Myocardial injury after noncardiac surgery (MINS) has been recognized as a frequent postoperative complication in patients with risk factors for cardiovascular disease.
1
Despite MINS being predominantly asymptomatic, it carries a high risk of mortality within 30 days of surgery.1
The Canadian Cardiovascular Society (CCS) Guidelines on Perioperative Cardiac Risk Assessment and Management for Patients Who Undergo Noncardiac Surgery, published online in late 2016 and in print in early 2017, provide recommendations regarding screening for those at risk of MINS.2
As the translation of guideline recommendations into practice is often slow and inconsistent,3
the uptake of the CCS Guidelines within Canadian perioperative practice is unknown.In this issue of the Journal, Gouda and colleagues report on their province-wide review of the ordering of biomarkers for preoperative risk assessment and postoperative detection and management of myocardial injury in Alberta, Canada.
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Using provincial health-care administrative data for the years 2013-2017, the group focused on implementation of the CCS recommendations for: (1) preoperative brain natriuretic peptide (BNP, or the prohormone NT-proBNP) screening to enhance cardiac risk prediction; and (2) postoperative electrocardiogram and troponin screening in patients with elevated cardiac risk to detect MINS.2
Overall, the adoption of CCS recommendations into practice by physicians involved in perioperative medicine was low, as were the follow-up rates and escalation of care for elevated postoperative troponins.With evolving demographics and advances in perioperative care, an increasing number of Canadians are being considered for elective surgical procedures, despite the presence of established cardiac risk factors.
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This is reflected in their study population: 30% had a history of ischemic heart disease; the average age was 68 years; and the cohort included 20% of the patients undergoing noncardiac surgery in Alberta.4
Several large international studies have demonstrated that myocardial injury is a common and often clinically silent event during the early postoperative period, with a significant impact on survival.1
,5
The lack of overt ischemic symptoms in the majority of cases (> 85%) is a major consideration, as only one third of patients at high risk of perioperative events (as evidenced by elevated preoperative natriuretic peptide) received postoperative troponin monitoring. Of the 11,619 individuals who underwent postoperative troponin monitoring, MINS was detected in 24% of the cases (n = 2793), a clear association with increased mortality at 6 months (12.7%).Given the high rate of mortality after MINS, the authors’ efforts to examine the management of patients with elevated troponins and outcomes at 6 months adds additional insights into perioperative care. The CCS guidelines strongly recommended long-term aspirin and statin therapy after detection of MINS,
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but only a minority (7.7%) of patients with elevated troponin received a statin. Greater involvement of medical specialists in the perioperative care of MINS patients may have led to more patients receiving intensification of their medical therapy. It is encouraging to see the positive impact that specialist follow-up had on mortality (6.6% vs 13% without such follow-up, odds ratio = 0.488). However, only 10% of patients with elevated troponin were followed by a cardiology/internal medicine service. We support the position of the authors that the first step toward improving outcomes in this high-risk population is the development of a system to both identify and subsequently follow-up perioperative myocardial injury.The identification of patients at elevated cardiac risk has traditionally been based on clinical risk indices and assessment of functional capacity. However, a recent multicentre trial demonstrated that neither clinician-subjective assessment of functional capacity nor formal cardiopulmonary exercise testing demonstrated the prognostic accuracy required to inform perioperative risk discussion.
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Confirming the recommendations of the CCS guidelines, preoperative biomarker screening using NT-proBNP was predictive of myocardial injury at 30- day and 1-year mortality assessment.6
The CCS guidelines were the first make a strong recommendation for preoperative use of cardiac biomarkers (BNP or NT-proBNP) to enhance perioperative risk estimation in all patients ≥ 65 years old or those 45-64 years old and having a revised cardiac risk index score of ≥ 1. Gouda et al. elected to modify the target population to include patients at even higher risk of myocardial injury, by focusing only on patients > 65 years old with a revised cardiac risk index ≥ 1 or those > 45 years old with a known history of cardiovascular disease. This may explain the higher rate of troponin elevation (24%) seen in those who had postoperative monitoring. Despite the fact that all patients would have qualified for natriuretic peptide screening during the final year of the cohort study, only 7.8% underwent testing; this was not an appreciable change from baseline practice (2013). Furthermore, only one third of patients with elevated preoperative natriuretic peptide had postoperative troponin monitoring; the rate of troponin elevation in this high-risk population is not described, but one would anticipate a MINS incidence of ≥ 20% in these patients. The evidence surrounding the benefits of biomarker screening is expanding, and a recent substudy of the Vascular Events In Noncardiac Surgery Patients Cohort Evaluation (VISION) trial suggested that the threshold value predictive of MINS risk is likely lower than the threshold (NT-proBNP > 300 ng/L) referenced in the CCS guidelines and in this cohort study.7
A major strength of the work by Gouda et al. is the availability of linked administrative health databases that incorporate universal drug prescriptions and laboratory values from across all centres in the province of Alberta. The authors were able to use these data to determine timing and results of biomarker tests, as well as where the tests were carried out. For example, preoperative BNP analysis may not have been done in the testing lab of the same hospital as the surgery. In addition, the Pharmaceutical Information Network Database allowed for tracking of recommended medical therapy for patients considered to be at risk. This degree of detail is not available in all provinces; for example, in Ontario, only opioids and drugs prescribed and paid for under the Ontario Drug Benefits program in the outpatient setting are accessible.
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Finally, differences in practice patterns geographically and between academic and community centres were able to be compared.IC/ES Data Dictionary, Institute for Clinical Evaluative Studies.
https://datadictionary.ices.on.ca/Applications/DataDictionary/Default.aspx
Date: 2020
Date accessed: July 2, 2020
Administrative databases can facilitate research into clinical questions that would be impractical to study using prospective trials. Large cohorts of interest can be identified, and data generated and analyzed in a short time and at a relatively low cost. Rare events, such as intraoperative mortality, can be studied due to the availability of data from diverse populations. Health-care utilization and economic costs can also be analyzed to determine the cost-benefit balance of an intervention. On the other hand, database studies suffer from a number of well-known limitations: data are retrospective and uncontrolled, and are usually confined to a single jurisdiction or country. Missing data require imputation, and erroneous procedure, diagnostic, and billing codes are difficult to identify. In addition, definition and coding methods are regularly revised and can change during the time frame of a given study.
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,10
Associations between data may be unclear: for example, in the study by Gouda et al., the relationship between BNP testing and the surgical procedure was assumed if the test was done within 30 days before surgery. However, the high positivity rate suggests that in at least some cases testing may have been done for other reasons, such as follow-up of congestive heart failure, and thus inferring a relationship between test ordering and the surgical event is not necessarily valid. Finally, very large sample sizes yield results that are often statistically significant, but clinically irrelevant.Database research has yielded valuable information in the field of perioperative medicine.
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One of the very valuable benefits of large database research is enabling quality improvement initiatives, such as evaluating the uptake of evidence-based guidelines, as in the Gouda et al. study. Multivariate analysis of data can identify subgroups that can be targeted to identify barriers to implementation, such as educational or structural initiatives among specific groups or institutions. Gouda et al. illustrate the potential for tracking guideline implementation guidelines over time across varied clinical environments as a quality improvement tool, and, as new evidence emerges, tailored strategies for education and communication can be designed.The translation of scientific literature or of evidence-based recommendations by expert panels into clinical practice is notoriously slow.
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,12
Thus, it is not surprising that the short timeline for assessment of biomarker ordering practices in the Alberta study after publication of the CCS perioperative guidelines (< 1 year) did not show a marked improvement.4
As evidence is constantly evolving, recommendations at one point in time may become obsolete as new study results emerge. The science of knowledge translation has become a discipline of its own, with the Knowledge to Action Framework a commonly used structure to enhance uptake of evidence-based recommendations into practice.12
A cornerstone of knowledge translation is the assessment of barriers to implementation, with the development of context-specific strategies to overcome these barriers.13
Barriers to adoption of new literature have been divided into several broad categories, including personal factors, guideline-related factors, and external factors.14
Table 1 lists some common barriers to clinical implementation of guideline recommendations, and some directed strategies aimed at overcoming these barriers.Table 1Barriers and directed strategies to implementation of guideline recommendations
| Barriers to implementation | Directed implementation strategies |
|---|---|
| Personal factors | |
| Physician knowledge | Knowledge dissemination, such as continuing medical education and opinion leaders. Interdisciplinary approach, practice audits, and feedback. |
| Attitudes of health-care providers | |
| Motivation | |
| Guideline-related factors | |
| Level of evidence presented | Structured presentation, such as GRADE |
| Plausibility of recommendations | Clinical trial results |
| Complexity | Checklists, preprinted orders, flowcharts, websites, and mobile apps |
| Applicability | |
| Conflicting recommendations | Editorials, pro/con debates |
| External factors | |
| Resource limitations: personnel, funding, availability of drugs, tests, and equipment | Implementation specific to local context, advocacy |
| Time restrictions, workload factors | Efficient processes, involved leadership |
| Lack of buy-in from colleagues, such as surgeons, nurses, pharmacy, and laboratory | Interprofessional involvement in planning, problem-solving, and education |
| Insufficient support of administration | Quality improvement and cost/benefit analyses |
GRADE, Grading of Recommendations Assessment, Development, and Evaluation.
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The routine use of biomarkers in the assessment and management of high-risk patients is an important step toward identifying and reducing serious cardiovascular complications of surgery. It is likely that many of the barriers mentioned have contributed to the low implementation of the CCS perioperative guidelines in the province of Alberta. The study by Gouda et al. is an important step in devising strategies to ensure that the best possible evidence is being employed in perioperative practice; a follow-up audit 3 years after publication of the CCS guidelines would be relevant and informative.
Funding Sources
The authors have no funding sources to declare.
Disclosures
Dr Parlow served as co-chair and Dr McMullen sat on the primary panel for the Canadian Cardiovascular Society Guidelines on Perioperative Cardiac Risk Assessment and Management for Patients Who Undergo Noncardiac Surgery. The authors have no conflicts of interest to disclose.
References
- The Vascular Events In Noncardiac Surgery Patients Cohort Evaluation (VISION) Study Investigators. Association between postoperative troponin levels and 30-day mortality among patients undergoing noncardiac surgery.JAMA. 2012; 307: 2295-2304
- Canadian Cardiovascular Society Guidelines on Perioperative Cardiac Risk Assessment and Management for Patients Who Undergo Noncardiac Surgery.Can J Cardiol. 2017; 33: 17-32
- Improving adherence to cardiovascular guidelines: realistic transition from paper to patient.Exp Rev Cardiovasc Ther. 2020; 18: 41-51
- Underutilization of perioperative screening for cardiovascular events after noncardiac surgery in Alberta.Can J Cardiol. 2021; 37: 57-65
- Effects of extended-release metoprolol succinate in patients undergoing non-cardiac surgery (POISE trial): a randomised controlled trial.Lancet. 2008; 371: 1839-1847
- Assessment of functional capacity before major non-cardiac surgery: an international, prospective cohort study.Lancet. 2018; 391: 2631-2640
- Preoperative N-terminal pro–B-type natriuretic peptide and cardiovascular events after noncardiac surgery.Ann Int Med. 2019; 172: 96-104
- IC/ES Data Dictionary, Institute for Clinical Evaluative Studies.(Available at:)https://datadictionary.ices.on.ca/Applications/DataDictionary/Default.aspxDate: 2020Date accessed: July 2, 2020
- International Classification of Diseases, 10th Revision, Clinical Modification.(Available at:)
- Potential impact of changes in administrative database coding methodology on research and policy decisions: an example from the Ontario Health Insurance Plan.Can J Anesth. 2020; 67: 487-488
- Big data—and its contributions to peri-operative medicine.Anaesthesia. 2014; 69: 95-110
- Lost in knowledge translation: Time for a map?.J Contin Educ Health Prof. 2006; 26: 13-24
- Adapting clinical practice guidelines to local context and assessing barriers to their use.CMAJ. 2010; 182: E78-E84
- Barriers and strategies in guideline implementation—a scoping review.Healthcare. 2016; 36: 1-16
Article Info
Publication History
Published online: December 09, 2020
Accepted:
July 21,
2020
Received:
July 6,
2020
Footnotes
See article by Gouda et al., pages 57–65 of this issue.
See page 13 for disclosure information.
Identification
Copyright
© 2020 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.
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- Underutilization of Perioperative Screening for Cardiovascular Events After Noncardiac Surgery in AlbertaCanadian Journal of CardiologyVol. 37Issue 1
- PreviewPerioperative myocardial injury after noncardiac surgery affects more than 10% of individuals, with increased morbidity and mortality. Perioperative cardiac risk assessment targets the identification of this high-risk population using preoperative natriuretic peptides and postoperative troponin measurements. Our objective was to assess the use of these biomarkers in the province of Alberta.
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