Perioperative ischemia and cardiac complications in major vascular surgery: importance of the preoperative twelve-lead electrocardiogram

Preoperative electrocardiogram in prediction of 90-day postoperative mortality: retrospective cohort study

BACKGROUND

There are conflicting data on the relationship between preoperative electrocardiogram and postoperative mortality. We aimed to assess the predictive value of preoperative ECG on postoperative all-cause mortality in patients undergoing non-cardiac surgery (NCS).

METHODS

We retrospectively reviewed records of hospitalized patients who underwent an internal preoperative examination and subsequent NCS in the years 2015-2021. We recorded patient comorbidities, vital functions, results of biochemical tests, ECG. The primary end point was 90-day postoperative all-cause mortality, acquired from the hospital records and the nationwide registry run by the Institute of Health Information and Statistics of the Czech Republic.

RESULTS

We enrolled a total of 2219 patients of mean age 63 years (48% women). Of these, 152 (6.8%) died during the 90-day postoperative period. There were statistically significant associations between increased 90-day postoperative all-cause mortality and abnormal ECG findings in resting heart rate (≥ 80 bpm, relative risk [RR] = 1.82 and ≥ 100 bpm, RR = 2.57), presence of atrial fibrillation (RR = 4.51), intraventricular conduction delay (QRS > 0.12 s, RR = 2.57), ST segment changes and T wave alterations, left bundle branch hemiblock (RR = 1.64), and right (RR = 2.04) and left bundle branch block (RR = 4.13), but not abnormal PQ and QT intervals, paced rhythm, incomplete right bundle branch block, or other ECG abnormalities. A resting heart rate (≥ 80 bpm, relative risk [RR] = 1.95 and ≥ 100 bpm, RR = 2.20), atrial fibrillation (RR = 2.10), and right bundle branch block (RR = 2.52) were significantly associated with 90-day postoperative all-cause mortality even in subgroup of patients with pre-existing cardiac comorbidities.

CONCLUSIONS

Patients with abnormal preoperative ECG findings face an elevated risk of all-cause mortality within 90 days after surgery. The highest mortality risk is observed in patients with atrial fibrillation and left bundle branch block. Additionally, an elevated heart rate, right bundle branch block, and atrial fibrillation further increase the risk of death in patients with pre-existing cardiac conditions.

Perioperative outcomes following preoperative epidural analgesia in hip fracture patients undergoing surgical repair: A systematic review

OBJECTIVE

To examine the effectiveness and safety of epidural analgesia in the presurgical period on hip fracture patients undergoing surgical repair.

DESIGN

Systematic review.

METHODS

The study protocol was registered with the PROSPERO systematic reviews register: CRD42019140396. Electronic databases were searched for randomized controlled trials comparing preoperative epidural analgesia to other forms of pain management in hip fracture patients. The primary outcomes included perioperative cardiac events and mortality. Pain, non-cardiac complications, and adverse effects were also examined as secondary outcomes. Heterogeneity of the included studies was assessed using the I2 statistic and a random-effects meta-analysis was conducted once sufficient homogeneity was demonstrated.

RESULTS

Four studies met the inclusion criteria, which included a total of 221 patients. Preoperative epidural analgesia resulted in fewer cardiac events, which was a reported outcome in two included studies (RR 0.30; 95% CI 0.14-0.63; I2 = 0%). Preoperative epidural analgesia was also associated with decreased perioperative mortality in a meta-analysis of two studies (RR 0.13; 95% CI 0.02-0.98; I2 = 0%). Pain was not pooled due to variability in assessment methods, but preoperative epidural analgesia was associated with reduced pain in all four studies.

CONCLUSIONS

Preoperative epidural analgesia for hip fracture may reduce perioperative cardiac events and mortality, but the number of included studies in this systematic review was low. More research should be done to determine the benefit of early epidural analgesia for hip fractured patients.

ECG changes after non-cardiac surgery: a prospective observational study in intermediate-high risk patients

BACKGROUND

Efforts to mitigate the risk for perioperative cardiac events focus on both patient's and operation's risk and often include a preprocedural electrocardiogram (ECG). The merits of postprocedural ECG for detection of occult cardiac events occurring during surgery are unknown. We aim to explore the incidence of pre, and new postprocedural ECG pathologies in an intermediate-high risk population undergoing non-cardiac surgery.

METHODS

This single-center, prospective, observational study, included patients older than 18 years with at least two cardiovascular risk factors who were scheduled for non-cardiac surgery. All patients had pre, and postprocedural ECG. The ECG was analyzed and coded according to the Minnesota criteria. A multivariable logistic regression analysis was performed for indices associated with new postoperative ECG pathologies.

RESULTS

A total of 217 patients were enrolled. Preoperative pathologic ECG changes were recorded in 62.2% of the patients. Postoperatively, new ECG pathologies were documented in 49.8% of patients, most commonly T-wave changes (36.4% of changes). Pathologic ECG changes at baseline (OR 3.15, 95% CI [1.61-6.17]; P<0.01), diabetes (OR 1.93, 95% CI [1.02-3.64]; P=0.04), history of ischemic heart disease (OR 2.14, 95% CI [1.03-4.47]; P=0.04), higher volumes of fluid replacement (OR 1.70, 95% CI [1.10-2.61]; P=0.01) and higher levels of preoperative hemoglobin (OR 1.24, 95% CI [1.04-1.47]; P=0.01) were all independently associated with postoperative ECG changes.

CONCLUSIONS

Pre-, but most importantly, postoperative ECG changes are common in intermediate-high risk surgical patients. Postoperative ECG may be valuable to disclose silent cardiovascular events that occurred during surgery.

Perioperative Cardiovascular Risk Assessment and Management for Noncardiac Surgery: A Review

IMPORTANCE

Perioperative cardiovascular complications occur in 3% of hospitalizations for noncardiac surgery in the US. This review summarizes evidence regarding cardiovascular risk assessment prior to noncardiac surgery.

OBSERVATIONS

Preoperative cardiovascular risk assessment requires a focused history and physical examination to identify signs and symptoms of ischemic heart disease, heart failure, and severe valvular disease. Risk calculators, such as the Revised Cardiac Risk Index, identify individuals with low risk (<1%) and higher risk (≥1%) for perioperative major adverse cardiovascular events during the surgical hospital admission or within 30 days of surgery. Cardiovascular testing is rarely indicated in patients at low risk for major adverse cardiovascular events. Stress testing may be considered in patients at higher risk (determined by the inability to climb ≥2 flights of stairs, which is <4 metabolic equivalent tasks) if the results from the testing would change the perioperative medical, anesthesia, or surgical approaches. Routine coronary revascularization does not reduce perioperative risk and should not be performed without specific indications independent of planned surgery. Routine perioperative use of low-dose aspirin (100 mg/d) does not decrease cardiovascular events but does increase surgical bleeding. Statins are associated with fewer postoperative cardiovascular complications and lower mortality (1.8% vs 2.3% without statin use; P < .001) in observational studies, and should be considered preoperatively in patients with atherosclerotic cardiovascular disease undergoing vascular surgery. High-dose β-blockers (eg, 100 mg of metoprolol succinate) administered 2 to 4 hours prior to surgery are associated with a higher risk of stroke (1.0% vs 0.5% without β-blocker use; P = .005) and mortality (3.1% vs 2.3% without β-blocker use; P = .03) and should not be routinely used. There is a greater risk of perioperative myocardial infarction and major adverse cardiovascular events in adults aged 75 years or older (9.5% vs 4.8% for younger adults; P < .001) and in patients with coronary stents (8.9% vs 1.5% for those without stents; P < .001) and these patients warrant careful preoperative consideration.

CONCLUSIONS AND RELEVANCE

Comprehensive history, physical examination, and assessment of functional capacity during daily life should be performed prior to noncardiac surgery to assess cardiovascular risk. Cardiovascular testing is rarely indicated in patients with a low risk of major adverse cardiovascular events, but may be useful in patients with poor functional capacity (<4 metabolic equivalent tasks) undergoing high-risk surgery if test results would change therapy independent of the planned surgery. Perioperative medical therapy should be prescribed based on patient-specific risk.

New Q Waves and T-Wave Inversions Following Endovascular Surgery Lead to Diagnosis of Clinically Silent Myocardial Infarction Despite Negative Preoperative Cardiovascular Risk Evaluation: A Case Report

In this case, a 79-year-old male presented with new anteroseptal Q waves and T-wave inversions across the precordial leads following an otherwise uneventful endovascular repair of his thoracoabdominal aortic aneurysm. The patient had no history of cardiac disease and had undergone a dobutamine stress echocardiogram within the preceding 6 months that showed no evidence of inducible ischemia. Nevertheless, routine postoperative electrocardiogram (EKG) revealed new Q waves and T-wave inversions and transthoracic echocardiogram that demonstrated akinesis of the left ventricle (LV) apex with chronic-appearing apical thrombus. We will further discuss preoperative evaluation of cardiovascular risk along with postoperative interpretation of EKG abnormalities.

Electrocardiographic and echocardiographic features in patients with major arterial vascular disease assigned to surgical revascularization

Background: We aimed to depict the electrocardiographic and echocardiographic aspects in patients before elective major vascular surgery.Methods: We evaluated through standard 12 lead electrocardiography and transthoracic echocardiography 469 patients with asymptomatic large abdominal aortic aneurysm (AAA), 334 with critical carotid stenosis (CAS), and 238 with advanced peripheral artery disease (PAD) before surgical revascularization.Results: Patients with AAA were predominantly males (p < .001) with normal sinus rhythm (p = .026), were more affected by atrioventricular block (p = .033) and left anterior fascicular block (p < .001). They also presented larger aortic root size (p < .001) and septal hypertrophy (p = .036), in addition, atrial fibrillation was less frequent in the same group (p = .023). Patients with CAS were of older age (p < .001) with a substantial number of females (p < .001). They presented less left ventricular segmental kinetic disorders and fewer dilated ventricles (p = .004 and p < .001 respectively). Finally, those with PAD had reduced septal and posterior wall thickness (p < .01, p = .009 respectively), greater mitral and aortic annular calcification (p < .001), and were more affected by previous myocardial infarction (p < .001). The PR interval, left anterior fascicular block and aortic root size were independently associated with aneurysm, previous myocardial infarction with PAD, while smaller left ventricular end systolic volumes with carotid artery stenosis.Conclusions: Patients with AAA were mostly affected by cardiac conduction disorders, septal hypertrophy, aortic root dilation and less affected by atrial fibrillation. Patients with CAS were older with more normal sized ventricles, whereas, previous myocardial infarction was most common amongst patients with peripheral artery disease.

Diagnosing Perioperative Myocardial Infarction in Cardioth oracic and Vascular Surgery

Patients undergoing cardiac and high-risk noncardiac surgery have a high incidence of perioperative myocardial infarction. The early diagnosis of perioperative myocardial injury in these patients is complicated. In the perioperative period, there is a high incidence of nonspecific electrocardiographic changes and cardiac biomarker release. It is becoming increasingly imortant to differentiate myocardial necrosis from nonspecific changes because of the need for early intervention and the poential long term implications of a perioperative myocardial event. Although sensitive and specific assays to assess myoardial damage have been developed, specific thresholds to establish the occurrence a significant perioperative event have not been firmly defined. This review will attempt to outline the current evidence supporting the use of clinical symptoms, electrocardiographic changes, and cardiac biomarkers in the diagnosis of perioperative myocardial infarction and the longerm implication of these findings.

The Preoperative Evaluation of the Patient With Cardiac Risk Factors for Noncardiac Surgery: Which Patients Need Further Cardiac Risk Stratification Tests?

Cardiac risk stratification tests should be pursued only in the subgroup of patients who have a moderate to high incidence of significant coronary artery disease and only in those who will gain long-term benefit from coronary revascularization if they are found to have significant coronary artery disease. Furthermore, car diac risk stratification tests should be pursued only if the perioperative mortality and morbidity from com bined coronary revascularization followed by noncar diac surgery is not significantly higher than proceeding straight to noncardiac surgery alone. Indentification of the subgroup of patients who will need cardiac strati fication tests should be based on integration of the patient's cardiac risk factors and functional capacity with the risk and stress of the particular surgery.

Chronic Antiplatelet Use Associated With Increased Blood Loss in Lumbar Spinal Surgery Despite Adherence to Protocols

There are conflicting reports regarding postoperative bleeding risks associated with discontinuation of antiplatelet therapy at least 7 days preoperatively. Most of the studies in the spine literature are based on surveys or anecdotal evidence. The majority of surgeons discontinue therapy 7 days preoperatively, but this varies widely from 5 to 21 days. The purpose of this retrospective study was to assess whether chronic antiplatelet use is associated with increased intraoperative blood loss, need for transfusion, and perioperative complications. Of 454 patients who underwent elective lumbar spinal surgery, 85 were on antiplatelet therapy and 369 were not. All patients stopped antiplatelet therapy at least 7 days preoperatively with approval from their cardiologist or primary care provider. Multiple regression analysis was performed and corrected for age, sex, antiplatelet therapy, number of levels decompressed/fused/instrumented, preoperative hematocrit, and postoperative hematocrit. Results showed that preoperative antiplatelet therapy, despite at least 7 days of discontinuation, is a statistically significant predictor (P=.04) of increased intraoperative blood loss. Blood transfusion was not associated with antiplatelet use but was associated with the number of levels fused, age, and low preoperative hematocrit (all P<.01). There were no recorded complications in either group. The authors conclude that antiplatelet therapy is associated with an increased risk of intraoperative blood loss in spine patients despite discontinuation at least 7 days preoperatively, but the clinical significance of this is unclear given the lack of association with blood transfusions and perioperative complications. [Orthopedics. 2016; 39(4):e695-e700.].

Review of a Large Clinical Series: Perioperative Myocardial Infarction in Low-Risk Patients Undergoing Noncardiac Surgery Is Associated With Intraoperative Hypotension

This is an investigation of the association of intraoperative hypotension and perioperative myocardial infarction (MI) in low-risk patients undergoing noncardiac surgery. The case-control study compared all patients who experienced perioperative MI during the years 1996 through 1999 to a similar group of patients matched for multiple variables. Perioperative MI occurred in 22 patients. Two patients, who underwent unusual surgical procedures, were excluded from the study. The remaining 20 MI patients were compared with 40 patients who had the same types of surgery and similar mean ages, co-morbidities and preoperative evaluations. Of the patients suffering a perioperative MI, 14 (70%) experienced intraoperative hypotension, as opposed to 11 (28%) of those who did not have an MI ( P = .002). Six (30%) MI patients died as opposed to only one (2.5%) of the non-MI group ( P = .004). When subjected to logistic regression analysis, intraoperative hypotension remained the only significant variable associated with perioperative MI ( P = .0056). Intraoperative hypotension is associated with an increased risk of perioperative myocardial infarction and death.

Cardiac Risk Assessment, Morbidity Prediction, and Outcome in the Vascular Intensive Care Unit

Objectives:

The aim of this study is to examine the predictive value of the Lee revised cardiac risk index (RCRI) for a standard vascular intensive care unit (ICU) population as well as assessing the utility of transthoracic echocardiography and the impact of prior coronary artery disease (CAD) and coronary revascularization on patient outcome.

Design:

This is a retrospective review of prospectively maintained Vascubase and prospectively collected ICU data.

Materials and Methods:

Data from 363 consecutive vascular ICU admissions were collected. Findings were used to calculate the RCRI, which was then correlated with patient outcomes. All patients were on optimal medical therapy (OMT) in the form of cardioselective β-blocker, aspirin, statin, and folic acid.

Results:

There was no relationship found between a reduced ejection fraction and patient outcome. Mortality was significantly increased for patients with left ventricular hypertrophy (LVH) as identified on echo (14.9% vs 6.5%, P = .028). The overall complication rates were significantly elevated for patients with valvular dysfunction. Discrimination for the RCRI on receiver–operating characteristic analysis was poor, with an area under the receiver–operating characteristic curve of .621. Model calibration was reasonable with an Hosmer-Lemeshow Ĉ statistic of 2.726 ( P = .256). Of those with known CAD, 41.22% of the patients receiving best medical treatment developed acute myocardial infarction (AMI) compared to 35.3% of those who previously underwent percutaneous cardiac intervention and 23.5% of those who had undergone coronary artery bypass grafting. There was 3-fold increase in major adverse clinical events in patients with troponin rise and LVH.

Conclusions:

The RCRI’s discriminatory capacity is low, and this raises difficulties in assessing cardiac risk in patients undergoing vascular intervention. The AMI is highest in the OMT group without prior cardiac intervention, which mandates protocols to identify patients requiring cardiac intervention prior to vascular procedures.

Predictive value of preoperative electrocardiography for perioperative cardiovascular outcomes in patients undergoing noncardiac, nonvascular surgery

BACKGROUND

The utility of routine preoperative electrocardiography (ECG) for assessing perioperative cardiovascular risk in patients undergoing noncardiac, nonvascular surgery (NCNVS) is unclear.

HYPOTHESIS

There would be an association between preoperative ECG and perioperative cardiovascular outcomes in patients undergoing NCNVS.

METHODS

A total of 660 patients undergoing NCNVS were prospectively evaluated. Patients age >18 years who underwent an elective, nonday case, open surgical procedure were enrolled. Troponin I concentrations and 12-lead ECG were evaluated the day before surgery, immediately after surgery, and on the first 5 postoperative days. Preoperative ECG showing atrial fibrillation, left or right bundle branch block, left ventricular hypertrophy, frequent premature ventricular complexes, pacemaker rhythm, Q-wave, ST-segment changes, or sinus tachycardia or bradycardia were classified as abnormal. The patients were followed up during hospitalization and were evaluated for the presence of perioperative cardiovascular events (PCE).

RESULTS

Eighty patients (12.1%) experienced PCE. Patients with abnormal ECG findings had a greater incidence of PCE than those with normal ECG results (16% vs 6.4%; P < 0.001). Mean QTc interval was significantly longer in the patients who had PCE (436.6 ± 31.4 vs 413.3 ± 16.7 ms; P < 0.001). Univariate analysis showed a significant association between preoperative atrial fibrillation, pacemaker rhythm, ST-segment changes, QTc prolongation, and in-hospital PCE. However, only QTc prolongation (odds ratio: 1.15, 95% confidence interval: 1.06-1.2, P < 0.001) was an independent predictor of PCE according to the multivariate analysis. Every 10-ms increase in QTc interval was related to a 13% increase for PCE.

CONCLUSIONS

Prolongation of the QTc interval on the preoperative ECG was related with PCE in patients undergoing NCNVS.

Preoperative brain natriuretic peptide (BNP) is a better predictor of adverse cardiac events compared to preoperative scoring system in patients who underwent abdominal surgery

BACKGROUND

Cardiovascular disease is the leading cause of perioperative death in surgical patients. A variety of clinical scoring systems have been developed to predict adverse cardiovascular events. B-type natriuretic peptide (BNP) is a sensitive and specific predictor of left ventricular systolic dysfunction and predicts first cardiovascular event and death in the general population. We present a prospective, single-center, observational cohort study of patients undergoing major abdominal surgery and evaluate the role of BNP in predicting adverse cardiac events.

METHOD

A total of 205 patients were included in the study. All patients were assessed by a cardiological clinical evaluation, a 12-lead ECG report, and a preoperative and postoperative blood sample for plasmatic BNP assessment. The primary end point was the predictive power of preoperative BNP levels for adverse cardiac events until 30 days after discharge.

RESULTS

Thirty-one of 205 (15%) patients had adverse cardiac events in the postoperative period up to 30 days after discharge. Five patients (2.4%) of these died of cardiac events. Preoperative BNP values were significantly increased in the 31 patients compared to the other patients in the postoperative period [mean = 112.93 pg/ml (range = 5-2,080) vs. 178.99 pg/ml (range = 5-3,980); median = 117 vs. 23 pg/ml; 95% CI = 49-181; p < 0.0001]. At logistic regression, a preoperative BNP value of >36 pg/ml was the only effective predictor of adverse cardiac events.

CONCLUSION

We have demonstrated that elevated preoperative BNP levels are independent predictors of adverse cardiac events in a cohort of patients undergoing major abdominal surgery in a general surgery department, and this is the first study about this specific cohort of patients.

Medical complications of obesity and optimization of the obese patient for colorectal surgery

Obesity is a medical epidemic with an enormous impact on disease prevalence and health care utilization. In the preoperative period, an awareness of medical issues associated with obesity is an important part of the planning for surgical procedures. The authors highlight the diagnostic and treatment options for medical conditions commonly affecting the obese patient including diabetes, hypertension, coronary artery disease, and deep venous thrombosis.

A long-term survival score improves preoperative prediction of survival following major vascular surgery

BACKGROUND

In a previous study it has been shown that a long-term survival score (LTSS), composed of Lee's Revised Cardiac Risk Index (RCRI) criteria supplemented by age, preoperative electrocardiography (EKG) features, and all types of diabetes to the RCRI criteria, predicts long-term (3-15 years) survival after major vascular surgery. The present study aimed to investigate the performance of LTSS in predicting earlier survival (3 months-3 years) as compared with the RCRI.

METHODS

Data from 921 consecutive patients undergoing major vascular surgery (624 patients at Hadassah Medical Center [HMC] and 296 patients in Beth Israel Deaconess Medical Center [BIDMC]) were collected retrospectively. The LTSS was seven points that included the five RCRI factors as well as age >65 years and ST-segment depression on preoperative EKG. Logistic regression and receiver operating characteristic curve (ROC) curve analyses were used to compare the 3 months-3 years mortality between the RCRI and LTSS.

RESULTS

The Beth Israel Deaconess Medical Center patients were sicker than the Hadassah Medical Center patients, with higher RCRI (1.2 ± 1.0 vs. 0.81 ± 0.83, p < 0.001) and LTSS (2.6 ± 1.4 vs. 1.7 ± 1.2, p < 0.001) and higher 3-years mortality (36.3% vs. 20.7%, p = 0.005). The LTSS predicted mortality better than RCRI as measured by the area under the ROC curves at all time points between 6 months (0.66 ± 0.03 vs. 0.57 ± 0.04, p = 0.02) and 3 years (0.70 ± 0.02 vs. 0.61 ± 0.02, p < 0.0001) in both institutions, but not 3-months mortality. The LTSS also provided better discrimination between each adjacent two-risk score than the RCRI.

CONCLUSIONS

Age >65 years, ST-segment depression on preoperative 12-lead EKG, and all types of diabetes added to the RCRI significantly improved the preoperative prediction of mortality after 6 months following major vascular surgery.

A review of the use of common antiplatelet agents in orthopaedic practice

Antiplatelet agents are widely prescribed for the primary and secondary prevention of cardiovascular events. A common clinical problem facing orthopaedic and trauma surgeons is how to manage patients receiving these agents who require surgery, either electively or following trauma. The dilemma is to balance the risk of increased blood loss if the antiplatelet agents are continued peri-operatively against the risk of coronary artery/stent thrombosis and/or other vascular event if the drugs are stopped. The traditional approach of stopping these medications up to two weeks before surgery appears to pose significant danger to patients and may require review. This paper covers the important aspects regarding the two most commonly prescribed antiplatelet agents, aspirin and clopidogrel.

The value of routine preoperative electrocardiography in predicting myocardial infarction after noncardiac surgery

OBJECTIVE

The added value of a preoperative electrocardiogram (ECG) in the prediction of postoperative myocardial infarction (POMI) and death was compared with clinical risk factors identified from the patient's history.

SUMMARY OF BACKGROUND DATA

An ECG is frequently performed before surgery to screen for asymptomatic coronary artery disease. However, the value of ECG abnormalities to predict POMI has been questioned.

METHODS

The study included 2967 noncardiac surgery patients >50 years of age from 2 university hospitals, who were expected to stay in the hospital for >24 hours. All data were obtained from electronic record-keeping systems. Patient history and ECG abnormalities were considered as potential predictors. Multivariate logistic regression analysis was used to obtain the independent predictors of POMI and all-cause in-hospital mortality. The area under the receiver operating characteristic curve (ROC area) was estimated to evaluate the ability of different models to discriminate between patients with and without the outcome.

RESULTS

A preoperative ECG was available in 2422 patients (80%) and 1087 (45%) of the ECGs showed at least one abnormality. The ROC area of the model that included the independent predictors of POMI obtained from patient history, ie, ischemic heart disease and high-risk surgery, was 0.80. ECG abnormalities that were associated with POMI were a right and a left bundle branch block. After adding these abnormalities in the regression model, the ROC area remained 0.80. Similar results were found for all-cause mortality.

CONCLUSIONS

Bundle branch blocks identified on the preoperative ECG were related to POMI and death but did not improve prediction beyond risk factors identified on patient history.

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.

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.

Long-term prognostic value of the preoperative 12-lead electrocardiogram before major noncardiac surgery in coronary artery disease

BACKGROUND

Knowledge of the prognostic information of preoperative 12-lead electrocardiogram (ECG) recordings in patients with coronary artery disease (CAD) undergoing noncardiac surgery is limited.

METHODS

The prognostic information derived from the preoperative ECGs of 172 CAD patients undergoing major noncardiac surgery was analyzed to determine its predictive value for long-term outcome. Primary end point was all-cause mortality; secondary end point was major adverse cardiac events (MACE) at 2 years.

RESULTS

Prevalence of ECG abnormalities was 53% for T-wave alterations; 46% for Q waves; 38% for ST deviations; and, depending on the criterion used, 2% to 19% for left ventricular hypertrophy. During follow-up, 40 (23%) patients died and 31 (18%) had MACE. After adjustment for clinical baseline findings, including current medication with beta-blockers, ST depressions (odds ratio [OR] 4.5, 95% confidence interval [CI] 1.9-10.5) and faster heart rate (HR) (OR 1.6, 95% CI 1.1-2.4, per 10 beats per minute [bpm] increase) were independent predictors of all-cause mortality. Faster HR (OR 1.7, 95% CI 1.1-2.6, per 10-bpm increase) was also an independent predictor of MACE. The predictive value of ECG variables did not change after adjustment for occurence of perioperative ischemia.

CONCLUSION

In CAD patients, the preoperative ECG contains important prognostic information and is predictive of long-term outcome independent of clinical findings and perioperative ischemia.

[Preoperative evaluation and perioperative management of patients with increased cardiovascular risk]

Due to the increasing age in western countries, combined with high rates of major surgical interventions in high-risk patients, perioperative reduction of cardiovascular complications becomes increasingly more important for perioperative physicians. After identifying patients with increased perioperative risk, specific interventions need to be considered to reduce their risk for cardiovascular complications, either by perioperative medical therapy or specific treatment options (e.g. coronary intervention). Several trials have demonstrated an effect of perioperative beta-blocker-therapy in reducing cardiovascular complications among high-risk patients. Additionally, several monitoring techniques are effective in detecting cardiovascular complications. Nevertheless, it remains unclear whether they are associated with a measurable improvement of outcome. Based on the ACC/AHA-guidelines, the present review describes a stepwise approach to surgical patients to identify perioperative risks, based on specific patient related risk factors, the kind of surgery and on the specific setting (emergency versus elective surgery). In addition, strategies to reduce perioperative cardiovascular complications are discussed.

Age associated issues: geriatrics

The effects of aging on the body are numerous, but the most important point with regard to surgery is to differentiate the effects of aging from those of the pathology associated with a disease process that may also be present in the elderly patient. Studies tend to validate the premise that there are no labs mandated solely because of a patient's age. Rather, the physician should analyze the geriatric patient with reference to the nature of the surgery emergent versus elective; the degree of risk for the surgical procedure itself-that is high-risk, intermediate--risk, or low-risk surgery; while bearing in mind the patient's overall physiologic state. In assessing a patient's overall physiologic state an organ systems based approach focusing on the cardiac, respiratory, renal, hepatic, endocrine, nutritional, and neurologic systems may be warranted and beneficial. In the elderly population one of the key predictors of perioperative complications seems to be the geriatric patient's preoperative condition and preoperative level of functioning.

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.

Preoperative electrocardiogram abnormalities do not predict postoperative cardiac complications in geriatric surgical patients

OBJECTIVES

Preoperative electrocardiograms (ECGs) are routinely performed on older patients before surgery. Whether patients with abnormalities on preoperative ECGs have an increased likelihood of developing postoperative cardiac complications is unknown. This study was designed to determine whether abnormalities on preoperative ECGs were predictive of postoperative cardiac complications.

DESIGN

Prospective observational study.

SETTING

One of the teaching hospitals of the University of California, San Francisco, Medical Center.

PARTICIPANTS

Five hundred thirteen patients aged 70 and older undergoing noncardiac surgery.

MEASUREMENTS

Preoperative ECGs were analyzed using the Minnesota Codes. Predefined preoperative risk factors and in-hospital postoperative cardiac complications were measured. The association between ECG abnormalities and postoperative cardiac complications was determined by multivariate logistic regression after controlling for clinical covariates. Odds ratios (ORs) and 95% confidence intervals (CIs) were reported.

RESULTS

Three hundred eighty-six of 513 patients (75.2%) had at least one abnormality on their preoperative ECGs. On multivariate analysis, the predictors of postoperative cardiac complications included American Society of Anesthesiologists physical status classification of 3 or greater (OR = 2.5, 95%CI = 1.28-4.89, P = .007) and a history of congestive heart failure (OR = 2.1, 95% CI = 1.1-5.1, P = .034). The presence of abnormalities on preoperative ECGs was not associated with an increased risk of postoperative cardiac complications (OR = 0.63, 95% CI = 0.28-1.40, P = .26).

CONCLUSION

Abnormalities on preoperative ECGs are common but are of limited value in predicting postoperative cardiac complications in older patients undergoing noncardiac surgery. These results suggest that obtaining preoperative ECGs based on an age cutoff alone may not be indicated, because ECG abnormalities in older people are prevalent but nonspecific and less useful than the presence and severity of comorbidities in predicting postoperative cardiac complications.

Local anesthetic actions on thromboxane-induced platelet aggregation

Some local anesthetics (LA), in concentrations present in blood during IV or epidural infusion, inhibit thrombus formation in the postoperative period. Studies on thromboxane A2 (TXA2) signaling in a recombinant model suggest that interference with TXA2-induced platelet aggregation may explain, in part, the antithrombotic actions of epidural analgesia and IV LA infusion. In this study we investigated the effects of clinically used LAs (lidocaine, ropivacaine, and bupivacaine) on TXA2-induced early platelet aggregation (1-5 s) by using quenched-flow and optical aggregometry. Our findings demonstrate that the LAs tested seem to have only a limited ability to inhibit TXA2-induced platelet aggregation assessed at early times (1-5 s). Therefore, the clinical effects of LAs on thrombi formation are unlikely to be explained by this manner alone. At large LA concentrations, moderate effects were obtained. Prolonged incubation with LA did not significantly increase effectiveness, and the lack of an effect could not be explained by generation of secondary mediators. The results were independent of the anesthetic studied. Local anesthetic effects on TXA2-induced early platelet aggregation (1-5 s) are unlikely to play a major role in the clinically observed antithrombotic effects of local anesthetics.

IMPLICATIONS

Local anesthetic effects on thromboxane A2-induced early platelet aggregation (1-5 s) are unlikely to play a major role in the clinically observed antithrombotic effects of local anesthetics. Thus, other potential targets need to be explored.

Minimizing perioperative adverse events in the elderly

Elderly patients still have the highest postoperative mortality and morbidity rate in the adult surgical population. Preoperative clinical assessment to detect patients at high risk of postoperative events, and specific intraoperative and postoperative anaesthesia management are important to minimize postoperative adverse events in the elderly.

Myocardial infarction after vascular surgery: the role of prolonged stress-induced, ST depression-type ischemia

OBJECTIVES

The goal of this study was to investigate the nature of the association between silent ischemia and postoperative myocardial infarction (PMI).

BACKGROUND

Silent ischemia predicts cardiac morbidity and mortality in both ambulatory and postoperative patients. Whether silent stress-induced ischemia is merely a marker of extensive coronary artery disease or has a closer association with infarction has not been determined.

METHODS

In 185 consecutive patients undergoing vascular surgery, we correlated ischemia duration, as detected on a continuous 12-lead ST-trend monitoring during the period 48 h to 72 h after surgery, with cardiac troponin-I (cTn-I) measured in the first three postoperative days and with postoperative cardiac outcome. Postoperative myocardial infarction was defined as cTn-I >3.1 ng/ml accompanied by either typical symptoms or new ischemic electrocardiogram (ECG) findings.

RESULTS

During 11,132 patient-hours of monitoring, 38 patients (20.5%) had 66 transient ischemic events, all but one denoted by ST-segment depression. Twelve patients (6.5%) sustained PMI; one of those patients died. All infarctions were non-Q-wave and were detected by a rise in cTn-I during or immediately after prolonged, ST depression-type ischemia. The average duration ofischemia in patients with PMI was 226+/-164 min (range: 29 to 625), compared with 38+/-26 min (p = 0.0000) in 26 patients with ischemia but not infarction. Peak cTn-I strongly correlated with the longest, as well as cumulative, ischemia duration (r = 0.83 and r = 0.78, respectively). Ischemic ECG changes were completely reversible in all but one patient who had persistent new T wave inversion. All ischemic events culminating in PMI were preceded by an increase in heart rate (delta heart rate = 32+/-15 beats/min), and most (67%) of them began at the end of surgery and emergence from anesthesia.

CONCLUSIONS

Prolonged, ST depression-type ischemia progresses to MI and is strongly associated with the majority of cardiac complications after vascular surgery.