Guidelines and indications for coronary artery bypass graft surgery

Development of American Association for Thoracic Surgery Quality Gateway outcome models, analytics, and visualizations for quality assurance

OBJECTIVE

The study objective was to develop comprehensive quality assurance models for procedural outcomes after adult cardiac surgery.

METHODS

Based on 52,792 cardiac operations in adults performed in 19 hospitals of 3 high-performing hospital systems, models were developed for operative mortality (n = 1271), stroke (n = 895), deep sternal wound infection (n = 122), prolonged intubation (6182), renal failure (1265), prolonged postoperative stay (n = 5418), and reoperations (n = 1693). Random forest quantile classification, a method tailored for challenges of rare events, and model-free variable priority screening were used to identify predictors of events.

RESULTS

A small set of preoperative variables was sufficient to model procedural outcomes for virtually all cardiac operations, including older age; advanced symptoms; left ventricular, pulmonary, renal, and hepatic dysfunction; lower albumin; higher acuity; and greater complexity of the planned operation. Geometric mean performance ranged from .63 to .76. Calibration covered large areas of probability. Continuous risk factors provided high information content, and their association with outcomes was visualized with partial plots. These risk factors differed in strength and configuration among hospitals, as did their risk-adjusted outcomes according to patient risk as determined by counterfactual causal inference within a framework of virtual (digital) twins.

CONCLUSIONS

By using a small set of variables and contemporary machine-learning methods, comprehensive models for procedural operative mortality and major morbidity after adult cardiac surgery were developed based on data from 3 exemplary hospital systems. They provide surgeons, their patients, and hospital systems with 21st century tools for assessing their risks compared with these advanced hospital systems and improving cardiac surgery quality.

Precision Surgical Therapy for Adenocarcinoma of the Esophagus and Esophagogastric Junction

INTRODUCTION

To facilitate the initial clinical decision regarding whether to use esophagectomy alone or neoadjuvant therapy in surgical care for individual patients with adenocarcinoma of the esophagus and esophagogastric junction-information not available from randomized trials-a machine-learning analysis was performed using worldwide real-world data on patients undergoing different therapies for this rare adenocarcinoma.

METHODS

Using random forest technology in a sequential analysis, we (1) identified eligibility for each of four therapies among 13,365 patients: esophagectomy alone (n = 6649), neoadjuvant therapy (n = 4706), esophagectomy and adjuvant therapy (n = 998), and neoadjuvant and adjuvant therapy (n = 1022); (2) performed survival analyses incorporating interactions of patient and cancer characteristics with therapy; (3) determined optimal therapy as that predicted to maximize lifetime within 10 years (restricted mean survival time; RMST) for each patient; and (4) compared lifetime gained from optimal versus actual therapies.

RESULTS

Actual therapy was optimal in 61% of those receiving esophagectomy alone; neoadjuvant therapy was optimal for 36% receiving neoadjuvant therapy. Many patients were predicted to benefit from postoperative adjuvant therapy. Total RMST for actual therapy received was 58,825 years. Had patients received optimal therapy, total RMST was predicted to be 62,982 years, a 7% gain.

CONCLUSIONS

Average treatment effect for adenocarcinoma of the esophagus yields only crude evidence-based therapy guidelines. However, patient response to therapy is widely variable, and survival after data-driven predicted optimal therapy often differs from actual therapy received. Therapy must address an individual patient's cancer and clinical characteristics to provide precision surgical therapy for adenocarcinoma of the esophagus and esophagogastric junction.

Maintaining Quality in Lower Volume Cardiac Surgery: A Blueprint From a Military Program

Although there is a clear volume-outcome relationship in the field of cardiac surgery, the existence of high-performing programs with relatively low case volumes is well established. This report describes the programmatic and institutional processes in place at a lower volume cardiac surgery center in a US military hospital, which have been executed to optimally leverage available resources in the delivery of exemplary patient care. By implementing a highly collaborative practice, rigorous outcomes review, evidence-based standardized care pathways, consistent attending surgeon oversight for care delivery, careful case selection, and a mechanism for support from highly experienced outside cardiac surgeons, the cardiac surgery program at the authors' institution delivers care on par with its higher volume counterparts. A review of these practices and available supporting evidence may provide a model for other programs seeking success in this setting.

Reverse Saphenous Vein Homografts as Bypass Conduits: A Preliminary Report

Reverse saphenous vein homografts (RSVH) were needed in 16 patients during the past two years to offer a more thorough myocardial revascularization procedure since autogenous donor material was limited either because of previous surgeries or unuseable harvested conduits. All patients (11 men/5 women, mean age of 71.1 years) presented with severe coronary insufficiency. Nine patients were having reoperations after having previous successful operations (mean 6.9 years), and 2 were having third-time redo surgery about fifteen years after their initial procedures. RSVH were selected by ABO blood typing and were supported postoperatively by antiplatelet therapy. RSVH allowed additional bypass grafting in all patients and yielded an average of 4.1 grafts per patient. To minimize the operative risks, RSVH were mainly used for occluded targeted vessels or nondominant arteries. Three early deaths (less than thirty days) occurred from (1) progressive heart failure after emergent bypass and mitral valve repair for cardiogenic shock, (2) stroke after redo surgery, and (3) renal failure after urgent redo bypass. Although the mean follow-up was only 11.5 months, the remaining 13 patients have clinically improved. Five selected patients have been restudied with arteriography and have demonstrated successful revascularization, ie, patent internal mammary arteries (6/6) and autogenous venous grafts (5/5). However, 4/10 RSVH conduits were nonfunctional and the other 6 were patent.

RSVH are effective conduits for cardiovascular reconstruction with excellent immediate hemodynamic characteristics similar to those of autogenous veins. They have been extremely effective in patients with limited autogenous donor material and, in selected cases, when a quick source of bypass material is needed in an emergent fashion. While the initial patency rates have been acceptable, long-term follow-up is needed for comparative rates.

A case report of coronary-subclavian steal syndrome treated with carotid to axillary artery bypass

Coronary-subclavian steal syndrome results from atherosclerotic disease of the proximal subclavian artery causing reversal of flow in an internal mammary artery used as conduit for coronary artery bypass. This rare complication of cardiac revascularisation leads to recurrence of myocardial ischaemia. When feasible, subclavian angioplasty and/or stent placement can provide acceptable result for these patients. Vascular reconstruction through carotid to subclavian artery bypass has been the standard procedure of choice. Other interventions in literature include axilloaxillary bypass and subclavian carotid transposition. This case report describes the use of carotid axillary artery bypass for the treatment of coronary-subclavian steal syndrome.

Diagnosis and Management of Subclavian Artery Stenosis Prior to Coronary Artery Bypass Grafting in the Current Era

There are several approaches to managing subclavian artery stenosis (SAS) prior to coronary artery bypass grafting (CABG) with an intended internal thoracic artery (ITA) graft to the left anterior descending (LAD) artery. We herein review the incidence of and various diagnostic modalities for detecting SAS. Published relevant clinical studies from the interventional cardiovascular and cardiac surgical literature are summarized. Particular emphasis is placed on the efficacy of various approaches to the patient diagnosed with SAS prior to CABG. Stenting the subclavian artery prior to bypass surgery and using an in situ ITA is compared to using the ITA as a "free" graft. The incidence of restenosis after subclavian artery angioplasty or stenting is not trivial and has been reported to occur at a rate of 6% to 21%; however, the average rate of restenosis with stenting appears to be in the mid-teens. Subacute subclavian stent thrombosis or occlusion is exceptionally rare, suggesting that a percutaneous approach to SAS is reasonable prior to CABG. For patients requiring emergent revascularization, placement of a free ITA graft to the LAD appears to be a safe and durable treatment as patency rates are comparable to that of an in situ LITA to the LAD. In summary, although no randomized clinical trials address the optimal management of SAS prior to CABG, both percutaneous and surgical options appear to be safe and reasonably durable.

Nuclear Stress Testing in Elderly Patients

Stress myocardial perfusion imaging (MPI) plays an important role in the diagnostic and prognostic assessment of coronary artery disease (CAD) in patients of all age groups who are undergoing assessment prior to non-cardiac surgery. MPI may utilise exercise treadmill or pharmacological stress testing. While MPI has been evaluated in a wide variety of patient subpopulations, there are very limited data on its prognostic value in the elderly population, particularly those >75 years of age, who are making up an ever increasing proportion of the patient population. Because of the higher prevalence and greater severity of CAD in older patients, the sensitivity of noninvasive MPI increases with age, whereas specificity tends to decline. In addition, maximal aerobic exercise capacity tends to decrease with age, making it common practice for elderly patients being assessed for CAD to undergo pharmacological MPI to evaluate their cardiovascular risk. In this article, we review the literature with respect to cardiac risk estimation in elderly patients undergoing MPI, particularly with respect to making prognostic assessments prior to undergoing surgery. Current data allow for the proper application of stress MPI in the elderly population. Use of MPI facilitates identification of the severity and extent of ischaemia as well as left ventricular dilatation and systolic function in elderly patients undergoing non-cardiac surgery.

Treatment of Unprotected Left Main Coronary Artery Stenosis in the Drug-Eluting Stent Era

Coronary angiography is often inadequate for estimating the severity of ambiguous left main coronary artery (LMCA) stenoses. Our assessment of these lesions can be improved by the techniques of intravascular ultrasound and fractional flow reserve which provide indices of stenosis severity to enable the prediction of future events and planning of treatment. For patients requiring LMCA revascularization, coronary artery bypass graft (CABG) surgery has been gold standard for decades. However, this technique continues to be limited by factors such as periprocedural mortality, prolonged hospital stay and rehabilitation, and long-term graft patency. LMCA stenosis remains one of the few serious challenges for the interventional cardiologists and, in the bare metal stent era, the long-term results were not sufficient to replace CABG surgery, mainly because of the high restenosis rate. Drug-eluting stents (DES) have dramatically reduced the restenosis rate and early results in small series (approximately 300 patients in total) treated with DES in LMCA have been encouraging, especially for lesions at the ostium and in the left main shaft. Before changes are made in the guidelines for treatment, we must wait for a refinement in the technique and stent design used for bifurcational left main lesion and the results of randomized, specific multicenter studies (SYNTAX trial). It is likely that, for selected patients, LMCA stenosis will be regarded as an indication for PCI.

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.

Use of myocardial perfusion imaging to predict the effectiveness of coronary revascularisation in patients with stable angina pectoris

PURPOSE

Coronary revascularisation is the treatment of choice in patients with stable angina who have significant stenoses. From a pathophysiological point of view, however, mitigation of angina is to be expected only in the presence of reversible ischaemia. Therefore it was the aim of this study to examine the effect of revascularisation on stable angina in relation to the myocardial perfusion imaging (MPI) pattern prior to intervention.

METHODS

Three hundred and eighty-four patients (58.0+/-8.8 years) referred for angiography underwent MPI. Prior to MPI and at 2-year follow-up, patients were classified as having typical angina, atypical angina, non-cardiac chest pain or no pain, and the severity of chest pain was graded according to the Canadian Cardiovascular Society (CCS) criteria. The patients themselves estimated their pain on a visual analogue scale. Management was based on symptoms and angiographic findings, since the results of MPI were not communicated.

RESULTS

Among the 240 patients who were not revascularised, 79% had typical or atypical angina at study entrance versus 40% at follow-up. In comparison, 93% of the 144 revascularised patients had typical or atypical angina before intervention versus only 36% at follow-up. This additional advantage of invasive therapy was present only in patients with reversible defects; revascularisation had no additional effect in patients with normal perfusion or irreversible defects. Similarly, additional, significant reductions in CCS class and visual analogue score were observed exclusively in patients with reversible defects.

CONCLUSION

In patients referred for coronary angiography owing to known or suspected stable angina, revascularisation was significantly more effective than medical treatment exclusively in patients with reversible ischaemia.

Preventing recurrent events long term after coronary artery bypass graft: suboptimal use of medications in a population study

BACKGROUND

There are few population-based data on long-term management of patients after coronary artery bypass graft (CABG), despite the high risk for future major vascular events among this group. We assessed the prevalence and correlates of pharmacotherapy for prevention of new cardiac events in a large population-based series.

METHODS

A postal survey was conducted of 2500 randomly selected survivors from a state population of patients 6 to 20 years after first CABG.

RESULTS

Response was 82% (n = 2061). Use of antiplatelet agents (80%) and statins (64%) declined as age increased. Other independent predictors of antiplatelet use included statin use (odds ratio [OR] 1.6, 95% CI 1.26-2.05) and recurrent angina (OR 1.6, CI 1.17-2.06). Current smokers were less likely to use aspirin (OR 0.59, CI 0.4-0.89). Statin use was associated with reported high cholesterol (OR 24.4, CI 8.4-32.4), management by a cardiologist (OR 2.3, CI 1.8-3.0), and the use of calcium channel-blockers. Patients reporting hypertension or heart failure, in addition to high cholesterol, were less likely to use statins. Angiotensin-converting enzyme inhibitors were the most commonly prescribed agents for management of hypertension (59%) and were more frequently used among patients with diabetes and those with symptoms of heart failure. Overall 42% of patients were on angiotensin-converting enzyme inhibitors and 36% on beta-blockers.

CONCLUSIONS

Gaps exist in the use of recommended medications after CABG. Lower anti-platelet and statin use was associated with older age, freedom from angina, comorbid heart failure or hypertension, and not regularly visiting a cardiologist. Patients who continue to smoke might be less likely to adhere to prescribed medications.

Race and Gender Disparities in Rates of Cardiac Revascularization

BACKGROUND

Numerous studies have documented substantial differences by race and gender in the use of coronary artery bypass graft surgery and percutaneous coronary angioplasty. However, few studies have examined whether these differences reflect problems in quality of care.

METHOD

We selected a random sample stratified by gender, race, and income of 5026 Medicare beneficiaries aged 65 to 75 who underwent inpatient coronary angiography during 1991 to 1992 in 1 of 5 states. We compared the frequency of 2 problems in quality by race and gender: underuse or the failure to receive a clinically indicated revascularization procedure and receipt of revascularization when it was not clinically indicated. We used 2 independent sets of criteria developed by the RAND Corporation and the American College of Cardiology/American Hospital Association (ACC/AHA). We also examined survival of the cohort through March 31, 1994.

RESULTS

Revascularization procedures were clinically indicated more frequently among whites than blacks and among men than women. Failure to receive revascularization when it was indicated was more common among blacks than among whites (40% vs. 23-24%, depending on the criteria, both P<0.001) but similar among men and women (25% vs. 22-24%, P>0.05). Racial disparities remained similar after adjusting for patient and hospital characteristics. Among patients rated inappropriate, use of procedures was greater for whites than blacks using RAND criteria (10.5% vs. 5.8%, P<0.01) and greater for men than for women (14.2% vs. 5.3% by RAND criteria, P=0.001; 8.2% vs. 4.0%% by ACC/AHA criteria, P=0.04). After multivariate adjustment, the disparities for race and gender remained similar and were statistically significant using RAND criteria. Mortality rates tended to validate our appropriateness criteria for underuse.

CONCLUSIONS

Racial differences in procedure use reflect higher rates of clinical appropriateness among whites, greater underuse among blacks, and more frequent revascularization when it was not clinically indicated among whites. Underuse is associated with higher mortality. In contrast, men had higher rates of clinical appropriateness and were more likely to receive revascularization when it was not clinically indicated. There was no evidence of greater underuse among women.

Endovascular therapy in prevention and management of coronary-subclavian steal

BACKGROUND

The optimal management of patients undergoing coronary artery bypass grafting (CABG) who have proximal subclavian artery stenosis (SAS) is not well established. SAS may lead to flow reversal through a patent in situ internal mammary artery graft, resulting in myocardial ischemia (coronary-subclavian steal). We review our experience in prevention and management of coronary-subclavian steal.

METHODS

The medical records of patients who received treatment of symptomatic coronary-subclavian steal were reviewed. Patients who underwent subclavian artery revascularization before CABG were also included in our review. Patient demographic data, findings at presentation, imaging and treatment methods, and short-term and intermediate-term results were analyzed.

RESULTS

Over 4 years, 14 patients with combined subclavian and coronary artery disease were identified. Nine patients had angina (n = 8) and/or congestive heart failure (n = 2) after CABG (post-CABG group). Four patients underwent treatment of SAS and one underwent treatment of recurrent stenosis before or during CABG (pre-CABG group). Among this pre-CABG group, one patient had symptoms of left arm claudication; the other four patients had no symptoms. A blood pressure gradient was commonly noted between both arms. An angiogram confirmed the proximal location of SAS in all patients, and established the presence of flow reversal in a patent internal mammary artery graft in the post-CABG group. Operative management consisted of percutaneous transluminal angioplasty (PTA) and stenting of the subclavian lesion in 11 patients, PTA only in 2 patients, and carotid-subclavian bypass grafting in 1 patient. No known perioperative complications or morbidity was encountered in either group. Mean follow-up was 29 months, during which stenosis recurred in two patients, along with associated cardiac symptoms. In both patients repeat angioplasty was successful, for an assisted primary patency rate of 100%.

CONCLUSION

PTA and stenting to treat SAS appears to provide effective protection from and treatment of coronary-subclavian steal over the short and intermediate terms. A surveillance program is essential because of the risk for recurrent stenosis. Continued follow-up is necessary to determine long-term efficacy of this treatment compared with more conventional surgical approaches.

Clinical and six-month angiographic evaluation of coronary arterial graft interrupted anastomoses by use of a self-closing clip device: a multicenter prospective clinical trial

OBJECTIVES

To evaluate the safety and effectiveness of a self-closing surgical clip with an interrupted technique in left internal thoracic artery to left anterior descending artery bypass grafting.

METHODS

Eighty-two patients were enrolled and treated (February 2000 through August 2001) in a prospective, nonrandomized, multicenter trial. Left internal thoracic artery to left anterior descending artery anastomoses were performed in 60 off-pump coronary artery bypasses (73%), 12 conventional coronary artery bypass grafting (15%), and 10 minimally invasive direct coronary artery bypass (12%) procedures. Angiograms (64 to 383 days, mean 200 days) were obtained on 63 patients (77%). Qualitative and quantitative angiographic assessment was performed by an independent core laboratory.

RESULTS

The self-closing surgical clip was used for 82 left internal thoracic artery to left anterior descending artery interrupted anastomoses without the requirement for knot tying or primary suture management. Minimum left internal thoracic artery to left anterior descending artery anastomosis time was 3 minutes. There was one perioperative and one late death (both not heart related) and one reexploration for bleeding unrelated to the anastomotic site. FitzGibbon grades were as follows: A (n = 60, 95.2%), B (n = 3, 4.8%) including one kinked left internal thoracic artery, and O (n = 0, 0%). Quantitative analysis (n = 57) showed mean lumen diameters of left internal thoracic artery proximal to the anastomosis of 2.1 mm, at anastomosis of 2.0 mm, and in the left anterior descending artery distal to the anastomosis of 1.9 mm. The average ratio of the anastomosis to the left anterior descending artery diameter was 1.14 (0.45 to 1.93). Anastomotic stenosis as a percentage of average left internal thoracic artery to left anterior descending artery diameter was -2.3%, comparing favorably with results (23% to 24%) reported from the Patency, Outcomes, Economics, Minimally invasive direct coronary artery (POEM) bypass study.

CONCLUSIONS

The interrupted technique, facilitated by a self-closing anastomotic clip, yields favorable 6-month angiographic results when compared with other published studies.

Simultaneous coronary - subclavian and vertebral - subclavian steal syndrome

Atherosclerotic disease of the coronary artery may simultaneously involve the subclavian artery, and a significant stenosis of the left subclavian artery may result in recurrent myocardial ischemia in patients with patent left internal mammary artery (LIMA) grafts because of 'coronary steal' through the LIMA. Isometric exercise of the left arm may improve myocardial perfusion through vertebral - subclavian steal by flow reversal in the ipsilateral vertebral artery because of the change in the pressure gradient between the circle of Willis and the distal subclavian artery. The present patient had coronary steal through a LIMA after coronary artery bypass surgery and a transient vertebral - subclavian steal with improved myocardial perfusion as a result of exercise of the left arm.

Estimates of direct medical costs for microvascular and macrovascular complications resulting from type 2 diabetes mellitus in the United States in 2000

BACKGROUND

Diabetes mellitus is a chronic condition that affects the health of Americans and the US health care system on many levels. According to the American Diabetes Association, approximately 16 million Americans have diabetes mellitus. The onset of type 2 diabetes mellitus, which accounts for the vast majority (90%-95%) of cases, precedes diagnosis by a mean 7 years, with the disease typically manifesting during adulthood. It is not uncommon for people to first realize they have diabetes mellitus due to the appearance of a related complication.

OBJECTIVE

The goal of this analysis was to estimate the direct medical costs of managing microvascular and macrovascular complications of type 2 diabetes mellitus in the United States in the year 2000.

METHODS

Complication costs were estimated by applying unit costs to typical resource-use profiles. A combination of direct data analysis and cost modeling was used. For each complication, the event costs referred to those associated with the acute episode and subsequent care in the first year. State costs were the annual costs of continued management. Data were obtained from many sources, including inpatient, ambulatory, and emergency department care databases from several states; national physician and laboratory fee schedules; government reports; and literature. All costs were expressed in 2000 US dollars.

RESULTS

Major events (eg, acute myocardial infarction--30,364 dollars event cost, 1678 dollars state cost) generated a greater financial burden than early-stage complica- tions (eg, microalbuminuria--63 dollars event cost, 15 dollars state cost). However, complications that were initially relatively low in cost (eg, microalbuminuria) can progress to more costly advanced stages (eg, end-stage renal disease--37,022 dollars state cost).

CONCLUSIONS

Given the scope of diabetes mellitus in the United States and its impact on health care and budgets, it is important for policy makers to have up-to-date information about treatment outcomes and costs. The costs presented here provide essential components for any analysis examining the economic burden of the complications of diabetes mellitus.

Patient anxiety while on a waiting list for coronary artery bypass surgery: a qualitative and quantitative analysis

OBJECTIVE

The purpose of this study was to describe the nature and intensity of anxiety felt by patients awaiting coronary artery bypass surgery.

DESIGN

A prospective, cross-sectional study design was used, with a qualitative interview and State Trait Anxiety Inventory.

SETTING

Study took place in 2 large tertiary referral hospitals in Northern Ireland.

PARTICIPANTS

Seventy patients were randomly selected within 4 weeks of their referral for cardiac surgery.

RESULTS

Participants in this study cited 5 main sources of anxiety: chest pain, uncertainty, fear of the operation, physical incapacity, and dissatisfaction with the care offered to them. The State Trait Anxiety Inventory scores of this sample were high at all stages of data collection. There was a statistically significant relationship (P<or=.01) between increasing angina and state and trait anxiety.

CONCLUSION

This study identifies the major sources of anxiety described by this sample. In doing so it may facilitate greater understanding of the needs of these patients and assist in the development of specific interventions to help alleviate this problem.

Does ageism affect the management of ischaemic heart disease?

OBJECTIVES

To analyse access by age to exercise testing, coronary angiography, revascularisation (percutaneous transluminal coronary angioplasty/stent insertion and coronary artery bypass graft surgery) and receipt of thrombolysis, where indicated, for hospital patients with diagnosed cardiovascular disease.

METHOD

Retrospective case note analysis, tracking each case backwards and forwards by 12 months from the patient's date of entry to the study. The setting was a district hospital in the eastern part of outer London. The case notes eligible for inclusion were those of elective and emergency in-patients with an in-patient ICD-10 code of ischaemic heart disease, angina pectoris or acute myocardial infarction and a consecutive 20% sample of new cardiac outpatients with these diagnoses.

RESULTS

Analysis of 712 case notes showed that older hospital patients with ischaemic heart disease, and with indications for further investigation, were less likely than younger people to be referred for exercise tolerance tests and cardiac catheterisation and angiography. This was independent of both gender and severity of condition. Older patients did not appear to be discriminated against in relation to receipt of indicated treatments (revascularisation or thrombolysis), although, in the case of revascularisation, older patients were more likely to have been filtered out at the investigation stage (catheterisation and angiography), so selection bias partly explains this finding.

CONCLUSIONS

The current findings from a single hospital are comparable with the results from a broader study of equity of access by age to cardiological interventions in another district hospital in the same region. Although only two hospitals were analysed, the similarity of findings enhances the generalisability of the results presented here. It appears that age per se causes older cardiac hospital patients to be treated differently.

Changes in nutritional status and postoperative outcomes in elderly CABG patients

OBJECTIVES

To systematically examine the pattern of nutritional status over time in older people undergoing elective coronary artery bypass grafting (CABG) and the extent to which nutritional status affects health outcomes postdischarge.

DESIGN

The sample consisted of 91 community-dwelling English-speaking persons > or = 65 (72.27 +/- 4.85) years of age with normal cognitive function and no active cancer. Data collected prospectively at 3 time points (preoperatively, postoperatively on day 5, and 4 to 6 weeks postdischarge) included serum albumin, transferrin, and calculated Body Mass Index (BMI). The Short-Form 36 Health Status Survey Questionnaire was administered 4 to 6 weeks postdischarge as a primary health outcome measure.

RESULTS

Nutritional status changed over time. For albumin and transferrin, the pattern of change corresponded to the phases of surgical stress (P = 0.001). The BMI decreased from preoperative to 4 to 6 weeks postdischarge (P = 0.001), and this decrease explained 13.8% of the variance in physical health 4 to 6 weeks postdischarge (P = 0.008). The change in the BMI corresponds to an average weight loss of 5% from preoperative to postdischarge.

CONCLUSIONS

Older people undergoing CABG who lose significant weight from preoperative to postdischarge are more likely to have lower self-reported physical health.

Does more "appropriateness" explain higher rates of cardiac procedures among patients hospitalized with coronary heart disease?

BACKGROUND

There have been few studies of the extent to which differences in the pool of patients being managed might account for geographic variations in treatment rates.

OBJECTIVE

For two cardiac procedures, cardiac catheterization and revascularization, we evaluate the hypothesis that differences in "the percentage of patients for whom the procedure is appropriate" is a factor explaining variations in use rates among those hospitalized with coronary heart disease (CHD).

RESEARCH DESIGN

Based on hospital utilization patterns in Massachusetts in 1990, we created 70 small geographic areas. Using 1992 Massachusetts Peer Review Organization data, areas were ranked from highest to lowest based on (empirical-Bayes-adjusted) hospitalization rates for each procedure. One thousand seven hundred four cases from 43 hospitals were sampled, roughly half each from high and low use areas. Half had a procedure and half were candidates for the same procedure but did not have it. For each procedure, medical records were reviewed to determine whether the procedure was (or, for those not having it, would have been) appropriate, based on criteria developed using a modified Delphi approach.

RESULTS

Among those having either procedure, appropriateness rates were similar in high and low rate areas (P = 0.59 for catheterization and P = 0.30 for revascularization). However, among candidates for either procedure who did not have it, appropriateness for performing the procedure was greater in high-rate areas (41.4% vs. 32.1%, P = 0.05 for catheterization; 71.2% vs. 57.2%, P = 0.003, for revascularization).

CONCLUSION

Among those hospitalized with CHD, appropriateness rates for two cardiac procedures are higher in areas with higher use rates.

Coronary subclavian steal syndrome: treatment by stenting of the left subclavian artery

A 48-year-old Turkish male presented with worsening angina and a painful left hand eight years after coronary artery bypass surgery. Coronary angiography showed extensive coronary atherosclerosis with patent vein grafts to his diagonal branch and right coronary arteries. There was a severe narrowing lesion in the left subclavian artery before the origin of the left internal mammary artery (LIMA), which appeared patent. Percutaneous subclavian angioplasty and stent implantation to the left subclavian artery stenosis restored normal flow to the left hand and the LIMA with abolition of his ischemic hand symptom and marked improvement of his angina.

Coronary artery bypass and carotid endarterectomy: combined approach

Controversy exists concerning the best management of patients with coronary artery and carotid artery disease. Between June 1994 and July 2000, 88 patients with coronary artery and carotid artery disease underwent combined coronary artery surgery and carotid endarterectomy. Demographics and perioperative variables of these patients were compared with those of 266 patients undergoing isolated coronary artery surgery. Patients in the combined coronary artery bypass grafting and carotid endarterectomy group were elderly patients (p=0.0001) with a higher prevalence of female gender (p=0.0001), left ventricular dysfunction (p=0.006), left main coronary artery disease (p=0.033), triple-vessel coronary artery disease (p=0.002), unstable angina pectoris (p=0.004), and history of prior neurologic events (p=0.0001). Three (3.4%) patients in the combined group and 5 (1.9%) patients in the isolated coronary artery surgery group (p=0.317) developed perioperative myocardial infarction. Two (2.3%) patients in the combined group developed a permanent postoperative neurologic event. Hospital mortality was 5.7% (5 patients) in the combined coronary artery bypass grafting and carotid endarterectomy group and 1.5% (4 patients) in the isolated coronary artery surgery group (p=0.046). Patients with concomitant carotid and coronary artery disease have an advanced arteriosclerosis. Although combined coronary artery bypass grafting and carotid endarterectomy is associated with a higher risk of death and perioperative myocardial infarction than simple coronary artery surgery, this procedure is a preferable approach for these high-risk patients and results in lower neurologic morbidity.

Cardiac risk assessment for noncardiac surgery: current concepts

Strategies for perioperative risk assessment in patients undergoing noncardiac surgery vary among physicians and are aimed to estimate the risk and minimize complications. We propose simplistic guidelines for assessing and modifying risk for patients undergoing a wide variety of procedures.

Relationship of hospital size, case volume, and cost for coronary artery bypass surgery: analysis of 12,774 patients operated on in Massachusetts during fiscal years 1995 and 1996

OBJECTIVE

This study investigates the relationship between the cost of coronary artery bypass graft surgery and both hospital size and case volume.

METHODS

Retrospective administrative and cost data were obtained for all 12,774 patients who underwent isolated coronary bypass surgery at 12 Massachusetts hospitals during 1995 and 1996. Hospitals were stratified by number of operating beds into 3 groups (group I, <250 beds; group II, 250-450 beds; group III, >450 beds). Total (diagnosis-related groups 106 + 107) annual coronary bypass cases per hospital varied from 271 to 913 (mean 532). Univariate and multivariable analyses were used to study the relationship between the direct and total cost and a number of patient (age, sex, acuity class, payer) and hospital (bed capacity, annual case volume per diagnosis-related group, cardiothoracic residency) predictor variables. For each hospital, we also studied the relationship between changes in coronary bypass case volume and the corresponding changes in average cost from 1995 to 1996.

RESULTS

Scatterplots revealed a broad range of mean direct cost of coronary bypass surgery among hospitals with comparable case volumes. When annual cases were analyzed as continuous variables, there was no linear relationship of case volume with direct or total cost of coronary bypass (r = -0.05 to +0.08) for any diagnosis-related group or year. When hospital bed capacity and case volume were grouped into strata and studied by analysis of variance, there was no evidence of an inverse relationship between these variables and cost. In multivariable analysis, patient acuity class and diagnosis-related group were the most important predictors of cost. Beds and case volume met inclusion criteria for most models but added little to the "explanation" of variability R(2), often less than 1%. Finally, substantial interhospital differences were noted in the magnitude and direction (direct vs inverse) of their 1995 to 1996 change in volume versus change in cost.

CONCLUSIONS

Within the range of hospital size and case volume represented in this study, there is no evidence that either variable is related to the cost of performing coronary bypass surgery. Massachusetts hospitals appear to function on different segments of different average cost curves. It is not possible to predict the relative cost of coronary bypass grafting at a given hospital based primarily on volume.

[Angiographic correlates of the high-risk criteria for conventional exercise testing and the Duke treadmill score]

OBJECTIVE

To compare the sensitivity, the specificity, the positive and negative predictive value and the predictive accuracy of the Duke Treadmill Score, the Spanish Society of Cardiology (SEC) and American College of Cardiology/American Heart Association (ACC/AHA) high-risk criteria for exercise testing in the detection of left main disease, three vessel disease and two vessel disease involving the proximal left anterior descending artery.

PATIENTS AND METHOD

A cohort of 199 patients (age 75 years) consecutively admitted to hospital for unstable angina was studied. All patients underwent an exercise stress test and coronariography.

RESULTS

The SEC high-risk Criteria showed a sensitivity of 69.2% and a specificity of 49.0%. The ACC/AHA high-risk Criteria demonstrated a sensitivity of 98.1% and a specificity of 23.8% and the Duke Treadmill Score presented a sensitivity of 30.8% and a specificity of 90.5%. In patients with moderate risk in the Duke Treadmill Score we found a sensitivity of 62.9% and a specificity of 39.8% for the SEC high-risk criteria, while the ACC/AHA high-risk Criteria presented a sensitivity of 100.0% and a specificity of 5.8%.

CONCLUSIONS

The ACC/AHA high-risk Criteria showed a higher sensitivity while the Duke Treadmill Score presented a higher specificity for the detection of left main disease, three vessel disease and two vessel disease involving the proximal left anterior descending artery. The ACC/AHA and SEC high-risk Criteria were found to be very useful in the group of patients with moderate risk in the Duke Treadmill Score.

N1 esophageal carcinoma: the importance of staging and downstaging

OBJECTIVE

To evaluate the effects of clinical staging and downstaging by induction chemoradiation therapy in patients with N1 esophageal carcinoma.

METHODS

Sixty-nine consecutive patients with regional lymph node metastases (cN1) according to clinical staging received induction therapy before surgery. These were compared to 75 patients both clinically and pathologically N1 (cN1/pN1) who underwent surgery without induction therapy and 79 patients clinically and pathologically not N1 (cN0/pN0) who underwent surgery without induction therapy. Analyses focused on survival and the cost and benefit of therapy.

RESULTS

For comparison, the extremes of 5-year survival were 69% for cN0/pN0 patients who underwent surgery alone and 12% for cN1/pN1 patients who underwent surgery alone. Of 69 patients who received induction therapy, 37 were pN0 at resection (downstaged); they had an intermediate survival of 37% at 5 years. Those patients not downstaged with induction therapy had a 12% 5-year survival, similar to patients with cN1/pN1 who underwent surgery alone. After adjusting for the strongest predictors of poor outcome, pN1, and increasing N1 burden, a modest increased risk of death after induction therapy was identified. However, this cost of induction therapy was more than counterbalanced by the benefit of improved survival of downstaging to pN0.

CONCLUSIONS

(1) pN1 is the strongest determinant of poor outcome. (2) cN1 patients who are downstaged by induction chemoradiation therapy to pN0 have an intermediate outcome. (3) cN1 patients who are not downstaged by induction therapy have a poor outcome.

The radial artery versus the saphenous vein graft in contemporary CABG: a case-matched study

BACKGROUND

Although use of the internal thoracic artery has been shown to improve outcomes after coronary artery bypass grafting, the same cannot be said of alternative arterial conduits. To determine the benefit of radial artery (RA) grafting, a case-matched review was undertaken.

METHODS

Between March 1994 and March 1999, 2,847 patients underwent isolated coronary artery bypass grafting with a left internal thoracic artery graft, plus saphenous vein grafts (SVGs). Of these patients, 478 also received an RA graft (RA group). The RA patients were matched at a ratio of 1:2 with patients receiving only SVGs and a left internal thoracic artery graft (SVG group; n = 956) using six prognostic risk factors: age, sex, Canadian Cardiovascular Society class, left ventricular grade, number of diseased vessels, and timing of operation. Target vessels were graded according to quality and graftability and were similar between groups. Outcomes were evaluated by univariate and multivariate analyses.

RESULTS

There was a significantly higher prevalence of diabetes, hypertension, and peripheral vascular disease in the RA group (p < 0.05). Although stay in the intensive care unit was shorter in the RA group (RA, 30 +/- 2 hours, and SVG, 37 +/- 2 hours; p = 0.0002), total hospital stay was similar between groups. The incidence of perioperative myocardial infarction was higher in the SVG group (SVG, 31 of 956 or 3.2%, and RA, 6 of 478 or 1.3%; p = 0.02). Multivariate analysis revealed RA grafting to be protective against early mortality and morbidity (odds ratio = 0.58; 95% confidence interval, 0.37 to 0.90; p = 0.015) and late mortality and morbidity including late reintervention (risk ratio = 0.60; 95% confidence interval, 0.37 to 0.93; p = 0.02). Actuarial freedom from events at 36 months postoperatively was greater in the RA group (RA, 95% +/- 2%, and SVG, 86% +/- 4%; p = 0.01).

CONCLUSIONS

Despite a higher prevalence of preoperative comorbidity, patients in the RA group demonstrated improved outcomes after coronary artery bypass grafting. The RA is a viable and beneficial conduit for this operation.

Waiting for coronary artery bypass surgery: a qualitative analysis

Waiting lists for coronary artery bypass surgery (CABS) are common in many developed countries. Yet, there is limited information available regarding patients' health care needs at this time. This paper reports on a prospective study which aimed to investigate the experience of waiting for CABS from a qualitative perspective. An inductive research approach was used to conduct interviews with 70 randomly selected patients at three intervals over the first year on the waiting list - referral for surgery, again after waiting 6 months (n=49), and finally after waiting for 1 year (n=28). Attrition was mainly caused by surgery having been performed (n=36), although death (n=4) and refusal to participate (n=2) also contributed. Domicilliary interviews were taped and transcribed verbatim. Thematic content analysis identified three central themes in this experience - uncertainty, chest pain and anxiety; with six secondary themes - powerless, dissatisfaction with treatment, anger/frustration, physical incapacity, reduced self-esteem, and altered family and social relationships. The nature and meaning inherent in each theme is described using interview quotations, and a model is proposed which summarizes this data and the relationship between themes. From this analysis, uncertainty, chest pain and anxiety emerge as important indicators of a negative outcome for these patients. This report strongly suggests that patients awaiting bypass surgery require more information regarding the waiting time for such a surgery. Nurses should also offer advice regarding pain management to help improve patients' skills and decrease the fear associated with angina. Nursing intervention and support should also be directed at reducing patients' anxiety levels. This is the first known qualitative study which specifically examines patients' perception of the waiting period prior to bypass surgery. It may therefore provide new evidence on which to base practice for nurses in both hospital and community, and may also stimulate further research in this area.

Multicenter radial artery patency study (RAPS). Study design

The use of an internal thoracic artery rather than a saphenous vein graft for left anterior descending coronary artery bypass is associated with improved long-term outcome. Hence, expanded use of arterial conduits for other coronary targets has been advocated. The radial artery possesses a number of anatomic features that are technically advantageous compared with other arterial conduits. This study will determine the relative patency of the radial artery compared to the saphenous vein for right and circumflex coronary bypass. Patients with graftable multivessel coronary disease and an estimated left ventricular ejection fraction >/= 35% undergoing nonemergent primary isolated coronary bypass surgery are eligible. The right and circumflex vessels must have high-grade lesions (>/= 70% diameter stenosis), with target segments of reasonable quality >/= 1.5 mm in diameter. Patients serve as their own controls. The radial artery is randomly allocated to bypass the right or circumflex territory and a saphenous vein is used for the nonradial site. An internal thoracic artery is used for the left anterior descending coronary artery in all cases. Randomization is stratified by center. The primary study endpoint is graft patency as determined by angiography, 8-12 months postoperatively. The relative patency of the radial artery compared with the saphenous vein will be determined using McNemar's test. A sample size of 464 patients will provide 80% power for a two-tailed test (alpha = 0.05) for a 40% relative reduction in the rate of distal anastomotic occlusion from 12% in the saphenous vein to 7.2% in the radial arteries assuming a 20% within-patient correlation. A single interim analysis will be performed following completion of 232 angiograms. To allow for lack of follow-up angiography in up to 20% of enrolled patients, we plan to randomize a total of 560 patients. It is also our intention to assess the long-term patency (5-10 years) of radial artery relative to saphenous vein grafts in follow-up studies. Three hundred patients were recruited from 12 Canadian, university-affiliated sites from November 1996 until February 1999, of which 128 patients have undergone follow-up angiography. Approximately 80% of those who have been followed for more than 1 year have undergone follow-up angiography. This trial will determine the 8-12 month patency of the radial artery relative to the saphenous vein for non-left anterior descending coronary bypass using a novel study design which helps control for potential bias from individual patient and vessel factors. Positive results would support the use of the radial artery in particular, and multiple arterial grafts in general.

Incidence and risk factors associated with cardiac arrhythmias during rehabilitation after coronary artery bypass surgery

OBJECTIVE

To evaluate the clinical relevance of cardiac arrhythmias during rehabilitation after coronary artery bypass graft (CABG) surgery.

DESIGN

Survey of consecutive patients admitted to an inpatient cardiac rehabilitation center.

SETTING

A rehabilitation center acting as a reference for cardiology clinics lacking this facility. The program was performed in the inpatient setting.

PATIENTS

Two hundred sixty patients undergoing elective CABG surgery for angina.

INTERVENTIONS

Four-week cardiac rehabilitation program. A 24-hour electrocardiographic examination was performed during the first 2 days and, subsequently, on a daily basis.

MAIN OUTCOME MEASURES

Incidence and type of cardiac arrhythmias during rehabilitation; identification of factors associated with an increased risk of cardiac arrhythmias.

RESULTS

Cardiac arrhythmias were recorded in 33.5% of the patients and were more frequent in patients with hypertension (47%), diabetes (42.4%), and hyperlipidemia (36.5%), compared with patients free from these diseases (15.5%) (p < .05). Arrhythmias were also recorded in patients older than 70 years (49%), compared with those younger (29.2%) (p < .01), and in patients who discontinued amiodarone (64.3%) compared with those who did not interrupt the drug (16%) (p < .005). Arrhythmias precluded rehabilitation in 5% of the patients and caused death in one patient.

CONCLUSION

Surveillance for the development of cardiac arrhythmias during cardiac rehabilitation after CABG surgery may allow the early detection and treatment of arrhythmias in a substantial number of patients.

Trends in coronary artery bypass surgery results: a recent, 9-year study

BACKGROUND

The demographics of patients undergoing coronary artery bypass grafting (CABG) have changed over time and may contribute to differing operative mortality and the combination of mortality and morbidity (M + M). In this study, the trends in results are analyzed and causes are suggested.

METHODS

Prospectively collected data concerning 4,839 CABG operations was divided into three time cohorts (1990 to 1992, 1993 to 1995, 1996 to 1998) and analyzed by univariate and multivariate techniques.

RESULTS

Mean age and female gender frequency increased in the later time cohorts (60.7 +/- 9.0 to 63.4 +/- 9.9 years and 16.5% to 21.4%, respectively). The following comorbidities were more prevalent in the later time cohorts: diabetes (26.7% versus 18.6%), renal failure (8.5% versus 2.2%), peripheral vascular disease (20.7% versus 11.0%), previous cerebrovascular accident (6.7% versus 5.0%), urgent procedures (41.5% versus 26.9%), unstable angina (47.8% versus 31.7%), urgent CABG following myocardial infarction (17.1% versus 7.3%), previous percutaneous transluminal coronary angioplasty (8.0% versus 4.5%), ejection fraction less than 35% (20.5% versus 10.4%), (all p < 0.05). Procedurally, increased utilization of the left internal mammary artery, multiple arterial conduits, and warm blood cardioplegia occurred in the later cohorts (91.2%, 22.2%, and 80.4% versus 78.7%, 3.4%, and 38.0%, respectively). The mortality rate was 2.0% and the M + M rate was 15.6% in all 4,839 patients. The mortality and M + M for the three cohorts were 1.6%, 2.0%, and 2.3% and 18.4%, 17.2% and 12.5%, respectively. The risk-adjusted mortality and M + M decreased from 2.4% and 15.9%, respectively, in 1990 to 1992 to 1.8% and 8.4% in 1996 to 1998 (p < 0.001). The difference in adjusted event rates was minimized when the surgical factors were entered into the model.

CONCLUSIONS

Over time, there has been a trend toward operating on older patients with more comorbidities. Though hospital mortality has been stable, risk-adjusted M + M has been in a constant decline. This decline was associated with an increased use of left internal mammary artery grafts, multiple arterial conduits, and warm blood cardioplegia during the later years of the study.

Intensity of antianginal therapy in patients referred for coronary angiography: a comparison of fee-for-service and health maintenance organization therapeutic strategies

BACKGROUND

No formal criteria have been developed to guide medical therapy for angina prior to revascularization, and no comparisons have been made between health maintenance organization (HMO) and fee-for-service (FFS) hospitals with respect to angina treatment.

HYPOTHESIS

Using a literature-based measure of medical intensity, we tested the hypothesis that there is no difference in anginal medical therapeutic intensity between HMO and FFS systems.

METHODS

For each antianginal drug, we developed a model from which an intensity score between 0 and 100 could be calculated. Average and maximal daily doses of drug were fit to a sigmoid curve such that they represented scores of 50 and 99, respectively. Overall intensity scores were obtained by weighted and unweighted averaging of three scores from nitrates, calcium-channel blockers, and beta blockers. This model was applied to 199 patients undergoing angiography at an FFS and an HMO hospital.

RESULTS

HMO patients were taking more classes of antianginal drug (1.9 vs. 1.0, p < 0.001). Overall unweighted (17.7 vs. 11.7, p = 0.02) and weighted (27.3 vs. 16.9, p = 0.003) intensity scores for both HMO and FFS patients were low. HMO intensity scores for the use of beta blockers were greater than FFS scores (19.2 vs. 9.6, p = 0.002). The intensity scores for the use of nitrates and calcium blockers were similar.

CONCLUSIONS

Models for the measurement of anginal medical therapy intensity can provide important information regarding medical therapy prior to revascularization. The overall intensity of medical therapy was low in both health care systems. These findings have important implications for patient management, guideline development, and national healthcare policy.