Uncomplicated Coronary Artery Bypass Grafting Research Articles

Safety of Early Discharge After Coronary Artery Bypass Grafting: A Nationwide Readmissions Analysis

BackgroundWe determined the safety of early discharge after coronary artery bypass grafting (CABG) in patients with uncomplicated postoperative courses and compared outcomes with routine discharge in a national cohort. We identified preoperative factors associated with readmission after early discharge after CABG. MethodsThe Nationwide Readmissions Database was queried to identify patients undergoing CABG from January 2016 to December 2018. Patients were stratified based on length of stay (LOS) as early (≤4 days) vs routine (5-10 days) discharge. Patients were excluded with hospital courses indicative of complicated stays (emergent procedures, LOS >10 days, discharge to extended care facility or with home health, index hospitalization mortality). Propensity score matching was performed to compare outcomes between cohorts. Multivariable logistic regression models were used to identify factors associated with readmission after early discharge. ResultsDuring the study period, 91,861 patients underwent CABG with an uncomplicated postoperative course (∼20% of CABG population). Of these, 31% (28,790 of 91,861) were discharged early, and 69% (63,071 of 91,861) were routinely discharged. After propensity score matching, patients discharged early had lower readmission rates at 30 days, 90 days, and up to 1 year (P < .001 for all). The index hospitalization cost was lower with early discharge ($26,676 vs $32,859; P < .001). Early discharge was associated with a lower incidence of nosocomial infection at the index hospitalization (0.17% vs 0.81%, P < .001) and readmission from infection (14.5% vs 18%, P = .016). ConclusionsEarly discharge after uncomplicated CABG can be considered in a highly selective patient population. Early-discharge patients are readmitted less frequently than matched routine-discharge patients, with a lower incidence of readmission from infection. Appropriate postdischarge processes to facilitate early discharge after CABG should be further pursued.

Cost of a routine (planned) cardiac by-pass surgery at the National Hospital of Sri Lanka

Background: Non-communicable disease (NCD) has become a major challenge in Sri Lanka. Over the last 40 years, ischemic heart disease (IHD) has been identified as one of the leading causes of NCD deaths in Sri Lanka. Coronary artery bypass graft (CABG) is a revascularization procedure that has been identified as an effective method for managing a patient with IHD. Therefore, estimating the approximate cost of CABG surgery in a public hospital would help in economic evaluations and managerial decision-making in public sector investments.Objective: To estimate the approximate cost of an uncomplicated routine (planned) cardiac bypass surgery at the National Hospital of Sri Lanka (NHSL), Colombo.Methods: This study was primarily based on secondary data. The data required for costing the procedure was extracted from 52 BHTs of patients who underwent CABG surgery at the NHSL during the last three months of the year 2019. Extracted data was used to determine the costing elements of each cost center. Direct and indirect cost centers were identified, and the cost of each center was determined by apportioning the available cost data by the step-down method using a weighted factor where applicable.Results: The approximate cost of an uncomplicated CABG was Rs. 1.3 million per patient. Out of the total cost, 89% (Rs. 1.16 million) was expended on direct labor as salaries of different categories of staff. A major portion of it (56%) was spent on ICU care (Rs. 0.654 million) followed by post-surgical care at the ward settings (33.9%, Rs. 0.393 million). The highest cost of the material was recorded at the theatre which was 6% of the total cost (Rs. 78,960.00). The cost of total overheads was Rs. 29,517.00 which was about 2.2% of the total. Conclusion: Although the approximate cost of a routine uncomplicated CABG surgery was Rs.1.3 million ($ 7,027) as of December 2019 at the National Hospital of Sri Lanka, compared to more developed countries this is a fairly low cost. However, when the differences between health system organization and per capita health expenditure are concerned, this is quite evident to claim that the Sri Lankan health system has low-cost but effective models of delivering its care to people.

INTRAOPERATIVE NON-INVASIVE LEFT VENTRICULAR MYOCARDIAL WORK INDICES IN PATIENTS UNDERGOING ON-PUMP CORONARY ARTERY BYPASS SURGERY

<h3>Objective</h3> Non-invasive echocardiographic analysis of left ventricular (LV) myocardial work (MW) enables insights into cardiac mechanics, contractility, and efficacy beyond ejection fraction and global longitudinal strain. MW incorporates myocardial deformation and loading conditions into its analysis and correlates well with invasively measured myocardial work outside the operative setting. However, there are no reports on the use of this method by transesophageal echocardiography (TEE) in patients undergoing coronary artery bypass graft (CABG) surgery. Therefore, we aim to describe the intraoperative course of this novel assessment tool of ventricular function in these patients and compare it to conventional two- and three-dimensional echocardiographic parameters and strain analysis. <h3>Design and Method</h3> Twenty-five patients scheduled for isolated on-pump CABG surgery with preoperative preserved left and right ventricular function and a complication-free intraoperative course, were included into this prospective observational trial. TEE was performed intraoperatively after induction of anesthesia (T1), after termination of cardiopulmonary bypass (T2), and after sternal closure (T3) using General Electric Vivid E95 echocardiography machines and 6VT-D TEE probes. All measurements were performed under stable hemodynamic conditions, in sinus rhythm or atrial pacing and vasopressor support with Norepinephrine ≤ 0.1 µg/kg/min. EchoPAC v204 software (GE Vingmed Ultrasound AS, Norway) was used for analysis of 2D- and 3D LV ejection fraction (EF), LV global longitudinal strain (GLS), LV global work index (GWI), LV global constructive work (GCW), LV global wasted work (GWW) and LV global work efficiency (GWE). <h3>Results</h3> Myocardial work analysis was feasible in all patients. Although there was no significant difference in the values of 2D- and 3D-EF during the intraoperative interval, GLS deteriorated significantly after CABG compared to assessment after induction of anesthesia (T1 v T2, -13.3±3.0% v -11.6±3.1%; p=0.012). GWI declined significantly after surgery (T1 v T2, 1224±312mmHg% v 940±267mmHg%; p<0.001) as well as GCW (T1 v T2, 1460±312mmHg% v 1244±336 mmHg%; p=0.005). GWW increased after CABG (T1 v T2, 143mmHg% (IQR 99-183) v 251mmHg% (IQR 179-361); p<0.001) and GWE decreased (T1 v T2, 89% (IQR 85-92) v 80% (IQR 75-87); p<0.001). There was no significant change in the values of 2D- and 3D-EF, GLS, GWI, GCW, GWW and GWE before and after sternal closure (T2 v T3). <h3>Conclusions</h3> Intraoperative non-invasive echocardiographic assessed left ventricular myocardial work analysis appears feasible in this study. In our small sample with 25 CABG patients, strain and myocardial work analysis showed a deterioration of left ventricular function. In the short-term period after uncomplicated on-pump CABG, global and constructive myocardial work was decreased, while wasted work was increased, resulting in a less efficient left ventricle. None of these aspects was detected by two- and three-dimensional ejection fraction. Therefore, myocardial work analysis might be a more sensitive parameter in detecting myocardial dysfunction by TEE in the perioperative setting.

Intraoperative Noninvasive Left Ventricular Myocardial Work Indices in Patients Undergoing On-Pump Coronary Artery Bypass Surgery

Noninvasive echocardiographic analysis of left ventricular (LV) myocardial work (MW) enables insights into cardiac mechanics, contractility, and efficacy beyond ejection fraction (EF) and global longitudinal strain (GLS). However, there are limited perioperative data on patients undergoing coronary artery bypass graft (CABG) surgery. The authors aimed to describe the feasibility and the intraoperative course of this novel assessment tool of ventricular function in these patients, and compare it to conventional 2-dimensional (2D) and 3-dimensional (3D) echocardiographic parameters and strain analysis. A prospective observational study. At a single university hospital. Twenty-five patients with preoperative preserved LV and right ventricular function, sinus rhythm, without significant heart valve disease or pulmonary hypertension, and an uncomplicated intraoperative course scheduled for isolated on-pump CABG surgery. Transesophageal echocardiography (TEE) was performed intraoperatively after the induction of anesthesia (T1), after termination of cardiopulmonary bypass (T2), and after sternal closure (T3). All measurements were performed under stable hemodynamic conditions, in sinus rhythm or atrial pacing, and vasopressor support with norepinephrine ≤ 0.1 µg/kg/min. The EchoPAC v204 software (GE Vingmed Ultrasound AS, Norway) was used for analysis of 2D and 3D LVEF, LV GLS, LV global work index (GWI), LV global constructive work (GCW), LV global wasted work (GWW), and LV global work efficiency (GWE). The MW analysis was feasible in all patients. Although there was no significant difference in the values of 2D and 3D EF during the intraoperative interval, GLS deteriorated significantly after CABG compared to assessment after induction of anesthesia (T1 v T2, -13.3 ± 3.0% v -11.6 ± 3.1%; p=0.012). The GWI declined significantly after surgery (T1 v T2, 1,224 ± 312 mmHg% v 940 ± 267 mmHg%; p < 0.001), as well as GCW (T1 v T2, 1,460 ± 312 mmHg% v 1,244 ± 336 mmHg%; p=0.005). The GWW increased after CABG (T1 v T2, 143 mmHg% (IQR 99-183) v 251 mmHg% (IQR 179-361); p < 0.001), and GWE decreased (T1 v T2, 89% (IQR 85-92) v 80% (IQR 75-87); p < 0.001). There were no significant changes in the values of 2D and 3D EF, GLS, GWI, GCW, GWW, and GWE before and after sternal closure (T2 v T3). The intraoperative analysis of noninvasive echocardiographically-assessed LV MW indices is feasible. In the short-term period after uncomplicated on-pump CABG, GLS, as well as global and constructive MW, decreased, whereas wasted work increased, resulting in a less efficient left ventricle. None of these aspects was detected by conventional echocardiographic parameters. Therefore, strain and MW analysis might be more sensitive parameters in detecting myocardial dysfunction by TEE in the perioperative setting, adding information on perioperative cardiac energetics.

A Highly Unusual Cause of Right Anterior Proximal Clavicle Pain 5 Years After Uncomplicated Coronary Artery Bypass Surgery

A 52-YEAR-OLD, 123 kg, 188 cm man, with hypertension, hyperlipidemia, diabetes mellitus, and coronary artery disease, was referred back to the authors’ institution from the emergency department of another Veterans Affairs medical center for evaluation of sharp right chest pain adjacent to his proximal clavicle and superior manubrium of 2 weeks' duration. The patient had undergone uncomplicated coronary artery bypass graft surgery at the authors’ institution 5 years before the current admission. He also described right upper extremity tingling and occasional numbness, but he denied other neurologic complaints.

The course of adrenomedullin and endothelin levels in patients with vasodilatory shock after cardiac surgery compared to patients after uncomplicated elective cardiac surgery.

The aim of this study was to analyse the course of adrenomedullin (ADM) and endothelin-1 (ET-1) levels in patients with vasodilatory shock after cardiac surgery and to explore differences compared to patients after uncomplicated coronary artery bypass graft (CABG) surgery. ADM and ET-1 are involved in the vasomotor response during vasodilatory shock. We included 32 patients with vasodilatory shock (study group) and 10 patients after uncomplicated CABG surgery (control group). Daily measurements of MR-proADM and CT-proET-1 (stable surrogate markers for ADM and ET-1) were collected during the first 7 postoperative days. MR-proADM and CT-proET-1 levels were significantly elevated in the study group when compared to the control group. In addition, the course of both biomarkers was significantly different in the study versus control group. Higher levels of both biomarkers were associated with organ dysfunction (higher maximum multiple organ dysfunction score, acute kidney injury). Significantly higher levels of MR-proADM and CT-proET-1 and a different course of both biomarkers were observed in patients with vasodilatory shock after cardiac surgery and seemed to be associated with organ dysfunction.

Marked reduction in right ventricular longitudinal contraction after cardiopulmonary bypass in patients with preserved right ventricular output

Introduction Assessment of right ventricular (RV) function is crucial since RV failure with a reduced cardiac output is associated with compromised outcome in cardiac surgery. Echocardiographic evaluation of RV function is commonly used, and a reduction in tricuspid annular plane systolic excursion (TAPSE) and tricuspid annulus tissue Doppler imaging (S’) have been observed independently of clinical signs of RV failure. This has led to uncertainty of these variables’ ability to reflect RV function in cardiac surgery [1]. The objective of this study was to describe changes in transoesophageal echocardiographic (TEE) measurements of TAPSE and S’ during coronary artery bypass graft (CABG) surgery with detailed haemodynamic monitoring using pulmonary artery catheter (PAC) assessment of RV output in patients undergoing uncomplicated CABG without RV impairment. Methods We prospectively studied 30 patients with concomitant PAC and TEE measurements at four time-points, namely after: anaesthesia induction, sternotomy, cardiopulmonary bypass (CPB) and upon arrival in the intensive care unit (ICU). Results TAPSE and S’ were significantly reduced by 43% (p Discussion TAPSE and S’ were both reduced after CPB despite maintained cardiac output. RVFAC, RVEF and RV-GLS remained stable, however, these measures were unable to detect minor changes in SV. 3D-echocardiography showed a strong correlation with SV measured by thermodilution, but with a consistent underestimation of approximately 10%. Our results suggest that 3D echocardiography is better at tracking RV output than other echocardiographic modalities, however, the clinician should be aware that 3D echocardiography underestimates SV compared to thermodilution.

Effect of Respiratory Physiotherapy in Preventing Pulmonary Complications in Post CABG: A Cross-Sectional Study at LUH Hyderabad, Pakistan

Background: The efficacy of physiotherapy techniques used for patients following uncomplicated coronary artery bypass graft (CABG) surgery is well documented. According to previous literature some of the evident techniques were adopted into practice by cardiothoracic nurses. Aims and objectives: The aim of this study was to identify the current physiotherapy interventions used for following uncomplicated CABG surgery patients, and to establish the currently evidence-based practice in nursing staff for CABG surgery patients in cardiothoracic ward. Methods: Using purposive sampling the structured questionnaire was distributed among 10 nurses working in the cardiac ward with response rate 100%.Results: The results of the study revealed that most common postoperative pulmonary complications in cardiothoracic ward were pleural effusion (90%), pulmonary embolism (60%), pneumothorax (50%) and acute respiratory syndrome (40%). The routinely physiotherapy techniques which were used to prevent from postoperative pulmonary complications were chest physiotherapy (90%), splinting while cough (80%), and incentive spirometry (50%).Conclusion: In conclusion nurses used physiotherapy techniques for treating patients following uncomplicated CABG patients such as chest physiotherapy, splinting while cough and incentive spirometry that are supported by the available evidence. This survey provides an insight into physical therapy practice cardiothoracic surgery nurses. Standardized guidelines may be required for nurses to practice better according to clinical care pathway.

Tricuspid annular plane systolic excursion is significantly reduced during uncomplicated coronary artery bypass surgery: A prospective observational study

ObjectivesLongitudinal shortening constitutes most of the right ventricle (RV) contraction in the normal heart. However, after even uncomplicated cardiac surgery with preserved RV function a significant and sustained decrease in longitudinal contraction expressed as a reduction in tricuspid annular plane systolic excursion (TAPSE) has been observed. Why and exactly when this happens remains unsettled. The aim of this study was to evaluate the magnitude and timing of changes in TAPSE in relation to sternotomy, pericardial opening, cardiopulmonary bypass (CPB), and chest closure. MethodsFifty patients with normal preoperative ejection fraction and no valvulopathy, who underwent coronary artery bypass grafting with the use of CPB, were included. TAPSE was assessed using transthoracic echocardiography (TTE) at baseline and immediately after chest closure. Transesophageal echocardiography was performed at the following time points: after (1) anesthesia induction and transthoracic echocardiography; (2) sternotomy; (3) pericardiotomy; (4) completion of CPB; and (5) chest closure. ResultsTAPSE was significantly reduced to approximately half of its initial value in all patients (from 22 [95% confidence interval, 21-23 mm] after anesthesia induction to 9 [95% confidence interval, 8-10 mm] after chest closure). No change was seen after pericardiotomy. The most prominent reduction (30%-40%) was observed after weaning from CPB. An additional significant decrease of 13% to 16% was seen after chest closure. ConclusionsTAPSE was consistently reduced to approximately half of its initial value after uncomplicated coronary artery bypass grafting surgery. The reduction happened mainly after weaning from CPB, possibly reflecting conformational change of the RV.

Recombinant Factor VIII Measurement in a Hemophilia A Patient Undergoing Cardiopulmonary Bypass–Supported Cardiac Surgery

Patients with hemophilia A (Hem A) requiring cardiopulmonary bypass–supported cardiac surgery pose unique challenges for perioperative hemostatic management. This report describes a staged perioperative approach to clinical hematologic management as applied to an 80-year-old male of O-positive blood type with mild Hem A, who underwent successful, uncomplicated coronary artery bypass graft surgery. Hematologic management primarily consisted of normalization of plasma factor VIII levels followed by standard care. Conventional laboratory methods and point-of-care-testing methods such as thromboelastography and heparin management assays were combined to guide patient care. Minimal blood loss and minimal hemodilution techniques were also used to achieve favorable outcomes. The thorough preparation and execution of care by our multidisciplinary team from perfusion, pathology and laboratory medicine, cardiovascular surgery, transfusion services, nursing, and anesthesia, facilitated a safe, smooth, clinical course and an optimal outcome.

The implementation of an intensity regulated exercise programme in coronary artery bypass graft surgery patients: A pilot randomised controlled trial

AIM: To determine the safety and effect of an intensity regulated exercise programme, compared to a structured usual care mobilisation protocol, on the functional capacity of patients following coronary artery bypass graft (CABG) surgery, at discharge and 10 - 14 days after discharge. METHODS: Single centre, double-blinded, randomised controlled trial at a private hospital in Cape Town, South Africa. Subjects in the exercise group performed an intensity regulated exercise programme, while subjects in the control group were encouraged to mobilise out of bed. Both programmes were implemented within 24 hours after extubation following uncomplicated CABG surgery. Functional capacity was tested by means of the Six-Minute Walk Test (6MWT) at discharge and 10 - 14 days after discharge. RESULTS: Eligible patients (n=38) were randomly allocated to an exercise group (n=17) or a control group (n=21). The functional capacity of subjects in the exercise group was signifi cantly higher than that of the control group at hospital discharge, mean difference 103.10 meters (95%CI 23.39 - 182.81) (p=0.01). The exercise group did not further improve after hospital discharge (p=0.3) whereas the control group showed a signifi cant improvement (p<0.01) in walking distance over time. The mean difference in 6MWD at the second test was 44.89 meters (95%CI -84.33 - 174.10) (p=0.47). CONCLUSION: An intensity regulated exercise programme leads to higher levels of functional capacity on discharge and should be encouraged in the in-patient phase of cardiac rehabilitation following CABG surgery.

Comparative Study on Effects of Active Cycle of Breathing Technique and Manual Chest Physical Therapy after Uncomplicated Coronary Artery Bypass Grafting Surgery

Comparative Study on Effects of Active Cycle of Breathing Technique and Manual Chest Physical Therapy after Uncomplicated Coronary Artery Bypass Grafting Surgery

Early Aerobic Exercise after Coronary Artery Bypass Surgery: A Systematic Review

Introduction: Aerobic exercise (AE) reduces morbidity and mortality for patients following coronary artery bypass graft (CABG) surgery. AE is commonly commenced at least 4 weeks following CABG during outpatient cardiac rehabilitation. AE in the early postoperative period may improve aerobic and functional capacity of patients at hospital discharge. The aim of the present study was to assess the outcomes of early AE following CABG. Methods: A systematic review of the literature was conducted for studies published on outcomes of patients undergoing early (commencing within 2 weeks of CABG) aerobic or functional exercise training. Predefined inclusion criteria included studies reporting on early (<4 weeks) outcomes. Results: Seven studies were identified according to selection criteria. A total of 473 patients received early AE interventions. Functional capacity when measured by 6-minute walk test (6MWT) was higher in early AE groups (mean = 404.6m) compared with control groups (mean = 378m). Mean ventilatory anaerobic threshold following early AE was 12.15 ml/kg/min and mean peak oxygen uptake was 18.2 ml/kg/min. Early postoperative outcomes included atrial fibrillation (22.9%), deep sternal wound infection (0%) and mortality (0%). Discussion: This study is the only review of early exercise following CABG identified from the current literature. Our results indicate that early AE can be safely performed in selected patients following uncomplicated CABG, with improvements in functional and aerobic capacity in the early postoperative period. Future studies should focus on patient cohorts at higher risk of acute functional or aerobic deconditioning such as the elderly, obese and those with functional limitations from comorbidities.

Does retrograde autologous priming of the cardiopulmonary bypass circuit have an impact on haematocrit and blood transfusion in uncomplicated coronary artery bypass graft surgery? A retrospective analysis

Haemodilution occuring as a result of cardiopulmonary bypass prime volume increases the need for transfusion of allogenic blood products. Many techniques have been employed to reduce the same. Priming the CPB circuit with the patient's own blood is thought to decrease haemodilution and transfusion requirements.

Sequelae of radiotherapy-induced coronary artery disease in breast reconstruction

Sir, Approximately 37% of breast cancer patients who undergo breast conserving surgery or are found to have positive lymph nodes receive adjuvant radiotherapy [1]. Known side-effects of radiotherapy include wound breakdown, scarring, and radiation-induced angiosarcoma [2]. Less commonly cardiovascular complications can occur secondary to unwanted indirect irradiation of the heart, including coronary artery disease, pericarditis, and cardiomyopathy [3]. Chemotherapy for breast cancer can also induce cardiotoxicity, mainly secondary to anthracycline chemotherapy, which can lead to irreversible heart failure [4]. Cardiotoxicity has also been described with fluorouracil (5-FU) as angina-like chest pain, with incidences ranging from 1 to 68 % in the literature; cardiac events occur generally within 5 days after first administration [4]. We present an interesting case of a 45-year-old lady who underwent left mastectomy for breast cancer. This was followed by non-anthracycline chemotherapy and adjuvant radiotherapy receiving a total of 40 Gy over a course of 3 weeks. Two years later, she underwent delayed left breast reconstruction with a pedicled extended latissimus dorsi (ELD) musculocutaneous flap with a 220 cc round textured implant. She completed 5 years of tamoxifen and breast follow-up without any complications and remained diseasefree. Seven years after completion of radiotherapy, she presented to the emergency department with syncopal episodes and a four week history of exertional angina. Although she thought this pain was implant-related, her blood results showed a positive troponin (peak of 75 ng/L) and ECG’s showed T wave inversion in all the anterior leads, indicating an acute myocardial infarction. Coronary angiogram revealed critical coronary disease involving the left anterior descending, left circumflex and right coronary arteries (i.e. triple vessel disease). Her general risk factors were that she was an ex-smoker (2 pack years) with a family history of coronary heart disease. The cardiologists believed that her left-sided breast radiotherapy was the main predisposing factor for such unique triple vessel disease in a young patient. She was referred for urgent coronary artery bypass graft (CABG). Though the preoperative CT showed that the medial margin of the left breast implant was near the mid-sternal line (Fig. 1), this was probably positional, as clinically it appeared aesthetically acceptable (Fig. 2a). The patient underwent an uncomplicated triple CABG, and the left breast implant was preserved as it had not encroached the median sternotomy incision. Her postoperative breast aesthetic appearance remained unchanged (Fig. 2b). This letter highlights an interesting case of radiotherapyinduced triple vessel coronary artery disease and subsequent acute myocardial infarction in a young woman, following left sided irradiation for breast cancer. Microscopically, endothelial injury may occur secondary to the formation of reactive oxygen species and the activation of lysosomal enzymes within intima and media. Radiation promotes the adhesion of endothelial cells and the release of VonWillebrand factor inducing a prothrombotic state. Overall, atherosclerosis is * Hazim Sadideen hazim.sadideen@doctors.org.uk

Changes in Right Ventricular Shape and Deformation Following Coronary Artery Bypass Surgery-Insights from Echocardiography with Strain Rate and Magnetic Resonance Imaging.

This study was designed to assess whether altered RV geometry and deformation parameters persisted well into the recovery period after presumably uncomplicated coronary artery bypass grafting (CABG). It was our hypothesis that the altered geometry of and load in the RV following pericardial opening would change both regional and global deformation indices for an extensive period postoperatively. Fifty-seven patients scheduled for CABG underwent preoperative and 8-10 months postoperative magnetic resonance imaging (MRI) for RV volume measurements, and resting echocardiography with assessment of geometry and RV mechanical function determined by tissue Doppler imaging (TDI) based longitudinal strain. Both MRI and echocardiography revealed postoperative dilatation of the RV apex, shortened longitudinal RV length but unchanged RV ejection fraction. Echocardiography parameters associated with filling of the right atrium showed signs of constraint with a reduced systolic filling fraction and increased right atrial size. Right ventricular segmental strain (-20 ± 13% vs. -29 ± 20% preoperatively; mean ±SD, P < 0.0001) was reduced postoperatively in parallel with TAPSE (1.3 ± 0.3 cm vs. 2.2 ± 0.4 cm; P < 0.0001). Post-CABG longitudinal motion of the RV lateral wall is reduced after uneventful CABG despite preserved RV ejection fraction and stroke volume. The discrepancy in various RV systolic performance indicators results from increased sphericity of the RV following opening the pericardium during surgery. Therefore, longitudinal functional parameters may underestimate RV systolic function for at least 8-10 months post-CABG. Changes in deformation parameters should thus always be interpreted in relation to changes in geometry.

Increased late mortality after coronary artery bypass surgery complicated by isolated new-onset atrial fibrillation: A comprehensive propensity-matched analysis

The association of new-onset postoperative atrial fibrillation (POAF) and late death after coronary artery bypass grafting (CABG) has been confounded by the frequent concomitant serious complications that co-occur with POAF. We aimed to define the magnitude and time dependence of the effect of isolated POAF on late survival after uncomplicated CABG to comprehensively account for comorbidity and perioperative confounding factors. Nonsalvage CABG patients with no history of AF, no concomitant aortic or valvular surgery, and no perioperative complications other than POAF were studied (n=6305). Patients were divided into AF (n=1211, 68 years old, 72% male) and no-AF (n=5094, 63 years old, 70% male) groups. Propensity matching was done using 55 patient variables, including coronary grafts, completeness of revascularization, and transfusion data. The AF effect was quantified using time-segmented hazard ratios by Cox regression analysis. Single (1-to-1), double (1-to-2), and triple (1-to-3) propensity matching of the AF and no-AF was achieved for 1196, 993, and 719 cases, respectively. The AF group showed significantly worse, yet time-varying, 0- to 18-year survival: 0 to 1 year, HR, 1.18 (95% confidence interval, 0.77-1.81); 1 to 6 years, HR, 1.37 (95% confidence interval, 1.12 to 1.67); and 6 to 17 years, HR, 1.25 (95% confidence interval, 1.05 to 1.49). Isolated POAF was associated with a time-varying increase in mortality after CABG. Given these findings and the high incidence of POAF, efforts to reduce POAF should be pursued to potentially improve resource usage, morbidity, and mortality.

Does Mild Renal Failure Affect Coronary Flow Reserve after Coronary Artery Bypass Graft Surgery?

There are only a limited number of studies on the link between mild renal failure and coronary artery disease. The purpose of this study is to investigate the effects of mild renal failure on the distal vascular bed by measuring the coronary flow reserve (CFR) in transthoracic echocardiography after coronary artery bypass grafting (CABG). The study included 52 consecutive patients (12 women and 40 men) who had undergone uncomplicated CABG. The patients were divided into 2 groups. Group 1 included patients with a preoperative glomerular filtration rate (GFR) of 60-90 (mild renal failure), and group 2 included those with a GFR >90. The CFR measurements were carried out through a second harmonic transthoracic Doppler echocardiography. The mean age was 60.08 ± 1.56 years in group 1 and 60.33 ± 1.19 in group 2. The mean preoperative CFR was 1.79 ± 0.06 in group 1 and 2.05 ± 0.09 in group 2. The mean postoperative CFR was 2.09 ± 0.08 in group 1 and 2.37 ± 0.06 in group 2. There was a statistically significant difference between the 2 groups as to preoperative creatinine clearance, preoperative estimated GFR, postoperative day 7 creatinine clearance, postoperative month 6 creatinine clearance, postoperative day 7 estimated GFR, postoperative month 6 estimated GFR, preoperative CFR, and postoperative CFR (P < .05). CFR was found to be unaffected by the choice of on-pump or off-pump technique (P = .907). After bypass surgery, there was a significant increase in the mean postoperative CFR, when compared with the mean preoperative CFR (P = .001). In our study, we detected a decrease in CFR in patients with mild renal failure. We believe that in patients undergoing CABG for coronary artery disease, mild renal failure can produce adverse effects due to deterioration of the microvascular bed.

Fatal pulmonary embolism complicating a postoperative chylothorax despite adequate thromboprophylaxis

Chylothorax is a recognized complication of intrathoracic surgery, but its occurrence after coronary artery bypass grafting (CABG) is very rare. We report a case of a fatal pulmonary embolism as a complication of chylothorax following CABG. The patient was an 82-year-old woman who presented with increasing chest pain 2 weeks after discharge after an uncomplicated CABG. A computerized tomography (CT) scan with contrast angiogram showed a left-sided pleural effusion and no concurrent pulmonary embolus. Analysis of the pleural effusion revealed a chylothorax, which was treated with chest tube drainage and total parenteral nutrition followed by an oral medium-chain fatty acid diet. The patient improved steadily but, on day 6, she developed acute hypoxemic respiratory failure and shock. A CT angiogram revealed a massive pulmonary embolus and, despite thrombolysis, the patient died. Autopsy confirmed an acute saddle embolus in the pulmonary trunk. The patient had received appropriate venous thromboembolism prophylaxis with subcutaneous unfractionated heparin during her hospital course. This is the first reported case of a fatal pulmonary embolism that occurred in the setting of a post-CABG chylothorax in adults. The occurrence of this complication despite unfractionated heparin thromboprophylaxis may suggest a role for other, more effective medications, such as low molecular weight heparin or fondaparinux in patients with chylothorax.

Is it better to shine a light, or rather to curse the darkness? Cerebral near-infrared spectroscopy and cardiac surgery

Cerebral perfusion and good neurological outcome appear most obviously at risk during operations on the aortic arch. However, it is also evident that from a numerical standpoint, otherwise uncomplicated coronary artery bypass grafting (CABG) accounts for the greatest number of perioperative strokes, as shown in a review of 7839 patients in which it was determined that the overall incidence of clinical stroke immediately apparent at extubation was 1.4% and that in addition to severe aortic calcification, cardiopulmonary bypass (CPB) time was also an independent risk factor [1]. Similarly, in a previous study of 13 897 CABG patients, it was also noted that the duration of CPB increased the risk of hypoperfusion strokes and that ‘nearly 75% of all strokes occurred among the 90% of patients at low or medium preoperative risk’ [2]. These facts indicate that the duration of CPB and inadvertent cerebral hypoperfusion can directly influence the risk of perioperative stroke and adverse neurological outcomes. Clearly, for most patients undergoing cardiac surgery, survivorship is of first importance, but it is also readily apparent that for many patients, the risk of severe neurological injury, stroke and significant cognitive impairment are ever-present and particularly feared concerns [3].