Using postoperative cardiac Troponin-I (cTi) levels to detect myocardial ischaemia in patients undergoing vascular surgery

Atrial fibrillation in vascular surgery: a systematic review and meta-analysis on prevalence, incidence and outcome implications

AIMS

To know the prevalence of atrial fibrillation (AF), as well as the incidence of postoperative AF (POAF) in vascular surgery for arterial diseases and its outcome implications.

METHODS

We performed a systematic review and meta-analysis following the PRISMA statement.

RESULTS

After the selection process, we analyzed 44 records (30 for the prevalence of AF history and 14 for the incidence of POAF).The prevalence of history of AF was 11.5% [95% confidence interval (CI) 1-13.3] with high heterogeneity (I2 = 100%). Prevalence was higher in the case of endovascular procedures. History of AF was associated with a worse outcome in terms of in-hospital death [odds ratio (OR) 3.29; 95% CI 2.66-4.06; P < 0.0001; I2 94%] or stroke (OR 1.61; 95% CI 1.39-1.86; P < 0.0001; I2 91%).The pooled incidence of POAF was 3.6% (95% CI 2-6.4) with high heterogeneity (I2 = 100%). POAF risk was associated with older age (mean difference 4.67 years, 95% CI 2.38-6.96; P = 0.00007). The risk of POAF was lower in patients treated with endovascular procedures as compared with an open surgical procedure (OR 0.35; 95% CI 0.13-0.91; P = 0.03; I2 = 61%).

CONCLUSIONS

In the setting of vascular surgery for arterial diseases a history of AF is found overall in 11.5% of patients, more frequently in the case of endovascular procedures, and is associated with worse outcomes in terms of short-term mortality and stroke.The incidence of POAF is overall 3.6%, and is lower in patients treated with an endovascular procedure as compared with open surgery procedures. The need for oral anticoagulants for preventing AF-related stroke should be evaluated with randomized clinical trials.

Eversion Carotid Endarterectomy: Cardiac Troponin Assessment

Myocardial infarction (MI) is an eversion carotid endarterectomy (eCEA) complication, but most events are unknown, and true incidence and correlation remain controversial. Routine cardiac troponin measurement is a commonly used method for assessing early identification and treatment of MI and stratifying high-risk patients. The aim of the present study is to evaluate the effect of troponin elevation levels following eCEA and to investigate a possible correlation between adverse cardiovascular events and the incidence of postoperative myocardial infarction following emergent vascular surgery. The study included 54 patients who underwent eCEA. High-sensitive troponin I (hsTnI) levels were routinely monitored pre- and postoperatively, with an upper reference range of 34.5 pg/mL for men and 15.6 pg/mL for women. Increases were correlated with demographic and clinical risk factors, as well as clinical or subclinical cardiovascular events. hsTnI was increased in percentage (13%) postoperatively, and non-ST segment elevation MI was diagnosed in eight patients. No patient had clinical symptoms of MI and only two of them presented with simultaneous electrocardiographic changes. Increased levels did not correlate with comorbidities or other surgical risk factors. hsTnI elevation may occur in patients after eCEA and mostly correlates with silent non-ST segment elevation MI that occurred in the early postoperative phase, indicating a possible value as a tool for cardiovascular event diagnosis during the patient's hospitalization.

The myocardial protective effect of dexmedetomidine in high-risk patients undergoing aortic vascular surgery

Objective:

The aim of the study was to assess the effect of dexmedetomidine in high-risk patients undergoing aortic vascular surgery.

Design:

A randomized prospective study.

Setting:

Cairo University, Egypt.

Materials and Methods:

The study included 150 patients undergoing aortic vascular surgery.

Intervention:

The patients were classified into two groups (n = 75). Group D: The patients received a loading dose of 1 μg/kg dexmedetomidine over 15 min before induction and maintained as an infusion of 0.3 μg/kg/h to the end of the procedure. Group C: The patients received an equal volume of normal saline. The medication was prepared by the nursing staff and given to anesthetist blindly.

Measurements:

The monitors included the heart rate, mean arterial blood pressure, central venous pressure, electrocardiogram (ECG), serum troponin I level, end-tidal sevoflurane, and total dose of morphine in addition transthoracic echocardiography to the postoperative in cases with elevated serum troponin I level.

Main Results:

The dexmedetomidine decreased heart rate and minimized the changes in blood pressure compared to control group (P < 0.05). Furthermore, it decreased the incidence of myocardial ischemia reflected by troponin I level, ECG changes, and the development of new regional wall motion abnormalities (P < 0.05). Dexmedetomidine decreased the requirement for nitroglycerin and norepinephrine compared to control group (P < 0.05). The incidence of hypotension and bradycardia was significantly higher with dexmedetomidine (P < 0.05).

Conclusion:

The dexmedetomidine is safe and effective in patients undergoing aortic vascular surgery. It decreases the changes in heart rate and blood pressure during the procedures. It provides cardiac protection in high-risk patients reflected by decreasing the incidence of myocardial ischemia and serum level of troponin. The main side effects of dexmedetomidine were hypotension and bradycardia.

Myocardial infarction in intensive care units: A systematic review of diagnosis and treatment

INTRODUCTION

Patients in the intensive care unit are vulnerable to myocardial injury from a variety of causes, both ischaemic and non-ischaemic. It is challenging for ICU clinicians to apply the conventional guidance concerning diagnosis and treatment. We conducted this review to examine the evidence concerning diagnosis and treatment of myocardial infarction in the ICU.

METHODS

A systematic review was performed to identify relevant studies.

RESULTS

19 studies concerning use of ECG, cardiac enzymes, echocardiography and angiography were identified. 4 studies considered treatment of myocardial infarction.

CONCLUSIONS

Regular 12 lead ECG or 12 lead ECG monitoring is more sensitive than 2 lead monitoring, regular measurement of cardiac enzymes is more sensitive than when provoked by symptoms. Coronary angiography rarely identifies treatable lesions, without regional wall motion abnormality on echocardiography. Evidence relating to treatment was limited. A potential strategy to diagnose myocardial infarctions in the ICU is proposed.

Cardioprotective effects of monocyte locomotion inhibitory factor on myocardial ischemic injury by targeting vimentin

Monocyte locomotion inhibitory factor (MLIF), a heat-stable pentapeptide produced by Entamoeba histolytica, has anti-inflammatory function and protective effect on ischemic stroke. In this study, we evaluated the effect of MLIF on myocardial ischemia. Mice were subjected to ischemia/reperfusion by occlusion of the left anterior descending artery (LAD). After sacrifice, the serum concentrations of cardiac troponin I (cTnI), creatine kinase (CK), lactate dehydrogenase (LDH) as well as the heart infarct size were measured. HE and TUNEL staining were used to observe the pathological damage and the apoptotic cells. For in vitro study, the oxygen-glucose deprivation(OGD) model was established in H9c2 cells. MTT assay and flow cytometry assay were performed to evaluate cell viability and apoptosis. The expression of JNK and caspase 3 was assessed by western blot analysis. Pull-down assay was used to detect the specific binding protein of MLIF in myocardial cells. MLIF significantly reduced the infarct size, and the cTnI, CK and LDH levels, amelioratived pathological damage and reduced the apopotosis compared with the myocardial I/R model group. MLIF improved cell survival and inhibited apoptosis and necrosis by inhibiting the p-JNK and cleaved caspase3 expression. Furthermore, the binding protein of MLIF in myocardial cells was vimentin. Inhibition of vimentin expression by withaferin A or vimentin siRNA repressed the protective effects of MLIF in OGD-provoked H9c2 cells. Taken together, our results demonstrate that the cardioprotective effects of MLIF on myocardial ischemia injury are related to reductions in the inflammatory response and apoptosis by targeting vimentin.

Acute myocardial infarctation in patients with critical ischemia underwent lower limb revascularization

BACKGROUND: Atherosclerosis is the main cause of peripheral artery occlusive disease (PAOD) of the lower limbs. Patients with PAOD often also have obstructive atherosclerosis in other arterial sites, mainly the coronary arteries. This means that patients who undergo infrainguinal bypass to treat critical ischemia have a higher risk of AMI. There are, however, few reports in the literature that have assessed this risk properly. OBJECTIVE: The aim of this study was to determine the incidence of acute myocardial infarction in patients who underwent infrainguinal bypass to treat critical ischemia of the lower limbs caused by PAOD. MATERIAL AND METHODS: A total of 64 patients who underwent 82 infrainguinal bypass operations, from February 2011 to July 2012 were studied. All patients had electrocardiograms and troponin I blood assays during the postoperative period (within 72 hours). RESULTS: There were abnormal ECG findings and elevated blood troponin I levels suggestive of AMI in five (6%) of the 82 operations performed. All five had conventional surgery. The incidence of AMI as a proportion of the 52 conventional surgery cases was 9.6%. Two patients died. CONCLUSION: There was a 6% AMI incidence among patients who underwent infrainguinal bypass due to PAOD. Considering only cases operated using conventional surgery, the incidence of AMI was 9.6%.

High N-terminal pro-B-type natriuretic peptide: a biomarker of lung cancer?

BACKGROUND

The level of N-terminal pro-B-type natriuretic peptide (NT-proBNP) is affected by many known factors. Our study aimed to evaluate whether other factors, in particular lung cancer, could be responsible for an increase in NT-proBNP levels in a population with no known risk factors for elevated NT-proBNP.

PATIENTS AND METHODS

This study was based on the RIABO (Recueil de l'Ischémie au Bloc Opératoire) database, a single-center registry that prospectively records in elective noncardiac surgery. Patients aged > 75 years and those presenting with 1 or more known risk factors for high NT-proBNP were excluded. Patients were divided into 2 groups according to preoperative NT-proBNP levels: (≥ 125 pg/mL or < 125 pg/mL).

RESULTS

Between October 2005 and February 2007, 439 patients were eligible for inclusion. Among 35 patients with lung cancer, 26 (74%) had elevated NT-proBNP (≥ 125 pg/mL), versus 9 (26%) with NT-proBNP < 125 pg/mL (P < .0001). By multivariate analysis, the presence of lung cancer was an independent risk factor for a level of NT-proBNP ≥ 125 pg/mL (odds ratio, 7; 95% CI, 2.9-17; P < .0001). We also observed an independent relationship between NT-proBNP ≥ 125 pg/mL and age, female sex, smoking status, and C-reactive protein levels.

CONCLUSION

In our study, patients with lung cancer were 7 times more likely to have elevated NT-proBNP (≥ 125 pg/mL). The presence of lung cancer should therefore be taken into account when interpreting NT-proBNP levels. Further studies are warranted to explore the diagnostic value of this marker in lung cancer and to identify the cause of the elevation.

Perioperative cardiac damage in vascular surgery patients

BACKGROUND

Patients undergoing vascular surgery are at increased risk for developing cardiac complications. Majority of patients with perioperative myocardial damage are asymptomatic. Our objective is to review the available literature addressing the prevalence and prognostic implications of perioperative myocardial damage in vascular surgery patients.

METHODS

An Internet-based literature search was performed using MEDLINE to identify all published reports on perioperative myocardial damage in vascular surgery patients. Only those studies published from 2000 to 2010 evaluating myocardial damage using troponin I or T, with or without symptoms of angina pectoris were included.

RESULTS

Thirteen studies evaluating the prevalence of perioperative myocardial ischaemia or infarction were included in the study. The incidence of perioperative myocardial ischaemia ranged from 14% to 47% and the incidence of perioperative myocardial infarction ranged from 1% to 26%. In addition, 10 studies evaluating the prognostic value of perioperative myocardial ischaemia towards postoperative mortality or the occurrence of major adverse cardiac events were included. In the retrieved studies, hazard ratios varied from 1.9 to 9.0.

CONCLUSION

The high prevalence and asymptomatic nature of perioperative myocardial damage, combined with a substantial influence on postoperative mortality of vascular surgery patients, underline the importance of early detection and adequate management of perioperative myocardial damage. This article provides an extended overview regarding the prevalence and prognostic value of perioperative myocardial ischaemia and infarction in vascular surgery patients. In addition, treatment options to reduce the risk of perioperative myocardial damage are provided based on the current available literature.

[Cardiac biomarkers for diagnosis of myocardial infarction]

Diagnosis of postoperative myocardial infarction is often difficult, based on tools with a low sensitivity (clinical symptoms, EKG), or with a low specifity (old biomarkers, echocardiographic abnormalities) or inadequate for clinical practice (scintigraphy). Since 1995, clinicians may use more cardiospecific markers (troponin) allowing to modify strategy for postoperative myocardial infarction diagnosis. The aim of this review is to resume such an attitude.

Remote ischemic preconditioning reduces myocardial and renal injury after elective abdominal aortic aneurysm repair: a randomized controlled trial

BACKGROUND

Myocardial and renal injury commonly contribute to perioperative morbidity and mortality after abdominal aortic aneurysm repair. Remote ischemic preconditioning (RIPC) is a phenomenon whereby brief periods of ischemia followed by reperfusion in one organ provide systemic protection from prolonged ischemia. To investigate whether remote preconditioning reduces the incidence of myocardial and renal injury in patients undergoing elective open abdominal aortic aneurysm repair, we performed a randomized trial. METHOD AND RESULTS; Eighty-two patients were randomized to abdominal aortic aneurysm repair with RIPC or conventional abdominal aortic aneurysm repair (control). Two cycles of intermittent crossclamping of the common iliac artery with 10 minutes ischemia followed by 10 minutes reperfusion served as the RIPC stimulus. Myocardial injury was assessed by cardiac troponin I (>0.40 ng/mL), myocardial infarction by the American College of Cardiology/American Heart Association definition and renal injury by serum creatinine (>177 micromol/L) according to American Heart Association guidelines for risk stratification in major vascular surgery. The groups were well matched for baseline characteristics. RIPC reduced the incidence of myocardial injury by 27% (39% versus 12% [95% CI: 8.8% to 45%]; P=0.005), myocardial infarction by 22% (27% versus 5% [95% CI: 7.3% to 38%]; P=0.006), and renal impairment by 23% (30% versus 7%; [95% CI: 6.4 to 39]; P=0.009). Multivariable analysis revealed the protective effect of RIPC on myocardial injury (OR: 0.22, 95% CI: 0.07 to 0.67; P=0.008), myocardial infarction (OR: 0.18, 95% CI: 0.04 to 0.75; P=0.006) and renal impairment were independent of other covariables.

CONCLUSIONS

In patients undergoing elective open abdominal aortic aneurysm repair, RIPC reduces the incidence of postoperative myocardial injury, myocardial infarction, and renal impairment.

Predictors of Electrocardiographic Change, Cardiac Troponin Elevation, and Survival after Major Vascular Surgery: A Community Hospital Experience

Cardiovascular disease is the leading cause of perioperative morbidity and mortality after vascular surgery. The purpose of this study was to identify risk factors for myocardial ischemia after vascular surgery and to investigate a potential association of ischemia with mortality in a community hospital setting. A retrospective review was conducted after 190 major vascular procedures. Electrocardiogram (ECG) results and troponin I levels were obtained serially during the first 24 postoperative hours. Outcomes analyzed were ischemic ECG changes, troponin I level more than 2 ng/mL, 6-month mortality, and overall survival. The authors investigated any association of these outcomes with each other and the type of operation, history of coronary artery disease, diabetes, recent coronary intervention, age older than 70 years, or postoperative symptoms. Twenty-seven (14%) patients experienced ischemic ECG changes. Twenty-one (11%) patients experienced troponin I elevation. Univariate analysis revealed a history of coronary artery disease, diabetes, concerning symptoms, and troponin elevation to be predictive of ECG change ( P < 0.05). ECG change and symptoms were predictive of troponin elevation ( P < 0.01). Cox multivariate analysis revealed only infrainguinal bypass to predict 6-month mortality (odds ratio = 2.92, P = 0.02). Diabetes was the sole predictor of overall mortality (odds ratio = 1.94, P = 0.001). Nonsustained ischemic postoperative ECG changes during the first 24 postoperative hours do not independently influence 6-month or overall mortality after major vascular surgery. Postoperative troponin elevation likely conveys a mortality risk in the subsequent 6 months. In the community hospital setting, midterm survival rates after vascular surgery equivalent to those in higher volume centers can be achieved. Patients undergoing infrainguinal bypass and diabetics continue to be the most moribund vasculopaths.

Ischemic heart disease

Because of changing demographics, increasing numbers of patients with IHD are presenting for noncardiac surgery, and the risks of perioperative morbidity and mortality are significant. The Lee Cardiac Risk Index is applicable in defining perioperative cardiac risk: however, ACC/AHA guidelines may not be applicable comprehensively. The role of biomarkers in risk stratification still needs to be defined. Structured management protocols that help assess, diagnose, and treat patients with IHD preoperatively are likely to help decrease postoperative morbidity and mortality, but clearly are not applicable to all patients. Augmented hemodynamic control with beta-blockers or alpha-2 agonists and modulating inflammation by statins can play an important role in improving outcomes in many patients with IHD; preoperative coronary revascularization may be of limited value. Intraoperative anesthetic management that minimizes hemodynamic perturbations is important; however, the choice of a particular technique typically is not critical. Of critical importance is the postoperative management of the patient. Postoperative myocardial injury should be identified, evaluated, and managed aggressively. Secondary stresses such as sepsis, extubation, and anemia, which can increase demand on the heart, should be treated or minimized. Clearly, optimal care of the patient with IHD entails closely coordinated assessment and management throughout the preoperative, intraoperative, and postoperative phases, if one is to optimize short- and long-term outcomes.

[Infarction in the per-operative period: check-up, results, treatment, surveillance]

Peroperative infarction (POI) is a frequent and serious event, which is associated with an increase in morbidity and mortality; the risk is aggravated to varying degrees by the techniques of anaesthesia and surgery used. The preoperative evaluation of risk, which combines clinical and paraclinical criteria is described in the algorithm of the new AHA/ACC guidelines. In order to avert these ischemic episodes, beta-blockers must be continued or introduced during vascular surgery. In other types of surgery, they must be considered. It is difficult to diagnose MI in a per-operative context. The electrocardiogram print out and troponin kinetics will identify patients in the postoperative phase that should be oriented towards cardiovascular evaluation and therapy.

Methods of detecting atherosclerosis in non-cardiac surgical patients; the role of biochemical markers

Atherosclerosis is a common condition in both the developed and developing world and is now recognised to be an inflammatory condition leading to the development of ischaemic heart disease, cerebrovascular disease and peripheral vascular disease. Ischaemic heart disease is a major risk factor in the pathogenesis of perioperative adverse cardiovascular events which lead to significant morbidity and mortality within the high risk surgical patient population. Current methods of evaluating the likelihood of postoperative cardiovascular complications depend largely on risk scoring systems, and the preoperative assessment of the functional status of the cardiovascular system. However, the possible role of inflammation in the generation of atherosclerosis has led to the identification of several biochemical markers such as acute phase proteins, cellular adhesion molecules and cytokines. An alternative approach therefore is the measurement of preoperative levels of these biomarkers with the aim of assessing pre-existing disease activity. This review summarises the pathophysiology of atherosclerosis and perioperative myocardial infarction, and discusses the possible future role of biomarkers in the risk stratification of patients undergoing non-cardiac surgery.

Early increases in cardiac troponin levels after major vascular surgery is associated with an increased frequency of delayed cardiac complications

OBJECTIVE

To evaluate changes in cardiac troponin-I levels after major vascular surgery and their association with early and late postoperative cardiac complications.

DESIGN

Prospective, observational investigation.

SETTING

University teaching hospital.

PATIENTS

75 consecutive patients undergoing major vascular surgery.

INTERVENTIONS

All patients received a standard sevoflurane-fentanyl anesthesia during the procedure. Blood levels of creatine kinase with MB subtype and cardiac troponin-I were assessed before surgery and then everyday for the first 3 days after surgery. At the same time, 12-lead electrocardiography was also performed, and occurrence of any cardiac adverse event was recorded. Patients were then followed up for 1 month after surgery.

MEASUREMENT AND MAIN RESULTS

Troponin-I levels increased in 25 patients (33%) during the first 3 days after surgery; 9 of these patients (12%) had myocardial infarction. At univariate analysis, uncontrolled hypertension was the only risk factor for perioperative infarction (odds ratio, 16; (95% confidence interval, 3-74); however, multivariate logistic regression analysis failed to show statistically significant associations. Increases in troponin-I had a 100% sensitivity and 75% specificity in detecting myocardial ischemia with a 36% positive and 100% negative predictive values. Severe cardiac complication 1 month after surgery was reported in 5 patients (6.6%). The increase of cardiac troponin-I levels during the first 3 postoperative days was associated with an increased frequency of major cardiac complication at 1-month follow-up (P = 0.003), with a 100% sensitivity, 71% specificity, and 100% negative predictive value.

CONCLUSIONS

Myocardial infarction after major noncardiac vascular surgery occurs in up to 12% of cases. Perioperative monitoring of troponin-I plasma levels may help to identify patients at increased risk for cardiac morbidity not only early after surgery but also during the first postoperative month.

Anesthésie et réanimation pour chirurgie réglée de l'anévrisme de l'aorte abdominale

OBJECTIVES

Patient scheduled for infrarenal abdominal aortic aneurysm surgery carries a high risk of cardiac or respiratory comorbidity. To outline the perioperative management for these patients.

METHODS

Review of the literature using MesH Terms "abdominal aortic aneurysm", "anesthesia", "analgesia" "critical care" and/or "surgery" in Medline database.

RESULTS

Cardiac preoperative evaluation and management have recently been reviewed. Intermediate and high-risk patients should undergo non-invasive cardiac testing to decide between a preoperative medical strategy (using betablocker+/-statin and aspirin) and an interventional strategy (coronary angioplasty or cardiac surgery). Perioperative myocardial ischaemia should also be investigated by clinical, electrocardiographic and biologic monitoring such as plasmatic troponin Ic dosage. Specific score could also assess the respiratory failure risk preoperatively. Epidural analgesia decreases this risk. There is no evidence that a pharmacological treatment decreases the incidence of acute renal failure after aortic surgery. Endovascular repair is actually recommended for older, higher-risk patients or patients with a hostile abdomen or other technical factors that may complicate standard open repair.

Relationship between perioperative troponin elevation and other indicators of myocardial injury in vascular surgery patients

BACKGROUND

In 2000 the European Society of Cardiology and the American College of Cardiology published a consensus document revising the definition of myocardial infarction. The usefulness of this revised definition has been challenged. It has been suggested that, rather than any release of cardiac troponin being potentially diagnostic of myocardial infarction, a diagnostic threshold consistent with significant myocardial injury should be defined.

METHODS

We studied 65 patients undergoing elective major vascular surgery to examine the relationship between the magnitude of cardiac troponin I (cTnI) and creatine kinase MB fraction (CK-MB) release and clinical signs or symptoms of myocardial injury. cTnI and CK-MB concentrations were measured preoperatively and on the first 4 postoperative days using the ACCESS assay (Beckmann). Patients were considered to have suffered a perioperative myocardial infarction if they had either symptoms or ECG changes consistent with this diagnosis, together with cTnI release.

RESULTS

Peak postoperative cTnI concentrations above the lower detection limit of the ACCESS assay (0.06 microg litre(-1)) occurred in 26 patients. Eight of these patients displayed symptoms or ECG changes consistent with myocardial injury. A cTnI level greater than 0.68 microg litre(-1) was found to be consistent with the clinical diagnosis of myocardial infarction. The optimal cut-off for the diagnosis of MI using CK-MB was 40.4 microg litre(-1).

CONCLUSIONS

These data suggest that further studies are required to define the optimal cardiac troponin diagnostic threshold for the diagnosis of myocardial infarction in the non-cardiac surgery population.

Cardiac troponin I assessment and late cardiac complications after carotid stenting or endarterectomy

PURPOSE

When compared with carotid endarterectomy (CEA), percutaneous carotid angioplasty with stent replacement (CAS) is a less invasive technique in the treatment of carotid stenosis. However, periprocedural hemodynamic instability still remains a challenge. This instability might lead to myocardial damage, which is now measured accurately by using cardiac troponin I (CTnI).

METHODS

This study was designed to compare the periprocedural variation of CTnI in 150 consecutive patients scheduled to undergo CEA (n = 75) or CAS (n = 75). The levels of CTnI were measured until the third postoperative day in all patients. Short-term (1 month) and long-term (up to 5 years) postoperative cardiac outcome were assessed by means of chart review, regular follow-ups, and telephone calls.

RESULTS

There was not any statistically significant difference between the 2 groups regarding the demographic characteristics and preprocedural medical status. The incidence of increase of CTnI (>0.5 ng/mL) was significantly higher in the CEA group (13%) compared with that in the CAS group (1%; P = .001). During the acute postprocedural period, the CAS group was significantly more prone to hypotension, requiring vasopressor therapy, whereas the CEA group had more hypertension, necessitating hypotensive medications (P < .001). At 5 years, the overall incidence of major cardiac complications (nonfatal myocardial infarction and death related to cardiac origin) was significantly more frequent in the CEA group (20% vs 5%, P < .01).

CONCLUSION

The results of our study suggest that CAS yielded less myocardial damage in the short and long term when compared with CEA. Larger randomized multicenter trials with long-term outcomes are necessary to confirm our findings.

Peri-operative Myocardial Injury in Patients Undergoing Surgery for Critical Limb Ischaemia

INTRODUCTION

Although up to a half of patients undergoing abdominal aortic aneurysm (AAA) repair suffer myocardial injury, as indicated by a rise in cardiac troponin I (cTnI), this is infrequently accompanied by a rise in creatine kinase (CK)-MB fraction or electrocardiogram (ECG) changes. This study compares for the first time peri-operative cTnI, CK-MB and ECG changes in patients undergoing surgery for critical lower limb ischaemia (CLI).

METHODS

Twenty-nine patients (20 men, median age 75 [range, 57-95] years) were studied prospectively. cTnI, CK/CK-MB ratio and ECG were performed pre-operatively and on post-operative days 1, 2 and 3.

RESULTS

Eleven (38%) patients had an elevated cTnI >0.5 ng/ml. Five (17%) patients had an elevated CK-MB fraction >4% and all of these patients had an elevated cTnI. Eleven (38%) patients had ischaemic changes on ECG including seven of 11 (64%) patients with elevated cTnI and all five patients with elevated CK-MB fraction. There was no relationship between pre-operative cardiac status, antiplatelet use or type of anaesthesia and post-operative cTnI rise. Patients with a cTnI rise were younger (p=0.01), and were more likely to have presented with gangrene (p=0.04) and have a longer operation time (p=0.01) than patients who did not demonstrate a cTnI rise. Four patients developed clinically apparent cardiac complications: cardio-pulmonary arrest (n=1), cardiogenic shock (n=1), acute CCF (n=1) and rapid atrial fibrillation (n=1). Survival at 6 months was 26 of 29 (90%) patients.

CONCLUSION

These data demonstrate that over a third of patients operated for CLI sustain peri-operative myocardial injury, many of which are not clinically apparent. Pre-operative medical optimisation may improve prognosis in this group of patients.

Assessment and management of patients with ischemic heart disease

OBJECTIVE

Review the perioperative management of patients who are scheduled for noncardiac surgery.

DATA SOURCE

Review of literature (PubMed, MEDLINE).

CONCLUSIONS

Patients with ischemic heart disease who undergo noncardiac surgery are at significant risk of perioperative cardiac morbidity and mortality. Recent joint guidelines from the American College of Cardiology and American Heart Association have significantly streamlined the preoperative evaluation processes. Augmented hemodynamic control with intensive perioperative pharmacologic therapy with beta-blockers and possibly alpha-2 agonist has been shown to improve perioperative cardiovascular outcomes. However, translating this information to clinical practice continues to be a challenge and requires a multi- disciplinary approach. A particular intraoperative anesthetic technique is unlikely to influence perioperative cardiac morbidity and mortality. Postoperative management with goals of decreasing hemodynamic stress is important in patients with ischemic heart disease. Diagnosis and management of perioperative myocardial infarction continues to be a challenge. However, use of cardiac specific biomarkers should improve the diagnostic process.

Perioperative myocardial infarction in noncardiac surgery: the diagnostic and prognostic role of cardiac troponins

Despite the number of technologies used, the diagnosis of perioperative myocardial infarction is still a challenge. Studies conducted in surgical series have demonstrated that cardiac troponins (cTns) have both a superior diagnostic sensitivity and specificity, compared with other traditional techniques, and an independent power to predict short- and long-term prognosis. Nevertheless, some points need to be clarified. They include the usefulness of cTns in patients with end-stage renal failure; the standardization of the cTns cut-off for the diagnosis of myocardial injury; the timing of postoperative blood samplings; the cost-effectiveness of a screening in asymptomatic patients; and the possible therapeutic strategies.