Underutilization of Perioperative Screening for Cardiovascular Events After Noncardiac Surgery in Alberta

Low-value preoperative cardiac testing before low-risk surgical procedures: a population-based cohort study

BACKGROUND

Choosing Wisely Canada (CWC) recommends avoiding noninvasive advanced cardiac testing (e.g., exercise stress testing [EST], echocardiography and myocardial perfusion imaging [MPI]) for preoperative assessment in patients scheduled to undergo low-risk noncardiac surgery. In this study, we assessed the temporal trends in testing, overlapping with the introduction of the CWC recommendations in 2014, and patient and provider factors associated with low-value testing.

METHODS

In this population-based retrospective cohort study, we used linked health administrative data in Alberta, Canada, to identify adult patients who underwent elective noncardiac surgery between Apr. 1, 2011, and Mar. 31, 2019, who had preoperative noninvasive advanced cardiac tests (EST, echocardiography or MPI) within 6 months before surgery. We included electrocardiography as an exploratory outcome. We excluded patients at high risk using the Revised Cardiac Risk Index (score ≥ 1 considered to indicate high risk), and modelled patient and temporal factors associated with the number of tests.

RESULTS

We identified 1 045 896 elective noncardiac operations performed in 798 599 patients and 25 599 advanced preoperative cardiac tests; 2.1% of operations were preceded by advanced cardiac testing. The incidence of testing increased over the study period, and, by 2018/19, patients were 1.3 times (95% confidence interval 1.2-1.4) more likely to receive a preoperative advanced test compared to 2011/12. Urban patients were more likely to receive a preoperative advanced cardiac test than their rural counterparts. Electrocardiography was the most common preoperative cardiac test, preceding 182 128 procedures (17.4%).

INTERPRETATION

Preoperative advanced cardiac testing was infrequent in adult Albertans who underwent low-risk elective noncardiac operations. Despite CWC recommendations, the use of some tests appears to be increasing, and there was substantial variation across geographic areas.

Long-term major adverse cardiovascular events following myocardial injury after non-cardiac surgery: meta-analysis

BACKGROUND

Myocardial injury after non-cardiac surgery is diagnosed following asymptomatic troponin elevation in the perioperative interval. Myocardial injury after non-cardiac surgery is associated with high mortality rates and significant rates of major adverse cardiac events within the first 30 days following surgery. However, less is known regarding its impact on mortality and morbidity beyond this time. This systematic review and meta-analysis aimed to establish the rates of long-term morbidity and mortality associated with myocardial injury after non-cardiac surgery.

METHODS

MEDLINE, Embase and Cochrane CENTRAL were searched, and abstracts screened by two reviewers. Observational studies and control arms of trials, reporting mortality and cardiovascular outcomes beyond 30 days in adult patients diagnosed with myocardial injury after non-cardiac surgery, were included. Risk of bias was assessed using the Quality in Prognostic Studies tool. A random-effects model was used for the meta-analysis of outcome subgroups.

RESULTS

Searches identified 40 studies. The meta-analysis of 37 cohort studies found a rate of major adverse cardiac events-associated myocardial injury after non-cardiac surgery of 21 per cent and mortality following myocardial injury after non-cardiac surgery was 25 per cent at 1-year follow-up. A non-linear increase in mortality rate was observed up to 1 year after surgery. Major adverse cardiac event rates were also lower in elective surgery compared with a subgroup including emergency cases. The analysis demonstrated a wide variety of accepted myocardial injury after non-cardiac surgery and major adverse cardiac events diagnostic criteria within the included studies.

CONCLUSION

A diagnosis of myocardial injury after non-cardiac surgery is associated with high rates of poor cardiovascular outcomes up to 1 year after surgery. Work is needed to standardize diagnostic criteria and reporting of myocardial injury after non-cardiac surgery-related outcomes.

REGISTRATION

This review was prospectively registered with PROSPERO in October 2021 (CRD42021283995).

High-Sensitivity Cardiac Troponin I Thresholds to Identify Myocardial Injury After Noncardiac Surgery: A Cohort Study

BACKGROUND

Myocardial injury after noncardiac surgery (MINS) is common and associated with short- and long-term major cardiovascular events. Diagnostic criteria for MINS using Abbott high-sensitivity cardiac troponin I (hs-cTnI) are unknown.

METHODS

We performed a prospective cohort study of adults who had in-patient noncardiac surgery and measured hs-cTnI (Abbott Laboratories) on postoperative serum samples collected up to postoperative day 3. The objective was to determine prognostically important hs-cTnI thresholds associated with major cardiac events and death at 30 days after noncardiac surgery. Using Cox proportional iterative analyses, we determined peak postoperative hs-cTnI thresholds associated with the occurrence of the 30-day composite of major cardiac events (ie, nonfatal myocardial infarction after 3 postoperative days, cardiac arrest, and congestive heart failure) and death.

RESULTS

Of 3953 included patients, 66 (1.7%) experienced the primary outcome at 30 days. Peak hs-cTnI values and associated incidence of major cardiac events and death were as follows: < 60 ng/L: 1.0% (95% CI 0.7-1.3); 60 to < 700 ng/L: 8.6% (5.6-13.0); and ≥ 700 ng/L: 27.3% (16.4-41.9). Compared with peak hs-cTnI < 60 ng/L, adjusted hazard ratios were 7.54 (95% CI% 4.27-13.32) for hs-cTnI values of 60 to < 700 ng/L and 26.87 (13.27-54.41) for values ≥ 700 ng/L.

CONCLUSIONS

Hs-cTnI elevation within the first 3 days after noncardiac surgery independently predicts major cardiac events and death at 30 days. A postoperative hs-cTnI ≥ 60 ng/L was associated with a > 7-fold increase in the risk of subsequent major cardiac events and mortality at 30 days.

Assessment and Correction of the Cardiac Complications Risk in Non-cardiac Operations – What's New?

Cardiovascular complications after non-cardiac surgery are the leading cause of 30-day mortality. The need for surgical interventions is approximately 5,000 procedures per 100,000 population, according to experts, the risks of non-cardiac surgical interventions are markedly higher in the elderly. It should be borne in mind that the aging of the population and the increased possibilities of medicine inevitably lead to an increase in surgical interventions in older people. Recent years have been characterized by the appearance of national and international guidelines with various algorithms for assessing and correcting cardiac risk, as well as publications on the validation of these algorithms. The purpose of this review was to provide new information about the assessment and correction of the risk of cardiac complications in non-cardiac operations. Despite the proposed new risk assessment scales, the RCRI scale remains the most commonly used, although for certain categories of patients (with oncopathology, in older age groups) the possibility of using specific questionnaires has been shown. In assessing the functional state, it is proposed to use not only a subjective assessment, but also the DASI questionnaire, 6-minute walking test and cardiopulmonary exercise test). At the next stage, it is proposed to evaluate biomarkers, primarily BNP or NT-proBNP, with a normal level – surgery, with an increased level – either an additional examination by a cardiologist or perioperative troponin screening. Currently, the prevailing opinion is that there is no need to examine patients to detect hidden lesions of the coronary arteries (non-invasive tests, coronary angiography), since this leads to excessive examination of patients, delaying the implementation of non-cardiac surgery. The extent to which this approach has an advantage over the previously used one remains to be studied.

Prognostic value and clinical utility of NT-proBNP in acute emergency medical admissions

BACKGROUND

NT-proB-type natriuretic peptide (NT-proBNP) is a frequently utilized test in congestive cardiac failure. There is little data on its utility in unselected emergency medical admissions.

AIM

This study aims to investigate the clinical utility and prognostic value of NT-proBNP in emergency medical admissions and to determine whether such testing influenced downstream investigations and length of stay (LOS).

METHODS

We report on NT-proBNP tests performed in emergency medical admissions in a 2005/2006 and subsequent 7-year (2014-2020) retrospective cohort. We assessed 30-day in-hospital mortality with a multivariable logistic regression model. The utilization of procedures/services was related to LOS with zero-truncated Poisson regression.

RESULTS

There were 64,212 admissions in 36,252 patients. Patients with a NT-proBNP test were significantly older at 75.3 years vs. 63.0 years and had longer LOS -9.4 days vs. 4.9 days. They had higher acute illness severity and comorbidity scores. Thirty-day in-hospital mortality was higher in those with a NT-proBNP test (8.8%) vs. no request (3.2%). NT-proBNP test level was prognostic in univariate - OR 2.87 (2.61, 3.15), and multivariate analyses - OR 1.40 (1.26, 1.56). Higher NT-proBNP levels predicted higher 30-day in-hospital mortality. Multivariable thirty-day in-hospital mortality was 3.8% (3.6%, 3.9%) for those without a test, increasing to 4.9% (4.7%, 5.2%) for ≥ 250 ng/L and 5.8% (5.8%, 6.3%) for ≥ 3000 ng/L. LOS was linearly related to the total number of procedures/services performed.

CONCLUSION

NT-proBNP is prognostic in emergency medical admissions. Downstream resource utilization differed following an NT-proBNP test; this may reflect different case complexity or the 'uncertainty' surrounding such admissions.

Pro-Con Debate: Cardiac Troponin Measurement as Part of Routine Follow-up of Myocardial Damage Following Noncardiac Surgery

Elevated troponin levels within 3 days of surgery, independent of the presence of symptoms, are strongly linked to increased risk of short- and long-term morbidity and mortality. However, the value of screening with troponin measurements is controversial. The Canadian Cardiovascular Society guidelines on perioperative cardiac risk assessment and management for patients who undergo noncardiac surgery recommends measuring daily troponin for 48 to 72 hours after surgery in high-risk patients. Nevertheless, others doubt this recommendation, in part because postoperative elevated levels of troponin describe very little in terms of disease or event-specific pathogenesis and etiology, and thus, tailoring an intervention remains a challenge. This Pro-Con debate offers evidence-based data to stimulate physician understanding of daily practice and its significance in this matter, and assist in determining whether to use (Pro) or not to use (Con) this surveillance.

Beyond the revised cardiac risk index: Validation of the hospital frailty risk score in non-cardiac surgery

Frailty is an established risk factor for adverse outcomes following non-cardiac surgery. The Hospital Frailty Risk Score (HFRS) is a recently described frailty assessment tool that harnesses administrative data and is composed of 109 International Classification of Disease variables. We aimed to examine the incremental prognostic utility of the HFRS in a generalizable surgical population. Using linked administrative databases, a retrospective cohort of patients admitted for non-cardiac surgery between October 1st, 2008 and September 30th, 2019 in Alberta, Canada was created. Our primary outcome was a composite of death, myocardial infarction or cardiac arrest at 30-days. Multivariable logistic regression was undertaken to assess the impact of HFRS on outcomes after adjusting for age, sex, components of the Charlson Comorbidity Index (CCI), Revised Cardiac Risk Index (RCRI) and peri-operative biomarkers. The final cohort consisted of 712,808 non-cardiac surgeries, of which 55·1% were female and the average age was 53·4 +/- 22·4 years. Using the HFRS, 86.3% were considered low risk, 10·7% were considered intermediate risk and 3·1% were considered high risk for frailty. Intermediate and high HFRS scores were associated with increased risk of the primary outcome with an adjusted odds ratio of 1·61 (95% CI 1·50-1.74) and 1·55 (95% CI 1·38-1·73). Intermediate and high HFRS were also associated with increased adjusted odds of prolonged hospital stay, in-hospital mortality, and 1-year mortality. The HFRS is a minimally onerous frailty assessment tool that can complement perioperative risk stratification in identifying patients at high risk of short- and long-term adverse events.

Troponin Testing After Noncardiac Surgery in Ontario: An Observational Study

Background

In 2017, the Canadian Cardiovascular Society (CCS) published guidelines recommending postoperative troponin surveillance in higher-risk patients having major noncardiac surgery. The objective of this study was to evaluate the proportion of major noncardiac surgery patients that would meet recommendations for troponin testing and to assess the rates of troponin testing before guideline adoption.

Methods

We conducted a retrospective observational study of patients age 40 to 105 undergoing a subset of major noncardiac surgeries that included orthopedics, gynecology, general, urology, vascular, and thoracic surgeries in Ontario, Canada from January 1, 2010 to December 31, 2017. The primary outcomes were the proportion of patients recommended for testing based on the guidelines and rates of troponin testing within 2 days of surgery.

Results

We identified 257,704 patients who underwent noncardiac surgery. Mean age was 66.4 ± 11.9 years, and 12.4% underwent urgent surgery. Applying the CCS guidelines, 71.2% of elective surgery patients and 81.0% of urgent surgery patients would have met recommendations for postoperative troponin screening, whereas 10.8% and 27.1% received postoperative troponin testing, respectively. Most elective surgery patients met recommendations for testing based on the age criterion (54.9%), followed by diabetes (24.6%) and high-risk surgery (22.7%) criteria. Troponin testing varied substantially by types of surgery: highest for open abdominal aortic aneurisms and lowest for hysterectomies.

Conclusions

Based on the CCS guidelines, most patients undergoing the subset of surgeries assessed would have met recommendations for routine troponin testing. In contrast, routine troponin testing before guideline adoption was done infrequently in Ontario, with substantial variations based on the surgery type.

Predicting Myocardial Injury and Other Cardiac Complications After Elective Noncardiac Surgery with the Revised Cardiac Risk Index: The VISION Study

BACKGROUND

The Revised Cardiac Risk Index (RCRI) is widely used to estimate risk of cardiac complications after noncardiac surgery; its estimates do not capture myocardial injury after noncardiac surgery (MINS). We evaluated the incidence of cardiac complications including MINS across RCRI risk classes and the RCRI's ability to discriminate, before surgery, between patients who will experience these complications and those who will not.

METHODS

This was a secondary analysis of a prospective cohort study of 35,815 patients ≥ 45 years old who had elective inpatient noncardiac surgery from 2007 to 2013 at 28 centres in 14 countries. The primary outcome was a composite of MINS, myocardial infarction, nonfatal cardiac arrest, or cardiac death within 30 days after surgery. The secondary outcome was this composite without MINS.

RESULTS

The primary outcome occurred in 4725 patients (13.2%); its incidences across RCRI classes I (no risk factors), II (1 risk factor), III (2 risk factors), and IV (≥ 3 risk factors) were, respectively, 8.2%, 15.4%, 26.6%, and 40.2% (C-statistic for discrimination 0.65 [95% confidence interval 0.62-0.68]). The secondary outcome occurred in 1174 patients (3.3%) with incidences of 1.6%, 4.0%, 7.9%, and 12.9%, respectively (C-statistic 0.69 [0.65-0.72]). Thirty-five percent of primary outcome events and 26.9% of secondary outcome events occurred in patients with no RCRI risk factors.

CONCLUSION

The RCRI alone is not sufficient to guide postoperative cardiac monitoring because 1 in 12 patients ≥ 45 years of age without any RCRI risk factors have a cardiac complication after major noncardiac surgery, and most of them would be missed without systematic troponin testing.