The severity and complexity of CAD progressively change from normal geometry to abnormal shape.[4] So, it can be thought that left ventricular remodeling might be parallel to the severity of CAD. Recently, Obeid et al[5] have revealed that SYNTAX score II is feasible and significantly prognostic in CAD patients undergoing percutaneous mitral valve repair using the MitraClip, hence widening its clinical utility in valvular heart disease.

In this context, correlation of this systematic review and meta-analysis' results[1] with SYNTAX score may shed light on further studies due to association between SYNTAX score and left ventricular remodeling.

• References

• 1 Anantha Narayanan M, Aggarwal S, Reddy YN. , et al. Surgical repair of moderate ischemic mitral regurgitation—a systematic review and meta-analysis. Thorac Cardiovasc Surg 2017; DOI: 10.1055/s-0036-1598012. [Epub ahead of print]
• 2 Heart and Stroke Statistical Update. Available at: www.americanheart.org ; Accessed August 28, 2016
• 3 Sianos G, Morel MA, Kappetein AP. , et al. The SYNTAX Score: an angiographic tool grading the complexity of coronary artery disease. EuroIntervention 2005; 1 (02) 219-227
• 4 Uçar H, Gür M, Börekçi A. , et al. Relationship between extent and complexity of coronary artery disease and different left ventricular geometric patterns in patients with coronary artery disease and hypertension. Anatol J Cardiol 2015; 15 (10) 789-794
• 5 Obeid S, Attinger-Toller A, Taramasso M. , et al. SYNTAX score II in patients with coronary artery disease undergoing percutaneous mitral repair with the MitraClip. Int J Cardiol 2017; 236: 375-380