Daniel J.M. Keenan

Neurological outcomes in coronary surgery: independent effect of avoiding cardiopulmonary bypass.

BACKGROUND Recent studies examining neuroprotective effects of off-pump coronary artery bypass grafting (CABG) have shown inconsistent results. We examined our database to quantify the independent effects of avoidance of cardiopulmonary bypass (CPB) and aortic manipulation on neurologic outcomes after CABG. METHODS A total of 2,327 consecutive cases undergoing isolated CABG between April 1997 and May 2001 were identified at our two institutions. Patients were divided into three groups: on CPB, off-pump with aortic manipulation, and off-pump without aortic manipulation. To control for the confounding effects of other risk factors, we performed a multivariate logistic regression analysis. Potential covariates considered in the logistic model included age, sex, redo operations, diabetes, chronic obstructive pulmonary disease, neurologic disease, peripheral vascular disease, ejection fraction, and priority of operation. RESULTS A total of 1,210 cases were performed on CPB, compared with 520 off-pump with aortic manipulation, and 597 off-pump without aortic manipulation. The incidence of focal neurologic deficit was 1.6% (n = 19) in the on-pump group, 0.4% (n = 2) in the off-pump with aortic manipulation group, and 0.5% (n = 3) for the off-pump without aortic manipulation group (p for trend = 0.027). The results of the multivariate logistic regression analysis demonstrated that use of CPB was a risk factor for focal neurologic deficit, with an odds ratio of 3.82 (95% confidence interval, 1.41 to 10.34; p = 0.005). Aortic manipulation did not significantly influence neurologic outcome in off-pump patients. CONCLUSIONS Off-pump operation, with or without aortic manipulation, reduces adverse neurologic outcomes compared with on-pump procedures.

Off-pump Coronary Artery Bypass (OPCAB) surgery reduces risk-stratified morbidity and mortality: A United Kingdom multi-center comparative analysis of early clinical outcome

Objective—Off-Pump Coronary Artery Bypass (OPCAB) surgery is gaining more popularity worldwide. The aim of this United Kingdom (UK) multi-center study was to assess the early clinical outcome of the OPCAB technique and perform a risk-stratified comparison with the conventional Coronary Artery Bypass Grafting (CABG) using the Cardio-Pulmonary Bypass (CPB) technique. Methods—Data were collected on 5,163 CPB patients from the database of the National Heart and Lung institute, Imperial College, University of London, and on 2,223 OPCAB patients from eight UK cardiac surgical centers, which run established OPCAB surgery programs. All patients had undergone primary isolated CABG for multi-vessel disease through a midline sternotomy approach, between January 1997 and April 2001. Postoperative morbidity and mortality were compared between the CPB and OPCAB patients after adjusting for case-mix. The mortality of the OPCAB patients was also compared, using risk stratification, to the mortality figures reported by the Society of Cardiothoracic Surgeons of Great Britain and Ireland (SCTS) based on 28,018 patients in the national database who were operated on between January 1996 and December 1999. Results—Morbidity and mortality were significantly lower in the OPCAB patients compared with the CPB patients and the UK national database of CABG patients, over the same period of time, after adjusting for case-mix. Conclusion—This study demonstrates that risk stratified morbidity and mortality are significantly lower in OPCAB patients than CPB patients and patients in the UK national database.

Good outcomes from cardiac surgery in the over 70s

OBJECTIVE To determine the early mortality and major morbidity associated with cardiac surgery in the elderly. DESIGN Retrospective case record review study of 575 patients ⩾ 70 years old who underwent cardiac surgery at the Manchester Heart Centre between January 1990 and December 1996. SETTING Regional cardiothoracic centre. SUBJECTS Patients ⩾ 70 years old who underwent cardiac surgery. MAIN OUTCOME MEASURES Comparison of 30 day mortality and incidence of major morbidity between patients ⩾ 70 years old and patients < 70 years old. RESULTS Of 4395 cardiac surgical operations, 575 operations (13.1%) were in patients aged ⩾ 70 years (mean (SD) 73.1 (3.2) years). The proportion of elderly patients rose progressively from 7.9% in 1990 to 16.5% in 1996. 334 patients (58.1%) had coronary artery bypass grafting alone, 91 patients (15.8%) had valve surgery alone, and 129 patients (22.4%) had combined valve surgery and bypass grafting. For isolated coronary artery bypass grafting, 30 day mortality in patients ⩾ 70 years was 3.9% compared with 1.3% in patients < 70 years (p < 0.001). 30 day mortality for isolated valve surgery in patients ⩾ 70 years was 7.7%. Isolated aortic valve replacement was the most common valvar procedure in patients ⩾ 70 years and carried the lowest mortality (4.3%). Additional coronary artery bypass grafting increased the mortality rate in patients ⩾ 70 years to 9.3% for all valve surgery and to 8.0% for aortic valve replacement. Major morbidity in patients ⩾ 70 years was low for all procedure types (stroke 1.9%, acute renal failure requiring dialysis 1.6%, perioperative myocardial infarction 0.5%). CONCLUSIONS Early mortality and major morbidity is low for cardiac surgery in elderly patients. Concerns over the risk of cardiac surgery in the elderly should not prevent referral, and elderly patients usually do well. However, unconscious rationing of health care may affect referral patterns, and studies that assess the cost effectiveness of cardiac surgery versus conservative management in such patients are lacking.

Social deprivation and prognostic benefits of cardiac surgery: observational study of 44 902 patients from five hospitals over 10 years

Objective To assess the effects of social deprivation on survival after cardiac surgery and to examine the influence of potentially modifiable risk factors. Design Analysis of prospectively collected data. Prognostic models used to examine the additional effect of social deprivation on the end points. Setting Birmingham and north west England. Participants 44 902 adults undergoing cardiac surgery, 1997-2007. Main outcome measures Social deprivation with census based 2001 Carstairs scores. All cause mortality in hospital and at mid-term follow-up. Results In hospital mortality for all cardiac procedures was 3.25% and mid-term follow-up (median 1887 days; range 1180-2725 days) mortality was 12.4%. Multivariable analysis identified social deprivation as an independent predictor of mid-term mortality (hazard ratio 1.024, 95% confidence interval 1.015 to 1.033; P<0.001). Smoking (P<0.001), body mass index (BMI, P<0.001), and diabetes (P<0.001) were associated with social deprivation. Smoking at time of surgery (1.294, 1.191 to 1.407, P<0.001) and diabetes (1.305, 1.217 to 1.399, P<0.001) were independent predictors of mid-term mortality. The relation between BMI and mid-term mortality was non-linear and risks were higher in the extremes of BMI (P<0.001). Adjustment for smoking, BMI, and diabetes reduced but did not eliminate the effects of social deprivation on mid-term mortality (1.017, 1.007 to 1.026, P<0.001). Conclusions Smoking, extremes of BMI, and diabetes, which are potentially modifiable risk factors associated with social deprivation, are responsible for a significant reduction in survival after surgery, but even after adjustment for these variables social deprivation remains a significant independent predictor of increased risk of mortality.

Validation of four different risk stratification systems in patients undergoing off-pump coronary artery bypass surgery: a UK multicentre analysis of 2223 patients

Background: Various risk stratification systems have been developed in coronary artery bypass graft surgery (CABG), based mainly on patients undergoing procedures with cardiopulmonary bypass. Objective: To assess the validity and applicability of the Parsonnet score, the EuroSCORE, the American College of Cardiology/American Heart Association (ACC/AHA) system, and the UK CABG Bayes model in patients undergoing off-pump coronary artery bypass surgery (OPCAB) in the UK. Methods: Data on 2223 patients who underwent OPCAB in eight cardiac surgical centres were collected. Predicted mortality risk scores were calculated using the four systems and compared with observed mortality. Calibration was assessed by the Hosmer–Lemeshow (HL) test. Discrimination was assessed using the receiver operating characteristic (ROC) curve area. Results: 30 of 2223 patients (1.3%) died in hospital. For the Parsonnet score the HL test was significant (p < 0.001) and the receiver operating characteristic curve (ROC) area was 0.74. For the EuroSCORE the HL test was also significant (p = 0.008) and the ROC area was 0.75. For the ACC/AHA system the HL test was non-significant (p = 0.7) and the ROC area was 0.75. For the UK CABG Bayes model the HL test was also non-significant (p = 0.3) and the ROC area was 0.81. Conclusions: The UK CABG Bayes model is reasonably well calibrated and provides good discrimination when applied to OPCAB patients in the UK. Among the other three systems, the ACC/AHA system is well calibrated but its discrimination power was less than for the UK CABG Bayes model. These data suggest that the UK CABG Bayes model could be an appropriate risk stratification system to use for patients undergoing OPCAB in the UK.

Effect of avoiding cardiopulmonary bypass in non-elective coronary artery bypass surgery: a propensity score analysis

OBJECTIVE Non-elective coronary artery surgery (emergent/salvage or urgent) carries an increased risk in most risk-stratification models. Off-pump coronary surgery is increasingly used in non-elective cases. We aimed to investigate the effect of avoiding cardiopulmonary bypass on outcomes following non-elective coronary surgery. METHODS Of the 3771 consecutive coronary artery bypass procedures performed by five surgeons between April 1997 and March 2002, 828 (22%) were non-elective and 417 (50.4%) of these patients had off-pump surgery. Multivariate logistic regression was used to assess the effect of off-pump on in-hospital outcomes, while adjusting for treatment selection bias. Treatment selection bias was controlled for by constructing a propensity score from core patient characteristics, which was the probability of avoiding cardiopulmonary bypass. The C statistic for this model was 0.8. RESULTS Off-pump patients were more likely to be hypertensive, stable, had less extensive disease and better left ventricular function. The left internal mammary artery was used in 91.8% (n=383) of off-pump patients compared to 79.3% (n=326) of on-pump cases (P<0.001). After adjusting for the propensity score, no difference in in-hospital mortality was observed between off-pump and on-pump (adjusted odds ratio (OR) 0.83 (95% confidence intervals (CI) 0.36-1.93); P=0.667). Off-pump patients were less likely to require intra-aortic balloon pump support (adjusted OR 0.44 (95% CI 0.21-0.96); P=0.039), less likely to have renal failure (adjusted OR 0.44 (95% CI 0.22-0.90); P=0.025), and have shorter lengths of stay (adjusted OR 0.51 (95% CI 0.37-0.70); P<0.001). Other morbidity outcomes were similar in both groups. CONCLUSIONS In this experience, off-pump coronary surgery in non-elective patients is safe with acceptable results. Non-elective off-pump patients have a significantly reduced incidence of renal failure, and shorter post-operative stays compared to on-pump coronary artery bypass surgery.

Early and late results following combined coronary bypass surgery and mitral valve replacement

To study the effect of various perioperative and operative variables, we analysed the results of 66 consecutive patients undergoing mitral valve replacement (MVR) and coronary artery bypass grafting (CABG). The mean age was 61.2 years (34 males and 32 females), the mean follow-up 54.71 +/- 7.8 months. The hospital mortality rate was 7.6% (5/66). New York Heart Association (NYHA) functional class (P < 0.01), left ventricular global wall motion score (increased scores indicating impaired function, P = 0.005) and cross-clamp time (P < 0.05) were associated with hospital mortality. There was no significant relationship of age (certainly up to the age of 70), cause of mitral valve disease, severity of mitral regurgitation, number of grafts, presence of angina, or previous myocardial infarction with hospital mortality. There were eight late deaths, survival at 1, 3 and 5 years was 92.4%, 83.2% and 80.2%, respectively. Although there was a trend for pulmonary vascular resistance (P = 0.15), NYHA class (P = 0.18) and aortic cross-clamp time (P = 0.09) to be associated with late survival, the only factor significantly related to late survival was global wall motion score (P = 0.001), i.e. those with scores of more than 10. Severity of mitral regurgitation and cause of mitral valve disease have been reported as being related to late survival in patients undergoing combined CABG and MVR, but we have found no such relationship. Our results indicate that both hospital and late mortality after this operation are strongly correlated with left ventricular function.

Hypoglycaemia associated with a solitary fibrous tumour of the pleura

We report the interesting case of an elderly woman who presented with hypoglycaemic episodes and weight loss. She was found to have a solitary fibrous tumour weighing more than 1.7 kg arising from the diaphragmatic pleura, which had been producing insulin-like growth factor II. After surgical removal of this well-encapsulated, pedunculated tumour her hypoglycaemia resolved and she returned to normal both clinically and biochemically.

Overdose of tetracycline for pleurodesis leading to chemical burns of the pleura

Chemical pleurodesis using tetracycline is an accepted and commonly employed treatment of pneumothorax and pleural effusions. We describe a case of chemical burn of the pleura in a ventilated 41-year-old who came to thoracotomy after 3 days of continuous intrapleural infusion of tetracycline at another hospital. To our knowledge this has not been previously reported although other adverse effects of this procedure are documented. We suggest that damage to the pleura and underlying lung may occur if excessive amounts of tetracycline are used in attempted pleurodesis.

A meta-analysis of computerized tomography scan for reducing complications following repeat sternotomy for cardiac surgery

Cardiac reoperation carries additional risks compared with surgery in patients who are sternotomy-naïve. To identify if preoperative computerized tomography (CT) can reduce this risk, we performed a systematic review of the literature and meta-analysis. Literature search identified 178 studies of which 4 retrospective cohort studies incorporating 900 patients met inclusion criteria. There were no statistically significant differences in the risk of death, re-entry injury, renal failure or perfusion/ischaemic times. CT scan reduced the risk of stroke by 0.42 [95% confidence interval (CI): 0.19-0.93, P = 0.03] and a composite of major complications by 0.65 (95% CI: 0.47-0.88, P = 0.006). The use of preoperative cross-sectional imaging to reduce the risk of complications following cardiac reoperation is advocated.