Perioperative Myocardial Ischemia Research Articles

Impact of coronary computed tomography angiography (CCTA) in risk assessment of peri-operative myocardial ischemia for patients undergoing vascular surgery

It is recommended to perform a functional test (FT) or a coronary angiography (CA) in patients elected for vascular surgery, to predict peri-operative risk of myocardial ischemia. CCTA has proved its benefit for coronary artery disease rule out in case of chest pain and stable angina. However, its effectiveness has never been evaluated in patients’ candidates for vascular surgery. Compare CCTA, FT and CA for risk assessment of peri-operative myocardial ischemia of patients undergoing vascular surgery. Patients referred for vascular surgery between November 2017 and January 2019 were prospectively included. Three groups were defined according to the pre-operative test performed: FT, CCTA or CA. A CCTA or a CA were considered positive when at least one coronary lesion > 50% was detected. A systematic postoperative troponin assay was performed and considered significant if > 5 N. The primary end point was the comparison of troponin value following vascular surgery according to the pre-operative test performed. The secondary end point was the evaluation of the accuracy of CCTA and FT to detect significant coronary lesions in comparison with CA. A total of 172 patients were included: 60 patients in the FT group of which 38 were negative, 59 patients in the CCTA group of which 37 were negative and 53 patients in the CA group of which 18 were negative. Rates of post-operative troponin elevation was significantly lower in the negative CCTA group than in the negative FT group (1(3%) vs. 10 (26%), P = 0,007) but similar to that in the negative CA group (vs. 1(6%)). A total of 4 (22%) patients with positive CCTA had a negative CA and 8 (24%) of positive FT had a negative CA. CCTA could be a non-invasive alternative to pre-operative CA in patient referred for vascular surgery with better diagnostic performance than FT for rule out coronary lesion at risk of ischemia. However, CCTA should be reserved to selected patients.

Effect of dexmedetomidine on attenuation of hemodynamic response to intubation, skin incision, and sternotomy in coronary artery bypass graft patients: A double-blind randomized control trial.

Background and Aims:Coronary artery bypass grafting (CABG) surgery involves various noxious stimuli resulting in stress response, which in turn increases the risk of perioperative myocardial ischemia. The present study was conducted to evaluate the effect of dexmedetomidine on the attenuation of hemodynamic response to intubation, skin incision, and sternotomy in CABG surgery.Material and Methods:Sixty patients were randomized into two groups of 30 each. Group D patients received dexmedetomidine 1 μg/kg as loading dose over 10 min, followed by continuous infusion of 0.5 μg/kg/h. In group P, normal saline was infused as loading and maintenance dose at similar rate. Hemodynamic parameters, total induction dose of thiopentone, and adverse effects were recorded. Statistical analysis was performed using SPSS version 20.0. Chi-square test and ANNOVA test were used and P < 0.05 was considered significant.Results:The percentage increase in heart rate was significantly lesser in group D than group P after intubation (7.04% v/s 15.08%), skin incision (5.91% v/s 10.11%), and sternotomy (5.33% v/s 11.65%). Similarly increase in systolic, diastolic, and mean blood pressure were significantly lesser in group D than group P after intubation, skin incision, and sternotomy. There was a significant reduction of mean total of thiopentone in group D in comparison to group P. (1.16 mg/kg v/s 2.44 mg/kg) (P<0.001).Conclusion:Dexmedetomidine resulted in significant attenuation of hemodynamic response to intubation, skin incision, and sternotomy in CABG surgery without significant adverse effects. It also significantly reduced the dose of thiopentone required for induction.

Postoperative Cardiac Ischemic Complications in Lung Cancer Patients

Background. Perioperative myocardial ischemia often complicates extracardiac surgery. The problems of its prediction, diagnostics, treatment and prevention are not solved. Frequency, structure and clinical features of cardiac ischemic complications of surgical treatment of lung cancer are not well understood.The aim of the study was to investigate the frequency of postoperative myocardial infarction and myocardial ischemia in the surgical treatment of patients with non-small cell lung cancer.Methods. The frequency (%) of myocardial infarction (MI) with and without ST segment elevation of electrocardiogram, acute myocardial ischemia in a complete sample of cancer patients (n = 2051) who underwent treatment for non-small cell lung cancer for the last 10 years was calculated. By comparing the relative indicators and calculating the Odds Ratio (OR), we studied the relationship between the cardiac ischemic events with age, type of surgery, prevalence and localization of the tumour. The clinical manifestations and pathomorphology of postoperative myocardial infarction were analysed.Results. Cardiac ischemic complications of thoracotomy for lung cancer occurred in 2.73 % (95% CI 1.98–3.48) cases. Myocardial infarction with ST segment elevation was recorded in 1.07 % (95% CI 0.58–1.57) patients, MI without ST segment elevation – in 0.54 % (95% CI 0.17–0.9), myocardial ischemia – in 1.12 % (95% CI 0.62–1.63). An increase in the frequency of ischemic events after pneumonectomy was observed compared with lobectomy (OR 6.5, 95% CI 3.5–12.2) and after right-sided pneumonectomy compared with left-sided one (OR 3.2, 95% CI 1.6–6.3), and also the age over 70. Hospital mortality from MI was 39.3 %. According to autopsies of patients who died of МI, coronary atherothrombosis was detected in 2 of 22 cases.Conclusion. In the surgical treatment of non-small cell lung cancer, cardiac ischemic events develop in 2.73 % of patients. The greatest risk is associated with right-sided pneumonectomy.

Rationale and design of perioperative myocardial ischemia: a protocol for troponin monitoring, prognostic thresholds, economic analysis and further insights into pathophysiology for non-cardiac surgery patients

Introduction: Worldwide, near 200 million adults undergo major non cardiac surgery each year, and 10 million of them are estimated to suffer a myocardial injury after non-cardiac surgery (MINS), defined as an elevated high sensitive troponin T (hs-cTnT) in the first 3 days after surgery. Troponin levels need to be monitored in order to diagnose MINS, high sensitive cardiac Troponin T (hs-cTnT) assays being currently the most frequently used. Perioperative hs-cTnT screening could lead to care decisions that can potentially improve clinical outcomes. However, many of the clinical and economic implications of perioperative hs-cTnT monitoring remain unclear, and need to be elucidated. Methods and analysis: Prospective cohort that will include patients with high cardiovascular risk undergoing major non-cardiac surgery, expected to require at least an overnight hospital admission. Three determinations of hs-cTnT in each patient (before surgery, at 48, and 72 hours after surgery) will be obtained. We will determine the incidence and prognosis of MINS, and calculate prognostically relevant thresholds for pre- and post-operative hs-cTnT. We will also conduct a cost-effectiveness analysis of hs-cTnT screening, compared with usual care. Finally, using computed tomography angiography (CTA) and cardiac magnetic resonance imaging (MRI), we aim to elucidate further the pathophysiology of MINS. Ethics and dissemination: Our center had Ethics approval before including patients. Written informed consent is required for all patients before inclusion. The study will evaluate the feasibility and impact of implementing an hs-cTnT monitoring program at a tertiary hospital, as well as its cost-effectiveness, determine pre and postoperative thresholds of hs-cTnT and finally, evaluate potential mechanisms involved in perioperative ischemic events. The dissemination plan includes publishing the results in a policy-influencing journal, conference presentations, engagement of influential medical organizations, and taking published results to real practice.

Management of perioperative myocardial ischaemia after isolated coronary artery bypass graft surgery

ObjectivesUpdated knowledge about perioperative myocardial ischaemia (MI) after coronary artery bypass grafting (CABG) and treatment of acute graft failure is needed. We analysed main factors associated with perioperative MI and...

New advances in perioperative cardioprotection.

With the increasing age of the general population, medical conditions necessitating a surgical intervention will increase. Concomitant with advanced age, the prevalence of type 2 diabetes mellitus will also increase. These patients have a two- to three-fold higher risk of occurrence of cardiovascular events and are at higher risk of perioperative myocardial ischemia. This review will discuss recent advances in the field of perioperative cardioprotection and focus specifically on strategies that have aimed to protect the diabetic and the aged myocardium. This review will not deal with potential putative cardioprotective effects of opioids and anesthetic agents, as this is a very broad area that would necessitate a dedicated overview.

Efficacy and safety of intravenous esmolol for cardiac protection in non-cardiac surgery. A systematic review and meta-analysis

Haemodynamic instability predisposes patients to cardiac complications in non-cardiac surgery. Esmolol, a short-acting cardioselective beta-adrenergic blocker might be efficient in perioperative cardiac protection, but could affect other vital organs, such as the kidneys, and post-discharge survival. We performed a systematic review on the use of esmolol for perioperative cardiac protection. We searched PubMed, Ovid Medline and Cochrane Central Register for Controlled trials. Eligible randomized controlled studies (RCTs) reported a perioperative esmolol intervention with at least one of the primary (major cardiac or renal complications during the first 30 postoperative days) or secondary (postoperative adverse effects and all-cause mortality) outcomes. We included 196 adult patients from three RCTs. Esmolol significantly reduced postoperative myocardial ischaemia, RR =0.43 [95% confidence interval, CI: 0.21–0.88], p = .02. No association with clinically significant bradycardia and hypotension compared to patients receiving control treatment could be confirmed (RR =7.4 [95% CI: 0.29–139.81], p = .18 and RR =2.21 [95% CI: 0.34–14.36], p = .41, respectively). No differences regarding other outcomes were observed. No study reported postoperative renal outcomes. Esmolol seems promising for the prevention of perioperative myocardial ischaemia. However, the association with bradycardia and hypotension remains unclear. Randomized trials investigating the effect of β1-selective blockade on clinically relevant outcomes and non-cardiac vital organs are warranted.Key messagesShort-acting cardioselective esmolol seems efficient in the prevention of perioperative myocardial ischaemia.The possibly increased risk of bradycardia and hypotension with short-acting intravenous beta blockade could not be confirmed or refuted by available data. Future adequately powered trials investigating the effect of β1-selective blockade on clinically relevant outcomes and non-cardiac vital organs are warranted.

Trials and Frontiers in Carotid Endarterectomy and Stenting.

Based on the strength of randomized trials from the 1990s, major societal guidelines recommend carotid endarterectomy (CEA) for severe (≥70%), symptomatic carotid stenosis if an operative stroke/death rate of <6% can be maintained (history and major trials in carotid revascularization are summarized in the online-only Data Supplement).1–4 Though the benefit is less evident, most guidelines also recommend consideration of CEA for 50% to 69% symptomatic stenosis.2–4 There are subtle differences in recommendations regarding carotid artery stenting (CAS) in symptomatic patients. Some guidelines stipulate that CEA should be preferred over CAS in patients with severe (≥70%) symptomatic carotid stenosis,2,5 especially if >70 years old,4 whereas others position CAS as an alternative.1,3 Though the risk of operative stroke/death is higher with CAS, major randomized clinical trials (RCTs) report event rates under the recommended 6% cutoff for both treatment modalities. Regarding asymptomatic disease, CEA is recommended for patients with stenosis ≥60% to 70% in highly selected patients as long as operative stroke/death rates <3% can be maintained.1 A predicted life expectancy of at least 3 to 5 years has also been suggested.2 The 3% threshold has been easily met by CEA cohorts in the CREST (Carotid Revascularization Endarterectomy Versus Stenting Trial; 1.4%)6 and the ACT1 (Asymptomatic Carotid Trial; 1.7%),7 suggesting that an even lower threshold may be appropriate. Controversially, some guidelines have recommended that CAS can be considered in highly selected patients with asymptomatic carotid stenosis ≥60% to 70%,1,4,8 whereas others argue that the evidence remains insufficient.2 The lack of consensus in the management of asymptomatic carotid stenosis is reflective of an ongoing need for high-quality RCT data to guide practice. ### CEA Operative Stroke Risk and High Risk Designation Most clinical trials in carotid revascularization have focused …

Control angiography for perioperative myocardial Ischemia after coronary surgery: meta-analysis

BackgroundPerioperative myocardial ischemia (PMI) in patients undergoing coronary artery bypass grafting (CABG) is associated with poor outcome. The aim of this study was to pool the available data on the outcome after control angiography and repeat revascularization in patients with perioperative myocardial ischemia (PMI) after coronary artery bypass grafting (CABG).MethodsA literature review was performed through PubMed, Scopus, ScienceDirect and Google Scholar to identify studies published since 1990 evaluating the outcome of PMI after CABG.ResultsNine studies included 1104 patients with PMI after CABG and 1056 of them underwent control angiography early after CABG. Pooled early mortality after reoperation for PMI without control angiography was 43.6% (95%CI 29.7-57.6%) and 79.8% of them (95%CI 64.4-95.2%) had an acute graft failure detected at reoperation. Among patients who underwent control angiography for PMI, 31.7% had a negative finding at angiography (95%CI 25.6-37.8%) and 62.1% had an acute graft failure (95%CI 56.6-67.6%). Repeat revascularization was performed after early control angiography in 46.3% of patients (95%CI 39.9-52.6%; 54.2% underwent repeat surgical revascularization; 45.8% underwent percutaneous coronary intervention). Pooled early mortality after control angiography with or without repeat revascularization was 8.9% (95%CI 6.7-11.1%). Three studies reported on early mortality rates which did not differ between repeat surgical revascularization and PCI (11.7% vs. 9.2%, respectively; risk ratio 1.45, 95%CI 0.67-3.11). In these three series, early mortality after conservative treatment was 5.9% (95%CI 3.6-8.2%).ConclusionsControl angiography seems to be a valid life-saving strategy to guide repeat revascularization in hemodynamically stable patients suffering PMI after CABG.

A Comparative Study of Intubating Conditions between PropofolFentanyl-Midazolam and Propofol-Fentanyl-Lignocaine Groups without Neuromuscular Blocking Agents

A Comparative Study of Intubating Conditions between PropofolFentanyl-Midazolam and Propofol-Fentanyl-Lignocaine Groups without Neuromuscular Blocking Agents

Survival results of postoperative coronary angiogram for treatment of perioperative myocardial ischaemia following coronary artery bypass grafting: a single-centre experience.

Although perioperative myocardial ischaemia (PMI) is a well-known complication following coronary artery bypass grafting (CABG), standard strategies for its diagnosis and treatment are so far not defined. In this study, we sought to evaluate the impact on survival of postoperative coronary angiogram for management of patients with PMI after CABG. Overall, 4028 patients underwent isolated CABG in a single-centre institution between January 2006 and September 2013. A total of 168 (4.2%) patients received postoperative coronary angiogram because of diagnosis of PMI. These patients were matched on the basis of gender, age at surgery and date of surgery, with 336 (1:2 ratio) CABG patients without PMI to determine the impact of the PMI management. A total of 476 grafts were examined (263 venous grafts, 196 internal mammary artery grafts and 17 radial artery grafts). Almost three-quarters of the 168 PMI (74.4%) patients underwent postoperative coronary angiogram within 24 h of surgery. Normal postoperative coronary angiogram, graft failure and new native vessels occlusion were observed in 23.2%, 52.4% and 24.4% of patients, respectively. A total of 30 (17.9%) patients underwent surgical revision of grafts, whereas 60 (35.7%) patients were treated with percutaneous coronary intervention. Eighteen (10.7%) PMI patients died during the hospital stay compared with 6 (1.8%) patients in the non-PMI group. Survival rates at 7 years were 62.5% in the PMI group and 81.1% in non-PMI group (P < 0.001). After multivariable adjustment PMI (P < 0.001; hazard ratio 3.17, 95% confidence interval 2.12-4.73) turned out to be an independent predictor of mortality on follow-up. Moreover, further subanalysis revealed that delayed postoperative coronary angiogram (>24 h after surgery) was an independent predictor of poorer mid-term survival (P = 0.008; hazard ratio 3.62, 95% confidence interval 1.41-9.33). PMI after CABG is associated with a significantly poorer survival. A prompt postoperative management must always be considered. Further prospective studies are required to confirm our results.

Influence of dexmedetomidine on cardiac complications in non-cardiac surgery: a meta-analysis of randomized trials.

Background The cardiac protection of dexmedetomidine (Dex) in peri-operative period of patients with non-cardiac surgery is still controversial. Aim of the Review We aimed to evaluate the influence of Dex on cardiac complications in peri-operative period of non-cardiac surgery by using a meta-analysis. Methods PubMed, Embase, the Cochrane library and Springer databases were searched for relevant studies. Patients in the eligible studies were divided into Dex group and placebo group. Relative risk (RR) and the 95% confidence interval (CI) were calculated to evaluate the outcomes including all-cause mortality, myocardial infarction, myocardial ischaemia, hypotension and bradycardia. Subgroup analysis was performed based on the dosage of Dex. Publication bias was assessed by Egger's test. Results Twenty double-blind randomized controlled trials containing 1157 patients were included in this meta-analysis. The pooled results showed no significant difference between Dex group and placebo group in peri-operative myocardial infarction, myocardial ischaemia and all-cause mortality. However, Dex group showed higher risk of hypotension (RR=1.46, 95% CI 1.07, 2.01) and bradycardia (RR=1.98, 95% CI 1.33, 2.95) than that of placebo group. In addition, significant publication bias was found among studies involving hypotension and bradycardia. In subgroup analysis, the risk of bradycardia was significantly higher in 1.0μg/kg Dex group than that in placebo group. Besides, a higher risk of hypotension in 0.5μg/kg Dex group than that in placebo group was found. Conclusions Dex supplement might not reduce the risk of cardiac complications but increases the risk of hypotension and bradycardia in peri-operative period of patients who underwent non-cardiac surgeries.

The application of remote ischemic conditioning in cardiac surgery.

Perioperative myocardial ischemia and infarction are the leading causes of morbidity and mortality following anesthesia and surgery. The discovery of endogenous cardioprotective mechanisms has led to testing of new methods to protect the human heart. These approaches have included ischemic pre-conditioning, per-conditioning, post-conditioning, and remote conditioning of the myocardium. Pre-conditioning and per-conditioning include brief and repetitive periods of sub-lethal ischemia before and during prolonged ischemia, respectively; and post-conditioning is applied at the onset of reperfusion. Remote ischemic conditioning involves transient, repetitive, non-lethal ischemia and reperfusion in one organ or tissue (remote from the heart) that renders myocardium more resistant to lethal ischemia/reperfusion injury. In healthy, young hearts, many conditioning maneuvers can significantly increase the resistance of the heart against ischemia/reperfusion injury. The large multicenter clinical trials with ischemic remote conditioning have not been proven successful in cardiac surgery thus far. The lack of clinical success is due to underlying risk factors that interfere with remote ischemic conditioning and the use of cardioprotective agents that have activated the endogenous cardioprotective mechanisms prior to remote ischemic conditioning. Future preclinical research using remote ischemic conditioning will need to be conducted using comorbid models.

Targeted adhesion of dendrimer nanocarriers to hypoxia-injured primary cardiomyocyte cultures

Objective To prepare nanocarriers capable of targeting hypoxia-injured cardiomyocytes and to investigate its physicochemical characteristics, cytotoxicity and efficiency of targeted binding to injured primary cardiomyocytes. Methods The dendrimer nanocarriers(non-targeting nanocarriers) and angiotensin Ⅱ Type 1(AT1)-modified dendrimer nanocarriers(targeting nanocarriers) were synthesized. The chemical structure, gene compact capacity, particle sizes and zeta potentials of the targeting nanocarriers were determined and the morphology was observed. The primary cardiomyocytes of neonatal SD rats were cultured in 3 different conditions: with non-targeting nanocarriers under hypoxia, with targeting nanocarriers under hypoxia, and with targeting nanocarriers under normal culture condition. The targeted adhesion of the nanocarriers to injured cardiomyocytes and normal cardiomyocytes were observed under a laser scanning confocal microscope and quantified with flow cytometry. The toxicity of nanocarriers to cardiomyocytes was also assessed. Results Non-targeting nanocarriers and targeting nanocarriers were successfully synthesized. When the weight ratio of targeting nanocarriers to gene was 6:1, the gene was completely incorporated, and formed spherical particles with a diameter of (180±55) nm and a zeta potential of +5.4 mV. When the concentrations of nanocarriers were less than 200 mg/L, the cell viability was more than 85% at a series of time points. Compared with hypoxia injury+non-targeted group and normal+targeted group, the targeted adhesion efficiency of myocardial cell membrane was significantly enhanced in hypoxia injury+targeted group. Conclusions AT1-modified dendrimer nanocarrier was successfully prepared, which can effectively bind to the injured cardiomyocytes overexpressing angiotensin Ⅱ type 1 receptors(AT1R) with low cytotoxicity. It may provide a new targeted delivery strategy for gene therapy of perioperative myocardial ischemia. Key words: Dendrimer; Cardiomyocyte; Targeting; Angiotensin Ⅱ type 1; Nanocarrier

Impact on Mid-term Survival of Early Repeated Coronary Angiogram for Perioperative Myocardial Ischemia Following CABG: A Case-Control Study

Impact on Mid-term Survival of Early Repeated Coronary Angiogram for Perioperative Myocardial Ischemia Following CABG: A Case-Control Study

Bleeding risk associated with eptifibatide (Integrilin) bridging in thoracic surgery patients.

Antiplatelet use for treatment of coronary artery disease (CAD) is common amongst thoracic surgery patients. Perioperative management of antiplatelet agents requires balancing the opposing risks of myocardial ischemia and excessive bleeding. Perioperative bridging with short-acting intravenous antiplatelet agents has shown promise in preventing myocardial ischemia, but may increase bleeding. We sought to determine whether perioperative bridging with eptifibatide increased bleeding associated with thoracic surgery. After Institutional Review Board approval, we identified thoracic surgery patients receiving eptifibatide at our institution (n = 30). These patients were matched 1:2 with control patients with CAD who did not receive eptifibatide from an institutional database of general thoracic surgery patients. The primary endpoint for our study was the number of units of blood transfused perioperatively. There were no differences in our primary endpoint, number of units of blood products transfused. There were also no differences noted between groups in intraoperative blood loss, chest tube duration, or postoperative length of stay (LOS). While there were no difference noted in overall complications, including our outcome of perioperative MI or death, composite cardiovascular events were more common in the eptifibatide group. In our retrospective exploratory analysis, eptifibatide bridging in patients with high-risk or recent PCI was not associated with an increased need for perioperative transfusion, bleeding, or increased LOS. In addition, we found a similar rate of perioperative mortality or myocardial infarction in both groups, though the ability of eptifibatide to protect against perioperative myocardial ischemia is unclear given different baseline CAD characteristics.

Beta-Adrenergic Receptor Blockers in Hypertension: Alive and Well

Beta-adrenergic receptor blockers (β-blockers) are an appropriate treatment for patients having systemic hypertension (HTN) who have concomitant ischemic heart disease (IHD), heart failure, obstructive cardiomyopathy, aortic dissection or certain cardiac arrhythmias. β-Blockers can be used in combination with other antiHTN drugs to achieve maximal blood pressure control. Labetalol can be used in HTN emergencies and urgencies. β-Blockers may be useful in HTN patients having a hyperkinetic circulation (palpitations, tachycardia, HTN, and anxiety), migraine headache, and essential tremor. β-Blockers are highly heterogeneous with respect to various pharmacologic properties: degree of intrinsic sympathomimetic activity, membrane stabilizing activity, β1 selectivity, α1-adrenergic blocking effects, tissue solubility, routes of systemic elimination, potencies and duration of action, and specific properties may be important in the selection of a drug for clinical use. β-Blocker usage to reduce perioperative myocardial ischemia and cardiovascular (CV) complications may not benefit as many patients as was once hoped, and may actually cause harm in some individuals. Currently the best evidence supports perioperative β-blocker use in two patient groups: patients undergoing vascular surgery with known IHD or multiple risk factors for it, and for those patients already receiving β-blockers for known CV conditions.

Beta-blockers in vascular surgery patients: is the debate still going on?

Patients undergoing vascular surgery are under increased risk for perioperative myocardial ischemia and cardiovascular complications, and optimal medical treatment is therefore imperative for these patients. Beta-blockade has been introduced as a cornerstone of optimal management, and standardized preoperative initiation has been recommended in the past. However, recent pooled data have questioned prior recommendations and have led to revision of international guidelines. This review aims to highlight the debate on perioperative beta-blockade for vascular surgery patients in order to produce useful conclusions for everyday clinical practice.

Surgical Apgar score is associated with myocardial injury after noncardiac surgery

Study ObjectiveTo assess the impact of intraoperative hemodynamics in the development of perioperative myocardial infarction (MI) and myocardial ischemia after noncardiac surgery. DesignSingle-center retrospective cohort study of surgical patients from 2007 to 2012. SettingPostanesthesia care unit, intensive care unit, and medical-surgical ward at an academic tertiary medical center. PatientsA total of 46,799 adult noncardiac, nonthoracic surgery patients, for which 2290 peak cardiac troponin (cTn) levels were available. MeasurementsThe 10-point Surgical Apgar Score (SAS) was calculated from intraoperative heart rate, blood pressure, and blood loss. Peak troponin (cTn) levels, hospital length of stay, 7- and 30-day postoperative mortality, patient demographics, and prior medical conditions were gathered. Troponin leak was defined as cTn-I 0.6 to 1.5 ng/mL or cTn-T 0.1 to 0.3 ng/mL; perioperative MI criteria were cTn-I greater than 1.5 ng/mL or cTn-T greater than 0.30 ng/mL. Main resultsOf 46,799 noncardiac surgical cases, 209 (0.4%) and 192 (0.4%) suffered cTn leak and MI, respectively. Low SAS (0-4) was associated with increased risk of cTn leak and perioperative MI (univariate odds ratio, 2.76 and 2.06; 95% confidence interval, 2.20-3.45 and 1.57-2.70, respectively). In multivariable analysis, Surgical Apgar Score, age 65 years or older, American Society of Anesthesiologists physical status greater than or equal to III, emergency surgery, history of MI or hypertension, prolonged intraoperative tachycardia (heart rate >100 beats/min for >59 minutes), and prolonged hypotension (mean arterial pressure <40 mm Hg for >2 minutes) were independently associated with cTn leak and perioperative MI. ConclusionsLow SAS scores (0-4) may be associated with cTn elevation after noncardiac surgery. SAS-based risk stratification may guide perioperative cTn surveillance in lieu of routine postoperative screening.

Myocardial injury after noncardiac surgery: an underappreciated problem and current challenges.

To review myocardial injury after noncardiac surgery (MINS), focusing on recent studies, including data on high-sensitivity troponin, which is likely to alter our understanding of MINS. MINS is greatly underappreciated by clinicians, possibly because of its silent presentation. However, MINS is both common and clinically important. In total, 8% of at-risk patients will suffer a MINS, an event that is associated with death within 30 days with an odds ratio of 3.87 (95% CI 2.96-5.08). Most patients suffering MINS do not fulfill the criteria for perioperative myocardial infarction as they are asymptomatic. Consequently, postoperative troponin measurement is imperative for MINS detection. Evidence from randomized trials on how to prevent or how to treat MINS is still lacking. Currently, we are limited to appreciating the vast extent of the MINS problem and applying recommendations based on observational data or derived from the nonoperative setting. Routine troponin measurements after noncardiac surgery and the increasing use of high-sensitivity troponins have revealed the larger underwater iceberg of perioperative myocardial injury and ischemia. Clinicians should be sensitized for this important complication and search for it using a perioperative troponin screening.