'CLAS' score: an objective tool to standardize and predict mitral valve repairability.

Purpose: Carpentier's classification has been used to classify both stenotic and regurgitant lesions. However, given the extreme variability of lesions, a universal nomenclature suggestive of the complexity and the prognosis of the repair procedure for the entire spectrum of the mitral valve disease still remains elusive. We present the predictors of mitral valve repairability with the help of a four-level-based 'CLAS' scoring system.

Methods: A total of 394 patients undergoing mitral valve procedure were prospectively studied. The valvular apparatus was divided into four sub-units, namely Commissures (C), Leaflet (L), Annulus (A), and Subvalvular apparatus (S), and the components were scored individually and the summation scores were calculated. Based on our results, three CLAS groups were formulated.

Results: A total of 376 ( = 394) patients underwent successful MVRep (95.43%; on-table failure in 18 patients). A total of 276 were rheumatic, 51 degenerative, 28 congenital, and 16 had infective endocarditis. Thirty-day mortality was 14 (3.72%) while delayed re-intervention rate was 8 (2.12%). The mean follow-up period was 30 months. One hundred percent patients with a CLAS score ≤ 8 had a successful repair as compared to 93.33 and 69.69%, respectively, for patients with scores between 9 and 12 and > 12, respectively. The cardio pulmonary bypass time, aortic-cross-clamp time, and ICU stay also showed a significant correlation with the patient's 'CLAS' groups.

Conclusion: The CLAS score is highly predictive of a successful repair. We thus propose that, in the patients with a score of ≤ 8, repair should always be attempted irrespective of the pathology. The patients expected to be scored > 8 should be referred to a repair reference center.