Effect of Smoking on Short-Term Outcome of Patients Undergoing Coronary Artery Bypass Surgery

Impact of smoking on the outcomes of minimally invasive direct coronary artery bypass

BACKGROUND

Tobacco smoking has been associated with an increased risk of complications after conventional coronary surgery. However, the impact of smoking on the risk of postoperative complications in minimally invasive coronary surgery is yet to be studied. We aimed to analyze the impact of the preoperative smoking status on the short- and long-term outcomes of minimally invasive direct coronary artery bypass grafting (MIDCAB) in the context of isolated surgical revascularization or in association with percutaneous coronary intervention.

METHODS

This was a retrospective observational study of all patients undergoing MIDCAB at our institution between 2006 and 2020. Patients were divided into three groups: active smokers, ex-smokers who have quit smoking for at least 1 month before surgery, and non-smokers. The groups were compared using conventional statistical methods. Multivariate analysis was then performed where significant differences were found to eliminate bias.

RESULTS

Throughout the study period, 541 patients underwent MIDCAB, of which 135 (25%) were active smokers, 183 (34%) were ex-smokers, and 223 (41%) were non-smokers. Smokers presented for surgery at a younger age (p < 0.0001), more frequently with a history of myocardial infarction (p < 0.001), peripheral artery disease (p < 0.001) and chronic obstructive pulmonary disease (p < 0.0001). Using multivariate analysis, active smoking was determined to be a significant risk factor for the need of urgent revascularization (odds ratio 2.36 [1.00-5.56], p = 0.049) and the composite of pulmonary complications (including pneumothorax, respiratory infection, respiratory dysfunction, subcutaneous emphysema and exacerbation of chronic obstructive pulmonary disease; odds ratio 2.84 [1.64-4.94], p < 0.001). Preoperative smoking status did not influence the long-term survival (p = 0.83).

CONCLUSIONS

In our study, active smokers presented for MIDCAB at a younger age and more often with signs of atherosclerotic disease (history of myocardial infarction and peripheral artery disease). Active smoking was found to be the most significant risk factor for postoperative pulmonary complications, and is also associated with a more frequent need for urgent surgery at diagnosis. Long-term postoperative survival is not affected by the preoperative smoking status.

Pneumonia After Cardiovascular Surgery: Incidence, Risk Factors and Interventions

Postoperative pneumonia (POP) is prevalent in patients undergoing cardiovascular surgery, associated with poor clinical outcomes, prolonged hospital stay and increased medical costs. This article aims to clarify the incidence, risk factors, and interventions for POP after cardiovascular surgery. A comprehensive literature search was performed to identify previous reports involving POP after cardiovascular surgery. Current situation, predictors and preventive measures on the development of POP were collected and summarized. Many studies showed that POP was prevalent in various cardiovascular surgical types, and predictors varied in different studies, including advanced age, smoking, chronic lung disease, chronic kidney disease, cardiac surgery history, cardiac function, anemia, body mass index, diabetes mellitus, surgical types, cardiopulmonary bypass time, blood transfusion, duration of mechanical ventilation, repeated endotracheal intubation, and some other risk factors. At the same time, several targeted interventions have been widely reported to be effective to reduce the risk of POP and improve prognosis, including preoperative respiratory physiotherapy, oral care and subglottic secretion drainage. Through the review of the current status, risk factors and intervention measures, this article may play an important role in clinical prevention and treatment of POP after cardiovascular surgery.

Development and validation of a risk prediction model for postoperative pneumonia in adult patients undergoing Stanford type A acute aortic dissection surgery: a case control study

Background

Pneumonia is a common complication after Stanford type A acute aortic dissection surgery (AADS) and contributes significantly to morbidity, mortality, and length of stay. The purpose of this study was to identify independent risk factors associated with pneumonia after AADS and to develop and validate a risk prediction model.

Methods

Adults undergoing AADS between 2016 and 2019 were identified in a single-institution database. Patients were randomly divided into training and validation sets at a ratio of 2:1. Preoperative and intraoperative variables were included for analysis. A multivariate logistic regression model was constructed using significant variables from univariate analysis in the training set. A nomogram was constructed for clinical utility and the model was validated in an independent dataset.

Results

Postoperative pneumonia developed in 170 of 492 patients (34.6%). In the training set, multivariate analysis identified seven independent predictors for pneumonia after AADS including age, smoking history, chronic obstructive pulmonary disease, renal insufficiency, leucocytosis, low platelet count, and intraoperative transfusion of red blood cells. The model demonstrated good calibration (Hosmer–Lemeshow χ² = 3.31, P = 0.91) and discrimination (C-index = 0.77) in the training set. The model was also well calibrated (Hosmer–Lemeshow χ² = 5.73, P = 0.68) and showed reliable discriminatory ability (C-index = 0.78) in the validation set. By visual inspection, the calibrations were good in both the training and validation sets.

Conclusion

We developed and validated a risk prediction model for pneumonia after AADS. The model may have clinical utility in individualized risk evaluation and perioperative management.

Preoperative patient factors associated with blood product use in cardiac surgery, a retrospective cohort study

BACKGROUND

Cardiac surgery is associated with a high rate of blood use. The aim of this study is to identify preoperative patient factors associated with allogeneic Red Blood Cell (RBC) or non-Red Blood Cell (NRBC) use in cardiac surgery.

METHODS

All adult cardiac surgical procedures conducted at a single Western Australian institution were retrospectively analysed. Data was collected from the Australia and New Zealand Cardiac Surgery Database from 2015 to 2018. A number of preoperative factors were identified, relating to past medical history or preoperative cardiac status. Outcome 1 was defined as the use of one or more RBC products intra or post-operatively. Outcome 2 was defined as the use of one or more NRBC products intra or post-operatively. Multivariate logistical regression analysis was done to assess for the association between preoperative factors and allogeneic blood product use.

RESULTS

A total of 1595 patients were included in this study, of which 1488 underwent a Coronary Artery Bypass Graft, Valve or a combined procedure. Patients on dialysis preoperatively and those who had preoperative cardiogenic shock demonstrated the greatest risk of requiring RBC transfusion with an odds ratio of 5.643 (95% CI 1.305-24.40) and 3.257 (95% 1.801-5.882) respectively. Patients who had preoperative cardiogenic shock demonstrated the greatest risk of requiring NRBC transfusion with an odds ratio of 3.473 (95% CI 1.970-6.135). Patients who have had a previous cardiothoracic intervention are at increased risk of both RBC and NRBC transfusion, with adjusted odds ratios of 1.774 (95% CI 1.353-2.325) and 2.370 (95% CI 1.748-3.215) respectively.

CONCLUSION

A number of factors relating to past medical history or preoperative cardiac status are implicated with increased allogeneic blood product use in cardiac surgery. Identifying high-risk patients in a preoperative setting can enable us enrol them in a blood conservation program, therefore minimizing the risk of exposure to blood transfusion.

Comparison of surgical invasiveness and morbidity of adult spinal deformity surgery to other major operations

BACKGROUND CONTEXT

Adult spinal deformity (ASD) surgeries are complex, involving long operative times and surgical morbidity. It is currently unclear how the invasiveness of ASD surgery compares to other major operations.

PURPOSE

To: (1) develop a quantitative score of surgical morbidity and invasiveness, and (2) compare this score between ASD surgery and other major operations.

STUDY DESIGN

Retrospective review of prospectively collected data.

PATIENT SAMPLE

A prospective surgical registry was used to identify all patients undergoing ASD surgery involving ≥ 7 segments. Seventeen additional procedures were included: coronary artery bypass grafting (CABG), pancreatectomy, and esophagectomy, among others.

OUTCOME MEASURES

Perioperative factors (operative time, transfusions, ventilation) and complications were collected and combined with a previously validated Postoperative Morbidity Survey to create a Surgical Invasiveness and Morbidity Score (SIMS).

METHODS

Computed scores were compared across surgeries using Welch's t-test. Multiple linear regression modeling was used to compare the SIMS of major surgeries relative to ASD while controlling for patient demographics and comorbidities.

RESULTS

A total of 1,245,282 surgical patients were included, 4,656 of which underwent ASD surgery. After multiple regression modeling controlling for patient demographics and comorbidities, ASD surgery ranked fourth in SIMS. ASD surgery had a significantly greater SIMS than 13 other major procedures including 6th esophagectomy (adjusted mean difference=-0.05, 95%CI -0.01-0.09, p<.001), 8th pancreatectomy (-0.40, 0.37-0.44, p<.001), 11th craniotomy for tumor (-1.01, 0.98-1.04, p<.001), and 12th sacral chordoma resection (-1.31, 1.26-1.37, p<.001).

CONCLUSIONS

ASD surgery was associated with significantly greater SIMS than many other major operations, even when controlling for important perioperative factors. These data have implications for patient counseling, resource allocation, and informed consent.

Outcomes in Patients With Severe Chronic Lung Disease Undergoing Index Cardiac Operations

BACKGROUND

This study evaluated the impact of severe chronic lung disease on outcomes of index adult cardiac operations.

METHODS

A single-center, retrospective study of adult patients with severe chronic lung disease (as defined by The Society of Thoracic Surgeons) undergoing index cardiac operations between 2010 and 2018 was performed. Multivariable Cox regression and Kaplan-Meier analyses were used to evaluate survival.

RESULTS

Three hundred fifty-four patients (median age, 69 years; 32.77% women) were identified. Current smokers comprised 42.66% of the population, and 34.65% of patients required home oxygen. Median preoperative forced expiratory volume in 1 second was 48% of predicted (interquartile range, 41%-56%), and median diffusing capacity of the lungs for carbon monoxide was 78% of predicted (interquartile range, 55%-101%). Most patients underwent isolated coronary artery bypass (57.06%) or isolated aortic valve replacement (19.49%). Overall, 33 patients (9.07%) required a tracheostomy (median of 10 days from surgery) for a median of 49 days (interquartile range, 25-114) until decannulation. Preoperative home oxygen use was an independent predictor of 30-day (hazard ratio, 2.91; P = .030) and 1-year (hazard ratio, 2.12; P = .009) mortality. One-year and 5-year postoperative survival were 83.62% and 58.34%, respectively.

CONCLUSIONS

Although severe chronic lung disease is a predictor of mortality and morbidity after index cardiac operations, only 9% of patients required a tracheostomy, and most were alive at 5 years after surgery. Home oxygen use may serve as a further stratification tool in this higher risk subset; however the presence of severe chronic lung disease alone should not deter from surgery in otherwise reasonable surgical candidates.

Frequency of Blood Transfusion in Elective Coronary Artery Bypass Grafting and Its Correlation With Acute Kidney Injury at a Tertiary Care Hospital in a Lower Middle-Income Country

Background

Blood transfusion remains a significant management aspect in various cardiac surgical procedures including coronary artery bypass grafting (CABG). These patients have a reportedly high incidence of transfusion of blood products. It varies considerably amongst different institutions; most variability being seen in the transfusion trigger. This case series enumerate the frequency of administration of blood products in patients during elective CABG and its association with acute kidney injury (AKI) and ascertain whether blood transfusion is justifiable at a tertiary care hospital.

Materials and methods

Using non-probability consecutive sampling, 172 patients were enrolled in the study. Patient’s preoperative hemoglobin and creatinine, intraoperative hemoglobin, transfusion trigger, number of transfusions (whole blood and packed RBCs-PRBCs), postoperative hemoglobin and creatinine in the ICU and number of transfusions in the first 24 hours were recorded.

Results

Out of the 172 patients, 96 (55.81%) patients received blood transfusion and 73 (42.69%) patients suffered from AKI. 45 (61.64%) patients with AKI received transfusion whereas 28 (38.36%) patients had no transfusion. Of these 96 patients, 45 (46.8%) received transfusion intra-operatively, 24 (25%) patients received both intra-operatively and post-operatively while 27 (28.2%) patients were transfused postoperatively. Majority of the patients, 46 (88.3%), received unjustifiable transfusion (Hb >8 g/dl) during the first 24 hours post-operatively.

Conclusion

There is marked divergence in the peri-operative use of blood products that remain on a loco-regional as well as international basis. A standardized and a multidisciplinary strategy as well as robust institutional regulation would significantly reduce inappropriate patient exposure to blood products.

Association between smoking and in-hospital mortality in patients with left ventricular dysfunction undergoing coronary artery bypass surgery: a propensity-matched study

Background

Data on the effect of smoking on In-hospital outcome in patients with left ventricular dysfunction undergoing coronary artery bypass graft (CABG) surgery are limited. We sought to determine the influence of smoking on CABG patients with left ventricular dysfunction.

Methods

A retrospective study was conducted using data from the China Heart Failure Surgery Registry database. Eligible patients with left ventricular ejection fraction less than 50% underwent isolated CABGS were included. In addition to the use of multivariate regression models, a 1–1 propensity scores matched analysis was performed. Our study (n = 6531) consisted of 3635 smokers and 2896 non-smokers. Smokers were further divided into ex-smokers (n = 2373) and current smokers (n = 1262).

Results

The overall in-hospital morality was 3.9%. Interestingly, current smokers have lower in-hospital mortality than non-smokers [2.3% vs 4.9%; adjusted odds ratio (OR) 0.612 (95% CI 0.395–0.947) ]. No difference was detected in mortality between ex-smokers and non-smokers [3.6% vs 4.9%; adjusted OR 0.974 (0.715–1.327)]. No significant differences in other clinical end points were observed. Results of propensity-matched analyses were broadly consistent.

Conclusions

It is paradoxically that current smokers had lower in-hospital mortality than non-smokers. Future studies should be performed to further understand the biological mechanisms that may explain this ‘smoker’s paradox’ phenomenon.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02056-9.

Smoking behavior after coronary artery bypass surgery: Quit, relapse, continuing

Objective:

Tobacco smoking represents a major risk factor for coronary artery disease. Our study aimed to investigate whether Coronary Artery Bypass Graft (CABG) surgery could act as a motivating factor to enforce smoking cessation. Specifically, we observed the success rate in individuals who quitted smoking, along with the number and reasons of relapse(s) at least one year after the operation.

Methods:

The pre-operative characteristics, pre-operative tobacco exposure, socioeconomic factors and perioperative complications in patients who underwent isolated Coronary Artery Bypass Graft surgery in our Department from June 2012 to September 2016 were reviewed. Our survey was conducted via phone interview and using a standardized questionnaire. Only patients who were current smokers at the time of surgery were interviewed.

Results:

Our study group consisted of a total of 120 patients, 91 (75.8%) reported initially quitting tobacco smoking. Because of relapse(s), one year after the procedure the number of patients who were still non-smokers dropped to 69 (57.5%). Smoking cessation attempts were not supported by professional assistance.

Conclusions:

Our findings demonstrate that there is a desire from CABG patients to quit smoking, as indicated by the high percentage of initial attempts in early postoperative period. However, a year after the procedure, only 57.5% of CABG patients were able to achieve or maintain smoking cessation. Patients who were retired or who were unemployed at the time of the surgery, found it easier to stop smoking than patients who were active employees. Patients who lived alone at the time of surgery also found it harder to stop smoking. Finally, patients with COPD also found quitting smoking harder in the post-operative period.

Impact of smoking on all-cause mortality and cardiovascular events in patients after coronary revascularization with a percutaneous coronary intervention or coronary artery bypass graft: a systematic review and meta-analysis

Although cigarette smoking is an independent risk factor for cardiovascular disease, inconsistent results have been published in the literature on its impacts on the cardiovascular health of patients after coronary revascularization with a percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG). We performed a comprehensive electronic database search through July 2018. Studies reporting the risk estimates of all-cause mortality and cardiovascular outcomes in patients after coronary revascularization with PCI or CABG on the basis of smoking status were selected. Multivariate-adjusted relative risks (RRs) and 95% confidence intervals (CIs) were pooled using random-effects models with inverse variance weighting. Data from 37 records including 126 901 participants were finally collected. Overall, the pooled RR (95% CI) associated with cigarette smoking was 1.26 (95% CI: 1.09-1.47) for all-cause mortality, 1.08 (95% CI: 0.92-1.28) for major adverse cardiovascular events, 0.96 (95% CI: 0.69-1.35) for cardiovascular mortality and 1.15 (95% CI: 0.81-1.64) for myocardial infarction. The increased risk of all-cause mortality was also observed in former smokers compared with those who had never smoked (RR: 1.19; 95% CI: 1.03-1.38). Furthermore, the negative effects of cigarette smoking on all-cause mortality were also observed in most subgroups. Cigarette smoking has been shown to increase the likelihood of all-cause mortality in patients after coronary revascularization with PCI or CABG. Smoking cessation is essential for PCI or CABG patients to manage their coronary artery disease.

Smoking Cessation After Surgery and Midterm Outcomes of Surgical Revascularization

BACKGROUND

Although multiple studies have reported the devastating effect of cigarette smoking (CS) on short-term outcomes of patients who underwent coronary artery bypass grafting surgery (CABG), its effect on long-term outcomes is still questionable. We aimed to evaluate the long-term outcomes of CS cessation after CABG surgery.

METHODS

This retrospective cohort study included all patients who underwent isolated CABG at our center between 2007 and 2016 and were cigarette smokers either just before or at the time of surgery. Patients were stratified into those who continued CS and those who were persistently CS abstinent after CABG. The endpoints of the study were 5-year mortality and 5-year major adverse cardiovascular and cerebrovascular events.

RESULTS

Of 28,945 patients who underwent isolated CABG, 9173 current cigarette smokers (93.5% men; mean age, 58.6 years) met our selection criteria and were included in the final analysis. Of these 3302 patients (40.0%) continued CS after surgery and 5688 patients were persistently abstinent. Multivariable survival analysis demonstrated that CS cessation after CABG, adjusted for major coronary risk factors, could reduce the 5-year mortality by 35% (hazard ratio, 0.65; 95% confidence interval, 0.54-0.77; P < .001) and 5-year major adverse cardiovascular and cerebrovascular events by 18% (hazard ratio, 0.82; 95% confidence interval, 0.74-0.92; P = .001).

CONCLUSIONS

Our study shows that CS abstinence after CABG significantly reduces long-term mortality and number of major adverse events. As a result, patients who smoke should be encouraged to participate in CS cessation programs after CABG surgery.

Smoking cessation affects human platelet activation induced by collagen

It is firmly established that smoking is a risk factor of cardiovascular disease, stroke and peripheral vascular disease. Although smoking alters the hemostatic process, the influence of smoking on human platelet activation remains controversial. For patients undergoing surgery, cessation of smoking prior to the procedure is recommended as it increases the risk of postoperative morbidity or mortality. The presented study investigated the effects of smoking cessation on human platelet activation induced via collagen (n=19 patients). Blood samples were taken on four occasions: Before smoking cessation, and at 4, 8 and 12 weeks after smoking cessation. Platelet aggregation using citrated platelet-rich plasma (PRP) was monitored using a PA-200 aggregometer, which determined the size of platelet aggregates using laser scattering methods. A low dose of collagen (1 µg/ml) accelerated platelet aggregation at 4 or 8 weeks after smoking cessation when compared with results before cessation. After 12 weeks, levels of platelet aggregation induced by collagen were almost equal to those recorded prior to smoking cessation. The secretion levels of collagen-induced platelet-derived growth factor (PDGF)-AB at 4 or 8 weeks after smoking cessation were significantly higher than those before smoking was stopped. Furthermore, smoking cessation markedly strengthened the collagen-induced phosphorylation of p38 mitogen-activated protein (MAP) kinase after 4 weeks. The results of the current study indicated that smoking cessation causes temporary short-term human platelet hyper-activation. The further suggest that the incidence of complications due to human platelet hyper-reactivity may be lowered by considering the period of smoking abstinence.

Effect of Opium Addiction on Postoperative Arrhythmia Among Patients Undergoing CABG operation on Cardiopulmonary Bypass

OBJECTIVES

Postoperative arrhythmia is an important complication of coronary artery bypass grafting (CABG) surgeries among patients. It seems that opioid usage is implicated in the pathogenesis of this condition due to its impacts on different organ systems, such as the autonomic nervous system. The present study was performed to investigate the effect of opium use on postoperative arrhythmia in patients undergoing CABG surgery.

METHODS

Study participants were selected via convenience sampling from patients undergoing CABG surgery in a referral hospital. Study variables, including use of inotropic drugs, vital signs monitoring parameters and postoperative arrhythmia were observed and recorded at baseline and at follow-up time after surgery.

RESULTS

Sixty-five (14.8%) patients had postoperative arrhythmia, and 104 participants were addicted. Prevalence of postoperative arrhythmia was the same among addict and non-addict patients. According to the regression analysis model, only serum level of epinephrine in operating room, heart rate and central venous pressure at baseline and 48 hours after operation are known as independent predictors of postoperative arrhythmia among study population.

CONCLUSION

This study showed that although opium addiction increased postoperative arrhythmia among patients undergoing CABG surgery, this difference was not significant, and this association is probably mediated by other study variables.

Procedure- and Hospital-Level Variation of Deep Sternal Wound Infection From All-Japan Registry

BACKGROUND

The outcome of cardiovascular surgery has been improving over time, but the treatment of postoperative complications such as deep sternal wound infection (DSWI) still needs critical attention. A nationwide surgical registry was analyzed for procedural details and hospital factors related to DSWI.

METHODS

The study used the Japan Adult Cardiovascular Surgery Database, which captured data from 82% of all the hospitals performing cardiac surgery in Japan. A total of 109,717 surgical cases (34,980 coronary artery bypass grafting, 43,602 valve operations, 31,135 thoracic aortic operations) were included in the study.

RESULTS

The overall incidence of DSWI was 1738 (1.6%). The 30-day mortality and operative mortality were 3311 (3.0%) and 5155 (4.7%), respectively. Across the 3 procedures, thoracic aortic operation showed the highest odds ratio (2.61; 95% confidence interval [CI], 2.32 to 2.94) for operative mortality but the lowest (0.91; 95% CI:,0.73 to 1.13) for DSWI incidence. Conversely, coronary artery bypass grafting showed the lowest odds ratio (1.36; 95% CI, 1.24 to 1.49) for operative mortality but the highest (1.52; 95% CI, 1.32 to 1.76) for DSWI. There was also hospital-level variation: Correlation was statistically significant between the observed-to-expected ratio of DSWI incidence and the observed-to-expected mortality ratio of cardiovascular procedures across the hospitals, but the coefficient was small (r = .24, P < .001).

CONCLUSIONS

Hospitals that have a lower risk-adjusted mortality rate of cardiovascular procedures do not always have a lower risk-adjusted DSWI occurrence rate. In addition, the incidence of DSWI varies across hospitals. We need to consider DSWI independently of surgical mortality, whereas for treatment we should consider both the specific hospital environment and the multidisciplinary care.

Preoperative cigarette smoking and short-term morbidity and mortality after cardiac surgery: a meta-analysis

Currently, the choice of whether or not to electively operate on current smokers is varied among cardiothoracic surgeons. This meta-analysis aims to determine whether preoperative current versus ex-smoking status is related to short-term postoperative morbidity and mortality in cardiac surgical patients. Systematic literature searches of the PubMed, MEDLINE and Cochrane databases were carried out to identify all studies in cardiac surgery that investigated the relationship between smoking status and postoperative outcomes. Extracted data were analysed by random effects models. Primary outcomes included 30-day or in-hospital all-cause mortality and pulmonary morbidity. Overall, 13 relevant studies were identified, with 34 230 patients in current or ex-smoking subgroups. There was no difference in mortality (p=0.93). Current smokers had significantly higher risk of overall pulmonary complications (OR 1.44; 95% CI 1.27 to 1.64; p<0.001) and postoperative pneumonia (OR 1.62; 95%  CI 1.27 to 2.06; p<0.001) as well as lower risk of postoperative renal complications (OR 0.82; 95%  CI 0.70 to 0.96; p=0.01) compared with ex-smokers. There was a trend towards an increased risk of postoperative MI (OR 1.29; 95%  CI 0.95 to 1.75; p=0.10). No difference in postoperative neurological complications (p=0.15), postoperative sternal surgical site infections (p=0.20) or postoperative length of intensive care unit stay (p=0.86) was seen. Cardiac surgical patients who are current smokers at the time of operation do not have an increased 30-day mortality risk compared with ex-smokers, although they are at significantly increased risk of postoperative pulmonary complications.

Factors influencing transfusion requirement in patients undergoing first-time, elective coronary artery bypass graft surgery

CONTEXT

Coronary artery bypass graft (CABG) operation is associated with high frequency of allogeneic blood transfusion due to the acquired hemostatic challenges in patients undergoing CABG. However, allogeneic blood transfusion carries risks of infection, adverse reaction, and mortality as well as prolonged hospital stay and increased hospital cost. It is important to identify patients who require blood transfusion to mitigate their risk factors and reduce the chance of exposure to allogeneic blood.

AIMS

This study was conducted to evaluate factors that influence the decision to transfuse red cell in first-time elective CABG patients.

SETTINGS AND DESIGN

This was a cross-sectional study based on a retrospective record review. The study was done in the National Heart Institute.

MATERIALS AND METHODS

All patients who underwent first-time elective CABG were included in this study. Variables analyzed include age, gender, body weight, preoperative hemoglobin (Hb) level, patients' comorbidities, and other clinical parameters.

STATISTICAL ANALYSIS USED

Data were analyzed using SPSS software version 20.

RESULTS

A total of 463 patients underwent first-time elective CABG during the period of the study. Three hundred and eighty-six (83.4%) patients received red cell transfusion. From multiple logistic regression analysis, only age (odds ratio [OR] = 1.040, 95% confidence interval [CI]: 1.003, 1.077, P = 0.032), body weight (OR = 0.951, 95% CI: 0.928, 0.974, P < 0.001), Hb level (OR = 0.500, 95% CI: 0.387, 0.644, P < 0.001), and cardiopulmonary bypass time (OR = 1.013, 95% CI: 1.004, 1.023, P < 0.001) were the significant independent predictors of red cell transfusion.

CONCLUSIONS

By stratifying patients according to their risk factor for red cell transfusion, the high-risk patients could be recognized and should be enrolled into effective patient blood management program to minimize their risk of exposure to allogeneic blood transfusion.

Acute respiratory distress syndrome after cardiac surgery

Acute respiratory distress syndrome (ARDS) is a leading cause of postoperative respiratory failure, with a mortality rate approaching 40% in the general population and 80% in the subset of patients undergoing cardiac surgery. The increased risk of ARDS in these patients has traditionally been associated with the use of cardiopulmonary bypass (CPB), the need for blood product transfusions, large volume shifts, mechanical ventilation and direct surgical insult. Indeed, the impact of ARDS in the cardiac population is substantial, affecting not only survival but also in-hospital length of stay and long-term physical and psychological morbidity. No patient undergoing cardiac surgery can be considered ARDS risk-free. Early identification of those at higher risk is crucial to warrant the adoption of both surgical and non-surgical specific preventative strategies. The present review focuses on epidemiology, risk assessment, pathophysiology, prevention and management of ARDS in the specific setting of patients undergoing cardiac surgery.

A Preoperative Risk Model for Postoperative Pneumonia After Coronary Artery Bypass Grafting

BACKGROUND

Postoperative pneumonia is the most prevalent of all hospital-acquired infections after isolated coronary artery bypass graft surgery (CABG). Accurate prediction of a patient's risk of this morbid complication is hindered by its low relative incidence. In an effort to support clinical decision making and quality improvement, we developed a preoperative prediction model for postoperative pneumonia after CABG.

METHODS

We undertook an observational study of 16,084 patients undergoing CABG between the third quarter of 2011 and the second quarter of 2014 across 33 institutions participating in the Michigan Society of Thoracic and Cardiovascular Surgeons Quality Collaborative. Variables related to patient demographics, medical history, admission status, comorbid disease, cardiac anatomy, and the institution performing the procedure were investigated. Logistic regression through forward stepwise selection (p < 0.05 threshold) was utilized to develop a risk prediction model for estimating the occurrence of pneumonia. Traditional methods were used to assess the model's performance.

RESULTS

Postoperative pneumonia occurred in 3.30% of patients. Multivariable analysis identified 17 preoperative factors, including demographics, laboratory values, comorbid disease, pulmonary and cardiac function, and operative status. The final model significantly predicted the occurrence of pneumonia, and performed well (C-statistic: 0.74). These findings were confirmed through sensitivity analyses by center and clinically important subgroups.

CONCLUSIONS

We identified 17 readily obtainable preoperative variables associated with postoperative pneumonia. This model may be used to provide individualized risk estimation and to identify opportunities to reduce a patient's preoperative risk of pneumonia through prehabilitation.

Prolonged postoperative respiratory support after proximal thoracic aortic surgery: Is deep hypothermic circulatory arrest a risk factor?

PURPOSE

In addition to the pulmonary risks associated with cardiopulmonary bypass, thoracic aortic surgery using deep hypothermic circulatory arrest (DHCA) may subject the lungs to further injury. However, this topic has received little investigation to date.

MATERIALS AND METHODS

A prospective cohort review was performed on all patients undergoing proximal thoracic aortic surgery with (n = 478) and without (n = 135) DHCA between July 2005 and February 2013 at a single institution. The primary outcome was prolonged postoperative respiratory support (PPRS), defined as any of the following: >1 day of mechanical ventilation at either fraction of inspired oxygen >0.4 and/or positive end-expiratory pressure >5 mm Hg, >2 days of supplemental O2 requirement of at least 2.5 L/min, or discharge with new O2 requirement. Independent risk factors for PPRS were identified using multivariable logistic regression.

RESULTS

Postoperative respiratory support was required in 100 patients (20.9%) with and 30 patients (22.2%) without DHCA (P = .74). Independent predictors of PPRS after proximal aortic surgery included the following: age, diabetes, history of stroke, preoperative creatinine, American Society of Anesthesiologists class 4, redo-sternotomy, total arch replacement, and transfusion requirement. Use of DHCA was not an independent risk factor for PPRS in the entire cohort. Subanalysis of only DHCA patients revealed that longer DHCA times were independently associated with PPRS.

CONCLUSIONS

Prolonged postoperative respiratory support is common after proximal aortic surgery. The use of DHCA was not associated with this complication in the overall cohort, although longer DHCA times were predictive when only the subset of patients undergoing DHCA was analyzed. Knowledge of the risk factors for PPRS after proximal aortic surgery should improve preoperative risk stratification and postoperative management of these patients.

The effects of discharge training and counseling on post-discharge problems in patients undergoing coronary artery bypass graft surgery

Background:

Advances in coronary artery surgery have reduced morbidity, mortality, and rates of graft occlusion. Discharge programs are important services for the continuity of treatment and must encompass physical, psychological, and social aspects of individual patient care. This study aimed at investigating the effect of planned discharge training and counseling on the problems experienced by patients undergoing coronary artery bypass graft (CABG) surgery.

Materials and Methods:

A semi-experimental study was performed on 100 patients undergoing CABG surgery in the surgery department. During a period of 9 months from January to September 2013, the patients in the intervention group were provided with adequate discharge training and counseling with a booklet before surgery and counseling until 6 weeks after discharge, while the control group patients received only routine clinical procedures, i.e. prescribing medicine, controlling vital signs, and wound dressing. The data were analyzed using Statistical Package for the Social Sciences (SPSS) 23. Frequency and distribution were used to describe the data, and paired sample t-test, variance analysis, Fisher's exact test, and Chi-squared tests were also used.

Results:

The reported problems for both groups had a descending pattern during the three follow-ups. However, this pattern had a greater slope in the intervention group compared to the control one. As a result of these education programs, problems were fewer in the intervention group than in the control group (P < 0.05).

Conclusions:

Discharge training and counseling given to the intervention group had a positive impact on decreasing the problems that the patients had. Therefore, the institutions may be recommended to support multidisciplinary patient training and counseling activities using the methods described in this study.

Impact of smoking on early clinical outcomes in patients undergoing coronary artery bypass grafting surgery

Background

To evaluate the impact of persistent smoking versus smoking cessation over one month prior to surgery on early clinical outcomes in Chinese patients undergoing isolated coronary artery bypass grafting (CABG) surgery in a retrospective study.

Methods

The peri-operative data of consecutive well-documented patients undergoing isolated CABG surgery from January 2007 to December 2013 were investigated and retrospectively analyzed. All included patients were divided into either a non-smoking group or a smoking group according to preoperative smoking records. Furthermore, smokers were divided into either a former smoking subgroup (smokers with smoking cessation over 1 month before surgery) or a current smoking subgroup (persistent smokers).

Results

A total of 3730 consecutive patients (3207 male patients and mean 63.6 ± 9.5 years) undergoing isolated CABG surgery were analyzed. Persistent smokers had significantly higher incidence of postoperative pulmonary complications as compared to non-smokers (7.8% vs. 4.5%, p = 0.0002). No significantly differences in both surgical mortality and major postoperative morbidities between smokers with smoking cessation over 1 month before surgery and non-smokers were found. In multiple logistic regression analysis, the risk of postoperative pulmonary complications in persistent smokers was 2.41 times than that in non-smokers, whereas the risk of postoperative pulmonary complications in smokers with smoking cessation over 1 month before surgery was similar to non-smokers.

Conclusions

Persistent smokers had a higher incidence of pulmonary complications following CABG as compared to non-smokers. Smoking cessation more than 1 month before surgery was expected to reduce early major morbidities following CABG surgery.

Center-level variation in infection rates after coronary artery bypass grafting

BACKGROUND

Health-care-acquired infections (HAIs) are a leading cause of morbidity and mortality after cardiac surgery. Prior work has identified several patient-related risk factors associated with HAIs. We hypothesized that rates of HAIs would differ across institutions, in part attributed to differences in case mix.

METHODS AND RESULTS

We analyzed 20 896 patients undergoing isolated coronary artery bypass grafting surgery at 33 medical centers in Michigan between January 1, 2009, and June 30, 2012. Overall HAIs included pneumonia, sepsis/septicemia, and surgical site infections, including deep sternal wound, thoracotomy, and harvest/cannulation site infections. We excluded patients presenting with endocarditis. Predicted rates of HAIs were estimated using multivariable logistic regression. Overall rate of HAI was 5.1% (1071 of 20 896; isolated pneumonia, 3.1% [n=644]; isolated sepsis/septicemia, 0.5% [n=99]; isolated deep sternal wound infection, 0.5% [n=96]; isolated harvest/cannulation site, 0.5% [n=97]; isolated thoracotomy, 0.02% [n=5]; multiple infections, 0.6% [n=130]). HAI subtypes differed across strata of center-level HAI rates. Although predicted risk of HAI differed in absolute terms by 2.8% across centers (3.9-6.7%; min:max), observed rates varied by 18.2% (0.9-19.1%).

CONCLUSIONS

There was a 18.2% difference in observed HAI rates across medical centers among patients undergoing isolated coronary artery bypass grafting surgery. This variability could not be explained by patient case mix. Future work should focus on the impact of other factors (eg, organizational and systems of clinical care) on risk of HAIs.

Long-term survival of non-smokers undergoing coronary artery bypass surgery

OBJECTIVES

We sought to investigate long-term survival of non-smokers undergoing coronary artery bypass surgery (CABG).

METHODS

A prospective database of consecutive patients was retrospectively analysed and cross correlated with the UK strategic tracking service to evaluate survival after primary CABG. Univariate, multivariate and a propensity analyses were performed.

RESULTS

We analysed 13 337 primary CABG procedures. Median follow-up was 7 years. Kaplan-Meier survival curves demonstrate that non-smokers have a significantly improved long-term survival compared with ex- and current smokers, P < 0.0001. Cox regression analysis identified smoking status, age, diabetes, ejection fraction (EF), body mass index, cerebrovascular disease, dialysis, left internal mammary artery (LIMA) non-usage, postoperative creatinine kinase muscle-brain isoenzyme (CKMB), radial artery usage, preoperative rhythm, forced vital capacity (FVC) and logistic EuroSCORE as significant risk factors determining long-term survival. Propensity matching resulted in 3575 non-smokers being matched 1:1, with ex-smokers. After matching, univariate analysis demonstrated the significantly worse long-term survival of ex-smokers compared with non-smokers, P < 0.0001. Cox regression analysis identified smoking status, age, postoperative CKMB, cerebrovascular disease, dialysis, diabetes, EF, FVC, LIMA non-usage, radial artery used, sinus rhythm and logistic EuroSCORE as significant risk factors determining long-term survival. Survival by smoking status plotted at the mean of the covariates, prepropensity matching, demonstrated that non-smokers had a significantly better long-term survival than ex-smokers, P < 0.0001; however, after propensity matching, non-smokers under 65 years of age had a significantly worse long-term survival compared with ex-smokers, P < 0.0001.

CONCLUSIONS

Non-smokers under the age of 65 years of age have significantly worse long-term survival compared with ex-smokers after risk factor adjustment. We speculate that this is because ex-smokers have had the causative factor, smoking, removed, but non-smokers have not.

Is there benefit in smoking cessation prior to cardiac surgery?

A best evidence topic was written according to a structured protocol. The question addressed was whether smoking cessation prior to cardiac surgery would result in a greater freedom from postoperative complications. A total of 564 papers were found using the reported searches, of which five represented the best evidence to answer the clinical question. The authors, date, journal, study type, population, main outcome measures and results are tabulated. Reported measures were operative mortality, pulmonary complications, infective complications, neurological complications, transfusion requirements, duration of ventilation, intensive care unit and hospital stay, intensive care unit re-admission, postoperative gas exchange parameters and postoperative pulmonary function. The largest of the best evidence studies demonstrated a significant reduction in pulmonary complications in non-smokers (P < 0.001); however, there was an increased requirement for transfusion in this cohort (P = 0.002). There were non-significant reductions in neurological complications, infective complications and re-admissions to intensive care. Another large cohort study demonstrated significant reductions in non-smokers in mortality (P < 0.0001), pulmonary complications (P = 0.0002), infection (P < 0.0007), intensive care unit re-admission (P = 0.0002), duration of mechanical ventilation (P = 0.026) and intensive care unit stay (P = 0.002). A larger cohort study again demonstrated significant reductions in non-smokers in pulmonary complications (P < 0.002), duration of mechanical ventilation (P < 0.012) and intensive care unit stay (P < 0.005). A smaller prospective cohort study reported significantly raised PaO(2) (P = 0.0091) and reduced PaCO(2) (P < 0.0001) levels in the non-smokers as well as improved FVC and FEV(1) (P < 0.0001). There were also reductions in duration of intubation (P < 0.0001), intensive care unit stay (P < 0.0001) and hospital stay (P < 0.0013). Another small cohort study reporting outcomes of heart transplantation demonstrated significant improvement in non-smokers in terms of survival (P = 0.031), duration of intubation (P = 0.05) and intensive care unit stay (P = 0.021). We conclude that there is strong evidence demonstrating superior outcomes in non-smokers following cardiac surgery and advocate the necessity of smoking cessation as soon as possible prior to cardiac surgery.

Short-term preoperative smoking cessation and postoperative complications: a systematic review and meta-analysis

PURPOSE

The literature was reviewed to determine the risks or benefits of short-term (less than four weeks) smoking cessation on postoperative complications and to derive the minimum duration of preoperative abstinence from smoking required to reduce such complications in adult surgical patients.

SOURCE

We searched MEDLINE, EMBASE, Cochrane, and other relevant databases for cohort studies and randomized controlled trials that reported postoperative complications (i.e., respiratory, cardiovascular, wound-healing) and mortality in patients who quit smoking within six months of surgery. Using a random effects model, meta-analyses were conducted to compare the relative risks of complications in ex-smokers with varying intervals of smoking cessation vs the risks in current smokers.

PRINCIPAL FINDINGS

We included 25 studies. Compared with current smokers, the risk of respiratory complications was similar in smokers who quit less than two or two to four weeks before surgery (risk ratio [RR] 1.20; 95% confidence interval [CI] 0.96 to 1.50 vs RR 1.14; CI 0.90 to 1.45, respectively). Smokers who quit more than four and more than eight weeks before surgery had lower risks of respiratory complications than current smokers (RR 0.77; 95% CI 0.61 to 0.96 and RR 0.53; 95% CI 0.37 to 0.76, respectively). For wound-healing complications, the risk was less in smokers who quit more than three to four weeks before surgery than in current smokers (RR 0.69; 95% CI 0.56 to 0.84). Few studies reported cardiovascular complications and there were few deaths.

CONCLUSION

At least four weeks of abstinence from smoking reduces respiratory complications, and abstinence of at least three to four weeks reduces wound-healing complications. Short-term (less than four weeks) smoking cessation does not appear to increase or reduce the risk of postoperative respiratory complications.

Short-term outcome of solitary kidney patients undergoing on-pump cardiac surgery

OBJECTIVE

The outcome of patients with solitary kidney undergoing on-pump cardiac surgery is unknown. We sought to assess the in-hospital mortality and complications in these patients compared with patients with normal renal function.

METHODS

This is a retrospective review of prospectively collected data over an 8-year period of all patients who underwent cardiac surgery. Our cohort consisted of 3363 consecutive patients divided into: solitary kidney (n=31, 0.9%) and normal kidneys (n=3332, 99.1%). Postoperative complications and in-hospital mortality were analysed.

RESULTS

Solitary kidney patients had higher incidence of renal failure (26% vs 5%, p-value<0.001), higher incidence of gastrointestinal complications (10% vs 1%, p-value 0.009) and higher blood transfusions (74% vs 43%, p-value<0.001) compared with patients with normal kidneys. There was an increased length of both intensive care unit stay (3.8 vs 2.2 days, p-value 0.031) and hospital stay (15.6 vs 8.5 days, p-value 0.026) among patients with solitary kidney compared with normal kidney patients. Multivariate analysis showed that solitary kidney is an independent predictor of postoperative renal failure (odds ratio (OR) 7.1 (95%CI 3.1-16.6)), gastrointestinal complications (OR 8.5 (95%CI 2.5-29.4)) and blood transfusion (OR 3.8 (95%CI 1.6-9.0)) after adjusting for age and gender. In-hospital mortality, however, was similar in both groups.

CONCLUSION

Although solitary kidney patients have similar short-term mortality as normal kidney patients, the rates of postoperative renal failure, gastrointestinal complications and blood transfusion are significantly higher among solitary kidney patients. Our findings have important clinical implications and prior knowledge of such entity with appropriate risk stratification at admission could help in reducing the risk of these potential complications.

Cross-clamp time is an independent predictor of mortality and morbidity in low- and high-risk cardiac patients

OBJECTIVES

We sought to assess the effects of aortic cross-clamp time (XCL) on outcome following cardiac surgery in low- and high-risk patients.

METHODS

This is a retrospective review of prospectively collected departmental data of all patients who underwent cardiac surgery over 8-year period. Our cohort consisted of 3799 consecutive patients subdivided into low-risk (Euro SCORE < 6, n = 2691, 71%) and high-risk (Euro SCORE ≥ 6, n = 1108, 29%). Each class was further stratified into three groups based on their corresponding XCL time. Group 1 (XCL ≤ 60 min), group 2 (XCL > 60 but ≤ 90 min) and group 3 (XCL >90 min). Postoperative morbidity and in-hospital mortality were analysed.

RESULTS

Univariate analysis showed the following to be significantly associated with increased XCL time in both low- and high-risk patients: low cardiac output, prolonged ventilation time, renal complications, prolonged hospital stay, blood transfusion and increased mortality (p < 0.05). By using multiple logistic regression, aortic XCL time >60 min was independent risk factor for low cardiac output, prolonged ventilation, renal complication, blood transfusion, mortality and prolonged hospital stay in both groups. By using XCL time as a continuous variable, an incremental increase of 1 min interval in XCL time was associated with a 2% increase in mortality in both groups.

CONCLUSION

Prolonged cross-clamp time significantly correlates with major post-operative morbidity and mortality in both low- and high-risk patients. This effect increases with increasing XCL time. Prior knowledge on this effect can help in preventing some of these complications.