Changes in patients undergoing coronary artery bypass grafting: 1987-1990. Northern New England Cardiovascular Disease Study Group

Profile of Coronary Artery Bypass Surgery in United Arab Emirates: Dubai Hospital Experience

Although coronary artery bypass surgery has become a common procedure, there were no data available regarding this type of surgery in the United Arab Emirates. Therefore, we undertook this retrospective study of the first 522 consecutive patients undergoing coronary artery bypass graft surgery between October 1992 and July 1997. The mean age was 49.1 years at operation with a 97.1% male predominance. Patients of Asian origin accounted for 75.8%, Arabs 22.4%, and Europeans 1.7%. Chronic stable angina was the most frequent presenting symptom (70.4%) and 62.1% patients had at least one prior myocardial infarction. There was a 44.6% incidence of hypertension and 32.9% of patients were diabetic. Other prominent risk factors were smoking (55.7%), hyperlipidemia (53.9%), and family history of ischemic heart disease (10.7%). Left main coronary artery obstruction was evident in 6.5% of patients. An average of 3.4 grafts per patient were performed using reverse saphenous vein and endarterectomies were needed in 2.2%. The early mortality rate in elective cases was 2.4%. This study suggests that in spite of a high incidence of multiple risk factors, our patients tolerated coronary artery bypass surgery well. Our findings highlight the trend towards more urgent operations and the decreasing age of patients with severe coronary artery disease.

Early outcome of Coronary Artery Bypass Graft Surgery in patients with significant Left Main Stem stenosis at a tertiary cardiac care center

Objective:

Primary objective of this study was to evaluate the impact of significant left main stem (LMS) stenosis on the early outcome of coronary artery bypass graft (CABG) surgery.

Methods:

A Retrospective non-randomized analytical study was conducted in Cardiac surgery department, Chaudhary Pervaiz Elahi Institute of Cardiology (CPEIC) Multan, Pakistan. The data of patients who underwent isolated CABG at our institution from February 2008 to March 2014 were analyzed. Two thousand six hundred two (2602) patients of isolated CABG were divided into 2 groups according to the LMS disease. Group I (n=2088): without significant LMS disease and Group II (n=514): with LMS disease. Data was analyzed using SPSS V16. The groups were compared using Student’s t-test for numeric variables. Chi-square test and Fishers Exact test were used for categorical variables. P-value ≤ 0.05 was considered as significant difference.

Results:

Out of two thousand six hundred two, 2088 patients were in Non.LMS group (Control Group) and five hundred fourteen were in LMS Group (Study Group). Patients with LMS disease were older. In both groups there was no statistically significant difference regarding gender distribution, risk factors of IHD, pre-operative renal function and preoperative CKMB levels. Significant number 50 (9.7%) of patients were unstable in LMS group and they needed urgent surgery (p-value <0.0001). Need and duration for inotropic support and intra-aortic balloon counter-pulsation support were significantly high in LMS group (p-value <0.0001, 0.002, 0.003 respectively). Similarly Mechanical ventilation time and hospital stay were higher in LMS group. Incidence of pulmonary complications and operative mortality were significantly higher in LMS group (p-value 0.005 and 0.001 respectively). Mortality of CABG patients with significant left main coronary stenosis was 13 out of five hundred fourteen (2.5%) as compared to just 17 out of two thousand eighty eight (0.8%) in control group.

Conclusion:

This study showed that significant LMS disease is an independent risk factor for early cardiopulmonary morbidity and mortality after CABG surgery.

Predicting adverse outcomes of cardiac surgery with the application of artificial neural networks

Risk-stratification models based on pre-operative patient and disease characteristics are useful for providing individual patients with an insight into the potential risk of complications and mortality, for aiding the clinical decision for surgery vs non-surgical therapy, and for comparing the quality of care between different surgeons or hospitals. Our study aimed to apply artificial neural networks (ANN) models to predict mortality and morbidity after cardiac surgery, and also to compare the efficacy of this model to that of the logistic regression model and Parsonnet score. The accuracy of the ANN, logistic regression and Parsonnet score in predicting mortality was 83.8%, 87.9% and 78.4%. The accuracy of the ANN, logistic regression and Parsonnet score in predicting major morbidity was 79.0%, 74.3% and 68.6%. The area under the receiver operating characteristic curves (AUC) of the ANN, logistic regression and Parsonnet score in predicting in-hospital mortality were 0.873, 0.852 and 0.829. The AUCs of the ANN, logistic regression and Parsonnet score in predicting major morbidity were 0.852, 0.789 and 0.727. The results showed the ANN models have the best discriminating power in predicting in-hospital mortality and morbidity among these models.

Prediction for Major Adverse Outcomes in Cardiac Surgery: Comparison of Three Prediction Models

BACKGROUND/PURPOSE

Recent advances in medical treatment have altered the profile of patients referred for cardiac surgery. The proportion of high risk patients has increased dramatically. Numerous multifactorial risk scores have been developed to predict outcomes after cardiac surgery. However, these additive risk models were all developed outside of Asia and have never been validated in Taiwan. We applied the Parsonnet score, Tu score and logistic regression to a population in Taiwan who received cardiac surgery to predict the mortality, morbidity and likelihood of prolonged stay in the intensive care unit (ICU).

METHODS

This retrospective study included 622 adult patients who received cardiac surgery during a 2-year period at Taichung Veterans General Hospital. The patients were randomly divided into a reference set (n = 423) and a validation set (n = 199). The Parsonnet score and Tu score were calibrated separately with the reference set to determine mortality, morbidity and likelihood of prolonged ICU stay. We developed a separate logistic regression model for each of the three outcomes by using the reference set. The validation set was used to test these models.

RESULTS

The area under the receiver operating characteristic (ROC) curve (AUC) of the Parsonnet score, Tu score and logistic regression for predicting in-hospital mortality were 0.843, 0.714 and 0.867, respectively. The AUC of the Parsonnet score, Tu score and logistic regression for predicting major morbidity were 0.784, 0.736 and 0.808, respectively. The AUC of the Parsonnet score, Tu score and logistic regression for predicting likelihood of prolonged ICU stay were 0.701, 0.689 and 0.764, respectively.

CONCLUSION

The Parsonnet score performed as well as the logistic regression models in predicting major adverse outcomes. The Parsonnet score appears to be a very suitable model for clinicians to use in risk stratification of cardiac surgery.

Feasibility of percutaneous coronary interventions in early postcoronary artery bypass graft occlusion or stenosis

BACKGROUND

With continuing technical advances in percutaneous coronary interventions (PCI) for coronary artery disease (CAD), patients undergoing coronary artery bypass surgery (CABG) often have complex coronary anatomy that is not ideal for PCI. Because of the complex anatomy, these patients have a higher risk of early graft occlusion. The feasibility of PCI in the treatment of early graft occlusion is not well established.

METHODS

A retrospective chart review was performed of patients presenting with recurrent ischemia within three months post-CABG and at one-year follow-up.

RESULTS

Forty-six patients with 156 grafts were identified. Three presented with STEMI, 21 with NSTEMI, 21 with unstable angina, and one with congestive heart failure. Sixty-three grafts were occluded or stenosed (>70%). Twenty-seven grafts (43%) in 17 patients were not amenable to PCI. The other 34 grafts (54%) in 23 patients underwent successful PCI. PCI was performed upon native vessels and occluded grafts with equal frequency. Six patients had patent grafts. At one-year follow-up, six of 23 patients in the PCI group were readmitted with ischemia; five vessels (14%) in four patients had restenosed. There were no deaths. In the group with no PCI, 11 of 23 patients were readmitted with ischemia with one death.

CONCLUSION

PCI for early post-CABG occlusion was safely performed in slightly more than half of target vessels. PCI was performed upon native vessels and occluded grafts with equal frequency. After initial PCI success, the clinical target vessel restenosis rate was 14% at one-year follow-up.

Fast-track failure after cardiac surgery: Development of a prediction model*

OBJECTIVE

Risk factors for unsuccessful fast-tracking of cardiac surgery patients have not been collectively defined in the literature. The aim of this study was to determine risk factors for fast-track failure and incorporate them into a predictive fast-track failure score.

DESIGN

Prospective observational study.

SETTING

Cardiothoracic Department of St Mary's Hospital, London.

PATIENTS

Data were collected from April 2003 to April 2005 including 1,084 patients undergoing heart surgery who were admitted into the fast-track unit.

INTERVENTIONS

Multifactorial logistic regression was used to develop a propensity score for estimating the likelihood of fast-track failure.

MEASUREMENTS AND MAIN RESULTS

One hundred and sixty-nine patients failed fast-track management (15.6%). Independent predictors for fast-track failure were impaired left ventricular function with or without recent acute coronary syndrome (odds ratios 2.89 and 1.65 respectively), re-do operation (one, two, or more vs. none, odds ratio 1.75, 7.98), extracardiac arteriopathy (odds ratio 2.63), preoperative intra-aortic balloon pump (odds ratio 3.09), raised serum creatinine in micromol/L (120-150, >150 vs. <120, odds ratio 1.57, 11.24), and nonelective (odds ratio 3.43) and complex surgery (odds ratio 2.70). Model validation showed very good discrimination (area under the curve = 0.815) and calibration (ĉ statistic = 8.527, p = .129).

CONCLUSIONS

The fast-track failure score incorporates several preoperative factors and has been successfully internally validated; after undergoing external validation and possible recalibration it may be used as a tool to facilitate planning and flow of cardiac surgery patients, based on the predicted probability of failure. Application of this score may limit fast-track failure rates and help to reduce morbidity and cost.

Trends in coronary artery revascularisation procedures in Western Australia, 1980-2001

OBJECTIVES

To describe trends in the use of coronary artery revascularisation procedures (CARPs) and to determine whether or when CARP rates will stabilise.

SETTING

State of Western Australia.

PATIENTS

All patients treated by coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI) between 1980 and 2001.

DESIGN

Descriptive study.

MAIN OUTCOME MEASURES

Age standardised rates of first and total CARPs, CABGs, and PCIs.

RESULTS

Overall rates for both total and first CARPs among men and women rose steeply from 1980 to 1993, when they abruptly stabilised or actually started to decline. Rates in age groups under 65 years tended to rise earlier in the period and remained relatively flat, while rates for people over the age of 75 years started to rise later and were still increasing at the end of the study.

CONCLUSIONS

Despite continuing increases in capacity to perform both CABG and PCI in Western Australia and evidence of continuing increases in the use of CARPs in the elderly population, rates appear to have stabilised for the first time since they were introduced.

Impact of sodium-hydrogen exchange inhibition by cariporide on death or myocardial infarction in high-risk CABG surgery patients: results of the CABG surgery cohort of the GUARDIAN study

OBJECTIVES

To evaluate the effects of cariporide on all-cause mortality or myocardial infarction at 36 days in patients at risk of myocardial necrosis after coronary artery bypass graft surgery.

METHODS

In the coronary artery bypass graft cohort of the GUARD During Ischemia Against Necrosis trial, patients > or =18 years who required urgent coronary artery bypass graft, repeat coronary artery bypass graft, or had a history of unstable angina and > or =2 risk factors (age >65 years, female gender, diabetes mellitus, ejection fraction <35%, or left main or 3-vessel disease) were randomized to placebo (n = 743) or cariporide 20 mg (n = 736), 80 mg (n = 705), or 120 mg (n = 734). A 1-hour intravenous infusion was initiated shortly before surgery and administered every 8 hours for 2 to 7 days. Patients were followed up for 6 months. A nonparametric covariance analysis was used to calculate the primary efficacy endpoint.

RESULTS

Baseline characteristics were similar between treatment groups. The cariporide 20- and 80-mg groups had event rates similar to placebo. The endpoint of all-cause mortality or myocardial infarction at day 36 was significant with cariporide 120 mg versus placebo (event rate 12.2% vs 16.2%; P =.027). The risk reduction was evident on postoperative day 1 (3.3% vs 6.5%; P =.005) and was maintained at 6 months (event rate 15.0% vs 18.6%; P =.033). Cariporide was well tolerated, and most adverse events were mild and transient in this high-risk population.

CONCLUSIONS

Clinical benefit with cariporide 120 mg was observed early after treatment initiation and continued for 6 months postsurgery, suggesting that sodium-hydrogen exchange inhibition with cariporide is cardioprotective in patients undergoing high-risk coronary artery bypass graft surgery.

Rehabilitation of postcardiac surgery stroke patients. Progress, outcomes, and comparisons with other stroke patients

OBJECTIVE

To examine the demographics, progress, and functional outcomes of all postcardiac surgery stroke patients admitted to the rehabilitation unit of an acute, tertiary general hospital over a 5-yr period and to compare this cohort with an age-matched control group of other stroke patients admitted during the same period.

DESIGN

A retrospective chart review of 47 postcardiac surgery stroke and a matched control group of other stroke patients admitted to the rehabilitation unit.

RESULTS

The mean age of the postcardiac surgery stroke patients was 70.80 +/- 8.37 yr, with 60% of patients being male. Their average length of stay on the rehabilitation unit was 15.64 +/- 11.96 days. Mean admit FIM total score was 65.64 +/- 16.33, with a discharge FIM total score of 86.77 +/- 18.93. Mean admit FIM motor score was 41.47 +/- 9.45, with a discharge FIM motor of 60.74 +/- 13.20. The other stroke group had significantly greater admit FIM total (P = 0.03), admit motor (P = 0.001), and discharge motor (P = 0.025) scores. FIM efficiency and motor and cognitive gains were comparable between the two groups. Length of stay on the rehabilitation unit was approximately 2 days less (P = 0.224) for the other stroke cohort. Ultimately, 39 (83%) of the postcardiac surgery stroke patients were discharged to the community compared with 45 (96%) of the other stroke patients (P = 0.19).

CONCLUSIONS

The majority of postcardiac surgery stroke patients successfully completed a comprehensive inpatient rehabilitation program. They had lower admit FIM total scores and admit and discharge FIM motor scores than the other stroke group and were almost as likely to ultimately return to the community.

Preoperative pulmonary assessment of the older adult

Postoperative pulmonary complications in the elderly are common and are a significant source of morbidity, mortality, and prolonged length of stay. Risk factors differ from the well-known risk factors for cardiac complications and can be divided into patient- and procedure-related factors. Patient-related factors include COPD, recent cigarette use, poor general health status as defined by Goldman or ASA class, dependent functional status, and laboratory parameters including abnormal chest radiograph, renal insufficiency, and low serum albumin. Age is a minor risk factor when adjusted for comorbidities and confers approximately a two-fold increase in risk. Elderly patients who are otherwise acceptable surgical candidates should not be denied surgery based solely on age and concern for postoperative pulmonary complications. The surgical site is the single most important predictor of pulmonary complications. High-risk surgeries include thoracic, upper abdominal, aortic, neurosurgery, and peripheral vascular. Other procedure-related risk factors include surgery lasting longer than 3 hours, the use of general anesthesia, pancuronium use, and emergency surgery. Clinicians should not recommend routine preoperative spirometry before high-risk surgery because it is no more accurate in predicting risk than clinical evaluation. Patients who might benefit from preoperative spirometry include those who have unexplained dyspnea or exercise intolerance and those who have COPD or asthma in whom uncertainty exists as to the status of airflow obstruction when compared with baseline. After identifying patients at risk for postoperative pulmonary complications, clinicians can recommend strategies to reduce risk throughout the operative period. In addition to minimizing or avoiding the above risk factors, optimization of COPD or asthma, deep breathing exercises, incentive spirometry, and epidural local anesthetics reduce the risk of postoperative pulmonary complications in elderly surgical patients.

A risk model derived from the National Registry of Myocardial Infarction 2 database for predicting mortality after coronary artery bypass grafting during acute myocardial infarction

The mortality risk associated with coronary artery bypass grafting (CABG) after acute myocardial infarction (AMI) remains controversial. Although elective CABG is quite safe, the effects of recent myocardial infarction, gender, and other clinical factors on perioperative mortality rates are not completely understood. The objective of this study was to determine in-hospital mortality rates for patients with AMI receiving CABG and to generate a model to predict the risk for any individual patient with specific risk factors. Using the National Registry of Myocardial Infarction 2 database, we identified 71,774 subjects (21,270 women) with AMI who underwent CABG; we excluded those subjects who received immediate surgery as reperfusion therapy. Multivariate logistic regression was used to quantify the independent effects of age, recent myocardial infarction, gender, and other covariates on mortality. A risk score was then generated from the regression model to quantify the mortality risk. The results of logistic regression modeling determined that age was an independent predictor of in-hospital death (adjusted odds ratio [OR] 3.05, 95% confidence interval [CI] 2.76 to 3.37 for age >75), as were previous CABG (OR 2.84, 95% CI 2.55 to 3.16), heart failure on presentation (OR 1.73, 95% CI 1.57 to 1.91 for Killip class II), and female gender (OR 1.58, 95% CI 1.45 to 1.71). The mortality risk score showed that 55% of patients had risk scores of 2 to 5 and mortality rates of 4% to 13%. This moderate risk group experienced 76% of the total predicted mortality. Thus, in-hospital CABG mortality rates after AMI are high compared with elective surgery. Using the described risk score, clinicians can quantify the impact of patient risk factors in making decisions about referral for and timing of CABG.

Thyroid hormone and cardiac surgery

Thyroid hormone has important effects on the heart and peripheral vascular system. The relationship between thyroid disease states and cardiovascular hemodynamics is well recognized. Diverse clinical situations are associated with low serum triiodothyronine (T3) levels including a number of cardiovascular illnesses. In particular, cardiopulmonary bypass and open heart operations result in a low T3 state and are often complicated by significant cardiovascular dysfunction similar to that observed in clinical hypothyroidism. Multiple lines of evidence have suggested that T3 can act acutely as a positive inotrope and vasodilator agent. This recognition has prompted a number of investigators to study the effects of T3 administration to patients in the perioperative period. This paper reviews the experimental background that supported such clinical trials as well as outlines the results that have been documented in both adult and pediatric patients undergoing cardiac surgery. Low serum T3 levels resulting from cardiopulmonary bypass can be safely reversed with pharmacologic T3 supplementation. Data have suggested that T3 repletion may improve postoperative hemodynamic performance and lower the incidence of arrythmias. However, beneficial effects on major clinical outcome variables have not yet been conclusively demonstrated, and require future large-scale clinical trials.

In-hospital outcomes of off-pump versus on-pump coronary artery bypass procedures: a multicenter experience

BACKGROUND

Concern about the possible adverse effects of the cardiopulmonary bypass (CPB) pump and advances in retractors and operative techniques to access all coronary segments have resulted in increased interest in off-pump coronary artery bypass (OPCAB) procedures. Four of the Northern New England Cardiovascular Disease Study Group centers initiated OPCAB programs in 1998. We compared the preoperative risk profiles and in-hospital outcomes of patients done off-pump with those done by conventional coronary artery bypass (CCAB) with CPB.

METHODS

Between 1998 and 2000, 1,741 OPCAB and 6,126 CCAB procedures were performed at these four medical centers. Minimally invasive direct coronary artery bypass grafting procedures were excluded. Data were available for patient and disease risk factors, extent of coronary disease and adverse in-hospital outcomes.

RESULTS

The OPCAB and CCAB groups were somewhat different in their preoperative patient and disease characteristics. The OPCAB patients were more likely to be female and to have peripheral vascular disease. The CCAB patients were more likely to have an ejection fraction less than 0.40 and be urgent or emergent at operation. However, overall predicted risk of in-hospital mortality, based on preoperative factors, was similar in the OPCAB and CCAB groups; the mean predicted risk was 2.6% (p = 0.567). Crude rates of mortality (2.54% OPCAB versus 2.57%, CCAB), intraoperative or postoperative stroke (1.33% versus 1.82%), mediastinitis (1.10% versus 1.37%), and return to the operating room for bleeding (3.46% versus 2.93%) did not differ significantly. The OPCAB patients did have a statistically significant reduction in the need for intraoperative or postoperative intraaortic balloon pump support (2.31% versus 3.41%; p = 0.023) and in the incidence of postoperative atrial fibrillation (21.21% versus 26.31%; p < 0.001). Adjustment for preoperative risk factors and extent of coronary disease did not substantially change the crude results. Median postoperative length of stay was significantly shorter (5 days versus 6 days, p < 0.001) for OPCAB patients than for CCAB patients.

CONCLUSIONS

This multicenter study showed that patients having OPCAB are not exposed to a greater risk of short-term adverse outcomes. These data also provided evidence that patients having OPCAB have significantly lower need for intraoperative or postoperative intraaortic balloon pump, lower rates of postoperative atrial fibrillation, and a shorter length of stay.

Improved in-hospital mortality in women undergoing coronary artery bypass grafting. Northern New England Cardiovascular Disease Study Group

BACKGROUND

Few studies have examined the changes in in-hospital mortality for women over time. We describe the changing case mix and mortality for women undergoing coronary artery bypass grafting (CABG) from 1987 to 1997 in northern New England.

METHODS

Data were collected on 8,029 women and 21,139 men undergoing isolated CABG. The study consisted of three time periods (1987 to 1989, 1990 to 1992, and 1993 to 1997) to account for regional efforts to improve quality of care that occurred during 1990 to 1992.

RESULTS

Compared with 1987 to 1989, women undergoing CABG in 1993 to 1997 were older, had poorer ventricular function, and more often required urgent or emergency operations. The crude and adjusted mortality rates for both women and men decreased significantly over time. The absolute magnitude of the change in adjusted rates was greater for women (3.1%) than for men (1.5%). Although women represented only 28% of the study population, the decrease in their mortality accounted for 44% of the total decrease in adjusted mortality during the study period.

CONCLUSIONS

Over the last decade there has been a marked decrease in CABG mortality for women, despite a worsening case mix.

Spectrum of surgical risk for left main coronary stenoses: benchmark for potentially competing percutaneous therapies

Coronary artery bypass grafting is the preferred therapy for left main trunk coronary stenoses because of a demonstrated survival advantage compared with medical therapy. Recently, however, advocates of percutaneous intervention have suggested that stenting or atherectomy may provide acceptable results for these patients. To determine the spectrum of surgical outcome among patients with left main trunk coronary stenoses, we analyzed 14 potential covariates of in-hospital and 3-year mortality for a consecutive series of patients without prior coronary artery bypass grafting treated at our institution from January 1990 to December 1995. In-hospital mortality (2.3%) for 1585 consecutively treated patients correlated independently with renal dysfunction, age, and class III to IV heart failure. A model was constructed that allowed prediction of outcome (c-statistic = 0.77, p < 0.0001), and only the 9% of patients at highest risk were found to be at risk for death >5%. Mortality at 3 years (15.6%+/-2.2%) in a previously specified subgroup (n = 285) correlated independently with baseline age, renal dysfunction, and chronic pulmonary disease. A model was constructed that allowed prediction of outcome for the validation sample (four risk groups with 3-year mortality rates of 4.5%+/-2.5%, 6.5%+/-2.8%, 20.0%+/-4.2%, and 39.8%+/-8.5%; p < 0.0001. These data provide a contemporary benchmark of clinical outcome against which possible competing therapies may be compared.

Increased risk and decreased morbidity of coronary artery bypass grafting between 1986 and 1994

BACKGROUND

The collective impact of advances in medical, surgical, and anesthetic care on the characteristics and outcomes of patients who undergo coronary artery bypass grafting was assessed.

METHODS

We compared the demographic and clinical characteristics, preoperative risk factors, morbidity, and mortality of two groups of patients who underwent coronary artery bypass grafting in isolation or in combination with other procedures between July 1, 1986, and June 30,1988 (group 1, n = 5,051), and between January 1, 1993, and March 31, 1994 (group 2, n = 2,793). The patients were stratified according to their preoperative risk level. Outcome measures consisted of changes in preoperative risk categories; hospital mortality rates; overall and risk-adjusted major cardiac, neurologic, pulmonary, renal, and septic morbidity rates; and intensive care unit length of stay.

RESULTS

Changes in the distribution of risk categories, from a median of 2 to 4 on a 9-point scale (p < 0.001), indicated that patients in group 2 were at significantly higher risk than those in group 1. The risk-adjusted mortality rate did not change (2.8% to 2.9%; p = 0.15), but the risk-adjusted morbidity rate decreased significantly (14.5% to 8.8%; p < 0.001).

CONCLUSIONS

At our institution, patients who undergo coronary artery bypass grafting are now at greater preoperative risk at the time of hospital admission. However, their morbidity rate is significantly lower and their mortality rate is unchanged, results that we attribute to the collective impact of changes in our medical and surgical procedures.

Rehabilitation of the post-cardiac surgery stroke patient: analysis of cognitive and functional assessment

OBJECTIVE

Determine whether, as expected, patients sustaining post-cardiac surgery stroke (PCS) (n = 19) differ from other stroke (OS) patients (n = 216).

DESIGN

A total of 235 stroke patients were surveyed. Therapist ratings of Functional Independence Measure (FIM) on admission to and discharge from a rehabilitation unit were compared. Cooperation with formal neuropsychologic evaluation was assessed.

SETTING

The rehabilitation unit of a tertiary care hospital.

PARTICIPANTS

Medical records for consecutive stroke patients were reviewed (January 1994 to December 1995). Groups did not differ in age, gender, or admission FIM.

INTERVENTIONS

Standardized neuropsychologic evaluation of seven cognitive domains was attempted for each patient referred to the neuropsychology service. All of the patients received FIM ratings on admission to and discharge from the rehabilitation unit.

OUTCOME MEASURES

Gain in FIM per week of rehabilitation unit stay (FIM efficiency) and discharge destination.

RESULTS

Contrary to expectations, PCS patients did not differ significantly from OS patients in FIM efficiency or discharge destination. However, PCS patients were significantly less able to cooperate with formal neuropsychologic testing, possibly secondary to their physical condition, higher-level cognitive deficits, or both.

CONCLUSION

Although PCS patients may sustain medical and cognitive deficits that interfere with exhaustive neuropsychologic evaluation, these deficits do not significantly interfere with functional progress in rehabilitation and should not make PCS patients ineligible for rehabilitation services.

Functional outcomes of patients on a rehabilitation unit after open heart surgery

BACKGROUND

Compared with predecessors, the modern-day patient who undergoes cardiac surgery is sicker, is older, has more diffuse disease, has poorer ventricular function, and is more likely to be a repeat surgery. Patients hospitalized after open heart surgery in the 1990s, therefore, may require increasingly comprehensive rehabilitation services before returning to the community; however, information documenting functional progress during, and outcome after, a hospital-based rehabilitation program is scarce.

METHODS

During a 14-month period, a consecutive sample of 44 patients who underwent cardiac surgery and were admitted to a rehabilitation unit in a tertiary acute hospital was studied. Thirty-one patients had coronary artery bypass graft, six had valvular surgery, and seven had both. Each patient's functional status on admission and discharge from the rehabilitation unit was assessed using the Functional Independence Measure. Other data studied included patient age and sex, premorbid medical problems, type of cardiac surgery, length of stay, and occurrence of medical complications in the acute and rehabilitation units.

RESULTS

The mean Functional Independence Measure scores at rehabilitation unit admission and discharge were 76.1 +/- 17.1 and 96.7 +/- 19.4, respectively, and this difference was significant (P < 0.0001). The most significant correlates (alpha = 0.05) of the discharge Functional Independence Measure were admission Functional Independence Measure (P < 0.00001) and length of stay in the acute care unit (P = 0.0072). Age and presence of medical complications were not significant.

CONCLUSION

Patients who undergo open heart surgery, many of whom have medical comorbidity, are able to demonstrate substantial functional improvement on an inpatient rehabilitation program before hospital discharge.

North American experience with the Perma-Flow prosthetic coronary graft

BACKGROUND

The Perma-Flow prosthetic coronary graft is a 5-mm polytetrafluoroethylene tube into which is incorporated a Venturi flow restrictor. An aorto-superior vena caval fistula is created and coronary anastomoses are constructed proximal to the resistor in side-to-side fashion, where arterial pressure is maintained. From November 1992 through December 1995, eight investigational centers in North America have implanted this graft in 40 patients with inadequate autologous alternatives.

METHODS

Patients were selected for inclusion in this study if coronary artery bypass grafting was required and adequate autologous conduit to complete revascularization was not available. Operative data were completed by the implantating surgeon and referred to a central center, the Minneapolis Heart Institute, for correlation. Follow-up was conducted by data coordinators at each institution, and follow-up data were obtained directly from these coordinators for inclusion in the study.

RESULTS

Patient age ranged from 53 to 82 years, and 15 patients were undergoing reoperations (38%). On each Perma-Flow graft one to four coronary side-to-side anastomoses were constructed. In addition, left internal mammary artery (n = 26), greater saphenous vein (8), right internal mammary artery (4), and gastroepiploic artery (4) were used to complete revascularization. Aortic (2) or mitral valve replacement (1) was also carried out. There were seven operative deaths (18%) and two late deaths (4 and 6 months). After 1 to 37 months (mean, 13 +/- 9 months) of follow-up, 29 of 31 surviving patients are asymptomatic. Echocardiographic heart size has not increased from the postoperative value, indicating limited volume load has not affected heart size. Protocol catheterization (n = 32) in 28 patients 1 week to 1 year postoperatively revealed 7 of 73 studied coronary anastomoses (9.5%) and two distal extensions and resistors were occluded (7%). In 1 patient during sternal debridement at 1 year, no flow was found in the graft.

CONCLUSIONS

The Perma-Flow graft is a useful adjunct to complete revascularization in patients with deficient autologous conduit.

Intermittent aortic cross-clamping and cold crystalloid cardioplegia for low-risk coronary patients

BACKGROUND

Blood cardioplegic strategies have been shown to increase myocardial oxygen uptake, replenish depleted energy stores, and improve myocardial function and survival in the high-risk subset of patients. However, the superiority of these techniques over intermittent aortic cross-clamping and crystalloid cardioplegia in low-risk patients is still controversial.

METHODS

This study consisted of two parts. In the first part, we assessed the results of a recent cohort of 399 consecutive low-risk patients undergoing their first coronary artery bypass grafting between 1993 and 1995 using cold crystalloid cardioplegia (n = 128) and intermittent aortic cross-clamping (n = 271). In the second part of the study, 40 consecutive low-risk patients undergoing elective first time coronary artery bypass grafting were randomly divided into two equal groups. One group received cold crystalloid cardioplegia and the other group had myocardial management with intermittent aortic cross-clamping. The two groups were compared with respect to hemodynamic, biochemical and ultrastructural changes.

RESULTS

The overall mortality rate, the perioperative myocardial in the need for intraaortic balloon pumps, and the need for inotropic agents were 0.25%, 1.5%, 1%, and 5.8%, respectively. No significant differences were observed between the groups with respect to these clinically defined end points.

CONCLUSIONS

Both intermittent aortic cross-clamping and cold crystalloid cardioplegia techniques may be used safely in low-risk patients undergoing first-time coronary artery bypass grafting.

Enrollment in the Health Alliance Plan HMO is not an independent risk factor for coronary artery bypass graft surgery

BACKGROUND

Henry Ford Hospital is the sole provider of cardiac surgical services for the Health Alliance Plan, a health maintenance organization (HMO) that presently serves 450,000 enrollees.

METHODS AND RESULTS

To determine the effect of managed care referral patterns on the outcome of coronary artery bypass graft (CABG) surgery, we retrospectively reviewed two concurrent groups of patients, 569 HMO patients and 225 patients with free-for-service (FFS) insurance, who had undergone isolated primary CABG surgery between January 1, 1990 and January 31, 1994. The 605 patients with Medicare operated on during the same time frame were excluded to obviate age bias. Age, sex, use of cardiac medications, history of prior percutaneous transluminal coronary angioplasty or thrombolytic therapy, history of recent and remote myocardial infarction, extent of coronary disease, presence of preexisting comorbid conditions, and incidence of unstable clinical syndromes and left ventricular dysfunction (ejection fraction < 40%) were comparable for both groups. In hospital mortality (HMO group, 1.9%; FFS group, 2.2%), mean ICU stay (HMO, 2.6 +/- 0.3 days; FFS, 2.3 +/- 0.3 days), and total hospital length of stay (HMO, 9.8 +/- 0.8 days; FFS, 8.6 +/- 0.6 days) were likewise similar.

CONCLUSIONS

These data refute the notion that the gate-keeper mentality often associated with managed-care health insurance vehicles results in delayed referral of patients with coronary artery disease and results in suboptimal outcome.

A regional collaborative effort for CQI in cardiovascular disease. Northern New England Cardiovascular Study Group

BACKGROUND

The Northern New England Cardiovascular Disease Study Group has met at least three times a year since 1987 to improve the care of patients with cardiovascular disease. ADVANTAGES OF GROUP EFFORT: The group's collaborative nature has allowed members to have explicit discussions about medical decision making and practice and to benchmark with one another. By collaborating, members have been able to accumulate a large enough experience to examine the fine structure of adverse events, learn from them, and institute meaningful changes. IMPROVEMENT STRATEGIES: Focusing on coronary artery bypass grafting (CABG) procedures, the group has used three improvement strategies: (1) Outcomes are monitored across institutions. All members receive reports with information on their experience, their organization's experience, and the regional experience. (2) All members received training in quality improvement tools and techniques. (3) Members conduct comparative process analysis and benchmarking efforts to learn best practices for CABG surgery.

RESULTS

The average in-hospital mortality associated with CABG surgery in the region has decreased. The group determined that low output failure is the most common cause of post-CABG death across all hospitals, while other causes of death (for example, stroke, bleeding, arrhythmias) have more uneven distributions across hospitals. Individual hospitals have investigated their more unique causes of death; the group as a whole has undertaken a detailed study of more than 400 deaths to determine why patients die of low output failure and what can be done about it.

KEYS TO SUCCESS

Factors contributing to the group's success include the fact that a regionally recognized clinician spearheaded the effort, and a physician "carries the banner" at each institution; data, which are kept confidential, are analyzed and returned in a timely fashion so group members can examine their current, not just their past, practice; and there is an organized forum for data discussion.

Flow characteristics of aortic cannulae

Atheroembolism from the ascending aorta is an emerging cause of noncardiac complications after open heart surgery. We designed a new arterial cannula specifically to reduce the exit force and velocity of blood flow, thereby reducing the "sandblasting" effect of the exiting blood jet. The cannula has a closed tip and an internal cone that diffuses blood flow such that it enters the aorta via multiple side holes. Fluid dynamics of the cannula were tested against five frequently used cannulae: Sarns High-Flow (3M Sarns High-Flow, Ann Arbor, MI, USA), DLP 83024 (DLP Inc., Grand Rapids, MI, USA), RMI ARS 024C (Research Medical Inc. of Research Industries Corp., Midvale, UT, USA), Bard 1966 (C.R. Bard Inc., Haverhill, MA, USA), and Argyle THI (Sherwood Medical Co. Sub American Home Products Corp., St. Louis, MO, USA). All cannulae had an 8.0-mm external diameter. The new cannula demonstrated a similar pressure drop and internal tip diameter as the others. The exit force (newtons) of the Soft Flow cannula was significantly less than the Sarns High-Flow (p < 0.05), DLP (p < 0.001), RMI (p < 0.01), Bard (p < 0.001), and the Argyle (p < 0.001) cannulae. Peak velocity (cm/s) of the Soft Flow cannula was significantly less than the DLP (p < 0.01), RMI (p < 0.01), Bard (p < 0.01), and Argyle (p < 0.001). The cannulae all had similar hemolysis rates. The new arterial cannula produced the lowest exit force and flow velocity with no increase in hemolysis and may help to decrease the incidence of atheroemboli and its sequelae.

Operation for unstable angina pectoris: factors influencing adverse in-hospital outcome

Coronary artery bypass grafting for the treatment of unstable angina is still associated with increased operative risk and postoperative morbidity. The impact of the extended use of arterial grafts on early results is incompletely defined. In a 7-year period (1986 to 1993), 474 patients (average age, 65 years; range, 34 to 85 years) underwent coronary artery bypass grafting for the treatment of unstable angina. Sixty-eight patients were operated on emergently and 406 urgently. They received an average of 3.0 distal anastomoses (range, 1 to 6). Seventy-nine patients had exclusively venous grafts, 316 had one internal thoracic artery graft, 79 had bilateral internal thoracic artery grafts, and 20 had inferior epigastric artery grafts. Sequential internal thoracic artery grafting was performed in 70 patients. Redo operations were performed in 26 patients. Thirty-four patients (7.2%) experienced a new myocardial infarction. Eighty-nine patients (18.8%) had an intraaortic balloon pump inserted preoperatively, intraoperatively, or postoperatively. Eight patients (1.7%) died intraoperatively and 24 patients (5.1%) died postoperatively. Seventy-seven patients (16.2%) had an adverse outcome, as shown by the need for an intraaortic balloon pump (intraoperatively or postoperatively) or hospital death, or by both. Forty variables were examined by multivariate analysis for their influence on the occurrence of an adverse outcome. Aortic cross-clamp time (p = 0.0004), transfer from the intensive care unit (p = 0.0023), female sex (p = 0.0023), operation performed in early years (p = 0.0041), left ventricular aneurysm (p = 0.0068), the number of diseased coronary vessels (p = 0.0312), and reoperation (p = 0.0318) were all found to be significant independent predictors of increased risk.(ABSTRACT TRUNCATED AT 250 WORDS)

Criteria by which to evaluate risk-adjusted outcomes programs in cardiac surgery

Risk adjustment models for hospitalized patients are most advanced for the assessment of the clinical outcome of cardiac procedures, and for coronary artery bypass grafting in particular. The goal of being able to use outcomes as a credible indicator of quality of care has stimulated the development of several programs that use reliable, valid patient data collected during the surgical episode to adjust outcomes for the severity of illness. Several criteria that are useful in the assessment of risk adjustment methods for outcome and quality-of-care investigations are discussed in detail and five of these programs are compared. The programs have more similarities than differences and identify many of the same patient characteristics predictive of a higher likelihood of mortality in the period immediately after operation. Whether persistent differences in mortality after risk adjustment across institutions or individual surgeons, or both, may ultimately be attributed to the process and structure of care needs further study and investigation. Similar methods should be applied to other outcomes of importance to patients, their families, and their physicians, such as surgically related morbidity, functional status, quality of life, costs, and patient-reported perceptions of the nontechnical aspects of their care.