The Beauty of Cardiac Surgery Operations is in the Eye of the Beholder… thus Warranting Rigorous Research

Last Updated: December 08, 2021


Disclosure: No relevant disclosure
Pub Date: Monday, Dec 06, 2021
Author: Marc Ruel, MD, MPH
Affiliation: Professor, Chair and Head, Division of Cardiac Surgery, University of Ottawa Heart Institute

Cardiac surgeons must not only have confidence in their abilities, but also translate this aptitude into a feeling of trust within their teams and amongst their patients. The need for this creates a nidus for highly individualized and potentially leveraging practices, which are difficult to root in the current body of clinical research in cardiac surgery. Cardiac Surgery represents a field of medicine where the stakes and levels of operator-dependency are probably unmatched. Whereas one surgeon may be able to perform countless uneventful multivessel minimally invasive coronary bypasses or transaxillary aortic valve replacements, another surgeon may excel in conventional coronary bypass surgery or aortic valve replacement and be unable to execute a single minimally invasive heart operation. This operator-dependency creates major issues in clinical research, representing threats to both internal validity (i.e., was the study correctly executed?) and external validity (i.e., are the study results generalizable to other surgical teams?).1 In my view, for a cardiac surgeon there lies a huge gap between the holy grails of disease mechanism and the clinical experience of those who we really trust as surgeons: that gap is the paucity and the shortcomings of cardiac surgery clinical research.

Surgeons over their career become experts at gauging prognosis around their interventions. Therapies are constantly allocated according to the balance between short- versus long-term risks/benefits (e.g., choosing a biological versus mechanical prosthesis), patient profile and physical functioning (e.g., favoring a minimally invasive procedure), or surgical simplicity versus durability (e.g., Ross procedure; single versus multiple arterial coronary bypass grafts). In other words, operations are allocated as a result of perceived - though very often accurately assessed - prognosis and not along a validated schema. Randomized clinical trials are necessary in cardiac surgery because no post-hoc analysis can ever account for bias at the inception of the surgical plan, or confounding-by-indication.2 The scientific statement by Gaudino et al. provides a number of very important and practical guiding principles to achieve high-quality randomized clinical trials in cardiac surgery.

The decision to undergo a heart operation, for the patient, is a proposition between the risk (both of having and not having surgery), invasiveness, and discomfort of surgery, versus the likelihood of symptom relief and a longer and better life. This is no small proposition to consider. Adverse events in surgery, like all procedural specialties, are open to interpretation and often underreported. Beyond the surgeon’s well-meaning affirmation of ‘I’ve done it many times and you’ll be fine’, clinical evidence is needed to provide strong assurance. Cardiac Surgery is also undergoing a transformation towards less invasive approaches, which are admittedly more difficult for the surgeon and team.3 Observational outcomes of such attempts to innovate and further the field should demonstrate that they are at least as safe and effective as the standard operation, and randomized trials must be undertaken to ensure that results are validated, which is currently crucially lacking in the field of minimally invasive cardiac surgery.4

Research teams must also consider that patient consent towards enrolment in cardiac surgery research may be more susceptible to fear and coercion, and take measures to mitigate such an eventuality. An aspect that is often overlooked are the potential benefits of engaging in clinical trial research for the patient, beyond purely altruistic ones. Patients enrolled in cardiovascular trials tend to fare better over the long run for reasons that may include increased scrutiny, centre expertise, and suitability resulting from a favorable risk profile. Patients might also occasionally benefit from better identification of long-term health hazards through the breadth of research follow-up.5, 6

Dr. Gaudino and colleagues provide in this Scientific Statement the necessary framework to assure the required elements of rigorous clinical evaluative science finesses the art of cardiac surgery. Their expert guidance and recommendations prove a compelling read for anyone interested in this topic.

Citation


Gaudino M, Chikwe J, Bagiella E, Bhatt DL, Doenst T, Fremes SE, Lawton J, Masterson Creber RM, Sade RM, Zwischenberger BA; on behalf of the American Heart Association Council on Cardiovascular Surgery and Anesthesia. Methodological standards for the design, implementation, and analysis of randomized trials in cardiac surgery: a scientific statement from the American Heart Association [published online ahead of print December 6, 2021]. Circulation. doi: 10.1161/CIR.0000000000001037

References


  1. Ruel M, Falk V, Farkouh ME, Freemantle N, Gaudino MF, Glineur D, Cameron DE and Taggart DP. Myocardial Revascularization Trials. Circulation. 2018;138:2943-2951.
  2. Toeg HD, Bjerre LM and Ruel M. Warfarin treatment after bioprosthetic aortic valve replacement. JAMA. 2013;309:1225.
  3. McGinn JT, Jr., Usman S, Lapierre H, Pothula VR, Mesana TG and Ruel M. Minimally invasive coronary artery bypass grafting: dual-center experience in 450 consecutive patients. Circulation. 2009;120:S78-84.
  4. Guo MH, Wells GA, Glineur D, Fortier J, Davierwala PM, Kikuchi K, Lemma MG, Mishra YK, McGinn J, Ramchandani M, Rabindra P, Nambala S, Chiu KM, Kiaii B, Gibson S and Ruel M. Minimally Invasive coronary surgery compared to STernotomy coronary artery bypass grafting: The MIST trial. Contemp Clin Trials. 2019;78:140-145.
  5. Solomon SD and Pfeffer MA. The Future of Clinical Trials in Cardiovascular Medicine. Circulation. 2016;133:2662-70.
  6. Majumdar SR, Roe MT, Peterson ED, Chen AY, Gibler WB and Armstrong PW. Better outcomes for patients treated at hospitals that participate in clinical trials. Arch Intern Med. 2008;168:657-62.

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-- The opinions expressed in this commentary are not necessarily those of the editors or of the American Heart Association --