Identification of myocardial injury using perioperative troponin surveillance in major noncardiac surgery and net benefit over the Revised Cardiac Risk Index

Pathophysiological mechanisms underlying increased circulating cardiac troponin in noncardiac surgery: a narrative review

Assay-specific increases in circulating cardiac troponin are observed in 20-40% of patients after noncardiac surgery, depending on patient age, type of surgery, and comorbidities. Increased cardiac troponin is consistently associated with excess morbidity and mortality after noncardiac surgery. Despite these findings, the underlying mechanisms are unclear. The majority of interventional trials have been designed on the premise that ischaemic cardiac disease drives elevated perioperative cardiac troponin concentrations. We consider data showing that elevated circulating cardiac troponin after surgery could be a nonspecific marker of cardiomyocyte stress. Elevated concentrations of circulating cardiac troponin could reflect coordinated pathological processes underpinning organ injury that are not necessarily caused by ischaemia. Laboratory studies suggest that matching of coronary artery autoregulation and myocardial perfusion-contraction coupling limit the impact of systemic haemodynamic changes in the myocardium, and that type 2 ischaemia might not be the likeliest explanation for cardiac troponin elevation in noncardiac surgery. The perioperative period triggers multiple pathological mechanisms that might cause cardiac troponin to cross the sarcolemma. A two-hit model involving two or more triggers including systemic inflammation, haemodynamic strain, adrenergic stress, and autonomic dysfunction might exacerbate or initiate acute myocardial injury directly in the absence of cell death. Consideration of these diverse mechanisms is pivotal for the design and interpretation of interventional perioperative trials.

Diagnostic and prognostic value of cardiac troponins in emergency department patients presenting after a fall: A prospective, multicenter study

BACKGROUND

Emergency department (ED) presentations after a ground-level fall (GLF) are common. Falls were suggested to be another possible presenting feature of a myocardial infarction (MI), as unrecognized MIs are common in older adults. Elevated high-sensitivity cardiac troponin (hs-cTn) concentrations could help determine the etiology of a GLF in ED. We investigated the prevalence of both MI and elevated high-sensitivity cardiac troponin T (hs-cTnT) and I (hs-cTnI), as well as the diagnostic accuracy of hs-cTnT and hs-cTnI regarding MI, and their prognostic value in older ED patients presenting after a GLF.

METHODS

This was a prospective, international, multicenter, cohort study with a follow-up of up to 1 year. Patients aged 65 years or older presenting to the ED after a GLF were prospectively enrolled. Two outcome assessors independently reviewed all discharge records to ascertain final gold standard diagnoses. Hs-cTnT and hs-cTnI levels were determined from thawed samples for every patient.

RESULTS

In total, 558 patients were included. Median (IQR) age was 83 (77-89) years, and 67.7% were female. Elevated hs-cTnT levels were found in 384 (68.8%) patients, and elevated hs-cTnI levels in 86 (15.4%) patients. Three patients (0.5%) were ascertained the gold standard diagnosis MI. Within 30 days, 18 (3.2%) patients had died. Nonsurvivors had higher hs-cTnT and hs-cTnI levels compared with survivors (hs-cTnT 40 [23-85] ng/L in nonsurvivors and 20 [13-33] ng/L in survivors; hs-cTnI 25 [14-54] ng/L in nonsurvivors and 8 [4-16] ng/L in survivors; p < 0.001 for both).

CONCLUSIONS

A majority of patients (n = 364, 68.8%) presenting to the ED after a fall had elevated hs-cTnT levels and 86 (15.4%) elevated hs-cTnI levels. However, the incidence of MI in these patients was low (n = 3, 0.5%). Our data do not support the opinion that falls may be a common presenting feature of MI. We discourage routine troponin testing in this population. However, hs-cTnT and hs-cTnI were both found to have prognostic properties for mortality prediction up to 1 year.

Positive effects of low-dose S-ketamine on preventing myocardial injury after thoracoscopic lobectomy in patients aged 70 to 85

OBJECTIVE

To investigate the effects of low-dose S-ketamine on marker of myocardial injury (BNP, hs-cTnT and HFABP) after thoracoscopic lobectomy in patients aged 70 to 85.

METHODS

One hundred patients (four cases excluded) aged 70-85 years, with body mass index 18-24 kg·m-2 and American Society of Anesthesiologists physical status II-III, scheduled for elective lobectomy from April 2022 to April 2023, were selected. The patients were divided into two groups by a random number table method, namely, the low-dose S-ketamine combined with GDFT group (group S) and the control group (group C), with 48 cases in each group. In group S, a low dose of S-ketamine (0.2 mg/kg) was given 1 min before intubation, and the maintenance dose was 0.12 mg·kg-1·h-1. Fluid therapy, guided by cardiac index (CI), changes in stroke volume (△SV), and other dynamic indicators, was used for rehydration during the operation. Group C was given the same amount of normal saline (0.2 mg/kg) 1 min before intubation, and the same rehydration therapy was adopted during the operation. The mean arterial pressure (MAP) and heart rate (HR) of the two groups were observed and recorded immediately after entering the operating room (T0), immediately after intubation (T1), immediately after the beginning of one-lung ventilation (OLV) (T2), immediately after the beginning of surgery (T3), immediately after the end of OLV (T4), and at the end of surgery (T5). The intraoperative fluid intake and output and the use of vasoactive drugs were recorded. The plasma levels of heart-type fatty acid-binding protein (HFABP), high-sensitivity troponin T (hs-cTnT), brain natriuretic peptide (BNP), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α) were recorded 24 h before operation and 24 and 48 h after operation. Visual analogue scale (VAS) pain scores at rest were recorded at 2 (V1), 6 (V2), 12 (V3), 24 (V4), and 48 h (V5) after operation, and the occurrence of myocardial ischemia during hospitalization was noted.

RESULTS

Compared with group C, MAP was significantly higher at T1-T5 in group S (P < 0.05), and the plasma concentrations of IL-6, IL-8, TNF-α, BNP, hs-cTnT, and HFABP were significantly lower at 24 and 48 h after operation (P < 0.05). The VAS pain scores at 2, 6, 12, 24, and 48 h after operation, the number of effective patient-controlled intravenous analgesia (PCIA) compressions, and the total number of PCIA compressions within 48 h after operation were significantly decreased (P < 0.05). Compared with group C, The hospitalization days, and the incidence of postoperative myocardial ischemia in group S were lower (P < 0.05). There were no significant intergroup differences in urine volume, extubation time, the incidence of postoperative atrial fibrillation, bleeding volume, colloid infusion volume, total fluid infusion volume, and the incidence of rescue analgesia.

CONCLUSIONS

Low-dose S-ketamine can reduce the levels of hs-cTnT, HFABP, and BNP in older patients after pulmonary lobectomy, which has a positive effect on preventing myocardial injury.

TRIAL REGISTRATION

This study was registered on CHICTR (registration No. ChiCTR2300074475). Date of registration: 08/08/2023.

High-Sensitivity Cardiac Troponin T and Frailty Predict Short-Term Mortality in Patients ≥75 Years Undergoing Emergency Abdominal Surgery: A Prospective Observational Study

BACKGROUND

An elevated cardiac troponin concentration is a prognostic factor for perioperative cardiac morbidity and mortality. In elderly patients undergoing emergency abdominal surgery, frailty is a recognized risk factor, but little is known about the prognostic value of cardiac troponin in these vulnerable patients. Therefore, we investigated the prognostic significance of elevated high-sensitivity cardiac troponin T (hs-cTnT) concentration and frailty in a cohort of elderly patients undergoing emergency abdominal surgery.

METHODS

We included consecutive patients ≥75 years of age who presented for emergency abdominal surgery, defined as abdominal pathology requiring surgery within 72 hours, in a university hospital in Norway. Patients who underwent vascular procedures or palliative surgery for inoperable malignancies were excluded. Preoperatively, frailty was assessed using the Clinical Frailty Scale (CFS), and blood samples were measured for hs-cTnT. We evaluated the predictive power of CFS and hs-cTnT concentrations using receiver operating characteristic (ROC) curves and Cox proportional hazard regression with 30-day mortality as the primary outcome. Secondary outcomes included (1) a composite of 30-day all-cause mortality and major adverse cardiac event (MACE), defined as myocardial infarction, nonfatal cardiac arrest, or coronary revascularization; and (2) 90-day mortality.

RESULTS

Of the 210 screened and 156 eligible patients, blood samples were available in 146, who were included. Troponin concentration exceeded the 99th percentile upper reference limit (URL) in 83% and 89% of the patients pre- and postoperatively. Of the participants, 53% were classified as vulnerable or frail (CFS ≥4). The 30-day mortality rate was 12% (18 of 146). Preoperatively, a threshold of hs-cTnT ≥34 ng/L independently predicted 30-day mortality (hazard ratio [HR] 3.14, 95% confidence interval [CI], 1.13-9.45), and the composite outcome of 30-day mortality and MACE (HR 2.58, 95% CI, 1.07-6.49). In this model, frailty (continuous CFS score) also independently predicted 30-day mortality (HR 1.42, 95% CI, 1.01-2.00) and 30-day mortality or MACE (HR 1.37, 95% CI, 1.02-1.84). The combination of troponin and frailty, 0.14 × hs-cTnT +4.0 × CFS, yielded apparent superior predictive power (area under the receiver operating characteristics curve [AUC] 0.79, 95% CI, 0.68-0.88), compared to troponin concentration (AUC 0.69, 95% CI, 0.55-0.83) or frailty (AUC 0.69, 95% CI, 0.57-0.82) alone.

CONCLUSIONS

After emergency abdominal surgery in elderly patients, increased preoperative troponin concentration and frailty were independent predictors of 30-day mortality. The combination of increased troponin concentration and frailty seemed to provide better prognostic information than troponin or frailty alone. These results must be validated in an independent sample.

[The role of cardiac biomarkers in perioperative risk evaluation of noncardiac surgery patients-A summary of the ESAIC guidelines 2023]

BACKGROUND

The recently published ESAIC guidelines highlight the clinical value of cardiac troponins (cTn) and B‑type natriuretic peptides (BNP) for risk assessment in patients undergoing noncardiac surgery.

OBJECTIVE

Summary of the ESAIC guideline recommendations.

MATERIAL AND METHODS

The evidence for the recommendations was extracted from studies that investigated the perioperative role of cTn and BNP as prognostic factors, for risk prediction and for therapeutic guidance. To collate this evidence 12 relevant endpoints as well as risk benefit analyses of systematic screening were considered to issue the strength of the recommendations.

RESULTS

The body of evidence for these guidelines was based on 115 studies. The evidence varied significantly across the 12 predefined endpoints. Additionally, there was a gradient in evidence for the use of cTn and BNP as prognostic factors, for risk prediction and for therapeutic guidance. The guidelines issue a weak recommendation for the use of preoperative, postoperative and combined measurement of cTn as well as for preoperative BNP measurement to assess the prognosis. For risk prediction a weak recommendation was formulated for combined and postoperative cTn and preoperative BNP measurements. No recommendation could be given for the evidence on biomarkers as data were very limited.

CONCLUSION

Both cTn and BNP can be used as prognostic factors or to predict the risk for selected endpoints. Therapeutic interventions should not be guided by cardiac biomarker levels.

ESAIC focused guideline for the use of cardiac biomarkers in perioperative risk evaluation

BACKGROUND

In recent years, there has been increasing focus on the use of cardiac biomarkers in patients undergoing noncardiac surgery.

AIMS

The aim of this focused guideline was to provide updated guidance regarding the pre-, post- and combined pre-and postoperative use of cardiac troponin and B-type natriuretic peptides in adult patients undergoing noncardiac surgery.

METHODS

The guidelines were prepared using Grading of Recommendations Assessment Development and Evaluation (GRADE) methodology. This included the definition of critical outcomes, a systematic literature search, appraisal of certainty of evidence, evaluation of biomarker measurement in terms of the balance of desirable and undesirable effects including clinical outcomes, resource use, health inequality, stakeholder acceptance, and implementation. The panel differentiated between three different scopes of applications: cardiac biomarkers as prognostic factors, as tools for risk prediction, and for biomarker-enhanced management strategies.

RESULTS

In a modified Delphi process, the task force defined 12 critical outcomes. The systematic literature search resulted in over 25,000 hits, of which 115 full-text articles formed the body of evidence for recommendations. The evidence appraisal indicated heterogeneity in the certainty of evidence across critical outcomes. Further, there was relevant gradient in the certainty of evidence across the three scopes of application. Recommendations were issued and if this was not possible due to limited evidence, clinical practice statements were produced.

CONCLUSION

The ESAIC focused guidelines provide guidance on the perioperative use of cardiac troponin and B-type natriuretic peptides in patients undergoing noncardiac surgery, for three different scopes of application.

Troponin elevation as a marker of short deterioration and one-year death in a high-risk surgical patient cohort in a low and middle income country setting: a postoperative approach to increase surveillance

PURPOSE

Myocardial injury after noncardiac surgery is common and mostly asymptomatic. The ideal target population that will benefit from routine troponin measurements in low and middle income countries (LMICs) is unclear. This study aims to evaluate the clinical outcomes of a cohort of high-risk surgical patients according to high-sensitivity troponin T (hsTnT) in an LMIC setting.

METHODS

We conducted a prospective cohort study of 442 high-risk patients undergoing noncardiac surgery at a Brazilian hospital between February 2019 and March 2020. High-sensitivity troponin T levels were measured preoperatively, 24 hr, and 48 hr after surgery and stratified into three groups: normal (< 20 ng·L-1); minor elevation (20-65 ng·L-1); and major elevation (> 65 ng·L-1). We performed survival analysis to determine the association between myocardial injury and one-year mortality. We described medical interventions and evaluated unplanned intensive care unit (ICU) admission and complications using multivariable models.

RESULTS

Postoperative myocardial injury occurred in 45% of patients. Overall, 30-day mortality was 8%. Thirty-day and one-year mortality were higher in patients with hsTnT ≥ 20 ng·L-1. One-year mortality was 18% in the unaltered troponin group vs 31% and 41% for minor and major elevation groups, respectively. Multivariable analysis of one-year survival showed a hazard ratio (HR) of 1.94 (95% confidence interval [CI], 1.22 to 3.09) for the minor elevation group and a HR of 2.73 (95% CI, 1.67 to 4.45) for the troponin > 65 ng·L-1 group. Patients with altered troponin had more unplanned ICU admissions (13% vs 5%) and more complications (78% vs 48%).

CONCLUSION

This study supports evidence that hsTnT is an important prognostic marker and a strong predictor of all-cause mortality after surgery. Troponin measurement in high-risk surgical patients could potentially be used as tool to scale-up care in LMIC settings.

STUDY REGISTRATION

ClinicalTrials.gov (NCT04187664); first submitted 5 December 2019.

Incidence and risk factors of postoperative acute myocardial injury in noncardiac patients: A systematic review and meta-analysis

INTRODUCTION

Postoperative myocardial injury after noncardiac surgery is common and is associated with short- and long-term morbidity and mortality. However, the incidence and risk factors for postoperative acute myocardial injury (POAMI) are currently unknown due to inconsistent definitions.

METHODS

We systematically searched PubMed and Web of Science to identify studies that applied the change value of preoperative and postoperative cardiac troponins to define cardiac injury. We estimated the pooled incidence, risk factors, and 30-day and long-term mortality of POAMI in noncardiac patients. The study protocol was registered with PROSPERO, CRD42023401607.

RESULTS

Ten cohorts containing 11,494 patients were included for analysis. The pooled incidence of POAMI was 20% (95% CI: 16% to 23%). Preoperative hypertension (OR: 1.47; 95% CI: 1.30 to 1.66), cardiac failure (OR: 2.63; 95% CI: 2.01 to 3.44), renal impairment (OR: 1.66; 95% CI: 1.48 to 1.86), diabetes (OR: 1.43; 95% CI: 1.27 to 1.61), and preoperative beta-blocker intake (OR: 1.65; 95% CI: 1.10 to 2.49) were the risk factors for POAMI. Age (mean difference: 2.08 years; 95% CI: -0.47 to 4.62), sex (male, OR: 1.16; 95% CI: 0.77 to 1.76), body mass index (mean difference: 0.35; 95% CI: -0.86 to 1.57), preoperative coronary artery disease (OR: 2.10; 95% CI: 0.85 to 5.21), stroke (OR: 0.90; 95% CI: 0.50 to 1.59) and preoperative statins intake (OR: 0.65; 95% CI: 0.21 to 2.02) were not associated with POAMI. Patients with POAMI had higher preoperative hsTnT levels (mean difference: 5.92 ng/L; 95% CI: 4.17 to 7.67) and lower preoperative hemoglobin levels (mean difference: -1.29 g/dL; 95% CI: -1.43 to -1.15) than patients without.

CONCLUSION

Based on this meta-analysis, approximately 1 in 5 of noncardiac patients develop POAMI. However, the lack of a universally recognized definition for POAMI, which incorporates diverse cardiac biomarkers and patient groups, poses a challenge in accurately characterizing its incidence, risk factors, and clinical outcomes.

Intraoperative Variables Enhance the Predictive Performance of Myocardial Injury in Patients with High Cardiovascular Risk After Thoracic Surgery When Added to Baseline Prediction Model

Purpose

Myocardial injury after non-cardiac surgery is closely related to major adverse cardiac and cerebrovascular event and is difficult to identify. This study aims to investigate how to predict the myocardial injury of thoracic surgery and whether intraoperative variables contribute to the prediction of myocardial injury.

Methods

The prospective study included adult patients with high cardiovascular risk who underwent elective thoracic surgery from May 2022 to October 2022. Multivariate logistic regression was used to establish a model with baseline variables and a model with baseline and intraoperative variables. We compare the predictive performance of two models for postoperative myocardial injury.

Results

In general, 31.5% (94 of 298) occurred myocardial injury. Age ≥65 years old, obesity, smoking, preoperative hsTnT, and one-lung ventilation time were independent predictors of myocardial injury. Compared with baseline model, the intraoperative variables improved model fit, modestly improved the reclassification (continuous net reclassification improvement 0.409, 95% CI, 0.169 to 0.648, P<0.001, improved integrated discrimination 0.036, 95% CI, 0.011 to 0.062, P<0.01) of myocardial injury cases, and achieved higher net benefit in decision curve analysis.

Conclusion

The risk stratification and anesthesia management of high-risk patients are essential. The addition of intraoperative variables to the baseline predictive model improved the performance of the overall model of myocardial injury and helped anesthesiologists screen out the patients at the greatest risk for myocardial injury and adjust anesthesia strategies.

Long-term outcomes of perioperative myocardial infarction/injury after non-cardiac surgery

AIMS

Perioperative myocardial infarction/injury (PMI) following non-cardiac surgery is a frequent cardiac complication. Better understanding of the underlying aetiologies and outcomes is urgently needed.

METHODS AND RESULTS

Aetiologies of PMIs detected within an active surveillance and response programme were centrally adjudicated by two independent physicians based on all information obtained during clinically indicated PMI work-up including cardiac imaging among consecutive high-risk patients undergoing major non-cardiac surgery in a prospective multicentre study. PMI aetiologies were hierarchically classified into 'extra-cardiac' if caused by a primarily extra-cardiac disease such as severe sepsis or pulmonary embolism; and 'cardiac', further subtyped into type 1 myocardial infarction (T1MI), tachyarrhythmia, acute heart failure (AHF), or likely type 2 myocardial infarction (lT2MI). Major adverse cardiac events (MACEs) including acute myocardial infarction, AHF (both only from day 3 to avoid inclusion bias), life-threatening arrhythmia, and cardiovascular death as well as all-cause death were assessed during 1-year follow-up. Among 7754 patients (age 45-98 years, 45% women), PMI occurred in 1016 (13.1%). At least one MACE occurred in 684/7754 patients (8.8%) and 818/7754 patients died (10.5%) within 1 year. Outcomes differed starkly according to aetiology: in patients with extra-cardiac PMI, T1MI, tachyarrhythmia, AHF, and lT2MI 51%, 41%, 57%, 64%, and 25% had MACE, and 38%, 27%, 40%, 49%, and 17% patients died within 1 year, respectively, compared to 7% and 9% in patients without PMI. These associations persisted in multivariable analysis.

CONCLUSION

At 1 year, most PMI aetiologies have unacceptably high rates of MACE and all-cause death, highlighting the urgent need for more intensive treatments.

STUDY REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT02573532.

Acute heart failure after non-cardiac surgery: incidence, phenotypes, determinants and outcomes

AIMS

Primary acute heart failure (AHF) is a common cause of hospitalization. AHF may also develop postoperatively (pAHF). The aim of this study was to assess the incidence, phenotypes, determinants and outcomes of pAHF following non-cardiac surgery.

METHODS AND RESULTS

A total of 9164 consecutive high-risk patients undergoing 11 262 non-cardiac inpatient surgeries were prospectively included. The incidence, phenotypes, determinants and outcome of pAHF, centrally adjudicated by independent cardiologists, were determined. The incidence of pAHF was 2.5% (95% confidence interval [CI] 2.2-2.8%); 51% of pAHF occurred in patients without known heart failure (de novo pAHF), and 49% in patients with chronic heart failure. Among patients with chronic heart failure, 10% developed pAHF, and among patients without a history of heart failure, 1.5% developed pAHF. Chronic heart failure, diabetes, urgent/emergent surgery, atrial fibrillation, cardiac troponin elevations above the 99th percentile, chronic obstructive pulmonary disease, anaemia, peripheral artery disease, coronary artery disease, and age, were independent predictors of pAHF in the logistic regression model. Patients with pAHF had significantly higher all-cause mortality (44% vs. 11%, p < 0.001) and AHF readmission (15% vs. 2%, p < 0.001) within 1 year than patients without pAHF. After Cox regression analysis, pAHF was an independent predictor of all-cause mortality (adjusted hazard ratio [aHR] 1.7 [95% CI 1.3-2.2]; p < 0.001) and AHF readmission (aHR 2.3 [95% CI 1.5-3.7]; p < 0.001). Findings were confirmed in an external validation cohort using a prospective multicentre cohort of 1250 patients (incidence of pAHF 2.4% [95% CI 1.6-3.3%]).

CONCLUSIONS

Postoperative AHF frequently developed following non-cardiac surgery, being de novo in half of cases, and associated with a very high mortality.

Perioperative troponin surveillance in major noncardiac surgery: a narrative review

Myocardial injury is now an acknowledged complication in patients undergoing noncardiac surgery. Heterogeneity in the definitions of myocardial injury contributes to difficulty in evaluating the value of cardiac troponins (cTns) measurement in perioperative care. Pre-, post-, and peri-operatively increased cTns are encompassed by the umbrella term 'myocardial injury' and are likely to reflect different pathophysiological mechanisms. Increased cTns are independently associated with cardiovascular and non-cardiovascular complications, poor short-term and long-term cardiovascular outcomes, and increased mortality. Preoperative measurement of cTns aids preoperative risk stratification beyond the Revised Cardiac Risk Index. Systematic measurement detects acute perioperative increases and allows early identification of acute myocardial injury. Common definitions and standards for reporting are a prerequisite for designing impactful future trials and perioperative management strategies.