Chronic exposure to nicotine does not prevent neurocognitive decline after cardiac surgery
ABSTRACT To establish the association between smoking and cognitive decline in patients undergoing coronary artery bypass graft (CABG) surgery.
Referral center for cardiothoracic surgery at a university hospital.
Four hundred seventeen patients undergoing CABG surgery.
Based on preoperative data, patients were divided into 2 groups: smokers (n = 185) and nonsmokers (n = 232). Patients who smoked half a pack of cigarettes per day within the last 2 years were identified as smokers, and patients who did not smoke were included in the nonsmoker group. Patients with less than a seventh grade education; an inability to read; or a history of one of the following medical conditions: prior stroke with residual deficit, psychiatric illness, renal disease (creatinine > 2.0 mg/dL), or active liver disease; or patients who quit smoking prior to surgery were excluded from the study. Both groups received similar anesthetic and surgical management. All patients received a battery of neurocognitive tests both preoperatively and 6 weeks after CABG surgery. Neurocognitive test scores were separated into 4 cognitive domains, with a composite cognitive index (the mean of the four domain scores) determined for each patient at every testing period.
The overall rate of cognitive decline at 6 weeks after surgery in smokers was 36.2%, whereas nonsmokers showed a deficit rate of 36.6%. Nonsmokers were significantly older and presented for surgery on average 6 years later than the smokers. Female sex represented a considerably larger proportion of patients in the nonsmoker group. Smokers had a higher prevalence of myocardial infarction. The univariate analysis of cognitive change at 6 weeks adjusted for age, baseline cognitive index, and education years showed no difference between the 2 groups. Sex, history of myocardial infarction, hypertension, stroke, transient ischemic attack, and duration of cardiopulmonary bypass did not contribute to the multivariate logistic regression model and were dropped from the final analysis. Significant multivariate predictors of neurocognitive dysfunction included age, left ventricular ejection fraction, baseline education level, and baseline cognitive index.
This study confirmed previous findings that age, baseline cognitive function, years of education, and impaired left ventricular function are independent predictors of neurocognitive decline at 6 weeks after CABG surgery. Smoking is neither preventive nor causative of cognitive decline after CABG surgery.
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ABSTRACT: Hintergrund und Ziel:Der Anteil aktiver Raucher in der koronaren Bypasschirurgie nimmt zu. Das Ziel dieser Studie war, die Wirkung des Raucherstatus auf die postoperativen Ergebnisse und Ereignisse zu untersuchen.Patienten und Methodik:Zwischen April 1997 und Mrz 2003 wurden 6 367 Patienten einer chirurgischen Myokardrevaskularisation unterzogen. Zur Risikoadjustierung wurden die von der American Heart Association und dem American College of Cardiology vorgeschlagenen Parameter bercksichtigt. Unter Zuhilfenahme der logistischen Regression, Cox-Proportional-Hazards-Analyse sowie der Kaplan-Meier-Methode wurden die operativen Ergebnisse untersucht.Ergebnisse:947 Patienten (14,9%) rauchten noch in den letzten 4 Wochen vor der Operation, 3 857 (60,6%) waren Exraucher (mindestens 4 Wochen vor der Operation aufgehrt) und 1 563 (24,5%) Nichtraucher. Nach Risikoadjustierung zeigten aktive Raucher eine erhhte Neigung zu pulmonalen Infektionen (p < 0,001) sowie Atelektasenbildung (p < 0,001), bentigten hufiger eine postoperative maschinelle Beatmung > 48 h (p = 0,003) und tendierten mehr zur einer intensivmedizinischen Behandlung > 3 Tage (p < 0,001). Die Krankenhausletalitt zeigte bei den drei Gruppen keinen signifikanten Unterschied. Whrend die Exraucher bei der Verlaufskontrolle in den ersten 4 Jahren keine hhere Letalittsrate zeigten (p = 0,11), war die Letalittsrate bei Rauchern signifikant erhht (p = 0,029).Schlussfolgerung:Raucher neigen zu erhhten pulmonalen Komplikationen und lngerem Aufenthalt auf der Intensivstation. Obwohl die Krankenhausletalitt hiervon nicht signifikant beeinflusst wird, profitieren die Patienten im Langzeitverlauf von der Aufgabe des Rauchens.Background and Purpose:The proportion of patients undergoing coronary artery bypass surgery (CABG) with a history of smoking is increasing. The aim of this study was to examine the effect of smoking on outcomes following CABG.Patients and Methods:6,367 consecutive patients who underwent CABG between April 1997 and March 2003 were analyzed retrospectively. Logistic regression was used to risk-adjust inhospital outcomes, while Cox proportional hazards analysis was used to risk-adjust Kaplan-Meier survival curves. Outcomes were adjusted for variables suggested by the American Heart Association and the American College of Cardiology.Results:947 patients (14.9%) were current smokers (smoking within 1 month of surgery), while 3,857 (60.6%) were ex-smokers and 1,563 (24.5%) nonsmokers. After adjusting for differences in case-mix, current smokers were more likely to develop chest infections (p < 0.001), atelectasis (p < 0.001), and require ventilation > 48 h (p = 0.003). Current smokers were also more likely to stay in intensive care for > 3 days (p < 0.001). There was no association between smoking status and in-hospital mortality. Ex-smokers were not associated with excess mortality (p = 0.11), while current smokers had significantly increased mortality during follow-up (p = 0.029).Conclusion:Current smokers are associated with increased respiratory complications, and prolonged stay on intensive care. Although not associated with in-hospital mortality, there appears to be a significant increase in mortality in smokers during a 4-year follow-up period. Patients should be encouraged to stop smoking to maximize the long-term benefits of CABG.Herz 04/2004; 29(3):310-316. DOI:10.1007/s00059-004-2573-5 · 0.91 Impact Factor
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ABSTRACT: The presence of new ischemic brain infarcts, detected by diffusion-weighted magnetic resonance imaging (DW-MRI), have been reported in considerable number of patients after cardiac surgery. We sought to determine the role of proximal thoracic aortic atheroma in predicting embolic events and new ischemic brain lesions in patients undergoing conventional coronary revascularization surgery. Transesophageal echocardiography and epiaortic scanning was performed to assess the severity of aortic atherosclerosis in the ascending aorta and the aortic arch. Patients were allocated to either low-risk group, (intimal thickness < or =2mm), or high-risk group (intimal thickness >2mm). Transcranial Doppler was used to monitor the middle cerebral artery. DW-MRI was performed 3-7 days after surgery. The NEECHAM Confusion Scale was used for assessment and monitoring patient consciousness level. Patients in the high-risk group were considerably older; 71+/-6 (n=38) versus 67+/-6 (n=72) years, P=0.004 and were more likely to have impaired left ventricular function. Confusion was present in 6 (16%) patients in the high-risk group and 5 (7%) patients in the low-risk group. Patients in the high-risk group had a three-fold increase in median embolic count, 223.5 versus 70.0, P=0.0003. DW-MRI detected brain lesions were only present in patients from high-risk group, 61.5 versus 0%, P<0.0001. There was significant correlation between the NEECHAM scores and embolic count in the high-risk group; r=0.63, P<0.001. The findings of this investigation suggest that mild to moderate atheromatous disease of the ascending aorta and the aortic arch (intimal thickness >2mm) is a major contributor to ischemic brain injury after cardiac surgery.Stroke 09/2004; 35(9):e356-8. DOI:10.1161/01.STR.0000138783.63858.62 · 6.02 Impact Factor
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ABSTRACT: We aimed to examine the effect of smoking on outcomes following coronary artery bypass grafting (CABG). We retrospectively analysed 6 367 consecutive patients who underwent CABG between April 1997 and March 2003. Logistic regression was used to risk adjust in-hospital outcomes, while Cox proportional hazards analysis was used to risk adjust Kaplan-Meier survival curves. Outcomes were adjusted for variables suggested by the American Heart Association and American College of Cardiology. 947 (14.9 %) patients were current smokers (smoking within 1 month of surgery), while 3857 (60.6 %) were ex-smokers and 1 563 (24.5 %) were non-smokers. After adjusting for differences in case-mix, current smokers were more likely to develop chest infections ( p < 0.001), atelectasis ( p < 0.001), and require ventilation longer than 48 hours ( p = 0.003). Current smokers were also more likely to stay in intensive care for more than 3 days ( p < 0.001). Ex-smokers were not associated with excess mortality ( p = 0.11), while current smokers had significantly increased mortality during follow-up ( p = 0.029). Patients should be encouraged to stop smoking to maximise the long-term benefits of CABG.The Thoracic and Cardiovascular Surgeon 11/2004; 52(5):268-73. DOI:10.1055/s-2004-821103 · 1.08 Impact Factor