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。     

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.     

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.     

The value of preoperative pharmacologic stress testing before vascular surgery using ACC/AHA guidelines: a prospective, randomized trial

OBJECTIVE: To evaluate the validity of preoperative cardiac stress testing using clinical predictors from the American College of Cardiology/American Heart Association Guidelines on Perioperative Evaluation before Noncardiac Surgery in patients undergoing vascular surgery. DESIGN: Prospective, randomized pilot study. SETTING: Academic medical center. PARTICIPANTS: Patients undergoing elective abdominal aortic, infrainguinal, and carotid vascular surgery. INTERVENTIONS: After stratification by American College of Cardiology/American Heart Association (ACC/AHA) Guideline parameters, 99 patients were randomized to preoperative cardiac stress testing or to no stress testing and followed for up to 12 months postoperatively for adverse cardiac outcomes. MEASUREMENTS AND MAIN RESULTS: Before hospital discharge of 46 patients who underwent preoperative stress testing, 7 (15%) had inducible ischemia with no adverse postoperative cardiac outcomes, whereas only 1 (3%) of 39 patients (85%) with no ischemia had a nonfatal adverse cardiac outcome (p = not significant). Of 53 patients without preoperative stress testing, only 2 (4%) had a nonfatal adverse postoperative cardiac outcome. There were no cardiac deaths. At 12-month follow-up in 79 (80%) patients, there was 1 nonfatal adverse cardiac outcome (no stress test) and 1 cardiac death (abnormal stress test), reflecting a 1% 12-month cardiac morbidity and mortality. CONCLUSION: In this small prospective, randomized study evaluating the validity of preoperative cardiac stress testing using ACC/AHA Guidelines before major vascular surgery, preoperative cardiac stress testing offered no incremental value for determining postoperative adverse cardiac outcomes. Larger randomized clinical trials are needed to confirm these findings.     

Guidelines for perioperative cardiac evaluation from the American College of Cardiology/American Heart Association task force are effective for stratifying cardiac risk before aortic surgery

PURPOSE: We assessed whether the American College of Cardiology/American Heart Association (ACC/AHA) task force guidelines for perioperative cardiac evaluation could reliably stratify cardiac risk before aortic surgery. METHODS: We retrospectively applied the guidelines to a closed database, set up prospectively. The setting was a referral center in an institutional practice with hospitalized patients. The closed database included 133 patients who had a routine cardiac examination, which comprised an estimation of functional capacity and noninvasive testing, before aortic surgery. This cardiac evaluation led to the proposal of coronarography in 23 patients and to treating an underlying coronary artery disease in 21 patients (including three myocardial revascularizations). One patient died after myocardial revascularization, and two patients died of cardiac causes after aortic surgery. The algorithm of the ACC/AHA guidelines was applied independently by two investigators to each patient's file that was included in the existing database. The main outcome measure was a comparison between cardiac risk stratification with the ACC/AHA guidelines and the results of the routine cardiac evaluation. RESULTS: The ACC/AHA guidelines were successfully applied to all 133 files by the two investigators. After applying the algorithm, 73 patients were stratified as low cardiac risk, and 60 patients were stratified as high risk. The 21 patients who had undergone a preoperative coronary artery disease optimization were stratified as high risk by means of the ACC/AHA guidelines. The patients who died from cardiac causes were stratified as high risk by means of the ACC/AHA guidelines, whereas none of the patients stratified as low risk died during hospitalization. CONCLUSION: The ACC/AHA guidelines were effective in stratifying cardiac risk by using clinical predictors and an estimate of the physical capacity of the patient. Their use may allow a reduction in unnecessary noninvasive testing in patients stratified as being at low risk, while permitting the selection of all patients likely to benefit from preoperative coronary artery disease optimization.     

Cardiac assessment prior to vascular surgery: Is dipyridamole-sestamibi necessary?

Dipyridamole-sestamibi (PMIBI) is recommended prior to vascular surgery in patients with 1 Eagle criteria (Q waves, history of ventricular ectopy, diabetes, advanced age, and/or angina). To review our cardiac morbidity and mortality and the need for preoperative PMIBI, we reviewed 109 consecutive patients with a mean age of 59 years who underwent 145 elective major vascular procedures over a 1-year period. Seventy patients (with a mean of 0.8 Eagle criteria) underwent 92 vascular procedures without preoperative PMIBI and without coronary revascularization. Thirty-one patients (with a mean of 1.1 Eagle criteria) underwent 39 procedures without coronary revascularization following PMIBI, which showed reversible ischemia in seven and a fixed defect in 10; findings were normal in 14. Preoperative coronary bypass or angioplasty was limited to eight patients (14 procedures, mean of 1.6 Eagle criteria) who had unstable angina with (2 patients) or without (6 patients) acute myocardial infarction. There were four perioperative myocardial infarctions (2.8%), seven cardiac events overall (4.8%), and one cardiac death (0.7%). Three (43%) of the seven cardiac events occurred in patients with a normal scan or fixed defect on PMIBI imaging. In the absence of unstable angina, PMIBI had a sensitivity of only 25% and a specificity of 80% of cardiac events. We conclude that among patientswithout severe cardiac symptoms (1) PMIBI has a very limited ability to identify patients at risk for cardiac complications, and (2) preoperative PMIBI is neither necessary nor cost-effective.Supported in part by a grant from the Harbor-UCLA Medical Center Research and Education Institute.Presented at the Fourteenth Annual Meeting of the Southern California Vascular Surgical Society, September 15–17, 1995, La Jolla, Calif.     

Ischemic heart disease

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

Cardiac complications after elective major vascular surgery

Cardiac complications are the major cause of perioperative and late mortality and morbidity in patients undergoing elective major vascular surgery. This review focuses on the pathophysiology of perioperative complications, risk assessment and risk reduction strategies, all related to cardiovascular disease. Patients without cardiac risk factors are considered to be at low risk and no additional evaluation for coronary artery disease is recommended; β-adrenergic blockers may reduce perioperative cardiac events; patients with one or more risk factors represent an intermediate to high-risk population. β-Adrenergic blockers should be prescribed to all patients and coronary revascularization should be reserved for patients who have a clearly defined need for revascularization independent of the need for vascular 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.     

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 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.     

Patients with positive preoperative stress tests undergoing vascular surgery

OBJECTIVE: To examine the perioperative cardiac morbidity and mortality in patients undergoing major vascular surgery with beta-blockade after a positive stress test or cardiac catheterization. DESIGN: Retrospective review of a quality assurance database. SETTING: A university teaching hospital. PARTICIPANTS: A consecutive series of 31 patients undergoing peripheral vascular or aortic surgery after a positive stress test or catheterization between November 2001 and September 2003. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: All 31 patients had a preoperative positive stress test and/or cardiac catheterization, with 12 having multiple areas at risk for myocardial ischemia. None had an intervening coronary revascularization. Twenty-seven had at least one of the intermediate clinical predictors as defined by the American College of Cardiology and 7 had a left ventricular ejection fraction < 40%. Twenty-three patients had been on a beta-blocker and continued on it, while the remainder started on it de novo perioperatively. None of the patients suffered from myocardial infarction, congestive heart failure, or cardiac death perioperatively. CONCLUSIONS: This case series reports on the authors' experience with patients undergoing high-risk vascular surgery after a positive stress test or catheterization, but without an intervening coronary intervention. All patients received perioperative beta-blockade and had a very low adverse cardiac event rate. With reduction of adverse events by beta-blockade, the likelihood of a positive event may be reduced and the utility of the test in risk stratification may be questioned.     

Validation of an updated approach to preoperative cardiac risk assessment in vascular surgery

To validate a more selective approach to cardiac assessment which consisted of limiting stress testing and coronary revascularization to highly selected patients and limiting coronary revascularization to patients with severe cardiac symptoms, we compared two time periods (1994-1995 and 2000-2001) with respect to cardiac work-up and cardiac morbidity and mortality. Our method involved a retrospective review of patients undergoing vascular procedures from 2000 to 2001 at a single institution. In group 1 (2000-2001), 139 operations were performed on 120 patients. In group 2 (1994-1995), 145 procedures were performed on 109 patients. Preoperative stress testing was reduced from 42 patients (29%) in group 2 to 20 patients (14%) in group 1 (P < 0.01), and preoperative coronary artery bypass grafting was reduced from six (4.1%) to two (1.4%) (P < 0.28), respectively. Coronary angiography was unchanged: 8 (5.8%) patients in group 1 versus 11 (7.9%) patients in group 2 (P = NS). Two (1.4%) patients underwent percutaneous transluminal coronary angioplasty in group 1 and group 2. Cardiac event rates were similar: seven (5%) patients in both groups. Cardiac death was not significantly different: two (1.4%) in group 1 versus one (0.7%) in group 2. Cardiac morbidity and mortality after major vascular surgery remain the same despite using a more selective cardiac stress protocol.     

The role of coronary artery disease in complications of abdominal aortic aneurysm surgery

Coronary artery disease (CAD) is a major cause of morbidity and mortality after elective surgical repair of abdominal aortic aneurysm (AAA). The aim of this study was to determine the relationship between the extent of CAD observed in coronary angiograms (more than 50% stenosis) and the frequency of postoperative myocardial ischemic complications in a consecutive series of 84 patients who underwent elective AAA repair. Ninety-four percent of the patients with clinical evidence of CAD had significant disease as observed in coronary angiograms and eight patients had left main CAD. Seventy-two patients underwent AAA repair with a mortality rate of 1.4%; five patients had preliminary myocardial revascularization, and AAA surgery was not recommended for four patients because of severe cardiac disease. Postoperative myocardial ischemic complications occurred in 13.4% of the patients who had undergone surgery--almost exclusively in patients with clinical evidence of CAD. Both myocardial ischemia and preoperative intervention were more frequent in patients with double- or triple-vessel disease than in patients with less extensive disease. Patients with symptoms and with double- or triple-vessel CAD have a high risk of developing myocardial ischemia after AAA surgery. Preliminary myocardial revascularization may be beneficial in this group of patients.     

Pre‐operative coronary revascularization: an optimal therapy for high‐risk vascular surgery patients?

Cardiac complications are the leading cause of peri-operative morbidity and mortality of patients undergoing vascular surgery. This high incidence of cardiac complications is related to the presence of underlying coronary artery disease. The optimal treatment strategy for these high-risk patients, including the use of pre-operative coronary revascularization for the purpose of improving peri-operative and long-term cardiac outcomes, has been controversial for several decades. Recently, the results of the Coronary Artery Revascularization Prophylaxis (CARP) trial showed that in the short term there is no reduction in the number of post-operative myocardial infarctions, deaths or length of stay in the hospital, or in long-term outcomes in patients who underwent pre-operative coronary revascularization compared with patients who received optimized medical therapy. In this review, we summarize the role of pre-operative revascularization before elective vascular surgery using current evidence from the CARP trial and of those from published studies.     

Optimal timing of abdominal aortic aneurysm repair after coronary artery revascularization.

OBJECTIVE: The authors ascertained the optimal timing of repair of an abdominal aortic aneurysm (AAA) after coronary artery revascularization. SUMMARY BACKGROUND DATA: Cardiac events are the most common cause of death after elective repair of AAA. Preoperative coronary revascularization has significantly reduced postoperative cardiac complications after elective AAA repair. Currently, most patients undergo repair of asymptomatic AAA within 6 months after the coronary revascularization. METHODS: The authors performed a retrospective review of patients who underwent repair or scheduled repair of an asymptomatic AAA within 6 months after coronary artery bypass graft (CABG) between March 1988 and October 1993. RESULTS: There was no mortality in the group of patients (n = 14) who underwent repair of AAA simultaneously or within 14 days of coronary revascularization. In contrast, there was a significantly increased mortality rate of 3 of 9 (33%) in patients scheduled to undergo repair of the AAA more than 2 weeks after coronary revascularization (p < 0.05). All nonsurvivors died between 16 and 29 days after CABG, and died as a result of ruptured AAA. CONCLUSION: Elective AAA repair should be undertaken simultaneously or within 2 weeks of coronary artery revascularization because of an increased risk of postoperative AAA rupture seen after this time period. In addition, simultaneous or early postoperative AAA repair does not increase the overall operative risk.     

Prognostic value of cardiac troponins in elderly patients with hip fracture—a systematic review

Cardiac troponins can be elevated in cardiac ischemic conditions or other diseases such as pulmonary embolism or renal failure, where they may predict outcome. We hypothesized that cardiac troponins offer useful prognostic information regarding morbidity and mortality in elderly hip fracture patients undergoing surgical therapy. A literature review was conducted using PubMed and CINAHL plus with full text (EBSCOhost). Articles with original data relating troponins to prognosis in elderly hip fracture patients were reviewed. Studies with patients not undergoing surgery or undergoing elective or nonhip fracture surgery were excluded. Six papers met inclusion criteria. Troponin elevation was seen in 26.7–39 % of patients, while myocardial infarction, cardiac complications, and cardiac death occurred in ≤35 % troponin-positive patients in four of six studies. Several noncardiac factors were associated with elevated troponin including higher American Society of Anaesthesiologists score, current smoking, reduced mobility/activity level, lower hemoglobin, and living in residential care. Patients with elevated troponin had longer lengths of stay, increased risk for discharge to long-term care facilities, and higher mortality. Increased age, male sex, and higher American Society of Anaesthesiologists score were also associated with mortality. Elevated troponin can be used as a marker of increased morbidity/mortality in elderly hip fracture patients undergoing surgery, as hypothesized, even in the absence of cardiac complications. Perioperative troponin evaluation may be useful for risk stratification, but further studies are needed to clarify risks and benefits of such testing.     

An evaluation of existing risk stratification models as a tool for comparison of surgical performances for coronary artery bypass grafting between institutions

Objective: Risk stratification systems are used in cardiac surgery to estimate mortality risk for individual patients and to compare surgical performance between institutions or surgeons. This study investigates the suitability of six existing risk stratification systems for these purposes. Methods: Data on 5471 patients who underwent isolated coronary artery bypass grafting at two UK cardiac centres between 1993 and 1999 were extracted from a prospective computerised clinical data base. Of these patients, 184 (3.3%) died in hospital. In-hospital mortality risk scores were calculated for each patient using the Parsonnet score, the EuroSCORE, the ACC/AHA score and three UK Bayes models (old, new complex and new simple). The accuracy for predicting mortality at an institutional level was assessed by comparing total observed and predicted mortality. The accuracy of the risk scores for predicting mortality for a patient was assessed by the Hosmer-Lemeshow test. The receiver operating characteristic (ROC) curve was used to evaluate how well a system ranks the patient with respect to their risk of mortality and can be useful for patient management. Results: Both EuroSCORE and the simple Bayes model were reasonably accurate at predicting overall mortality. However predictive accuracy at the patient level was poor for all systems, although EuroSCORE was accurate for low to medium risk patients. Discrimination was fair with the following ROC areas: Parsonnet 0.73, EuroSCORE 0.76, ACC/AHA system 0.76, old Bayes 0.77, complex Bayes 0.76, simple Bayes 0.76. Conclusions: This study suggests that two of the scores may be useful in comparing institutions. None of the risk scores provide accurate risk estimates for individual patients in the two hospitals studied although EuroSCORE may have some utility for certain patients. All six systems perform moderately at ranking the patients and so may be useful for patient management. More results are needed from other institutions to confirm that the EuroSCORE and the simple Bayes model are suitable for institutional risk-adjusted comparisons.     

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.     

Late results of coronary bypass in patients with infrarenal aortic aneurysms. The Cleveland Clinic Study.

Cardiac catheterization was performed in a prospective series of 1000 patients under consideration for elective peripheral vascular reconstruction at the Cleveland Clinic from 1978-1982. Of these, 246 patients (mean age: 68 years) presented primarily because of infrarenal abdominal aortic aneurysms (AAA) and are eligible for subsequent evaluation 3-7 years (mean: 4.6 years) after entrance into the study. Severe, surgically correctable coronary artery disease (CAD) was documented in 78 patients (32%) in the AAA group, and 70 patients (28%) received myocardial revascularization with four fatal complications (5.7%). A total of 56 patients in this subset had staged aneurysm resection, usually during the same hospital admission after coronary bypass, with a single death (1.8%) caused by cerebral infarction. The overall operative mortality rate for 126 coronary and AAA procedures was 4%. A total of 59 additional patients (25%) died during the late follow-up interval, including 14 patients (5.9%) with cardiac events and eight patients (3.4%) with ruptured aneurysms. The cumulative 5-year survival rate (75%) and cardiac mortality rate (5%) after coronary bypass reflected traditional parameters (preoperative ventricular function, completeness of revascularization) and are nearly identical to the results calculated for patients having normal coronary arteries or only mild to moderate CAD. In comparison, the cumulative survival and cardiac mortality rates in a small subset of patients with severe, uncorrected coronary involvement currently are 29% (p = 0.0001) and 34%, respectively. These data support the conclusion that selected patients who require elective resection of AAA also warrant myocardial revascularization to enhance perioperative risk and late survival.