Postoperative Troponin Research Articles

IP235. Transfusion Timing and Postoperative Myocardial Infarction and Death in Patients Undergoing Common Vascular Procedures

Perioperative blood transfusion, specifically of packed red blood cells (pRBCs), after vascular surgery procedures is one modifiable risk factor that is associated with increased cardiovascular events and 30-day mortality. The aim of this study was to evaluate the effect of transfusion timing (intraoperative vs postoperative) on the rate of postoperative myocardial infarction (POMI) and death. Seven surgical and endovascular modules within the Vascular Quality Initiative from 2013 to 2017 were reviewed at a single institution. Transfusion data on elective and urgent cases were abstracted, and all inpatients underwent routine postoperative troponin and electrocardiography testing. The primary end point was POMI using the universal definition of MI. The secondary end point was 30-day mortality. Multivariable logistic regression analysis was used to evaluate the risk of transfusions on POMI and death. We identified 1154 cases for analysis (299 endovascular aneurysm repairs; 117 infrainguinal bypasses; 127 open abdominal aortic aneurysm repairs; 41 suprainguinal bypasses; 168 thoracic endovascular aortic repairs; and 402 peripheral vascular interventions, of which 90 had femoral endarterectomy). Overall, the POMI rate was 2% and mortality 1.4%. POMI and death rates did not differ by type of procedure (P = .053 for MI and P = .423 for mortality). The mean number of intraoperative pRBC and postoperative pRBC transfusions was higher for patients with POMI (intraoperative, 0.3 vs 1.3; postoperative, 0.4 vs 1.8; both P < .01) and death (intraoperative, 0.3 vs 1.4; postoperative, 0.4 vs 2.5; both P < .01). In addition, age and coronary artery disease was associated with MI on univariable analysis. On multivariable analysis for POMI, coronary artery disease (odds ratio [OR], 5.42; 95% confidence interval [CI], 2.09-14.06; P < .001) and postoperative transfusion (OR, 4.9; 95% CI, 1.92-12.49; P < .001) were both significant; however, intraoperative transfusion was not (OR, 1.37; 95% CI, 0.49-3.83; P = .55). On multivariable analysis, postoperative death was associated with increasing age of the patient (OR, 1.08; 95% CI, 1.01-1.15; P = .017), and statin use was highly protective (OR, 0.26; 95% CI, 0.095-0.74; P = .012), but intraoperative or postoperative transfusion was not associated with death after adjustment. In our series with routine postoperative troponin screening, the use of postoperative but not intraoperative pRBC transfusion was associated with POMI. We did not identify an association of transfusion with postoperative death. These data suggest that the perioperative setting of transfusions is important in its impact on postoperative outcomes and needs to be accounted for in evaluating transfusion outcomes and indications.

Improvement of mitochondrial function in human atrial tissue by remote ischemic conditioning

IntroductionRemote ischemic preconditioning (RIPC), repeated cycles of brief limb ischemia/reperfusion, attenuates postoperative troponin release in patients undergoing surgical coronary revascularization and improves clinical outcome in some, but not all studies. Mitochondria are the end‐effectors of cardioprotection by local ischemic conditioning maneuvers in experimental studies. Here, we now analyzed mitochondrial function in response to RIPC in human atrial tissue.MethodsPatients undergoing elective surgical coronary revascularization under isoflurane anesthesia were randomized to RIPC by 3× 5 min/5 min upper arm blood pressure cuff inflation/deflation or placebo (n=30/30), and their right atrial appendages were harvested prior to ischemic cardioplegic arrest. Cardioprotection was reflected by a 14% decrease with RIPC vs. placebo in the area under the curve of serum troponin I/T concentrations over 72 h after surgery. Mitochondria were isolated from the atrial tissue (n=10/10). Mitochondrial function, i.e. mitochondrial respiration, adenosine triphosphate (ATP) production, reactive oxygen species (ROS) production and calcium retention capacity (CRC) to estimate mitochondrial permeability transition pore (mPTP) opening, was measured at physiological temperature of 37°C. Data are given as mean±SEM.ResultsAssociated with the observed cardioprotection in patients, mitochondrial function was improved by RIPC. Basal respiration was not different between RIPC and placebo. ADP‐stimulated complex I respiration was significantly greater with RIPC than with placebo. Mitochondrial complex IV respiration and maximal oxygen uptake of uncoupled mitochondria were not different between RIPC and placebo, reflecting an equal loading of viable mitochondria (Figure 1A). The mitochondrial ATP production (Figure 1B) was greater whereas mitochondrial ROS production (Figure 1C) was less with RIPC than with placebo. CRC of mitochondria (Figure 1D) was improved with RIPC in comparison to placebo, with and without cyclosporine A.ConclusionIn human myocardium, mitochondria are an intracellular target of protection by RIPC.Support or Funding InformationSupported by: German Research Foundation (SFB 1116 B8)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Myocardial Protection by Glucose-Insulin-Potassium in Moderate- to High-Risk Patients Undergoing Elective On-Pump Cardiac Surgery: A Randomized Controlled Trial.

Low cardiac output syndrome is a main cause of death after cardiac surgery. We sought to assess the impact of glucose-insulin-potassium (GIK) to enhance myocardial protection in moderate- to high-risk patients undergoing on-pump heart surgery. A randomized controlled trial was performed in adult patients (Bernstein-Parsonnet score >7) scheduled for elective aortic valve replacement and/or coronary artery bypass surgery. Patients were randomized to GIK (20 IU of insulin, 10 mEq of potassium chloride in 50 mL of glucose 40%) or saline infusion given over 60 minutes on anesthetic induction. The primary end point was postcardiotomy ventricular dysfunction (PCVD), defined as new/worsening left ventricular dysfunction requiring inotropic support (≥120 minutes). Secondary end points were the intraoperative changes in left ventricular function as assessed by transoesophageal echocardiography, postoperative troponin levels, cardiovascular and respiratory complications, and intensive care unit and hospital length of stay. From 224 randomized patients, 222 were analyzed (112 and 110 in the placebo and GIK groups, respectively). GIK pretreatment was associated with a reduced occurrence of PCVD (risk ratio [RR], 0.41; 95% confidence interval [CI], 0.25-0.66). In GIK-treated patients, the left systolic ventricular function was better preserved after weaning from bypass, plasma troponin levels were lower on the first postoperative day (2.9 ng·mL(-) [interquartile range {IQR}, 1.5-6.6] vs 4.3 ng·mL(-) [IQR, 2.4-8.2]), and cardiovascular (RR, 0.69; 95% CI, 0.50-0.89) and respiratory complications (RR, 0.5; 95% CI, 0.38-0.74) were reduced, along with a shorter length of stay in intensive care unit (3 days [IQR, 2-4] vs 3.5 days [IQR, 2-7]) and in hospital (14 days [IQR, 11-18.5] vs 16 days [IQR, 12.5-23.5]), compared with placebo-treated patients. GIK pretreatment was shown to attenuate PCVD and to improve clinical outcome in moderate- to high-risk patients undergoing on-pump cardiac surgery.

Myocardial injury after non-cardiac surgery: a perioperative affair?

Myocardial injury after non-cardiac surgery (MINS) is a rather new nosological entity and an unfortunately common perioperative complication. The diagnostic criteria for MINS, also indicated as isolated myocardial injury (IMI), are an elevated postoperative high sensitivity troponin T (hsTnT level ranging between 20 and 65 ng/L with an absolute change of at least 5 ng/L or hsTnT level >65 ng/L), in absence of symptoms and/or EKG findings suggestive of ischemia and without a non-ischemic etiology causing troponin elevation. MINS does not fulfill the universal definition of myocardial infarction even if it is related to ischemic causes and it is independently associated with 30-day postoperative mortality and complications. Nevertheless, mortality at 30 days in MINS patients has been calculated up to 10% and it increases exponentially as a function of peak postoperative troponin concentration. Physician and researchers should discriminate MINS from perioperative myocardial infarction and from not ischemic troponin increases. In the postoperative period, the possibility of missing the diagnosis of an acute coronary syndrome for the paucity of clinical symptoms or because physician failed to evaluate a postoperative EKG recording should always be considered. Physiopathology of MINS is not yet well defined: current hypotheses are surrogated from perioperative myocardial infarction studies. Up to now there are not specific treatments for MINS, even if antithrombotic therapy is under evaluation. Treatment decisions should be tailored to the individual case; potential benefits of troponin screening include a cardiology consultation and consequently, improved patients' information to promote lifestyle changes and enhanced therapy.

Prognostic Value of Early Postoperative Troponin T in Patients Undergoing Coronary Artery Bypass Grafting.

BackgroundCardiac troponin T (cTnT) is elevated after coronary artery bypass grafting surgery. The aim of this study was to determine the association between cTnT elevations between 6 and 12 hours after coronary artery bypass grafting and in‐hospital outcome.Methods and ResultsWe prospectively studied 1722 patients undergoing isolated coronary artery bypass grafting. We assessed the association between conventional cTnT (749 patients) and high‐sensitivity cTnT (hs‐cTnT; 973 patients) 6 to 12 hours postoperatively with in‐hospital major adverse cardiac or cerebrovascular events (MACCE), a composite of all‐cause death, myocardial infarction, or stroke. The prespecified secondary outcome was a safety composite of MACCE, resuscitation, intensive care unit readmission or admission ≥48 hours, inotrope or vasopressor use ≥24 hours, or new‐onset renal insufficiency. Among patients with a conventional cTnT measurement, 92 experienced a MACCE (12%) and 146 experienced a safety composite event (19%). Likewise, for hs‐cTnT, 114 experienced a MACCE (12%) and 153 experienced a safety composite event (16%). Compared with cTnT ≤200 ng/L, each 200‐ng/L increment in cTnT was associated with a monotonous increase in the odds of MACCE and the safety composite outcome. Conventional and hs‐cTnT demonstrated moderate discrimination for MACCE (areas under the fitted receiver operating characteristics curve, 0.72 and 0.77 for conventional and hs‐cTnT, respectively) and the safety composite outcome (areas under the fitted receiver operating characteristics curve, 0.66 and 0.74 for conventional and hs‐cTnT, respectively) and resulted in improved prognostic performance when added to the EuroSCORE. At a cutoff of 800 ng/L, conventional and hs‐cTnT provided clinically relevant power to rule in MACCE and the safety composite outcome.Conclusions cTnT levels assessed between 6 and 12 hours after coronary artery bypass grafting identify patients at increased risk of MACCE or other complications.

Del Nido cardioplegia in adult cardiac surgery: beyond single-valve surgery.

In recent years, the use of del Nido (DN) cardioplegia has been reported in single-valve surgery or isolated coronary artery bypass surgery with acceptable outcomes. The reports of its use in more complex adult cardiac procedures, however, have been scarce. We enrolled a total of 149 adult patients who underwent heart valve surgery with the use of DN cardioplegia between May 2014 and December 2016. For a benchmark comparison, 892 patients who underwent cardiac valve surgery with blood cardioplegia during the same period served as controls. To reduce selection bias, propensity score matching was used; the inverse probability of treatment weighting method was performed for further validations. Overall, 57.7% of patients in the DN group underwent multiple or complex cardiac procedures. Early mortality rates were 0.7% and 2.4% in the DN and blood groups, respectively (P = 0.31). Propensity score matching yielded 111 pairs of patients who were well balanced for all 23 measured baseline covariates. In the matched cohort, the postoperative peak troponin I levels (P = 0.004) and the aortic clamping times (P < 0.001) were significantly lower and shorter compared with those in the blood group. There were no significant differences in early mortality rates (1.9% vs 0%, P > 0.99), low cardiac output (P = 0.57) and neurological events (P = 0.21). The quantities of postoperative transfusions (P = 0.008) and fluid supplements (P < 0.001) were significantly lower in the matched DN group compared with the blood group. The use of DN in adult valve surgery including complex procedures may confer acceptable outcomes comparable to or even superior to those obtained with the use of blood cardioplegia.

Establishment of an easy and straight forward heparinase protocol to analyse circulating and myocardial tissue micro-RNA during coronary artery-bypass-graft surgery

Coronary artery-bypass-graft (CABG) surgery is associated with myocardial damage and increased blood concentrations of circulating microRNAs (miRNA). However, whether and to what extent these miRNAs relate to cardiac tissue miRNA expression have not yet been explored. Since plasma miRNA quantification in samples from cardiopulmonary bypass (CPB) patients is severely hampered by heparin, we established and validated successfully a protocol to reliably measure miRNA in 49 heparinized patients undergoing CABG so as to investigate the relationship between circulating and right atrial miRNAs. Plasma and right atrial expression of miR-1, miR-133a, miR-423-5p, and miR-499 were measured before and after CPB, as well as miRNAs in plasma 24 h thereafter. All plasma miRNAs increased significantly with surgery while cardiac tissue expression of only miR-133a (1.4-fold; p = 0.003) and miR-423-5p (1.3 fold; p = 0.025) increased as well. Right atrial and plasma miR-133a expression correlated positively before CPB (r = 0.288, p = 0.045) but miR-499 expression inversely (r = −0.484, p = 0.0004). There was a strong association between plasma miR-133a and miR-499 concentrations and postoperative troponin I concentrations, the marker for myocardial damage. Increased myocardial miR-133a and miR-423-5p expression together with unchanged miR-1 and miR-499 expression might suggest active release of these miRNAs rather than their origin from damaged cells.

Prognostic value of postoperative high-sensitivity troponin T in patients with different stages of kidney disease undergoing noncardiac surgery

BackgroundEmerging evidence suggests that postoperative troponin release is a strong and independent predictor of short-term mortality. However, evaluating elevated troponins in patients with chronic kidney disease (CKD) is still controversial and is often disregarded. This study examines morbidity along with short- and long-term mortality risk associated with elevated high-sensitivity troponin T (hsTnT) in patients with different stages CKD undergoing noncardiac surgery. MethodsThis observational cohort comprised 3262 patients aged ≥60 yr who underwent noncardiac surgery. Postoperative hsTnT concentrations were divided into normal [<14 ng l−1 (reference)], low (14–49 ng l−1), moderate (50–149 ng l−1), and high (≥150 ng l−1) groups. A threshold of 50 ng l−1 was used to dichotomize hsTnT. The study endpoints were 30-day and long-term all-cause mortality, and postoperative myocardial infarction. ResultsPostoperative hsTnT was associated with a stepwise increase in 30-day and long-term mortality risk: low hsTnT adjusted hazard ratio (HR) 1.4 [95% confidence interval (CI): 1.1–1.7], moderate hsTnT adjusted HR 3.1 (95% CI: 2.3–4.3), high hsTnT adjusted HR 5.5 (95% CI: 3.6–8.4). Postoperative hsTnT ≥50 ng l−1 was associated with 30-day and long-term mortality risk for each stage of CKD. Elevated troponin concentrations in severe CKD (estimated glomerular filtration rate <30 mL min−1 1.73 m−2), however, did not predict short-term death. ConclusionsElevated postoperative hsTnT is associated with a dose-dependent increase in 30-day and long-term mortality risk in each stage of CKD with an estimated glomerular filtration rate ≥30 ml min−1 1.73 m−2.

Postoperative troponin measurement as a screening tool for adverse cardiac events in adult patients undergoing moderate or major non-cardiac surgery.

Elevated troponin levels within three days of surgery are strongly linked to major adverse cardiac events (MACE). However, the value of screening with troponin measurements is controversial. The extent to which this is done in routine practice is uncertain. We examined the medical records of all patients ≥45 years of age undergoing moderate or major non-cardiac surgery in our tertiary referral hospital over a six-month period. We determined how many patients had a troponin (TnT) measurement recorded in the first three days postoperatively, how many of these were abnormal, and the occurrence of MACE within 30 days. Two thousand and two hundred patients underwent 2,577 operations that met the study criteria. A postoperative TnT was measured after 4.5% of operations. Thirty-eight percent of patients with a recorded TnT measurement, and 44% of those with an abnormal measurement, experienced a MACE within 30 days. The sensitivity of an abnormal TnT to detect MACE was 86%. The specificity was low at 32% with a false positive rate of 56%. Patients with an abnormal TnT result had an increased risk of MACE (23%). The 'number needed to measure' to detect one patient with MACE was 4.4. In our institution, postoperative TnT levels were rarely measured and were used as a diagnostic rather than as a screening tool. The high false positive rate for MACE prediction limits its potential value as a screening tool. The test could be considered useful if it leads to further investigation, and may be best considered as one component of a multivariate approach to cardiac risk evaluation and diagnosis.

Sevoflurane-induced cardioprotection in coronary artery bypass graft surgery: Randomised trial with clinical and ex-vivo endpoints

BackgroundMyocardial ischaemia reperfusion injury following cardiac surgery with cardiopulmonary bypass (CPB) increases postoperative mortality. Setting techniques to protect the heart during this critical period therefore represents a considerable challenge. MethodA randomised controlled study in Caen University Hospital Centre, investigated whether the clinical cardio protective effects of administration sevoflurane before cardiopulmonary bypass during coronary artery bypass graft surgery (CABG) could translate into protected atrial trabeculae contractility against hypoxia–reoxygenation in vitro. Patients undergoing elective on-pump CABG surgery were allocated to receive either sevoflurane (n=24) or no halogenated volatile anaesthetic (n=21). Main outcome measures: the relationship between sevoflurane exposure before CPB and the incidence of major adverse cardiac events, with primary endpoint: the postoperative troponin I peak level, and secondary endpoints: the inotropic support, and the duration of stay in intensive unit and in-hospital stay were chosen as study endpoints. The right atrial was collected at the beginning of bypass surgery for the in vitro experimentation. Isometrically contracting isolated human right atrial trabeculae obtained from the two groups were exposed to 30-min hypoxia followed by 60-min reoxygenation. ResultsThe patients receiving sevoflurane prior to aortic clamping significantly exhibited less cardiac Troponin I (1.39 [0.34–2.97] vs. 2.80 [2.54–3.64] ng·mL−1 in Control; P=0.03) and required a reduced inotropic drug support (P<0.001). Isolated trabeculae from patients receiving sevoflurane enhanced the recovery of force after reoxygenation compared to the Control group (79±5% vs. 53±8% of baseline in Control; P<0.001). ConclusionsAdministration of sevoflurane before CPB induced cardioprotection in patients undergoing CABG and preconditioned human myocardium against hypoxia-reoxygenation in vitro.

Association of Troponin Trends and Cardiac Morbidity and Mortality After On-Pump Cardiac Surgery

Elevated, single-measure, postoperative troponin is associated with adverse events after cardiac surgery. We hypothesized that increases in troponin from the first to the second postoperative day are also associated with all-cause, 12-month mortality and major adverse cardiac events (MACE). This observational study included consecutive adults undergoing on-pump cardiac surgery with cardiac arrest. Troponin T was measured on the first andsecond postoperative day and was classified as "increasing" (>10%), "unchanged" (10% to -10%), or "decreasing" (<-10%). The primary endpoint was all-cause, 12-month mortality. Secondary endpoints were all-cause 12-month mortality or MACE and both outcomes at 30 days. Themain analysis was by multivariable Cox regression. Of 1,417 included patients, 99 (7.0%) died and 162 (11.4%) died or suffered MACE at 12 months. A significant interaction (p < 0.001) between first postoperative day troponin and the troponin trend from the first to the second postoperative day on 12-month, all-cause mortality precluded an analysis independent of first postoperative day troponin. Consequently, we stratified patients by their first postoperative day troponin (cutoff, 0.8 μg/L). Increasing troponin was associated with higher mortality in patients with first postoperative day troponin T ≥ 0.8 μg/L (hazard ratio, 1.98; 95% CI, 1.09 to 3.59; p=0.025). Troponin changes from the first to the second postoperative day should not be interpreted without consideration of the first postoperative day troponin concentration. For patients with a first postoperative day troponin ≥ 0.8 μg/L, an increase by more than 10% from the first to the second postoperative day was significantly associated with all-cause, 12-month mortality and other adverse events.

GNAQ TT(-695/-694)GC Polymorphism Is Associated with Increased Gq Expression, Vascular Reactivity, and Myocardial Injury after Coronary Artery Bypass Surgery.

Angiotensin II receptor type 1-mediated activation of the α-subunit of the heterotrimeric Gq protein evokes increased vasoconstriction and may promote hypertrophy-induced myocardial damage. The authors recently identified a TT(-695/-694)GC polymorphism in the human Gq promoter, the GC allele being associated with an increased prevalence of cardiac hypertrophy. In this article, the authors tested whether the TT(-695/-694)GC polymorphism is associated with differences in (1) myocardial Gq protein expression, (2) vascular reactivity, and (3) myocardial damage after coronary artery bypass grafting. Gq protein expression was measured in right atrial muscle from 55 patients undergoing coronary artery bypass grafting as were skin perfusion changes (n = 18; laser Doppler imaging), saphenous vein ring vascular reactivity (n = 50, organ bath) in response to angiotensin II, and myocardial damage (227 patients undergoing coronary artery bypass grafting), as assessed by postoperative cardiac troponin I concentration. Myocardial Gq expression was greater in GC/GC genotypes (GC/GC vs. 1.27-fold change; P = 0.006). Skin perfusion after intradermal angiotensin II injection decreased only in GC/GC genotypes (P = 0.0002). Saphenous vein rings exposed to increasing angiotensin II concentrations showed an almost doubled maximum contraction in GC/GC compared with individuals with the TT/TT genotype (P = 0.022). In patients undergoing coronary artery bypass grafting, baseline cardiac ejection fraction was different (GC/GC: 55 ± 13%; GC/TT: 54 ± 14%; TT/TT: 48 ± 15%; P = 0.037) and postoperative peak cardiac troponin I was greater in patients with the GC/GC (11.5 ± 13.8 ng/ml) than in patients with the GC/TT (9.2 ± 9.2 ng/ml) or patients with the TT/TT genotype (6.6 ± 4.8 ng/ml, P = 0.015). The GC/GC genotype of the TT(-695/-694)GC polymorphism is associated with increased Gq protein expression, augmented angiotensin II receptor type 1-related vasoconstriction, and increased myocardial injury after coronary artery bypass grafting, highlighting the impact of Gq genotype variation.

Myocardial Injury After Noncardiac Surgery (MINS) in Vascular Surgical Patients: A Prospective Observational Cohort Study.

To determine the prognostic relevance, clinical characteristics, and 30-day outcomes associated with myocardial injury after noncardiac surgery (MINS) in vascular surgical patients. MINS has been independently associated with 30-day mortality after noncardiac surgery. The characteristics and prognostic importance of MINS in vascular surgery patients are poorly described. This was an international prospective cohort study of 15,102 noncardiac surgery patients 45 years or older, of whom 502 patients underwent vascular surgery. All patients had fourth-generation plasma troponin T (TnT) concentrations measured during the first 3 postoperative days. MINS was defined as a TnT of 0.03 ng/mL of higher secondary to ischemia. The objectives of the present study were to determine (i) if MINS is prognostically important in vascular surgical patients, (ii) the clinical characteristics of vascular surgery patients with and without MINS, (iii) the 30-day outcomes for vascular surgery patients with and without MINS, and (iv) the proportion of MINS that probably would have gone undetected without routine troponin monitoring. The incidence of MINS in the vascular surgery patients was 19.1% (95% confidence interval (CI), 15.7%-22.6%). 30-day all-cause mortality in the vascular cohort was 12.5% (95% CI 7.3%-20.6%) in patients with MINS compared with 1.5% (95% CI 0.7%-3.2%) in patients without MINS (P < 0.001). MINS was independently associated with 30-day mortality in vascular patients (odds ratio, 9.48; 95% CI, 3.46-25.96). The 30-day mortality was similar in MINS patients with (15.0%; 95% CI, 7.1-29.1) and without an ischemic feature (12.2%; 95% CI, 5.3-25.5, P = 0.76). The proportion of vascular surgery patients who suffered MINS without overt evidence of myocardial ischemia was 74.1% (95% CI, 63.6-82.4). Approximately 1 in 5 patients experienced MINS after vascular surgery. MINS was independently associated with 30-day mortality. The majority of patients with MINS were asymptomatic and would have gone undetected without routine postoperative troponin measurement.

Altered preoperative coagulation and fibrinolysis are associated with myocardial injury after non-cardiac surgery

BackgroundMyocardial injury after non-cardiac surgery (MINS), a complication with unclear pathogenesis, occurs within the first 30 days after surgery and worsens prognosis. Hypercoagulability induced by surgery might contribute to plaque rupture, with subsequent thrombosis and myocardial injury. This study assessed haemostatic markers before surgery and evaluated their association with MINS. MethodsThis is a substudy of VISION, a prospective cohort study of perioperative cardiovascular events. Of 475 consecutive vascular surgery patients, 47 (9.9%) developed MINS, defined as postoperative high-sensitivity troponin ≥50 ng litre−1, with ≥20% elevation from the preoperative concentration. The control group consisted of 84 non-MINS patients matched for patient characteristics and co-morbidities. The following preoperative markers of hypercoagulability and fibrinolysis were measured: antithrombin, factor VIII activity, von Willebrand factor concentration and activity, fibrinogen, D-dimer, plasmin–antiplasmin complex, and tissue plasminogen activator. Moreover, C-reactive protein and CD40L concentrations were measured to assess inflammatory activity. ResultsPatients with MINS compared with the non-MINS group had a significantly higher concentration of factor VIII (186 vs 155%, P=0.006), von Willebrand factor activity (223 vs 160%, P<0.001), von Willebrand factor concentration (317 vs 237%, P=0.02), concentrations of fibrinogen (5.6 vs 4.2 g litre−1, P=0.03), D-dimer (1680.0 vs 1090.0 ng ml−1, P=0.04), plasmin–antiplasmin complex (747 vs 512 ng ml−1, P=0.002) and C-reactive protein (10 vs 4.5 mg litre−1, P=0.02) but not antithrombin (95 vs 94%, P=0.89), tissue plasminogen activator (11 vs 9.7 ng ml−1, P=0.06) and CD40L (8790 vs 8580 pg ml−1, P=0.73). ConclusionsPreoperative elevation of blood markers of hypercoagulability in patients undergoing vascular surgery is associated with a higher risk of MINS. Clinical trial registrationNCT00512109.

Association of Postoperative High-Sensitivity Troponin Levels With Myocardial Injury and 30-Day Mortality Among Patients Undergoing Noncardiac Surgery

Little is known about the relationship between perioperative high-sensitivity troponin T (hsTnT) measurements and 30-day mortality and myocardial injury after noncardiac surgery (MINS). To determine the association between perioperative hsTnT measurements and 30-day mortality and potential diagnostic criteria for MINS (ie, myocardial injury due to ischemia associated with 30-day mortality). Prospective cohort study of patients aged 45 years or older who underwent inpatient noncardiac surgery and had a postoperative hsTnT measurement. Starting in October 2008, participants were recruited at 23 centers in 13 countries; follow-up finished in December 2013. Patients had hsTnT measurements 6 to 12 hours after surgery and daily for 3 days; 40.4% had a preoperative hsTnT measurement. A modified Mazumdar approach (an iterative process) was used to determine if there were hsTnT thresholds associated with risk of death and had an adjusted hazard ratio (HR) of 3.0 or higher and a risk of 30-day mortality of 3% or higher. To determine potential diagnostic criteria for MINS, regression analyses ascertained if postoperative hsTnT elevations required an ischemic feature (eg, ischemic symptom or electrocardiography finding) to be associated with 30-day mortality. Among 21 842 participants, the mean age was 63.1 (SD, 10.7) years and 49.1% were female. Death within 30 days after surgery occurred in 266 patients (1.2%; 95% CI, 1.1%-1.4%). Multivariable analysis demonstrated that compared with the reference group (peak hsTnT <5 ng/L), peak postoperative hsTnT levels of 20 to less than 65 ng/L, 65 to less than 1000 ng/L, and 1000 ng/L or higher had 30-day mortality rates of 3.0% (123/4049; 95% CI, 2.6%-3.6%), 9.1% (102/1118; 95% CI, 7.6%-11.0%), and 29.6% (16/54; 95% CI, 19.1%-42.8%), with corresponding adjusted HRs of 23.63 (95% CI, 10.32-54.09), 70.34 (95% CI, 30.60-161.71), and 227.01 (95% CI, 87.35-589.92), respectively. An absolute hsTnT change of 5 ng/L or higher was associated with an increased risk of 30-day mortality (adjusted HR, 4.69; 95% CI, 3.52-6.25). An elevated postoperative hsTnT (ie, 20 to <65 ng/L with an absolute change ≥5 ng/L or hsTnT ≥65 ng/L) without an ischemic feature was associated with 30-day mortality (adjusted HR, 3.20; 95% CI, 2.37-4.32). Among the 3904 patients (17.9%; 95% CI, 17.4%-18.4%) with MINS, 3633 (93.1%; 95% CI, 92.2%-93.8%) did not experience an ischemic symptom. Among patients undergoing noncardiac surgery, peak postoperative hsTnT during the first 3 days after surgery was significantly associated with 30-day mortality. Elevated postoperative hsTnT without an ischemic feature was also associated with 30-day mortality.

Volatile anaesthetics added to cardiopulmonary bypass are associated with reduced cardiac troponin.

Every year, over 1 million cardiac surgical procedures are performed all over the world. Reducing myocardial necrosis could have strong implications in postoperative clinical outcomes. Volatile anaesthetics have cardiac protective properties in the perioperative period of cardiac surgery. However, little data exists on the administration of volatile agents during cardiopulmonary bypass. The aim of this study was to assess if volatile anaesthetics administration during cardiopulmonary bypass reduces cardiac troponin release after cardiac surgery. We retrospectively analysed data from 942 patients who underwent cardiac surgery in a teaching hospital. The only difference between the groups was the management of anaesthesia during CPB. The volatile group received sevoflurane or desflurane while the control group received a combination of propofol infusion and fentanyl boluses. Patients who received volatile anaesthetics during cardiopulmonary bypass (n=314) were propensity-matched 1:2 with patients who did not receive volatile anaesthetics during CPB (n=628). We found a reduction in peak postoperative troponin I, from 7.8 ng/ml (4.8-13.1) in the non-volatile group to 6.8 ng/ml (3.7-11.8) in the volatile group (p=0.013), with no differences in mortality [2 (0.6%) in the volatile group and 2 (0.3%) in the non-volatile group (p=0.6)]. Adding volatile anaesthetics during cardiopulmonary bypass was associated with reduced peak postoperative troponin levels. Larger studies are required to confirm our data and to assess the effect of volatile agents on survival.

Prognostic value of the new high sensitive cardiac troponin T assay (hs-cTnT) after coronary artery bypass grafting

Background The aim of the study was to assess the value of post-operative cardiac troponin T-levels, measured with a new highly sensitive assay (hs-cTnT), as a suitable parameter to predict patients’ outcome after cardiac surgery. With the introduction of the new hs-cTnT assay the correlation between measured levels and the post-operative patient’s outcome remains to be evaluated.Methods Patients undergoing coronary artery bypass grafting (n = 213) were included. Perioperative measurements of hs-cTnT and CK-MB were correlated to parameters of clinical outcome and further explored. Patients with an uneventful course were compared with those with post-operative complications, including need of repeat revascularization (RR) or death (RR/death), cardiogenic shock (CS) or death (CS/death) and a combination of all (RR/CS/death).Results Significant results were observed in patients after isolated CABG, where CS/death and RR/CS/death patients had higher post-operative hs-cTnT levels (P < 0.01). Moreover, multivariate analysis of the CABG-group revealed that acute renal failure (OR =14.7, 95% CI =2.7-79.1, P < 0.001), early post-operative hs-cTnT levels higher than the upper quintile (> 1,476.8 pg/ml) (OR =8.1, 95% CI =3.0-22.2, P < 0.001) and unstable angina pectoris (OR =2.4, 95% CI =1.1-5.7, P < 0.05) were the most powerful independent predictors of post-operative complications. Upon discriminant analysis the application of hs-cTnT almost doubled the sensitivity of the outcome prediction.Conclusions The new hs-cTnT assay is a useful diagnostic tool that may significantly enhance the prediction of adverse events after CABG. In our study a hs-cTnT-value >1,476.8 pg/ml proved to be a reliable marker for ongoing post-operative complications.

Myocardial protection during minimally invasive cardiac surgery through right mini-thoracotomy.

Myocardial damage is an independent predictor of adverse outcome following cardiac surgery and myocardial protection is one of the key factors to achieve successful outcomes. Cardioplegia with Custodiol is currently the most used cardioplegia during minimally invasive cardiac surgery (MICS). Different randomized controlled trials compared blood and Custodiol cardioplegia in the context of traditional cardiac surgery. No data are available for MICS. The aim of this study was to compare the efficacy of cold blood versus Custodiol cardioplegia during MICS. We retrospectively evaluated 90 patients undergoing MICS through a right mini-thoracotomy in a three-year period. Myocardial protection was performed using cold blood (44 patients, CBC group) or Custodiol (46 patients, Custodiol group) cardioplegia, based on surgeon preference and complexity of surgery. The primary outcomes were post-operative cardiac troponin I (cTnI) and creatine kinase MB (CKMB) serum release and the incidence of Low Cardiac Output Syndrome (LCOS). Aortic cross-clamp and cardiopulmonary bypass times were higher in the Custodiol group. No difference was observed in myocardial injury enzyme release (peak cTnI value was 18±46 ng/ml in CBC and 21±37 ng/ml in Custodiol; p=0.245). No differences were observed for mortality, LCOS, atrial or ventricular arrhythmias onset, transfusions, mechanical ventilation time duration, intensive care unit and total hospital stay. Custodiol and cold blood cardioplegic solutions seem to assure similar myocardial protection in patients undergoing cardiac surgery through a right mini-thoracotomy approach.

Effects of delayed remote ischemic preconditioning on peri-operative myocardial injury in patients undergoing cardiac surgery — A randomized controlled trial

BackgroundRemote ischemic preconditioning (RIPC) has two time windows for organ protection: acute and delayed. Previous studies have mainly focused on the acute time window to evaluate organ protection by RIPC. We evaluated myocardial protection by delayed RIPC in adult patients undergoing cardiac surgery. MethodsA total of 160 adult patients undergoing cardiac surgery with cardiopulmonary bypass were randomized to receive either delayed RIPC (four cycles of 5min of ischemia followed by 5min of reperfusion by inflation to 200mmHg and deflation of a blood pressure cuff on the upper arm) or the control treatment 24–48h before surgery. The primary endpoint was post-operative troponin I levels serially measured for 72h. Secondary endpoints included post-operative serum creatinine levels, acute kidney injury, and composite complications. ResultsThere were no significant differences in post-operative troponin I values. The incidence of acute kidney injury, defined by the Acute Kidney Injury Network staging system, was lower in the delayed RIPC group compared to the control group (30.0% vs. 47.5%; relative risk, 0.768; 95% confidence interval, 0.599–0.985; p=0.023). Moreover, the occurrence of composite complications was lower in the delayed RIPC group compared with the control group (65.0% vs. 81.3%; relative risk, 0.536; 95% confidence interval, 0.311–0.924; p=0.020). ConclusionsWhile RIPC did not provide cardioprotective effects in patients undergoing cardiac surgery, it appeared to reduce acute kidney injury, as well as the rate of composite complications.

Kinetics of troponin I in patients with myocardial injury after noncardiac surgery.

Myocardial injury after noncardiac surgery, as measured by troponin elevation, is strongly associated with mortality. However, it is unknown in which patients prognosis can be improved. The presence of kinetic changes of troponin may be associated with a worse prognosis and warrant more aggressive management. Therefore, we aimed to study the kinetics of troponin in patients with postoperative myocardial injury, and to determine the added predictive value of kinetic changes of troponin on mortality. This cohort study included patients with myocardial injury after noncardiac surgery. Troponin I (TnI) was measured on the first three postoperative days. The primary outcome was all-cause 1-year mortality. We studied both absolute and relative TnI changes, and determined the delta TnI that was associated with mortality to distinguish a rise-and-fall TnI pattern from a stable TnI pattern. Next, we determined the added predictive value of a rise-and-fall TnI pattern for mortality. In total, 634 patients were included. The risk ratio (RR) for mortality increased significantly with an absolute delta TnI of ≥200 ng/L (RR 1.5, 99.4% CI 1.0-2.2, p=0.003). Using this delta TnI to define a rise-and-fall pattern, 459 patients (72%) had a stable TnI pattern and 175 patients (28%) had a rise-and-fall pattern. When added to a model including the highest TnI value and variables from the revised cardiac risk index (RCRI), the TnI pattern did not increase the predictive value for mortality. A postoperative TnI rise-and-fall pattern was associated with 1-year mortality, but had no added value in addition to the highest TnI level to predict 1-year mortality. Therefore, postoperative TnI kinetics are not useful for further mortality risk stratification in patients with myocardial injury after noncardiac surgery.