Risk factors for mitral valve dysfunction, reoperation and death following repair of the primary mitral valve disease in children

BACKGROUND: After primary mitral valve (MV) repair, residual mitral valve regurgitation (MR) and recurred mitral valve stenosis (MS) are the principal occurrences. This study’s purpose is to identify the risk factors of MV dysfunction, reoperation and death following repair of primary MV diseases. METHODS: We retrospectively reviewed 98 patients (47 males and 51 females) with primary MV diseases between January 2013 and December 2021. The median age was 34 months [interquartile range (IQR), 11.4–59] for male and 24 months (IQR, 7.35–72) for female. The left ventricular ejection fraction (LVEF), the left ventricular end-diastolic volume index (LVEDVI) and left ventricular end-systolic volume index (LVESVI) were assessed to evaluate patient’s left ventricular function. Risk factors that increased the likelihood of MV dysfunction, reoperation and death after surgery were investigated. RESULTS: During the 23.5 months (IQR, 9–44.5) of follow-up, 5 (5.1%) patients died, including one early death and two late deaths (n=3; 3.9%) in the MR group and one early death and one late death (n=2; 9.1%) in the MS group. Seven (9.2%) patients in the primary MR disease group and 2 (9.1%) patients in the primary MS disease group required a second MV operation for a total reoperation rate of 9.2% (9/98). As of the most recent follow-up, 34 patients experienced MV dysfunction. No significant difference was recorded between primary MR and MS disease groups in Kaplan-Meier freedom from MV dysfunction and reoperation. Mixed MV pathology (P=0.014) acted as an independent risk factor for MV dysfunction, and ≥ moderate MR at 24 h after first surgery (P=0.014) an independent risk factor for MV reoperation. Double-orifice MV technique (P=0.002), MV reoperation (P=0.023) and severe MR at 24 h after first surgery (P=0.028) were independent risk factors for death. CONCLUSIONS: The Kaplan-Meier freedom from MV dysfunction and reoperation were comparable between primary MR and MS disease groups. A high probability of MV dysfunction was predicted due to the mixed MV pathology. Patients with ≥ moderate MR at 24 h after first surgery had a higher risk of MV reoperation. Double-orifice MV technique, MV reoperation and severe MR at 24 h after first surgery had a higher risk for death.