Features of rheumatic mitral valves and a grading system to identify suitable repair cases in China.

Background: We aimed to assess the pathological characteristics of rheumatic mitral valve disease in Chinese patients and formulate a pathological grading system to identify cases suitable for rheumatic mitral valve repair (rMVP).

Methods: Nearly 5 years of follow-up data on patients who underwent rMVP were analysed. A Kaplan-Meier survival curve for freedom from reoperation and valve failure was constructed. A pathological grading system of rheumatic mitral valve lesions (PGSRMVL) was developed based on the pathological characteristics of rheumatic mitral valve disease and tested by receiver operating characteristics (ROCs) curve analysis. Predictors of endpoints for rheumatic repair were analysed.

Results: From January 2012 to June 2016, 179 patients underwent rMVP in our centre. The mean follow-up duration was 24±14 months. A left atrial anterior and posterior diameter >60 mm was an independent predictor for the 16 endpoints [hazard ratio (HR) =3.884, P=0.029]. Between 2015 and 2016, 126 consecutive pathological characteristics of rheumatic mitral valve were evaluated (61 and 65 repair and replacement cases, respectively). The ROCs area under the curve was 0.891 for the correlation between the pathological score and successful repair (cut-off point, 17.5; sensitivity, 78%; specificity, 85.2%). Seven lesions had higher ratios in the replacement group than the repair group. Commissural fusion/calcification and main chordae tendineae fusion/calcification were the most common severe pathological lesions.

Conclusions: The main pathological characteristics of rheumatic mitral valve disease in Chinese patients are commissure and sub-valvular apparatus lesions. Most patients can be appropriately treated via commissurotomy and leaflet thinning. Severe calcification of the commissure and sub-valvular apparatus can considerably decrease the odds of a successful repair. The median follow-up results of rheumatic mitral repair are considered satisfactory for the pathological characteristics in Chinese patients.