ACC/AHA 2004 Guideline Update for Coronary Artery Bypass Graft Surgery: Summary Article

Percutaneous coronary intervention for myocardial infarction with left ventricular dysfunction

Patients who have had a myocardial infarction (MI) are at high risk for developing left ventricular dysfunction (LVD), which predisposes them to heart failure and is associated with an increased mortality risk. Early coronary revascularization, either with percutaneous coronary intervention or coronary artery bypass graft surgery, plays an important role in the preservation and restoration of left ventricular function after MI. This article discusses the effects of primary and nonemergent percutaneous coronary revascularization procedures on survival, left ventricular function, and the occurrence of complications, such as recurrent MI and stroke, compared with the effects of thrombolytic therapy. In addition, this article describes rescue revascularization procedures for patients who failed thrombolysis and those presenting relatively late or with negative electrocardiographic findings. Advanced interventional techniques, such as percutaneous ventricular assist devices and bioabsorbable stents, are very promising and may potentially help improve the outcomes of post-MI patients with LVD; however, the use of these techniques requires further validation.

Intramyocardial injection of autologous bone marrow cells as an adjunctive therapy to incomplete myocardial revascularization--safety issues

OBJECTIVES

To determine the safety of intramyocardial injection of autologous bone marrow cells in patients undergoing surgical myocardial revascularization (CABG) for severe coronary artery disease.

INTRODUCTION

There is little data available regarding the safety profile of autologous bone marrow cells injected during surgical myocardial revascularization. Potential risks include arrythmias, fibrosis in the injected sites and growth of non-cardiac tissues.

METHODS

Ten patients (eight men) were enrolled; they were 59+/-5 years old with limiting angina and were non-optimal candidates for complete CABG. Bone marrow cells (1.3+/-0.3x10(8)) were obtained prior to surgery, and the lymphomonocytic fraction (CD34+ =1.8+/-0.3%) was separated by density gradient centrifugation. During surgery, bone marrow cells were injected in non-grafted areas of ischemic myocardium. During the first year after surgery, the patients underwent laboratory tests, cardiac imaging, and 24-hour ECG monitoring.

RESULTS

Injected segments: inferior (n=7), anterior (n=2), septal (n=1), apical (n=1), and lateral (n=1) walls. Except for a transient elevation of C-reactive protein at one month post-surgery (P=0.01), laboratory tests results were within normal ranges; neither complex arrhythmias nor structural abnormalities were detected during follow-up. There was a reduction in functional class of angina from 3.6+/-0.8 (baseline) to 1.2+/-0.4 (one year) (P<0.0001). Also, patients had a significant decrease in the ischemic score assessed by magnetic resonance, not only globally from 0.65+/-0.14 (baseline) to 0.17+/-0.05 (one year) (P=0.002), but also in the injected areas from 1.11+/-0.20 (baseline) to 0.34+/-0.13 (one year) (P=0.0009).

CONCLUSIONS

Intramyocardial injection of bone marrow cells combined with CABG appears to be safe. Theoretical concerns with arrhythmias and/or structural abnormalities after cell therapy were not confirmed in this safety trial.

Effects of a waiting period after clopidogrel treatment before performing coronary artery bypass grafting

STUDY OBJECTIVE

To assess the effects of a waiting period after clopidogrel treatment before coronary artery bypass grafting (CABG). Design. Single-center, prospective, observational study.

SETTING

Cardiothoracic surgery intensive care unit at a university-affiliated medical center.

PATIENTS

One hundred consecutive patients who received clopidogrel and were scheduled to undergo primary CABG. In 64 of these patients, CABG was delayed at least 5 days after clopidogrel treatment (group A). The other 36 patients received clopidogrel treatment within 5 days of undergoing CABG (group B).

MEASUREMENTS AND MAIN RESULTS

Data were collected on patient demographics, time of last clopidogrel dose, preoperative anticoagulant and/or antiplatelet agents administered, surgical characteristics, intraoperative transfusions, blood products transfused, and chest tube output for 24 hours after surgery. No significant differences in baseline characteristics or intraoperative variables (number of bypasses, aortic cross-clamp time, and cardiopulmonary bypass time) were noted between the two groups. Mean +/- SD number of packed red blood cell units/patient was 1.1 +/- 1.4 in group A versus 2.1 +/- 2.5 in group B (p=0.009). Mean +/- SD number of platelet units/patient transfused was 0.5 +/- 0.9 in group A versus 1.9 +/- 1.6 in group B (p<0.001). When comparing a subset of 21 patients who received clopidogrel within 72 hours of surgery with the 64 whose CABG was delayed at least 5 days after clopidogrel treatment, the transfusion rates were significantly higher (95% vs 52%, p<0.05). Specifically, the mean +/- SD number of transfused units/patient of red blood cells (3.1 +/- 2.8 vs 1.1 +/- 1.4, p<0.005) and platelets (2.6 +/- 1.5 vs 0.5 +/- 0.9, p<0.007) was greater in patients who received clopidogrel within 72 hours of surgery.

CONCLUSION

A strategy to delay CABG after clopidogrel treatment led to reduced blood product administration. The optimal waiting period after clopidogrel treatment is not known but appears to be at least 5 days before CABG.

Traditional management of chronic stable angina

The clinical syndrome of chronic stable angina is an age-related condition that is one common manifestation of coronary artery disease (CAD). The presence of angina significantly affects quality of life when patients must limit their activities of daily living in an effort to prevent the occurrence of anginal attacks. In addition, patients are at risk for significant complications of CAD such as myocardial infarction, heart failure, stroke, and death. Therefore, treatment should focus not only on relief of symptoms and improvements in quality of life, but also on preventing disease progression and reducing the risk of complications from CAD. All patients should be instructed on the appropriate use of sublingual nitroglycerin for the immediate treatment of anginal episodes. Beta-blockers, calcium channel blockers, long-acting nitrate therapy, and ranolazine can prevent anginal symptoms. In addition, aggressive risk factor management, healthy lifestyle changes, antiplatelet agents such as aspirin, and angiotensin-converting enzyme inhibitors all should be used to prevent disease progression and occurrence of myocardial infarction or death. Many patients will be candidates for revascularization of the myocardium with either percutaneous coronary intervention or coronary artery bypass grafting for relief of symptoms as well as improvement in prognosis. Even after revascularization, patients may still require antianginal drug therapy. All patients undergoing revascularization should be guided to make appropriate lifestyle changes and to make concerted efforts to manage risk factors for CAD.

Postoperative atrial fibrillation

Atrial fibrillation is a common arrhythmia after cardiac surgery. It is associated with an increase in morbidity, length of hospital stay, and mortality. Patients who are at higher risk of postoperative atrial fibrillation should receive prophylactic treatment. Atrial fibrillation usually resolves spontaneously after heart rate is controlled; however, if patients are highly symptomatic or hemodynamically unstable, sinus rhythm should be restored by electrical or pharmacologic cardioversion. Patients with atrial fibrillation of more than 48 hours should receive antithrombotic therapy for thromboembolism prevention.

Hypoplastic left heart syndrome: consensus and controversies in 2007

Variability in practice can be considered to foster clinical innovation, and allow for individualized therapeutic plans and independence of practitioners. The Institute of Medicine, however, has issued a report suggesting that variability in patterns of practice are "illogical", and should be avoided whenever possible. Perhaps nowhere in the field of congenital cardiac disease is variability in practice more apparent than in the management of hypoplastic left heart syndrome. This review assesses the variability in practice at a large number of centres that manage neonates with hypoplastic left heart syndrome, with an emphasis on practice before, during, and after the first stage of the Norwood sequence of operations. We also suggest changes in future strategies for research. In March, 2007, colleagues were contacted to respond to an internet-based survey using commercially available software (www.surveymonkey.com) to collect responses about the management practices for neonates with "straight-forward" hypoplastic left heart syndrome. No attempt was made to correlate management practices with any measures of outcome, as neither the practices themselves, nor the outcomes of interest, could be externally validated. Data is reported from 52 centers thought to manage over 1000 neonates with hypoplastic left heart syndrome on an annual basis. The first stage of the Norwood sequence was "recommended" to families by approximately five-sixths (86.5%) of the centres. No centre recommended primary cardiac transplantation, a "hybrid" approach, or non-intervention. In 7 centres (14.5%), it was reported that there was discussion of some or all of the above options, but ultimately the families decided upon the appropriate strategy. Most centres preferentially used antegrade cerebral perfusion (54%) in contrast to deep hypothermia with circulatory arrest (24%), albeit that 11% of centres used a combination of these techniques and in 9% the support strategy was based on surgeon preference. The source of flow of blood for the lungs following the first stage of reconstruction was also highly variable. Of the 51 centres that responded to the question, 13 (25.5%) were participating in a multi-centric randomized clinical trial comparing the modified Blalock-Taussig shunt to the conduit placed from the right ventricle to the pulmonary arteries, the so-called "Sano" modification. Of the remaining 38 centres, 18 "usually" placed a conduit from the right ventricle to the pulmonary artery, 14 "usually" placed a modified Blalock-Taussig shunt, and at six centres, the decision was made "based upon the preference of the surgeon and/or the cardiologist". Similarly, significant variability in practice was evident in preoperative management, other surgical strategies, postoperative medical support, monitoring and discharge planning. Other than the randomized clinical trial of shunt type, no other medical or surgical management strategy was currently under investigation in a multi-centric or randomized trial in the centres who responded to the survey. The survey emphasises the extreme variability in our current practices for treatment of children with hypoplastic left heart syndrome. While there are some areas for which there is consensus in management, the majority of our practices are variable between and within centres. These results emphasize that large multicentric trials and registries are necessary to improve care, and to answer important clinical questions, emphasizing the need to shift from analysis of experiences of single centres to multi-centric and multi-disciplinary collaboration.

Simple Index to Predict Likelihood of Skilled Nursing Facility Admission After Coronary Artery Bypass Grafting Among Older Patients

BACKGROUND

Acceptable short-term mortality rates for elderly patients undergoing coronary artery bypass grafting (CABG) are reported in the literature. However, rather than death, older patients considering CABG are generally most concerned about a postoperative loss of functional independence. To address this concern, we describe an index that predicts a patient's likelihood of admission to a skilled nursing facility (SNF) after CABG.

METHODS

Logistic regression analysis of the California hospital discharge database during a 5-year period was performed to identify the most prevalent preoperative International Classification of Disease, 9th Revision Clinical Modification (ICD-9-CM) diagnoses associated with SNF admission after primary CABG in patients aged 65 years or older. Each diagnosis was weighted according to odds ratios to develop an index that predicts the likelihood of discharge to a SNF. The index was validated using our institutional database.

RESULTS

A total of 26,040 patients (mean age, 74.2 years; 67.2% men) fit our criteria. They had an in-hospital mortality rate of 3.09% and a 17.3% SNF discharge rate. Our index was a summation of nine selected preoperative ICD-9-CM diagnoses, which were assigned a value of 1 point (osteoarthritis, congestive heart failure, atrial fibrillation, myocardial infarction, anemia, obesity) or 2 points (female, chronic obstructive pulmonary disease, renal failure). Validation analysis produced a C statistic and pseudo r2 value of 0.6435 and 0.0408, respectively. Cut-point analysis suggests that patients with scores of 3 or higher can be considered "high-risk."

CONCLUSIONS

We describe a simple index to identify older patients at low-risk and high-risk for SNF admission after CABG. Such tools may be useful in counseling older patients considering CABG.

Usefulness of RISKO Heart Hazard Appraisal to Quantify CAD risk factor burden on the preoperative functioning of coronary artery bypass graft surgery patients

The preoperative status of coronary artery bypass graft (CABG) surgical patients is often evaluated as a means to assess operative risk for mortality and morbidity and to inform how preoperative status influences or predicts outcomes following CABG surgery. The purpose of this study was to examine the influence of coronary artery disease (CAD) risk factor burden on CABG patients' preoperative functioning (functional status and functional capacity). A convenience sample of 152 subjects, 65 years and older, who had been consecutively enrolled in a larger randomized clinical trial, was evaluated. The RISKO Heart Hazard Appraisal was used to quantify CAD risk factor burden of the subjects. There were significant differences by CAD risk factor burden group, with subjects in the highest CAD risk factor burden group having poorer general health functioning (F2,147=3.45; P<.05) and functional capacity (F2,147=5.43; P<.01). These findings elucidate the potential usefulness of evaluating CABG patients' preoperative CAD risk factor burden status.

Valor predictivo del modelo EuroSCORE en la cirugía cardíaca de nuestro centro

OBJECTIVE

The use of risk prediction models in cardiac surgery makes it possible to compare and evaluate health care quality between different institutions in countries. This study aimed to assess the performance of the European System for Cardiac Operative Risk Evaluation (EuroSCORE) model in estimating the risk of mortality of cardiac surgery patients of our hospital.

PATIENTS AND METHODS

The additive and logistic EuroSCORE models were applied to all patients who underwent cardiac surgery with extracorporeal circulation from the time the cardiac surgery unit was opened in our center in November 2002 until February 2006. All data were obtained prospectively when the patients were admitted to the Intensive Care Unit. Mortality observed was compared with that estimated in the following subgroups: global cardiac surgery, isolated coronary surgery, isolated valvular surgery, combined valvular and coronary surgery and thoracic aorta surgery. Model discrimination was tested by determining the area under the receiver operating characteristic (ROC) curve.

RESULTS

We studied 1,053 patients who had several differences with the EuroScore model population. Overall observed mortality was 2.2% (95% CI 1.2 - 3.1). The EuroSCORE models overestimated mortality (additive predicted 5%, logistic predicted 4.6%). Mortality of coronary bypass graft surgery was 1.2% and both EuroSCORE models overestimated it. Discriminative power of both models was good with an Area under ROC curve for both models of 0.78 and 0.79.

CONCLUSIONS

The use of both EuroSCORE models overestimated overall observed mortality and that of the different surgical subgroups of cardiac surgery performed in our institution.

Mediastinitis following coronary artery bypass graft surgery: pathogenesis, clinical presentation, risks, and management

The incidence of mediastinitis following coronary artery bypass graft surgery is less than 5%; however, this devastating complication results in significant mortality and morbidity. Reoperation, prolonged ventilation, increased length of stay in intensive care unit, and extensive wound treatments contribute to patient, family, and institutional burdens. Modifiable risk factors should be corrected whenever possible. Adherence to evidence-based guidelines for the prevention of deep surgical site infections is essential. In addition, recognition and aggressive clinical management of this life-threatening condition have been found to improve patient outcomes. The purpose of this article is to review the pathophysiology, clinical presentation, perioperative risk factors, and current treatment recommendations for mediastinitis following coronary artery bypass graft surgery.

Coronary artery bypass surgery in elderly people

An increasing number of elderly individuals are now undergoing coronary artery bypass surgery. Elderly patients, compared with patients of a younger age group, present for surgery with a greater burden of risk factors and reduced functional levels. Short-term outcomes are hence poorer in them. But symptom relief occurs in most survivors and is accompanied by excellent rates of long-term survival and a good quality of life. Therefore, an individualised risk-benefit profile must be carefully constructed by clinicians, taking into account several different factors and not just age alone. This review summarises the current concepts of coronary artery bypass surgery from the perspective of the very old.

Outcomes Associated With the Use of Secondary Prevention Medications After Coronary Artery Bypass Graft Surgery

BACKGROUND

Secondary prevention medications are beneficial after acute coronary syndromes, but these benefits are less clear after coronary artery bypass graft surgery. We investigated whether greater use of secondary prevention medications after coronary artery bypass graft surgery is associated with improved clinical outcomes.

METHODS

Patients undergoing coronary artery bypass graft surgery in the PREVENT IV trial (n = 2970) were surveyed for use of antiplatelet agents, beta-blockers, angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, and lipid-lowering agents after hospital discharge and at 1 year. Patients were categorized based on their percentage use of indicated medications after hospital discharge. Cox modeling was used to determine the association between medication use categories and rates of death or myocardial infarction through 2 years after adjustment for clinical factors, the number of indicated medications, and treatment propensity.

RESULTS

Rates of use of antiplatelet agents and lipid-lowering agents were high at discharge and at 1 year, but use of beta-blockers and angiotensin-converting enzyme inhibitors or angiotensin receptor blockers was suboptimal. There was a stepwise association between medication use at discharge and patient outcomes (p for trend = 0.014). Patients taking 50% or less of indicated medications at discharge had a significantly higher 2-year rate of death or myocardial infarction (8.0% versus 4.2%; adjusted hazard ratio, 1.69; 95% confidence interval, 1.12 to 2.55; p = 0.013) than those taking all indicated medications.

CONCLUSIONS

Greater use of indicated secondary prevention medications after coronary artery bypass graft surgery is associated with a lower 2-year rate of death or myocardial infarction. These data underscore the importance of appropriate secondary prevention measures to improve long-term clinical outcomes after coronary artery bypass graft surgery.

Risk-Stratified Evaluation of Amiodarone to Prevent Atrial Fibrillation After Cardiac Surgery

BACKGROUND

Amiodarone prophylaxis (AMP) reduces the prevalence of postoperative atrial fibrillation (POAF) after cardiac surgery. We investigated the impact of AMP on the frequency and duration of POAF, the intensive care unit and hospital length of stay, and its cost-effectiveness in a risk-stratified cohort.

METHODS

A retrospective, observational analysis of 509 patients who underwent cardiac surgery in 2003 was performed. Data sources included The Society of Thoracic Surgeons national database; medical and medication administration records; and the activity-based cost data from our institution. Risk stratification for POAF was determined using a validated risk index. Cost-effectiveness was determined from the hospital's perspective.

RESULTS

The mean patient age was 63 years, 27% were female, 80% underwent coronary artery bypass grafting, and 29% underwent valve surgery. When a risk-stratified evaluation was made, 50% of patients were at an elevated risk for having POAF develop. When compared with nonprophylaxed patients, those receiving AMP (59%) experienced less POAF (31% vs 22%; p = 0.027) and shorter durations of POAF (4.7 vs 2.7 days; p = 0.025). In the elevated-risk group, AMP clinically (but not significantly) reduced length of stay in the intensive care unit (101 vs 68 hours; p > 0.05) and post-procedural hospital length of stay (9.7 vs. 7.9 days, p > 0.05). In the elevated-risk group, AMP was robustly cost-effective in reducing POAF.

CONCLUSIONS

Amiodarone prophylaxis reduced the prevalence and duration of POAF. Baseline risk for POAF was a major determinant of the overall cost-effectiveness of AMP. The greatest cost savings with AMP was seen in patients at an elevated risk for POAF. These findings suggest the need for risk stratification when prescribing AMP.

Gender-specific practice guidelines for coronary artery bypass surgery: perioperative management

Gender differences in coronary bypass surgery have been the focus of numerous publications in recent years. Unfortunately these publications have contradictions that leave surgeons with conflicting recommendations for care. To help resolve these inconsistencies, The Society of Thoracic Surgeons (STS) Workforce on Evidence-Based Surgery has carried out an objective review of published information in this field. The STS Workforce recognizes that there are important gender issues associated with referral bias, the impact of body size, psychosocial factors, and postoperative support, but the intent of this guideline is to focus specifically on perioperative management. As with all practice guidelines, our goal is to gather the most important information, analyze the information in a logical and unbiased fashion, and make recommendations based solely on the available evidence.

Coronary artery revascularization: past, present, future: part II--newer technologies

Advances in coronary artery revascularization have been accompanied by clinical trials evaluating these advances. Part I of this paper addressed historic trials related to coronary artery revascularization. This paper reviews the data supporting newer revascularization strategies for our patients, including drug-eluting stents and off-pump coronary artery bypass surgery. Benefits include reduced repeat revascularization in patients who undergo percutaneous treatments with drug-eluting stents, the durability of surgical arterial revascularization, and the importance of medical therapy as the mainstay of treatment.

Relationship of Atrial Fibrillation and Stroke After Coronary Artery Bypass Graft Surgery: When is Anticoagulation Indicated?

BACKGROUND

Atrial fibrillation (AF) is considered as a risk factor for stroke after coronary artery bypass grafting operations.

METHODS

A retrospective search in our hospital's medical record database was done to identify patients with postoperative strokes who underwent coronary artery bypass grafting operations from January 1, 1993, until December 31, 2004. All cases were individually reviewed, and the temporal relationship between neurologic event and postoperative episodes of AF was determined. During the study period it was our consistent policy to use only Coumadin anticoagulation limited to patients who had persistent AF or were to be discharged in AF.

RESULTS

Of the 2,964 coronary artery bypass grafting operations, 576 patients (19.4%) had AF and 32 patients (1.1%) suffered stroke. Seventeen stroke patients maintained normal sinus rhythm during their hospital stay. Of the remaining 15 patients, 9 presented with neurologic deficit before the first episode of AF, with 5 having intraoperative and 4 having postoperative stroke. Of the 6 patients with AF before neurologic event, three strokes occurred within 1 week after spontaneous conversion to normal sinus rhythm. One patient with preoperative and also with intraoperative AF who underwent emergency coronary artery bypass grafting woke up with stroke. In the remaining two cases, the AF or atrial flutter episodes lasted less than 6 hours each before the neurologic event. More aggressive anticoagulation as suggested in the published guidelines could not have prevented strokes in any of these 6 patients.

CONCLUSIONS

This retrospective analysis does not support the use of aggressive anticoagulation, particularly full intravenous heparinization as a bridging therapy to decrease the already low incidence of postoperative strokes after routine coronary artery bypass grafting surgery.

An examination of factors influencing the choice of therapy for patients with coronary artery disease

Background

A diverse range of factors influence clinicians' decisions regarding the allocation of patients to different treatments for coronary artery disease in routine cardiology clinics. These include demographic measures, risk factors, co-morbidities, measures of objective cardiac disease, symptom reports and functional limitations. This study examined which of these factors differentiated patients receiving angioplasty from medication; bypass surgery from medication; and bypass surgery from angioplasty.

Methods

Univariate and multivariate logistic regression analyses were conducted on patient data from 214 coronary artery disease patients who at the time of recruitment had been received a clinical assessment and were reviewed by their cardiologist in order to determine the form of treatment they were to undergo: 70 would receive/continue medication, 71 were to undergo angioplasty and 73 were to undergo bypass surgery.

Results

Analyses differentiating patients receiving angioplasty from medication produced 9 significant univariate predictors, of which 5 were also multivariately significant (left anterior descending artery disease, previous coronary interventions, age, hypertension and frequency of angina). The analyses differentiating patients receiving surgery from angioplasty produced 12 significant univariate predictors, of which 4 were multivariately significant (limitations in mobility range, circumflex artery disease, previous coronary interventions and educational level). The analyses differentiating patients receiving surgery from medication produced 14 significant univariate predictors, of which 4 were multivariately significant (left anterior descending artery disease, previous cerebral events, limitations in mobility range and circumflex artery disease).

Conclusion

Variables emphasised in clinical guidelines are clearly involved in coronary artery disease treatment decisions. However, variables beyond these may also be important factors when therapy decisions are undertaken thus their roles require further investigation.

Recent developments in beta-blockers and anaesthesia

PURPOSE OF REVIEW

To evaluate developments on the subject of beta-blockers and anaesthesia published in the past 12 months. The administration of beta-blockers has been established as a pharmacological approach to reduce cardiac events in the perioperative period. A number of studies and reviews have been published underlining the appropriateness of this approach in patients undergoing non-cardiac as well as cardiac surgery. A lack of transfer of the scientific knowledge to clinical practice is evident not only in the field of perioperative medicine, which results in an under-use of beta-blockers. Open questions are still directed towards the optimal dosage, the effectiveness of chronic beta-blockade and the effects of beta-blockade in traumatized and burned patients.

RECENT FINDINGS

Progress in the use of beta-blockers has been realized by the introduction of institutional protocols. In chronic beta-blockade a simple continuation does not provide effective protection. Improved protection might be gained by the combination of beta-blockers and statins in high-risk patients. The role of beta-blockers in pain management is currently a field of interest, although there seem to be many open questions. There are still doubts about the evidence of perioperative beta-blockade: the results of large trials will be published in the next 2 years. The approach is cost-effective: a comparison with other alternative approaches to cardioprotection is pending.

SUMMARY

There has been significant progress in the use of perioperative beta-blockade. Although a considerable amount of knowledge is obvious, the optimal strategy in different clinical settings is still a matter of debate.

How to revascularize patients with diabetes mellitus: bypass or stents and drugs?

The diabetic patient is at high risk for coronary artery disease. Incidence as well as severity of the disease is highly increased in comparison to non-diabetic patients. The revascularization of the diabetic patient is a great challenge, since the longterm results are disappointing when compared to non-diabetic patients. The success of coronary artery bypass grafting is limited by increased perioperative mortality and a faster occlusion of especially venous bypass grafts. In percutaneous interventions the excessive high restenosis rates worsen longterm results. Several clinical trials investigated the outcome of the two revascularization strategies and could demonstrate at least a tendency towards better results when the operative approach was chosen. Particularly, the BARI trial showed reduced mortality for surgery when compared to percutaneous coronary interventions. However, in this trial, in 87% of patients undergoing bypass surgery all stenoses were successfully treated, whereas in patients undergoing percutaneous coronary intervention only 76% of all stenoses were primarily successfully treated. In addition, no stents were used in this trial.Furthermore, the enrollment of the previous trials dates one decade ago. These trials do therefore not necessarily represent the current standard therapy, especially for percutaneous coronary interventions. The restenosis rate could be decreased in recent years by means of drug-eluting stents and an aggressive antiplatelet therapy from more than 50% to less than 10% leading to considerably improved long-term results. Therefore, percutaneous coronary interventions have developed to be a reasonable alternative to bypass surgery. Different clinical trials are currently underway (BARI 2D, CarDIA, FREEDOM) comparing the outcome of the two approaches.

Improved survival in asymptomatic diabetic patients with high-risk SPECT imaging treated with coronary artery bypass grafting

BACKGROUND

The Bypass Angioplasty Revascularization Investigation trial demonstrated that symptomatic diabetics with multivessel coronary artery disease had a survival advantage with initial coronary artery bypass grafting (CABG) versus percutaneous coronary intervention (PCI). No published study has examined different treatments and outcome in asymptomatic diabetics.

METHODS AND RESULTS

This study group consisted of 826 asymptomatic diabetics (age 62+/-12 years; 76% men) without known coronary artery disease who had abnormal myocardial perfusion during stress single photon emission computed tomography (SPECT). SPECT images were classified as low-, intermediate-, and high-risk. Early revascularization (CABG or PCI < or =4 months after SPECT) was performed in 76 patients. Survival (follow-up, 5.3+/-3.3 years) was compared in patients treated with CABG, PCI, or medical therapy. Revascularization (CABG or PCI) was performed in 54 of 261 patients with high-risk scans and was independently associated with improved survival (chi2=4.55; P=0.03 after multivariate adjustment). Subset analysis demonstrated that the survival advantage was confined to patients treated with CABG (n=39), with a 5-year survival CABG at 85%, PCI at 72%, and medical therapy at 67% (P=0.02 for 3 groups). Although CABG was associated with better survival, mortality remained high (3% per year). There was no survival advantage by treatment for patients with less-severe SPECT abnormalities.

CONCLUSIONS

These nonrandomized data suggest that CABG improves survival in asymptomatic diabetic patients with high-risk SPECT, although revascularization was performed infrequently in these patients. These results parallel those of the Bypass Angioplasty Revascularization Investigation trial in symptomatic diabetic patients.

Adding clopidogrel to aspirin improves outcome in ST-elevation myocardial infarction patients receiving fibrinolytic therapy

Acute coronary syndromes result from the rupture of an atherosclerotic plaque with superimposed thrombosis. In an ST-elevation myocardial infarction, the thrombus occludes the coronary vessel, leading to an abrupt decrease in myocardial perfusion. The focus of initial management is the timely restoration of flow in the infarct-related artery via fibrinolytic therapy or percutaneous coronary intervention. Adjunctive therapy aimed at inhibition of platelets and the coagulation cascade is critical to establish and maintain vessel patency. Clopidogrel, an oral antiplatelet agent, has recently been shown to offer significant clinical benefit in STEMI (ST-elevation myocardial infarction) and is a welcome addition to standard fibrinolytic therapy.

Rapid online quantification of left ventricular volume from real-time three-dimensional echocardiographic data

AIMS

Determination of left ventricular (LV) volumes and ejection fraction (EF) from two-dimensional echocardiographic (2DE) images is subjective, time-consuming, and relatively inaccurate because of foreshortened views and the use of geometric assumptions. Our aims were (1) to validate a new method for rapid, online measurement of LV volumes from real-time three-dimensional echocardiographic (RT3DE) data using cardiac magnetic resonance (CMR) as the reference and (2) to compare its accuracy and reproducibility with standard 2DE measurements.

METHODS AND RESULTS

CMR, 2DE, and RT3DE datasets were obtained in 50 patients. End-systolic and end-diastolic volumes (ESV and EDV) were calculated from the 2DE images using biplane method of disks. ES and ED RT3DE datasets were analysed using prototype software designed to automatically detect the endocardial surface using a deformable shell model and calculate ESV and EDV from voxel counts. 2DE and RT3DE-derived volumes were compared with CMR (linear regression, Bland-Altman analysis). In most patients, analysis of RT3DE data required <2 min per patient. RT3DE measurements correlated highly with CMR (r: 0.96, 0.97, and 0.93 for EDV, ESV, and EF, respectively) with small biases (-14 mL, -6.5 mL, -1%) and narrow limits of agreement (SD: 17 mL, 16 mL, 6.4%). 2DE measurements correlated less well with CMR (r: 0.89, 0.92, 0.86) with greater biases (-23 mL, -15 mL, 1%) and wider limits of agreement (SD: 29 mL, 24 mL, 9.5%). RT3DE resulted in lower intra-observer (EDV: 7.9 vs. 23%; ESV: 7.6 vs. 26%) and inter-observer variability (EDV: 11 vs. 26%; ESV: 13 vs. 31%).

CONCLUSION

Semi-automated detection of the LV endocardial surface from RT3DE data is suitable for clinical use because it allows rapid, accurate, and reproducible measurements of LV volumes, superior to conventional 2DE methods.

Rate versus rhythm control strategies for AF

The safest long-term management strategy for elderly patients with persistent or recurrent episodes of atrial fibrillation (AF) is careful rate control with medications in conjunction with appropriate oral warfarin anticoagulation. Atrioventricular junctional ablation, with pacemaker implantation, may be necessary in patients who cannot have their rate controlled adequately, or have marked fluctuations in rate with standard medical therapies. Maintenance of sinus rhythm with repeat cardioversions, antiarrhythmic medications, device therapy, or atrial ablation approaches are appropriate to consider for younger patients and those elderly patients who suffer from substantial symptoms shown to be related directly to AF.

Clopidogrel and Bleeding After Coronary Artery Bypass Graft Surgery

BACKGROUND

There is evidence that clopidogrel (with or without aspirin) confers superior outcomes in patients with coronary artery disease. The purpose of this study is to review the effect of preoperative clopidogrel administration on clinical outcome, bleeding complications and resource utilization after coronary artery bypass graft surgery.

METHODS

Patient data were prospectively collected from 919 patients who had isolated coronary surgery during the period 2000 to 2003. Outcome comparisons were studied, firstly between patients who received preoperative clopidogrel with those who did not, and secondly between patients on clopidogrel only, aspirin only, both or neither medications.

RESULTS

Twenty-four patients (2.6%) were on clopidogrel only, 598 (65.1%) were on aspirin only, 61 (6.6%) were on both, and 236 (25.7%) were on neither. Clopidogrel (n = 85) versus no clopidogrel (n = 834): there were no significant differences in the off-pump patients. In the on-pump patients, the clopidogrel group had significantly increased bleeding (p = 0.02), blood transfused (p = 0.01), intensive care (p = 0.03), and hospital stays (p = 0.03). There were no significant differences in surgical reexploration, perioperative myocardial infarction, intraoperative balloon pump use, inotropic support or 30-day mortality. Clopidogrel versus aspirin versus both versus neither: patients on both clopidogrel and aspirin had significantly more postoperative bleeding than patients on aspirin alone or on neither medication.

CONCLUSIONS

The preoperative use of clopidogrel in patients undergoing coronary artery bypass graft surgery showed limited clinical benefits; however, its use significantly increased the risk of bleeding, blood transfusion, and resource utilization.

A heart failure specialist's perspective on cardiac surgery for heart failure

Aside from cardiac transplantation, ventricular assist devices, and the total artificial heart, cardiac surgery now also plays a major role in the overall management of the heart failure patient. For patients with heart failure, cardiac surgery has steadily moved from being a predominant rescue procedure (eg, aneursymectomy, rupture repair, transplantation) to surgical interventions that can prevent or delay the progression of cardiac dysfunction and failure; these operations now include coronary artery bypass surgery, ventricular restoration, and valvular repair/replacement. This article discusses the role and impact of these specific surgical interventions in the setting of ventricular dysfunction and heart failure.

Perioperative myocardial infarction—aetiology and prevention

Perioperative myocardial infarction (PMI) is one of the most important predictors of short- and long-term morbidity and mortality associated with non-cardiac surgery. Prevention of a PMI is thus a prerequisite for an improvement in overall postoperative outcome. The aetiology of PMI is multifactorial. The perioperative period induces large, unpredictable and unphysiological alterations in coronary plaque morphology, function and progression, and may trigger a mismatch of myocardial oxygen supply and demand. With many diverse factors involved, it is unlikely that one single intervention will successfully improve cardiac outcome following non-cardiac surgery. A multifactorial, step-wise approach is indicated. Based on increasing knowledge of the nature of atherosclerotic coronary artery disease, and in view of the poor positive predictive value of non-invasive cardiac stress tests, and the considerable risk of coronary angiography and coronary revascularization in high-risk patients, the paradigm is shifting from an emphasis on extensive non-invasive preoperative risk stratification to a combination of selective non-invasive testing and aggressive pharmacological perioperative therapy. Perioperative plaque stabilization by pharmacological means may be as important in the prevention of PMI as an increase in myocardial oxygen supply or a reduction in myocardial oxygen demand.