Does cardiology intervention improve mortality for post-operative troponin elevations after emergency orthopaedic-geriatric surgery? A randomised controlled study

The effects of troponin screening among patients undergoing acute high-risk abdominal surgery: A retrospective cohort study

BACKGROUND

Acute high-risk abdominal (AHA) surgery is associated with a high short-term mortality rate. This might be partly attributed to myocardial injury after non-cardiac surgery (MINS) defined by elevated postoperative troponin levels. The myocardial injury is often asymptomatic; thus, troponin screening seems to be the best diagnostic method. We aimed to assess whether implementing troponin screening with subsequent individualised interventions as standard care is associated with reduced mortality after AHA surgery. We also explored the treatment implications in the screening period.

METHODS

A retrospective cohort of 558 patients undergoing surgery from February 2018 to March 2021 was included. The patients undergoing surgery before March 2019 served as the historical control group, while the screening group consisted of patients undergoing surgery from March 1, 2019. Troponin I was to be measured 6-12 h postoperatively and in the morning of the succeeding 4 days. Patients with myocardial injury were assessed, and treatment was individualised after multiple disciplinary consultations. The primary outcome was the unadjusted 30-day mortality rates. Inverse probability treatment weighting was used to adjust for selection bias.

RESULTS

We included 558 patients: 382 in the screening group and 176 in the historical control group. In the screening group, 15 patients (3.9%) died before the first blood sampling, and in 31 patients (8.1%), troponin screening was omitted, leaving only 336 patients screened. Myocardial injury was diagnosed in 81 patients (24.1%) of the 336 patients. Of these, 59 (72.8%) had a cardiac consultation. No interventions or alterations in relation to myocardial injury were done in 67 patients (82.7%). The 30-day mortality was 13.8% (95% CI 8.7%-18.9%) in the control group and 11.1% (95% CI 8.0%-14.3%) in the screening group. The absolute risk difference was -2.7% (95% CI -8.7%-3.3%; p = .38), which was unchanged after adjustment. The difference remained unchanged after 90 days and 1 year.

CONCLUSION

The implementation of postoperative troponin screening was not associated with reduced mortality after AHA surgery. Research on the prevention and treatment of MINS is warranted before the implementation of standard troponin screening.

Association between troponin I levels and mortality among patients undergoing acute high-risk abdominal surgery-A cohort study

BACKGROUND

Myocardial injury after noncardiac surgery (MINS) is associated with 30-day mortality in heterogeneous surgical populations but is barely described after acute high-risk abdominal surgery. The impact of dynamic changes has not previously been investigated. The objectives were to determine the incidence of MINS in this population, the association between mortality and MINS, and whether plasma troponin I (TnI) dynamics have any impact on mortality.

METHODS

A prospective cohort study of 341 patients undergoing acute high-risk gastrointestinal surgery was conducted. Plasma TnI was measured at the first four postoperative days. MINS was defined as any increased TnI level >59 ng/L. TnI dynamic required either two succeeding measurements of TnI >59 ng/L with a >20% increase/fall or one measurement of TnI >59 ng/L with a succeeding measurement of TnI <59 ng/L with a >50% decrease. Adjusted mortality rates were calculated using inverse probability of treatment weighting and competing risk analyses.

RESULTS

The incidence of MINS was 23.8% and dynamic TnI changes occurred in 15.6% of the patients. The unadjusted 30-day and 1-year mortality were 19.8% and 35.9% in patients with MINS, compared with 2.7% and 11.6%, respectively, in patients without MINS (p < 0.001). After adjusting, the differences remained significant. There was no difference in mortality between patients with or without dynamic changes in TnI level.

CONCLUSION

MINS occurred frequently and was associated with increased mortality. TnI monitoring might help identify patients with increased risk of mortality and improve care. Research on preventive measures and treatments is warranted.

TRIAL REGISTRATION NUMBER AND AGENCY

ClinicalTrials.gov Identifier: NCT05933837, retrospective registered.

ESAIC focused guideline for the use of cardiac biomarkers in perioperative risk evaluation

BACKGROUND

In recent years, there has been increasing focus on the use of cardiac biomarkers in patients undergoing noncardiac surgery.

AIMS

The aim of this focused guideline was to provide updated guidance regarding the pre-, post- and combined pre-and postoperative use of cardiac troponin and B-type natriuretic peptides in adult patients undergoing noncardiac surgery.

METHODS

The guidelines were prepared using Grading of Recommendations Assessment Development and Evaluation (GRADE) methodology. This included the definition of critical outcomes, a systematic literature search, appraisal of certainty of evidence, evaluation of biomarker measurement in terms of the balance of desirable and undesirable effects including clinical outcomes, resource use, health inequality, stakeholder acceptance, and implementation. The panel differentiated between three different scopes of applications: cardiac biomarkers as prognostic factors, as tools for risk prediction, and for biomarker-enhanced management strategies.

RESULTS

In a modified Delphi process, the task force defined 12 critical outcomes. The systematic literature search resulted in over 25,000 hits, of which 115 full-text articles formed the body of evidence for recommendations. The evidence appraisal indicated heterogeneity in the certainty of evidence across critical outcomes. Further, there was relevant gradient in the certainty of evidence across the three scopes of application. Recommendations were issued and if this was not possible due to limited evidence, clinical practice statements were produced.

CONCLUSION

The ESAIC focused guidelines provide guidance on the perioperative use of cardiac troponin and B-type natriuretic peptides in patients undergoing noncardiac surgery, for three different scopes of application.

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).

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.

Association between cardiologist evaluation and mortality in myocardial injury after non-cardiac surgery

OBJECTIVE

Myocardial injury after non-cardiac surgery (MINS) is strongly associated with mortality, but few studies assessed treatment strategies. This study aimed to identify whether evaluation by cardiologists could reduce mortality in MINS patients.

METHODS

From a single-centre retrospective cohort, we enrolled a total of 5633 adult patients diagnosed with MINS between January 2010 and June 2019. The patients were divided into two groups based on evaluation by cardiologist, which was defined as a cardiology consultation or transfer to the cardiology department. For the outcome, 30-day mortality was compared in crude and propensity-score matched populations.

RESULTS

Of a total of 5633 patients, 2120 (37.6%) were evaluated by cardiologists and 3513 (62.4%) were not. Mortality during the first 30 days after surgery was significantly lower in MINS patients who were evaluated by cardiologists compared with those who were not (5.8% vs 8.3%; HR, 0.64; 95% CI 0.51 to 0.80; p<0.001 for all-cause mortality and 1.6% vs 2.0; HR 0.62; 95% CI 0.40 to 0.96; p=0.03 for cardiovascular mortality). The propensity score matched analysis showed similar results (5.6% vs 8.6%; HR 0.64; 95% CI 0.50 to 0.81; p<0.001 for all-cause mortality and 1.3% vs 2.2%; HR 0.58; 95% CI 0.35 to 0.95; p=0.03 for cardiovascular mortality).

CONCLUSIONS

Cardiologist evaluation was associated with lower mortality in patients diagnosed with MINS. Further studies are needed to identify effective treatment strategies for MINS.

TRIAL REGISTRATION NUMBER

KCT0004244.

Incidence, mortality, and complications of acute myocardial infarction with and without percutaneous coronary intervention in hip fracture patients

INTRODUCTION

Acute myocardial infarction (AMI) is a common cause of death following hip fracture surgery. This study aimed to determine the incidence and timing of perioperative AMI treated with percutaneous coronary intervention (PCI) in hip fracture patients, and to compare in-hospital mortality and complications between hip fracture patients who did not have an AMI, those who sustained a perioperative AMI and did not undergo PCI, and those who sustained an AMI and underwent PCI.

METHODS

The National Inpatient Sample (NIS) was queried from 2010 through the third quarter of 2015 to identify all patients undergoing hip fracture surgery. Patients were stratified into three cohorts: perioperative AMI but no PCI (no PCI cohort), perioperative AMI with PCI (PCI cohort), and no perioperative AMI or PCI (no AMI cohort). Patient demographics, comorbidities, in-hospital mortality, and complications were compared between cohorts. Multivariable logistic regression adjusting for age, sex, procedure, and Elixhauser score was used to assess the relative odds of in-hospital mortality for each cohort.

RESULTS

A total of 1,535,917 hip fracture cases were identified, with 1.9% in the no PCI cohort, 0.01% in the PCI cohort, and 98.0% in the no AMI cohort. In-hospital mortality was lower in the PCI cohort than in the no PCI cohort (8.8% vs. 14%), and was greater for both than in the no AMI cohort (1.6%, p < 0.001 for all). Both the no PCI cohort (OR, 6.1; 95% CI, 5.6-6.6) and PCI cohort (OR, 4.1; 95% CI, 2.8-6.0) had increased adjusted odds of in-hospital mortality compared to the no AMI cohort. The PCI cohort had a higher rate of bleeding complications than both other cohorts, and the no PCI cohort had a higher rate of transfusion than both other cohorts.

CONCLUSIONS

Perioperative AMI both with and without PCI independently increases the risk of mortality in hip fracture patients, with the highest risk of mortality in those with AMI without PCI. Providers should understand the increased morbidity and mortality associated with AMI in hip fracture patients, as well as the risks and benefits of perioperative PCI, in order to better counsel and manage these patients.

LEVEL OF EVIDENCE

III.

Evaluation of spin in the abstracts of orthopedic trauma literature: A cross-sectional review

OBJECTIVES

A cross-sectional analysis of orthopedic trauma randomized controlled trial (RCT) abstracts to assess the frequency and manifestations of spin, the misrepresentation or distortion of research findings, in orthopedic trauma clinical trials.

METHODS

The top 5 orthopedic trauma journals were searched from January 1, 2012, to December 31, 2017. RCTs with nonsignificant endpoints (p > .05) were analyzed for spin in the abstract. The primary endpoint of our investigation was the frequency and type of spin. The secondary endpoint was to assess whether funding source was associated with the presence of spin. Due to the low reporting of funding sources no statistics were able to be computed for this outcome.

RESULTS

Our PubMed search yielded 517 articles. Primary screening excluded 303 articles, and full text evaluation excluded an additional 161. Overall, 53 articles were included. Spin was identified in 35 of the 53 (66.0%) abstracts analyzed. Evidence of spin was found in 21 (39.6%) abstract results sections and 22 (41.5%) abstract conclusion sections. Of the 21 RCTs reporting a clinical trial registry, 3 (14.3%) had evidence of selective reporting bias.

CONCLUSIONS

Orthopedic trauma RCTs from highly ranked journals with nonsignificant endpoints published from 2012 to 2017 frequently have spin in their abstracts. Abstracts with evidence of spin may influence a reader's perception of new drugs or procedures. In orthopedic trauma, the implications of spin may affect the treatment of patients with orthopedic trauma, so efforts to mitigate spin in RCT abstracts must be prioritized.

The prognostic implication of perioperative cardiac enzyme elevation in patients with fractured neck of femur: A systematic review and meta-analysis

BACKGROUND

Neck of Femur (NOF) fractures are a common injury in comorbid elderly patients which are associated with increased rates of morbidity and mortality following fracture. Because of their injury, patients can experience reductions in quality of life and independent living leading to transfer to nursing home or dependent levels of care. Numerous factors are associated with either complications or reductions in survival following fractured NOF. From the VISION cohort there is evidence that troponin elevation in the post-operative period following a diverse range of non-cardiac surgical procedures may lead to an increased risk of mortality in the absence of classical ischaemic or cardiac symptoms. The aim of this systematic review and meta-analysis is to validate the utility of perioperative troponin elevation as a prognostic indicator for mortality and cardiac morbidity in those with fractured NOF.

METHODS

The PRISMA guidelines for the conduct of meta-analyses were followed. An electronic search was conducted of the EMBASE, MEDLINE (Ovid) and Biosis databases. Studies were included for analysis if they stratified outcomes by perioperative troponin elevation in surgically managed fractured NOF and reported sufficient data on troponin elevation and mortality following surgery. Primary and secondary outcomes assessed were all-cause post-operative mortality and a composite measure of cardiac complications (myocardial infarction, cardiac failure and arrhythmia) respectively.

RESULTS

Eleven studies met inclusion criteria giving a total of 1363 patients. Overall, 497 patients (36.5%) experienced an elevation in troponin levels following surgery. Perioperative troponin elevation was significantly associated with all-cause mortality (OR 2.6; 95% CI 1.5 - 4.6; p <0.001) and cardiac complications (OR 7.4; 95% CI 3.5 - 15.8; p <0.001). Patient factors significantly associated with troponin elevation included pre-existing coronary artery disease, cardiac failure, hypertension, previous stroke and previous myocardial infarction.

CONCLUSION

Perioperative troponin elevation is significantly associated with increased mortality and post-operative cardiac complications following fractured NOF and may be a useful prognostic indicator in these patients. Future research should further stratify patients by the magnitude of troponin elevation and further refine the risk factors.

Causes and prevention of postoperative myocardial injury

Over the past few years non-cardiac surgery has been recognised as a serious circulatory stress test which may trigger cardiovascular events such as myocardial infarction, in particular in patients at high risk. Detection of these postoperative cardiovascular events is difficult as clinical symptoms often go unnoticed. To improve detection, guidelines advise to perform routine postoperative assessment of cardiac troponin. Troponin elevation - or postoperative myocardial injury - can be caused by myocardial infarction. However, also non-coronary causes, such as cardiac arrhythmias, sepsis and pulmonary embolism, may play a role in a considerable number of patients with postoperative myocardial injury. It is crucial to acquire more knowledge about the underlying mechanisms of postoperative myocardial injury because effective prevention and treatment options are lacking. Preoperative administration of beta-blockers, aspirin, statins, clonidine, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers, and preoperative revascularisation have all been investigated as preventive options. Of these, only statins should be considered as the initiation or reload of statins may reduce the risk of postoperative myocardial injury. There is also not enough evidence for intraoperative measures such blood pressure optimisation or intensified medical therapy once patients have developed postoperative myocardial injury. Given the impact, better preoperative identification of patients at risk of postoperative myocardial injury, for example using preoperatively measured biomarkers, would be helpful to improve cardiac optimisation.

Myocardial injury after non-cardiac surgery: a perioperative affair?

Myocardial injury after non-cardiac surgery (MINS) is a rather new nosological entity and an unfortunately common perioperative complication. The diagnostic criteria for MINS, also indicated as isolated myocardial injury (IMI), are an elevated postoperative high sensitivity troponin T (hsTnT level ranging between 20 and 65 ng/L with an absolute change of at least 5 ng/L or hsTnT level >65 ng/L), in absence of symptoms and/or EKG findings suggestive of ischemia and without a non-ischemic etiology causing troponin elevation. MINS does not fulfill the universal definition of myocardial infarction even if it is related to ischemic causes and it is independently associated with 30-day postoperative mortality and complications. Nevertheless, mortality at 30 days in MINS patients has been calculated up to 10% and it increases exponentially as a function of peak postoperative troponin concentration. Physician and researchers should discriminate MINS from perioperative myocardial infarction and from not ischemic troponin increases. In the postoperative period, the possibility of missing the diagnosis of an acute coronary syndrome for the paucity of clinical symptoms or because physician failed to evaluate a postoperative EKG recording should always be considered. Physiopathology of MINS is not yet well defined: current hypotheses are surrogated from perioperative myocardial infarction studies. Up to now there are not specific treatments for MINS, even if antithrombotic therapy is under evaluation. Treatment decisions should be tailored to the individual case; potential benefits of troponin screening include a cardiology consultation and consequently, improved patients' information to promote lifestyle changes and enhanced therapy.

One-Year Mortality, Causes of Death, and Cardiac Interventions in Patients with Postoperative Myocardial Injury

BACKGROUND

To evaluate the role of routine troponin surveillance in patients undergoing major noncardiac surgery, unblinded screening with cardiac consultation per protocol was implemented at a tertiary care center. In this study, we evaluated 1-year mortality, causes of death, and consequences of cardiac consultation of this protocol.

METHODS

This observational cohort included 3224 patients ≥60 years old undergoing major noncardiac surgery. Troponin I was measured routinely on the first 3 postoperative days. Myocardial injury was defined as troponin I >0.06 μg/L. Regression analysis was used to determine the association between myocardial injury and 1-year mortality. The causes of death, the diagnoses of the cardiologists, and interventions were determined for different levels of troponin elevation.

RESULTS

Postoperative myocardial injury was detected in 715 patients (22%) and was associated with 1-year all-cause mortality (relative risk [RR] 1.4, P = 0.004; RR 1.6, P < 0.001; and RR 2.2, P < 0.001 for minor, moderate, and major troponin elevation, respectively). Cardiac death within 1 year occurred in 3%, 5%, and 11% of patients, respectively, in comparison with 3% of the patients without myocardial injury (P = 0.059). A cardiac consultation was obtained in 290 of the 715 patients (41%). In 119 (41%) of these patients, the myocardial injury was considered to be attributable to a predisposing cardiac condition, and in 111 patients (38%), an intervention was initiated.

CONCLUSIONS

Postoperative myocardial injury was associated with an increased risk of 1-year all-cause but not cardiac mortality. A cardiac consultation with intervention was performed in less than half of these patients. The small number of interventions may be explained by a low suspicion of a cardiac etiology in most patients and lack of consensus for standardized treatment in these patients.

Cardiac Biomarkers Predict 1-Year Mortality in Elderly Patients Undergoing Hip Fracture Surgery

This prospective study included 152 elderly patients (mean age, 80 years; range, 72-88 years) with a hip fracture treated surgically. Comorbidities were evaluated, and B-type natriuretic peptide was measured at baseline and at postoperative days 4 and 5 in addition to troponin I. Major cardiac events were recorded, and 1-year mortality was assessed. Comorbidity models with the important multivariate predictors of 1-year mortality were analyzed. Overall, 9 patients (6%) experienced major cardiac events postoperatively during their hospitalization. Three patients (2%) died postoperatively, at days 5, 7, and 10, from autopsy-confirmed myocardial infarction. Three patients (2%) experienced a nonfatal myocardial infarction, and 3 patients (2%) experienced acute heart failure. At 1-year follow-up, 37 patients (24%) had died. Age older than 80 years (P=.000), renal failure (P=.016), cardiovascular disease (P=.003), respiratory disease (P=.010), Parkinson disease (P=.024), and dementia (P=.000) were univariate predictors of 1-year mortality. However, in the multivariate model, only age older than 80 years (P=.000) and dementia (P=.024) were important predictors of 1-year mortality. In all comorbidity models, age older than 80 years and dementia were important predictors of 1-year mortality. Postoperative increase in B-type natriuretic peptide was the most important predictor of 1-year mortality. Receiver operating characteristic curve analysis showed a threshold of 90 ng/mL of preoperative B-type natriuretic peptide (area under the curve=0.773, 95% confidence interval, 0.691-0.855, P<.001) had 82% sensitivity and 62% specificity to predict 1-year mortality. Similarly, a threshold of 190 ng/mL of postoperative B-type natriuretic peptide (area under the curve=0.753, 95% confidence interval, 0.662-0.844, P<.001) had 70% sensitivity and 77% specificity to predict the study endpoint. [Orthopedics. 2017; 40(3):e417-e424.].

Sleep apnea in total joint arthroplasty patients and the role for cardiac biomarkers for risk stratification: an exploration of feasibility

Obstructive sleep apnea (OSA) is highly prevalent in patients undergoing total joint arthroplasty (TJA) and is a major risk factor for postoperative cardiovascular complications and death. Recognizing this, the American Society of Anesthesiologists urges clinicians to implement special considerations in the perioperative care of OSA patients. However, as the volume of patients presenting for TJA increases, resources to implement these recommendations are limited. This necessitates mechanisms to efficiently risk stratify patients having OSA who may be susceptible to post-TJA cardiovascular complications. We explore the role of perioperative measurement of cardiac troponins (cTns) and brain natriuretic peptides (BNPs) in helping determine which OSA patients are at increased risk for post-TJA cardiovascular-related morbidity.

Relation of perioperative elevation of troponin to long-term mortality after orthopedic surgery

Myocardial necrosis in the perioperative period of noncardiac surgery is associated with short-term mortality, but long-term outcomes have not been characterized. We investigated the association between perioperative troponin elevation and long-term mortality in a retrospective study of consecutive subjects who underwent hip, knee, and spine surgery. Perioperative myocardial necrosis and International Classification of Disease, Ninth Revision-coded myocardial infarction (MI) were recorded. Long-term survival was assessed using the Social Security Death Index database. Logistic regression models were used to identify independent predictors of long-term mortality. A total of 3,050 subjects underwent surgery. Mean age was 60.8 years, and 59% were women. Postoperative troponin was measured in 1,055 subjects (34.6%). Myocardial necrosis occurred in 179 cases (5.9%), and MI was coded in 20 (0.7%). Over 9,015 patient-years of follow-up, 111 deaths (3.6%) occurred. Long-term mortality was 16.8% in subjects with myocardial necrosis and 5.8% with a troponin in the normal range. Perioperative troponin elevation (hazard ratio 2.33, 95% confidence interval 1.33 to 4.10) and coded postoperative MI (adjusted hazard ratio 3.51, 95% confidence interval 1.44 to 8.53) were significantly associated with long-term mortality after multivariable adjustment. After excluding patients with coronary artery disease and renal dysfunction, myocardial necrosis remained associated with long-term mortality. In conclusion, postoperative myocardial necrosis is common after orthopedic surgery. Myocardial necrosis is independently associated with long-term mortality at 3 years and may be used to identify patients at higher risk for events who may benefit from aggressive management of cardiovascular risk factors.

Use of ivabradine and atorvastatin in emergent orthopedic lower limb surgery and computed tomography coronary plaque imaging and novel biomarkers of cardiovascular stress and lipid metabolism for the study and prevention of perioperative myocardial infarction: study protocol for a randomized controlled trial

Background

The incidence of perioperative myocardial infarction (PMI) globally is known to be around 2 to 3% and can prolong hospitalization, increased morbidity and mortality. Little is known about the pathophysiology and risk factors for PMI. We investigate the presence of elevated novel cardiac markers and preoperative coronary artery plaque through contemporary laboratory techniques to determine the correlation with PMI, as well as studying ivabradine and atorvastatin as protective pharmacotherapies against PMI in the context of orthopedic surgery.

Methods/Design

We aim to enroll 200 patients aged above 60 years who suffer from neck of femur fracture requiring surgery. Patients will be randomized to four arms (no study drugs, atorvastatin only, ivabradine only and ivabradine and atorvastatin). Our primary outcome is incidence of PMI. All patients will receive an electrocardiogram, cardiac echocardiography, measurement of novel cardiac biomarkers and computed tomography (CT) coronary angiography. A telephone interview post discharge will be conducted at 30 days, 60 days and 1 year.

Discussion

We postulate that ivabradine and atorvastatin will reduce the rate and magnitude of PMI following surgery by reducing heart rate and attenuating catecholamine-induced tachycardia postoperatively. Secondly, we postulate that postoperative reduction in heart rate and catecholamine-induced tachycardia with ivabradine will correlate with a reduction in cardiovascular novel biomarkers which will reduce atrial stretch and postoperative incidence of arrhythmia. We aim to demonstrate that treatment with ivabradine and atorvastatin will cause a reduction in the incidence and magnitude of PMI, the benefit of which is derived primarily in patients with greater atherosclerotic burden as measured by higher CT coronary calcium scores.

Trial registration

This study protocol has been listed in the Australia New Zealand Clinical Trial Registry (registration number: ACTRN12612000340831) on 23 March 2012.

Myocardial Injury After Noncardiac Surgery and its Association With Short-Term Mortality

Background—

To identify patients at risk for postoperative myocardial injury and death, measuring cardiac troponin routinely after noncardiac surgery has been suggested. Such monitoring was implemented in our hospital. The aim of this study was to determine the predictive value of postoperative myocardial injury, as measured by troponin elevation, on 30-day mortality after noncardiac surgery.

Methods and Results—

This observational, single-center cohort study included 2232 consecutive intermediate- to high-risk noncardiac surgery patients aged ≥60 years who underwent surgery in 2011. Troponin was measured on the first 3 postoperative days. Log binomial regression analysis was used to estimate the association between postoperative myocardial injury (troponin I level >0.06 μg/L) and all-cause 30-day mortality. Myocardial injury was found in 315 of 1627 patients in whom troponin I was measured (19%). All-cause death occurred in 56 patients (3%). The relative risk of a minor increase in troponin (0.07–0.59 μg/L) was 2.4 (95% confidence interval, 1.3–4.2; P <0.01), and the relative risk of a 10- to 100-fold increase in troponin (≥0.60 μg/L) was 4.2 (95% confidence interval, 2.1–8.6; P <0.01). A myocardial infarction according to the universal definition was diagnosed in 10 patients (0.6%), of whom 1 (0.06%) had ST-segment elevation myocardial infarction.

Conclusions—

Postoperative myocardial injury is an independent predictor of 30-day mortality after noncardiac surgery. Implementation of postoperative troponin monitoring as standard of care is feasible and may be helpful in improving the prognosis of patients undergoing noncardiac surgery.