Bypass Graft Surgery Research Articles

ERK5 promotes TLR2-dependent up-regulation of inflammatory mediator expression induces by global myocardial ischemia

Global myocardial ischemia and reperfusion [I/R] injury is predominantly associated with heart transplant and coronary artery bypass graft (CABG) surgery. Toll-like receptor-2 (TLR2) is a pivotal pathogen recognition receptor that has a key role in inflammation and injury. The proinflammatory role for ERK5 downstream of TLR2 in global myocardial I/R has not been reported previously. The aim of this study was to investigate to what extent inflammatory stimuli modify the expression by ERK5 of TLR2. Global myocardial I/R was induced in male TLR2+/+ and TLR2−/− mice using heterotopic abdominal heart transplantation model that allows to subject donor hearts to global hypothermic ischemia and blood reperfusion, which very closely stimulates I/R conditions associated with cardiac surgical operations. The results show that inhibition or siRNA knockdown of ERK5 reduces the TLR2-dependent activation of expression of cytokines, attenuated myocardial injury, less oxidative stress and decreased NF-κB activation and indicating that ERK5 promotes cytokine expression downstream of TLR2. We have identified novel aspects of TLR2 signaling in cold myocardial I/R, including that ERK5 activity is required for TLR2 activation.

HÁBITOS DE LA VIDA DE PACIENTES SUBMETIDOS A LA CIRUGIA DE REVASCULARIZACIÓN MIOCÁRDICA EN LA CIUDAD DE RIO GRANDE/RS/BRAZIL.

The aim of this research was to evaluate patient’s life habits after six months of coronary artery bypass graft (CABG) surgery to delineate a profile and direct therapeutic practice. It was conducted a prospective, quantitative and descriptive study. Patients were submitted to CABG in the Santa Casa Cardiology Hospital of Rio Grande/ Rio Grande do Sul/Brazil between 01/01/2011 and 30/06/2011. It was investigated socioeconomic, demographic, behavioral and healthy characteristics through International Physical Activity Questionnaire and Level of Stress Quesrtionnaire. Data were analyzed through SPSS statistic program. Between the nineteen subjects selected, the mean age was 63,8 + 9,6 years. All of them are not used to smoke, to drink and to take care of nutrition, nevertheless 74% was physically inactive and 58% presented physical stress in the alert phase and 69% presented psychic stress in the exhaustion phase. It was concluded that sedentarism and stress are much presented in the life of this group of people. Thus, it became necessary the development of public health actions to promote acute myocardial infarction (AMI) risk factors awareness and health knowledge in general to propose for these subjects a healthy quality life.

Influence of isoflurane on the diastolic pressure-flow relationship and critical occlusion pressure during arterial CABG surgery: a randomized controlled trial.

The effects of isoflurane on the determinants of blood flow during Coronary Artery Bypass Graft (CABG) surgery are not completely understood. This study characterized the influence of isoflurane on the diastolic Pressure-Flow (P-F) relationship and Critical Occlusion Pressure (COP) during CABG surgery. Twenty patients undergoing CABG surgery were studied. Patients were assigned to an isoflurane or control group. Hemodynamic and flow measurements during CABG surgery were performed twice (15 minutes after the discontinuation of extracorporeal circulation (T15) and again 15 minutes later (T30)). The zero flow pressure intercept (a measure of COP) was extrapolated from a linear regression analysis of the instantaneous diastolic P-F relationship. In the isoflurane group, the application of isoflurane significantly increased the slope of the diastolic P-F relationship by 215% indicating a mean reduction of Coronary Vascular Resistance (CVR) by 46%. Simultaneously, the Mean Diastolic Aortic Pressure (MDAP) decreased by 19% mainly due to a decrease in the systemic vascular resistance index by 21%. The COP, cardiac index, heart rate, Left Ventricular End-Diastolic Pressure (LVEDP) and Coronary Sinus Pressure (CSP) did not change significantly. In the control group, the parameters remained unchanged. In both groups, COP significantly exceeded the CSP and LVEDP at both time points. We conclude that short-term application of isoflurane at a sedative concentration markedly increases the slope of the instantaneous diastolic P-F relationship during CABG surgery implying a distinct decrease with CVR in patients undergoing CABG surgery.

Adult cardiac surgery blood/blood product utilization in the post aprotinin era: an 855 patient, community hospital, retrospective experience

Prior to 2008, when it was withdrawn, aprotinin use in cardiac surgery patients was associated with reduced bleeding and blood utilization, but studies linked its administration to increased patient mortality. We investigated (a) blood/blood product utilization between 2008 and 2013 at our community hospital heart center according to the type of surgery performed following the withdrawal of aprotinin and (b) clinical variables associated with increased patient blood utilization. Seven hundred nine patients were retrospectively investigated for blood/blood product utilization. Variables examined were patient age, body surface area (BSA), gender, preoperative creatinine level, hematocrit level, total cell saved blood (CSB) administered, cardiopulmonary bypass (CPB) time, type of surgical procedure performed, and preoperative clopidogrel usage. Variables (categorical and continuous) were placed into a forward stepwise regression model for the continuous outcome, packed red blood cell (PRBC) utilization. The stepwise function utilized a P value threshold of 0.25 for entering the model and 0.1 for leaving the model. For coronary artery bypass graft (CABG) surgery, use of PRBC was 29.26 % (0.75/1.44), of platelets was 14.18 % (0.24/0.72), of fresh frozen plasma (FFP) was 7.34 % (0.19/0.78), and of cryoprecipitate was 10.63 % (0.23/0.97) among our patient sample. [Data expressed as percent patient utilization, mean/S.D. in units transfused]. Increased age, smaller BSA, higher preoperative creatinine level, lower preoperative hematocrit level, longer CPB time, and increased CSB administration was associated with increased PRBC administration (P < 0.0001). At our community heart surgery center, with a multidisciplinary blood conservation program in place, expected increase in blood/blood product utilization following aprotinin withdrawal was not experienced.

Prevention of reperfusion tachyarrhythmia after CABG: magnesium versus lidocaine

Background Reperfusion tachyarrhythmia after aortic cross-clamp (ACC) release is one of the most commonly encountered complications after coronary artery bypass grafting (CABG) surgery, and its control may save these patients. Materials and methods Ninety patients who had undergone CABG surgery were enrolled in this study. Patients were assigned randomly to three groups (30 patients each). The lidocaine group (LIDO) group received lidocaine (2 mg/kg) in 100 ml isotonic saline, the magnesium group (MAGN) group received magnesium (30 mg/kg) diluted in 100 ml of an isotonic saline 0.9% solution, and the control group received 100 ml normal saline by a pump circuit 3-5 min before ACC release. Anesthetic management, weaning protocol from cardiopulmonary bypass, was standardized. All the patients were monitored after the release of ACC and electrical rhythms (including ventricular fibrillation and supraventricular tachyarrhythmia) were recorded. Results Incidences of postrelease of ACC and ventricular fibrillation were lower in the lidocaine and magnesium groups compared with the control group [7 (23%), 4 (13%) vs. 11 (36%)] ( P = 0.042). Also, the incidence of an atrioventricular block postrelease ACC was higher in the lidocaine group compared with the magnesium and control groups [7 (23%) vs. 2 (6%) and 3 (10%), respectively] ( P = 0.039). The need for a temporary pace maker was higher in the lidocaine group compared with the magnesium and control groups [7 (23%) vs. 2 (6%) and 1 (3%), respectively] ( P = 0.044). Also, the total duration of ICU stay was shorter in the magnesium group compared with the lidocaine and control groups. Conclusion The administration of lidocaine and magnesium sulfate before the release of ACC reduced the incidence of ventricular fibrillation. The administration of magnesium shortened the ICU stay in adult patients undergoing CABG surgery by cardiopulmonary bypass. However, the administration of Lidocaine was associated with more transient atrioventricular block.

Impact of dexmedetomidine on hemodynamic parameters and anaesthetic requirement during induction of anaesthesia in coronary artery bypass surgery patients

Introduction: Laryngoscopy and tracheal intubation is associated with profound adverse hemodynamic changes. Coronary artery disease patients have compromised myocardial blood flow and usually have associated hypertension. If the stress response to tracheal intubation is not controlled, it may lead to severe hypertension, arrhythmias and myocardial ischemia. Dexmedetomidine is a new alpha agonist with high potency to control the stress response, pain and tachyarrhythmia. Hence, impact of dexmedetomidine on hemodynamic parameters during tracheal intubation in coronary artery bypass grafting (CABG) surgery patients was evaluated in the study. Methods: Sixty patients undergoing CABG were enrolled in the study. They were divided into 3 groups. Group 1 received thiopentone 3-5mg/kg, group 2 received thiopentone plus lignocaine 1mg/kg and group 3 received thiopentone plus dexmedetomidine 0.5µg/kg prior to laryngoscopy and tracheal intubation. Heart rate (HR), mean arterial pressure (MAP) and cardiac index (CI) were measured before induction, after anaesthetic induction, at laryngoscopy, and 1min, 3min, 6min and 10min after tracheal intubation. The extra amount of fentanyl and thiopentone required controlling hypertension to laryngoscopy and intubation was noted. The values were analyzed with SPSS 20 software with a P value of

The Ability of Elevated Troponin I Values following Cardiac Surgery to Predict 30-Day and Long Term MajorAdverse Cardiovascular Events: A Single Center Experience

Background: The association between elevated troponin levels after coronary artery bypass grafting (CABG) surgery and short term all-cause mortality as well as major adverse cardiovascular events (MACE) is well documented. However, there is paucity of data reported on long term outcomes. Methods: Baseline patient characteristics, perioperative characteristics, and cardiac biomarkers within 24 hours were evaluated prospectively in a consecutive cohort of 419 subjects who underwent cardiac surgery in a single center, from 1 July 2002 through 30March 2007. Death, myocardial infarction, stroke, target vessel revascularization, and composite MACE were abstracted over a median follow-up of 16.8 months. Results: Troponin I values above 4.13 ng/mL were associated with a 45% increased risk for composite MACE (HR 1.45, 95%CI 1.023-2.067, p=0.038) over the first 2 years post cardiac surgery. Additionally, troponin I levels >4.13 n/mL were also associated with worse survival free from MACE (p=0.034). Troponin I values were not predictive of death, myocardial infarction, stroke or target vessel revascularization nor associated with survival free from these events. Multiple pre-, intra-, and periprocedural patient characteristics were associated with increased observed MACE rates to include preoperative ejection fraction <40%, chronic kidney disease, reoperation, and increased cardiopulmonary bypass times. Only EF ≥ 40% was associated with lower observed MACE. Conclusion: A troponin I level above 4.13 ng/mL was associated with a 45% observed increase in composite MACE during the first 2 years following CS. This finding is hypothesis generating only and may suggest measurement of troponin I level 24hrs after the CS may provide valuable prognostic data.

Coronary artery steal syndrome in patient after coronary arteries by-pass surgery and left subclavian artery stenting-is the maintenance of a patent internal mammary artery still necessary?

The use of the left internal mammary artery (LIMA) is preferred for the revascularization of a stenosed or occluded left anterior descending artery (LAD). Occlusion or stenosis of proximal part of the left subclavian artery (LSA) could induce reverse blood flow in LIMA called coronary subclavian steal syndrome (CSSS) and should be revascularized before coronary artery bypass grafting (CABG) surgery with LIMA. If restenosis of previously stented LSA occurs after CABG surgery with LIMA another revascularization is inevitable. However, the revascularization of LSA could reveal that increased blood pressure in LAD persistent through years due to present CSSS could substantially influence blood pressure change in coronary arteries and LIMA graft. This phenomenon can raise the question if it is necessary to maintain patent LIMA-LAD graft.

Pulmonary Arterial Hypertension Associated with Adult Congenital Heart Disease, when Inoperable becomes Operable: A Case Report

Pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD) is one of the most common forms of pulmonary arterial hypertension (PAH). Unlike the other forms, PAH-CHD can be treated surgically closing the extra- or intracardiac shunt if the shunt is left-to-right and the pulmonary vascular resistance (PVR) is low enough (<2,3-operable, 2,3-4,6 WU-borderline operable). If the PAH postoperatively persists the prognosis is even worse than for non-operated patients. Due to the previously mentioned fact the criteria for operability in such cases are often discussed. We report a case of a 54-year-old man who suffers from coronary artery disease (SYNTAX score-23,5) and PAH-CHD. As the patient required coronary artery bypass grafting (CABG) surgery, the atrial septal defect (ASD) was closed (surgically with a patch followed by transcatheter closure with an occluder) as well despite the fact that according to the current guidelines his pulmonary vascular resistance (4,7 WU) was considered too high for the defect to be operable. The patient was given PAH-specific treatment preoperatively in order to lower his PVR. This article describes the case and discusses the disease, its history, the new classification, diagnostics and treatment options.

Minimally Invasive Valve Surgery and Single Vessel Coronary Artery Bypass via Limited Anterior Right Thoracotomy.

Coronary artery bypass grafting with aortic valve replacement (AVR) or mitral valve replacement (MVR) is traditionally performed via sternotomy. Minimally invasive coronary surgery (MICS) and minimally invasive valve surgery have been successfully performed independently. Patients with critical right coronary artery (RCA) stenosis not amenable to percutaneous intervention are candidates for valve replacement and single vessel coronary artery bypass. We present our series of six patients who underwent a concomitant valve and single vessel intervention via right thoracotomy. Between January 2011 and June 2013, six patients underwent right thoracotomy with valve replacement and single vessel bypass. Four aortic and two mitral valves were replaced and all received single vessel RCA bypass using reversed saphenous vein graft. Thoracotomy was via right anterior approach for AVR and right lateral for MVR. The patients were assessed postoperatively for overall outcomes. The average age was 74 years (range 69-81); two patients were elective (AVR-1; MVR-1) and four were urgent (AVR-3; MVR-1). For MICS AVR and MICS MVR, the average cardiopulmonary bypass time was 171 ± 30 and 169 ± 7 minutes and the average aortic cross-clamp time was 122 ± 36 and 112 ± 2 minutes, respectively. Three patients were discharged home, one patient to a nursing home, and two to rehab. No patients required conversion to sternotomy; one patient developed atrial fibrillation, and one sepsis. Concomitant valve replacement and single bypass grafting via right anterior mini-thoracotomy is a viable option for select patients, particularly in non-stentable RCA stenosis. In the appropriate patient population, combined coronary artery bypass grafting and valve surgery can be safely performed via right thoracotomy.

Abstract 10383: Comparative Assessment of Medical Therapy, PCI, or CABG on Clinical Outcomes in Diabetic Patients With Stable CAD According to Coronary Angiography and Left Ventricular Function: Patient-level Meta-analysis of the BARI-2D, COURAGE, and FREEDOM Trials

Introduction: The benefits of optimal medical therapy (OMT) with or without percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) surgery have been evaluated in patients with Type 2 Diabetes Mellitus (T2DM) and stable coronary artery disease (CAD) but analyses have not been stratified by detailed angiographic CAD burden or left ventricular ejection fraction (LVEF). Methods: A patient-level meta-analysis was undertaken among T2DM patients enrolled in COURAGE, BARI 2D and FREEDOM to assess the impact of randomization to OMT, PCI + OMT, or CABG + OMT on a composite end-point of Death/MI/Stroke and stratified by LVEF (≥ 50%, &lt; 50%), 1, 2 or 3 vessel disease (VD) (% diameter stenosis ≥ 50%) and presence or absence of proximal left anterior descending (pLAD) disease. Hazard ratios (HR) for treatment groups were calculated from Cox regression models including all patients adjusting for trial and revascularization stratum in BARI 2D. Multivariable adjustment for risk factors was performed as a sensitivity analysis. Results: There were 5,034 patients included in the analysis (BARI 2D: n=2,368, COURAGE: n=766, FREEDOM: n=1,900) of whom 17% had LVEF &lt; 50%, 29% had pLAD, and 77% had 2 or 3 VD. A total of 1,591 patients were randomized to OMT alone, 2,118 to PCI + OMT, and 1,325 to CABG + OMT. There were 1,116 events during a median 4.5 year follow-up. There was no significant effect on outcomes with OMT vs PCI + OMT irrespective of LVEF, presence/absence of pLAD and number of VD. By contrast, CABG + OMT significantly reduced the risk of Death/MI/Stroke in patients with 2 or 3 VD, irrespective of LVEF and presence/absence of pLAD (see Table). Results were similar with multivariable adjustment. Conclusions: In patients with T2DM and stable CAD, OMT alone appears to be as effective as PCI + OMT while CABG + OMT significantly reduces cardiovascular events in those with multivessel CAD, irrespective of LVEF or presence of pLAD.

Abstract 15016: Calcifications of Aortic Valve, Coronary Arteries and Aorta in 500 Consecutive Patients

Introduction: Diseases presenting with cardiac and vascular calcification are well known and a variety of diagnostic modalities enable detection of calcifications. However, the relationship between calcification of arteries and the aortic valve together with corresponding pathophysiological processes have not been yet unequivocally elucidated. Purposes of the study: An assessment of correlation between presence and severity of calcifications in the aortic valve, coronary arteries, aorta and influence of cardiovascular disease risk factors on prevalence of calcifications in this locations. Material and Methods: The study included consecutive patients over 60 years of age referred for computed tomography imaging of coronary artery disease. A total number of included patients reached 500 subjects. Besides coronary artery calcification (CAC), we evaluated aortic valve calcification (AVC) and ascending aorta calcification (AAC). Computed tomography examinations were performed with a dual-source, 64-slice scanner. Exclusion criteria encompassed: diagnosed aortic valve disease, history of coronary artery angioplasty, bypass grafting or heart valve surgery. Results: AVC was diagnosed in 163 patients (32.6%). Prevalence of CAC and AAC was higher than AVC and amounted to 78.8% and 59.8%, respectively. Aortic valve calcification was more often observed in men than women. Degree of AVC severity was significantly lesser than that of CAC and AAC (p=0.0001, p=0.0001). In our study population, we did not find a significant dependence between presence and severity of AVC and CAC or AAC. However, we did observe a statistically significant relationship between presence and severity of CAC and AAC. In contrast to coronary arteries and the aorta, we did not find significantly increased prevalence of AVC among patients with arterial hypertension, dyslipidemias, diabetes, smokers or patients with elevated BMI. Only sex and age exerted significant influence on development of AVC. Conclusions: Despite some similarities between the process of aortic valve calcification and that involving coronary arteries and aorta, these phenomena are not interrelated. It seems that process of calcification of the aortic valve is significantly different from atherosclerosis.

Abstract 15628: Prevalence of Non-Pulmonary Vein Triggers in Patients With Previous History Of Coronary Artery Bypass Grafting Undergoing Catheter Ablation for Atrial Fibrillation

Introduction: Post-operative atrial fibrillation (AF) is reported in up to 5-40% of patients following coronary artery bypass graft (CABG) surgery. Age-related atrial dilatation and fibrosis, electrical remodeling, autonomic imbalance and post-operative inflammation are few of the many pathophysiological factors that play an important role in the genesis and persistence of post-CABG AF. Recent data on fibroblast-myocyte interaction indicates the central role of cardiac fibrosis in the origin of non-pulmonary vein (non-PV) drivers that serve as a source for maintenance of AF. Therefore, we sought to examine the prevalence of non-PV triggers and their impact on ablation outcome in post-CABG AF patients. Methods: Two-hundred sixty seven patients with history of CABG undergoing catheter ablation for atrial fibrillation were included in this analysis (61±11 years, 69% male, LVEF 50±10%, LA size 41.0±6.8mm, non-PAF 72%). All patients underwent pulmonary vein antrum (PVAI) and posterior wall isolation. Non-PV triggers were defined as ectopic triggers originating from sites other than pulmonary veins such as interatrial septum, superior vena cava, left atrial appendage, coronary sinus, ligament of Marshall, crista terminalis. Those were identified by isoproterenol challenge and were ablated based on operator choice. Results: During ablation, non-PV triggers were detected in 243 (91%) patients. The triggers were most commonly mapped to CS (62%) and LAA (70%). Additional sites of non-PV triggers were LA septum, superior vena cave, crista terminalis and mitral valve annulus. Based on operator choice, non-PV triggers were ablated in 118 of the 243 patients and not targeted in 125 patients. At the end of 32±7 month follow-up after a single procedure, overall success rate was 130 (53.5%). Of the 118 patients undergoing non-PV trigger ablation, 81(68.6%) patients remained arrhythmia-free off anti-arrhythmic drugs compared to 49 of 125 (39.2%) where non-PV ablation was not performed (log rank p &lt;0.001, hazard ratio 3.76 [95% CI 2-6.43]). Conclusion: Our results for the first time demonstrate that non-PV foci are highly prevalent in post-CABG AF patients and ablation of those triggers results in significantly better long-term outcome.

Abstract 9825: Cardiac Strain in a Swine Model of Regional Hibernating Myocardium: Effects of Bypass Surgery on Contractile Reserve

Background: Clinical studies have suggested that functional recovery of hibernating myocardium may be delayed following coronary artery bypass graft (CABG) surgery. We have shown in a swine model of hibernating myocardium, that recovery of regional function and oxygen consumption during an infusion of high dose catecholamine is sub-maximal at 4-weeks following CABG. Using the same swine model of hibernating hearts along with MRI estimates of circumferential strain (ECC), we tested whether contractile reserve within hibernating myocardial regions during a low dose infusion of dobutamine improves post-CABG. Methods. Ten pigs underwent thoracotomy with placement of a constrictor around the LAD artery. At 12 weeks, MRI imaging was performed prior to CABG and repeated 4-weeks following off-pump revascularization with a left internal mammary artery graft to the LAD artery. MRI studies were performed at baseline and during an infusion of low dose dobutamine (5 μg/kg/min). Results: MRI studies prior to CABG showed that circumferential strain in the Hibernating (LAD) Region was lower than the Remote Region at rest (-14.5±0.7 versus -15.1±0.7 respectively; P&lt;0.05) and did not improve during dobutamine (-14.7±0.8 versus -16.7±0.8 respectively; P&lt;0.05). Following CABG, strain measurements in the hibernating LAD region remained lower than remote regions at rest, but improved during the same dose of dobutamine (Figure). Summary: Baseline function in hibernating myocardium does not fully recover at 4 weeks post-CABG but contractile reserve during an infusion of low dose dobutamine does improve compared with estimates of strain obtained prior to surgery. Future studies should address the time course of recovery of regional function post-CABG and test whether additional interventions might facilitate earlier recovery of contractile reserve.

34 Dissecting transforming growth factor-beta signalling pathways in the context of acute vascular injury

The development of intimal hyperplasia (IH) after coronary artery bypass graft (CABG) surgery significantly reduces the success rate of this procedure. Transforming growth factor-beta (TGFβ) promotes IH; however the underlying signalling mechanisms remain to be fully elucidated. We aimed to perform mechanistic characterisation of the ALK1 and ALK5 TGFβ signalling pathways in the context of vein graft failure. Wound healing and proliferation assays were performed in primary human saphenous vein SMCs (HSVSMC) treated with rTGFβ1 ± small molecule inhibitors of ALK1 (K02288) or ALK5 (SB525334). Although no effect on proliferation was observed, HSVSMC migration was significantly increased in the presence of SB525334, whereas K02288 treatment significantly reduced migration (p

The Effects of Phase III Cardiac Rehabilitation on the Quality of Life of Patients Undergoing Coronary Artery Bypass Graft

Background: Shortage of rehabilitation services as well as personal and financial problems prevents patients from participating in cardiac rehabilitation programs. Participation in these programs alleviates patients’ perceived inadequacy, improves their quality of life, and prolongs their survival. Thus, there is a clear need to educate cardiac patients and guide them toward patient-centered and home-based rehabilitation programs. Objectives: The present study was undertaken to examine the effect of phase III cardiac rehabilitation on the quality of life of patients who had undergone coronary artery bypass graft Methods: This quasi-experimental study was done on forty 35 to 75 year-old patients, who were in phase III cardiac rehabilitation after bypass surgery. Patients were selected purposively and were allocated to a control and an experimental group randomly, 20 patients in each group. The groups did not differ significantly regarding patients’ age, body mass index, and the duration of cardiac problems. A demographic questionnaire and the short form 36 quality of life questionnaire were used for gathering data both before and one month after the study intervention. A cardiac rehabilitation educational program was implemented for the patients in the experimental group with six 1.5-hour sessions in three subsequent weeks. Patients in the control group also received the same education in four sessions, which were held after the posttest. The data were entered in the SPSS (v. 15.0) software and were analyzed by running repeated measure analysis of variance (ANOVA), the paired- and the independent-sample t, the one-way ANOVA, and the Tukey’s post-hoc statistical tests. The level of significance was set at 0.05. Results: The pretest mean score of quality of life in the experimental group was 43.6 ± 13.2, which increased to 56.1 ± 9.4 after the intervention (P < 0.001). The pretest-posttest mean difference of the total quality of life scores in the experimental and the control groups was 12.5 and 4.5. This difference was statistically significant (P < 0.001). Moreover, the scores of all domains of quality of life in the experimental group increased significantly after the study (P < 0.001). Conclusions: The findings of this study showed that phase III (home-based) cardiac rehabilitation has significant effects on the quality of life of patients, who had undergo coronary artery bypass graft. Given the limited implementation of phase II rehabilitation programs in Iranian hospitals, implementing phase III rehabilitation programs can significantly affect patients’ quality of life after bypass graft surgery.

UNIAXIAL AND BIAXIAL MECHANICAL PROPERTIES OF THE HUMAN SAPHENOUS VEIN

Cardiovascular diseases are one of the major causes of death in the world and are closely related to blood dynamics and wall mechanical properties of vessels. This makes the study of mechanical properties of arteries and veins essential. In this regard, study on common vessels used in bypass grafting operations is of special importance due to the frequency of this surgery. Human saphenous vein is one of the vessels used for bypass surgeries. The objective of the present study is to characterize the behavior of human saphenous vein using uniaxial and biaxial planar tests. Forty human saphenous samples were obtained after coronary artery bypass surgery (CABG). The planar tensile tests were performed on the tissue specimens by applying loads along two directions. These tests provided the force-displacement curves. The stress-strain curves from uniaxial tests were modeled with a mathematical function and the Young modulus was obtained in both longitudinal and circumferential directions. Measured data of uniaxial tests were then fitted into a hyperelastic four-parameter Fung-type model and also an isotropic Mooney–Rivlin model. The biaxial stress-stretch curves were fitted to a hyperelastic anisotropic four-parameter Fung-type model and a five-parameter Mooney–Rivlin model. The specimens showed some degrees of anisotropy. In both uniaxial and biaxial tests, specimens showed stiffer behaviour in longitudinal as opposed to circumferential directions. The stretch ratio in the circumferential direction was much higher than in the longitudinal orientation.

TCT-429 Radial versus Femoral Approach for Coronary Angiography and Intervention in Patients with CABG: Systematic Review and Meta-analysis

Cardiac catheterization through the radial approach has been shown to significantly reduce vascular access complications and bleeding, as compared with the femoral approach, in multiple clinical settings. However, in the subset of patients with previous coronary artery bypass graft (CABG) surgery,

Radial Artery Grafts as Rescue Strategy for Patients with Moyamoya Disease for Whom Conventional Revascularization Failed

Failure of direct revascularization with superficial temporal artery (STA)-middle cerebral artery (MCA) bypass for Moyamoya disease (MMD) is comparatively rare. However, for those cases where a bypass fails to prevent further ischemic attacks, safe and efficient rescue strategies are needed. We present our experience with radial artery grafts for secondary revascularization of MMD. Between April 2007 and April 2014, we have performed STA-MCA bypass in 182 patients diagnosed with Moyamoya vasculopathy. Four patients with typical MMD who had an unsuccessful STA-MCA bypass required additional revascularization because they remained symptomatic. Digital subtraction angiography revealed delayed STA graft failure in these patients, who continued to have transient ischemic attacks after the initial surgery. Cerebral blood flow studies confirmed persistent impairment of cerebrovascular reserve capacity. As an escape strategy, we performed radial artery graft bypass surgery from the external carotid artery to the M2 or M3 portion of the MCA. The median duration between the 2 surgeries was 10 months. The mean follow-up period after rescue revascularization was 8.5 ± 3.3 months. Revascularization with the radial artery graft was successful in all cases without perioperative complications. Postoperatively, none of the patients experienced further cerebrovascular events. After 3 months, digital subtraction angiography revealed patent radial artery grafts and adequate revascularization in 3 patients; 1 patient presented with bypass graft failure but had developed transdural collateral vessels contributing to the filling of the cerebral vasculature. Rescue bypass with a radial artery graft provides a useful function. Although delayed graft failure may occur, this procedure is successful if the patients remain symptom free with the development of collateral flow.

Coronary Artery Bypass Grafting in a Patient with Organophosphate Poisoning

A 43-year-old male, with no previous history of mental illness, was diagnosed with coronary heart disease, after which he became acutely depressed and attempted suicide by ingesting an organophosphate pesticide. He was admitted to an intensive care unit and treated with pralidoxime, atropine, and oxygen. His coronary occlusion pattern required early coronary artery bypass grafting (CABG) surgery. His family, apprehensive of a repeat suicidal attempt, requested surgery be performed as soon as possible. He recovered well from the OP poisoning and was mentally fit to express informed consent 2 weeks after admission. Seventeen days after poisoning, he underwent coronary artery bypass grafting and recovered uneventfully. Six years later, he remains in excellent health. We report this case because to the best of our knowledge there is no literature regarding CABG performed soon after organophosphate poisoning.