Tranexamic Acid in Patients Undergoing Noncardiac Surgery.

BACKGROUND: Perioperative bleeding is common in patients undergoing noncardiac surgery. Tranexamic acid is an antifibrinolytic drug that may safely decrease such bleeding. METHODS: We conducted a trial involving patients undergoing noncardiac surgery. Patients were randomly assigned to receive tranexamic acid (1-g intravenous bolus) or placebo at the start and end of surgery (reported here) and, with the use of a partial factorial design, a hypotension-avoidance or hypertension-avoidance strategy (not reported here). The primary efficacy outcome was life-threatening bleeding, major bleeding, or bleeding into a critical organ (composite bleeding outcome) at 30 days. The primary safety outcome was myocardial injury after noncardiac surgery, nonhemorrhagic stroke, peripheral arterial thrombosis, or symptomatic proximal venous thromboembolism (composite cardiovascular outcome) at 30 days. To establish the noninferiority of tranexamic acid to placebo for the composite cardiovascular outcome, the upper boundary of the one-sided 97.5% confidence interval for the hazard ratio had to be below 1.125, and the one-sided P value had to be less than 0.025. RESULTS: A total of 9535 patients underwent randomization. A composite bleeding outcome event occurred in 433 of 4757 patients (9.1%) in the tranexamic acid group and in 561 of 4778 patients (11.7%) in the placebo group (hazard ratio, 0.76; 95% confidence interval [CI], 0.67 to 0.87; absolute difference, -2.6 percentage points; 95% CI, -3.8 to -1.4; two-sided P<0.001 for superiority). A composite cardiovascular outcome event occurred in 649 of 4581 patients (14.2%) in the tranexamic acid group and in 639 of 4601 patients (13.9%) in the placebo group (hazard ratio, 1.02; 95% CI, 0.92 to 1.14; upper boundary of the one-sided 97.5% CI, 1.14; absolute difference, 0.3 percentage points; 95% CI, -1.1 to 1.7; one-sided P = 0.04 for noninferiority). CONCLUSIONS: Among patients undergoing noncardiac surgery, the incidence of the composite bleeding outcome was significantly lower with tranexamic acid than with placebo. Although the between-group difference in the composite cardiovascular outcome was small, the noninferiority of tranexamic acid was not established. (Funded by the Canadian Institutes of Health Research and others; POISE-3 ClinicalTrials.gov number, NCT03505723.).

High-Sensitivity Troponin I after Cardiac Surgery and 30-Day Mortality.

BACKGROUND: Consensus recommendations regarding the threshold levels of cardiac troponin elevations for the definition of perioperative myocardial infarction and clinically important periprocedural myocardial injury in patients undergoing cardiac surgery range widely (from >10 times to ≥70 times the upper reference limit for the assay). Limited evidence is available to support these recommendations. METHODS: We undertook an international prospective cohort study involving patients 18 years of age or older who underwent cardiac surgery. High-sensitivity cardiac troponin I measurements (upper reference limit, 26 ng per liter) were obtained 3 to 12 hours after surgery and on days 1, 2, and 3 after surgery. We performed Cox analyses using a regression spline that explored the relationship between peak troponin measurements and 30-day mortality, adjusting for scores on the European System for Cardiac Operative Risk Evaluation II (which estimates the risk of death after cardiac surgery on the basis of 18 variables, including age and sex). RESULTS: Of 13,862 patients included in the study, 296 (2.1%) died within 30 days after surgery. Among patients who underwent isolated coronary-artery bypass grafting or aortic-valve replacement or repair, the threshold troponin level, measured within 1 day after surgery, that was associated with an adjusted hazard ratio of more than 1.00 for death within 30 days was 5670 ng per liter (95% confidence interval [CI], 1045 to 8260), a level 218 times the upper reference limit. Among patients who underwent other cardiac surgery, the corresponding threshold troponin level was 12,981 ng per liter (95% CI, 2673 to 16,591), a level 499 times the upper reference limit. CONCLUSIONS: The levels of high-sensitivity troponin I after cardiac surgery that were associated with an increased risk of death within 30 days were substantially higher than levels currently recommended to define clinically important periprocedural myocardial injury. (Funded by the Canadian Institutes of Health Research and others; VISION Cardiac Surgery ClinicalTrials.gov number, NCT01842568.).

Hypotension-Avoidance Versus Hypertension-Avoidance Strategies in Noncardiac Surgery : An International Randomized Controlled Trial.

BACKGROUND: Among patients having noncardiac surgery, perioperative hemodynamic abnormalities are associated with vascular complications. Uncertainty remains about what intraoperative blood pressure to target and how to manage long-term antihypertensive medications perioperatively. OBJECTIVE: To compare the effects of a hypotension-avoidance and a hypertension-avoidance strategy on major vascular complications after noncardiac surgery. DESIGN: Partial factorial randomized trial of 2 perioperative blood pressure management strategies (reported here) and tranexamic acid versus placebo. (ClinicalTrials.gov: NCT03505723). SETTING: 110 hospitals in 22 countries. PATIENTS: 7490 patients having noncardiac surgery who were at risk for vascular complications and were receiving 1 or more long-term antihypertensive medications. INTERVENTION: In the hypotension-avoidance strategy group, the intraoperative mean arterial pressure target was 80 mm Hg or greater; before and for 2 days after surgery, renin-angiotensin-aldosterone system inhibitors were withheld and the other long-term antihypertensive medications were administered only for systolic blood pressures 130 mm Hg or greater, following an algorithm. In the hypertension-avoidance strategy group, the intraoperative mean arterial pressure target was 60 mm Hg or greater; all antihypertensive medications were continued before and after surgery. MEASUREMENTS: The primary outcome was a composite of vascular death and nonfatal myocardial injury after noncardiac surgery, stroke, and cardiac arrest at 30 days. Outcome adjudicators were masked to treatment assignment. RESULTS: The primary outcome occurred in 520 of 3742 patients (13.9%) in the hypotension-avoidance group and in 524 of 3748 patients (14.0%) in the hypertension-avoidance group (hazard ratio, 0.99 [95% CI, 0.88 to 1.12]; P = 0.92). Results were consistent for patients who used 1 or more than 1 antihypertensive medication in the long term. LIMITATION: Adherence to the assigned strategies was suboptimal; however, results were consistent across different adherence levels. CONCLUSION: In patients having noncardiac surgery, our hypotension-avoidance and hypertension-avoidance strategies resulted in a similar incidence of major vascular complications. PRIMARY FUNDING SOURCE: Canadian Institutes of Health Research, National Health and Medical Research Council (Australia), and Research Grant Council of Hong Kong.

Postdischarge opioid use after lumbar spine surgery among older adults in Ontario: a population-based cohort study.

BACKGROUND: Prescription opioid use places a considerable economic burden on health care systems. Older patients undergoing surgical procedures for painful conditions commonly receive opioids pre- and postoperatively, and are susceptible to adverse reactions. This study explores predictors of prolonged postoperative opioid use among older patients after lumbar spine surgery and the consequences in terms of health care utilization and costs. METHODS: We conducted a retrospective population-based cohort study using Ontario administrative data from older adults undergoing spine surgery between 2006 and 2017. Data were analyzed from 90 days preoperatively to 1 year after hospital discharge, with last postoperative opioid prescriptions stratified into 90-day increments. We used multivariable ordinal logistic regression to identify predictors of long-term opioid use and generalized linear modelling to examine resource utilization and health care costs (2021 Canadian dollars). RESULTS: Of 15 109 patients included, 40.8% received preoperative opioid prescriptions. Preoperative opioid use strongly predicted prolonged postoperative use (odds ratio [OR] 4.47, 95% confidence interval [CI] 4.16-4.79), with 48.3% of patients who received preoperative opioids continuing to use opioids for longer than 9 months, relative to 12.7% of those without preoperative use. Several other risk factors for prolonged use were identified. Patients receiving long-term postoperative opioids incurred greater health care costs relative to those with opioids prescribed for fewer than 90 days (OR 1.49, 95% CI 1.44-1.54). CONCLUSION: Among older adults undergoing spine surgery, preoperative opioid use was a strong predictor of prolonged postoperative use, which was associated with increased health care costs. These results form an important baseline for future studies evaluating strategies to reduce opioid use targeting older surgical populations.

Long-term opioid use in seniors following hip and knee arthroplasty in Ontario: a historical cohort study.

PURPOSE: Canadian seniors who undergo hip and knee arthroplasty often experience significant postoperative pain, which could result in persistent opioid use. We aimed to document the impact of preoperative opioid use and other characteristics on postoperative opioid prescriptions in elderly patients following hip and knee replacement before widespread dissemination of opioid reduction strategies. METHODS: We conducted a historical cohort study to evaluate postoperative opioid use in patients over 65 yr undergoing primary total hip and knee replacement over a ten-year period from 1 April 2006 to 31 March 2016, using linked de-identified Ontario administrative data. We determined the use of preoperative opioids and the duration of postoperative opioid prescriptions (short-term [1-90 days], prolonged [91-180 days], chronic [181-365 days], or undocumented). RESULTS: The study included 49,638 hip and 85,558 knee replacement patients. Eighteen percent of hip and 21% of knee replacement patients received an opioid prescription within 90 days before surgery. Postoperatively, 51% of patients filled opioid prescriptions for 1-90 days, while 24% of hip and 29% of knee replacement patients filled prescriptions between 6 and 12 months, with no impact of preoperative opioid use. Residence in long-term care was a significant predictor of chronic opioid use (hip: odds ratio [OR], 2.64; 95% confidence interval [CI], 1.93 to 3.59; knee: OR, 2.46; 95% CI, 1.75 to 3.45); other risk factors included female sex and increased comorbidities. CONCLUSION: Despite a main goal of joint arthroplasty being relief of pain, seniors commonly remained on postoperative opioids, even if not receiving opioids before surgery. Opioid reduction strategies need to be implemented at the surgical, primary physician, long-term care, and patient levels. These findings form a basis for future investigations following implementation of opioid reduction approaches.

RéSUMé: OBJECTIF: Les aînés canadiens subissant une arthroplastie de la hanche ou du genou éprouvent souvent une douleur postopératoire importante, ce qui pourrait entraîner la consommation persistante d'opioïdes. Nous avons cherché à documenter l'impact d'une utilisation préopératoire d'opioïdes et d'autres caractéristiques sur les prescriptions postopératoires d'opioïdes chez les patients âgés suivant un remplacement de hanche ou de genou avant l'utilisation répandue de stratégies de réduction d'opioïdes. MéTHODE: Nous avons réalisé une étude de cohorte historique pour évaluer la consommation postopératoire d'opioïdes chez les patients de plus de 65 ans subissant une arthroplastie totale primaire de la hanche ou du genou sur une période de dix ans du 1er avril 2006 au 31 mars 2016, à l'aide de données administratives dépersonnalisées et codées de l'Ontario. Nous avons déterminé la durée des ordonnances préopératoires et postopératoires d'opioïdes (à court terme [1-90 jours], prolongées [91-180 jours], chroniques [181-365 jours] ou non documentées). RéSULTATS: L'étude a porté sur 49 638 patients ayant subi une arthroplastie de la hanche et 85 558 patients une arthroplastie du genou. Dix-huit pour cent des patients ayant subi une arthroplastie de la hanche et 21 % des patients ayant subi une arthroplastie du genou ont reçu une ordonnance d'opioïdes dans les 90 jours précédant leur chirurgie. En période postopératoire, 51 % des patients ont utilisé leurs ordonnances d'opioïdes pendant 1 à 90 jours, tandis que 24 % des patients d'arthroplastie de la hanche et 29 % des patients d'arthroplastie du genou ont utilisé leurs ordonnances entre six et 12 mois. Le fait d'habiter dans un établissement de soins de longue durée était un prédicteur important de consommation chronique d'opioïdes (hanche : rapport de cotes [RC], 2,64; intervalle de confiance [IC] à 95 %, 1,93 à 3,59; genou : RC, 2,46; IC 95 %, 1,75 à 3,45); le sexe féminin et l'augmentation des comorbidités constituaient d'autres facteurs de risque. CONCLUSION: Bien que l'un des principaux objectifs de l'arthroplastie articulaire soit le soulagement de la douleur, les personnes âgées continuent généralement à consommer des opioïdes en période postopératoire, même si elles ne prenaient pas d'opioïdes avant leur chirurgie. Il est nécessaire de mettre en œuvre des stratégies de réduction des opioïdes qui s'adressent aux chirurgiens, aux médecins traitants, aux soins de longue durée et aux patients. Ces constatations constituent la base d'études futures réalisées à la suite de la mise en œuvre d'approches de réduction des opioïdes.

Chronic opioid use after joint replacement surgery in seniors is associated with increased healthcare utilization and costs: a historical cohort study.

PURPOSE: Postoperative opioid use may be associated with increased healthcare utilization and costs. We sought to examine the relationship between duration of postoperative opioid prescriptions and healthcare costs and resource utilization in senior patients following hip and knee replacement. METHODS: We conducted a historical cohort study evaluating postoperative opioid use and healthcare costs in patients over the age of 65 yr undergoing primary total hip or knee arthroplasty over a ten-year period from 1 April 2006 to 31 March 2016. The last follow-up date was 31 March 2017. We identified preoperative and postoperative opioid prescriptions, patient characteristics, and healthcare costs using deidentified Ontario administrative databases (Institute of Clinical Evaluative Sciences). Duration of postoperative opioid use was divided into four categories: short-term (1-90 days), prolonged (91-180 days), chronic (181-365 days), and undocumented. RESULTS: The study included 49,638 hip and 85,558 knee replacement patients. Although the initial hospitalization accounted for the greatest cost in all patients, over the following year patients in the short-term opioid use group incurred the lowest average costs, and those in the chronic group incurred the highest (hip, CAD 17,528 vs CAD 26,736; knee, CAD 16,043 vs CAD 23,007), driven by increased healthcare resource utilization. CONCLUSION: Chronic opioid use after arthroplasty was associated with higher resource utilization and healthcare costs during the year following surgery. These results can be used to develop predictors of longer opioid use and higher costs. Further research is planned to determine whether recently implemented opioid reduction strategies can reduce healthcare resource utilization.

RéSUMé: OBJECTIF: L'utilisation postopératoire d'opioïdes peut être associée à une augmentation de l'utilisation et des coûts des soins de santé. Nous avons cherché à examiner la relation entre la durée des ordonnances d'opioïdes postopératoires, les coûts des soins de santé et l'utilisation des ressources chez les patients âgés après une arthroplastie de la hanche et du genou. MéTHODE: Nous avons réalisé une étude de cohorte historique évaluant la consommation postopératoire d'opioïdes et les coûts des soins de santé chez les patients de plus de 65 ans subissant une arthroplastie totale primaire de la hanche ou du genou sur une période de dix ans allant du 1er avril 2006 au 31 mars 2016. La dernière date de suivi était le 31 mars 2017. Nous avons identifié les ordonnances pré- et postopératoires d'opioïdes, les caractéristiques des patients et les coûts des soins de santé à l'aide de bases de données administratives de l'Ontario désidentifiées (ICES). La durée de la consommation d'opioïdes postopératoires était divisée en quatre catégories : à court terme (1 à 90 jours), prolongée (91 à 180 jours), chronique (181 à 365 jours) et non documentée. RéSULTATS: L'étude a porté sur 49 638 patients ayant subi une arthroplastie de la hanche et 85 558 patients une arthroplastie du genou. Bien que l'hospitalisation initiale ait représenté le coût le plus élevé chez tous les patients, au cours de l'année suivante, les patients du groupe de consommation d'opioïdes à court terme ont encouru les coûts moyens les plus bas et ceux du groupe chronique les coûts les plus élevés (hanche, 17 528 CAD vs 26 736 CAD; genou, 16 043 CAD vs 23 007 CAD) en raison de l'utilisation accrue des ressources de soins de santé. CONCLUSION: La consommation chronique d'opioïdes après une arthroplastie a été associée à une augmentation de l'utilisation des ressources et des coûts des soins de santé au cours de l'année suivant la chirurgie. Ces résultats peuvent être utilisés pour développer des modèles de prédiction d'une consommation prolongée d'opioïdes et de coûts plus élevés. D'autres recherches sont prévues pour déterminer si les stratégies de réduction de la consommation d'opioïdes récemment mises en œuvre pourront réduire l'utilisation des ressources en soins de santé.

Risk of stroke and other adverse outcomes in patients with perioperative atrial fibrillation 1 year after non-cardiac surgery.

AIMS: To determine the 1-year risk of stroke and other adverse outcomes in patients with a new diagnosis of perioperative atrial fibrillation (POAF) after non-cardiac surgery. METHODS AND RESULTS: The PeriOperative ISchemic Evaluation (POISE)-1 trial evaluated the effects of metoprolol vs. placebo in 8351 patients, and POISE-2 compared the effect of aspirin vs. placebo, and clonidine vs. placebo in 10 010 patients. These trials included patients with, or at risk of, cardiovascular disease who were undergoing non-cardiac surgery. For the purpose of this study, we combined the POISE datasets, excluding 244 patients who were in atrial fibrillation (AF) at the time of randomization. Perioperative atrial fibrillation was defined as new AF that occurred within 30 days after surgery. Our primary outcome was the incidence of stroke at 1 year of follow-up; secondary outcomes were mortality and myocardial infarction (MI). We compared outcomes among patients with and without POAF using multivariable adjusted Cox proportional hazards models. Among 18 117 patients (mean age 69 years, 57.4% male), 404 had POAF (2.2%). The stroke incidence 1 year after surgery was 5.58 vs. 1.54 per 100 patient-years in patients with and without POAF, adjusted hazard ratio (aHR) 3.43, 95% confidence interval (CI) 2.00-5.90; P < 0.001. Patients with POAF also had an increased risk of death (incidence 31.37 vs. 9.34; aHR 2.51, 95% CI 2.01-3.14; P < 0.001) and MI (incidence 26.20 vs. 8.23; aHR 5.10, 95% CI 3.91-6.64; P < 0.001). CONCLUSION: Patients with POAF have a significantly increased risk of stroke, MI, and death at 1 year. Intervention studies are needed to evaluate risk reduction strategies in this high-risk population.

One-year Results of a Factorial Randomized Trial of Aspirin versus Placebo and Clonidine versus Placebo in Patients Having Noncardiac Surgery.

BACKGROUND: The authors previously reported that perioperative aspirin and/or clonidine does not prevent a composite of death or myocardial infarction 30 days after noncardiac surgery. Moreover, aspirin increased the risk of major bleeding and clonidine caused hypotension and bradycardia. Whether these complications produce harm at 1 yr remains unknown. METHODS: The authors randomized 10,010 patients with or at risk of atherosclerosis and scheduled for noncardiac surgery in a 1:1:1:1 ratio to clonidine/aspirin, clonidine/aspirin placebo, clonidine placebo/aspirin, or clonidine placebo/aspirin placebo. Patients started taking aspirin or placebo just before surgery; those not previously taking aspirin continued daily for 30 days, and those taking aspirin previously continued for 7 days. Patients were also randomly assigned to receive clonidine or placebo just before surgery, with the study drug continued for 72 h. RESULTS: Neither aspirin nor clonidine had a significant effect on the primary 1-yr outcome, a composite of death or nonfatal myocardial infarction, with a 1-yr hazard ratio for aspirin of 1.00 (95% CI, 0.89 to 1.12; P = 0.948; 586 patients [11.8%] vs. 589 patients [11.8%]) and a hazard ratio for clonidine of 1.07 (95% CI, 0.96 to 1.20; P = 0.218; 608 patients [12.1%] vs. 567 patients [11.3%]), with effect on death or nonfatal infarction. Reduction in death and nonfatal myocardial infarction from aspirin in patients who previously had percutaneous coronary intervention at 30 days persisted at 1 yr. Specifically, the hazard ratio was 0.58 (95% CI, 0.35 to 0.95) in those with previous percutaneous coronary intervention and 1.03 (95% CI, 0.91to 1.16) in those without (interaction P = 0.033). There was no significant effect of either drug on death, cardiovascular complications, cancer, or chronic incisional pain at 1 yr (all P > 0.1). CONCLUSIONS: Neither perioperative aspirin nor clonidine have significant long-term effects after noncardiac surgery. Perioperative aspirin in patients with previous percutaneous coronary intervention showed persistent benefit at 1 yr, a plausible sub-group effect.

Aspirin in Patients With Previous Percutaneous Coronary Intervention Undergoing Noncardiac Surgery.

Background: Uncertainty remains about the effects of aspirin in patients with prior percutaneous coronary intervention (PCI) having noncardiac surgery. Objective: To evaluate benefits and harms of perioperative aspirin in patients with prior PCI. Design: Nonprespecified subgroup analysis of a multicenter factorial trial. Computerized Internet randomization was done between 2010 and 2013. Patients, clinicians, data collectors, and outcome adjudicators were blinded to treatment assignment. (ClinicalTrials.gov: NCT01082874). Setting: 135 centers in 23 countries. Patients: Adults aged 45 years or older who had or were at risk for atherosclerotic disease and were having noncardiac surgery. Exclusions were placement of a bare-metal stent within 6 weeks, placement of a drug-eluting stent within 1 year, or receipt of nonstudy aspirin within 72 hours before surgery. Intervention: Aspirin therapy (overall trial, n = 4998; subgroup, n = 234) or placebo (overall trial, n = 5012; subgroup, n = 236) initiated within 4 hours before surgery and continued throughout the perioperative period. Of the 470 subgroup patients, 99.9% completed follow-up. Measurements: The 30-day primary outcome was death or nonfatal myocardial infarction; bleeding was a secondary outcome. Results: In patients with prior PCI, aspirin reduced the risk for the primary outcome (absolute risk reduction, 5.5% [95% CI, 0.4% to 10.5%]; hazard ratio [HR], 0.50 [CI, 0.26 to 0.95]; P for interaction = 0.036) and for myocardial infarction (absolute risk reduction, 5.9% [CI, 1.0% to 10.8%]; HR, 0.44 [CI, 0.22 to 0.87]; P for interaction = 0.021). The effect on the composite of major and life-threatening bleeding in patients with prior PCI was uncertain (absolute risk increase, 1.3% [CI, -2.6% to 5.2%]). In the overall population, aspirin increased the risk for major bleeding (absolute risk increase, 0.8% [CI, 0.1% to 1.6%]; HR, 1.22 [CI, 1.01 to 1.48]; P for interaction = 0.50). Limitation: Nonprespecified subgroup analysis with small sample. Conclusion: Perioperative aspirin may be more likely to benefit rather than harm patients with prior PCI. Primary Funding Source: Canadian Institutes of Health Research.

Period-dependent Associations between Hypotension during and for Four Days after Noncardiac Surgery and a Composite of Myocardial Infarction and Death: A Substudy of the POISE-2 Trial.

BACKGROUND: The relative contributions of intraoperative and postoperative hypotension to perioperative morbidity remain unclear. We determined the association between hypotension and a composite of 30-day myocardial infarction and death over three periods: (1) intraoperative, (2) remaining day of surgery, and (3) during the initial four postoperative days. METHODS: This was a substudy of POISE-2, a 10,010-patient factorial-randomized trial of aspirin and clonidine for prevention of myocardial infarction. Clinically important hypotension was defined as systolic blood pressure less than 90 mmHg requiring treatment. Minutes of hypotension was the exposure variable intraoperatively and for the remaining day of surgery, whereas hypotension status was treated as binary variable for postoperative days 1 to 4. We estimated the average relative effect of hypotension across components of the composite using a distinct effect generalized estimating model, adjusting for hypotension during earlier periods. RESULTS: Among 9,765 patients, 42% experienced hypotension, 590 (6.0%) had an infarction, and 116 (1.2%) died within 30 days of surgery. Intraoperatively, the estimated average relative effect across myocardial infarction and mortality was 1.08 (98.3% CI, 1.03, 1.12; P < 0.001) per 10-min increase in hypotension duration. For the remaining day of surgery, the odds ratio was 1.03 (98.3% CI, 1.01, 1.05; P < 0.001) per 10-min increase in hypotension duration. The average relative effect odds ratio was 2.83 (98.3% CI, 1.26, 6.35; P = 0.002) in patients with hypotension during the subsequent four days of hospitalization. CONCLUSIONS: Clinically important hypotension-a potentially modifiable exposure-was significantly associated with a composite of myocardial infarction and death during each of three perioperative periods, even after adjustment for previous hypotension.

Clonidine in patients undergoing noncardiac surgery.

BACKGROUND: Marked activation of the sympathetic nervous system occurs during and after noncardiac surgery. Low-dose clonidine, which blunts central sympathetic outflow, may prevent perioperative myocardial infarction and death without inducing hemodynamic instability. METHODS: We performed a blinded, randomized trial with a 2-by-2 factorial design to allow separate evaluation of low-dose clonidine versus placebo and low-dose aspirin versus placebo in patients with, or at risk for, atherosclerotic disease who were undergoing noncardiac surgery. A total of 10,010 patients at 135 centers in 23 countries were enrolled. For the comparison of clonidine with placebo, patients were randomly assigned to receive clonidine (0.2 mg per day) or placebo just before surgery, with the study drug continued until 72 hours after surgery. The primary outcome was a composite of death or nonfatal myocardial infarction at 30 days. RESULTS: Clonidine, as compared with placebo, did not reduce the number of primary-outcome events (367 and 339, respectively; hazard ratio with clonidine, 1.08; 95% confidence interval [CI], 0.93 to 1.26; P=0.29). Myocardial infarction occurred in 329 patients (6.6%) assigned to clonidine and in 295 patients (5.9%) assigned to placebo (hazard ratio, 1.11; 95% CI, 0.95 to 1.30; P=0.18). Significantly more patients in the clonidine group than in the placebo group had clinically important hypotension (2385 patients [47.6%] vs. 1854 patients [37.1%]; hazard ratio 1.32; 95% CI, 1.24 to 1.40; P<0.001). Clonidine, as compared with placebo, was associated with an increased rate of nonfatal cardiac arrest (0.3% [16 patients] vs. 0.1% [5 patients]; hazard ratio, 3.20; 95% CI, 1.17 to 8.73; P=0.02). CONCLUSIONS: Administration of low-dose clonidine in patients undergoing noncardiac surgery did not reduce the rate of the composite outcome of death or nonfatal myocardial infarction; it did, however, increase the risk of clinically important hypotension and nonfatal cardiac arrest. (Funded by the Canadian Institutes of Health Research and others; POISE-2 ClinicalTrials.gov number, NCT01082874.).

Aspirin in patients undergoing noncardiac surgery.

BACKGROUND: There is substantial variability in the perioperative administration of aspirin in patients undergoing noncardiac surgery, both among patients who are already on an aspirin regimen and among those who are not. METHODS: Using a 2-by-2 factorial trial design, we randomly assigned 10,010 patients who were preparing to undergo noncardiac surgery and were at risk for vascular complications to receive aspirin or placebo and clonidine or placebo. The results of the aspirin trial are reported here. The patients were stratified according to whether they had not been taking aspirin before the study (initiation stratum, with 5628 patients) or they were already on an aspirin regimen (continuation stratum, with 4382 patients). Patients started taking aspirin (at a dose of 200 mg) or placebo just before surgery and continued it daily (at a dose of 100 mg) for 30 days in the initiation stratum and for 7 days in the continuation stratum, after which patients resumed their regular aspirin regimen. The primary outcome was a composite of death or nonfatal myocardial infarction at 30 days. RESULTS: The primary outcome occurred in 351 of 4998 patients (7.0%) in the aspirin group and in 355 of 5012 patients (7.1%) in the placebo group (hazard ratio in the aspirin group, 0.99; 95% confidence interval [CI], 0.86 to 1.15; P=0.92). Major bleeding was more common in the aspirin group than in the placebo group (230 patients [4.6%] vs. 188 patients [3.8%]; hazard ratio, 1.23; 95% CI, 1.01, to 1.49; P=0.04). The primary and secondary outcome results were similar in the two aspirin strata. CONCLUSIONS: Administration of aspirin before surgery and throughout the early postsurgical period had no significant effect on the rate of a composite of death or nonfatal myocardial infarction but increased the risk of major bleeding. (Funded by the Canadian Institutes of Health Research and others; POISE-2 ClinicalTrials.gov number, NCT01082874.).

Clonidine Does Not Reduce Pain or Opioid Consumption After Noncardiac Surgery.

BACKGROUND: Clonidine is an α2-adrenoceptor agonist, which has analgesic properties. However, the analgesic efficacy of perioperative clonidine remains unclear. We, therefore, tested the hypothesis that clonidine reduces both pain scores and cumulative opioid consumption during the initial 72 hours after noncardiac surgery. METHODS: Six hundred twenty-four patients undergoing elective noncardiac surgery under general and spinal anesthesia were included in this substudy of the PeriOperative ISchemia Evaluation-2 trial. Patients were randomly assigned to 0.2 mg oral clonidine or placebo 2 to 4 hours before surgery, followed by 0.2 mg/d transdermal clonidine patch or placebo patch, which was maintained until 72 hours after surgery. Postoperative pain scores and opioid consumption were assessed for 72 hours after surgery. RESULTS: Clonidine had no effect on opioid consumption compared with placebo, with an estimated ratio of means of 0.98 (95% confidence interval, 0.70-1.38); P = 0.92. Median (Q1, Q3) opioid consumption was 63 (30, 154) mg morphine equivalents in the clonidine group, which was similar to 60 (30, 128) mg morphine equivalents in the placebo group. Furthermore, there was no significant effect on pain scores, with an estimated difference in means of 0.12 (95% confidence interval, -0.02 to 0.26); 11-point scale; P = 0.10. Mean pain scores per patient were 3.6 ± 1.8 for clonidine patients and 3.6 ± 1.8 for placebo patients. CONCLUSIONS: Clonidine does not reduce opioid consumption or pain scores in patients recovering from noncardiac surgery.

Preoperative beta blocker use associated with cerebral ischemia during carotid endarterectomy.

PURPOSE: Cerebral ischemia is a known complication of carotid cross-clamping during carotid endarterectomy. Selective intraluminal shunting for cerebral protection is not always effective and carries risks. The purpose of this study was to identify potentially modifiable risk factors for intraoperative cerebral ischemia and shunting during carotid endarterectomy. METHODS: We performed an historical case-control chart review of primary carotid endarterectomies with electroencephalographic (EEG) monitoring and selective shunting. Randomized controls and cases that showed ischemic EEG changes and required shunting were matched by year of surgery and the presence or absence of a contralateral carotid occlusion. Detailed perioperative data were collected for all cases. Results were analyzed using the Mantel-Haenszel test, analysis of variance, and a multivariate logistic regression model. RESULTS: Of 523 charts screened, 69 patients had experienced evidence of cerebral ischemia on clamping of the carotid and required shunting. These patients were more likely than their matched controls to have been receiving regular preoperative beta blockers (33/69 vs 18/69, respectively; P = 0.01; odds ratio [OR] 2.5; 95% confidence interval [CI] 1.2 to 5.1). Ipsilateral moderate carotid stenosis (60-80%) was also associated with increased risk. An adjusted multivariate regression model estimated an OR of 3.6 (95% CI 1.5 to 8.9; P = 0.005) for the association between use of a beta blocker and shunting. Intraoperative hemodynamic values were similar for the shunt and control groups as well as for patients receiving and not receiving preoperative beta blockers. CONCLUSION: The current study found an association between regular preoperative use of beta blockers and intraoperative cerebral ischemia in patients undergoing carotid endarterectomy. This effect did not relate to intraoperative hemodynamics.

Perioperative aspirin and clonidine and risk of acute kidney injury: a randomized clinical trial.

IMPORTANCE: Acute kidney injury, a common complication of surgery, is associated with poor outcomes and high health care costs. Some studies suggest aspirin or clonidine administered during the perioperative period reduces the risk of acute kidney injury; however, these effects are uncertain and each intervention has the potential for harm. OBJECTIVE: To determine whether aspirin compared with placebo, and clonidine compared with placebo, alters the risk of perioperative acute kidney injury. DESIGN, SETTING, AND PARTICIPANTS: A 2 × 2 factorial randomized, blinded, clinical trial of 6905 patients undergoing noncardiac surgery from 88 centers in 22 countries with consecutive patients enrolled between January 2011 and December 2013. INTERVENTIONS: Patients were assigned to take aspirin (200 mg) or placebo 2 to 4 hours before surgery and then aspirin (100 mg) or placebo daily up to 30 days after surgery, and were assigned to take oral clonidine (0.2 mg) or placebo 2 to 4 hours before surgery, and then a transdermal clonidine patch (which provided clonidine at 0.2 mg/d) or placebo patch that remained until 72 hours after surgery. MAIN OUTCOMES AND MEASURES: Acute kidney injury was primarily defined as an increase in serum creatinine concentration from the preoperative concentration by either an increase of 0.3 mg/dL or greater (≥26.5 µmol/L) within 48 hours of surgery or an increase of 50% or greater within 7 days of surgery. RESULTS: Aspirin (n = 3443) vs placebo (n = 3462) did not alter the risk of acute kidney injury (13.4% vs 12.3%, respectively; adjusted relative risk, 1.10; 95% CI, 0.96-1.25). Clonidine (n = 3453) vs placebo (n = 3452) did not alter the risk of acute kidney injury (13.0% vs 12.7%, respectively; adjusted relative risk, 1.03; 95% CI, 0.90-1.18). Aspirin increased the risk of major bleeding. In a post hoc analysis, major bleeding was associated with a greater risk of subsequent acute kidney injury (23.3% when bleeding was present vs 12.3% when bleeding was absent; adjusted hazard ratio, 2.20; 95% CI, 1.72-2.83). Similarly, clonidine increased the risk of clinically important hypotension. In a post hoc analysis, clinically important hypotension was associated with a greater risk of subsequent acute kidney injury (14.3% when hypotension was present vs 11.8% when hypotension was absent; adjusted hazard ratio, 1.34; 95% CI, 1.14-1.58). CONCLUSIONS AND RELEVANCE: Among patients undergoing major noncardiac surgery, neither aspirin nor clonidine administered perioperatively reduced the risk of acute kidney injury. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01082874.

A Frailty Index to Predict Mortality, Resource Utilization and Costs in Patients Undergoing Coronary Artery Bypass Graft Surgery in Ontario.

Background: People living with frailty are vulnerable to poor outcomes and incur higher health care costs after coronary artery bypass graft (CABG) surgery. Frailty-defining instruments for population-level research in the CABG setting have not been established. The objectives of the study were to develop a preoperative frailty index for CABG (pFI-C) surgery using Ontario administrative data; assess pFI-C suitability in predicting clinical and economic outcomes; and compare pFI-C predictive capabilities with other indices. Methods: A retrospective cohort study was conducted using health administrative data of 50,682 CABG patients. The pFI-C comprised 27 frailty-related health deficits. Associations between index scores and mortality, resource use and health care costs (2022 Canadian dollars [CAD]) were assessed using multivariable regression models. Capabilities of the pFI-C in predicting mortality were evaluated using concordance statistics; goodness of fit of the models was assessed using Akakie Information Criterion. Results: As assessed by the pFI-C, 22% of the cohort lived with frailty. The pFI-C score was strongly associated with mortality per 10% increase (odds ratio [OR], 3.04; 95% confidence interval [CI], [2.83,3.27]), and was significantly associated with resource utilization and costs. The predictive performances of the pFI-C, Charlson, and Elixhauser indices and Johns Hopkins Aggregated Diagnostic Groups were similar, and mortality models containing the pFI-C had a concordance (C)-statistic of 0.784. Cost models containing the pFI-C showed the best fit. Conclusions: The pFI-C is predictive of mortality and associated with resource utilization and costs during the year following CABG. This index could aid in identifying a subgroup of high-risk CABG patients who could benefit from targeted perioperative health care interventions.

Contexte: Les personnes dont l'état de santé est fragilisé sont susceptibles de connaître des issues défavorables et de générer des coûts plus élevés pour le système de santé après un pontage aortocoronarien. Aucun instrument n'a été établi pour définir la fragilité dans la recherche populationnelle en contexte de pontage aortocoronarien. Les objectifs de l'étude étaient les suivants : 1) concevoir un indice de fragilité préopératoire en vue d'un pontage aortocoronarien (preoperative frailty index for CABG surgery, pFI-C) en utilisant des données administratives de l'Ontario; 2) évaluer la capacité de cet indice à prédire les issues cliniques et économiques; et 3) comparer la valeur prédictive de cet indice avec celle d'autres indices. Méthodologie: Une étude de cohorte rétrospective a été menée à partir de données médico-administratives portant sur 50 682 patients ayant subi un pontage aortocoronarien. Le pFI-C comprenait 27 déficits de santé liés à la fragilité. Des liens entre les scores de l'indice et la mortalité, l'utilisation des ressources et les coûts de soins de santé (en $ CA de 2022) ont été évalués à l'aide de modèles de régression multivariable. La capacité du pFI-C à prédire la mortalité a été évaluée à l'aide de la statistique de concordance; la qualité de l'ajustement des modèles a été évaluée en fonction du critère d'information d'Akaike. Résultats: Selon l'évaluation par le pFI-C, 22 % de la cohorte vivait avec une fragilité. Le score de l'indice était fortement corrélé à la mortalité par tranche d'augmentation de 10 % (rapport de cotes de 3,04; intervalle de confiance à 95 % de 2,83 à 3,27) et était corrélé de manière significative à l'utilisation des ressources et aux coûts. La valeur prédictive du pFI-C, des indices de Charlson et Elixhauser, et de Johns Hopkins Aggregated Diagnostic Groups était similaire, et les modèles de mortalité contenant le pFI-C affichaient une valeur statistique C de 0,784. Les modèles de coûts contenant le pFI-C affichaient le meilleur ajustement. Conclusions: Le pFI-C est un facteur prédictif de mortalité et est corrélé à l'utilisation des ressources et aux coûts engagés durant l'année qui suit un pontage aortocoronarien. Cet indice pourrait faciliter la détection d'un sous-groupe de patients subissant un pontage aortocoronarien et présentant un risque élevé qui pourraient bénéficier de soins périopératoires ciblés.