ABC | Volume 114, Nº4, April 2020

Original Article Mejia et al. Quality, the new era of cardiovascular surgery Arq Bras Cardiol. 2020; 114(4):603-612 mortality rate (p = 0.0001). As the statistical data show, this is not only explained by the volume increase, but rather by the continuous outcome improvements, which reached, in 2019, a mortality of 2% in mitral valve surgery and of 5% in aortic valve surgery. The latter should continue to decline due to increased referral of more severe cases to transcatheter aortic valve implantation (TAVI). In the congenital surgery group, there was also a significant surgical volume reduction in the 4th period (22.7%), which may have influenced the significant increase in mortality (6.9%). However, even with a modest volume increase in the 5th period (16.1%), mortality reduced significantly (2.5%). This also reflects the continuous implementation of improvement measures by the staff and the cardiovascular surgery division which, by 2019, has already reduced mortality rates to 7% (Figure 4). For arrhythmia surgery, the 5th period was quite satisfactory because, in addition to a significant volume increase (389.5%), there was a reduction in mortality of 1.2% (p = 0.0001). On the other hand, in relation to the isolated procedures, which have been presenting an expressive increase since 2008, we compared the 4th and 5th periods. We observed that the cases of Acute Aortic Dissection Surgeries increased 66% (p = 0.1060), and mortality reduced 11.2% (p = 0.0016). In 2019, the results already reach 11% for a mean mortality in the best centers of >20%. 21 It is important to mention that several protocols were structured taking into account the best moment for the surgical approach and the standardization of the surgical technique. In CABG+ Valve surgeries, the average annual volume had a modest reduction of 22.4% (p = 0.1481). However, there was a significant mortality reduction (12.1%). In 2018, the mortality rate was 8% and, in 2019, we still have not registered any deaths due to this associated procedure. In mitral valve surgery, the average annual volume increased 34.1% (p = 0.1535), with a reduction in mortality of 6.4% (p < 0.0001). Until the first period of 2019, mortality had already reached 2%. In aortic valve surgery, the mean annual volume increased 14.6% (p = 0.1481) and there was also a significant decrease in mortality (6.7%). In 2019, mortality also followed a downward trend and is already at 5%. In the combined mitral and aortic valve repairs, the average annual volume increased 22% (p = 0.2688) and mortality reduced 11.9% (p < 0.0001). The positive mortality outcomes of the valve group is also the result of strong efforts towards the establishment of a line of care, of a multidisciplinary outpatient surgery clinic and the standardization of surgical techniques. Besides, this is a population at high risk, with 56% of rheumatic disease patients, 75% of patients in functional classes III and IV and 31% of reoperations. 22 The purpose of this analysis is to show the evolution of cardiovascular surgery in one of the centers with the greatest operative volume in South America, where > 80% 23 of the patients are assisted under Brazil's Unified Health System (SUS), which makes it a reference hospital that receives all types of patient referrals for different procedures. Unquestionably, the decrease in surgical volume in the 4th period had an impact on mortality in a context that still focused on surgical volume, because evidence shows that the improvement in mortality outcomes due to volume were replaced by improvements resuting from the CQI programs, 24,25 including at university hospitals, which would be our case, 26 and in several parts of the world. 27,28 Within the package of measures developed by the InCor through its CQI program, previously mentioned, it is worth to highlight the implementation of the InCor Checklist. This project was initiated in 2014, but it was only after 2016 that it became compulsory for all surgeries. Research projects in the area of Quality and Safety have favoured partnerships financed by the FAPESP, such as the cooperation with the Fuwai Hospital, in China, and the partnership of the REPLICCAR II with the Harvard University Department of Public Health (www.repliccar.com.br ). Undoubtedly, the greatest challenge should be sustainability and, above all, the continuous outcomes improvement. To this end, strategies that aim at reducing morbidity, optimizing processes to reduce hospital stay time and that focus on improving patient experience are required. Programs like this could be spread in Brazil, focusing on standardization and continuous structuring of good quality practices, regardless of the surgical volume. Limitations We note 3 limitations: 1) This is a unicentric and retrospective study, which would hinder the generalization of our conclusions. However, the large surgical volume and the existence of an institutional registry that improves over time help minimize this bias. 2) The lack of patient stratification based on risk makes it difficult to understand whether the decrease in surgical mortality would be more associated with a greater proportion of patients at low risk. A subanalysis of more recent periods (from 2013 to 2019) was carried out and we found a significant decrease in mortality with no differences in the surgical volume or in the risk estimated by the EuroSCORE II. 3) The CQI program was consolidated in 2016, but improvement measures date back to 2007. In fact, isolated actions can be traced back to 2007, but the formulation and structuring of the CQI program were established between 2015 and 2016. In practice, we can say that the package of measures converged in 2016, which may explain the mortality reduction in all groups. Conclusions In spite of a recent trend towards increased surgical volumes, except for CABG surgery, a significant decrease in the general surgical mortality rate and in the groups studied was evident. The consolidation of the CQI program at the InCor has been associated with the progressive decrease in surgical mortality, which corroborates the evidences, regardless of the scenario or region. After the consolidation of the CQI program, the mortality rates were close to international standards. Author contributions Conception and design of the research: Mejia OAV, Lisboa LAF, Jatene FB; Acquisition of data: Mejia OAV, Lisboa LAF, 610