Trends and In-Hospital Mortality for Perioperative Myocardial Infarction After the Introduction of a Diagnostic Code for Type 2 Myocardial Infarction in the United States Between 2016 and 2018.

BACKGROUND: The frequency of perioperative myocardial infarction has been declining; however, previous studies have only described type 1 myocardial infarctions. Here, we evaluate the overall frequency of myocardial infarction with the addition of an International Classification of Diseases 10th revision (ICD-10-CM) code for type 2 myocardial infarction and the independent association with in-hospital mortality. METHODS: A longitudinal cohort study spanning the introduction of the ICD-10-CM diagnostic code for type 2 myocardial infarction using the National Inpatient Sample (NIS) from 2016 to 2018. Hospital discharges that included a primary surgical procedure code for intrathoracic, intraabdominal, or suprainguinal vascular surgery were included. Type 1 and type 2 myocardial infarctions were identified using ICD-10-CM codes. We used segmented logistic regression to estimate change in frequency of myocardial infarctions and multivariable logistic regression to determine the association with in-hospital mortality. RESULTS: A total of 360,264 unweighted discharges were included, representing 1,801,239 weighted discharges, with median age 59 and 56% female. The overall incidence of myocardial infarction was 0.76% (13,605/1,801,239). Before the introduction of type 2 myocardial infarction code, there was a small baseline decrease in the monthly frequency of perioperative myocardial infarctions (odds ratio [OR], 0.992; 95% confidence interval [CI], 0.984-1.000; P = .042), but no change in the trend after the introduction of the diagnostic code (OR, 0.998; 95% CI, 0.991-1.005; P = .50). In 2018, where there was an entire year where type 2 myocardial infarction was officially a diagnosis, the distribution of myocardial infarction type 1 was 8.8% (405/4580) ST elevation myocardial infarction (STEMI), 45.6% (2090/4580) non-ST elevation myocardial infarction (NSTEMI), and 45.5% (2085/4580) type 2 myocardial infarction. STEMI and NSTEMI were associated with increased in-hospital mortality (OR, 8.96; 95% CI, 6.20-12.96; P < .001 and OR, 1.59; 95% CI, 1.34-1.89; P < .001). A diagnosis of type 2 myocardial infarction was not associated with increased odds of in-hospital mortality (OR, 1.11; 95% CI, 0.81-1.53; P = .50) when accounting for surgical procedure, medical comorbidities, patient demographics, and hospital characteristics. CONCLUSIONS: The frequency of perioperative myocardial infarctions did not increase after the introduction of a new diagnostic code for type 2 myocardial infarctions. A diagnosis of type 2 myocardial infarction was not associated with increased in-patient mortality; however, few patients received invasive management that may have confirmed the diagnosis. Further research is needed to identify what type of intervention, if any, may improve outcomes in this patient population.

Preoperative ß-Blocker Therapy and Stroke or Major Adverse Cardiac Events in Major Abdominal Surgery: A Retrospective Cohort Study.

BACKGROUND: Perioperative ß-blocker therapy has been associated with increased risk of stroke. However, the association between ß-blocker initiation before the day of surgery and the risk of stroke is unknown. The authors hypothesized there would be no association between preoperative ß-blocker initiation within 60 days of surgery or chronic ß-blockade (more than 60 days) and the risk of stroke in patients undergoing major abdominal surgery. METHODS: Data on elective major abdominal surgery were obtained from the IBM (USA) Truven Health MarketScan 2005 to 2015 Commercial and Medicare Supplemental Databases. Patients were stratified by ß-blocker dispensing exposure: (1) ß-blocker-naïve, (2) preoperative ß-blocker initiation within 60 days of surgery, and (3) chronic ß-blocker dispensing (more than 60 days). The authors compared in-hospital stroke and major adverse cardiac events between the different ß-blocker therapy exposures. RESULTS: There were 204,981 patients who underwent major abdominal surgery. ß-Blocker exposure was as follows: perioperative initiation within 60 days of surgery for 4,026 (2.0%) patients, chronic ß-blocker therapy for 45,424 (22.2%) patients, and ß-blocker-naïve for 155,531 (75.9%) patients. The unadjusted frequency of stroke for patients with ß-blocker initiation (0.4%, 17 of 4,026) and chronic ß-blocker therapy (0.4%, 171 of 45,424) was greater than in ß-blocker-naïve patients (0.2%, 235 of 155,531; P < 0.001). After propensity score weighting, patients initiated on a ß-blocker within 60 days of surgery (odds ratio, 0.90; 95% CI, 0.31 to 2.04; P = 0.757) or on chronic ß-blocker therapy (odds ratio, 0.86; 95% CI, 0.65 to 1.15; P = 0.901) demonstrated similar stroke risk compared to ß-blocker-naïve patients. Patients on chronic ß-blocker therapy demonstrated lower adjusted risk of major adverse cardiac events compared to ß-blocker-naïve patients (odds ratio, 0.81; 95% CI, 0.72 to 0.91; P = 0.007), despite higher unadjusted absolute event rate (2.6% [1,173 of 45,424] vs. 0.6% [872 of 155,531]). CONCLUSIONS: Among patients undergoing elective major abdominal surgery, the authors observed no association between preoperative ß-blocker initiation within 60 days of surgery or chronic ß-blocker therapy and stroke.

Preoperative Assessment of Anxiety and Depression Using Computerized Adaptive Screening Tools: A Pilot Prospective Cohort Study.

BACKGROUND: Serious mental health conditions (eg, anxiety and depression) are common in surgical patients, yet likely underassessed due to the time-consuming and cumbersome traditional screening process. A recently developed computerized adaptive mental health assessment tool (computerized adaptive test-mental health [CAT-MH]) allows rapid, precise, and accurate assessment of numerous mental health disorders, including anxiety and depression, without the need for a trained interviewer. The goal of this investigation was to determine the feasibility of administering CAT-MH for anxiety and depression in the preoperative setting and to obtain preliminary evidence of the prevalence of anxiety and depression in preoperative patients. METHODS: In this prospective cohort study, 100 adult patients scheduled for elective surgery were enrolled and asked to complete the CAT-MH in the preoperative clinic. Urgent and emergency surgeries were excluded as were pregnant patients. Primary feasibility outcomes were completion rate and time to completion. Secondary outcomes were prevalence estimates of anxiety and depression. RESULTS: All 100 enrolled patients completed the study. All patients were able to complete the mental health assessment (mean time: 3.6 ± 1.8 minutes standard deviation). Sixteen patients (16%) screened positive for anxiety (severity: mild, n = 7 [7%]; moderate, n = 7 [7%]); severe, n = 2 [2%]); 12 of 16 (75%) did not have a previous diagnosis of anxiety disorder. Twenty-eight (28%) patients screened positive for depression (severity: mild, n = 26 [26%]; moderate and severe, n = 1 each [1%]); 23 of 28 (82%) had no previous diagnosis of depressive disorder. Nineteen patients (19%) met the screening criteria for major depressive disorder; 14 of 19 (74%) of which had no previous diagnosis of major depressive disorder. CONCLUSIONS: The results of this pilot study support the feasibility of using CAT-MH in a preoperative evaluation and indicate that there is a substantial prevalence of undiagnosed anxiety and depression in surgical patients.

Evaluation of Appropriate Use of Preoperative Echocardiography before Major Abdominal Surgery: A Retrospective Cohort Study.

BACKGROUND: Preoperative resting echocardiography is often performed before noncardiac surgery, but indications for preoperative resting echocardiography are limited. This study aimed to investigate appropriateness of preoperative resting echocardiography using the Appropriate Use Criteria for Echocardiography, which encompass indications from the guidelines on perioperative cardiovascular evaluation and management and nonperioperative indications independent of the perioperative period. The authors hypothesized that patients are frequently tested without an appropriate indication. METHODS: Records of patients in the Truven Health MarketScan Commercial and Medicare Supplemental Databases who underwent a major abdominal surgery from 2005 to 2017 were included. These databases contain de-identified records of health services for more than 250 million patients with primary or Medicare supplemental health insurance coverage through employer-based fee-for-service, point-of-service, or capitated plans. Patients were classified based on the presence of an outpatient claim for resting transthoracic echocardiography within 60 days of surgery. Appropriateness was determined via International Classification of Diseases, Ninth Revision-Clinical Modification, and International Classification of Diseases, Tenth Revision-Clinical Modification principal and secondary diagnosis codes associated with the claims, and classified as "appropriate," "rarely appropriate," or "unclassifiable" using the Appropriate Use Criteria for Echocardiography. RESULTS: Among 230,535 patients in the authors' cohort, preoperative resting transthoracic echocardiography was performed in 6.0% (13,936) of patients. There were 12,638 (91%) studies classifiable by the Appropriate Use Criteria for Echocardiography, and 1,298 (9%) were unable to be classified. Among the classifiable studies, 8,959 (71%) were deemed "appropriate," while 3,679 (29%) were deemed "rarely appropriate." Surveillance of chronic ischemic heart disease and uncomplicated hypertension accounted for 43% (1,588 of 3,679) of "rarely appropriate" echocardiograms. CONCLUSIONS: More than one in four preoperative resting echocardiograms were considered "rarely appropriate" according to the Appropriate Use Criteria for Echocardiography. A narrow set of patient characteristics accounts for a large proportion of "rarely appropriate" preoperative resting echocardiograms.

Systematic review and consensus definitions for the Standardized Endpoints in Perioperative Medicine (StEP) initiative: cardiovascular outcomes.

BACKGROUND: Adverse cardiovascular events are a leading cause of perioperative morbidity and mortality. The definitions of perioperative cardiovascular adverse events are heterogeneous. As part of the international Standardized Endpoints in Perioperative Medicine initiative, this study aimed to find consensus amongst clinical trialists on a set of standardised and valid cardiovascular outcomes for use in future perioperative clinical trials. METHODS: We identified currently used perioperative cardiovascular outcomes by a systematic review of the anaesthesia and perioperative medicine literature (PubMed/Ovid, Embase, and Cochrane Library). We performed a three-stage Delphi consensus-gaining process that involved 55 clinician researchers worldwide. Cardiovascular outcomes were first shortlisted and the most suitable definitions determined. These cardiovascular outcomes were then assessed for validity, reliability, feasibility, and clarity. RESULTS: We identified 18 cardiovascular outcomes. Participation in the three Delphi rounds was 100% (n=19), 71% (n=55), and 89% (n=17), respectively. A final list of nine cardiovascular outcomes was elicited from the consensus: myocardial infarction, myocardial injury, cardiovascular death, non-fatal cardiac arrest, coronary revascularisation, major adverse cardiac events, pulmonary embolism, deep vein thrombosis, and atrial fibrillation. These nine cardiovascular outcomes were rated by the majority of experts as valid, reliable, feasible, and clearly defined. CONCLUSIONS: These nine consensus cardiovascular outcomes can be confidently used as endpoints in clinical trials designed to evaluate perioperative interventions with the goal of improving perioperative outcomes.

Morbidity and Mortality After Acute Myocardial Infarction After Elective Major Noncardiac Surgery.

OBJECTIVES: To develop parsimonious models of in-hospital mortality and morbidity risk after perioperative acute myocardial infarction (AMI). DESIGN: Retrospective data analysis. SETTING: National Inpatient Sample (2008-2013), a 20% sample of all non-federal in-patient hospitalizations in the United States. PARTICIPANTS: Patients 45 years or older who experienced perioperative AMI during elective admission for noncardiac surgery. INTERVENTIONS: The study used a mixed principal components analysis and multivariate logistic regression to identify risk factors for in-hospital mortality after perioperative AMI. A model incorporating only preoperative risk factors, defined by the Revised Cardiac Risk Index (RCRI), was compared with a "full risk factor" model, incorporating a large set of preoperative AMI risk factors. The risk of post-AMI disposition to an intermediate care or skilled nursing facility, a marker of functional impairment, then was evaluated. MEASUREMENTS AND MAIN RESULTS: In the present study, 15,574 cases of AMI after elective noncardiac surgery were identified (0.42%, corresponding with 78,122 cases nationally), with a 12.4% in-hospital mortality rate. The "RCRI-only" model was the best-fit model of post-AMI in-hospital mortality risk, without loss of predictive accuracy compared with the "full risk factor" model (area under the receiver operator characteristic curve 0.80, 95% confidence interval [CI] [0.77-0.82] v area under the receiver operator characteristic curve 0.81, 95% CI [0.77-0.83], respectively). Post-AMI mortality risk was the highest for perioperative complications, including sepsis (odds ratio 4.95, 95% CI [4.32-5.67]). Conversely, functional impairment was best predicted by the "full-risk factor" model and depended strongly on chronic preoperative comorbidities. CONCLUSIONS: The RCRI provides a simple but adequate model of preoperative risk factors for in-hospital mortality after perioperative AMI.

Expert consensus on peri-operative myocardial injury screening in noncardiac surgery: A literature review.

Peri-operative myocardial injury, detected by dynamic and elevated cardiac troponin (cTn) concentrations, is a common complication of noncardiac surgery that is strongly associated with 30-day mortality. Although active screening for peri-operative myocardial injury has been suggested in recent guidelines, clinical implementation remains tentative due to a lack of examples on how to tackle such an interdisciplinary project at a local level. Moreover, consensus on which assay and cTn cut-off values should be used has not yet been reached, and guidance on whom to screen is lacking. In this article, we aim to summarise local examples of successfully implemented cTn screening practices and review the current literature in order to provide information and suggestions for patient selection, organisation of a screening programme, caveats and a potential management pathway.

Generalisability of randomised trials evaluating perioperative ß-blocker therapy in noncardiac surgery.

BACKGROUND: The limited applicability of evidence from RCTs in real-word practice is considered a potential bottleneck for evidence-based practice but rarely systematically assessed. Using our failure to recruit patients into a perioperative beta-blocker trial, we set out to analyse the restrictiveness and generalisability of trial eligibility criteria in a real-world cohort. METHODS: We prospectively included adult patients (≥18 yr) scheduled for elective noncardiac surgery at an academic tertiary care facility who were screened for inclusion in a planned perioperative beta-blocker RCT, which was terminated owing to recruitment failure. The primary outcome was the proportion of screened patients who matched the eligibility criteria of 36 published RCTs included in a large Cochrane meta-analysis on perioperative beta-blocker therapy. The pragmatic/explanatory level of each RCT was assessed using the PRagmatic-Explanatory Continuum Indicator Summary 2 (PRECIS-2) score, which ranges from 9 points (indicating a very explanatory study) to 45 points (indicating a very pragmatic study). RESULTS: A total of 2241 patients (54% female, n=1215; 52 [standard deviation, 20] yr) were included for the assessment of trial eligibility between October 2015 and January 2016. Only a small proportion of patients matched the inclusion and exclusion criteria for each of the 36 RCTs, ranging from 53% to 0%. The average proportion of patients who did match the eligibility criteria of all 36 RCTs was 6.5% (n=145; 95% confidence interval, 6.3-6.6). A higher PRECIS-2 score was associated with a higher proportion of matching patients (P<0.001). CONCLUSIONS: Trial eligibility criteria in perioperative beta-blocker therapy trials are overly restrictive and not generalisable to a real-world surgical population. CLINICAL TRIAL REGISTRATION: EudraCT#: 2015-002366-23.

Major Adverse Cardiac Events and Mortality Associated with Electroconvulsive Therapy: A Systematic Review and Meta-analysis.

BACKGROUND: Cardiac events after electroconvulsive therapy have been reported sporadically, but a systematic assessment of the risk is missing. The goal of this study was to obtain a robust estimate of the incidence of major adverse cardiac events in adult patients undergoing electroconvulsive therapy. METHODS: Systematic review and meta-analysis of studies that investigated electroconvulsive therapy and reported major adverse cardiac events and/or mortality. Endpoints were incidence rates of major adverse cardiac events, including myocardial infarction, arrhythmia, pulmonary edema, pulmonary embolism, acute heart failure, and cardiac arrest. Additional endpoints were all-cause and cardiac mortality. The pooled estimated incidence rates and 95% CIs of individual major adverse cardiac events and mortality per 1,000 patients and per 1,000 electroconvulsive therapy treatments were calculated. RESULTS: After screening of 2,641 publications and full-text assessment of 284 studies, the data of 82 studies were extracted (total n = 106,569 patients; n = 786,995 electroconvulsive therapy treatments). The most commonly reported major adverse cardiac events were acute heart failure, arrhythmia, and acute pulmonary edema with an incidence (95% CI) of 24 (12.48 to 46.13), 25.83 (14.83 to 45.00), and 4.92 (0.85 to 28.60) per 1,000 patients or 2.44 (1.27 to 4.69), 4.66 (2.15 to 10.09), and 1.50 (0.71 to 3.14) per 1,000 electroconvulsive therapy treatments. All-cause mortality was 0.42 (0.11 to 1.52) deaths per 1,000 patients and 0.06 (0.02 to 0.23) deaths per 1,000 electroconvulsive therapy treatments. Cardiac death accounted for 29% (23 of 79) of deaths. CONCLUSIONS: Major adverse cardiac events and death after electroconvulsive therapy are infrequent and occur in about 1 of 50 patients and after about 1 of 200 to 500 electroconvulsive therapy treatments.

Accuracy of Physical Function Questions to Predict Moderate-Vigorous Physical Activity as Measured by Hip Accelerometry.

BACKGROUND: Functional capacity assessment is a core component of current perioperative cardiovascular evaluation and management guidelines for noncardiac surgery. The authors investigated the ability of standardized physical function questions to predict whether participants engaged in moderate physical activity as measured by hip accelerometers. METHODS: Participant responses to physical functioning questions and whether they engaged in moderate physical activity were extracted from the National Health and Nutrition Examination Survey (2003 to 2004 and 2005 to 2006). Physical activity intensity was measured using hip accelerometers. Adult participants with at least one Revised Cardiac Risk Index condition were included in the analysis. Standardized physical function questions were evaluated using a classification and regression tree analysis. Training and test datasets were randomly generated to create and test the analysis. RESULTS: Five hundred and twenty-two participants were asked the physical functioning questions and 378 of 522 (72.4%) had a bout of moderate-vigorous activity. Classification and regression tree analysis identified a "no difficulty" response to walking up 10 stairs and the ability to walk two to three blocks as the most sensitive questions to predict the presence of a 2-min bout of moderate activity. Participants with positive responses to both questions had a positive likelihood ratio of 3.7 and a posttest probability greater than 90% of a 2-min bout of moderate-vigorous activity. The sensitivity and specificity of positive responses to physical functioning questions in the pruned tree were 0.97 (95% CI, 0.94 to 0.98) and 0.16 (95% CI, 0.10 to 0.23) for training data, and 0.88 (95% CI, 0.75 to 0.96) and 0.10 (95% CI, 0.00 to 0.45) for the test data. Participants with at least one 2-min bout of moderate activity had a greater percentage of overall daily active time (35.4 ± 0.5 vs. 26.7 ± 1.2; P = 0.001) than those without. CONCLUSIONS: Standardized physical function questions are highly sensitive but poorly specific to identify patients who achieve moderate physical activity. Additional strategies to evaluate functional capacity should be considered.

European Society of Anaesthesiology Task Force on Nitrous Oxide: a narrative review of its role in clinical practice.

Nitrous oxide (N2O) is one of the oldest drugs still in use in medicine. Despite its superior pharmacokinetic properties, controversy remains over its continued use in clinical practice, reflecting in part significant improvements in the pharmacology of other anaesthetic agents and developing awareness of its shortcomings. This narrative review describes current knowledge regarding the clinical use of N2O based on a systematic and critical analysis of the available scientific literature. The pharmacological properties of N2O are reviewed in detail along with current evidence for the indications and contraindications of this drug in specific settings, both in perioperative care and in procedural sedation. Novel potential applications for N2O for the prevention or treatment of chronic pain and depression are also discussed. In view of the available evidence, we recommend that the supply of N2O in hospitals be maintained while encouraging its economic delivery using modern low flow delivery systems. Future research into its potential novel applications in prevention or treatment of chronic conditions should be pursued to better identify its role place in the developing era of precision medicine.

Exploring Nitrous Oxide as Treatment of Mood Disorders: Basic Concepts.

Nitrous oxide (laughing gas) has shown early promise as a rapidly acting antidepressant in patients with treatment-resistant major depression and is currently investigated in several clinical trials. Because nitrous oxide is rarely administered outside operating rooms or dental practices, most psychiatrists are not familiar with how nitrous oxide is administered in a medical setting and what regulations guide its use. The goal of this brief review was to educate psychiatrists about the basic concepts of nitrous oxide administration and pharmacology. Furthermore, common misconceptions about nitrous oxide will be discussed.

Etiology of Acute Coronary Syndrome after Noncardiac Surgery.

BACKGROUND: The objective of this investigation was to determine the etiology of perioperative acute coronary syndrome with a particular emphasis on thrombosis versus demand ischemia. METHODS: In this retrospective cohort study, adult patients were identified who underwent coronary angiography for acute coronary syndrome within 30 days of noncardiac surgery at a major tertiary hospital between January 2008 and July 2015. Angiograms were independently reviewed by two interventional cardiologists who were blinded to clinical data and outcomes. Acute coronary syndrome was classified as ST-elevation myocardial infarction, non-ST-elevation myocardial infarction, or unstable angina; myocardial infarctions were adjudicated as type 1 (plaque rupture), type 2 (demand ischemia), or type 4b (stent thrombosis). RESULTS: Among 215,077 patients screened, 146 patients were identified who developed acute coronary syndrome: 117 were classified as non-ST-elevation myocardial infarction (80.1%); 21 (14.4%) were classified as ST-elevation myocardial infarction, and 8 (5.5%) were classified as unstable angina. After coronary angiography, most events were adjudicated as demand ischemia (type 2 myocardial infarction, n = 106, 72.6%) compared to acute coronary thrombosis (type 1 myocardial infarction, n = 37, 25.3%) and stent thrombosis (type 4B, n = 3, 2.1%). Absent or only mild, nonobstructive coronary artery disease was found in 39 patients (26.7%). In 14 patients (9.6%), acute coronary syndrome was likely due to stress-induced cardiomyopathy. Aggregate 30-day and 1-yr mortality rates were 7 and 14%, respectively. CONCLUSIONS: The dominant mechanism of perioperative acute coronary syndrome in our cohort was demand ischemia. A subset of patients had no evidence of obstructive coronary artery disease, but findings were consistent with stress-induced cardiomyopathy.

High-sensitivity Cardiac Troponin Elevation after Electroconvulsive Therapy: A Prospective, Observational Cohort Study.

BACKGROUND: While electroconvulsive therapy is widely regarded as a lifesaving and safe procedure, evidence regarding its effects on myocardial cell injury is sparse. The objective of this investigation was to determine the incidence and magnitude of new cardiac troponin elevation after electroconvulsive therapy using a novel high-sensitivity cardiac troponin I assay. METHODS: This was a prospective cohort study in adult patients undergoing electroconvulsive therapy in a single academic center (up to three electroconvulsive therapy treatments per patient). The primary outcome was new high-sensitivity cardiac troponin I elevation after electroconvulsive therapy, defined as an increase of high-sensitivity cardiac troponin I greater than 100% after electroconvulsive therapy compared to baseline with at least one value above the limit of quantification (10 ng/l). Twelve-lead electrocardiogram and high-sensitivity cardiac troponin I values were obtained before and 15 to 30 min after electroconvulsive therapy; in a subset of patients, an additional 2-h high-sensitivity cardiac troponin I value was obtained. RESULTS: The final study population was 100 patients and a total of 245 electroconvulsive therapy treatment sessions. Eight patients (8 of 100; 8%) experienced new high-sensitivity cardiac troponin I elevation after electroconvulsive therapy with a cumulative incidence of 3.7% (9 of 245 treatments; one patient had two high-sensitivity cardiac troponin I elevations), two of whom had a non-ST-elevation myocardial infarction (incidence 2 of 245; 0.8%). Median high-sensitivity cardiac troponin I concentrations did not increase significantly after electroconvulsive therapy. Tachycardia and/or elevated systolic blood pressure developed after approximately two thirds of electroconvulsive therapy treatments. CONCLUSIONS: Electroconvulsive therapy appears safe from a cardiac standpoint in a large majority of patients. A small subset of patients with preexisting cardiovascular risk factors, however, may develop new cardiac troponin elevation after electroconvulsive therapy, the clinical relevance of which is unclear in the absence of signs of myocardial ischemia.

High-Sensitivity Cardiac Troponin T Improves the Diagnosis of Perioperative MI.

BACKGROUND: The diagnosis of myocardial infarction (MI) after noncardiac surgery has traditionally relied on using relatively insensitive contemporary cardiac troponin (cTn) assays. We hypothesized that using a recently introduced novel high-sensitivity cTnT (hscTnT) assay would increase the detection rate of perioperative MI. METHODS: In this ancillary study of the Vitamins in Nitrous Oxide trial, readjudicated incidence rates of myocardial injury (new isolated cTn elevation) and MI were compared when diagnosed by contemporary cTnI versus hscTnT. We probed various relative (eg, >50%) or absolute (eg, +5 ng/L) hscTnT change metrics. Inclusion criteria for this ancillary study were the presence of a baseline and at least 1 postoperative hscTnT value. RESULTS: Among 605 patients, 70 patients (12%) had electrocardiogram changes consistent with myocardial ischemia; 82 patients (14%) had myocardial injury diagnosed by contemporary cTnI, 31 (5.1%) of which had an adjudicated MI. After readjudication, 67 patients (11%) were diagnosed with MI when using hscTnT, a 2-fold increase. Incidence rates of postoperative myocardial injury ranged from 12% (n = 73) to 65% (n = 393) depending on the hscTnT metric used. Incidence rates of MI using various hscTnT change metrics and the presence of ischemic electrocardiogram changes, but without event adjudication, ranged from 3.6% (n = 22) to 12% (n = 74), a >3-fold difference. New postoperative hscTnT elevation, either by absolute or relative hscTnT change metric, was associated with an up to 5-fold increase in 6-month mortality. CONCLUSIONS: The use of hscTnT compared to contemporary cTnI increases the detection rate of perioperative MI by a factor of 2. Using different absolute or relative hscTnT change metrics may lead to under- or overdiagnosis of perioperative MI.

Improving Prediction of Postoperative Myocardial Infarction With High-Sensitivity Cardiac Troponin T and NT-proBNP.

BACKGROUND: This study sought to determine whether preoperatively measured high-sensitivity cardiac troponin T (hs-cTnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP) improve cardiac risk prediction in patients undergoing major noncardiac surgery compared with the standard risk indices. METHODS: In this ancillary study to the Vitamins in Nitrous Oxide trial, patients were included who had preoperative hs-cTnT and NT-proBNP measured (n = 572). Study outcome was the incidence of postoperative myocardial infarction (MI) within the first 3 postoperative days. hs-cTnT was considered elevated if >14 ng/L and NT-proBNP if >300 ng/L. Additional cutoff values were investigated on the basis of receiver operating characteristic statistics. Biomarker risk prediction was compared with Lee's Revised Cardiac Risk Index (RCRI) with the use of standard methods and net reclassification index. RESULTS: The addition of hs-cTnT (>14 ng/L) and NT-proBNP (>300 ng/L) to RCRI significantly improved the prediction of postoperative MI (event rate 30/572 [5.2%], Area under the receiver operating characteristic curve increased from 0.590 to 0.716 with a 0.66 net reclassification index [95% confidence interval 0.32-0.99], P < .001). The use of 108 ng/L as a cutoff for NT-proBNP improved sensitivity compared with 300 ng/L (0.87 vs 0.53). Sensitivity, specificity, positive, and negative predictive value for hs-cTnT were 0.70, 0.60, 0.09, and 0.97 and for NT-proBNP were 0.53, 0.68, 0.08, and 0.96. CONCLUSIONS: The addition of cardiac biomarkers hs-cTnT and NT-proBNP to RCRI improves the prediction of adverse cardiac events in the immediate postoperative period after major noncardiac surgery. The high negative predictive value of preoperative hs-cTnT and NT-proBNP suggest usefulness as a "rule-out" test to confirm low risk of postoperative MI.

Influence of EMS-physician presence on survival after out-of-hospital cardiopulmonary resuscitation: systematic review and meta-analysis.

BACKGROUND: Evidence suggests that EMS-physician-guided cardiopulmonary resuscitation (CPR) in out-of-hospital cardiac arrest (OOHCA) may be associated with improved outcomes, yet randomized controlled trials are not available. The goal of this meta-analysis was to determine the association between EMS-physician- versus paramedic-guided CPR and survival after OOHCA. METHODS AND RESULTS: Studies that compared EMS-physician- versus paramedic-guided CPR in OOHCA published until June 2014 were systematically searched in MEDLINE, EMBASE and Cochrane databases. All studies were required to contain survival data. Data on study characteristics, methods, and as well as survival outcomes were extracted. A random-effects model was used for the meta-analysis due to a high degree of heterogeneity among the studies (I(2) = 44%). Return of spontaneous circulation [ROSC], survival to hospital admission, and survival to hospital discharge were the outcome measures. Out of 3,385 potentially eligible studies, 14 met the inclusion criteria. In the pooled analysis (n = 126,829), EMS-physician-guided CPR was associated with significantly improved outcomes compared to paramedic-guided CPR: ROSC 36.2% (95% confidence interval [CI] 31.0 - 41.7%) vs. 23.4% (95% CI 18.5 - 29.2%) (pooled odds ratio [OR] 1.89, 95% CI 1.36 - 2.63, p < 0.001); survival to hospital admission 30.1 % (95% CI 24.2 - 36.7%) vs. 19.2% (95% CI 12.7 - 28.1%) (pooled OR 1.78, 95% CI 0.97 - 3.28, p = 0.06); and survival to discharge 15.1% (95% CI 14.6 - 15.7%) vs. 8.4% (95% CI 8.2 - 8.5%) (pooled OR 2.03, 95% CI 1.48 - 2.79, p < 0.001). CONCLUSIONS: This systematic review suggests that EMS-physician-guided CPR in out-of-hospital cardiac arrest is associated with improved survival outcomes.