Initial Coronary Artery Bypass Grafting Research Articles

Coronary artery bypass grafting vs. drug-eluting stent implantation: the probabilities of reintervention, transition to severe care-need, nursing home, and death in patients with coronary artery disease within the first three years: evaluations based on health claims data in Germany.

Coronary artery bypass grafting (CABG) and drug-eluting stent implantation (DES) are established as central methods of revascularization for patients with coronary artery disease. This study aims to analyse the health trajectories of patients after first CABG or first, second or third DES within the first three years, with a focus on follow-up interventions, severe care need, transition into a nursing home, and death. Based on health claims data (n=11,581), we estimated age-and sex standardized probabilities of reintervention, and of transition to severe care need, nursing home and death following initial CABG (n=2,008) or DES (n=9,573) for patients aged 50 years and older using logistic regression models and direct standardization. Up to three follow-up DES interventions and one follow-up CABG were considered. There was a fairly high probability of reintervention, particularly after a DES and within the first year. Follow-up interventions were more likely to involve DES than CABG. The probability of death was notably higher for CABG patients. The probabilities of severe care need and moving to a nursing home were slightly lower and similar across the revascularization methods and over time. DES and CABG are often associated with a need for follow-up interventions. Depending on the procedure, however, the risk of repeat surgery or adverse health outcomes varies. DES is associated with a relatively high probability of follow-up revascularization and a nearly constant probability of negative health outcomes in the short and medium term. In contrast, within three years after a CABG, follow-up reinterventions are rather rare. However, this procedure is particularly associated with an increased risk of mortality and short-term transition into a nursing home.

Percutaneous Coronary Intervention in a Saphenous Vein Graft Failure: A Case Report

Abstract: Recent published data from the Society of Thoracic Surgery (STS) national database displayed that among patients aged >65 years old who survived following an initial coronary artery bypass graft (CABG) operation, rates of repeat revascularization at 1, 5, 10, and 18 years were 2%, 8%, 16%, and 25%, respectively. The most preferred mode of revascularization was percutaneous coronary intervention (PCI). While remain the most frequently used conduits beside left internal mammary artery (LIMA), saphenous vein grafts (SVGs) have high failure rates. Percutaneous coronary intervention in SVGs is associated with an increased risk of distal coronary embolization, commonly resulting in periprocedural MI. We reported a 79-year-old male patient admitted due to progressive symptoms of chronic coronary syndrome. The patient had a history of hypertension and a CABG surgery in 2012. Electrocardiogram showed ischemia and old myocardial infarction (OMI) in inferior leads as well as poor R wave progression in the precordial leads. Transthoracic echocardiogram displayed a normal ejection fraction but impaired left ventricular (LV) diastolic relaxation. Diagnostic coronary angiography revealed a 70% tubular stenosis in proximal part of SVG supplying posterior descending artery, patent LIMA graft to left anterior descending artery, and complex lesion on native vessel (chronic total occlusion in mid right coronary artery). Implantation of drug eluting stent in SVG-posterior descending artery was performed. Direct-stenting PCI technique using undersized-stent was done to prevent any complications. In conclusion, despite the high risk of complications, vein graft intervention was successfully performed without any complications. Since the high rates of in-stent restenosis following PCI in SVGs, long-term dual antiplatelet therapy should be commenced in this patient. Keywords: saphenous vein graft; vein graft intervention; percutaneous coronary intervention

Impact of repeat revascularization within 5 years on 10-year mortality after percutaneous or surgical revascularization

Abstract Background The SYNTAX trial demonstrated negative impact of repeat revascularization (RR) on 5-year outcomes following percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) in patients with three-vessel (3VD) and/or left main coronary artery disease (LMCAD). We aimed to investigate the impact of RR within 5 years, on 10-year mortality in patients with 3VD and/or LMCAD after PCI or CABG. Methods The SYNTAXES study evaluated the vital status out to 10 years of patients with 3VD and/or LMCAD. Patients were stratified by RR within 5 years and randomized treatment. The association between RR within 5 years and 10-year mortality was assessed. Results A total of 330 (220 RR after initial PCI and 110 RR after initial CABG) out of 1800 patients (18.3%) underwent RR within 5 years from initial revascularization. RR occurred more frequently after initial PCI than after initial CABG (25.9% vs 13.7%, p<0.001). Overall, 10-year mortality was comparable between patients undergoing RR and those not (28.2% vs 26.1%, adjusted HR: 1.17, 95% CI: 0.93-1.48, p=0.187). Among patients requiring RR, those who underwent PCI as initial revascularization had a higher risk of 10-year mortality compared to initial CABG (33.5% vs 17.6%, adjusted HR: 2.09, 95% CI: 1.21-3.61, p=0.008). Conclusions In the SYNTAXES study, RR within 5 years had no impact on 10-year all-cause death in the population overall. Among patients requiring any repeat procedures, 10-year mortality was higher after initial treatment with PCI than after CABG. These exploratory findings should be investigated with larger populations in future studies.Graphic Abstract

Therapeutic Strategies and Future Directions of Management for Patients with a History of Coronary Artery Bypass Grafting Who Require Secondary Coronary Revascularization

Secondary coronary revascularizations can be required due to the progression of coronary artery lesions and degeneration of bypass grafts in the long term after initial coronary artery bypass graft (CABG) surgery. It is therefore necessary to clarify the clinical characteristics of these patients and how to improve their prognosis. Optimal medical treatments, including medications, smoking cessation, and cardiac rehabilitation, are essential baseline management to prevent the progression of native coronary atherosclerosis and degradation of bypass grafts among all post-CABG patients who undergo secondary coronary revascularization as well as those who undergo initial CABG surgery in order to avoid situations requiring secondary coronary revascularization. All coronary revascularization procedures should be built upon these firm optimal medical treatments. Percutaneous coronary intervention is the current mainstay of secondary coronary revascularization approaches for patients who have symptoms of heart failure or angina pectoris because of the low invasiveness of the technique and no need for re-sternotomy. Redo-CABG is an option, especially for young patients without patency for internal thoracic artery to left anterior descending artery graft. The individualization of these approaches and improvements in medications and coronary revascularization procedures may improve the clinical outcomes and prognosis of this subgroup.

Bilateral Internal Thoracic Artery Grafting Improves Survival for Severe Left Ventricular Dysfunction and Diabetes.

In patients with severe left ventricular (LV) dysfunction requiring coronary artery bypass grafting (CABG), the association between diabetic status and outcomes after surgery, as well as with survival benefit following bilateral internal thoracic artery (ITA) grafting, remain largely unknown. Patients (n=188; mean [±SD] age 67±9 years) with LV ejection fraction ≤40% who underwent isolated initial CABG were classified into non-diabetic (n=64), non-insulin-dependent diabetic (NIDM; n=74), and insulin-dependent diabetic (IDM; n=50) groups. During follow-up (mean [±SD] 68±47 months), the 5-year survival rate was 84% and 65% among non-diabetic and diabetic patients, respectively (P=0.034). After adjusting for all covariates, both NIDM and IDM were associated with increased mortality, with hazard ratios (HRs) of 1.9 (95% confidence interval [CI] 1.0-3.7; P=0.049) and 2.4 (95% CI 1.2-4.8; P=0.016), respectively. Among non-diabetic patients, there was no difference in the 5-year survival rate between single and bilateral ITA grafting (86% vs. 80%, respectively; P=0.95), whereas bilateral ITA grafting increased survival among diabetic patients (57% vs. 81%; P=0.004). Multivariate analysis revealed that bilateral ITA was significantly associated with a decreased risk of mortality (HR 0.3; 95% CI 0.1-0.8; P=0.024). NIDM and IDM were significantly associated with worse long-term clinical outcome after CABG for severe LV dysfunction. Bilateral ITA grafting has the potential to improve survival in diabetic patients with severe LV dysfunction.

Repeat revascularization impact on 10-year survival after PCI or CABG: post-hoc analysis of the SYNTAXES trial

Abstract Background Available data comparing Percutaneous Coronary Interventions (PCI) and Coronary Artery Bypass Graft (CABG) in multivessel or left main coronary artery disease (CAD) suggest higher rates of repeat revascularization events after PCI than CABG, with a negative influence on outcomes up to 5 years. The impact of repeat revascularization on very long-term outcomes remains unclear. Aims This study aims to investigate the impact on 10-year all-cause death of repeat revascularizations in patients with three-vessel disease (3VD) and/or left main coronary artery disease (LMCAD). Methods The SYNTAXES study evaluated the vital status out to 10-year of patients with 3VD and/or LMCAD enrolled in the SYNTAX trial. Repeat revascularization events occurred within the first 5 years from the index procedure were adjudicated by an independent clinical events committee. Effects of repeat revascularizations on 10-year all-cause death were investigated through time-dependent Cox regression analysis. Results During the first 5 years, 330 out of 1800 patients (18.3%) underwent a minimum of one repeat revascularization, for a total of 459 repeat revascularization procedures, mostly consisting of repeat-PCI (393, 85.6%). Repeat revascularizations were more frequent among patients initially randomized to PCI (HR 2.3, 95% CI: 1.8–3.0, p<0.0001). At 10 years, all-cause death was comparable between patients underwent any repeat revascularization and those not (27.6% vs. 25.1%, adjusted HR 2.3, 95% CI: 0.8–6.2, p=0.11). However, among patients requiring repeat revascularizations, who underwent initial PCI versus initial CABG presented a significantly higher 10-year all-cause death (32.7% vs 17.3%, p=0.004). The adjusted risk for 10-year all-cause death according to the subtypes of repeat revascularizations revealed only revascularization with CABG was an independent predictor (HR 6.2, 95% CI: 1.5–25.2, p=0.011). Conclusions In the SYNTAX trial, repeat revascularizations were more frequent after initial PCI. Although no difference on 10-year all-cause death was observed between patients who did undergo repeat revascularizations and who did not, higher death rates were reported among those required any repeat procedures after initial PCI or revascularization with CABG. These exploratory findings should be investigated with larger population in future studies. Funding Acknowledgement Type of funding sources: None. Survival curves at 10-year follow-up

P4586Bilateral internal thoracic artery grafting neutralizes detrimental effect of diabetes on survival in patients with ischemic cardiomyopathy

Abstract Background In ischemic cardiomyopathy patients requiring coronary artery bypass grafting (CABG), the association of diabetic status with outcomes after surgery as well as survival benefit with bilateral internal thoracic artery (ITA) grafting remain largely unknown. Purpose We evaluated the associations of diabetic status with postoperative LV reverse remodeling, change in renal function, and late outcome following surgical revascularization, with focus on cases with severely impaired LV function. We also attempted to determine the survival benefit of bilateral ITA grafting over single ITA grafting according to diabetic status. Methods We classified 188 patients (mean age 67±9 years) with left ventricular (LV) ejection fraction ≤40% who underwent isolated initial CABG into non-diabetic (n=64), non-insulin-dependent DM (NIDM, n=74), and insulin-dependent DM (IDM, n=50) groups. Results At baseline, there were no differences between the diabetic and non-diabetic patients in terms of age, LV function parameters and degree of coronary artery disease, while the diabetic patients were more likely to present chronic kidney disease and peripheral vascular disease. During follow-up (68±47 months), the 5-year survival rate was 84% and 65% in the non-diabetic and diabetic patients respectively (p=0.034). After adjusting for all covariates, both NIDM and IDM were independently associated with increased mortality (NIDM: adjusted hazard ratio 1.9, 95% confident interval 1.0–3.7, p=0.049; IDM: adjusted hazard ratio 2.4, 95% confident interval 1.2–4.8, p=0.016) and composite adverse events defined as mortality and/or heart failure readmission (NIDM: hazard ratio 1.7, 95% confident interval 1.0–2.8, p=0.038; IDM: hazard ratio 3.0, 95% confident interval 1.7–5.1, p<0.001). Diabetic patients showed less improvements in LV dimensions and ejection fraction (interaction effect p<0.05 for all), and steady decrease in the estimated glomerular filtration rate over time after surgery (group effect p<0.05). Among non-diabetic patients, there was no difference in survival rate between single ITA and bilateral ITA grafting (5-year: 86% vs. 80%, p=0.95), whereas among diabetic patients, survival of those who received the latter was better (57% vs. 81%, p=0.004). Multivariate analysis revealed that use of bilateral ITA was significantly associated with decreased risk of mortality (hazard ratio 0.3, 95% confident interval 0.1–0.8, p=0.024). Conclusion Non-insulin- and insulin-dependent diabetes was significantly associated with worse long-term clinical outcome after CABG for ischemic cardiomyopathy. Bilateral ITA grafting has potential to improve survival in diabetic patients with ischemic cardiomyopathy.

Management of a Case of Severe Coronary Subclavian Steal Syndrome Twenty Years Post-Coronary Artery Bypass Graft in a Patient who Presented With Acute Myocardial Infarction

The efficacy, safety, and long-term success of using the left internal mammary artery (LIMA) to bypass the left anterior descending artery (LAD) is well-established and is the most frequently used conduit for coronary artery bypass grafting (CABG) [ [1] Cua B. et al. Review of coronary subclavian steal syndrome. J Cardiol. 2017; 70: 432-437 Abstract Full Text Full Text PDF PubMed Scopus (28) Google Scholar ]. A left subclavian artery origin stenosis may progress enough to cause retrograde flow or ‘stealing’ of the myocardial blood supply via the LIMA graft to maintain left upper limb perfusion. This is known as Coronary Subclavian Steal Syndrome (CSSS) and its prevalence is likely underestimated [ [1] Cua B. et al. Review of coronary subclavian steal syndrome. J Cardiol. 2017; 70: 432-437 Abstract Full Text Full Text PDF PubMed Scopus (28) Google Scholar ]. This study described the successful management of a 72-year-old male with severe CSSS who presented with an acute myocardial infarction (AMI) 20 years following initial CABG. There is a lack of formal screening for left subclavian artery stenoses in both preoperative and postoperative CABG patients [ [1] Cua B. et al. Review of coronary subclavian steal syndrome. J Cardiol. 2017; 70: 432-437 Abstract Full Text Full Text PDF PubMed Scopus (28) Google Scholar ]. There is also a lack of consensus for intervention in this condition, with some sufferers of CSSS successfully managed conservatively [ [2] Angle J.F. et al. Percutaneous angioplasty and stenting of left subclavian artery stenosis in patients with left internal mammary-coronary bypass grafts: clinical experience and long-term follow-up. Vasc Endovasc Surg. 2003; 37: 89-97 Google Scholar ]. During coronary angiography, pressure-gradient measurements in one study showed a mean pre-treatment gradient of 29 mmHg [ [2] Angle J.F. et al. Percutaneous angioplasty and stenting of left subclavian artery stenosis in patients with left internal mammary-coronary bypass grafts: clinical experience and long-term follow-up. Vasc Endovasc Surg. 2003; 37: 89-97 Google Scholar ]. In this case, the patient had a pre-treatment gradient of 65 mmHg and left ventricular wall motion abnormalities. He received left subclavian artery stenting and was discharged on postoperative day 1, at which time he had a palpable radial pulse, he had no further myocardial infarctions.

Redo coronary bypass grafting for congenital left main coronary atresia: a case report

BackgroundCongenital left main coronary atresia is an extremely rare coronary anomaly. Long-term surgical outcomes and the optimal management strategies for recurrence of ischemia remain uncertain. Herein, we present a case involving successful redo coronary artery bypass grafting for unstable angina 27 years after the initial coronary artery bypass grafting for congenital left main coronary atresia.Case presentationA 33-year-old woman was referred to our department with unstable angina. At the age of 6, she had undergone coronary artery bypass grafting of the second diagonal branch using the left internal thoracic artery and the obtuse marginal branch using saphenous vein grafting for left main coronary atresia. Although a coronary angiogram showed a patent left internal thoracic artery graft to the second diagonal branch and a patent saphenous vein graft to the obtuse marginal branch, the left anterior descending artery was not being perfused by the grafts because of a disruption of blood flow to the left anterior descending artery from the left internal thoracic artery. Therefore, we performed a redo coronary artery bypass grafting using the in situ right internal thoracic artery to the first diagonal branch, which was to be connected to the left anterior descending artery, resulting in amelioration of the ischemia of the left anterior wall. The patient was discharged 10 days after the operation and has been in good health for over 3 years without recurrence of chest symptoms.ConclusionsCoronary revascularization using a saphenous vein and left internal thoracic artery grafts is effective in achieving an adequate blood supply to the distal coronary arteries, and this effect can last for decades. However, careful follow-up is necessary because recurrent myocardial ischemia due to the development of a coronary artery occlusion may occur in adulthood.

Impact of diabetes duration on 3-year clinical outcomes following coronary revascularization.

The aim of this study was to evaluate the impact of diabetes duration on long-term clinical outcomes after drug-eluting stent (DES) implantation or coronary artery bypass grafting (CABG). A total of 820 diabetic patients treated with initial DES (n=451) or CABG (n=369) were consecutively enrolled in this single-center follow-up study. The main outcomes included major adverse cardiac events and major adverse cardiac or cerebrovascular events (MACCEs). Cox regression analysis with propensity adjustment was used for data analysis. Three-year risks of major adverse cardiac events were significantly higher in the DES group compared with the CABG group irrespective of whether the diabetes durations were less or more than 5 years [hazard ratio (HR) 2.27, 95% confidence interval (CI) 1.19-4.31, P=0.01; HR 3.73, 95% CI 2.72-10.12, P<0.01; P for interaction=0.28]. A similar trend was observed for repeat revascularization. However, CABG was associated with increased risk of stroke, especially in the patients with diabetes duration of at least 5 years (HR 0.02, 95% CI 0.002-0.12, P<0.01). Three-year risk of MACCEs was significantly higher in the DES group in patients with diabetes duration of at least 5 years (HR 2.13, 95% CI 1.34-3.39, P<0.01), but not for those less than 5 years (HR 1.03, 95% CI 0.65-1.63, P=0.91). A statistically significant interaction between diabetes duration and treatment strategy was found for MACCEs (P for interaction=0.04). Short diabetes duration (<5 years) was associated with equal risk of MACCEs among stable coronary artery disease patients with DES and CABG, emphasizing the need to consider the duration of diabetes when determining the best strategy for patients undergoing coronary revascularization.

ACUTE MYOCARDIAL INFARCTION TREATED WITH PRIMARY PERCUTANEOUS CORONARY INTERVENTION IN PATIENTS WITH PRIOR CORONARY ARTERY BYPASS GRAFTING AT A SINGLE CENTRE IN CANADA

Due to an aging population, there is an increase in the number of patients undergoing coronary artery bypass grafting (CABG) presenting with ST-segment elevation myocardial infarction (STEMI). Despite this, there is a lack of data in this high-risk patient population. The purpose of the study is to characterize the baseline characteristics, culprit lesions and outcomes of patients with previous CABG and STEMI. We retrospectively reviewed a database of all patients undergoing emergency percutaneous coronary intervention (PCI) of which 95.8% of patients had electrocardiographic evidence of STEMI at a single-centre in British Columbia between January 2009 and December 2013. There were 94 (2.9%) patients with a prior history of CABG in a total of 3231 patients. The prior CABG group was significantly older and had a significantly greater incidence of hypertension, dyslipidemia, diabetes, previous MI, previous heart failure, and previous PCI. There was a significantly greater length of stay in the CABG population, but no difference when comparing in hospital mortality. The infarct-related vessel in the CABG group was a bypass graft in 44 patients (48.9%), native coronary artery in 36 patients (40.0%), was not identifiable in 10 patients (11.1%) and 4 patients had missing data. We further stratified previous CABG patients by the time between emergency PCI and index CABG. There were 79 patients (84.0%) who had CABG more than five years from emergency PCI. There were no significant differences in baseline characteristics, culprit lesions and 30-day mortality between CABG more than five years and less than five years from emergency PCI. Emergency PCI for STEMI after previous CABG is associated with more comorbidities when compared with patients that did not undergo previous CABG. However, there were similar outcomes in short-term mortality. Furthermore, there were no significant differences in baseline characteristics and short-term mortality between the timing from initial CABG to emergency PCI. Further data analysis is needed to characterize longer-term outcomes.

Dual Protection Therapy with Staged Coronary Artery Bypass Surgery and Stenting in Patients with Left Main Coronary Artery Stenosis: Long-Term Results from a Single Center

We evaluated the efficacy and safety of dual protection therapy with staged coronary artery bypass grafting (CABG) and bare-metal stenting (BMS) in patients with left main coronary artery (LMCA) disease. CABG is currently the preferred therapy for complex LMCA disease; however, the long-term patency rates of these grafts are unsatisfactory, and stenting alone for LMCA may be associated with the potentially fatal consequences of stent thrombosis or restenosis. Between January 1997 and October 2005, 42 patients underwent staged bypass surgery and BMS, with the latter procedure performed 2 weeks after the initial CABG. Of these patients, 40 received left internal mammary artery (LIMA) grafts, 34 saphenous vein grafts, 6 radial artery grafts, and 3 right IMA (RIMA) grafts. Minimally invasive bypass surgery was performed in 10 patients. There were no operative complications. Forty-two stents were implanted in 42 lesions without complications. During the follow-up period of 135 ± 55 months, 1 patient died of cancer, 2 of cardiac causes, and 5 patients (12%) experienced target lesion revascularization. The target vessel failure rate was 24%. Forty patients (95%) underwent a 6-month angiographic follow-up. Restenosis was noted in 7 patients (18%). Reocclusion was also noted in 5 LIMA grafts, 5 saphenous vein grafts, 1 radial artery graft, and 1 RIMA graft. Only 1 patient experienced both restenosis of LM stenting and total occlusion of the 2 bypass grafts. Dual protection therapy with staged CABG and stenting is not an appropriate therapeutic strategy because of unacceptable graft patency rate. A higher occlusive rate of the bypass grafts may result from decreased blood flow because of competing blood flow between the bypass graft and the native coronary vessel.

Clinical Features, Management, and Prognosis of Spontaneous Coronary Artery Dissection

Spontaneous coronary artery dissection (SCAD) is an acute coronary event of uncertain origin. Clinical features and prognosis remain insufficiently characterized. A retrospective single-center cohort study identified 87 patients with angiographically confirmed SCAD. Incidence, clinical characteristics, treatment modalities, in-hospital outcomes, and long-term risk of SCAD recurrence or major adverse cardiac events were evaluated. Mean age was 42.6 years; 82% were female. Extreme exertion at SCAD onset was more frequent in men (7 of 16 versus 2 of 71; P<0.001), and postpartum status was observed in 13 of 71 women (18%). Presentation was ST-elevation myocardial infarction in 49%. Multivessel SCAD was found in 23%. Initial conservative management (31 of 87) and coronary artery bypass grafting (7 of 87) were associated with an uncomplicated in-hospital course, whereas percutaneous coronary intervention was complicated by technical failure in 15 of 43 patients (35%) and 1 death. During a median follow-up of 47 months (interquartile range, 18-106 months), SCAD recurred in 15 patients, all female. Estimated 10-year rate of major adverse cardiac events (death, heart failure, myocardial infarction, and SCAD recurrence) was 47%. Fibromuscular dysplasia of the iliac artery was identified incidentally in 8 of 16 femoral angiograms (50%) undertaken before closure device placement and in the carotid arteries of 2 others with carotid dissection. SCAD affects a young, predominantly female population, frequently presenting as ST-elevation myocardial infarction. Although in-hospital mortality is low regardless of initial treatment, percutaneous coronary intervention is associated with high rates of complication. Risks of SCAD recurrence and major adverse cardiac events in the long term emphasize the need for close follow-up. Fibromuscular dysplasia is a novel association and potentially causative factor.

Debate over patient-centered care: Percutaneous coronary intervention or coronary artery bypass grafting?

Coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) have developed as effective therapies to treat coronary artery disease. Initial CABG is associated with lower mortality than initial medical management, especially among high- and intermediate-risk patients with coronary artery disease. However, PCI is currently the most frequent initial treatment delivered by interventional cardiologists to treat multivessel coronary artery disease, despite substantial evidence from meta-analyses of randomized trials and registry data favoring CABG. Recent advancements in PCI did not result in detectable improvements in death or myocardial infarction compared with medical therapy, although significant reductions in target lesions or vessel revascularization were identified after implantation of a drug-eluting stent (DES) rather than a bare-metal stent. The SYNTAX trial compared patients with left main and/or three-vessel coronary artery disease treated with DES or CABG. The results of the trial demonstrated the 1-year inferiority of PCI compared with CABG with respect to major adverse cardiac and cerebrovascular events. Nevertheless, patients with coronary artery disease continue to receive more recommendations for PCI and fewer for CABG than are indicated in the guidelines. A multidisciplinary team approach should be the standard of care when recommending interventions for treating complex coronary artery disease among patients for whom CABG is superior in terms of survival and freedom from reintervention.

Intrapericardial Diaphragmatic Hernia after Coronary Artery Bypass Grafting Using the Right Gastroepiploic Artery Graft: Report of a Case

Surgeons should be aware of diaphragmatic hernia in obese patients who have undergone coronary artery bypass grafting (CABG) using a gastroepiploic artery graft (GEA), even if the antegastric route is utilized.We report a case of diaphragmatic hernia, which occurred 88 months after initial CABG. A 64-year-old obese man underwent surgical repair of a diaphragmatic hernia. At initial surgery, the diaphragm was incised vertically and re-sutured, leaving a route for GEA graft. Both the stomach and the lateral segment of the liver were dislocated in the pericardial space. The diaphragmatic defect was closed with a polytetrafluoroethylene patch.

The relation between blood and tissue magnesium levels and development of atrial fibrillation after coronary artery bypass surgery

Atrial fibrillation (AF) is a common complication of cardiovascular surgery and its mechanisms are not well understood. The aim of our study was a prospective investigation of the relationship between AF development and tissue or blood magnesium levels. This prospective observational study evaluated 20 patients undergoing elective initial coronary artery bypass graft (CABG) surgery. Right atrial appendage and skeletal muscle samples were obtained for tissue magnesium level analysis before, during (at 60th minute) and 30 minutes after cardiopulmonary bypass (CPB) with simultaneous blood samples. Daily measurements of blood Mg levels and continuous monitoring for AF were performed for 7 postoperative days. Statistical analyses were performed using ANOVA, independent samples t and Chi-square tests. AF developed in 5 out of 20 patients during postoperative period (25%). Patients with or without AF did not differ in terms of tissue and blood magnesium levels during and early after CPB and during 7 days after the operation. Blood magnesium levels were significantly higher in the whole study population on postoperative days 3 through 7 (day 3 - 1.13±0.11 mmol/L; day 4-, 1.18±0.07 mmol/L; day 5-1.15±0.10 mmol/L; day 6-1.17±0.08 mmol/L; and day 7, 1.22±0.08 mmol/L) compared to day 1 and day 2 (day 1-0.96±0.13 mmol/L and day 2-1.02±0.12 mmol/L; p=0.002 for all comparisons). Although patients with and without AF did not significantly differ with regard to blood and tissue magnesium levels, the coincidence of an early postoperative reduction in magnesium levels in all patients and occurrence of all AF incidences at this time period suggests a potential association deserving further investigation.

Difference in Patient Profiles and Outcomes in Japanese Versus American Patients Undergoing Coronary Revascularization (Collaborative Study by CREDO-Kyoto and the Texas Heart Institute Research Database)

Although coronary revascularization is common in both Japan and the United States (US), no direct comparison has been performed to demonstrate differences in the clinical characteristics and long-term outcomes of patients in these 2 countries. We analyzed the preprocedural, in-hospital, and long-term data from the Coronary Revascularization Demonstrating Outcome registry (Kyoto, Japan) and the Texas Heart Institute Research Database (Houston, Texas) of 16,100 patients who had undergone elective, initial percutaneous coronary intervention or coronary artery bypass grafting. The Japanese procedures were performed from 2000 to 2002 (n = 8,871, follow-up period 3.5 years, interquartile range 2.6 to 4.3) and the US procedures from 1999 to 2003 (n = 7,229, follow-up period 5.2 years, interquartile range 3.8 to 6.5). The Japanese patients tended to be older (mean age 67.2 vs 62.7 years; p <0.001), to smoke (52.9% vs 46.0%; p <0.001), and to have diabetes (39.2% vs 31.0%; p <0.001) and stroke (16.4% vs 5.0%; p <0.001). The US patients were more obese (body mass index 23.7 vs 29.3 kg/m(2); p <0.001), with greater rates of systemic atherosclerotic disease. Both groups had a similar in-hospital mortality rate (Japanese patients 0.9% vs US patients 1.1%; p = 0.19) and crude long-term mortality rate (Japanese patients 27.7/1,000 person-years, US patients 28.2/1,000 person-years; p = 0.35). After adjustment for known predictors, the US group had greater long-term mortality than the Japanese group (hazard ratio 1.71, 95% confidence interval 1.50 to 1.95; p <0.001). This finding was consistent among all high-risk subgroups. In conclusion, the 2 registries showed similar crude outcomes but important differences in patient risk factors such as obesity. In the adjusted analysis, the Japanese patients had better outcomes than did the US patients. Additional study is needed to assess the effect of ethnic and risk factor variations on coronary artery disease.

Late outcomes after radial artery versus saphenous vein grafting during reoperative coronary artery bypass surgery

We investigated whether use of radial artery versus saphenous vein grafts during coronary artery bypass grafting reoperations is associated with a significant long-term survival benefit. We reviewed a series of 347 consecutive coronary artery bypass grafting reoperations (1996-2007; 270 [78%] male patients; age, 65.3 +/- 9.2 years). Internal thoracic artery grafts were used in 248 (71%) patients at the time of the first coronary artery bypass grafting operation and in 154 (44%) patients at reoperation. Patients were grouped based on whether a functional radial artery graft was present after coronary artery bypass grafting reoperation (radial artery cohort, n = 203 [59%]) or not (saphenous vein cohort, n = 144 [41%]). Median time to reoperation was similar for the radial artery (10.3 years) and saphenous vein (10.1 years) cohorts (P = .55). Angiographic data were used to ascertain the number and type of grafts that remained functional from initial coronary artery bypass grafting. Survival data (< or = 12 years) were time segmented based on multiphase hazard modeling at 90 days, and late survival was then analyzed by using proportional hazard Cox regression, with risk adjustment based on a radial artery-use propensity score computed from 48 covariates, including time to reoperation, month of surgical intervention, and total arterial and vein grafts after reoperation. Propensity-matched and propensity quintile comparisons were also done. Follow-up was similar for the radial artery versus saphenous vein cohorts (5.7 +/- 3.4 vs 5.8 +/- 4.0 years, P = .86), and 112 (50 in the radial artery and 62 in the saphenous vein cohorts) deaths were documented. Early mortality (< or = 90 days) did not differ for the radial artery (7.4%) and saphenous vein (12.5%) cohorts (P = .14). Unadjusted late outcomes were superior for the radial artery versus saphenous vein cohorts, with survival of 97.3% versus 92.9%, 84.9% versus 77.2%, and 74.1% versus 60.3% at 1, 5, and 10 years, respectively. Propensity-adjusted radial artery survival was superior, with a hazard ratio of 0.58 (P = .04), and this result was confirmed in a propensity-matched comparison. We conclude that the use of radial artery as opposed to saphenous vein grafting for reoperative coronary artery bypass grafting, either with or without concomitant internal thoracic artery grafts, is associated with a substantial improvement in late survival. This benefit is likely derived from the increased overall number of arterial grafts.

Repeat intervention after invasive treatment of coronary arteries☆

Patients who undergo successful revascularisation either with coronary artery bypass grafting (CABG) or with percutaneous coronary intervention (PCI) may subsequently require repeat invasive procedures. A cohort of 662 coronary artery diseased (CAD) patients was retrospectively reviewed. Follow-up was 36 months. Thirty-day mortality was 1.0% in the CABG group (n=302) and 0% in the PCI group (n=360) (p=0.094). Overall 3-year survival for the cohort was 95.0% (NS). In addition to repeat angiographies (cumulative frequency 57.7% for PCI vs 4.3% for CABG, p<0.001) patients underwent both repeat PCI (20.7% vs 3.2%, p<0.001) and repeat CABG (6.9% vs 0.7%, p<0.001) during the follow-up. In Cox regression analysis hazard ratio (HR) for repeat PCI after initial PCI was 8.5, 95% confidence interval (CI) 3.7-19.5, p<0.001 and for repeat CABG 9.5, CI 2.2-40.0, p=0.002 in comparison to initial CABG. In-stent restenosis and progression of atherosclerotic plaques in native vessels were reasons for repeat intervention among the PCI patients. Complications with bypass grafts together with progression of the underlying disease were factors for re-interventions after CABG. PCI is far less invasive and may have lower in-hospital mortality rates than CABG. However, the highly likely need for repeat invasive procedures and revascularisation has to be taken into consideration when choosing an invasive approach for multi vessel CAD patients.

Increased Antiangiogenic Protein Expression in the Skeletal Muscle of Diabetic Swine and Patients

Antiangiogenic protein expression is increased in skeletal muscle in the setting of diabetes. In animal studies, diabetes was induced in 8 Yucatan miniswine via single alloxan injection at age 8 months, followed by skeletal muscle harvest 15 weeks later. Eight nondiabetic Yucatan miniswine served as controls. In patient studies, skeletal muscle was harvested from 11 nondiabetic patients and 10 patients with type 2 diabetes mellitus undergoing initial elective coronary artery bypass graft surgery. Skeletal muscle samples were analyzed via Western blotting and zymography for protein expression and enzyme activity. The study was performed in an academic medical center. Skeletal muscle expression of plasminogen, collagen XVIII, angiostatin, endostatin, matrix metalloproteinases 2 and 9, and tissue inhibitor of metalloproteinase 2. Skeletal muscle expression of plasminogen and collagen XVIII (precursors of angiostatin and endostatin, respectively) remained similar between nondiabetic and diabetic swine and patients. Expression of angiostatin and endostatin was increased 1.70-fold and 1.84-fold, respectively, in diabetic swine relative to control swine. Endostatin expression was increased 1.69-fold in diabetic patients relative to nondiabetic patients. Matrix metalloproteinase 2 expression and activity were significantly increased in the skeletal muscle of diabetic swine and patients. Antiangiogenic protein levels are increased in the skeletal muscle in the setting of diabetes. Angiostatin, endostatin, and matrix metalloproteinases may offer novel therapeutic targets to improve collateral formation in patients with diabetes.