Critical appraisal of cardiac risk stratification before elective vascular surgery

This study was undertaken to evaluate the efficacy of the cardiac risk stratification protocol proposed by the American College of Cardiology/American Heart Association (ACC/AHA) in predicting cardiac morbidity and mortality associated with elective, major arterial surgery. Cardiac risk stratification using ACC/AHA guidelines was done on 425 consecutive patients before 481 elective cerebrovascular (n = 146), aortic/inflow (n = 166), or infrainguinal (n = 169) procedures at an academic Veterans Affairs Medical Center. Cardiac risk was stratified as low, intermediate, or high based on clinical risk factors, such as, Eagle criteria, history of cardiac intervention, patient functional status, results of noninvasive cardiac stress testing, and coronary angiography with coronary revascularization performed when appropriate. Outcomes (myocardial infarction, unstable angina, congestive heart failure, ventricular arrhythmia, cardiac death, and mortality) within 30 days of surgery were compared between the various risk stratification groups. Univariate and multivariate analyses were used to identify clinically useful prognostic variables from the preoperative cardiac evaluation algorithm. Overall mortality (1.7%), cardiac death (0.4%), and adverse cardiac event (4.8%) rates were low, but cardiac death and morbidity were increased (p < 0.05) in high-risk stratified patients (3.4%, 11.9%) compared to intermediate (0%, 2.8%) and low (0%, 4.0%) cardiac risk groups. The presence of 3-vessel angiographic coronary artery occlusive disease was an independent predictor of cardiac morbidity, while inducible ischemia by cardiac stress imaging was not. Previous coronary revascularization was associated with increased mortality as was the development of a non-cardiac complication. Cardiac risk assessment identified 78 (18%) patients with indications for coronary angiography. Angiographic findings resulted in coronary artery intervention (9-angioplasty; 4-bypass grafting) in 13 (3%) patients who experienced no adverse cardiac events after the planned vascular surgery (15 procedures). Cardiac risk stratification using ACC/AHA guidelines can predict adverse cardiac events associated with elective vascular surgery; however, protocol modification by increased reliance on Eagle criteria and less use of cardiac stress testing can improve identification of the "highest risk" patients who may benefit from prophylactic coronary intervention.     

Guidelines for cardiac management in noncardiac surgery are poorly implemented in clinical practice: results from a peripheral vascular survey in the Netherlands

BACKGROUND: The American College of Cardiology (ACC)/American Heart Association (AHA) guidelines for Perioperative Cardiovascular Evaluation for Noncardiac Surgery recommend an algorithm for a stepwise approach to preoperative cardiac assessment in vascular surgery patients. The authors' main objective was to determine adherence to the ACC/AHA guidelines on perioperative care in daily clinical practice. METHODS: Between May and December 2004, data on 711 consecutive peripheral vascular surgery patients were collected from 11 hospitals in The Netherlands. This survey was conducted within the infrastructure of the Euro Heart Survey Programme. The authors retrospectively applied the ACC/AHA guideline algorithm to each patient in their data set and subsequently compared observed clinical practice data with these recommendations. RESULTS: Although 185 of the total 711 patients (26%) fulfilled the ACC/AHA guideline criteria to recommend preoperative noninvasive cardiac testing, clinicians had performed testing in only 38 of those cases (21%). Conversely, of the 526 patients for whom noninvasive testing was not recommended, guidelines were followed in 467 patients (89%). Overall, patients who had not been tested, irrespective of guideline recommendation, received less cardioprotective medications, whereas patients who underwent noninvasive testing were significantly more often treated with cardiovascular drugs (beta-blockers 43% vs. 77%, statins 52% vs. 83%, platelet inhibitors 80% vs. 85%, respectively; all P < 0.05). Moreover, the authors did not observe significant differences in cardiovascular medical therapy between patients with a normal test result and patients with an abnormal test result. CONCLUSION: This survey showed poor agreement between ACC/AHA guideline recommendations and daily clinical practice. Only one of each five patients underwent noninvasive testing when recommended. Furthermore, patients who had not undergone testing despite recommendations received as little cardiac management as the low-risk population.     

Perioperaive evaluation and management in vascular surgery especially for arteriosclerosis obliterans

Perioperative cardiac event is relatively high in vascular surgery for arteriosclerosis obliterans (ASO), which is a major cause of postoperative death. ACC/AHA guideline and revised cardiac risk index (CRI) were advocated to assess risk factor stratification and to manage risk reduction. ACC/AHA guideline categorized all vascular procedures except carotid endarterectomy as high risk. Because almost all patients with ASO were aged and/or inactive, noninvasive testing was necessary in almost all patients by the stepwise bayesian strategy. Patients with revised CRI less than 1 point dominated about three fourths of all patients, whose prevalence and incidence of ischemic heart disease (IHD) were 2.5% and 1.3%, respectively. It seemed appropriate to apply noninvasive testing only for patients with revised CRI more than 2 points, and high risk indicated coronary angiography. Electrocardigrams obtained at baseline, immediately, and on the first 2 days after surgery appear to be cost-effective to diagnose IHD. Use of cardiac biomarkers was reserved for patients at high risk and those with clinical, or ECG evidence of myocardial infarction (MI). Beta-blockers or alpha-agonists were effective to reduce incidence of perioperative IHD. Although even optimal preoperative assessment and perioperative management, some patients will have perioperative MI.     

Preoperative cardiac evaluation does not improve or predict perioperative or late survival in asymptomatic diabetic patients undergoing elective infrainguinal arterial reconstruction

OBJECTIVE: Patients undergoing infrainguinal arterial reconstruction frequently have increased cardiac risk factors. Diabetic patients are often asymptomatic despite advanced cardiac disease. This study investigates whether preoperative cardiac testing improves the outcome in diabetic patients at risk for cardiac disease. METHODS: We retrospectively reviewed all patients undergoing lower-extremity arterial reconstructions in a 32-month period from July 1999 to February 2002. Of the 433 patients identified undergoing 539 procedures, 295 had diabetes mellitus and considered in this study. The patients were stratified into two groups according to the present American College of Cardiology, American Heart Association (ACC/AHA) algorithm. We identified 140 patients with two or more of ACC (Eagle) criteria who met the inclusion criteria for a preoperative cardiac evaluation. These patients were separated into two groups: those undergoing a cardiac work-up (WU) according to the ACC/AHA algorithm and those not undergoing the recommended work-up (NWU). Outcomes included perioperative mortality, postoperative myocardial infarction, congestive heart failure, arrhythmia, and length of hospitalization. Significance of association was assessed by the Fisher exact test. Length of hospitalization was compared using the Kruskal-Wallis rank sum test. Survival data was analyzed with the Kaplan-Meier method. RESULTS: One hundred forty patients met the criteria for moderate risk. There were 61 patients in the NWU group and 79 in the WU group. Ten patients in the WU group underwent preoperative coronary revascularization (6 had percutaneous transluminal coronary angioplasty, 4 underwent coronary artery bypass grafting). There was no difference between perioperative mortality (WU, 1%; NWU, 2%; P = 1.00) or in postoperative cardiac morbidity, including myocardial infarction, congestive heart failure, and arrhythmia requiring treatment (WU, 5%; NWU, 6%; P = .71). There were no perioperative deaths and one episode of congestive heart failure in the group that had preoperative coronary revascularization. Median length of hospitalization was 10 days in the WU group and 8 days in the NWU group ( P = .11). Patient survival at 12 months for the NWU, WU, and revascularized groups was 85.3%, 78.5%, and 80.0%, respectively; 36-month survival was 73.6%, 62.9%, and 80.0%, respectively. The three survival curves did not differ significantly ( P = .209). CONCLUSIONS: Preoperative cardiac evaluation, as defined by the ACC/AHA algorithm, does not predict or improve postoperative morbidity, mortality, or 36-month survival in asymptomatic, diabetic patients undergoing elective lower-extremity arterial reconstruction. These data do not support the current ACC/AHA recommendations as a standard of care for diabetic patients with an intermediate clinical predictor who undergo peripheral arterial reconstruction, a high-risk surgical procedure.     

Comparison of ejection fraction and Goldman risk factor analysis to dipyridamole-thallium 201 studies in the evaluation of cardiac morbidity after aortic aneurysm surgery

Associated coronary artery disease is the critical factor that influences early and late mortality after abdominal aortic aneurysm surgery. Dipyridamole-thallium 201 scintigraphy, left ventricular ejection fraction, and Goldman risk factor analysis have been suggested as preoperative noninvasive screening methods to detect significant coronary artery disease. In this series of 95 elective abdominal aortic aneurysm repairs dipyridamole-thallium 201 scintigraphy was highly predictive of the absence of perioperative cardiac morbidity (96% specificity, 44/46 normal scans, no cardiac morbidity), whereas ejection fraction (73% specificity, 31/42 normal ejection fraction, no cardiac morbidity) and Goldman risk factor analysis (84% specificity, 44/51 class I, no cardiac morbidity) were less. Furthermore, thallium redistribution on dipyridamole-thallium 201 scintigraphy leading to coronary angiography identified a significant number of patients with occult coronary artery disease who required preoperative coronary revascularization (8%, 8/95) and might have remained undetected on the basis of left ventricular ejection fraction or Goldman risk factor analysis. Finally, fixed thallium deficit, which some investigators have interpreted as a low probability finding for cardiac morbidity, was associated with a higher than expected incidence of cardiac complications. Forty-six percent (7/15) of all postoperative cardiac complications (three myocardial infarctions, three ischemic events, one death) occurred in patients with abdominal aortic aneurysms with fixed deficits. This suggests that patients with fixed deficits on dipyridamole-thallium 201 scintigraphy should be considered for later "delayed" (4 hours) thallium images or coronary angiography or both.     

Limitations in the cardiac risk reduction provided by coronary revascularization prior to elective vascular surgery

OBJECTIVE: The objective of this study was to evaluate the proposed cardiac protective effect of previous coronary revascularization (coronary artery bypass grafting [CABG] or percutaneous transluminal coronary angioplasty [PTCA]) before elective major arterial surgery. METHOD: Preoperative cardiac risk stratification using American College of Cardiology/American Heart Association (ACC/AHA) guidelines was done on 425 consecutive patients undergoing 481 elective major vascular operations at an academic VA Medical Center. The algorithm assumed asymptomatic patients with prior coronary revascularization (CABG, <5 year; PTCA, <2 year) were low cardiac risk. Coronary angiography was done for recurrent symptoms with secondary intervention when appropriate. Outcomes (myocardial infarction, unstable angina, congestive heart failure, ventricular arrhythmia, cardiac death, and mortality) within 30 days of vascular surgery were compared between patients with and without previous CABG or PTCA by contingency table and logistic regression analyses. RESULTS: Coronary revascularization was classified as recent (CABG, <1 year; PTCA, <6 months) in 35 cases (7%), prior (1 year < or = CABG < 5 year, 6 months < or = PTCA < 2 year) in 45 cases (9%), and remote (CABG, > or = 5 year; PTCA, > or = 2 year) in 48 cases (10%). A larger fraction of patients with previous revascularization possessed pathologic cardiac risk variables and were stratified as high-risk preoperatively than their nonrevascularized counterparts. Outcomes in patients with previous PTCA were similar to those after CABG (P =.7). Significant differences in adverse cardiac events (P =.01) and mortality (P =.05) were found between patients with CABG done within 5 years or PTCA within 2 years (6.3%, 1.3%, respectively), individuals with remote revascularization (10.4%, 6.3%), and nonrevascularized patients stratified at high risk (13.3%, 3.3%) or intermediate/low (2.8%, 0.9%) risk. De novo or recurrent 3-vessel coronary disease by angiography, but not the presence or timing of previous revascularization, was an independent predictor of cardiac events after vascular operations, whereas remote revascularization was associated with fatal outcomes by multivariate analysis. CONCLUSIONS: Previous coronary revascularization (CABG, <5 years; PTCA, <2 years) may provide only modest protection against adverse cardiac events and mortality following major arterial reconstruction.     

Guidelines for Cardiac Management in Noncardiac Surgery Are Poorly Implemented in Clinical Practice: Results from a Peripheral Vascular Survey in The Netherlands

Background: The American College of Cardiology (ACC)/American Heart Association (AHA) guidelines for Perioperative Cardiovascular Evaluation for Noncardiac Surgery recommend an algorithm for a stepwise approach to preoperative cardiac assessment in vascular surgery patients. The authors' main objective was to determine adherence to the ACC/AHA guidelines on perioperative care in daily clinical practice.

Methods: Between May and December 2004, data on 711 consecutive peripheral vascular surgery patients were collected from 11 hospitals in The Netherlands. This survey was conducted within the infrastructure of the Euro Heart Survey Programme. The authors retrospectively applied the ACC/AHA guideline algorithm to each patient in their data set and subsequently compared observed clinical practice data with these recommendations.

Results: Although 185 of the total 711 patients (26%) fulfilled the ACC/AHA guideline criteria to recommend preoperative noninvasive cardiac testing, clinicians had performed testing in only 38 of those cases (21%). Conversely, of the 526 patients for whom noninvasive testing was not recommended, guidelines were followed in 467 patients (89%). Overall, patients who had not been tested, irrespective of guideline recommendation, received less cardioprotective medications, whereas patients who underwent noninvasive testing were significantly more often treated with cardiovascular drugs ([beta]-blockers 43% vs. 77%, statins 52% vs. 83%, platelet inhibitors 80% vs. 85%, respectively; all P < 0.05). Moreover, the authors did not observe significant differences in cardiovascular medical therapy between patients with a normal test result and patients with an abnormal test result.     

Audit sur l’évaluation cardiaque préopératoire avant une chirurgie non cardiaque : utilité d’un aide-mémoire pour améliorer l’adhésion des anesthésistes aux recommandations de l’American College of Cardiology/American Heart Association (ACC/AHA)

Introduction

The American College of Cardiology/American Heart Association (ACC/AHA) guidelines stratify perioperative cardiac risk according to clinical markers, functional capacity, and type of surgery. They help determining which patients are candidates for preoperative cardiac testing and optimizing the cost-effectiveness of the evaluation strategy. Auditing our preoperative anaesthetic screening practice revealed an exceedingly high rate of referrals to the cardiologists. A small pocket-size reminder was created in order to improve the adhesion of the anaesthesiologists to the recommendations of the ACC/AHA, and confirm or obviate the need for a formal preoperative specialized cardiology consultation. Another audit was conducted 1 year later in order to evaluate the effectiveness of this reminder.

Methods

The second audit was conducted over a period of 1 month. Recorded data included demographic characteristics, clinical predictors of cardiovascular risk, surgical risk, and the reasons for the cardiac evaluation by a cardiologist (as reported by the senior or junior anaesthesiologist). Results of this second audit were compared to those of the audit conducted a year earlier.

Results

During the first audit, a total of 654 patients were seen in the preoperative unit. Fifty-two patients were referred to a cardiologist during the study period (7.9%). Guidelines for cardiac assessment were respected in 7/52 patients (13.5%). During the second audit, 30 out of 787 patients (3.8%) screened in preoperative anaesthetic consultation unit were referred to the cardiologist. According to the ACC/AHA guidelines, 27/30 patients (90%) objectively needed a cardiology consultation due to the existence of a known previous heart disease.

Discussion

The use of the pocket reminder concerning the ACC/AHA recommendations significantly reduced both the total number of cardiology referrals, and the number of unjustified referrals. The use of a pocket guide may help in reducing both the cost and the postponement of scheduled surgery.     

Preoperative cardiac evaluation of the vascular surgery patient--an anesthesia perspective

The morbidity and mortality associated with vascular surgery procedures are largely the results of cardiac events. National guidelines have been regularly proposed and updated by the American College of Cardiology (ACC)/American Heart Association (AHA) to ensure optimal perioperative management and risk stratification. Controversy remains between experts and other cardiology societies regarding several patient care issues including revascularization before surgery, timing of β-blocker therapy, and the administration of antiplatelet therapy. Several landmark articles recently published have helped to modify the guidelines in the hope of improving vascular patient outcomes. In this review, we searched all recent available literature pertaining to perioperative cardiac evaluation before major vascular surgery. We propose an algorithm for preoperative cardiac evaluation, which is a modification to the AHA recommendations. Incorporated in this algorithm are recent published pivotal articles that can help in guiding physicians caring for the vascular patient requiring major operative or endovascular interventions.     

Evaluation,severity and prognostic significance of silent myocardial ischaemia in vascular patients

This paper intends to make an update of recent publications and guidelines for evaluation in coronary symptom-free patients undergoing vascular surgery. It emphasizes the role of preoperative clinical evaluation that should identify the most appropriate testing, and treatment strategies to optimize care of the patient and avoid unnecessary testing in this era of cost containment. Selective preoperative coronary artery disease screening and revascularization achieve excellent perioperative and late results after high-risk vascular surgery. Supplemental preoperative evaluation is discussed (exercise ECG, stress echocardiography and stress tomoscintigraphy). Asymptomatic patients with good functional capacity can undergo intermediate-risk surgery without further non-invasive testing. Conversely, further noninvasive testing is often considered for patients with poor functional capacity or moderate functional capacity but higher-risk surgery especially for patients with 2 or more intermediate risk predictors. Additional testing may be considered on an individual basis for patients without clinical markers but with poor functional capacity prior to vascular surgery, particularly those with several minor clinical risk predictors. Because of a higher prevalence of silent myocardial ischaemia in diabetes mellitus, these patients require specific care. Until further data are available, indications for myocardial revascularization in the perioperative setting are similar to those in the ACC/AHA guidelines for use of myocardial revascularization in general. General practitioners, cardiologists, angiologists, vascular surgeons and anaesthesiologists should collaborate and aim to slow down the progression of atherosclerosis by giving their patients an optimum secondary cardiovascular prevention.     

Evaluation,Severity and Prognostic Significance of Silent Myocardial Ischaemia in Vascular Patients

This paper intends to make an update of recent publications and guidelines for evaluation in coronary symptom-free patients undergoing vascular surgery. It emphasizes the role of preoperative clinical evaluation that should identify the most appropriate testing, and treatment strategies to optimize care of the patient and avoid unnecessary testing in this era of cost containment. Selective preoperative coronary artery disease screening and revascularization achieve excellent perioperative and late results after high-risk vascular surgery. Supplemental preoperative evaluation is discussed (exercise ECG, stress echocardiography and stress tomoscintigraphy). Asymptomatic patients with good functional capacity can undergo intermediate-risk surgery without further non-invasive testing. Conversely, further noninvasive testing is often considered for patients with poor functional capacity or moderate functional capacity but higher-risk surgery especially for patients with 2 or more intermediate risk predictors. Additional testing may be considered on an individual basis for patients without clinical markers but with poor functional capacity prior to vascular surgery, particularly those with several minor clinical risk predictors. Because of a higher prevalence of silent myocardial ischaemia in diabetes mellitus, these patients require specific care. Until further data are available, indications for myocardial revascularization in the perioperative setting are similar to those in the ACC/AHA guidelines for use of myocardial revascularization in general. General practioners, cardiologists, angiologists, vascular surgeons and anaes-thesiologists should collaborate and aim to slow down the progression of atherosclerosis by giving their patients an optimum secondary cardiovascular prevention.     

Low negative predictive value of dobutamine stress echocardiography before abdominal aortic surgery

Background. According to previous studies, a negative dobutaminestress echocardiography (DSE) test before major vascular surgeryindicates that postoperative myocardial necrosis is very unlikely.We believe that the use of new cardiac troponin assays whichcan detect small amounts of myocardial necrosis results in alower DSE negative predictive value for myocardial necrosis. Methods. A total of 418 consecutive patients were screened usingthe ACC/AHA Guideline for Perioperative Cardiovascular Evaluationfor Noncardiac Surgery before scheduled abdominal aortic surgery.Of these 143 met ACC/AHA criteria for non-invasive testing andunderwent DSE. Patients with a negative DSE were deemed to befit for surgery. A positive DSE led to a coronary angiogram.DSE was negative in 110 (77%) and positive in 33 (23%) patients.Myocardial necrosis was monitored up to the third postoperativeday by daily cardiac troponin I (cTnI) measurement and a daily12-lead ECG. Results. Coronary angiography showed artery stenosis in 27 (84%)of 32 patients with a positive DSE. The negative predictivevalue of DSE for cTnI elevation was 92.7% (95% CI 86.2–96.8%).This was significantly lower than the lowest value of negativepredictive value for myocardial necrosis assessed in previousstudies. Conclusion. A negative DSE prescribed before scheduled aorticsurgery according to ACC/AHA guidelines does not rule out postoperativemyocardial necrosis.     

Lowering cardiac risk by preoperative interventions

Postoperative myocardial infarction still represents a serious complication in patients with coronary artery disease, after the first 48 hours following non cardiac surgery (NCS). To reduce the incidence, patient's status should be optimised, including CABG, PTCA and stenting, before the NCS. Indications for CABG, PTCA and stenting suggested by ACC/AHA are in general applicable also for NCS. Patients undergoing low and intermediate risk procedures would not benefit from extensive testing and CABG, while a potential benefit exists for high risk surgery in severe CAD patients. Revascularisation by means of PTCA seems to decrease the risk only if it is performed more than 90 days before the NCS. By the contrary, the combination of PTCA and stenting reduces incidence of coronary re-stenosis, but it increases bleeding, thrombosis and distal embolisation, especially if not supported by an anti-platelet or combined pharmacological schedule; therefore, perioperative stenting is not recommended to increase safety. Moreover, if NCS is urgent, despite a recent stenting, the patient should be included in a high risk group.     

Surgery for esophageal cancer complicate with cardiovascular disease

A risk of cardiac complications is one of the most significant risks to patient undergoing major surgery. Especially, for the patients with cancer, the preoperative management can be complex. The direct effect of cancer and side effect of prior chemotherapy or radiation therapy should be considered. The 2007 American College of Cardiology/American Heart Association( ACC/AHA) guidelines on perioperative cardiovascular evaluation for noncardiac surgery concluded that 3 elements must be assessed to determine the risk of cardiac event. The preoperative risk in a patient is initially assessed by the presence or absence of clinical predictors of increased perioperative cardiovascular risk, the patient's level of cardiac function, and the underlying risk of the surgical procedure. Here we will provide an overview of issue that are relevant to patients with esophageal cancer.     

Algorithm of cardiac risk assessment before vascular surgery

THE OBJECT: to detect the informative value of algorithm of cardiac risk assessment recommended by American Heart Association compared with original standard enlarged protocol. Overall 456 patients underwent vascular operations. First group consisted of 198 patients who were examined according original enlarged protocol; other 258 patients (2nd group) were examined with AHA protocol. At 1st group 41% patients didn't need myocardial revascularization (according coronarography results), preventive coronary bypass surgery was performed at 32% patients. At 2nd group coronarography was performed at 133 (51%) patients according risk factors stratification and stress-examination results. Preventive coronary bypass surgery was performed at 97 patients; 27 patients refused this recommendation. Enlarged protocol increases in 2.6 times the odds of unnecessary invasive procedure. It is concluded that AHA algorithm permits to reduce in 2 times and more the number of invasive diagnostic procedures compared with standard enlarged protocol; AHA algorithm increases the clinical and economic effectiveness.     

围腹部手术期患者伴有心脏支架的处理策略

美国心脏病学会联合美国心脏协会(ACC/AHA)和欧洲的心脏协会(ESC)相继发布了非心脏手术围手术期心血管评估与治疗指南推荐,对心脏支架患者非心脏手术围手术期的治疗提出指导意见,但是对非心脏手术的时机选择、围手术期抗凝治疗等问题仍有争议。掌握心脏支架患者腹部围手术期的处理相关策略,对减少围手术期心脏相关并发症至关重要。     

Simultaneous cardiac operations with pulmonary resection for lung carcinoma

OBJECTIVES: A procedure remains to be established for managing patients with both cardiac and pulmonary diseases requiring surgical interventions. We review our experience with 6 patients having cardiac disease and lung cancer surgically treated simultaneously to determine whether simultaneous surgery is safe and effective. METHODS: Subjects were 6 men with a mean age of 64 +/- 10 years undergoing cardiac surgery combined with pulmonary lobectomy from January 1986 through June 2000. Cardiac procedures consisted of coronary artery bypass in 3, coronary artery bypass plus left ventricular aneurysm repair, aortic valve replacement, and minimally invasive direct coronary artery bypass surgery in 1 patient each. All underwent lobectomy. RESULTS: No early deaths occurred. Bleeding complications occurred in 2 patients and lymph node dissection was incomplete in 3. Two died of carcinoma-related events, 1 at 28 and the other at 84 months after surgery. One died suddenly from a cardiac-related event 42 months after surgery. Only 1 patient is currently alive and disease-free at 104 months after surgery. CONCLUSION: Simultaneous surgery can be conducted with acceptable mortality. The occurrence of bleeding complications and incomplete lymph node dissection, however, indicates combined procedures only in patients requiring simultaneous surgery due to their disease or unable to tolerate a second operation.     

Low utility of dobutamine stress echocardiograms in the preoperative evaluation of patients scheduled for noncardiac surgery

In this study, we examined the utility of preoperative dobutamine stress echocardiograms (DSE) obtained for 85 patients in accordance with guidelines published by the American College of Cardiology (ACC) and the American Heart Association (AHA). The medical record of each patient was reviewed to identify the clinical criteria that indicated the need for a DSE, the DSE results, therapeutic interventions rendered as a result of the DSE, and any perioperative cardiac morbidity. The DSE was positive for inducible ischemia in 4 patients (4.7%), negative in 74 (87.1%), and nondiagnostic in 7 (8.2%). DSEs that were obtained for 48 patients because of a history of diabetes mellitus, mild angina, or "minor clinical predictors" produced only negative results. Of the four patients with positive DSE results, three underwent coronary angiography, and one of those three underwent bypass grafting before surgery. An additional 29 patients received a preoperative DSE but were excluded from the study because the criteria for ordering the DSE did not meet the ACC/AHA guidelines. No patient had any perioperative morbidity related to myocardial ischemia. The total patient charge for the 85 DSEs obtained at our institution was US$104,635. Use of the ACC/AHA guidelines for preoperative DSEs does not appear to be cost-effective. However, the current algorithm could be significantly improved by altering the criteria for obtaining preoperative DSEs. IMPLICATIONS: This study was a retrospective review of 85 patient charts that found a low cost-effectiveness of using American College of Cardiology/American Heart Association guidelines for obtaining preoperative dobutamine stress echocardiograms. Suggested modifications of these guidelines should improve their specificity with no loss in sensitivity.     

Anaesthesia for abdominal aortic surgery — a review (Part II)

Patients presenting for abdominal aortic surgery have a high incidence of vascular disease elsewhere, manifested primarily by hypertension, coronary and cerebrovascular disease, as well as co-existing respiratory, renal and metabolic disorders. Routine clinical assessment, electrocardiogram, chest roentgenograms, resting and exercise radionuclide ventriculography and echocardiography, dipyrdiamole-thallium scanning are all designed to assess the functional status of the myocardium and to detect the presence of significant coronary artery disease. Patients with no abnormalities on physical examination, routine evaluation and no redistribution on dipyridamole-thallium scanning should proceed to surgery with the expectation of very low perioperative cardiac risk. Patients with evidence of coronary artery disease and significant redistribution on dipyridamole-thallium scan should undergo coronary angiography and possible myocardial revascularization before definitive aortic vascular surgery. For high cardiac risk patients with no bypassable lesions presenting for abdominal aortic aneurysm resection a conservative policy of serial three monthly ultrasound or CT assessment may be adopted, with selective resection for rapid aneurysm expansion or symptom development. A variety of extra-anatomical and angioplastic techniques is available for similar high cardiac risk patients with aortoiliac occlusive disease. The haemodynamic consequences of aortic cross-clamping, especially in aneurysm patients, include a significant reduction in stroke volume, cardiac index, and myocardial oxygen consumption with an increased systemic vascular resistance. Patients with coronary artery disease may respond to aortic cross-clamping by increasing pulmonary capillary wedge pressure and by demonstrating ECG evidence of myocardial ischaemia. Pulmonary artery catheterization is especially indicated in patients with a history of previous myocardial infarction, angina or signs of cardiac failure and in patients with evidence of diminished ejection fraction, abnormal ventricular wall motion or myocardial redistribution on preoperative scanning. The more widespread application of intraoperative transoesophageal two-dimensional echocardiography and radionuclide cardiography monitoring techniques into anaesthetic practice will enable measurement of left ventricular dimensions, myocardial performance and wall motion. Suggested guidelines for anaesthetic management are presented in Table VI. A combined opiate-oxygen-volatile anaesthetic agent technique will best ensure a hypodynamic circulation with preservation of myocardial oxygenation.(ABSTRACT TRUNCATED AT 400 WORDS)     

非心脏手术围术期心脏事件危险评估与保护性干预

围术期心脏事件是非心脏手术围手术期严重并发症和死亡的重要原因。在临床广泛应用的修订心脏风险指数及ACC／AHA制定的非心脏手术围术期评估指南．可协助临床医生评价非心脏手术心脏风险并做出围术期诊治决策。β受体阻滞剂和他汀类药物可减少高危患者非心脏手术围术期心脏事件及死亡的发生,术前血管重建治疗对于严重冠心病患者是必要和有益的。