Commentary: Trends and patterns: The devil is in the details

Abstract

Central MessageTrends and outcomes of cardiac surgery in the UK show significant reduction in all-cause mortality. This is despite an increase in the risk profile and complexity of procedures.See Article page 259. Trends and outcomes of cardiac surgery in the UK show significant reduction in all-cause mortality. This is despite an increase in the risk profile and complexity of procedures. See Article page 259. In this issue of the Journal, Grant and colleagues1Grant S.W. Kendall S. Goodwin A.T. Cooper G. Trivedi U. Page R. et al.Trends and outcomes for cardiac surgery in the United Kingdom from 2002 to 2016.J Thorac Cardiovasc Surg Open. 2021; 7: 259-269Google Scholar report on the trends and outcomes for cardiac surgery over a 15-year period between 2002 and 2016 in the United Kingdom by using validated data from the UK National Adult Cardiac Surgery Audit database. Congratulations to the authors for performing linear regression analysis on 534,067 procedures to conclude that despite an increase in patient risk profile, there was a consistent reduction of in-hospital mortality from 4.0% to 2.8% in the latter years of the study. Logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) overestimates risk; the authors acknowledge that this improvement in observed to expected outcomes must be interpreted cautiously and that the risk factors required for EuroSCORE II were missing in the earlier original dataset. However, this underlines the limitations in retrospective analysis of a historical dataset, especially when the impact of diabetes, mild-to-moderate renal impairment, and multiple cardiac procedures (>2) were not scored in the older logistic EuroSCORE. In addition, patients are now operated more frequently as inpatients, minimizing the incidence of frequent myocardial infarctions and maintaining preserved left ventricular (LV) function. In the earlier years of the study, the waiting list for cardiac surgical intervention in the United Kingdom could be as long as 12 months. The impact of such delay is immeasurable and unquantifiable say, in terms of, deterioration of LV function; nonetheless, the authors do confirm a reduction in the proportion of patients with moderate or poor LV function over the time period studied. Also, the publication of surgeon-specific mortality data leading to risk aversion is difficult to appraise, but data needed to refute or substantiate this is nonexistent and its impact cannot be trivialized. So, what has driven this reduction in mortality rate, especially as the patient cohort has significantly more comorbidities? The drivers of this trend will inevitably be multifactorial. Improved preoperative and frailty assessment, multi disciplinary teams, operative techniques, postoperative management, and more availability of mechanical support are all likely to have played a role. Increasing adoption of percutaneous options may also have improved outcomes in conventional cardiac surgery and importantly to the reduction of redo procedures to 1% in the most recent year. Another significant limitation acknowledged is the absence of data on the impact of transcatheter aortic valve implantation on surgical aortic valve replacement. Finally, almost all of the risk scores have been developed largely for the coronary disease population. The authors report a decrease in the number of coronary artery bypass grafting procedures by 33.9% with an increase in the number of patients undergoing any valve surgery and isolated valve surgery by 70.7%, with the number of isolated valve procedures (aortic and mitral) up by 42.5%. This increase yet again highlights the need for a contemporaneous risk scoring system to accurately reflect such trends and outcomes. For example, LV ejection fraction of 55% is regarded as good LV function in the context of mitral regurgitation and is classified in the risk scoring systems as good despite well-established evidence base conflict, and certain procedures such as concomitant TV intervention, ablations, and complex aortic surgery are poorly risk stratified. Trends and outcomes for cardiac surgery in the United Kingdom from 2002 to 2016JTCVS OpenVol. 7PreviewCardiac surgery has evolved significantly since the turn of the century. The objective of this study was to investigate trends in cardiac surgery activity and outcomes in the United Kingdom utilizing a mandatory national cardiac surgical clinical database in the context of a comprehensive public health care system (ie, the UK National Health Service). Full-Text PDF Open Access