Coronary Bypass Graft Surgery Research Articles

Reassessing the importance of complete versus incomplete coronary revascularization.

Coronary revascularization may be performed for relief of anginal symptoms or, in specific patient subgroups, to reduce the incidence of myocardial infarction and mortality. Achieving complete revascularization of all significantly obstructed coronary segments has been an established goal of coronary bypass graft surgery (CABG) and more recent data demonstrate a salutary effect of complete revascularization following percutaneous coronary intervention (PCI) on long-term clinical outcomes as well. Incomplete coronary revascularization is associated with increased mortality following both CABG and PCI, as well as with an increased incidence of myocardial infarction, repeat revascularization, and major adverse cardiovascular or cerebrovascular events following PCI. The relationship between completeness of revascularization and late adverse clinical outcomes is both qualitative and quantitative as reflected by the residual SYNTAX score (angiographic lesion complexity) following PCI. Thus, complete revascularization has evolved as an important objective for either CABG or PCI and the ability to achieve complete revascularization should enter into the decision algorithm for choice of revascularization modality.

Abstract P454: The Predictors of Non-adherence of Regular Physical Activity After Coronary Revascularization

Background: Coronary heart disease the leading cause of mortality worldwide and regular physical activity is a comprehensive management strategy for these patients. We investigated the parameters that influence regular physical activity in patients with a history of coronary revascularization. Methods: We included outpatients who had a history of coronary revascularization at least 6 months prior to enrollment. A questionnaire was filled out with each patient to collect the data of engagement in regular physical activity, demographics, clinical characteristics, and dietary adherence. Results: We enrolled 202 consecutive outpatients (age 61.3±11.2 years, 73% males). The median duration after revascularization was 60 months. One hundred and 4 (51%) patients had previous percutaneous coronary intervention, 67 (33%) patients had coronary by-pass graft surgery, and 31 (15%) patients had both of the revascularization procedures. Of all, 46 (23%) patients were engaging in regular physical activity with a median of 2 days per week. Patients were classified into two subgroups according to their physical activity habits. There was no significant difference in age, comorbid conditions or revascularization type between subgroups. In the univariate regression analysis, absence of regular physical activity was associated with female gender, low education level, unemployment, low household income, implantation of bare metal stent (vs. drug eluted stent) and absence of regular follow-up visits. Stepwise multivariate regression analysis concluded that low education level (p=0.01, OR=3.26, 95%CI: 1.31 -8.11), and absence of regular follow-up visits (p=0.04, OR=2.95, 95%CI: 1.01-8.61) were independent predictors of non-adherence of regular physical activity in study subjects. Conclusion: Regular physical activity rates were lower in outpatients with a history of previous coronary revascularization. Education level and regular follow-up visits could influence physical activity adherence in these patients.

Is the advantage of coronary bypass graft surgery over percutaneous coronary intervention in diabetic patients with severe multivessel disease influenced by the status of insulin requirement?

Several studies have shown that coronary artery bypass graft surgery (CABG) is superior to percutaneous coronary intervention (PCI) in patients with diabetes and multi-vessel disease. Whether this advantage of CABG over PCI is confined to diabetics who require insulin is unknown. We review the published literature comparing CABG with PCI in diabetics including 8 cohorts and 4,786 patients. There was a lower rate for all-cause mortality (Relative risk (RR): 0.78, 95% confidence interval (CI): 0.62–0.99), and for major adverse cardiac and cerebrovascular events (MACCE, RR: 0.59, 95% CI: 0.47–0.75) for CABG compared to PCI. Composite outcome of mortality, myocardial infarction and stoke was similar between CABG and PCI (RR: 0.87, 95% CI: 0.54–1.42). Visual inspection of the forest plots showed that in most analyses, the point estimates of the RR are similar between the insulin requiring group and non-insulin requiring group. On meta-regression, there was no interaction between status of insulin requirement and revascularization strategies (P > 0.05 for all). The presented data on the still unpublished analysis of the FREEDOM trial showed similar results. Thus, in the current era, CABG is superior to PCI with lower mortality and MACCE rates, but the state of insulin requirement had no effect on the outcomes from the two revascularization strategies.

Thymoma Following Coronary Bypass Graft Surgery

Thymoma Following Coronary Bypass Graft Surgery

STRUCTURE OF COGNITIVE DISORDERS AND DYNAMICS OF BIOELECTRIC ACTIVITY OF THE BRAIN IN PATIENTS AFTER DIRECT MYOCARDIAL REVASCULARIZATION

Aim. To analyze structural chareacteristics and electroencephalographic (EEG) pattern of post-operation cognitive dysfunction (POCD) in patients after direct myocardial revascularization under artificial circulation (AI). Material and methods. Totally 114 male-patients included, underwent scheduled coronary bypass grafting (CBG) under the AI, with average age 55,9±5,3 y. In 3-5 days before operation and on 7-10 day after all patients underwent neurophysiological testing; of those 65 patients also underwent EEG. Results. The CBG operation with AI leads in 79% of cases to the early POCD. Cognitive impairment usually becomes prominent in the domains of neurodynamics and memory. It is shown that the early POCD is followed by EEG-signs of cortical dysfunction (increase of low-frequency theta-rhythm magnitude). Conclusion. According to the results of the study, in post-operative CBG with AI period the structure of POCD consists of injury of neurodynamics and memory, which might be a cause of decreased life quality of patients and efficacy of surgery itself.

Aspirin Resistance in Patients Undergoing Coronary Artery Bypass Grafting = مقاومة الأسبرين في المرضى الذين يخضعون لعملية تطعيم الشرايين التاجية

Objective: Aspirin is a very common drug used after coronary artery bypass grafting. Significantly it is known to reduce mortality and the rate of ischemic complications after CABG. Resistance to Aspirin is a well known entity and has a great influence on clinical outcome. Our study will investigate the phenomenon of aspirin resistance in our patients that underwent coronary artery bypass surgery. Methods: In a prospective controlled study 100 patients undergoing coronary artery bypass grafting (CABG) were included to investigate their sensitivity to Aspirin using platelets aggregometry study. Patients were followed up after one year to show their clinical outcome. Results: 25 patients (25%) showed normal reaction to Aspirin (sensitive to treatment). 24 patients (24%) were preoperatively resistance to Aspirin and 51 patients (51%) developed this resistance postoperatively. The use of cardiopulmonary bypass, pump time and type of procedure showed no influence on the resistance rate. The one year follow up showed 5 deaths in the group of patients that developed the resistance preoperatively whereas resistance disappeared completely after one year in the perioperative resistant group. Conclusions: Aspirin resistance occurs in a large portion of patients that undergo open heart surgery for coronary artery bypass grafting. It doesn’t appear to last permanently but rather for a brief period. The worse outcome for patients with Aspirin resistance could be assumpted by the increase mortality in this group.

A comparative clinical study of dexmedetomidine versus placebo to attenuate hemodynamic response to endotracheal intubation in patients undergoing off pump coronary arterial bypass grafting

Context: Direct laryngoscopy and endotracheal intubation are the most stressful periods during induction of anesthesia. These events can lead to hypertension, tachycardia, arrhythmias and myocardial ischaemia. Aims: (1) To evaluate the haemodynamic response to laryngoscopy and endotracheal intubation with a single preinduction infusion of dexmedetomidine (DEX) 1 μg/kg over a 10 min period, (2) To assess the incidence of side effects, that is, rebound hypertension, bradycardia and hypotension etc., associated with the use of DEX. Settings and Design: This was a prospective, double-blind, parallel group randomized clinical trial of DEX (1 μg/kg) before anesthetic induction to study the attenuation of hemodynamic response to endotracheal intubation in 60 adult patients undergoing elective off pump coronary arterial bypass grafting. Materials and Methods: Patients were randomly allocated to receive either DEX (DEX group, n = 30) or 0.9% normal saline (PLA group, n = 30). Hemodynamic variables were recorded at baseline (Abbreviated as TB), after completion of drug infusion (Abbreviated as TC), 3 min after induction and immediately before intubation (T0), at the 1 st (T1), 3 rd (T3) and 5 th (T5) min after intubation. Statistical Analysis Used: The data are presented as mean ± standard deviation. Demographic data were analysed by Student's t-test between the two groups. Analysis of variance for repeated measures f-test was used to analyze changes over time. A P < 0.05 was considered as significant and P < 0.01 or 0.001 was considered as highly significant. Results: All the hemodynamic variables were comparable in both groups at baseline. Heart rate values were statistically significantly lower in the DEX group at TC and highly statistically significantly lower at T1, T3 and T5 values. Systolic blood pressure values were statistically significantly lower in the DEX group at T0 and highly statistically significantly lower at T1, T3 and T5. Diastolic blood pressure and mean blood pressure values and systolic pulmonary artery pressure values were highly statistically significantly lower in the DEX group at T1, T3 and T5. Diastolic pulmonary artery pressure were statistically significantly lower in the DEX group at TC, T0 and T1 and highly statistically significantly lower at T3. Mean pulmonary artery pressure were statistically significantly lower in the DEX group at T0 and highly statistically significantly lower at TC, T1 and T3. Arterial oxygen saturation was statistically significantly lower in the DEX group at TC. There was no case of hypotension or bradycardia in our case series. Conclusions: Dexmedetomeditine (1 μg/kg) attenuates hemodynamic response to laryngoscopy and intubation in elective surgery for off pump coronary artery bypass grafting.

Nitroglycerine induced acute myocardial infarction in a patient with myocardial bridging.

Muscle overlying an intramyocardial segment of a coronary artery is termed a myocardial bridge. The intramyocardial segment, the tunneled artery, is compressed during systole. The condition is generally benign but may occasionally cause myocardial ischemia, infarction, arrhythmia, or sudden cardiac death. We present a case regarding a 52-year-old man with exercise-induced angina who was diagnosed with a myocardial bridge overlying the left anterior descending artery. He was initially treated with beta-blockers and later received coronary bypass graft surgery.

ANALYSIS OF RENAL FUNCTION AFTER ON AND OFF PUMP CORONARY ARTERY BYPASS GRAFTING

Cardiopulmonary bypass (CPB) is often associated with renal dysfunction, as measured by plasma creatinine levels and hemodialysis rates. Aim. To compare creatinine clearance (CrCl), estimated with the Cockroft and Gault formula, between patients undergoing off-pump coronary artery bypass grafting (OPCAB) versus on-pump CABG (on-CAB). Material and methods. Between April 2008 and April 2009, 119 patients underwent coronary bypass graft surgery. Fifty-eight (58) of these patients underwent OPCAB while 61 had on-CAB. Creatinine clearance, plasma creatinine levels, and clinical outcome were compared between the groups. A creatinine clearance value of 50 mL/minute was accepted as the lowest limit of normal renal function. Results. There were two hospital deaths caused by sepses after pulmonary infection. Creatinine clearance (Preoperative OPCAB 73,64±33,72 x on-CAB 75,70±34,30mL/min; discharge OPCAB 75,73±35,07 x on-CAB 79,07±34,71 mL/ min; p=0,609), and creatinine levels (Preoperative OPCAB 1,04±0,38 x on-CAB 1,13±0,53 mg/dL; discharge OPCAB 1,12±0,79 x on-CAB 1,04±0,29mg/dL; p=0,407) did not show statistically inter-group differences. Conclusion. Deterioration in renal function is associated with higher rates of postoperative complications. No significant difference in CrCl could be demonstrated between the groups.

Frequency and outcomes of aortocoronary dissection during percutaneous coronary intervention of chronic total occlusions

Aortocoronary dissection can complicate percutaneous coronary intervention (PCI) of chronic total occlusions (CTOs). We retrospectively examined the frequency and outcomes of aortocoronary dissection among 336 consecutive CTO PCIs performed at our institution between 2005 and 2012 and performed a systematic review of the published literature. Aortocoronary dissection occurred in six patients (1.8%, 95% confidence intervals 0.7%, 3.8%). All aortocoronary dissections occurred in the right coronary artery (CTO target vessel in five patients and donor vessel in one patient). The baseline clinical characteristics of patients with and without aortocoronary dissection were similar. Compared to patients without, those with aortocoronary dissection were more likely to undergo crossing attempts using the retrograde approach (25% vs. 67%, P = 0.036) and experience a major complication (2.4% vs. 33.3%, P = 0.008). Technical and procedural success rates were similar in both groups. Of the six patients with aortocoronary dissection one underwent emergency coronary bypass graft surgery (CABG), four were treated with ostial stenting, and one was treated conservatively without subsequent adverse clinical outcomes. Systematic literature review provided 107 published cases of aortocoronary dissection during PCI, that occurred mainly in the right coronary artery (74.8%) and were treated with stenting (49.5%), emergency CABG (29%), or conservatively (21.5%). Aortocoronary dissection is an infrequent complication of CTO PCI and although it can be treated with stents in most patients, it may infrequently require emergency CABG.

Prevalence of interatrial block in patients undergoing coronary bypass graft surgery

Prevalence of interatrial block in patients undergoing coronary bypass graft surgery

Preoperative CYP2D6 metabolism-dependent β-blocker use and mortality after coronary artery bypass grafting surgery

Recently, the role of β-blockers (BBs) in reducing perioperative mortality has been challenged. The conflicting results might have resulted from the extent of BB metabolism by the cytochrome P-450 (CYP2D6) isoenzyme. The purpose of the present study was to assess the association between the preoperative use of BBsdependent on metabolism of the CYP2D6 isoenzyme with operative mortality after coronary artery bypass grafting surgery. We performed a retrospective study of 5248 patients who had undergone coronary bypass grafting surgery from January 1, 2001 to November 30, 2009 at Duke University Medical Center. The cohorts were defined by the preoperative use of BBs and BB type (non-CYP2D6_BBs, CYP2D6_BBs, or no BBs). Operative mortality was analyzed using inverse probability-weighted estimators with propensity score adjustment. Of the 5248 patients, 14% received non-CYP2D6_BBs, 43%, CYP2D6_BBs, and 43%, no BBs. The incidence of operative mortality was 0.8%, 2.1%, and 3.7% in the non-CYP2D6_BB, CYP2D6_BB, and no BB groups, respectively. Multivariable inverse probability-weighted-adjusted analyses showed that non-CYP2D6_BBs were associated with a lower incidence of operative mortality (odds ratio, 0.33; 95% confidence interval, 0.13-0.83; P=.02) compared with no BB use and a trend toward lower operative mortality (odds ratio, 0.44; 95% confidence interval, 0.16-1.07; P=.06) compared with CYP2D6_BBs. No significant decrease occurred in the risk of operative mortality between the CYP2D6_BB and no BB groups (odds ratio, 0.85;95% confidence interval, 0.54-1.34; P=.48). Among these patients, preoperative non-CYP2D6_BB use, but not CYP2D6_BB use, was associated with a decreased risk of operative mortality.

CHADS2 and CHA2DS2-VASc Scoring Systems are not Useful for Predicting Postoperative Atrial Fibrillation after Coronary Artery Bypass Graft Surgery

Aim: In recent literature only two data exist whether the CHADS2 and CHA2DS2VASc scores can be used for the risk assessment of new-onset atrial fibrillation (AF) or AF after coronary artery bypass graft (CABG) surgery. Methods: We retrospectively analyzed 133 consecutive patients (42 patients with AF after CABG surgery and 91 patients without AF) who were undergoing CABG between January 2011 and January 2013 at our department. Complete medical records were retrospectively collected to investigate, congestive heart failure, hypertension, age 75 years, diabetes, previous stroke (CHADS2) and CHA2DS2-vascular disease, age 65-74 years, sex category (CHA2DS2-VASc) scores. The primary end point of this study was the development of AF after CABG surgery in hospital. Results: Only age (67.6+9.7 vs 62.4+10.6 years, p1⁄40.008) was significantly higher in AF group. Mean CHADS2 and CHA2DS2-VASc scores were 1.53+0.97 and 3.23+1.25 respectively. CHADS2 (1.62+0.91 vs 1.48+1.00, p1⁄40.34) and CHA2DS2VASc (3.43+1.17 vs 3.13+1.28, p1⁄40.22) scores were higher in AF group but it was not statistically significant. When patients divided into two groups according to CHADS2 and CHA2DS2-VASc scores at the cuttof point of 2, no significant difference was detected in AF rate (31.9% vs 30.0%, p1⁄40.55 and 34.4% vs 24.3%, p1⁄40.18 respectively). In univariate and multivariate analysis only age was independent predictor of AF after CABG surgery (Table 1). Conclusion: CHADS2 and CHA2DS2-VASc scores were not independent predictors of AF after CABG surgery. Further prospective, randomized, controlled trials are necessary to make healthier interpretations on this issue.

Electrophysiological Changes Preceding the Onset of Atrial Fibrillation After Coronary Bypass Grafting Surgery

The incidence of the Post-CABG atrial fibrillation (AF) lies between 25% and 40%. It worsens morbidity and raises the post-operative costs. This study investigates the electrophysiological changes preceding the onset of AF and their relationship to the preoperative risk.

Bilateral skeletonized IMA: in situ grafts for myocardial revascularization

Background Bilateral skeletonized internal mammary artery (IMA) has been recognized as the most advanced surgical option for myocardial revascularization. However, diabetes, chronic obstructive pulmonary disease (COPD) and obesity have been accepted as a limitation for such surgical option. The aim of this study is to evaluate immediate and long term results in patients with bilateral skeletonized IMA used as “in situ” graft for coronary bypass surgery.

Stenting of a left main coronary artery compressed by dilated pulmonary artery

A 54-year-old obese man without comorbidity presented with dyspnea associated with typical angina. Physical examination revealed jugular venous distension, systolic murmur at left parasternal border with a prominent pulmonary component of S2 and S3 gallop. He had ST depression throughout the precordial leads and troponin level of 8. Coronary angiography showed 95% narrowing in the proximal left main coronary artery (LMCA) with TIMI grade 3 flow (Image A, B, C). Echocardiography showed a markedly dilated pulmonary. CT angiography demonstrated compression of the LMCA by the severely enlarged Main pulmonary artery (MPA) (9.8×9.0 cm). Right heart catheterization revealed right ventricle pressure of 69/10 mmHg with mean pressure of 33 mmHg and right pulmonary artery pressure of 66/28 mmHg with mean pressure of 40 mmHg. Work up for the cause of pulmonary hypertension was consistent with primary pulmonary arterial hypertension (PPAH). Stent of the LMCA was performed with 4.5×12 mm bare metal Veriflex™ stent (Boston Scientific Company, Minneapolis, MN) with post-dilation diameter of 5mm.(Image D) Subsequently IVUS revealed adequate expansion of the stent and complete coverage of the lesion.(Image E) After the procedure, the patient reported immediate relief of symptoms. Optimal medical management was continued. Follow-up coronary angiography at 3 months showed a nonstenosed stent (Image F) and at 1 year, he remained asymptomatic. ![Figure][1] Figure 1. Angiographic and IVUS images LMCA compression by dilated MPA in PAH may not be uncommon as previously thought. It is a reversible cause of chest pain associated with PPAH. Traditionally, LMCA stenosis treatment involves coronary bypass graft surgery. However, LMCA stenosis secondary to compression by dilated MPA has been increasingly treated by angioplasty with promising outcome [1]: pending:yes

Harvesting the radial artery.

The radial artery (RA) has emerged as an important arterial graft for coronary bypass surgery. With improving five-year patency rates and increasing uptake, great attention has been focused on the optimal conduit harvesting technique. We herein present our approach to RA harvesting. Prerequisites of a successful harvest include adherence to important anatomical landmarks, protection of the sensory innervation to the volar forearm, and meticulous handling of the RA branches. Regardless of the harvesting methodology chosen, adherence to a "no-touch" technique will optimize the patency and durability of the RA conduit.

Prophylaxis with erythropoietin versus placebo reduces acute kidney injury and neutrophil gelatinase-associated lipocalin in patients undergoing cardiac surgery: a randomized, double-blind controlled trial

BackgroundCardiac surgery-associated acute kidney injury (CSA-AKI) is a common complication following coronary bypass graft (CABG) surgery. Multi-factorial causes of CSA-AKI involve oxidative stress and inflammation. Erythropoietin (EPO) has been shown from many studies to have a reno-protective effect. The present study was conducted to examine the role of EPO in preventing CSA-AKI.MethodsThis prospective, randomized, double-blind, placebo-controlled trial was conducted in the Cardiovascular and Thoracic Unit. One hundred patients randomly received either 200 U/kg of rHuEPO (n = 50) or saline (n = 50) intravenously three days before operation, and rHuEPO 100 U/kg or saline at operation time. The serum creatinine (SCr), estimated glomerular filtration rate (eGFR) and urine neutrophil gelatinase-associated lipocaline (NGAL) were measured in order to evaluate renal injury following CABG.ResultsThe incidence of CSA-AKI was significantly lower in rHuEPO group (14%) when compared with the placebo group (38%; p < 0.01). The mean intensive care unit (ICU) and hospital stays of the rHuEPO group were significantly shorter than the placebo group (p < 0.01). Postoperative increases in SCr and decreases in eGFR were significantly lower in the rHuEPO group than the placebo group (p < 0.05). The mean urine NGAL in rHuEPO group was significantly lower than the placebo group at 3 hr, 6 hr, 12 hr and 18 hr after CABG (p < 0.05), respectively.ConclusionsProphylaxis administration with intravenous rHuEPO before cardiac surgery decreased the incidence of CSA-AKI and urine NGAL with reduced days in ICU and hospital in elective CABG patients.Trial registrationClinicalTrials.gov: NCT01066351

Endovascular Coil Embolization of Behçet Disease–Related Giant Aneurysm of the Right Coronary Artery After Failure of Surgical Suture

A 69-year-old man with Behcet disease (BD) was referred for treatment of a rapidly growing giant aneurysm (38 × 31 mm) of the right coronary artery (RCA), as detected by computed tomography ([Fig. 1][1]A). The patient initially underwent surgery for single coronary artery bypass grafting and RCA

Hypoxemia During One-Lung Ventilation for Robot-Assisted Coronary Artery Bypass Graft Surgery

Robot-assisted coronary artery bypass grafting requires continuous one-lung ventilation (OLV) to evacuate the thoracic cavity. Whether this ventilatory mode subjects patients to serious hypoxemia remains underinvestigated. From 2005 to 2010, all patients receiving robot-assisted coronary artery bypass graft surgery using OLV with active capnothorax for internal mammary artery harvesting and then passive pneumothorax for minithoracotomy direct-vision coronary bypass graft surgery were included. Patients' variables of oxygenation were monitored and compared throughout the whole surgical period. Persistent oxygen desaturation (arterial oxygen pressure <70 mm Hg) refractory to primary managements was defined as a hypoxemic event, and predictors of such events were identified by multivariate regression analysis. A total of 255 consecutive patients were enrolled. Average oxygen saturation decreased modestly during the first stage of OLV with active capnothorax, causing hypoxemic events in 9 patients (4.3%) leading to death in 2 (0.8%), whereas it dropped drastically in the second stage of OLV with passive pneumothorax, resulting in hypoxemic events in 32 patients (12.6%) and death in 1 (0.4%). Multivariate regression analysis identified high pulmonary vascular resistance and low left ventricular ejection fraction as predictors of hypoxemia during internal mammary artery takedown, whereas prolonged procedure and chronic obstructive pulmonary disease were identified as predictors during minithoracotomy bypass grafting. Robot-assisted two-stage coronary artery bypass surgery employing OLV could be complicated by serious hypoxemia especially at the minithoracotomy grafting stage and in patients with specific risk factors. Thus, when managing such patients, invasive monitoring and aggressive treatment of arterial desaturation are mandatory to ensure the patient's safety and procedural smoothness.