Troponin I as a diagnostic marker of a perioperative myocardial infarction in the orthopedic population

Perioperative Cardiac Troponin I Levels in Patients Undergoing Total Hip and Total Knee Arthroplasty: A Single Center Study

Background

Cardiac injury is one of the significant perioperative complications in major orthopedic surgeries and its early diagnosis is useful in the reduction of postoperative comorbidity. The cardiac troponin is a sensitive and specific biomarker for detecting this damage.

Objectives

The aim of this study was to evaluate the levels of perioperative cardiac troponin I (cTnI) before and after arthroplasty in patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA). The effects of related variables and probable major cardiac complications were evaluated in this study.

Methods

For one year, in a prospective, cross-sectional study, the serum levels of cTnI before and 48 hours after arthroplasty were evaluated in 52 patients. Possible contributing factors including age, gender, body mass index (BMI), daily activity, history of hospitalization due to cardiovascular diseases, underlying illness, and medications were recorded. The Chi-square test, Pearson correlation, and Spearman test were used to examine the relationship between variables.

Results

The mean cTnI increased significantly after arthroplasty (P < 0.001). There was no significant relationship between age (P = 0.708), gender (P = 0.225), BMI (P = 0.195), daily activity (0.441), underlying illness (P = 0.244), and cTnI levels after arthroplasty. Linear regression showed BMI was significantly correlated with troponin changes (P = 0.006). Five patients had heart palpitations and one had chest pain, but none of the patients had any findings in favor of cardiac injury.

Conclusions

cTnI levels after THA and TKA increased significantly, but this elevation was in the normal range. In addition, none of them had a new cardiac complication after arthroplasty.

Impact of Age on 30-day Complications After Adult Deformity Surgery

STUDY DESIGN

A retrospective analysis.

OBJECTIVE

The aim of this study was to identify whether age is a risk factor for postoperative complications after adult deformity surgery (ADS).

SUMMARY OF BACKGROUND DATA

Spinal deformity is a prevalent cause of morbidity in the elderly population, occurring in as many as 68% of patients older than 60 years. Given the increasing prevalence of adult spinal deformities and an aging population, understanding the safety of ADS in elderly patients is becoming increasingly important.

METHODS

A retrospective cohort analysis was performed on the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database from 2010 to 2014. Patients (≥18 years of age) from the NSQIP database undergoing ADS were separated into age-based cohorts (≤52, 53-61, 62-69, and ≥70 years of age). Age groups were determined by interquartile analysis. Chi-squared, t tests, and multivariate logistic regression models were used to identify independent risk factors.

RESULTS

A total of 5805 patients met the inclusion criteria. Age groups 1, 2, 3, and 4 contained 1518 (26.1%), 1478 (25.4%), 1451 (25.0%), and 1358 (23.4%) patients, respectively. Multivariate logistic regression analysis revealed increasing age (relative to age group 1) to be an independent risk factor for prolonged length of stay [odds ratio (OR) 1.39, confidence interval (CI) 1.12-1.69], all complications (OR 1.64, CI 1.35-2.00), renal complications (OR 3.45, CI 1.43-8.33), urinary tract infection (OR 2.70, CI 1.49-4.76), postoperative transfusion (OR 1.47, CI 1.20-1.82), and unplanned readmission (OR 1.64, CI 1.18-2.23). Gradations in ORs existed between the different cohorts, such that the deleterious effect of age was less pronounced in cohort 3 compared with cohort 4, and even more less so between cohort 2 and cohort 4.

CONCLUSION

Age has been shown to be an independent risk factor for increased length of stay, all complications, renal complications, urinary tract infection, transfusion, and unplanned readmission.

LEVEL OF EVIDENCE

3.

The Incidence of Perioperative Cardiac Events after Orthopedic Surgery: A Single Institutional Experience of Cases Performed over One Year

BACKGROUND

Orthopedic patients with ischemic heart disease are at risk for postoperative cardiac complications.

QUESTIONS/PURPOSES

Using information from two medical information retrieval systems which insured the capture of all events for the period of study, our goals were to determine the incidence of myocardial injury in at-risk patients after orthopedic surgery and to delineate the type and incidence of cardiac complications in this population.

METHODS

For one year, at an orthopedic hospital, we identified all postoperative patients with a measured cTnI level using an electronic ordering system. Preoperative cardiac risk factors and postoperative cardiac complications were identified in patients undergoing a total hip arthroplasty (THA), total knee arthroplasty (TKA), and posterior spinal fusion (PSF). A postoperative myocardial infarction was defined by a cTnI > 0.1 ng/mL, ECG changes, new echocardiographic regional wall motion abnormalities, and evaluation by a cardiologist. Categorical variables were compared among groups with a Fisher's exact or Chi-square test. Continuous variables were compared among groups with ANOVA or the Kruskal-Wallis test. The associations of cardiac risk factors with myocardial injury are expressed as odds ratios from logistic regression models.

RESULTS

During a one-year period, from 10,627 inpatient orthopedic procedures, 805 patients were identified as at risk for postoperative myocardial ischemia. A total of 20.6% (166/805) of these patients had elevated serum cTnI levels (cTnI > 0.02 ng/mL), and there were ten documented postoperative MIs (10/805; 1.2%). For the at-risk TKA, THA, or PSF patients, 19% (102/532) had elevated cTnI levels and 31% (32/102) had postoperative cardiac complications, including arrhythmias (56%), congestive heart failure (2%), and MI (1%). Adjusting for sex, age, BMI, cardiac risk factors, and medications (statins and β-blockers), PSF patients had 3.9 times the risk of myocardial injury (p = 0.003) compared to TKA patients and 4.2 times that of THA patients.

CONCLUSIONS

The incidence of postoperative myocardial ischemia after major orthopedic surgery in patients with cardiac risk factors is high (8.7%), but the incidence of documented myocardial infarctions and serious cardiac complications remains low (1.2-2%). Patients with higher postoperative cTnI releases were more likely to have cardiac complications, and some procedures (spinal fusions) placed the patients at a higher risk.

Relation of perioperative elevation of troponin to long-term mortality after orthopedic surgery

Myocardial necrosis in the perioperative period of noncardiac surgery is associated with short-term mortality, but long-term outcomes have not been characterized. We investigated the association between perioperative troponin elevation and long-term mortality in a retrospective study of consecutive subjects who underwent hip, knee, and spine surgery. Perioperative myocardial necrosis and International Classification of Disease, Ninth Revision-coded myocardial infarction (MI) were recorded. Long-term survival was assessed using the Social Security Death Index database. Logistic regression models were used to identify independent predictors of long-term mortality. A total of 3,050 subjects underwent surgery. Mean age was 60.8 years, and 59% were women. Postoperative troponin was measured in 1,055 subjects (34.6%). Myocardial necrosis occurred in 179 cases (5.9%), and MI was coded in 20 (0.7%). Over 9,015 patient-years of follow-up, 111 deaths (3.6%) occurred. Long-term mortality was 16.8% in subjects with myocardial necrosis and 5.8% with a troponin in the normal range. Perioperative troponin elevation (hazard ratio 2.33, 95% confidence interval 1.33 to 4.10) and coded postoperative MI (adjusted hazard ratio 3.51, 95% confidence interval 1.44 to 8.53) were significantly associated with long-term mortality after multivariable adjustment. After excluding patients with coronary artery disease and renal dysfunction, myocardial necrosis remained associated with long-term mortality. In conclusion, postoperative myocardial necrosis is common after orthopedic surgery. Myocardial necrosis is independently associated with long-term mortality at 3 years and may be used to identify patients at higher risk for events who may benefit from aggressive management of cardiovascular risk factors.

Thrombotic and bleeding complications after orthopedic surgery

BACKGROUND

Thrombotic and bleeding complications are major concerns during orthopedic surgery. Given the frequency of orthopedic surgical procedures and the limited data in the literature, we sought to investigate the incidence and risk factors for thrombotic (myocardial necrosis and infarction) and bleeding events in patients undergoing orthopedic surgery.

METHODS AND RESULTS

We performed a retrospective cohort analysis of 3,082 consecutive subjects ≥21 years of age undergoing hip, knee, or spine surgery between November 1, 2008, and December 31, 2009. Patient characteristics were ascertained using International Classification of Diseases, Ninth Revision, diagnosis coding and retrospective review of medical records, and laboratory/blood bank databases. In-hospital outcomes included myocardial necrosis (elevated troponin), major bleeding, coded myocardial infarction, and coded hemorrhage as defined by International Classification of Diseases, Ninth Revision, coding. Of the 3,082 subjects, mean age was 60.8 ± 13.3 years, and 59% were female. Myocardial necrosis, coded myocardial infarction, major bleeding, and coded hemorrhage occurred in 179 (5.8%), 20 (0.7%), 165 (5.4%), and 26 (0.8%) subjects, respectively. Increasing age (P < .001), coronary artery disease (P < .001), cancer (P = .004), and chronic kidney disease (P = .01) were independent predictors of myocardial necrosis, whereas procedure type (P < .001), cancer (P < .001), female sex (P < .001), coronary artery disease (P < .001), and chronic obstructive pulmonary disease (P = .01) were independent predictors of major bleeding.

CONCLUSION

There is a delicate balance between thrombotic and bleeding events in the perioperative period after orthopedic surgery. Perioperative risk of both thrombosis and bleeding deserves careful attention in preoperative evaluation, and future prospective studies aimed at attenuating this risk are warranted.

Electrocardiograph Changes, Troponin Levels and Cardiac Complications After Orthopaedic Surgery

Introduction: The relationship between electrocardiograph (ECG) changes and troponin levels after the emergency orthopaedic surgery are not well characterised. The aim of this study was to determine the correlation between ECG changes (ischaemia or arrhythmia), troponin elevations perioperatively and cardiac complications. Materials and Methods: One hundred and eighty-seven orthopaedic patients over 60 years of age were prospectively tested for troponin I and ECGs were performed on the first 3 postoperative mornings or until discharge. Results: The incidences of pre- and postoperative troponin elevation were 15.5% and 37.4% respectively, the majority were asymptomatically detected. Most of the patients who sustained a troponin rise did not have any concomitant ECG changes (51/70 or 72.9%). Postoperative ECG changes were noted in 18.4% (34/185) and of those with ECG changes, slightly more than half (55.9%) had a troponin elevation. Most ECG changes occurred on postoperative day 1 and were non-ST elevation in type. ECG changes occurred more frequently with higher troponin levels. Postoperative troponin elevation (P = 0.018) and not preoperative troponin level (P = 0.060) was associated with ECG changes on univariate analysis. Two premorbid factors were predictors of postoperative ECG changes using multivariate logistical regression; age [odds ratio (OR), 1.05; 95% CI, 1.005 to 1.100, P = 0.029) and sex OR, 2.4; 95% CI, 1.069 to 5.446, P = 0.034). Twenty patients sustained postoperative cardiac complications; 9 (45%) were associated with ECG changes and 16 (80%) with postoperative troponin elevation. Pre- or postoperative troponin elevation better predicted cardiac complications compared with preoperative ECG changes. Conclusion: Electrocardiograph changes do not necessarily accompany troponin elevations after the emergency orthopaedic surgery but are more likely to have higher troponin levels. The best predictor of postoperative cardiac complications is troponin elevation. Key words: Cardiovascular, Fracture, Myocardial ischaemia, Myocardial infarction, Surgery

Does cardiology intervention improve mortality for post-operative troponin elevations after emergency orthopaedic-geriatric surgery? A randomised controlled study

OBJECTIVES

Troponin elevations are common after emergency orthopaedic surgery and confer a higher mortality at one year. The objective was to determine if comprehensive cardiology care after emergency orthopaedic surgery reduces mortality at one year in patients who sustain a post-operative troponin elevation versus standard care.

METHODS

A randomised controlled trial was conducted at a metropolitan teaching hospital in Melbourne, Australia. 187 consecutive patients were eligible with 70 patients randomised. Troponin I was tested peri-operatively and patients with a troponin elevation were randomised to cardiology care versus standard ward management. The main outcome measure was one year mortality.

RESULTS

The incidence of a post-operative troponin elevation was 37.4% (70/187) and these 70 patients were randomised. In-hospital cardiac complications were similar between the randomised groups: standard care (7/35 or 20.0%) versus cardiology care (8/35 or 22.9%). There was no difference in 1 year mortality between the randomised groups (6/35 or 17.1% in each group). Multivariate predictors of 1 year mortality were post-operative troponin elevation OR 4.3 (95% CI, 1.1-16.4, p=0.035), age OR 1.1 (95% CI, 1.02-1.2, p=0.016) and number of comorbidities OR 2.1 (95% CI, 1.3-3.5, p=0.004). At 1 year 35/187 (18.7%) sustained a cardiac complication and 23/35 (65.7%) had a troponin elevation.

CONCLUSIONS

There was no difference in mortality between patients with a post-operative troponin elevation randomised to cardiology care compared with standard care. Troponin elevation predicted one year mortality. Further research is needed to find an effective intervention to reduce mortality.

Troponin T in hip fracture patients: prognostic significance for mortality at one year

Hip fractures are common injuries in the elderly, with significant mortality and morbidity from several factors. Many of these patients have cardiac disease, and some develop cardiac complications which may increase mortality. Troponin T is a marker of myocardial injury but can be raised in other conditions. Patients over 60 years admitted with hip fracture during the study period had their troponin T measured on admission and postoperatively. Assay was performed after the patient had completed their treatment. We report the results of this study one year after the last patient was admitted. 108 patients were recruited. The average age was 84 years, 86% were female. The mean hospital stay was 20 days. This study found that 27% of hip fracture patients had some increase in the troponin T levels in the peri-operative period. This increase was not associated with an increase in early mortality, but there was an increase in one-year mortality for those with an increase in troponin T (45% versus 22%, p=0.03). These findings indicate that the routine measurement of troponin T does not correlate with acute mortality and is not necessary without evidence of an acute cardiac event.

[Symptomatic acute coronary syndrome in a cohort of patients followed after noncardiac surgery]

OBJECTIVES

To determine the incidence of acute coronary syndrome (ACS) with and without ST-segment elevation, factors related to the development of ACS, mean hospital stay, and attributable mortality.

MATERIAL AND METHODS

In a noncardiac surgery cohort attended in the postoperative critical care unit of Hospital General de la Ciudad Real, Spain, data were recorded prospectively between April 2006 and December 2009. The incidence of symptomatic ACS was calculated.

RESULTS

Thirty-two of 1919 patients developed ACS (incidence, 1.7%). Patient factors related to developing the syndrome were male sex (P=.046), age (P=.001), arterial hypertension (68.8%, P=.012), and a history of ischemic heart disease (34.4%, P=.001). Types of surgery that were significantly related to developing ACS were general surgery (37.5%), orthopedic or trauma surgery (28.1%), and vascular surgery (15.6%) (P<.004). Twenty percent of the cohort received transfusions; 50% of those who developed ACS were transfused (P=.001). The condition was treated medically in 87.5% of the cases. The mean (SD) duration of hospital stay was 2.96 (6.3) days for the cohort and 3.88 (5) days for patients who developed ACS (P=.39); mortality rates were 5% and 6%, respectively (P=.45). Multivariate analysis confirmed that the following independent variables were associated with developing postoperative ACS: a history of ischemic heart disease (odds ratio [OR], 4.59; 95% confidence interval [CI], 1.98-10.62) and intraoperative bleeding (OR, 3.18; 95% CI, 1.51-6.71). Gynecologic surgery patients were the least likely to develop postoperative ACS (OR, 0.063; 95% CI, 0.004-1.09).

CONCLUSIONS

The incidence of postoperative ACS in this noncardiac surgery cohort was 1.7%. Age, male sex, a history of arterial hypertension or ischemic heart disease, type of surgery, and intraoperative bleeding requiring transfusion of packed red blood cells are factors that are associated with developing this complication. Given the seriousness of ACS it is important to classify patients by risk before surgery.

Complications and outcomes after spinal deformity surgery in the elderly: review of the existing literature and future directions

Object

The elderly population (age > 60 years) is the fastest-growing age group in the US. Spinal deformity is a major problem affecting the elderly and, therefore, the demand for surgery for spinal deformity is becoming increasingly prevalent in elderly patients. Much of the literature on surgery for adult deformity focuses on patients who are younger than 60 years, and therefore there is limited information about the complications and outcomes of surgery in the elderly population.

In this study, the authors undertook a review of the literature on spinal deformity surgery in patients older than 60 years. The authors discuss their analysis with a focus on outcomes, complications, discrepancies between individual studies, and strategies for complication avoidance.

Methods

A systematic review of the MEDLINE and PubMed databases was performed to identify articles published from 1950 to the present using the following key words: “adult scoliosis surgery” and “adult spine deformity surgery.” Exclusion criteria included patient age younger than 60 years. Data on major Oswestry Disability Index (ODI) scores, visual analog scale (VAS) scores, patient-reported outcomes, and complications were recorded.

Results

Twenty-two articles were obtained and are included in this review. The mean age was 74.2 years, and the mean follow-up period was 3 years. The mean preoperative ODI was 48.6, and the mean postoperative reduction in ODI was 24.1. The mean preoperative VAS score was 7.7 with a mean postoperative decrease of 5.2. There were 311 reported complications for 815 patients (38%) and 5 deaths for 659 patients (< 1%).

Conclusions

Elderly patient outcomes were inconsistent in the published studies. Overall, most elderly patients obtained favorable outcomes with low operative mortality following surgery for adult spinal deformity.

Cardiac injury and troponin testing after orthopaedic surgery

BACKGROUND

Cardiac injury after orthopaedic surgery is an increasing problem particularly in an ageing population. The detection of cardiac injury has been aided by the use of cardiac troponins which has also raised questions about the utility of this enzyme in the post-operative setting.

OBJECTIVE

This review evaluates the diagnosis and pathophysiology of myocardial infarction after orthopaedic surgery and examines how myocardial injury is detected, with particular emphasis on the role of troponin testing.

SUBJECTS

Eight recent orthopaedic trials evaluating the use of troponin were identified in the literature and included in this review.

RESULTS

This review found that the diagnosis of myocardial infarction ismore difficult after surgery since classic symptoms may be atypical or absent. Therefore, there ismore reliance on the typical rise and fall in troponin to diagnose cardiac injury especially because electrocardiograph changes may be hard to detect. The pathophysiology of ischaemia after orthopaedic surgery may be different to ischaemia in the non-surgical setting. The incidence of troponin elevation is between 22 and 52.9% after emergency orthopaedic operations. Of note, patients sustaining a troponin elevation are often asymptomatic. Small studies have found troponin to be a prognostic marker of in-hospital cardiac complications, increased length of stay, increased likelihood of discharge to residential care and death at 1 year. No interventional studies have been published to date.

CONCLUSION

Cardiac injury is an important complication after orthopaedic surgery. Studies have found that troponin testing can detect asymptomatic cardiac injury. These patients are at risk of poorer outcomes and future research should be directed towards treatment of these patients.

Revised cardiac risk index and postoperative morbidity after elective orthopaedic surgery: a prospective cohort study

BACKGROUND

The revised cardiac risk index (RCRI) is associated strongly with increased cardiac ischaemic risk and perioperative death. Associations with non-cardiac morbidity in non-cardiac surgery have not been explored. In the elective orthopaedic surgical population, morbidity is common but preoperative predictors are unclear. We hypothesized that RCRI would identify individuals at increased risk of non-cardiac morbidity in this surgically homogenous population.

METHODS

Five hundred and sixty patients undergoing elective primary (>90%) and revision hip and knee procedures were studied. A modified RCRI (mRCRI) score was calculated, weighting intermediate and low risk factors. The primary endpoint was the development of morbidity, collected prospectively using the Postoperative Morbidity Survey, on postoperative day (POD) 5.

RESULTS

Morbidity on POD 5 was more frequent in patients with mRCRI ≥ 3 {relative risk 1.7, [95% confidence interval (CI): 1.4-2.1]; P<0.001}. Time to hospital discharge was delayed in patients with mRCRI score ≥ 3 (log-rank test, P=0.0002). Pulmonary (P<0.001), infectious (P=0.001), cardiovascular (P=0.0003), renal (P<0.0001), wound (P=0.02), and neurological (P=0.002) morbidities were more common in patients with mRCRI score ≥ 3. Pre/postoperative haematocrit, anaesthetic/analgesic technique, and postoperative temperature were similar across mRCRI groups. There were significant associations with hospital stay, as measured by the area under the receiver-operating characteristic curves for mRCRI 0.64 (95% CI: 0.58-0.70) and POSSUM 0.70 (95% CI: 0.63-0.75).

CONCLUSIONS

mRCRI score ≥ 3 is associated with increased postoperative non-cardiac morbidity and prolonged hospital stay after elective orthopaedic procedures. mRCRI can contribute to objective risk stratification of postoperative morbidity.

Perioperative management of the patient with cardiac disease

The overall incidence of perioperative death is relatively low. However, patients with coronary artery disease are at higher than average risk of perioperative cardiac complications. Thus, preoperative testing for cardiac disease should be done in certain patients in an effort to reduce postoperative mortality and morbidity. Patients who require emergent orthopaedic surgery are at greater risk of perioperative cardiac events than are those who undergo elective procedures. Certain modalities, such as beta blockers, statins, and alpha-2 agonists, may be started or continued in the postoperative period to further enhance cardiac function. We review the current recommendations for preoperative cardiac testing in orthopaedic patients and for perioperative management of orthopaedic patients with known cardiac disease.

The relationship between skeletal muscle serum markers and primary THA: a pilot study

Various reports confirm elevations in serum markers associated with skeletal muscle injury after orthopaedic surgery in the absence of overt clinical manifestations of myocardial injury. We therefore measured the influence surgical approach has on these serum markers after primary THA. We nonrandomly enrolled 30 nonconsecutive patients undergoing THA in three groups of 10 based on current surgical approaches used at our facility: (1) minimally invasive (MIS) modified Watson Jones approach; (2) miniposterior transmuscular approach (MIS-I); and (3) MIS-II incision. Blood samples for hemoglobin, hematocrit, cardiac troponin I, total creatine kinase, creatine phosphokinase, and serum myoglobin were obtained the morning before surgery as a baseline, immediately postoperatively, and 72 hours thereafter. We found reproducible trends in serum enzyme levels consistent with skeletal muscle damage resulting from primary THA. Troponin I remained normal in all but one patient indicating no myocardial contribution to measured serum enzyme levels. All three procedures resulted in similar trends in serum enzyme markers relevant to primary THA. Our preliminary data suggest no surgical approach appears to affect the degree of muscle trauma more or less than another.

[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.

Incidence of post-operative troponin I rises and 1-year mortality after emergency orthopaedic surgery in older patients

OBJECTIVES

to determine the incidence of post-operative troponin I rises and its association with 1-year all-cause mortality and cardiac events after emergency orthopaedic-geriatric surgery, which has not been studied before.

METHODS

one hundred and two patients over the age of 60 were recruited and followed up at 1 year. All consented to serial troponin I measurements peri-operatively.

RESULTS

the incidence of a troponin I rise post-operatively was 52.9%. Post-operative acute myocardial infarction was diagnosed in 9.8% and at 1 year, 70% of these patients were dead. At 1 year, 32.4% (33/102) had sustained a cardiac event (myocardial infarction, congestive cardiac failure, atrial fibrillation or major arrhythmia) and using multivariate analysis, post-operative troponin rise (OR 3.9, 95% CI 1.4-10.7, P = 0.008) was an independent predictor of this. Half of the patients with a troponin rise had a cardiac event compared to 18.8% without a rise. All-cause mortality was 20.6% at 1 year; 37% with an associated post-operative troponin rise died versus 2.1% without a rise (P < 0.0001). Using multivariate analysis, only two factors were associated with 1-year all-cause mortality: post-operative troponin rise (OR 12.0, 95% CI 1.4-104.8, P = 0.025) and sustaining a post-operative in-hospital cardiac event (OR 6.6, 95% CI 1.7-25.6, P = 0.006). Furthermore, patients with higher troponin levels had significantly worse survival.

CONCLUSIONS

there is a high incidence of post-operative troponin I rises in older patients undergoing emergency orthopaedic surgery with 1-year mortality and cardiac events being significantly increased in these patients. Future studies are needed to determine whether any intervention can improve outcome for these patients.

Troponin T as a predictive marker of morbidity in patients with fractured neck of femur

INTRODUCTION

This study aims prospectively to assess perioperative measurement of Troponin T, a marker of myocardial injury, as a predictor of morbidity and mortality in patients undergoing surgery for fractured neck of femur.

METHOD

All patients aged 65 years and over presenting with a fractured neck of femur over a 4-month period were initially included. Exclusion criteria were renal failure, polymyositis and conservative fracture management. Troponin T levels were measured on admission, day 1 and 2 post-surgery. According to local protocol, a level of >0.03 ng/mL was considered to be raised. Adverse outcome measures were cardiorespiratory events (myocardial infarction, congestive cardiac failure, unstable angina, major arrhythmias requiring treatment and pulmonary embolism), death and length of inpatient stay.

RESULTS

One hundred and twenty-nine patients presented with femoral neck fractures. 108 patients were included after application of the exclusion criteria. 42 (39%) showed a Troponin rise. Of these, 25 sustained one or more outcome complications versus seven with no rise (p<0.001). The mean hospital stay was 25.7 days for patients with elevated Troponin, 18.3 days in the normal group (p<0.012). There were nine deaths in the raised Troponin group, and five with no rise (p<0.05).

DISCUSSION

The principle causes of early death after hip fracture surgery are cardiac failure and myocardial infarction. Troponin T is a sensitive enzymatic marker of myocardial injury. The association between raised Troponin and hip fractures has not previously been made. In our series, 39% showed a perioperative Troponin rise. This was significantly associated with increased morbidity, mortality and longer hospitalisation. Many patients appear to be having silent events, causing significant morbidity. We recommend Troponin measurement in all patients to identify this risk and allow appropriate optimisation measures.

The one year incidence of postoperative myocardial infarction in an orthopedic population

The diagnosis of a postoperative myocardial infarction (PMI) is important in the orthopedic population because these events can be associated with significant cardiac morbidity. Plasma troponin I (cTnI) analysis has markedly increased our ability to detect myocardial damage. Using cTnI analysis for evidence of a PMI, we prospectively assessed all of our patients for (1) the 1-year incidence of PMI, (2) the clinical consequences of a PMI in relation to the level of the cTnI release, and (3) 6-month follow-up for cardiac complications. During a 12-month period, patients at risk for perioperative myocardial ischemia were assessed for a PMI by serum cTnI levels and daily serial ECGs. Patients with cTnI levels above the reference level (> or = 0.4 ng/ml) were also assessed for new cardiac regional wall motion abnormalities with an echocardiogram and 6-month postdischarge adverse cardiac events. Of the 758 patients who were assessed for a PMI, 49 patients had detectable cTnI levels (> or = 0.4 ng/ml); the incidence of a PMI was 0.6% of all surgical cases and 6.5% of those patients were at risk for a cardiac event. A PMI was more common after hip arthroplasty than other orthopedic procedures. Twenty-three patients had a cTnI level >3.0 ng/ml, and 74% these patients (17/23) had anginal symptoms and/or ischemic ECG changes. Nine of these patients (9/23) had new postoperative echocardiographic changes, five (5/23) required emergency transfer to a cardiac care unit, and 10 (10/23) had postoperative cardiac complications. In contrast, 15 patients with levels of cTnI <3.0 ng/ml and without ischemic ECG changes and/or anginal symptoms had no postoperative cardiac complications. Fourteen patients (14/47) had cardiac complications 6 months after discharge, including four cardiac deaths, one fatal stroke, and four patients with unstable anginal episodes that required a change in medical management, and six patients required coronary revascularization. Orthopedic surgical patients with cTnI level <3 ng/ml and without symptoms or ECG changes suggestive of myocardial ischemia (15/49) may have different risks than those with higher-level cTn1.

Pre-operative high sensitivity C-reactive protein and postoperative outcome in patients undergoing elective orthopaedic surgery

High-sensitivity C-reactive protein (hsCRP) adds important prognostic information, not reflected by traditional risk factors, to the prediction of both the development and outcome of cardiovascular pathology. HsCRP levels also correlate inversely with cardiorespiratory fitness, an important determinant of peri-operative outcome. We hypothesised that pre-operative hsCRP should be associated with excess peri-operative morbidity and longer length of stay. Pre-operative hsCRP was measured blinded to standardised postoperative outcomes in 129 elective orthopaedic patients. HsCRP levels were divided into high (> 3 mg x l(-1)) or low (< 3 mg x l(-1)) groups (Center for Disease Control stratification). High-CRP patients had significant cardiovascular history, received cardiac medication or steroid therapy (p < 0.05). Higher pre-operative hsCRP was associated with longer length of stay: mean 7.5 days (95% CI: 6.2-8.8) vs 6.0 days (95% CI: 5.5-6.5; p = 0.03; log rank test). In 21 patients with > 8 days length of stay, high pre-operative hsCRP patients were over-represented (p = 0.04). Pre-operative hsCRP is related to length of stay and delayed postoperative complications.

Perioperative creatine phosphokinase (CPK) and troponin I trends after elective hip surgery

BACKGROUND

Perioperative myocardial infarction (MI) is an important risk factor for cardiac morbidity and mortality after hip surgery. On the basis of the limitations of creatine kinase cardiac muscle isoenzyme (CK-MB) in the perioperative setting, and the high specificity of troponin I, we hypothesized that troponin I would be effective at detecting perioperative MI more frequently than CK-MB would be, after hip surgery.

METHODS

A prospective study of the serum levels of creatine phosphokinase (CPK), its isoenzyme CK-MB, and troponin I, in 90 patients with risk factors for coronary artery disease, undergoing hip surgery is reported. We measured these cardiac markers in the postoperative period for 5 days, after hemiarthroplasty, total hip arthroplasty, and hip intramedullary nailing.

RESULTS

We found increased levels of creatine phosphokinase and CK-MB, after all the types of operation, with maximum levels reached on the first postoperative day and the levels were more pronounced after total hip arthroplasty. False-elevated CK-MB index >6% without MI was evidenced in 43.3% of patients. Troponin I levels were elevated >3.1 ng/mL only in the patients who suffered MI postoperatively. All the patients who suffered MI had both CK-MB index and troponin I levels elevated. Also, we found high correlation between maximum CK-MB levels and size of implants, which means that reaming and its heating effect may be responsible for false-elevated CK-MB levels, except direct muscle damage caused by surgical incision.

CONCLUSION

CK-MB index and troponin I have the same sensitivity, but troponin I is more specific than CK-MB index in detecting MI after hip surgery.

Cardiac troponin I release after hip surgery correlates with poor long-term cardiac outcome

BACKGROUND AND OBJECTIVE

The aim of this study was to assess the incidence of perioperative myocardial damage detected by serial measurements of troponin I after hip surgery and its association with late cardiovascular outcome.

METHODS

Troponin I was measured during the first three postoperative days in 88 consecutive patients undergoing hip surgery. Values above the 99th percentile (0.08 ng mL(-1)) were considered positive. Major cardiac events (cardiac death, myocardial infarction and cardiac failure) were recorded during hospital stay and 1 yr after surgery.

RESULTS

Eleven patients (12.5%) exhibited elevated troponin I levels during hospital stay. Nine of them remained asymptomatic. During follow-up, 45% of them (5/11) suffered from a major cardiac event vs. 4% (3/76) for patients with normal postoperative troponin I levels (P = 0.0006). All-cause mortality rate was 36% (4/11) at 1 yr vs. 7% (5/71, P = 0.0131). Using multivariate Cox regression analysis adjusted for baseline data, independent factors associated with the occurrence of a cardiac event were troponin I elevation (OR=17.4-CI 95% 3.7-82) and age (OR=1.1 yr(-1)-CI 95% 1.01-1.21). Independent factors for all-cause mortality were troponin I elevation (OR=41.4-CI 95% 5.4-320.4), and age (OR=1.3 yr(-1)-CI 95% 1.1-1.4).

CONCLUSION

Troponin I release is common after hip surgery and is associated with a 10-fold increased incidence of long-term major cardiac events as compared to patients with normal troponin I levels (45% vs. 4%).

Critical care issues in the patient after major joint replacement

Admission rates of orthopedic patients to intensive care units are increasing. Thus, an intensivist's familiarity with specific problems associated with major joint replacement surgery is of utmost importance in order to meet the needs of this particular patient population. In this article, the authors review the most commonly encountered complications after major hip and knee arthroplasty. Perioperative risk factors for morbidity and mortality and the epidemiology, diagnosis, and treatment of cardiopulmonary complications in this patient population are discussed. Procedure-specific complications such as fat embolism and acrylic bone cement-related issues are reviewed.

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.

Evaluation of cardiac involvement following major orthopedic surgery

BACKGROUND

Cardiovascular morbidity is frequent after non-cardiac surgery and the early recognition of cardiac involvement is an essential tool for clinical risk stratification and management. The aim of this study was to investigate the behavior of traditional and emerging cardiac markers, including NT-prohormone-brain natriuretic peptide (NT-proBNP) and ischemia-modified albumin (IMA), in the perioperative period in patients undergoing major uncomplicated orthopedic surgery.

METHODS

A total of 37 patients undergoing major orthopedic surgery were longitudinally evaluated for NT-proBNP, IMA, cardiac troponin T (cTnT), creatine kinase isoenzyme MB and myoglobin 3 h before surgery and 4 and 72 h thereafter.

RESULTS

NT-proBNP values were significantly increased at 72 h postoperative compared to both 3 h preoperative and 4 h postoperative (NT-proBNP: 20 vs. 4.5 pmol/L, p<0.001 and 20 vs. 5.9 pmol/L, p<0.001). IMA levels were significantly increased at 4 and 72 h postoperative vs. 3 h preoperative (132 vs. 113 kU/L, p=0.02 and 151 vs. 113 kU/L, p<0.001). In a stepwise regression model, the perioperative liquid amount and degree of modification in postoperative creatinine levels (delta-creatinine) were independently related to the NT-proBNP increase.

CONCLUSIONS

The significant increase observed in NT-proBNP suggests that patients undergoing major uncomplicated orthopedic surgery may develop subclinical cardiac stress, presumably attributable to the considerable infusion of liquids. The clinical significance of this finding deserves further investigation, especially in patients at higher risk of heart failure.

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.

Dosage des isoformes cardiaques des troponines T ou I : intérêt en cardiologie et en anesthésie–réanimation

Measurement of cardiac troponin I or T in serum (highly specific for the myocardium) have replaced classical markers, such as creatine kinase MB. Cardiac troponins are preferred markers because of their high specificity and sensitivity. This had led to modifications of the original World Health Organization criteria for acute myocardial infarction. Furthermore, the place of the troponins as superior markers of subsequent cardiac risk in acute coronary syndrome has now become firmly established, for both diagnostic and risk stratification purposes. The use of C-reactive protein and/or other inflammatory biomarkers may add independent information in this context. After non cardiac surgery, the total cardiospecificity of cardiac troponins explains why other biomarkers of necrosis should no longer be used. Recent studies suggest that any elevation of troponin in the postoperative period is indicative of increased risk of long-term cardiac complications. This prognostic value has been previously demonstrated in other clinical settings such as invasive coronary intervention (surgical myocardial revascularization and percutaneous coronary intervention) and after heart valve surgery. Increases of troponin indicate cardiac damage, whatever the mechanism (ischemic or not). Other causes of cardiac injury include: pulmonary embolism, myocarditis, pericarditis, congestive heart failure, septic shock, myocardial contusion. In most cases, elevation of troponins has been shown to be associated with a bad outcome.

Myocardial infarction in major noncardiac surgery: Epidemiology, pathophysiology and prevention

The number of subjects undergoing major noncardiac surgery who are at risk for perioperative myocardial infarction (MI) is growing worldwide.

It has been estimated that 500,000 to 900,000 patients suffer major perioperative cardiovascular complications every year, with consequent heavy, long-term prognostic implications and costs.

It is well known that perioperative MIs don’t share the same pathophysiology as nonsurgical MIs but the relative role of the different, potential triggers has not been completely clarified.

Many aspects of the perioperative management, including risk-stratification and prophylactic or postoperative interventions have also not been completely defined.

Throughout recent years many resources have been invested to clarify these aspects and experts have developed indices and algorithm-based strategies to better assess the cardiac risk and to guide the perioperative management.

The scope of the present review is to discuss the main aspects of perioperative MI in noncardiac surgery, with particular regard to epidemiology, pathophysiology, preoperative risk stratification, prophylaxis and therapy.

Medical complications of surgical treatment of adult spinal deformity and how to avoid them

STUDY DESIGN

Review article of medical complications related to adult spinal deformity surgery.

OBJECTIVE

To identify medical complications related to surgery for adult spinal deformity and suggest ways to minimize their occurrence and to avoid them.

SUMMARY OF BACKGROUND DATA

Medical complications are a major consideration in adult spinal deformity surgery. Few studies have been done to identify the medical complication rate in relation to these procedures.

METHODS

We review the literature pertaining to medical complications regarding spinal deformity surgery.

RESULTS

Urinary tract infections are the most frequently seen complication. Additionally, pulmonary complications are the most common life-threatening complication. Medical complications are a frequent occurrence with adult deformity spinal surgery.

CONCLUSIONS

Awareness of the presentation, treatment, and prevention of medical complications of deformity surgery may allow minimization of their occurrence and optimize treatment should they occur.

Incidence and timing of myocardial infarction after total joint arthroplasty

Retrospective review of 3471 patients who underwent total joint arthroplasty (TJA) (1479 hips, 1992 knees) to determine the incidence and timing of inhospital myocardial infarction (MI) after TJA. Sixty-three patients (1.8%; 95% CI, 1.4%-2.4%) suffered a perioperative MI occurring at a mean of 3 days post surgery. In multivariate analysis, increased age, body mass index, bilateral TJA, diabetes, and American Society of Anesthesiologists rating 3 were associated with perioperative MI. Our data cautions against hospital discharge within 3 days of surgery.

Surveillance and prevention of major perioperative ischemic cardiac events in patients undergoing noncardiac surgery: a review

This is the second of 2 articles evaluating cardiac events in patients undergoing noncardiac surgery. Unrecognized myocardial infarctions (MIs) are common, and up to 50% of perioperative MIs may go unrecognized if physicians rely only on clinical signs or symptoms. In this article, we summarize the evidence regarding monitoring strategies for perioperative MI in patients undergoing noncardiac surgery. Perioperative troponin measurements and 12-lead electrocardiograms can detect clinically silent MIs and provide independent prognostic information. Currently, there are no standard diagnostic criteria for perioperative MIs in patients undergoing noncardiac surgery. We propose diagnostic criteria that reflect the unique features of perioperative MIs. Finally, we review the evidence for perioperative prophylactic cardiac interventions. There is encouraging evidence that some perioperative interventions (e.g., beta-blockers, alpha2-adrenergic agonists, statins) may prevent major cardiac ischemic events, but firm conclusions await the results of large definitive trials. The best evidence does not support a management strategy of preoperative coronary revascularization before noncardiac surgery.

QTc dispersion is prolonged in patients with early postoperative adverse cardiovascular events and those with silent myocardial ischemia

OBJECTIVE

To determine if increased QT interval dispersion (corrected and not corrected for heart rate) is associated with perioperative silent myocardial ischemia or postoperative adverse cardiovascular events.

DESIGN

Blinded retrospective observational study.

SETTING

University hospital.

PARTICIPANTS

One hundred eighty-one perioperative patients receiving general anesthesia for elective major vascular or orthopedic surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

QT dispersion, corrected and uncorrected for heart rate, was prolonged in patients suffering significant myocardial ischemia up to 48 hours assessed by Holter ECG monitoring, for early cardiac morbidity and all early cardiac events (including mortality) up to 1 month postoperatively. There were no significant changes in patients showing early cardiovascular mortality or late cardiac morbidity or mortality between 1 and 12 months postoperatively. Morbidity and mortality were determined from clinical notes, laboratory investigations, and autopsy when available. QT dispersion performed poorly as a screening test to identify those who subsequently developed early adverse cardiovascular outcomes.

CONCLUSIONS

QT dispersion is prolonged in those at risk of early adverse cardiovascular events but is a poor screening tool.

Peri-operative troponin I concentration as a marker of long-term postoperative adverse cardiac outcomes ? A study in high-risk surgical patients

We have previously demonstrated that the peri-operative measurement of increased serum concentrations of the cardiac markers troponins I and T and creatine kinase-MB can be predictors of major cardiovascular outcomes (including cardiac death) at 3 months after surgery. In the present study, we have followed the postoperative course of 157 patients undergoing major vascular surgery or major joint arthroplasty to 1 year using a patient questionnaire, general practitioner follow-up and case-notes review. Increased postoperative marker concentrations were defined as values greater than the upper reference limit. Increases in troponin I and troponin T concentrations, as well as a single elevated creatine kinase-MB and two successively elevated creatine kinase-MB concentrations were measured in 12, 13, 33 and 15 patients respectively. Thirty-nine major adverse cardiac outcomes were recorded (cardiac death, myocardial ischaemia, congestive cardiac failure, unstable angina, cerebrovascular accident and major arrhythmias needing active treatment). There was no association between increases in any of these cardiac markers and cardiac death to 1 year. However, increases in troponin I and both a single elevated creatine kinase-MB and two successively elevated creatine kinase-MB concentrations were associated with an increased incidence of major cardiac outcomes, including cardiac death, to 1 year (odds ratio [95% confidence intervals] = 4.19 [1.16-14.87], 3.97 [1.65-9.44] and 5.19 [1.60-16.22], respectively).

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.