Preoperative management of the patient with coronary artery disease before abdominal aortic surgery

Coronary artery disease accounts for more than half of the morbidity and mortality associated with abdominal aortic surgery. To improve the results of vascular surgery, the risk of perioperative cardiac ischemia should be evaluated in each patient. Routine coronary angiography demonstrated severe correctable coronary artery disease in 14% of patients who had no history or electrocardiographic evidence of coronary artery disease. Exercise testing before abdominal aortic aneurysm repair will identify patients at high risk of cardiac ischemia. Dipyridamole-thallium imaging will identify high-risk patients before surgery for aortoiliac occlusive disease. Some patients with symptomatic coronary disease who are at extremely high risk should undergo preoperative coronary revascularization. Others should have their vascular surgery deferred, because their cardiac risk may exceed the anticipated benefit of the vascular surgery. Patients at moderate risk may need more intensive intraoperative monitoring. Patients without evidence of cardiac ischemia with stress may undergo vascular surgery with a low risk of perioperative cardiac ischemia. Finally, patients who have evidence of ischemic heart disease should be considered for coronary revascularization following successful vascular repair in order to prolong their survival.     

An Appraisal of Different Cardiac Risk Reduction Strategies in Vascular Surgery Patients

OBJECTIVES: to summarize existing evidence regarding the benefits and the risks of all available interventional and medical means aimed at cardiac risk reduction in patients undergoing vascular surgery. DESIGN: review of the literature. MATERIALS AND METHODS: a critical review of all studies examining the impact of various prophylactic cardiac maneuvers on perioperative outcome following vascular surgery was performed. Overall mortality, cardiac mortality and myocardial infarction rate were used as the outcome measures. RESULTS: coronary artery bypass grafting is associated with a 60% decrease in perioperative mortality in patients undergoing vascular surgery, but in most of the cases this decrease does not outweigh the combined risk of the cardiac and the subsequent noncardiac vascular procedure. Data supporting the cardioprotective effect of percutaneous transluminal angioplasty in the perioperative setting are insufficient. beta-blockade has been shown to decrease perioperative mortality and cardiac morbidity in both high-risk (strong evidence) and low-risk (weak evidence) patients. CONCLUSIONS: coronary revascularization is rarely indicated to simply get the patient through vascular surgery and should be reserved for patients who would need it irrespective of the scheduled vascular procedure. Among all available pharmacological agents, including beta-blockers, alpha-agonists, calcium channel blockers and nitrates, only beta-blockers have been proven to reduce the cardiac risk of vascular surgery.     

Preoperative coronary revascularization in high-risk patients undergoing vascular surgery: a core review

Patients undergoing vascular surgery are at increased risk for cardiac complications related to the presence of underlying coronary artery disease. Preoperative cardiac evaluation may help to identify high-risk patients in whom coronary angiography may be planned with subsequent coronary revascularization for the purpose of improving perioperative and long-term cardiac outcomes. However, the indications and efficacy for type of revascularization for the reduction of cardiac complications compared to medical therapy has been controversial. My aim in this review is to summarize the role of preoperative revascularization compared to conservative medical therapy before elective vascular surgery using current evidence from published studies.     

Perioperative mangement of surgery for abdominal aortic aneurysm associated with coronary artery disease

BACKGROUND: Patients undergoing abdominal aortic aneurysm (AAA) surgery are at increased risk of perioperative cardiovascular complications due to underlying coronary artery disease (CAD). We determined retrospectively the incidence of CAD and the influence of coronary revascularization and perioperative cardiovascular complications in patients for AAA surgery. METHODS: Routine coronary angiography (CAG) was performed in 159 patients prior to elective AAA surgery to estimate the presence of CAD. To compare risk factors and perioperative cardiovascular complications the patients were divided at the time of CAG into three groups: previously diagnosed CAD, newly diagnosed CAD and non-CAD. RESULTS: Preoperative CAG found 129 patients (81%) with CAD. Among newly diagnosed patients 82% were asymptomatic of CAD. Forty-four patients (28%) underwent coronary revascularization (17 percutaneous coronary intervention, 3 preoperative coronary artery bypass grafting, and 24 combined coronary artery bypass grafting). Perioperative cardiac complications occurred in 35 patients (22%). No significant difference was found among the three groups in the incidence of perioperative cardiovascular complications. Two patients with severe CAD not treated with coronary revascularization died of cardiac events. CONCLUSIONS: Perioperative management and coronary revascularization should be carried out with more cautions in AAA patients to reduce the incidence of cardiovascular complications after AAA surgery.     

高危患者在血管外科手术前行冠状动脉重建术之利弊综述

血管外科手术患者如合并有冠状动脉疾病,发生心血管并发症的风险将增加。手术前心血管功能评估有助于发现需要进行冠状动脉造影的高危患者,并随后进行冠状动脉重建术,以达到改善围手术期甚至长期心血管转归的目的。但与药物治疗相比,冠状动脉重建手术的适应证和减少心血管并发症的有效性仍存在争议。本文通过分析已发表的文献,探讨与保守的药物治疗相比,手术前行血管重建术在择期血管手术中的作用。     

Preoperative cardiac risk assessment: an updated approach.

HYPOTHESIS: We provide an updated algorithm for approaching preoperative cardiac risk assessment in patients undergoing noncardiac surgery. DESIGN: A National Library of Medicine PubMed literature search was performed dating back to 1985 using the keywords "preoperative cardiac risk for noncardiac surgery." This search was restricted to English language articles involving human subjects. RESULTS: Patient-specific and operation-specific cardiac risk can be determined clinically. Patients with major cardiac risk factors have a high incidence of perioperative cardiac complications, whereas the risk is less than 3% for low-risk patients. For intermediate-risk patients, no prospective randomized studies demonstrate the efficacy of noninvasive stress testing (dipyridamole thallium or dobutamine echocardiography) or of subsequent coronary revascularization for preventing perioperative cardiac complications. Recent studies demonstrate that perioperative beta-blockade significantly reduces the adverse cardiac event rate in intermediate-risk patients. CONCLUSIONS: Most patients with high cardiac risk should proceed with coronary angiography. Patients with low cardiac risk can proceed to surgery without noninvasive testing. For intermediate-risk patients, consideration may be given to further stress testing prior to surgery; however, in most patients, proceeding to surgery with perioperative beta-blockade is an acceptable alternative.     

Risk stratification

Perioperative cardiac complications pose the greatest risk to the estimated 100 million people undergoing non-cardiac surgery each year. Most of these complications are related to underlying pre-existing coronary artery disease (CAD). For over 40 years researchers have been studying perioperative cardiac risk and how best to estimate it. The goal of improved risk stratification is important for allowing accurate informed decision-making, both by the patient and their physicians. Risk stratification has taken on an important role in clinical decision-making, helping physicians decide in which patients additional medical therapies, such as coronary revascularization or perioperative beta-blockers, are necessary. Meta-analysis has found a significant improvement in the positive predictive value (PPV) for perioperative cardiac outcome with stress testing over that with clinical risk score alone. However, evidence is mounting that with the use of perioperative beta-blockers, the majority of intermediate and high-risk patients can safely undergo even major vascular surgery without further cardiac testing.     

Correlation between prior coronary revascularization and perioperative cardiac events in patients for noncardiac surgery

We evaluated the influence of interval between prior coronary revascularization and subsequent noncardiac surgery on perioperative cardiac events. We retrospectively identified 162 consecutive patients with previous revascularization procedures who had undergone noncardiac surgery. Postoperative cardiac complications occurred in 10 (6.2%) patients, cardiac death in 1 patient, and significant arrhythmia in 3 patients. These patients had higher rates of unstable angina, myocardial infarction within 3 months, cerebrovascular disease, peripheral vascular disease, renal dysfunction (Cr > or = 1.9 mg.dl-1) and higher preoperative risk scores as described by the Cleveland Clinic (P < 0.05). Also, the incidence of cardiac complications increased when noncardiac surgery was performed within 1 week of previous percutaneous transluminal coronary angioplasty (PTCA) and in more than 5 years after coronary artery bypass grafting or PTCA (P < 0.05). Although PTCA is widely accepted, especially in Japan, early lesion progression was observed during the first several days and atherosclerotic progression was apparent in more than 5 years after the procedure. Therefore, the time between coronary revascularization and noncardiac surgery, as well as atherosclerotic risk factors, is important in evaluating patients with history of previous revascularization procedures.     

Cardiac risk reduction in non-cardiac surgery: the role of anaesthesia and monitoring techniques

Cardiac complications are the major cause of perioperative morbidity and mortality of patients undergoing non-cardiac surgery. This is related to the frequent presence of underlying coronary artery disease. In the last few decades, attention has focused on preoperative cardiac risk assessment that may help to identify patients at increased cardiac risk for whom cardioprotective medication and, when indicated, coronary revascularization may improve perioperative outcome. On the other hand, less attention was given to the role of anaesthesia and monitoring techniques in the cardiac risk management of high-risk patients undergoing non-cardiac surgery. The aim of this review was to summarize the current evidence from published studies on the effect of the type of anaesthesia and monitoring techniques on perioperative cardiac outcome in non-cardiac surgery.     

Long-term survival after vascular surgery: specific influence of cardiac factors and implications for preoperative evaluation

OBJECTIVE: We sought to identify specific determinants of long-term cardiac events and survival in patients undergoing major arterial operations after preoperative cardiac risk stratification by American College of Cardiology/American Heart Association guidelines. A secondary goal was to define the potential long-term protective effect of previous coronary revascularization (coronary artery bypass grafting [CABG] or percutaneous coronary intervention [PCI]) in patients with vascular disease. METHODS: Four hundred fifty-nine patients underwent risk stratification (high, intermediate, low) before 534 consecutive elective or urgent (<24 hours after presentation) open cerebrovascular, aortic, or lower limb reconstruction procedures between August 1996 and January 2000. Long-term follow-up (mean, 56 +/- 14 months) was possible in 97% of patients. The Kaplan-Meier method was used for survival data. Long-term prognostic variables were identified with the multivariate Cox proportional hazards model and contingency table analysis censoring early (<30 days) perioperative deaths. RESULTS: While 5-year survival was 72% for the overall cohort, cardiac causes accounted for only 24% of all deaths, and new cardiac events (myocardial infarction, congestive heart failure, arrhythmia, unstable angina, new coronary angiography, new CABG or PCI, cardiac death) affected only 4.6% of patients per year during follow-up. High cardiac risk stratification level (hazards ratio [HR], 2.2, 95% confidence interval [CI], 1.4-3.4), adverse perioperative cardiac events (myocardial infarction, congestive heart failure, ventricular arrhythmia; HR, 2.2; 95% CI, 1.2-4.1), and age (HR, 0.33; 95% CI, 0.2-0.6) were independently prognostic for latemortality. Preoperative cardiac risk levels also correlated with new cardiac event rates ( P < .01) and late cardiac mortality ( P = .02). Modestly improved survival in patients who had undergone CABG or PCI less than 5 years before vascular operations compared with those who had undergone revascularization 5 or more years previously and those at high risk without previous coronary intervention (73% vs 58% vs 62% 5-year survival; P = .02) could be demonstrated with univariate testing, but not with multivariate analysis. Type of operation, urgency, noncardiac complications, and presence of diabetes did not affect long-term survival. CONCLUSION: Despite cardiac events being a less common cause of late mortality after vascular surgery, perioperative cardiac factors (age, preoperative risk level, early cardiac complications) are the primary determinants of patient longevity. Patients undergoing more recent (<5 years) CABG or PCI before vascular surgery do not have an obvious survival advantage compared with patients at high cardiac risk without previous coronary interventions.     

Perioperative Cardiac Risk Stratification and Modification in Abdominal Aortic Aneurysm Repair

Cardiovascular complications are important causes of morbidity and mortality following vascular surgery. Adequate preoperative risk assessment and perioperative management may modify postoperative mortality and morbidity and improve long-term prognosis. The objective of this review is to examine the present day knowledge regarding the preoperative evaluation and perioperative management of patients undergoing noncardiac surgery, focusing specifically on abdominal aortic aneurysm (AAA) repair.

Clinical markers combined with ECG and surgical risk assessment can effectively divide patients in a truly low-risk, intermediate and high-risk population. Low-risk patients can probably be operated on without additional cardiac testing. Notably, due to the surgical risk, AAA patients are never low-risk patients. Intermediate-risk and high-risk patients are referred for cardiac testing to exclude extensive stress induced myocardial ischemia, as beta-blockers provide insufficient myocardial protection in this case and preoperative coronary revascularization might be considered. Whether patients at intermediate risk without ischemic heart disease should be treated with statins and/or beta-blockers is still controversial. In high-risk patients, it is strongly advised to administer beta-blockers with heart rate determined dose adjustment, while the effects of preoperative revascularization remain subject to debate.     

Die Bedeutung der perioperativen medikamentösen Therapie für das Ergebnis gefäßchirurgischer Operationen

Cardiac complications after vascular surgery are specific to the patient, the surgery itself, and the circumstances under which surgery was performed. Myocardial infarction and congestive heart failure are the major causes of perioperative morbidity and mortality in patients with cardiac comorbidities undergoing major vascular surgery. The perioperative medical treatment of patients presenting with cardiovascular risk factors is aimed at reducing the incidence of postoperative complications—in an increasing number of patients, due to increasing life expectancy. This paper discusses the impact of beta blockers, statins, and other medical therapy on the prevention of perioperative morbidity. Although it is generally accepted that preoperative treatment with beta blockers constitutes effective prevention of postoperative cardiac complications in high-risk patients, data are needed in order to derive guiding principles addressing the type and duration of beta blocker therapy. Statins are another group of cardioprotective medications that offer, besides lipid-lowering effects, stabilization of atherosclerotic plaque. The effects of alpha-2 agonists and antiplatelet therapy are also discussed.     

Perioperative cardiac risk stratification and modification in abdominal aortic aneurysm repair

Cardiovascular complications are important causes of morbidity and mortality following vascular surgery. Adequate preoperative risk assessment and perioperative management may modify postoperative mortality and morbidity and improve long-term prognosis. The objective of this review is to examine the present day knowledge regarding the preoperative evaluation and perioperative management of patients undergoing noncardiac surgery, focusing specifically on abdominal aortic aneurysm (AAA) repair. Clinical markers combined with ECG and surgical risk assessment can effectively divide patients in a truly low-risk, intermediate and high-risk population. Low-risk patients can probably be operated on without additional cardiac testing. Notably, due to the surgical risk, AAA patients are never low-risk patients. Intermediate-risk and high-risk patients are referred for cardiac testing to exclude extensive stress induced myocardial ischemia, as beta-blockers provide insufficient myocardial protection in this case and preoperative coronary revascularization might be considered. Whether patients at intermediate risk without ischemic heart disease should be treated with statins and/or beta-blockers is still controversial. In high-risk patients, it is strongly advised to administer beta-blockers with heart rate determined dose adjustment, while the effects of preoperative revascularization remain subject to debate.     

Perioperative- and long-term mortality rates after major vascular surgery: the relationship to preoperative testing in the medicare population.

Debate continues regarding the value of cardiovascular testing and coronary revascularization before major vascular surgery. Whereas recent guidelines have advocated selective preoperative testing, several authors have suggested that it is no longer necessary in an era of low perioperative cardiac morbidity and mortality. We used data from a random sample of Medicare beneficiaries to determine the mortality rate after vascular surgery, based on the use of preoperative cardiac testing. A 5% nationally random sample of the aged Medicare population for the final 6 mo of 1991 and first 11 mo of 1992 was used to identify a cohort of patients who underwent elective infrainguinal or abdominal aortic reconstructive surgery. Use within the first 6 mo of 1991 was reviewed to determine if preoperative noninvasive cardiovascular imaging or coronary revascularization was performed. Thirty-day (perioperative) and 1-yr mortalities were assessed. Perioperative mortality was significantly increased for aortic surgery (209 of 2865 or 7.3%), compared with infrainguinal surgery (232 of 4030 or 5.8%); however, 1-yr mortality was significantly increased for infrainguinal surgery (16.3% vs 11.3%, P < 0.05). Stress testing, with or without coronary revascularization, was associated with improved short-and long-term survival in aortic surgery. The use of stress testing with coronary revascularization was not associated with reduced perioperative mortality after infrainguinal surgery. Stress testing alone was associated with reduced long-term mortality in patients undergoing infrainguinal revascularization. IMPLICATIONS: Analysis of the Medicare Claims database suggests that vascular surgery is associated with substantial perioperative and long-term mortality. The reduced long-term mortality in patients who had previously undergone preoperative testing and coronary revascularization reinforces the need for a prospective evaluation of these practices.     

Preoperative cardiac risk management

Approximately 100 million people undergo noncardiac surgery annually worldwide. It is estimated that around 3% of patients undergoing noncardiac surgery experience a major adverse cardiac event. Although cardiac events, like myocardial infarction, are major cause of perioperative morbidity or mortality, its true incidence is difficult to assess. The risk of perioperative cardiac complications depends mainly on two conditions: (1) identified risk factors, and (2) the type of the surgical procedure. On that basis, different scoring systems have been developed in order to accurately assess the perioperative cardiac risk and to improve the patient management. Importantly, patients with estimated high risk should be tested preoperatively by non-invasive cardiac imaging modalities. According to test results, they can proceed directly to planed surgery with the use of cardioprotective drugs (beta-blockers, statins, aspirin), or to myocardial revascularization prior to non-cardiac surgery. In this review, we discuss the role of clinical cardiac risk factors, laboratory measurements, additional non-invasive cardiac testing, and consequent strategies in perioperative management of patients undergoing noncardiac surgery.     

Preoperative risk assessment in vascular surgery patients

The patient scheduled for peripheral vascular surgery is an increased anaesthetic challenge, mainly because of coexisting generalized cardiovascular atherosclerotic involvement leading to a high risk of perioperative cardiac complications. In clinical practice it is of importance preoperatively to predict, as accurately as possible, the potential risk of complications so that proper risk-reducing measures can be taken. Relevant clinical data, which have been included by Goldman and Detsky in multifactorial cardiac risk indices, are of potential value for differentiating between patients at low, intermediate, or high risk of perioperative cardiac morbidity and mortality. Patients with low risk scores can be accepted for surgery without further testing, thereby allowing more extensive cardiac testing, such as ambulatory ECG monitoring, exercise stress testing, echocardiography, dipyridamole thallium imaging, or coronary angiography, to be reserved for patients with higher risk scores or overt cardiac problems. The risk stratification is of importance not only for decisions on preoperative prophylactic therapeutic measures (e.g. optimization of medical therapies, coronary artery revascularization), but also for decisions on intraoperative anaesthetic management and postoperative care.     

Vascular complications of intra-aortic balloon insertion in patients undergoing coronary reavscularization: analysis of 911 cases.

OBJECTIVE: Intra-aortic balloon pump (IABP) is a well-accepted and widely used mechanical circulatory support in cardiac surgical practice. We evaluated the vascular complications of IABP and risk factors associated with the development of these complications in patients undergoing myocardial revascularization. METHODS: Between January 1994 and December 2000, a total of 911 patients undergoing coronary artery bypass grafting received IABP. The preoperative risk factors, balloon-related variables and vascular complications were studied and analyzed. Univariate and multivariate analyses were performed to identify risk factors for the development of vascular complications. RESULTS: Mean age of the patients was 59.2+/-9.1 years and 10.5% of the patients were female. The incidence of diabetes and peripheral vascular disease was 41.1 and 8.5%, respectively. The mean Parsonnet score was 11.8+/-4.6. IABP was inserted by percutaneous technique in 96.8% of patients. The duration of IABP therapy ranged from 20 h to 21 days (mean 3.8 days). Fifty-four (5.9%) patients developed major and 53 (5.8%) patients developed minor vascular complications. Ischaemia of the limb, requiring thromboembolectomy, developed in 25 (2.7%) patients. Patients who received IABP preoperatively had higher incidence of major vascular complications as compared to patients who received IABP in operating room before induction of anaesthesia. Multiple logistic regression analysis revealed age, triple vessel disease, indications of IABP therapy (unstable angina, cardiac arrhythmia and haemodynamic instability), left ventricular aneurysm surgery and use of balloon with sheath as independent risk factors for the development of vascular complications. CONCLUSIONS: IABP therapy is associated with certain vascular complications, which should always be kept in mind before insertion of a balloon. The use of a balloon without sheath and proper evaluation of peripheral circulation can help to minimize the development of vascular complications.     

The impact of a cardioprotective protocol on the incidence of cardiac complications after aortic abdominal surgery

We analyzed a local database including 468 consecutive patients who underwent elective aortic abdominal surgery over an 8-yr period in a single institution. A new cardioprotective perioperative protocol was introduced in January 1997, and we questioned whether perioperative cardiac outcome could be favorably influenced by the application of a stepwise cardiovascular evaluation based on the American College of Cardiology/American Heart Association guidelines and by the use of antiadrenergic drugs. Clonidine was administered during surgery, and beta-blockers were titrated after surgery to achieve heart rates less than 80 bpm. We compared data of two consecutive 4-yr periods (1993-1996 [control period] versus 1997-2000 [intervention period]). Implementation of American College of Cardiology/American Heart Association guidelines was associated with increased preoperative myocardial scanning (44.3% vs 20.6%; P < 0.05) and coronary revascularization (7.7% vs 0.8%; P < 0.05). During the intervention period, there was a significant decrease in the incidence of cardiac complications (from 11.3% to 4.5%) and an increase in event-free survival at 1 yr after surgery (from 91.3% to 98.2%). Multivariate regression analysis showed that the combined administration of clonidine and beta-blockers was associated with a decreased risk of cardiovascular events (odds ratio, 0.3; 95% confidence interval, 0.1-0.8), whereas major bleeding, renal insufficiency, and chronic obstructive pulmonary disease were predictive of cardiac complications. In conclusion, cardiac testing was helpful to identify a small subset of high-risk patients who might benefit from coronary revascularization. Sequential and selective antiadrenergic treatments were associated with improved postoperative cardiac outcome. IMPLICATIONS: Implementation of American College of Cardiology/American Heart Association guidelines and use of antiadrenergic drugs were associated with better cardiac outcomes after major vascular surgery.     

Prävention perioperativer Myokardischämien – ein Update

Perioperative cardiac morbidity and mortality are a major health care challenge with important individual as well as economic aspects. Up to 30% of all perioperative complications and up to 50% of all postoperative deaths are related to cardiac causes. Perioperative myocardial ischemia, which occurs in more than 40% of patients with or at risk for coronary artery disease and undergoing noncardiac surgery, represents a dynamic predictor of postoperative cardiac complications. Long-duration myocardial ischemia and ischemic episodes associated with myocardial cell damage are particularly of prognostic relevance. In patients suffering from this type of ischemia, the incidence of adverse cardiac outcome is increased up to 20-fold. Reducing the incidence of perioperative myocardial ischemia is associated with a decrease in adverse cardiac outcome. Important issues related to perioperative myocardial ischemia are hematocrit level, body temperature, and hemodynamic variables. In contrast, the choice of anesthetic agents and techniques appears to be less important. Perioperative administration of anti-ischemic drugs in patients at risk, however, leads to a further decrease in the incidence of myocardial ischemia and to an improvement in patient outcome. Recent studies suggest that alpha 2-agonists and particularly beta-adrenoreceptor blocking agents are effective anti-ischemic drugs in the perioperative setting. Perioperative administration of beta-adrenoreceptor blocking agents in coronary risk patients undergoing noncardiac surgery is associated with a reduced rate of postoperative cardiac complications and an improvement in long-term outcome. This is particularly relevant in high risk patients with preoperative stress-induced ischemic episodes. In clinical practice, therefore, chronically administered anti-ischemic drugs should also be administered on the day of surgery and during the postoperative period. In untreated patients with or at risk for coronary artery disease and who have to undergo urgent surgical procedures without the opportunity of preoperative anti-ischemic intervention, perioperative administration of beta-adrenoreceptor blocking agents is mandatory.