Patient selection for routine troponin monitoring after noncardiac surgery

BACKGROUND: Myocardial infarction is an important complication after noncardiac surgery. Therefore, perioperative troponin surveillance is recommended for patients at risk. The aim of this study was to identify patients at high risk of perioperative myocardial infarction (POMI), in order to aid appropriate selection and to omit redundant laboratory measurements in patients at low risk. METHODS AND RESULTS: This observational cohort study included patients ≥60 years of age who underwent intermediate to high risk noncardiac surgery. Routine postoperative troponin I monitoring was performed. The primary outcome was POMI. Classification and regression tree analysis was used to identify patient groups with varying risks of POMI. In each subgroup, the number needed to screen to identify 1 patient with POMI was calculated. POMI occurred in 216 (4%) patients and other myocardial injury in 842 (15%) of the 5590 included patients. Classification and regression tree analysis divided patients into 14 subgroups in which the risk of POMI ranged from 1.7% to 42%. Using a risk of POMI ≥2% to select patients for routine troponin I monitoring, this monitoring would be advocated in patients ≥60 years of age undergoing emergency surgery, or those undergoing elective surgery with a Revised Cardiac Risk Index class >2 (ie >1 risk factor). The number needed to screen to detect a patient with POMI would be 14 (95% CI 14–14) and 26% of patients with POMI would be missed. CONCLUSIONS: To improve selection of high-risk patients ≥60 years of age, routine postoperative troponin I monitoring could be considered in patients undergoing emergency surgery, or in patients undergoing elective surgery classified as having a revised cardiac risk index class >2

Added value of subjective assessed functional capacity before non-cardiac surgery in predicting postoperative myocardial injury

Background: Functional capacity is used as an indicator for cardiac testing before non-cardiac surgery and is often performed subjectively. However, the value of subjectively estimated functional capacity in predicting cardiac complications is under debate. We determined the predictive value of subjectively assessed functional capacity on postoperative cardiac complications and mortality. Design: An observational cohort study in patients aged 60 years and over undergoing elective inpatient non-cardiac surgery in a tertiary referral hospital. Methods: Subjective functional capacity was determined by anaesthesiologists. The primary outcome was postoperative myocardial injury. Secondary outcomes were postoperative inhospital myocardial infarction and one year mortality. Logistic regression analysis and area under the receiver operating curves were used to determine the added value of functional capacity. Results: A total of 4879 patients was included; 824 (17%) patients had a poor subjective functional capacity. Postoperative myocardial injury occurred in 718 patients (15%). Poor functional capacity was associated with myocardial injury (relative risk (RR) 1.7, 95% confidence interval (CI) 1.5–2.0; P < 0.001), postoperative myocardial infarction (RR 2.9, 95% CI 1.9–4.2; P < 0.001) and one year mortality (RR 1.7, 95% CI 1.4–2.0; P < 0.001). After adjustment for other predictors, functional capacity was still a significant predictor for myocardial injury (odds ratio (OR) 1.3, 95% CI 1.0–1.7; P = 0.023), postoperative myocardial infarction (OR 2.0, 95% CI 1.3–3.0; P = 0.002) and one year mortality (OR 1.4, 95% CI 1.1–1.8; P = 0.003), but had no added value on top of other predictors. Conclusions: Subjectively assessed functional capacity is a predictor of postoperative myocardial injury and death, but had no added value on top of other preoperative predictors

Accounting for Breakout in Britain: The Industrial Revolution Through a Malthusian Lens

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

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; β: 3.3, 95% confidence interval [CI]: 0.5–6.2), but scores remained stable after surgery (β: 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 (β: 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 (β: 11.2, 95% CI: 2.3–20.2; β: 8.1, 95% CI: 3.0–13.2, respectively). Patients with clinically silent PMI did not change in disability score at 6 months (β: 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

Flexible mechanoprosthesis made from woven ultra-high-molecular-weight polyethylene fibres : proof of concept in a chronic sheep model

OBJECTIVES: Ultra-high-molecular-weight polyethylene (UHMWPE) fibres are flexible, have high tensile strength, and platelet and bacterial adhesion is low. Therefore, UHMWPE may overcome limitations of current mechanical valves and bioprostheses. In this study, the biocompatibility and functionality of prototype handmade stented valves from woven UHMWPE (U-valve) was assessed in a chronic sheep model with acetylsalicylic acid monotherapy. METHODS: Native pulmonary valves of 23 sheep were replaced by U-valves (n = 18) or Perimount bovine bioprostheses (reference group, n = 5). Sheep received 80 mg of acetylsalicylic acid daily. Follow-up was conducted at 1 week (n = 4), 1 month (n = 5), 3 months (n = 5) and 6 months (n = 4) in the U-valve group and at 3 months (n = 2) and 6 months (n = 3) in the reference group. Epicardial echocardiography and histology were used to assess valve function and tissue deposition, respectively. RESULTS: Seventeen U-valve sheep (94%) and 3 reference sheep (60%) survived the perioperative period. One reference valve sheep was sacrificed after 4 months because of congestive heart failure. At explantation, all U-valves were intact without leaflet tearing. Up to 3 months, U-valves were flexible and free of stenosis. Regurgitation was mostly mild though gradually increasing; histology showed minimal connective tissue near the leaflet base and sparse calcification. At 6 months, connective tissue was diffusely observed on the leaflets with retraction and consecutive regurgitation and leaflet thickening. CONCLUSIONS: Valves made from UHMWPE fibres demonstrated early feasibility in the pulmonary valve position with reasonably good haemodynamics and intact valve materials up to 6 months. Gradual leaflet thickening and retraction were observed after 3 months due to connective tissue overgrowth

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; β: 3.3, 95% confidence interval [CI]: 0.5–6.2), but scores remained stable after surgery (β: 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 (β: 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 (β: 11.2, 95% CI: 2.3–20.2; β: 8.1, 95% CI: 3.0–13.2, respectively). Patients with clinically silent PMI did not change in disability score at 6 months (β: 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.</p