ABC | Volume 113, Nº4, October 2019

Original Article Cruz et al. Surgical mitral valvuloplasty in paediatric patients Arq Bras Cardiol. 2019; 113(4):748-756 The literature presents other outcome predictors that were not identified or not studied in our sample, such as ventricular dysfunction, studied by Talwar et al., 16 with HR 4,9 (95%CI 2.65–9.2), p < 0.005. On the other hand, Yakub et al. 13 described the NYHA preoperative classification, emergency surgeries and double valvular lesions as predictors of early death. In our country, rheumatic disease is the main cause of acquired heart diseases in childhood and adolescence, unlike in developed countries, where Kawasaki disease is the most frequent cause of acquired heart disease in the paediatric age group. 19,20 In this context, degenerative lesions are the main indications of mitral valve repair, which justifies the small number of studies found, taking into account only valvular corrections by MVP technique for valve sequela due to chronic RHD in the pediatric age group. 21 Although Brazil is considered a high risk country for RF, with 40% of heart surgeries being performed for valve repairs due to chronic RHD sequelae, according to data from the Department of Informatics of the Unified Health System (DATASUS), 5 only a few Brazilian studies were found involving the theme addressed in the present study, and only one of them comprising the paediatric age group, all focusing on surgical results. Murad et al. 7 studied 86 patients with a mean age of 35.8 years and concluded that MVP can be performed with low mortality and should be the procedure of choice in patients with MI. Similarly, Pomerantzeff et al. 22 studied 330 patients with a mean age of 26.9 ± 15.4 years for 20 years and concluded that the MVP technique is feasible in rheumatic patients with low early and late mortality. Severino et al., 15 in a study with 104 adult patients (mean age 32.73 ± 14.74 years) evaluating MVP results in rheumatic patients, found that late reoperation was associated with postoperative residual MI (p < 0.001), presence of PH (p < 0.01), age (p < 0.04) and postoperative functional classification (p < 0.001). Silva et al. 11 evaluated the outcome of valve reconstruction in rheumatic lesions in 40 patients younger than 18 years after 4 years of evolution and did not find statistically significant risk factors that could interfere with the evolution of patients in relation to valve replacement before 4 years. The studied variables included: functional classification in the pre- and postoperative period, amount of drugs used by patients at the time of surgery, duration of CPB and anoxia and need for VAD in the immediate postoperative period. To date, no study has been published in the North and Northeast Regions involving patients with chronic RHD, although the socioeconomic characteristics of these regions are strong factors for a higher prevalence of chronic RHD in the country. In the Brazilian articles published by Severino et al. 15 and by Silva et al. 11 there is no report of the origin of the patients operated by the MVP technique, nor were they intended to look for possible predictors for other unfavourable outcomes besides reoperation and mortality. Because the surgical indications for mitral repair in the paediatric population do not have well-defined criteria in the literature, they require previous discussions and interaction between paediatric cardiologists, cardiologists and cardiac surgeons in order to delineate and minimize factors that may contribute to a postoperative period in the short, medium and long term with good results. This is a pioneer study, due to the characteristics already described, in an exclusively paediatric population, in a high-risk region for chronic RHD, which should elicit new discussions regarding the topic addressed. Because this pathology has the special characteristic of being one of the rare rheumatic diseases whose etiologic agent is known and, therefore, has a specific treatment and can be avoided with the adoption of low-cost preventive measures with high effectiveness. Being the primary prophylaxis performed with low-cost and easily accessible antibiotics, valve sequelae and, consequently, cardiac surgeries could be avoided, reducing cost to society and improving the quality of life for the affected population. Conclusion The time of VAD use was an independent predictor for outcomes studied postoperatively. Residual MI was associated with reoperation, while TI and PH were associated with unfavourable outcomes in the immediate and late postoperative period. The data in this study allow new investigations to improve the prognosis of children and adolescents with chronic RHC submitted to the MVP repair technique. Study limitations The limitations of our study are related to its retrospective nature, sample size, and due to it being carried out in a single centre. Author contributions Conception and design of the research and Analysis and interpretation of the data: Cruz RCC, Cordeiro BS, Santos FS, Fernandes CR, Gama JMA, Ladeia AMT; Acquisition of data, Statistical analysis and Writing of the manuscript: Cruz RCC, CordeiroBS, Santos FS, Fernandes CR, Gama JMA; Critical revision of themanuscript for intellectual content: Cruz RCC, Ladeia AMT. Potential Conflict of Interest No potential conflict of interest relevant to this article was reported. Sources of Funding There were no external funding sources for this study. Study Association This article is part of the thesis of master submitted by Renata Cristina Castro Cruz, from Escola Bahiana de Medicina e Saúde Pública. Ethics approval and consent to participate The Escola Bahiana de Medicina e Saúde Pública Research Ethics Committee approved this study together with CAAE from 64019316.0.0000.5544. 754