Postoperative Troponin Research Articles

Postoperative troponin increases after noncardiac surgery are associated with raised neurofilament light: a prospective observational cohort study

BackgroundMyocardial and neuronal injury occur commonly after noncardiac surgery. We examined whether patients who had perioperative myocardial injury (PMI) also incurred neuronal injury, and whether myocardial and neuronal injury were associated with similar changes in inflammatory markers or overlapping clinical predictors. MethodsA total of 114 individuals >65 yr old were recruited from two ongoing perioperative cohort studies (NCT02926417; NCT03124303). Plasma samples were collected before and daily after surgery to process assays for troponin I (PMI), neurofilament light (NfL; neuronal injury) and multiplexed plasma cytokines (inflammation). The primary outcome was the change in NfL in individuals with PMI (>40 pg ml−1 increase in troponin above preoperative values). We conducted logistic regression to identify if there were shared clinical predictors for myocardial and neuronal injury. ResultsNinety-six patients had paired NfL and troponin data. Twenty-three of 94 subjects (24%) with PMI had greater increases in NfL (median [inter-quartile range, IQR]: 29 pg ml−1 [3–95 pg ml−1]; 2.8-fold increase) compared with subjects with no troponin increase (8 pg ml−1 [3–20]; 1.3-fold increase; P=0.008). PMI was associated with increased interleukin (IL)-1ra (P=0.005), IL-2 (P=0.045), IL-8 (P=0.002), and IL-10 (P<0.001). Logistic regression showed that intraoperative hypotension was associated with PMI (P=0.043). Preoperative stroke (P=0.041) and blood loss (P=0.002), but not intraoperative hypotension, were associated with increased NfL. ConclusionsPostoperative troponin increases were associated with changes in NfL and inflammatory cytokines. Increases in troponin, but not NfL, were associated with intraoperative hypotension, suggesting differences in the mechanisms contributing to neuronal and myocardial injury.

MIDCAB vs OPCAB for severe coronary artery disease: a comparative study

Abstract Background/Introduction MIDCAB (minimally invasive direct coronary artery bypass surgery) ± PCI/DES was compared to classical “off pump” coronary artery bypass surgery (OPCAB) for the treatment of severe coronary artery disease. Purpose We hypothesized that MIDCAB is associated with reduced perioperative morbidity and mortality. Methods Preoperative and postoperative clinical data were collected prospectively in 329 consecutive patients with severe coronary artery disease undergoing either a MIDCAB procedure ± PCI/DES (MIDCAB group), n=118 patients, or classical OPCAB (OPCAB group), n=211 patients, at our institution from January 2017 to July 2019. A matched analysis using the EuroSCORE II (81 patients per group) was done. Results The median of EuroSCORE II was 1.05 in both groups, p=1. All MIDCAB patients underwent a left-sided mini-thoracotomy and received a single LIMA-LAD graft, OPCAB patients received median 3 distal anastomoses, p&amp;lt;0.001. Operative time was shorter in MIDCAB patients, 160min vs. 240min, p&amp;lt;0.001. Maximum postoperative Troponin levels were lower in MIDCAB compared to OPCAB, 105 μg/l vs. 260 μg/l, p&amp;lt;0.001. Intubation time was shorter in MIDCAB, 7.0 h vs. 9.3 h, p=0.04, as was ICU time, p=0.02. Chest tube drainage after 24 hours was lower in MIDCAB patients, 405 mL vs. 555 mL, p&amp;lt;0.001. Transfusions of blood, platelets and fresh frozen plasma were rarely needed. Transfusion of erythrocytes were more common in OPCAB, 19%, vs. MIDCAB, 2.5%, p=0.001. A transient neurological deficit showed one (1.2%) patient in the OPCAB group, non in MIDCAB, p=0.3. A hybrid procedure was performed in 18 MIDCAB patients (22%) and 5 OPCAB patients (6.2%). In-hospital mortality was 0% in the MIDCAB group, and 1.2% in OPCAB patients, p=0.3. Conclusions MIDCAB is a good and safe option to treat severe coronary artery disease. MIDCAB is not only less invasive, but associated with reduced perioperative risk compared to standard OPCAB surgery even if a hybrid procedure is needed. Funding Acknowledgement Type of funding source: None

Atrial nitroso-redox balance and refractoriness following on-pump cardiac surgery: a randomized trial of atorvastatin.

AimsSystemic inflammation and increased activity of atrial NOX2-containing NADPH oxidases have been associated with the new onset of atrial fibrillation (AF) after cardiac surgery. In addition to lowering LDL-cholesterol, statins exert rapid anti-inflammatory and antioxidant effects, the clinical significance of which remains controversial.Methods and resultsWe first assessed the impact of cardiac surgery and cardiopulmonary bypass (CPB) on atrial nitroso-redox balance by measuring NO synthase (NOS) and GTP cyclohydrolase-1 (GCH-1) activity, biopterin content, and superoxide production in paired samples of the right atrial appendage obtained before (PRE) and after CPB and reperfusion (POST) in 116 patients. The effect of perioperative treatment with atorvastatin (80 mg once daily) on these parameters, blood biomarkers, and the post-operative atrial effective refractory period (AERP) was then evaluated in a randomized, double-blind, placebo-controlled study in 80 patients undergoing cardiac surgery on CPB. CPB and reperfusion led to a significant increase in atrial superoxide production (74% CI 71–76%, n = 46 paired samples, P < 0.0001) and a reduction in atrial tetrahydrobiopterin (BH4) (34% CI 33–35%, n = 36 paired samples, P < 0.01), and in GCH-1 (56% CI 55–58%, n = 26 paired samples, P < 0.001) and NOS activity (58% CI 52–67%, n = 20 paired samples, P < 0.001). Perioperative atorvastatin treatment prevented the effect of CPB and reperfusion on all parameters but had no significant effect on the postoperative right AERP, troponin release, or NT-proBNP after cardiac surgery.ConclusionPerioperative statin therapy prevents post-reperfusion atrial nitroso-redox imbalance in patients undergoing on-pump cardiac surgery but has no significant impact on postoperative atrial refractoriness, perioperative myocardial injury, or markers of postoperative LV function.Clinical Trial Registration https://clinicaltrials.gov/ct2/show/NCT01780740

Routine use of del Nido cardioplegiacompared with blood cardioplegia in all types of adult cardiac surgery procedures.

Several studies reported the safety and potential benefits of single-dose Del Nido cardioplegia (DNC) in selected adult cardiac surgery (ACS) procedures. However, studies are scarce on routine use of DNC in more complex procedures and patients with a high risk profile. We sought to compare DNC with cold blood cardioplegia (BC) in all types of ACS including complex procedures. Data for 305 consecutive unselected patients who underwent ACS procedures (July/2017 to November/2019) were included. DNC was routinely used whenever is available (n = 231) and if not available, cold BC is used (n = 74). All categories of ACS procedures (primary or redo) were included. Repeated measures analysis was performed to compare baseline, peak, and trough Troponins levels in both groups. Linear regression analysis was used to identify independent predictors of peak Troponins level. The two groups were comparable in baseline characteristics including euro score (ES II), risk profile, and surgical complexity. DNC was associated with lower cardiopulmonary bypass (CPB) and cross-clamp times, cardioplegia volume, and number of cardioplegia doses (p < .001). Importantly, DNC was associated with lower postoperative Troponin level (p = .001), shorter duration of inotropic support (p = .02), and shorter intensive care unit stay (p = .04). On linear regression analysis, DNC was an independent predictor of lower postoperative peak Troponin (t = -3.5, p < .001). Routine use of DNC in all types of ACS procedures compared with BC was associated with significantly shorter CPB and clamp times, significantly lower postoperative troponin release, and shorter duration of inotropic support.

Association between postoperative haemoglobin and myocardial injury after noncardiac surgery: a retrospective cohort analysis

BackgroundMyocardial injury after noncardiac surgery (MINS) is common, mostly silent, and a strong predictor of postoperative mortality. MINS appears to result from myocardial supply–demand mismatch. Recent data support restrictive perioperative transfusion strategies that can result in low postoperative haemoglobin concentrations. Whether low postoperative haemoglobin is associated with myocardial injury remains unknown. We therefore tested the hypothesis that anaemia is associated with an increased risk of myocardial injury in adults having noncardiac surgery. MethodsWe conducted a retrospective analysis of adults ≥45 yr old who had routine postoperative troponin T (TnT) monitoring after noncardiac surgery at the Cleverland Clinic (including those enrolled in the PeriOperative ISchemic Evaluation-2 Trial [POISE-2], the Safety of Addition of Nitrous Oxide to General Anaesthesia in At-risk Patients Having Major Non-cardiac Surgery [ENIGMA-II], Vascular Events In Noncardiac Surgery Patients Cohort Evaluation Study [VISION], and Anaesthetic Depth and Complications After Major Surgery [BALANCED] trial). Patients with baseline increase in TnT and non-ischaemic aetiologies for TnT increase were excluded. The association between postoperative haemoglobin concentration during the 3 initial postoperative days and the incidence of MINS (fourth-generation TnT ≥0.03 ng ml−1 judged as attributable to ischaemia) was assessed using a time-varying covariate Cox proportional hazards survival analysis. ResultsAmong 6141 patients, 4480 were analysed. The incidence of MINS was 155/4480 (3.5%), ranging from 0/345 (0%) among patients whose lowest postoperative haemoglobin exceeded 13 g dl−1 to 52/611 (8.5%) in patients whose minimum postoperative haemoglobin was <8 g dl−1. The confounder-adjusted hazard ratio [95% confidence interval] for having MINS was 1.29 [1.16–1.42] for every 1 g dl−1 decrease in postoperative haemoglobin in a time-varying covariate analysis. Similar associations were identified in sensitivity analyses. ConclusionLower postoperative haemoglobin values are associated with MINS. Whether this association is modifiable by prevention or treatment of anaemia remains to be determined.

Off-pump coronary bypass grafting with or without the use of intracoronary shunts

Background: There is scarce literature comparing the role of the intracoronary shunt during off-pump coronary artery bypass grafting (CABG). This study aimed to compare off-pump CABG using intracoronary shunt versus the coronary clamp during distal coronary artery anastomosis.&#x0D; Methods: We conducted this randomized study between January and June 2018. We randomized 30 patients into two groups. Group A (n= 15) included patients who had coronary clamping during off-pump CABG, and Group B (n= 15) included patients who had intracoronary shunt during off-pump CABG. Study endpoints were anastomosis time and postoperative cardiac enzyme levels.&#x0D; Results: The mean age of the shunt group was higher than the mean age of the clamp group (61.06 ± 7.26 vs. 56.72 ± 12.44, respectively, p=0.03). Our study showed no statistical difference between the two groups regarding sex (p˃0.99), hypertension (p˃0.99), and diabetes (p=0.14). The distal anastomosis time was longer in the shunt group than in the clamp group (39.80±4.55 vs. 32.27±6.06 minutes, respectively, p=0.001). The postoperative troponin I (0.61±0.11 vs. 0.26±0.089 ƞg/ml, p&lt;0.001), and CK-MB levels (44.27±5.34 vs. 35.5±4.86 IU/L, p&lt;0.001) were significantly higher in the clamp group.&#x0D; Conclusion: The intracoronary shunt could be associated with lower cardiac enzyme release compared to the clamp technique. However, it was associated with a longer distal anastomosis time.

Myocardial injury after non-cardiac surgery (MINS) in EVAR patients: a retrospective single-centered study.

Myocardial injury after non-cardiac surgery (MINS) stands for myocardial injury due to ischemia that occurs during or within 30-days after non-cardiac surgery. Although MINS is known to be independently associated with 30-day mortality after intervention, little is described about the impact of MINS after vascular procedures, particularly after endovascular aneurysm repair (EVAR). This is an observational, retrospective, single-centered study. All patients underwent elective standard EVAR between January 2008 and June 2017, and them with at least one postoperative measurement of troponin I in the first 48 h after surgery, were retrospectively included. MINS was defined as the value exceeding the 99th percentile of a normal reference population with a coefficient of variation <10%. Primary outcomes include the prevalence of MINS in this subset of EVAR patients, as well as its impact in mid-term all-cause mortality. As secondary aim, the preoperative predictors of MINS were also assessed. One-hundred and thirty-six patients with postoperative troponin measurements were included (95.6% male; mean age 75.51years). MINS was diagnosed in 16.2% (N.=22) of the patients, and in 86.4% of the cases (N.=19) it was completely asymptomatic. Heart failure (31.8% vs. 10.5%, P=0.016), ASA Score ≥3 (95.5% vs. 67.5%, P=0.004), pre-operative (P=0.036) and postoperative (P=0.04) hemoglobin concentrations ≤12 g/dL were found to be significantly associated with MINS. Regarding remaining baseline characteristics, anesthesia and femoral access, no further differences were observed. Survival at 1, 3 and 5 years was 92% (95% CI: 4.6-6.9, standard error [SE] 0.023), 81% (95% CI: 5.6-7.6, SE=0.034) and 71% (95% CI: 6.9-8.7, SE=0.04), with two deaths reported at 30 days follow-up. MINS was found to be significantly associated with increased mid-term all-cause mortality after EVAR at 24 months follow-up (84.2±3.4% vs. 63.6±10.3%, P=0.001), with a 2.12-fold risk increase of death. MINS is a common complication after EVAR and negatively impacts the mid-term prognosis of such interventions. In the majority of cases, it is asymptomatic and, therefore, not detectable unless routine postoperative troponin measurements are performed.

Cardiac serum marker alterations after intraoperative radiotherapy with low-energy x-rays in early breast cancer as an indicator of possible cardiac toxicity

PurposeTo assess acute cardiac toxicity caused by intraoperative radiotherapy (IORT) with low-energy x‑rays for early breast cancer.MethodsWe prospectively analyzed pre- and postoperative troponin I and NT-proBNP in 94 women who underwent breast-conserving surgery between 2013 and 2017 at the Department of Gynecology and Obstetrics of the University Medical Center Mannheim, Germany. Thirty-nine women received IORT using low-energy x‑rays during breast-conserving surgery while 55 patients without IORT formed the control group. Demographic and surgical parameters as well as cardiac markers were evaluated.ResultsThere were no significant differences concerning age and side of breast cancer between the groups. Furthermore, no significant difference between the troponin I assays of the IORT and control groups could be found (preoperatively: 0.017 ± 0.006 ng/ml vs. 0.018 ± 0.008 ng/ml; p = 0.5105; postoperatively: 0.019 ± 0.012 ng/ml vs. 0.018 ± 0.010 ng/ml; p = 0.6225). N‑terminal fragment of B‑type natriuretic peptide (NT-proBNP) was significantly higher in the control group 24 h after surgery (preoperatively: 158.154 ± 169.427 pg/ml vs. 162.109 ± 147.343 pg/ml; p = 0.56; postoperatively: 168.846 ± 160.227 pg/ml vs. 232.527 ± 188.957 pg/ml; p = 0.0279).ConclusionTroponin I levels as a marker of acute cardiac toxicity did not show any significant differences in patients who received IORT during breast-conserving surgery compared to those who did not.

MicroRNA signatures of perioperative myocardial injury after elective noncardiac surgery: a prospective observational mechanistic cohort study

BackgroundElevated plasma or serum troponin, indicating perioperative myocardial injury (PMI), is common after noncardiac surgery. However, underlying mechanisms remain unclear. Acute coronary syndrome (ACS) is associated with the early appearance of circulating microRNAs, which regulate post-translational gene expression. We hypothesised that if PMI and ACS share pathophysiological mechanisms, common microRNA signatures should be evident. MethodsWe performed a nested case control study of samples obtained before and after noncardiac surgery from patients enrolled in two prospective observational studies of PMI (postoperative troponin I/T>99th centile). In cohort one, serum microRNAs were compared between patients with or without PMI, matched for age, gender, and comorbidity. Real-time polymerase chain reaction quantified (qRT–PCR) relative microRNA expression (cycle quantification [Cq] threshold <37) before and after surgery for microRNA signatures associated with ACS, blinded to PMI. In cohort two, we analysed (EdgeR) microRNA from plasma extracellular vesicles using next-generation sequencing (Illumina HiSeq 500). microRNA-messenger RNA-function pathway analysis was performed (DIANA miRPath v3.0/TopGO). ResultsMicroRNAs were detectable in all 59 patients (median age 67 yr [61–75]; 42% male), who had similar clinical characteristics independent of developing PMI. In cohort one, serum microRNA expression increased after surgery (mean fold-change) hsa-miR-1-3p: 3.99 (95% confidence interval [CI: 1.95–8.19]; hsa-miR-133-3p: 5.67 [95% CI: 2.94–10.91]; P<0.001). These changes were not associated with PMI. Bioinformatic analysis of differentially expressed microRNAs from cohorts one (n=48) and two (n=11) identified pathways associated with adrenergic stress and calcium dysregulation, rather than ischaemia. ConclusionsCirculating microRNAs associated with cardiac ischaemia were universally elevated in patients after surgery, independent of development of myocardial injury.

Postoperative visits by dedicated anesthesiologists in patients with elevated troponin: a retrospective cohort study evaluating postoperative care utility and early detection of complications

BackgroundAn elevated cardiac troponin level after noncardiac surgery is associated with both morbidity and mortality. Guidelines suggest routine troponin monitoring in high-risk patients. We implemented a dedicated anesthesia team to conduct follow-up on patients with postoperative troponin elevation. We hypothesized that these visits would facilitate early detection of complications. Therefore, the aim of this study was to evaluate the effect of postoperative visits by dedicated anesthesiologists on early detection of complications and care utility.MethodsThis retrospective observational study included patients aged ≥ 60 years with an elevated troponin within the first 3 days after noncardiac surgery. Troponin elevation was detected by routine biomarker monitoring. The primary outcome was early detected myocardial infarctions by the dedicated anesthesiologist. Other outcomes were overall detected complications, additional diagnostic tests and treatment advised by the anesthesiologist, consultation of another medical specialist, and advised postoperative follow-up at the outpatient cardiac clinic within 1 week after surgery.ResultsOf the 811 patients, 509 (63%) received a postoperative consultation by the anesthesiologist. Anesthesiologists were involved in the early detection of 59% of all myocardial infarctions and in 12% of all complications. Besides cardiac ischemia, patients were also often diagnosed with noncardiac complications, including respiratory failure (8.9%), pneumonia (13.2%), and acute kidney injury (17.5%) within 1 week after surgery. In 75% of patients, anesthesiologists ordered additional diagnostics, most frequently existing of electrocardiograms and additional cardiac enzyme testing. Additionally, change in treatment was advised, most often a medication change, in 16% of patients.ConclusionsStandard consultation of a dedicated anesthesiologist resulted in an early detection of 59% of all myocardial infarctions and involved a change in treatment in a considerable number of patients with postoperative troponin elevation. Whether this may improve patient outcomes remains to be elucidated.

Acute Postoperative Pain Is Associated With Myocardial Injury After Noncardiac Surgery.

Uncontrolled pain after noncardiac surgery activates the sympathetic nervous system, which causes tachycardia, hypertension, and increased cardiac contractility-all of which may increase myocardial oxygen demand. We therefore determined whether time-weighted average pain scores over the initial 72 postoperative hours are associated with myocardial injury after noncardiac surgery (MINS). We conducted a retrospective cohort analysis of adults with routine postoperative troponin monitoring after noncardiac surgery under general, regional, or combined anesthesia at tertiary level centers in Cleveland from January 2012 to December 2015. Time-weighted average pain scores were calculated from all the available pain scores, typically at 4-hour intervals, until a troponin elevation was detected. MINS was defined as peak troponin T concentrations exceeding 0.03 ng/mL within 72 hours after surgery. We used a generalized linear mixed model to assess the association between pain and MINS with 3 hospitals as clusters, adjusting for potential confounders. Among 2892 eligible patients, 4.5% had myocardial injury within 72 hours after surgery. Higher time-weighted average pain scores were associated with increased hazard of myocardial injury. The estimated hazard ratio for a 1-unit increase in pain score was 1.12 (95% confidence interval [CI], 1.02-1.22; P = .013), adjusting for confounding variables. Among patients undergoing noncardiac surgery, time-weighted average pain scores within 72 hours after surgery were significantly associated with myocardial injury.

Immediate postoperative high-sensitivity troponin T concentrations and long-term patient-reported health-related quality of life: A prospective cohort study.

Myocardial injury after noncardiac surgery is associated with mortality and major adverse postoperative cardiovascular events. The effect of postoperative troponin concentrations on patient-reported health-related quality of life (HRQoL) is unknown. The study examined the association between immediate postoperative troponin concentrations and self-reported HRQoL 1 year after surgery. Prospective cohort study. Single-centre tertiary care hospital in the Netherlands between July 2012 and 2015. Patients aged at least 60 years undergoing moderate and major noncardiac surgery. None. HRQoL total score was assessed with the EuroQol five-dimensional questionnaire. Tobit regression analysis was used to determine the association between postoperative troponin concentrations and 1-year HRQoL. Peak high-sensitivity troponin T values were divided into four categories: less than 14, 14 to 49, 50 to 149 and at least 150 ng l. A total of 3085 patients with troponin measurements were included. 2634 (85.4%) patients were alive at 1-year follow-up of whom 1297 (49.2%) returned a completed questionnaire. The median score for HRQoL was 0.82 (0.85, 0.81, 0.77 and 0.71 per increasing troponin category). Multivariable analysis revealed betas of -0.06 [95% confidence interval (CI) -0.09 to -0.02], -0.11 (95% CI -0.18 to -0.04) and -0.18 (95% CI -0.29 to -0.07) for troponin levels of 14 to 49, 50 to 149 and at least 150 ng l when compared with values less than 14 ng l. Other independent predictors for lower HRQoL were chronic obstructive pulmonary disease, female sex, peripheral arterial disease and increasing age. Higher levels of postoperative troponin measured immediately after surgery were independently associated with lower self-reported HRQoL total score at 1-year follow-up.

Prognostic value of high-sensitivity troponin I after cardiac surgery according to preoperative renal function.

Cardiac troponin levels can be elevated without myocardial injury in patients with renal impairment. However, the prognostic value of elevated troponin levels after cardiac surgery has not been well evaluated in patients with renal impairment. We evaluated the relationship between postoperative troponin levels and mortality following cardiac surgery according to preoperative renal function.Among 3661 patients underwent cardiac surgery between March 2005 and December 2015, 1909 patients were analyzed after excluding those with insufficient laboratory data, preoperative myocardial infarction, underwent Cox-Maze or redo surgery, or with a follow-up period <30 days. The primary outcome was risk of 30-day mortality according to elevated postoperative high-sensitivity cardiac troponin I (hs-cTnI) levels in varying degrees of renal function. Secondary outcomes included long-term cardiac-cause and all-cause mortality during the median follow-up of 52 months.After adjustment for risk factors, elevated peak postoperative hs-cTnI was associated with 30-day mortality [adjusted odds ratio 1.028, 95% confidence interval (CI) 1.013-1.043, P < .001], long-term cardiac-cause [adjusted hazard ratio (HR) 1.013, 95% CI 1.009-1.017, P < .001] and all-cause mortality (adjusted HR 1.013, 95% CI 1.009-1.016, P < .001), in patients with preoperative normal renal function [estimated glomerular filtration rate (eGFR) ≥60 ml/minute/1.73 m]. However, in patients with renal impairment (eGFR < 60 ml/minute/1.73 m), hs-cTnI levels were not associated with mortality following cardiac surgery.Elevated hs-cTnI levels following cardiac surgery did not predict short- and long-term mortality in patients with preoperative renal impairment.

The effect of supplemental oxygen on perioperative brain natriuretic peptide concentration in cardiac risk patients \u2013 a protocol for a prosprective randomized clinical trial

BackgroundElevated postoperative N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentrations are predictive for cardiac adverse events in noncardiac surgery. Studies indicate that supplemental oxygen decreases sympathetic nerve activity and might, therefore, improve cardiovascular function. Thus, we will test the effect of perioperative supplemental oxygen administration on NT-proBNP release after surgery.Methods/designWe will conduct a single-center, double-blinded, randomized trial at the Medical University of Vienna, including 260 patients with increased cardiac risk factors undergoing moderate- to high-risk noncardiac surgery. Patients will be randomly assigned to receive 80% versus 30% oxygen during surgery and for 2 h postoperatively. The primary outcome will be the difference in maximum NT-proBNP release after surgery.As secondary outcomes we will assess the effect of supplemental oxygen on postoperative maximum troponin T concentration, oxidation-reduction potential, von Willebrand factor concentration and perioperative fluid requirements. We will perform outcome measurements 2 h after surgery, on postoperative day 1 and on postoperative day 3. The NT-proBNP concentration and the oxidation-reduction potential will also be measured within 72 h before discharge.DiscussionOur trial should determine whether perioperative supplemental oxygen administration will reduce the postoperative release of NT-proBNP in patients with preoperative increased cardiovascular risk factors undergoing noncardiac surgery.Trial registrationClinicalTrials.gov, ID: NCT03366857. Registered on 8th December 2017.

Comparative study between the use of St. Thomas' II cardioplegia and del Nido cardioplegia in patients who underwent open-heart surgery

Background and Aims: Cardioplegia is used to arrest the heart after the application of an aortic cross-clamp that interrupts the coronary circulation. Commonly used St. Thomas’II cardioplegic solution has to be repeated at short intervals, which may cause additional myocardial injury. So, this study is done to determine whether del Nido (DN) cardioplegia, which has a longer duration of arrest with a single dose, provides equivalent or better myocardial protection as compared to St. Thomas’ II Cardioplegia.&#x0D; Methods: A prospective observational study was done among 100 patients who underwent open-heart surgery with myocardial protection, between September 2016 to August 2018 in Bangabandhu Sheikh Mujib Medical University, Bangladesh. Patients were divided into two groups, group A (n=50) for del Nido cardioplegic and group B (n=50) for St. Thomas’ II cardioplegia. We compared the amount of cardioplegic solution, Aortic cross-clamp time, cardiopulmonary bypass (CPB) time, ischemic time, arrhythmia, spontaneous sinus rhythm after declamping, intraoperative DC shock requirement, postoperative left ventricular ejection fraction, serum potassium level, low cardiac output, cardiac Troponin level I and CK-MB release after 12 hours and 24 hours, presence of myocardial infarction and death.&#x0D; Results: The per-operative variable suggested spontaneous activity during a cardiac arrest was 2% in del Nido and 14% in St. Thomas’ II group (p=0.044). Similarly, during intraoperative phase spontaneous restoration of cardiac activity after the procedure in del Nido was 2.90 ± 1.16 minutes and in St. Thomas’ II was 1.8 ± 0.615 minutes (p=0.001). However total bypass time and ischemic time were not significant. During the postoperative period, Troponin I and CKMB were measured at 12 hours and 24 hours which were not statistically different in two groups. Postoperatively, low output syndrome was seen among 3 patients in del Nido Group and 4 patients in St. Thomas’ II group (p-value=0.341).&#x0D; Conclusion: This study showed with the use of del Nido cardioplegia provides equivalent myocardial protection to St. Thomas’ II cardioplegia, with the use of only single-dose cardioplegia.

Abstract 324: Use of Troponin Testing After Non-cardiac Surgery in Ontario

Background: Myocardial infarction after non-cardiac surgery is common and associated with worse patient outcomes. In 2017, the Canadian Cardiovascular Society (CCS) published guidelines endorsing postoperative cardiac troponin surveillance in higher-risk patients having non-cardiac surgery. The objective of this study was to evaluate the proportion of non-cardiac surgery patients recommended for post-operative troponin testing and use of troponin testing in accordance with this guideline. Methods: We conducted a retrospective observational study of patients aged 40-105 years having moderate to high risk non-cardiac surgery in Ontario, Canada from January 1, 2010 to December 31, 2017. Classes of surgeries included orthopedics, gynecology, general, urology, vascular, and thoracic. Recommendations for troponin testing was determined by CCS criteria. Troponin testing within 2 days of the surgery was ascertained using the Ontario Laboratory Information System. Results: There were 268,269 patients in the cohort recommended for troponin testing during the study period. Mean age was 66.7 ± 11.9 years, 58.2% were female, and 12.3% underwent urgent surgery. According to CCS guidelines, 72.4% of elective surgery patients and 81.2% of urgent surgery patients would be recommended for post-operative troponin screening. The observed testing rate was 10.5% for elective patients and 26.4% for urgent surgery patients. Observed rates of testing for CCS recommended patients varied significantly by surgery: 5.5% for hysterectomies to 64.0% for open abdominal aortic aneurism repair (see Figure). Conclusions: Based on the current CCS guidelines, the majority of patients undergoing moderate to high-risk surgery should receive troponin testing. However, testing rates in Ontario were substantially lower with significant variations based on the type of surgery. The implication for routine troponin testing recommendation is substantial given the low utilization of troponin testing.

Very early postoperative troponin increase and clinical outcome in patients admitted to the recovery room after noncardiac surgery with suspected cardiac events

We assessed the prognostic meaning of very early (<6 h) troponin increase after noncardiac surgery in a population of patients admitted to the recovery room, for whom troponin measurements were taken because of a suspected cardiac event. Among a total of 296 patients, abnormal troponin was found in 24 (8.1%). Ten patients in this group (41.7%) and 27 among those with normal troponin (9.9%) experienced cardiovascular death, myocardial infarction, or decompensated heart failure at one month (p < 0.0001). Troponin was independently associated with a two-fold risk of events (p < 0.0001). In these patients, very early troponin measurement in the recovery room may help to identify patients at risk of cardiovascular events.

Prevalence of a postoperative troponin leak in patients with cardiac risk factors undergoing knee and hip arthroplasty in a South African population.

Patients undergoing arthroplasty may have comorbidities that put them at risk of myocardial injury after non-cardiac surgery (MINS). MINS, a new clinical concept that has a different pathophysiology from conventional myocardial infarction, is related to a supply-demand mismatch ischaemia in the perioperative setting. MINS is often a silent event, and the diagnosis relies on cardiac biomarker testing such as troponin T. The incidence is estimated at 40%, with a fourfold increase in morbidity and mortality risk 1 year post surgery. To determine the prevalence of postoperative troponin leak in a single-centre arthroplasty unit in patients with various cardiac risk factors undergoing hip or knee arthroplasty and investigate the differences in troponin T levels between comorbidities and different types of arthroplasty, i.e. total hip replacement (THR), total knee replacement (TKR) and neck of femur (NoF) fracture hip replacement. A prospective, cross-sectional study of patients with one or more cardiac risk factors undergoing replacement surgery was conducted from October 2017 to April 2018. Troponin levels of all included patients were recorded on days 1 and 3 post surgery using a high-sensitivity cardiac troponin T assay (Roche hs-cTnT). A level of &gt;15 ng/L is considered abnormal and termed a positive troponin leak, while &gt;100 ng/L is considered suspected acute coronary syndrome (ACS). One hundred and sixty patients (n=66 THR, n=55 NoF hip replacement, n=39 TKR) were included. Sixty-eight patients (42%) had a positive troponin leak, and in 6 of these cases ACS was suspected. The highest prevalence of troponin leak was recorded in patients undergoing NoF hip replacement (62%), followed by TKR (46%) and then THR (24%). Sixty-two patients (38%) had positive troponin levels on day 1 and 53 patients (33%) had positive levels on day 3. Important patient cardiac risk factors were identified in the presence of a positive troponin leak, with ischaemic heart disease, hypertension, diabetes, renal disease, age &gt;65 years and atrial fibrillation being statistically most likely. Postoperative troponin surveillance is an inexpensive and reliable way to identify patients at risk of MINS and subsequently enhance early detection, medical optimisation and referral strategies. Simple interventions may improve outcomes and contribute to lower ACS rates and the timeous prevention of other complications. The prevalence of MINS in orthopaedic-specific patients in South Africa (SA) and other resource-constrained developing countries is unknown. Our finding of 42% positive troponin leaks raises awareness of this issue, and we recommend routine postoperative troponin surveillance for all arthroplasty units in SA.

Microplegia vs 4:1 Blood Cardioplegia: Effectiveness and Cost Savings in Complex Cardiac Operations

Microplegia has been studied during isolated coronary artery bypass grafting and valve surgery but not in more complex operations. Objectives of this study were to demonstrate safety and effectiveness of microplegia relative to Buckberg cardioplegia during these operations. From January 2012 to January 2017, 242 patients underwent multicomponent operations with simplified microplegia delivered via syringe pump and 10,512 with modified Buckberg cardioplegia. Operations included aortic root, arch, or ascending aorta replacement in 424 (94%) patients, aortic valve surgery in 324 (72%) patients, and concomitant coronary artery bypass grafting in 47 (10%) patients. Outcomes were compared in 226 propensity-matched pairs. There was no difference in median postoperative troponin T between groups after adjusting foraortic clamp time. Microplegia patients received significantly less crystalloid with their cardioplegia (mean 27 ± 8.0 mL/operation vs 735 ± 357 mL/operation; P < .001) and had lower peak intraoperative glucose (196 ± 40 mg/dL vs 248 ± 69 mg/dL; P < .001). Microplegia and Buckberg groups had similar in-hospital mortality (2.7% [n= 6] vs 2.2% [n= 5]; P= .8), stroke (2.2% [n= 5] vs 3.6% [n= 8]; P= .4), renal failure (8% [n= 18] vs 5.8% [n= 13]; P= .4), prolonged ventilation (23% [n= 51] vs 24% [n= 54]; P= .7), median postoperative length of stay(both 8.1 days; P > .9), and median red cell units administered to patients requiring transfusion (4 units vs 3 units; P= .14). The mean cost of cardioplegia per case with microplegia was 1/26th that of Buckberg cardioplegia. Our simplified microplegia technique offers several advantages over Buckberg cardioplegia without compromising myocardial protection or safety in complex, multicomponent operations with extended aortic clamp times.

Postoperative high-sensitivity troponin T as a predictor of sudden cardiac arrest in patients undergoing cardiac surgery.

The usefulness of high-sensitivity troponin T (hs-TnT) as a predictor of sudden cardiac arrest (SCA) in patients undergoing valve surgery is currently unknown. A prospective study was conducted on a group of 815 consecutive patients with significant valvular heart disease that underwent elective valve surgery. The primary end-point was postoperative SCA. The postoperative SCA occurred in 26 patients. At multivariate analysis of hs-TnT measured immediately after surgery (hs-TnT I) and age remained independent predictors of the primary end-point. Elevated postoperative hs-TnT was associated with a higher risk of postoperative SCA.