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T Bruce Ferguson

Publications and source records attributed to T Bruce Ferguson.

At least 37 records · Page 2Linked to original sources
PubMed2005

The evaluation of treatment when center-specific selection criteria vary with respect to patient risk.

Many standards of medical care are based on the demonstrated effects of various treatment strategies or processes. Unlike pharmacological treatments, these strategies or processes are not necessarily subjected to rigorous clinical trials and their benefit is frequently assessed from observational data. For evaluating the influence of such medical processes on patient outcomes, not only is risk adjustment an issue, but also the "center effect" represents an important, often overlooked consideration. Both the quality of care and the tendency to use certain treatments or processes vary from one center to another. The induced similarity in outcomes within center, as well as the potential for confounding by center, needs to be addressed within the context of risk adjustment. In addition, center-specific selection criteria for a treatment strategy can vary with respect to patient risk. Because of these considerations, it is important to adequately separate the within-center effects of the treatment or strategy from the across-center effects, which relate more to center performance. The primary objective of this article is to explore and extend current methods of dealing with center confounding for dichotomous outcomes, primarily for the situation where selection on the basis of patient risk can vary from center to center. A simulation study compares results from several different analytic methods and provides evidence for the importance of considering confounding due to both risk and center when evaluating the effectiveness of a process. An example that examines the effect of early extubation after bypass surgery is also presented.

Computer Simulation↗
PubMed2005

Intraoperative interventions: American College of Chest Physicians guidelines for the prevention and management of postoperative atrial fibrillation after cardiac surgery.

A comprehensive evidence review was conducted of the medical literature regarding the relationship between intraoperative interventions and the incidence of postoperative atrial arrhythmias, including, most commonly, atrial fibrillation (AF). Fifteen randomized, controlled studies and one large-scale concurrent cohort study were identified that reported on the following issues: systemic temperature during surgery (one report); "beating heart" surgery vs conventional bypass surgery (three reports); type of myocardial protection (five reports); the use of adjunctive posterior pericardiotomy (one report); the use of thoracic epidural anesthesia (TEA) [two reports]; the use of glucose-insulin-potassium (GIK) solutions (two reports); and the use of heparin-coated circuits for cardiopulmonary bypass (CPB) [two reports]. Based on a systematic review of the reported data and an analysis of the quality of the reported data, we recommend the following: (1) that mild hypothermia, rather than moderate hypothermia, may be effective in reducing the frequency of postoperative AF; (2) the use of posterior pericardiotomy may be a useful adjunct to reduce the frequency of postoperative AF; and (3) the use of heparin-coated CPB circuits is associated with less postoperative AF. Because of conflicting or inadequate data, we cannot conclude that the frequency of postoperative AF is affected by (1) the use of beating-heart techniques, (2) the type of myocardial protection strategy used, (3) the use of TEA, or (4) the use of GIK solutions perioperatively.

Anesthesia, Epidural↗
PubMed2004

Should coronary artery bypass graft surgery patients with mild or moderate aortic stenosis undergo concomitant aortic valve replacement? A decision analysis approach to the surgical dilemma.

OBJECTIVES: This study utilizes Markov decision analysis to assess the relative benefits of prophylactic aortic valve replacement (AVR) at the time of coronary artery bypass graft surgery (CABG). Multiple sensitivity analyses were also performed to determine the variables that most profoundly affect outcome. BACKGROUND: The decision to perform CABG or concomitant CABG and AVR (CABG/AVR) in asymptomatic patients who need CABG surgery but have mild to moderate aortic stenosis (AS) is not clear-cut. METHODS: We performed Markov decision analysis comparing long-term, quality-adjusted life outcomes of patients with mild to moderate AS undergoing CABG versus CABG/AVR. Age-specific morbidity and mortality risks with CABG, CABG/AVR, and AVR after a prior CABG were based on the Society of Thoracic Surgeons national database (n = 1,344,100). Probabilities of progression to symptomatic AS, valve-related morbidity, and age-adjusted mortality rates were obtained from available published reports. RESULTS: For average AS progression, the decision to replace the aortic valve at the time of elective CABG should be based on patient age and severity of AS measured by echocardiography. For patients under age 70 years, an AVR for mild AS is preferred if the peak valve gradient is >25 to 30 mm Hg. For older patients, the threshold increases by 1 to 2 mm Hg/year, so that an 85-year-old patient undergoing CABG should have AVR only if the gradient exceeds 50 mm Hg. The AS progression rate also influences outcomes. With slow progression (<3 mm Hg/year), CABG is favored for all patients with AS gradients <50 mm Hg; with rapid progression (>10 mm Hg/year), CABG/AVR is favored except for patients >80 years old with a valve gradient <25 mm Hg. CONCLUSIONS: This study provides a decision aid for treating patients with mild to moderate AS requiring CABG surgery. Predictors of AS progression in individual patients need to be better defined.

Age Factors↗
PubMed2004

Procedural volume as a marker of quality for CABG surgery.

CONTEXT: There have been recent calls for using hospital procedural volume as a quality indicator for coronary artery bypass graft (CABG) surgery, but further research into analysis and policy implication is needed before hospital procedural volume is accepted as a standard quality metric. OBJECTIVE: To examine the contemporary association between hospital CABG procedure volume and outcome in a large national clinical database. DESIGN, SETTING, AND PARTICIPANTS: Observational analysis of 267 089 isolated CABG procedures performed at 439 US hospitals participating in the Society of Thoracic Surgeons National Cardiac Database between January 1, 2000, and December 31, 2001. MAIN OUTCOME MEASURE: Association between hospital CABG procedural volume and all-cause operative mortality (in-hospital or 30-day, whichever was longer). RESULTS: The median (interquartile range) annual hospital-isolated CABG volume was 253 (165-417) procedures, with 82% of centers performing fewer than 500 procedures per year. The overall operative mortality was 2.66%. After adjusting for patient risk and clustering effects, rates of operative mortality decreased with increasing hospital CABG volume (0.07% for every 100 additional CABG procedures; adjusted odds ratio [OR], 0.98; 95% confidence interval [CI], 0.96-0.99; P =.004). While the association between volume and outcome was statistically significant overall, this association was not observed in patients younger than 65 years or in those at low operative risk and was confounded by surgeon volume. The ability of hospital volume to discriminate those centers with significantly better or worse mortality was limited due to the wide variability in risk-adjusted mortality among hospitals with similar volume. Closure of up to 100 of the lowest-volume centers (ie, those performing < or =150 CABG procedures/year) was estimated to avert fewer than 50 of 7110 (<1% of total) CABG-related deaths. CONCLUSION: In contemporary practice, hospital procedural volume is only modestly associated with CABG outcomes and therefore may not be an adequate quality metric for CABG surgery.

Aged↗
PubMed2003

From controlled trials to clinical practice: monitoring transmyocardial revascularization use and outcomes.

OBJECTIVES: We sought to examine trends in the use and outcomes of transmyocardial revascularization (TMR) in community practice. We also identified important risk factors for TMR and compared outcomes of TMR combined with coronary artery bypass graft surgery (TMR + CABG) versus bypass alone in patients receiving incomplete revascularization. BACKGROUND: Although it is approved for use as a stand-alone procedure, there are limited data on the outcomes of (TMR + CABG). METHODS: We identified 3,717 patients receiving TMR at 173 U.S. hospitals participating in the Society of Thoracic Surgeons (STS) National Cardiac Database. Baseline characteristics and outcomes in these patients were compared with those from six published randomized TMR trials. Multivariable logistic regression was used to identify clinical risk factors for mortality with TMR. Risk-adjusted mortality was also compared for TMR + CABG relative to CABG only in patients not amenable to complete traditional revascularization. RESULTS: Between January 1998 and December 2001, the number of STS hospitals performing TMR and total procedural counts increased markedly, driven predominately by more TMR + CABG cases. Overall mortality rates for TMR-alone and TMR + CABG were 6.4% and 4.2%, respectively. Operative risks were significantly higher in those patients with recent myocardial infarction, unstable angina, and depressed ventricular function. Among patients receiving incomplete revascularization, TMR + CABG was not associated with decreased mortality risk compared with CABG alone, adjusted odds ratio 1.11 (95% confidence interval 0.74 to 1.67). CONCLUSIONS: The use of TMR, and in particular, TMR + CABG, is expanding in community practice. Although procedural risks are high, there is room for optimization through improved patient selection and timing of the procedure. Further studies of TMR + CABG are needed given its growing use and unclear benefits.

Aged↗
PubMed2003

Use of continuous quality improvement to increase use of process measures in patients undergoing coronary artery bypass graft surgery: a randomized controlled trial.

CONTEXT: A rigorous evaluation of continuous quality improvement (CQI) in medical practice has not been carried out on a national scale. OBJECTIVE: To test whether low-intensity CQI interventions can be used to speed the national adoption of 2 coronary artery bypass graft (CABG) surgery process-of-care measures: preoperative beta-blockade therapy and internal mammary artery (IMA) grafting in patients 75 years or older. DESIGN, SETTING, AND PARTICIPANTS: Three hundred fifty-nine academic and nonacademic hospitals (treating 267 917 patients using CABG surgery) participating in the Society of Thoracic Surgeons National Cardiac Database between January 2000 and July 2002 were randomized to a control arm or to 1 of 2 groups that used CQI interventions designed to increase use of the process-of-care measures. INTERVENTION: Each intervention group received measure-specific information, including a call to action to a physician leader; educational products; and periodic longitudinal, nationally benchmarked, site-specific feedback. MAIN OUTCOME MEASURE: Differential incorporation of the targeted care processes into practice at the intervention sites vs the control sites, assessed by measuring preintervention (January-December 2000)/postintervention (January 2001-July 2002) site differences and by using a hierarchical patient-level analysis. RESULTS: From January 2000 to July 2002, use of both process measures increased nationally (beta-blockade, 60.0%-65.6%; IMA grafting, 76.2%-82.8%). Use of beta-blockade increased significantly more at beta-blockade intervention sites (7.3% [SD, 12.8%]) vs control sites (3.6% [SD, 11.5%]) in the preintervention/postintervention (P =.04) and hierarchical analyses (P<.001). Use of IMA grafting also tended to increase at IMA intervention sites (8.7% [SD, 17.5%]) vs control sites (5.4% [SD,15.8%]) (P =.20 and P =.11 for preintervention/postintervention and hierarchical analyses, respectively). Both interventions tended to have more impact at lower-volume CABG sites (for interaction: P =.04 for beta-blockade; P =.02 for IMA grafting). CONCLUSIONS: A multifaceted, physician-led, low-intensity CQI effort can improve the adoption of care processes into national practice within the context of a medical specialty society infrastructure.

Adrenergic beta-Antagonists↗
PubMed2003

Use of mitral valve repair: analysis of contemporary United States experience reported to the Society of Thoracic Surgeons National Cardiac Database.

BACKGROUND: The Society of Thoracic Surgeons National Cardiac Database data indicate that the performance of mitral repair has increased significantly (1990 to 23.2%, 1999 to 32.0%, p < 0.0001). We examined contemporary (1999 to 2000) usage of mitral repair in the United States. METHODS: We analyzed National Cardiac Database data to determine the operative approach for a diagnosis of mitral regurgitation. RESULTS: A total of 21,741 isolated and combined mitral valve procedures were identified. The overall frequency of repair was 37.7% (8206). For procedures isolated to the mitral valve, the frequency of repair was 35.7% (3027/8486) whereas repair was more common with concomitant CABG (42.9% [3088/7193], p < 0.0001). The proportion of patients having repair decreased with age (41.2% [386/936] in 20 to 39 years, 36.1% [3513/9746] in > 70 years, p = 0.0016). Repair was more common in males (43.5% [4720/10860]) than females (32.0% [3472/10842], p < 0.0001). Repair was less common as NYHA Class increased (Class I, 47.8% [949/1984] vs Class IV, 33.2% [1803/5427]) and for emergent operative status (21.2% [156/736] vs 38.5% [8000/20773] for elective/urgent, both p < 0.0001). The number of prior operations did not affect the use of repair. Simple annuloplasty was performed in the majority of reported repairs (62.8% [3837/6115]), more so with associated CABG as compared to isolated repair (70.2% [2167/3088] vs 55.2% [1670/3027]; p < 0.0001). CONCLUSIONS: Mitral repair was performed in over one-third of the patients reported in 1999 to 2000 and has increased since the National Cardiac Database inception. Repair usage differed based on sex, age, gravity of illness, and associated procedures. This provides a base line from which to expand the application of repair.

Adult↗
PubMed2003

The Society of Thoracic Surgeons: 30-day operative mortality and morbidity risk models.

BACKGROUND: Although 30 day risk-adjusted operative mortality (ROM) has been used for quality assessment, it is not sufficient to describe the outcomes after coronary artery bypass grafting (CABG) surgery. Risk-adjusted major morbidity may differentially impact quality of care (as complications occur more frequently than death) and enhance a surgical team's ability to assess their quality. This study identified the preoperative risk factors associated with several complications and a composite outcome (the presence of any major morbidity or 30-day operative mortality or both). METHODS: For CABG procedures, the 1997 to 1999 Society of Thoracic Surgeons (STS) National Adult Cardiac Surgery Database was used to develop ROM and risk-adjusted morbidity (ROMB) models. Risk factors were selected using standard STS univariate screening and multivariate logistic regression approaches. Risk model performance was assessed. Across STS participating sites, the association of observed-to-expected (O/E) ratios for ROM and ROMB was evaluated. RESULTS: The 30-day operative death and major complication rates for STS CABG procedures were 3.05% and 13.40%, respectively (503,478 CABG procedures), including stroke (1.63%), renal failure (3.53%), reoperation (5.17%), prolonged ventilation (5.96%), and sternal infection (0.63%). Risk models were developed (c-indexes for stroke [0.72], renal failure [0.76], reoperation [0.64], prolonged ventilation [0.75], sternal infection [0.66], and the composite endpoint [0.71]). Only a slight correlation was found, however, between ROMB and ROM indicators. CONCLUSIONS: Used in combination, ROMB and ROM may provide the surgical team with additional information to evaluate the quality of their care as well as valuable insights to allow them to focus on areas for improvement.

Aged↗
PubMed2003

Effects of controlled antegrade pulmonary blood flow on cardiac function after bidirectional cavopulmonary anastomosis.

BACKGROUND: Bidirectional cavopulmonary anastomosis (BCPA) has been used as an intermediate stage in the treatment of patients with single-ventricle physiology. Leaving additional antegrade pulmonary blood flow has been shown to improve postoperative arterial blood oxygen saturations; however, controversy continues over whether the potential increase in systemic venous pressure is detrimental. We studied the effects of controlled antegrade pulmonary blood flow on cardiac function in patients after BCPA. METHODS: From January 1993 to July 2000, 128 patients underwent BCPA. Mean age at operation was 6.2 +/- 4 months (range 2 to 36 months). In group 1 (n = 72), restricted antegrade pulmonary blood flow was maintained through a native narrowed pulmonary valve or by adjustment of previously placed pulmonary artery band with the goal of maintaining the mean pulmonary artery pressure less than 16 mm Hg. In group 2 (n = 56), BCPA was the only source of pulmonary blood flow. RESULTS: One hospital death (0.8%) occurred. The mean pulmonary artery pressure at the end of the operation was 13 +/- 2 mm Hg in group 1 compared with 12 +/- 2 mm Hg in group 2, a difference that was not significant. Patients in group 1 had higher arterial oxygen saturations (84% +/- 3% compared with 74% +/- 3% in group 2, p < 0.05), and shorter mean hospital stay (9 +/- 3 days compared with 15 +/- 2 days, p < 0.05). Persistent pleural effusion (> 10 days) or late chylothorax occurred in 4 patients from group 1 and 3 from group 2, a difference that was not significant. During a mean follow-up of 36 +/- 10 months no late deaths occurred. The mean oxygen saturation remained higher in group 1, 80% +/- 3% compared with 74% +/- 4% in group 2, and the hematocrit was lower, at 38% +/- 3% compared with 46% +/- 4% (p < 0.05 for both comparisons). Cardiac catheterizations were performed in 68 patients before completion Fontan. Total pulmonary artery (Nakata) index was 263 +/- 34 mm(2)/m(2) in group 1 (n = 40) and 188 +/- 13 mm(2)/m(2) in group 2 (n = 28) (p < 0.05). The mean pulmonary artery pressure and mean ventricular end-diastolic pressure were similar. CONCLUSIONS: Controlled antegrade pulmonary blood flow may have favorable effects on cardiac function for a selected group of patients and does not appear to have adverse effects on subsequent suitability for completion Fontan.

Blood Pressure↗
PubMed2003

Cardiac surgery in nonagenarians and centenarians.

BACKGROUND: Nonagenarians and centenarians are a rapidly growing segment of the population. No previous study has used a national database to compare outcomes in these patients to those of other groups undergoing cardiac surgical procedures. STUDY DESIGN: The Society of Thoracic Surgeons National Database was used to review retrospectively 662,033 patients (5 patients more than 100 years of age; 1,092 patients 90 to 99 years; 59,576 patients 80 to 89 years; and 621,360 patients 50 to 79 years of age) who underwent cardiac surgical procedures from 1997 through 2000. These included 575,389 patients who had undergone coronary artery bypass grafting (CABG) only; 56,915 patients with CABG and concomitant mitral or aortic valve replacement or repair (CABG+VALVE); and 49,729 patients with mitral or aortic valve repair or replacement only (VALVE-only). A multivariate logistic regression model was developed to examine predictors of operative mortality in patients more than 90 years of age. RESULTS: For CABG-only patients, operative mortality was 11.8% for patients more than 90 years of age, 7.1% for those 80 to 89 years, and 2.8% for those 50 to 79 years. The incidence of renal failure and prolonged ventilation was highest among patients more than 90 years of age (9.2% and 12.2%), compared with those 80 to 89 years (7.7% and 10.5%) or 50 to 79 years (3.5% and 6.0%). For VALVE-only patients and CABG+VALVE patients operative mortality for those more than 90 years of age was 11.4% and 12.0%, respectively, compared with 8.3% and 11.5% for those 80 to 89 years and 4.3% and 7.6% for those 50 to 79 years. The major preoperative risk factors for operative mortality among patients more than 90 years of age undergoing isolated CABG were as follows (C-index, 0.68): emergent/salvage: odds ratio, 2.26; 95% confidence interval, 1.38-3.69; preoperative intraaortic balloon pump: odds ratio, 2.79; 95% confidence interval, 1.47-5.32; renal failure: odds ratio, 2.08; 95% confidence interval, 1.12-3.86; peripheral vascular disease or cerebrovascular vascular disease: odds ratio, 1.39, 95% confidence interval, 0.96-2.02; mitral insufficiency: odds ratio, 1.50; 95% confidence interval, 0.93-2.41. Approximately 57% of the nonagenarians and centenarians lacked any of the first four risk factors and had an operative mortality of 7.2%. CONCLUSIONS: Operative mortality and complication rates associated with cardiac surgical procedures are highest for nonagenarians and centenarians. But with careful patient selection, a majority of these patients have a lower risk of CABG-related mortality approaching that of younger patients.

Age Factors↗