Postoperative myocardial injury phenotypes and self-reported disability in patients undergoing noncardiac surgery: a multicentre observational study.

BACKGROUND: Postoperative myocardial injury (PMI) comprises a spectrum of mechanisms resulting in troponin release. The impact of different PMI phenotypes on postoperative disability remains unknown. METHODS: This was a multicentre prospective cohort study including patients aged ≥50 yr undergoing elective major noncardiac surgery. Patients were stratified in five groups based on the occurrence of PMI and clinical information on postoperative adverse events: PMI classified as myocardial infarction (MI; according to fourth definition), PMI plus adverse event other than MI, clinically silent PMI (PMI without adverse events), adverse events without PMI, and neither PMI nor an adverse event (reference). The primary endpoint was 6-month self-reported disability (assessed by WHO Disability Assessment Schedule 2.0 [WHODAS]). Disability-free survival was defined as WHODAS ≤16%. RESULTS: We included 888 patients of mean age 69 (range 53-91) yr, of which 356 (40%) were women; 151 (17%) patients experienced PMI, and 625 (71%) experienced 6-month disability-free survival. Patients with PMI, regardless of its phenotype, had higher preoperative disability scores than patients without PMI (difference in WHODAS; ß: 3.3, 95% confidence interval [CI]: 0.5-6.2), but scores remained stable after surgery (ß: 1.2, 95% CI: -3.2-5.6). Before surgery, patients with MI (n=36, 4%) were more disabled compared with patients without PMI and no adverse events (ß: 5.5, 95% CI: 0.3-10.8). At 6 months, patients with MI and patients without PMI but with adverse events worsened in disability score (ß: 11.2, 95% CI: 2.3-20.2; ß: 8.1, 95% CI: 3.0-13.2, respectively). Patients with clinically silent PMI did not change in disability score at 6 months (ß: 1.39, 95% CI: -4.50-7.29, P=0.642). CONCLUSIONS: Although patients with postoperative myocardial injury had higher preoperative self-reported disability, disability scores did not change at 6 months after surgery. However, patients experiencing myocardial infarction worsened in disability score after surgery.

Derivation and external validation of a 30-day mortality risk prediction model for older patients having emergency general surgery.

BACKGROUND: Older people (≥65 yr) are at increased risk of morbidity and mortality after emergency general surgery. Risk prediction models are needed to guide decision making in this high-risk population. Existing models have substantial limitations and lack external validation, potentially limiting their applicability in clinical use. We aimed to derive and validate, both internally and externally, a multivariable model to predict 30-day mortality risk in older patients undergoing emergency general surgery. METHODS: After protocol publication, we used the National Surgical Quality Improvement Program (NSQIP) database (2012-6; estimated to contain 90% data from the USA and 10% from Canada) to derive and internally validate a model to predict 30-day mortality for older people having emergency general surgery using logistic regression with elastic net regularisation. Internal validation was done with 10-fold cross-validation. External validation was done using a temporally separate health administrative database exclusively from Ontario, Canada. RESULTS: Overall, 6012 (12.0%) of the 50 221 patients died within 30 days. The model demonstrated strong discrimination (area under the curve [AUC]=0.871) and calibration across the spectrum of observed and predicted risks. Ten-fold internal cross-validation demonstrated minimal optimism (AUC=0.851, optimism 0.019 [standard deviation=0.06]) with excellent calibration. External validation demonstrated lower discrimination (AUC=0.700) and degraded calibration. CONCLUSION: A multivariable mortality risk prediction model was strongly discriminative and well calibrated internally. However, poor external validation suggests the model may not be generalisable to non-NSQIP data and hospitals. The findings highlight the importance of external validation before clinical application of risk models.

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.

Implementation of the Canadian Cardiovascular Society guidelines for perioperative risk assessment and management: an interrupted time series study.

PURPOSE: The Canadian Cardiovascular Society (CCS) guidelines for patients undergoing non-cardiac surgery address the lack of standardized management for patients at risk of perioperative cardiovascular complications. Our interdisciplinary group evaluated the implementation of these guidelines. METHODS: We used an interrupted time series design to evaluate the effect of implementation of the CCS guidelines, using routinely collected hospital data. The study population consisted of elective, non-cardiac surgery patients who were: i) inpatients following surgery and ii) age ≥ 65 or age 45-64 yr with a Revised Cardiac Risk Index ≥ 1. Outcomes included adherence to troponin I (TnI) monitoring (primary) and adherence to appropriate consultant care for patients with elevated TnI (secondary). Exploratory outcomes included cost measures and clinical outcomes such as length of stay. RESULTS: We included 1,421 patients (706 pre- and 715 post-implementation). We observed a 67% absolute increase (95% confidence interval, 55 to 80; P < 0.001) in adherence to TnI testing following the implementation of the guidelines. In patients who had elevated TnI following guideline implementation (n = 64), the majority (85%) received appropriate follow-up care in the form of a general medicine or cardiology consult, all received at least one electrocardiogram, and half received at least one advanced cardiac test (e.g., cardiac perfusion scan, or percutaneous intervention). CONCLUSIONS: Our study showed the ability to implement and adhere to the CCS guidelines. Large-scale multicentre evaluations of CCS guideline implementation are needed to gain a better understanding of potential effects on clinically relevant outcomes.

RéSUMé: OBJECTIF: Les lignes directrices de la Société canadienne de cardiologie (SCC) concernant les patients subissant une chirurgie non cardiaque ont été conçues pour pallier l'absence de standardisation dans la prise en charge des patients à risque de complications cardiovasculaires périopératoires. Notre groupe interdisciplinaire a évalué la mise en œuvre de ces lignes directrices. MéTHODE: Nous avons utilisé une méthodologie de série chronologique interrompue pour évaluer l'effet de la mise en œuvre des lignes directrices de la SCC, à l'aide des données hospitalières habituellement recueillies. La population à l'étude se composait de patients de chirurgies non cardiaques non urgentes qui étaient : i) hospitalisés après leur chirurgie et ii) âgés de ≥ 65 ans ou de 45 à 64 ans avec un Indice de risque cardiaque révisé ≥ 1. Les critères d'évaluation comprenaient l'observance du monitorage de la troponine I (TnI) (critère d'évaluation primaire) et l'observance des soins spécialisés appropriés aux patients présentant un taux élevé de TnI (critère secondaire). Les critères exploratoires comprenaient des mesures de coûts et des résultats cliniques tels que la durée de séjour. RéSULTATS: Nous avons inclus 1421 patients (706 avant et 715 après la mise en œuvre). Nous avons observé une augmentation absolue de 67 % (intervalle de confiance de 95 %, 55 à 80; P < 0,001) de l'observance des tests de la TnI suite à la mise en œuvre des lignes directrices. Parmi les patients présentant un taux élevé de TnI suite à la mise en œuvre des lignes directrices (n = 64), la majorité (85%) a reçu des soins de suivi appropriés sous la forme d'une consultation en médecine générale ou en cardiologie; tous ont subi au moins un électrocardiogramme, et la moitié ont passé au moins un examen cardiaque subséquent (p. ex., évaluation de la perfusion myocardique par scintigraphie ou cathétérisme percutané). CONCLUSION: Notre étude a montré qu'il est possible de mettre en œuvre et d'adhérer aux nouvelles lignes directrices de la SCC. Des évaluations multicentriques à grande échelle portant sur la mise en œuvre des lignes directrices de la SCC sont nécessaires pour mieux comprendre ses effets potentiels sur les devenirs cliniquement pertinents.

Hospital cost associated with anemia in elective colorectal surgery: a historical cohort study.

PURPOSE: Anemia is highly prevalent in the colorectal surgery population, affecting 30-70% of patients. Anemia is associated with significant morbidity and mortality; however, there is a lack of evidence on how much anemia impacts healthcare costs. This study aims to determine the hospital cost of index surgical admission, postoperative length of stay, and transfusion rate associated with preoperative anemia in elective major colorectal surgery. METHODS: This historical cohort study included 851 adult inpatients having elective colorectal surgery at a tertiary care academic health sciences network between April 2010 and February 2016. Anemia was defined as hematocrit ≤ 39%. The primary outcome was total hospital costs standardized to 2016 CAD. Secondary outcomes were postoperative length of stay and transfusion. Multivariable regression analyses and propensity score methods were used to measure adjusted associations between anemia and outcomes. RESULTS: Before surgery, 381/851 (45%) patients were anemic. The mean (standard deviation [SD]) cost of index admission for an elective colorectal surgery was 20,040 (23,219) CAD. Anemia was associated with an adjusted 14% relative increase in costs (95% confidence interval [CI], 6 to 23; P < 0.001). The total hospitalization cost attributable to anemia was 3,027 CAD (95% CI, 2,670 to 3,388). Hospital costs and length of stay were highly associated; anemia was associated with an 18% increase in length of stay (95% CI, 7 to 30; P < 0.001) and increased transfusion rates (risk ratio, 4.7; 95% CI, 2.71 to 8.33; P < 0.001). CONCLUSION: Over 2,600 CAD per index surgical admission is attributable to preoperative anemia. Preoperative interventions with per patient cost of less than 2,600 CAD could be cost effective at the hospital level. TRIAL REGISTRATION: www.clinicaltrials.gov (NCT03476707); registered 26 March, 2018.

RéSUMé: OBJECTIF: La prévalence de l'anémie est très élevée dans la population subissant une chirurgie colorectale, touchant 30­70 % des patients. L'anémie est associée à une morbidité et une mortalité importantes; toutefois, nous manquons de données probantes pour estimer les coûts des soins de santé associés à l'anémie. Cette étude avait pour but de déterminer les coûts hospitaliers de l'admission chirurgicale initiale, la durée de séjour postopératoire et le taux de transfusion associés à une anémie préopératoire lors de chirurgie colorectale majeure non urgente. MéTHODE: Cette étude de cohorte historique a inclus 851 patients adultes hospitalisés et subissant une chirurgie colorectale non urgente dans un réseau hospitalier universitaire de soins tertiaires entre avril 2010 et février 2016. L'anémie était définie comme un hématocrite ≤ 39 %. Le critère d'évaluation principal était les coûts hospitaliers totaux standardisés à la valeur du dollar canadien en 2016. Les critères d'évaluation secondaires étaient la durée de séjour postopératoire et les transfusions. Des analyses de régression multivariée et des évaluations par score de propension ont été utilisées pour mesurer les associations ajustées entre l'anémie et nos critères d'évaluation. RéSULTATS: Avant la chirurgie, 381/851 (45 %) patients étaient anémiques. Le coût moyen (écart type [ÉT]) de l'admission initiale pour une chirurgie colorectale non urgente était de 20 040 (23 219) CAD. L'anémie a été associée à une augmentation relative ajustée de 14 % des coûts (intervalle de confiance [IC] 95 %, 6 à 23; P < 0,001). Les coûts d'hospitalisation totaux attribuables à l'anémie étaient de 3027 CAD (IC 95 %, 2670 à 3388). Les coûts hospitaliers et la durée de séjour étaient très fortement associés; l'anémie a été associée à une augmentation de 18 % de la durée de séjour (IC 95 %, 7 à 30; P < 0,001) et des taux de transfusion (risque relatif, 4,7; IC 95 %, 2,71 à 8,33; P < 0,001). CONCLUSION: Plus de 2600 CAD pour l'admission chirurgicale initiale sont attribuables à l'anémie préopératoire. Des interventions préopératoires ayant un coût par patient de moins de 2600 CAD pourraient être rentables au niveau hospitalier. ENREGISTREMENT DE L'éTUDE: www.clinicaltrials.gov (NCT03476707); enregistrée le 26 mars 2018.

Protocol for the derivation and external validation of a 30-day mortality risk prediction model for older patients having emergency general surgery (PAUSE score-Probability of mortality Associated with Urgent/emergent general Surgery in oldEr patients score).

INTRODUCTION: People 65 years and older represent the fastest growing segment of the surgical population. Older age is associated with doubling of risk when undergoing emergency general surgery (EGS) procedures and often coexists with medical complexity and considerations of end-of-life care, creating prognostic and decisional uncertainty. Combined with the time-sensitive nature of EGS, it is challenging to gauge perioperative risk and ensure that clinical decisions are aligned with the patient values. Current preoperative risk prediction models for older EGS patients have major limitations regarding derivation and validation, and do not address the specific risk profile of older patients. Accurate and externally validated models specific to older patients are needed to inform care and decision making. METHODS AND ANALYSIS: We will derive, internally and externally validate a multivariable model to predict 30-day mortality in EGS patients >65 years old. Our derivation sample will be individuals enrolled in the National Surgical Quality Improvement Program (NSQIP) database between 2012 and 2016 having 1 of 7 core EGS procedures. Postulated predictor variables have been identified based on previous research, clinical and epidemiological knowledge. Our model will be derived using logistic regression penalised with elastic net regularisation and ensembled using bootstrap aggregation. The resulting model will be internally validated using k-fold cross-validation and bootstrap validation techniques and externally validated using population-based health administrative data. Discrimination and calibration will be reported at each step. ETHICS AND DISSEMINATION: Ethics for NSQIP data use was obtained from the Ottawa Hospital Research Ethics Board; external validation will use routinely collected anonymised data legally exempt from research ethics review. The final risk score will be published in a peer-reviewed journal. We plan to further disseminate the model as an online calculator or application for clinical use. Future research will be required to test the clinical application of the final model.