Bilateral versus Single Internal-Thoracic-Artery Grafts at 10 Years.

BACKGROUND: Multiple arterial grafts may result in longer survival than single arterial grafts after coronary-artery bypass grafting (CABG) surgery. We evaluated the use of bilateral internal-thoracic-artery grafts for CABG. METHODS: We randomly assigned patients scheduled for CABG to undergo bilateral or single internal-thoracic-artery grafting. Additional arterial or vein grafts were used as indicated. The primary outcome was death from any cause at 10 years. The composite of death from any cause, myocardial infarction, or stroke was a secondary outcome. RESULTS: A total of 1548 patients were randomly assigned to undergo bilateral internal-thoracic-artery grafting (the bilateral-graft group) and 1554 to undergo single internal-thoracic-artery grafting (the single-graft group). In the bilateral-graft group, 13.9% of the patients received only a single internal-thoracic-artery graft, and in the single-graft group, 21.8% of the patients also received a radial-artery graft. Vital status was not known for 2.3% of the patients at 10 years. In the intention-to-treat analysis at 10 years, there were 315 deaths (20.3% of the patients) in the bilateral-graft group and 329 deaths (21.2%) in the single-graft group (hazard ratio, 0.96; 95% confidence interval [CI], 0.82 to 1.12; P=0.62). Regarding the composite outcome of death, myocardial infarction, or stroke, there were 385 patients (24.9%) with an event in the bilateral-graft group and 425 patients (27.3%) with an event in the single-graft group (hazard ratio, 0.90; 95% CI, 0.79 to 1.03). CONCLUSIONS: Among patients who were scheduled for CABG and had been randomly assigned to undergo bilateral or single internal-thoracic-artery grafting, there was no significant between-group difference in the rate of death from any cause at 10 years in the intention-to-treat analysis. Further studies are needed to determine whether multiple arterial grafts provide better outcomes than a single internal-thoracic-artery graft. (Funded by the British Heath Foundation and others; Current Controlled Trials number, ISRCTN46552265 .).

Long-Term Results of the RAPCO Trials.

BACKGROUND: An internal thoracic artery graft to the left anterior descending artery is standard in coronary bypass surgery, but controversy exists on the best second conduit. The RAPCO trials (Radial Artery Patency and Clinical Outcomes) were designed to compare the long-term patency of the radial artery (RA) with that of the right internal thoracic artery (RITA) and the saphenous vein (SV). METHODS: In RAPCO-RITA (the RITA versus RA arm of the RAPCO trial), 394 patients <70 years of age (or <60 years of age if they had diabetes mellitus) were randomized to receive RA or free RITA graft on the second most important coronary target. In RAPCO-SV (the SV versus RA arm of the RAPCO trial), 225 patients ≥70 years of age (or ≥60 years of age if they had diabetes mellitus) were randomized to receive RA or SV graft. The primary outcome was 10-year graft failure. Long-term mortality was a nonpowered coprimary end point. The main analysis was by intention to treat. RESULTS: In the RA versus RITA comparison, the estimated 10-year patency was 89% for RA versus 80% for free RITA (hazard ratio for graft failure, 0.45 [95% CI, 0.23-0.88]). Ten-year patient survival estimate was 90.9% in the RA arm versus 83.7% in the RITA arm (hazard ratio for mortality, 0.53 [95% CI, 0.30-0.95]). In the RA versus SV comparison, the estimated 10-year patency was 85% for the RA versus 71% for the SV (hazard ratio for graft failure, 0.40 [95% CI, 0.15-1.00]), and 10-year patient survival estimate was 72.6% for the RA group versus 65.2% for the SV group (hazard ratio for mortality, 0.76 [95% CI, 0.47-1.22]). CONCLUSIONS: The 10-year patency rate of the RA is significantly higher than that of the free RITA and better than that of the SV. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT00475488.

Radial-Artery or Saphenous-Vein Grafts in Coronary-Artery Bypass Surgery.

BACKGROUND: The use of radial-artery grafts for coronary-artery bypass grafting (CABG) may result in better postoperative outcomes than the use of saphenous-vein grafts. However, randomized, controlled trials comparing radial-artery grafts and saphenous-vein grafts have been individually underpowered to detect differences in clinical outcomes. We performed a patient-level combined analysis of randomized, controlled trials to compare radial-artery grafts and saphenous-vein grafts for CABG. METHODS: Six trials were identified. The primary outcome was a composite of death, myocardial infarction, or repeat revascularization. The secondary outcome was graft patency on follow-up angiography. Mixed-effects Cox regression models were used to estimate the treatment effect on the outcomes. RESULTS: A total of 1036 patients were included in the analysis (534 patients with radial-artery grafts and 502 patients with saphenous-vein grafts). After a mean (±SD) follow-up time of 60±30 months, the incidence of adverse cardiac events was significantly lower in association with radial-artery grafts than with saphenous-vein grafts (hazard ratio, 0.67; 95% confidence interval [CI], 0.49 to 0.90; P=0.01). At follow-up angiography (mean follow-up, 50±30 months), the use of radial-artery grafts was also associated with a significantly lower risk of occlusion (hazard ratio, 0.44; 95% CI, 0.28 to 0.70; P<0.001). As compared with the use of saphenous-vein grafts, the use of radial-artery grafts was associated with a nominally lower incidence of myocardial infarction (hazard ratio, 0.72; 95% CI, 0.53 to 0.99; P=0.04) and a lower incidence of repeat revascularization (hazard ratio, 0.50; 95% CI, 0.40 to 0.63; P<0.001) but not a lower incidence of death from any cause (hazard ratio, 0.90; 95% CI, 0.59 to 1.41; P=0.68). CONCLUSIONS: As compared with the use of saphenous-vein grafts, the use of radial-artery grafts for CABG resulted in a lower rate of adverse cardiac events and a higher rate of patency at 5 years of follow-up. (Funded by Weill Cornell Medicine and others.).

Association of Radial Artery Graft vs Saphenous Vein Graft With Long-term Cardiovascular Outcomes Among Patients Undergoing Coronary Artery Bypass Grafting: A Systematic Review and Meta-analysis.

Importance: Observational studies have suggested that the use of radial artery grafts for coronary artery bypass grafting may improve clinical outcomes compared with the use of saphenous vein grafts, but this has not been confirmed in randomized trials. Objective: To compare clinical outcomes between patients receiving radial artery vs saphenous vein grafts for coronary artery bypass grafting after long-term follow-up. Design, Setting, and Participants: Patient-level pooled analysis comparing radial artery vs saphenous vein graft in adult patients undergoing isolated coronary artery bypass grafting from 5 countries (Australia, Italy, Serbia, South Korea, and the United Kingdom), with enrollment from 1997 to 2009 and follow-up completed in 2019. Interventions: Patients were randomized to undergo either radial artery (n = 534) or saphenous vein (n = 502) grafts for coronary artery bypass grafting. Main Outcomes and Measures: The primary outcome was a composite of death, myocardial infarction, or repeat revascularization and the secondary outcome was a composite of death or myocardial infarction. Results: A total of 1036 patients were randomized (mean age, 66.6 years in the radial artery group vs 67.1 years in the saphenous vein group; 376 [70.4%] men in the radial artery group vs 351 [69.9%] in the saphenous vein group); 942 (90.9%) of the originally randomized patients completed 10 years of follow-up (510 in the radial artery group). At a median (interquartile range) follow-up of 10 (10-11) years, the use of the radial artery, compared with the saphenous vein, in coronary artery bypass grafting was associated with a statistically significant reduction in the incidence of the composite outcome of death, myocardial infarction, or repeat revascularization (220 vs 237 total events; 41 vs 47 events per 1000 patient-years; hazard ratio, 0.73 [95% CI, 0.61-0.88]; P < .001) and of the composite of death or myocardial infarction (188 vs 193 total events; 35 vs 38 events per 1000 patient-years; hazard ratio, 0.77 [95% CI, 0.63-0.94]; P = .01). Conclusions and Relevance: In this individual participant data meta-analysis with a median follow-up of 10 years, among patients undergoing coronary artery bypass grafting, the use of the radial artery compared with the saphenous vein was associated with a lower risk of a composite of cardiovascular outcomes.

The Effect of Recombinant Undercarboxylated Osteocalcin on Endothelial Dysfunction.

Low circulating levels of undercarboxylated osteocalcin (ucOC) is associated with a higher risk of cardiovascular disease, yet whether ucOC has a direct effect on endothelium-dependent vasorelaxation, or in proximity to its postulated receptor, the class CG protein-coupled receptor (GPCR6A), in blood vessels remains unclear. Immunohistochemistry and proximity ligation assays were used to localize the presence of ucOC and GPRC6A and to determine the physical proximity (< 40 nm) in radial artery segments collected from patients undergoing coronary artery bypass surgery (n = 6) which exhibited calcification (determined by Von Kossa) and aorta from New Zealand white rabbits exhibiting atherosclerotic plaques. Endothelium-dependent vasorelaxation was assessed using cumulative doses of acetylcholine in vitro on abdominal aorta of rabbits fed a normal chow diet (n = 10) and a 4-week atherogenic diet (n = 9) pre-incubated with ucOC (10 ng/mL) or vehicle. Both ucOC and GPRC6A were localized in human and rabbit diseased-blood vessels. Proximity ligation assay staining demonstrated physical proximity of ucOC with GPRC6A only within plaques in rabbit arteries and the endothelium layer of rabbit arterioles. Endothelium-dependent vasorelaxation was impaired in atherogenic abdominal aorta compared to healthy aorta and ucOC attenuated this impairment. ucOC attenuated impaired endothelium-dependent vasorelaxation in rabbit abdominal aorta following an atherogenic diet, however, this effect may be independent of GPRC6A. It is important that future studies determine the underlying cellular mechanisms by which ucOC effects blood vessels as well as whether it can be used as a therapeutic agent against the progression of atherosclerosis.

Lipid management in high risk coronary patients: how effective are we at secondary intervention?

OBJECTIVE: To assess the proportion of patients who achieve and maintain target lipid levels during optimum long term follow up after coronary bypass surgery. METHODS: From a prospectively compiled database, we identified 440 patients followed for up to 13 years after CABG as part of a radial artery randomised controlled trial. All available lipid assays conducted during the follow-up period were collected from pathology databases. These were used to calculate the annualised mean lipid exposure for each patient. Based upon National Heart Foundation guidelines, we determined the proportion of patients whose mean lipid exposure attained target levels (total cholesterol <4.0 mmol/L, LDL-C <2.0 mmol/L, HDL-C >1.0 mmol/L and triglycerides <1.5 mmol/L). This was compared with the proportion who had achieved these targets pre-operatively and on their most recent cholesterol measurement. RESULTS: 6077 lipid studies (total cholesterol, LDL, HDL and triglycerides) in total were obtained. In those who had baseline data available, target levels for total cholesterol, HDL-C, LDL-C and triglycerides were attained pre-operatively by 16%, 64%, 14% and 39% of patients respectively. Annualised mean lipid exposures during up to 13 years of follow up for all patients revealed somewhat improved but still suboptimal target attainment figures of 24%, 83%, 20% and 53%. The most recent review shows the greatest improvement at 47%, 68%, 43% and 62% respectively. Of 141 diabetic patients, target attainment was significantly higher for total cholesterol (31%; p=0.038) and LDL-C (28%; p=0.006) but lower for HDL-C (75%; p=0.002) and triglycerides (40%; p<0.001). CONCLUSION: Despite some improvements seen over careful follow up, only HDL-C targets appear attainable for the majority of CABG patients. Over half still do not achieve non-HDL national lipid targets.

Coronary artery bypass surgery provides long-term results superior to percutaneous coronary intervention.

Traditionally, patients presenting with symptoms of coronary artery disease (CAD) were managed medically. If medical treatment proved unsuccessful, patients were referred for coronary artery bypass surgery (CABG). However, in recent years, increasing numbers of patients have received percutaneous coronary intervention (PCI), usually a coronary stent, for primary treatment. PCI is attractive because it is minimally invasive, has proven success in the immediate treatment of acute myocardial infarction and is well-accepted for poor surgical candidates in selected cases. However, evidence from emerging and ongoing clinical trials and registries suggests that compared to PCI, CABG offers superior long-term prognostic benefits in many, if not most, patients with significant CAD. We present an analysis of recent evidence showing that patients with complex atherosclerotic lesions, multivessel disease, left main stem disease, left ventricular dysfunction and diabetes mellitus derive more benefit from surgical revascularisation than from PCI. We conclude that PCI should be restricted to patient groups where superiority or equivalence to CABG has been demonstrated and that the decision-making process in allocating treatment should be made by a multidisciplinary team to ensure that every patient receives balanced advice and therapy that is most effective in the long term.

The right internal thoracic artery: is it underutilized?

PURPOSE OF REVIEW: The left internal thoracic artery is acknowledged as the best coronary conduit. The right internal thoracic artery (RITA) is identical to the left ITA (LITA), yet, despite excellent published results, the RITA [as part of bilateral ITA (BITA) grafting] is rarely used in coronary artery bypass graft surgery (CABG). With advances in CABG and drug-eluting stents (DESs) for coronary artery disease, it is timely to review the clinical and patency results when RITA is used in BITA, to define its role in the treatment of multivessel coronary artery disease. RECENT FINDINGS: RITA use is 4% in the USA, and 10% in the UK and Australia, although higher in some centres. Perioperative mortality of BITA is 1-3%. Morbidity is low, 1-2% for stroke and perioperative myocardial infarction, and 2-3% for postoperative bleeding. Deep sternal wound infection is also low, 1-3%. Excellent results are reported for RITA/BITA in off-pump coronary artery bypass, in patients with renal dysfunction and those with end-stage renal failure and on dialysis. BITA is well tolerated in routine diabetic patients with multivessel coronary disease and may enhance their long-term prognosis. Patencies for RITA are identical to LITA in comparable territories and superior to non-ITA grafts, resulting in enhanced long-term patient outcomes. SUMMARY: As evidence of excellent RITA results increases, strategies are required to encourage its use. Skeletonization, free, and composite grafts, associated with excellent clinical results and patencies, enhance RITA versatility and are important in improving long-term prognosis. The role of BITA/CABG versus DESs also needs further definition.

The Radial Artery Patency and Clinical Outcomes trial: design, intermediate term results and future direction.

The Radial Artery Patency and Clinical Outcomes Study (RAPCO) was devised and implemented in Melbourne in order to establish the appropriate place of the radial artery in the hierarchy of conduits available to the modern coronary bypass surgeon. Designed as a biological comparison with minimisation of other confounding variables, it compares this free arterial graft with the right internal thoracic artery and saphenous vein, with all conduits used in an identical fashion in two parallel cohorts of different age ranges. Enrolment was completed in 2004 and 10-year follow-up is in progress, with mean duration of about seven years at present. The midterm clinical and angiographic results to date are reviewed here, but definitive conclusions will not be possible until full completion angiographic data is available. The trial data provides a number of potential substudies of conduits, risk factors for failure and the natural history of treated coronary disease.

Quality control activities associated with registries in interventional cardiology and surgery.

OBJECTIVE: To describe and outline audit and quality control activities of the multicentre interventional and cardiac surgery registry in Victoria as a potential model for a national registry. DESIGN, SETTING, AND PATIENTS: The Melbourne Interventional Group (MIG) database is a prospective multicentre registry recording consecutive percutaneous coronary interventional (PCI) procedures across eight Victorian hospitals. Similarly, the Australasian Society of Cardiac and Thoracic Surgeons (ASCTS) database captures cardiac surgical activity across six Victorian hospitals. Auditing of each registry involved systematic selection of baseline, clinical and procedural variables from 5% of procedures to examine for data integrity and mismatches. MAIN OUTCOME MEASURES: Performance trend and data accuracy of each registry was assessed by the number of mismatches detected during the auditing process for different demographic, clinical and procedural variables and across different (de-identified) sites. RESULTS: Over two auditing phases from 2004-2006 and 2007, 10 (4.3%) of variables from 3% of all PCI procedures and 15 (6.4%) variables from 5% of PCI procedures were analysed. There was 96.5% agreement during the first auditing phase of the MIG registry with an average of 0.35 mismatches per audit (CI 0.28-0.42), whereas during the second audit phase, agreement was up to 97% with 0.32 mismatches per 10 fields per audit (CI 0.25-0.40). The ASCTS database audit selected 39 (14.8%) variables from 5% of annual surgical cases across six cardiac surgical centres with an overall 96.7% agreement. CONCLUSION: The current auditing process of these two databases is rigorous, robust and reflects a high degree of accuracy of data collected by participating hospitals.

Decreased catecholamine degradation associates with shock and kidney injury after cardiac surgery.

Enzymatic pathways involving catechol-O-methyltransferase (COMT) catabolize circulating catecholamines. A G-to-A polymorphism in the fourth exon of the COMT gene results in a valine-to-methionine amino acid substitution at codon 158, which leads to thermolability and low ("L"), as opposed to high ("H"), enzymatic activity. We enrolled 260 patients postbypass surgery to test the hypothesis that COMT gene variants impair circulating catecholamine metabolism, predisposing to shock and acute kidney injury (AKI) after cardiac surgery. In accordance with the Hardy-Weinberg equilibrium, we identified 64 (24.6%) homozygous (LL), 123 (47.3%) heterozygous (HL), and 73 (28.1%) homozygous (HH) patients. Postoperative catecholamines were higher in homozygous LL patients compared with heterozygous HL and homozygous HH patients (P < 0.01). During their intensive care stay, LL patients had both a significantly greater frequency of vasodilatory shock (LL: 69%, HL: 57%, HH: 47%; P = 0.033) and a significantly longer median duration of shock (LL: 18.5 h, HL: 14.0 h, HH: 11.0 h; P = 0.013). LL patients also had a greater frequency of AKI (LL: 31%, HL: 19.5%, HH: 13.7%; P = 0.038) and their AKI was more severe as defined by a need for renal replacement therapy (LL: 7.8%, HL: 2.4%, HH: 0%; P = 0.026). The LL genotype associated with intensive care and hospital length of stay (P < 0.001 and P = 0.002, respectively), and we observed a trend for higher mortality. Cross-validation analysis revealed a similar graded relationship of adverse outcomes by genotype. In summary, this study identifies COMT LL homozygosity as an independent risk factor for shock, AKI, and hospital stay after cardiac surgery. (ClinicalTrials.gov number, NCT00334009).

Impact of chronic kidney disease on patient outcome following cardiac surgery.

BACKGROUND: Renal impairment is a major risk factor for cardiovascular disease. This study addressed clinical predictors of outcome following cardiac surgery, focusing on pre-operative renal dysfunction. METHODS: All patients undergoing cardiac surgery at Austin Health from June 1, 2001 to June 30, 2006, were included in the analysis. Logistic regression models were used to evaluate clinical factors predicting "operative mortality" and common post-operative complications. RESULTS: The operative mortality was 1.36% for coronary artery bypass grafting (CABG) alone (n=1027), 5.07% for valve surgery alone (n=217), 4.43% for combined CABG and valve surgery (n=158) and 11.11% for other cardiac surgical procedures (n=270). Amongst CABG alone patients, pre-operative renal impairment was a strong predictor of operative mortality, with a 35-43% increased risk of death (p=0.005) for every 10 ml/min/1.73 m(2) that the glomerular filtration rate was lower. Peripheral vascular disease, recent myocardial infarction and congestive cardiac failure also predicted operative mortality. Pre-operative renal impairment also increased the rate of various post-operative complications, as well as duration of admission. CONCLUSION: Renal dysfunction is significantly associated with increased mortality and morbidity following cardiac surgery and necessitates careful consideration in risk benefit analysis when considering cardiac surgery.

Sodium bicarbonate to prevent increases in serum creatinine after cardiac surgery: a pilot double-blind, randomized controlled trial.

OBJECTIVE: To test whether perioperative sodium bicarbonate infusion can attenuate postoperative increases in serum creatinine in cardiac surgical patients. DESIGN: Double-blind, randomized controlled trial. SETTING: Operating rooms and intensive care unit at a tertiary hospital. PATIENTS: Cohort of 100 cardiac surgical patients at increased risk of postoperative acute renal dysfunction. INTERVENTION: Patients were randomized to either 24 hrs of intravenous infusion of sodium bicarbonate (4 mmol/kg) or sodium chloride (4 mmol/kg). MEASUREMENTS AND MAIN RESULTS: The primary outcome measure was the proportion of patients developing acute renal dysfunction defined as a postoperative increase in plasma creatinine concentration >25% of baseline within the first five postoperative days. Secondary outcomes included changes in plasma creatinine, plasma urea, urinary neutrophil gelatinase-associated lipocalin, and urinary neutrophil gelatinase-associated lipocalin/urinary creatinine ratio. Patients were well balanced for baseline characteristics. Sodium bicarbonate infusion increased plasma bicarbonate concentration (p < 0.001), base excess (p < 0.001), plasma pH (p < 0.001), and urine pH (p < 0.001). Fewer patients in the sodium bicarbonate group (16 of 50) developed a postoperative increase in serum creatinine compared with control (26 of 50) (odds ratio 0.43 [95% confidence interval 0.19-0.98]), (p = 0.043). The increase in plasma creatinine, plasma urea, urinary neutrophil gelatinase-associated lipocalin, and urinary neutrophil gelatinase-associated lipocalin/urinary creatinine ratio was less in patients receiving sodium bicarbonate, (p = 0.014; p = 0.047; p = 0.009; p = 0.004). There were no significant side effects. CONCLUSIONS: Sodium bicarbonate loading and continuous infusion was associated with a lower incidence of acute renal dysfunction in cardiac surgical patients undergoing cardiopulmonary bypass. The findings of this pilot study justify further investigation. (ClinicalTrials.gov, NCT00334191).

Clinical characteristics and early mortality of patients undergoing coronary artery bypass grafting compared to percutaneous coronary intervention: insights from the Australasian Society of Cardiac and Thoracic Surgeons (ASCTS) and the Melbourne Interventional Group (MIG) Registries.

OBJECTIVES: Controversy continues over the optimal revascularisation strategy for patients with multi-vessel coronary artery disease. Clinical characteristics, risk profile, and mortality of patients undergoing coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) are thought to differ but there are limited contemporary comparative data. METHODS: We compared clinical characteristics, in-hospital and 30-day mortality of 3841 consecutive patients undergoing isolated CABG and 4417 undergoing PCI. Independent predictors of 30-day mortality were determined by multiple logistic regression analysis. RESULTS: CABG patients were older (p<0.01). The CABG group had a higher incidence of diabetes, heart failure, left ventricular ejection fraction <45%, multi-vessel coronary artery, peripheral vascular and cerebro-vascular disease (all p<0.01). Patients undergoing PCI had a higher incidence of recent myocardial infarction (MI) as the indication for revascularisation (p<0.01). In-hospital and 30-day mortality was 1.8% and 1.7% in the CABG group, and 1.4% and 1.8% in the PCI group, respectively. Independent predictors of 30-day mortality after CABG were age (odds ratio 1.1 per year, 95% confidence interval 1.0-1.1), cardiogenic shock (4.10, 1.7-10.5) and previous CABG (6.6, 2.4-17.7). Predictors after PCI were diabetes (2.7, 1.4-5.1), female gender (3.0, 1.6-5.5), renal failure (3.2, 1.2-8.0), MI<24h (4.0, 2.2-7.6), left main intervention (5.4, 1.0-27.7), heart failure (6.0, 2.6-14.0) and cardiogenic shock (11.7, 5.4-25.2). CONCLUSIONS: In contemporary clinical practice, CABG is preferred in patients with multi-vessel coronary and associated non-coronary vascular disease, while PCI is the dominant strategy for acute MI. Despite this, in-hospital and 30-day mortality rates were similar. Predictors of early mortality after CABG differ to those of PCI.

The RADial artery International ALliance (RADIAL) extended follow-up study: rationale and study protocol.

It is generally accepted that radial artery (RA) grafts have better mid-term patency rate compared to saphenous vein grafts. However, the clinical correlates of the improved patency rate are still debated. Observational studies have suggested increased survival and event-free survival for patients who receive an RA rather than a saphenous vein, but they are open to bias and confounders. The only evidence based on randomized data is a pooled meta-analysis of 6 randomized controlled trial comparing the RA and the saphenous vein published by the RADial artery International Alliance (RADIAL). In the RADIAL database, improved freedom from follow-up cardiac events (death, myocardial infarction and repeat revascularization) was found at 5-year follow-up in the RA arm. The most important limitation of the RADIAL analysis is that most of the included trials had an angiographic follow-up in the first 5 years and it is unclear whether the rate of repeat revascularization (the main driver of the composite outcome) was clinically indicated due to per-protocol angiographies. Here, we present the protocol for the long-term analysis of the RADIAL database. By extending the follow-up beyond the 5th postoperative year (all trials except 1 did not have angiographic follow-up beyond 5 years), we aim to provide data on the role of RA in coronary artery bypass surgery with respect to long-term outcomes.

Aspirin and Tranexamic Acid for Coronary Artery Surgery (ATACAS) Trial: rationale and design.

BACKGROUND: Despite some concern that recent aspirin ingestion increases blood loss after coronary artery surgery, there is some evidence that this may reduce thrombotic complications. In contrast, antifibrinolytic drugs can reduce blood loss in this setting, but there is concern that they may increase thrombotic complications. Published guidelines are limited by a lack of large randomized trials addressing the risks and benefits of each of these commonly used therapies in cardiac surgery. The ATACAS Trial is a study comparing aspirin, tranexamic acid, or both, with placebo in patients undergoing on-pump or off-pump coronary artery surgery. METHODS: We discuss the rationale for conducting ATACAS, a 4600-patient, multicenter randomized trial in at-risk coronary artery surgery, and the features of the ATACAS study design (objectives, end points, target population, allocation, treatments, patient follow-up, and analysis). CONCLUSIONS: The ATACAS Trial will be the largest study yet conducted to ascertain the benefits and risks of aspirin and antifibrinolytic therapy in coronary artery surgery. Results of the trial will guide the routine clinical care of patients in this setting.

Human diseased arteries contain cells expressing leukocytic and embryonic stem cell markers.

Recent evidence suggests that smooth muscle cells within the intima of diseased human blood vessels of the elderly population contain the embryonic form of smooth muscle cells. We wanted to explore the idea that human diseased vessels may contain other primitive cell types, such as pluripotent embryonic stem cells and hematopoietic stem cells. Radial and internal mammary arteries were collected from patients undergoing coronary artery bypass surgery; and coronary arteries, from hearts at autopsy and transplant. Immunohistochemistry was used to identify the embryonic stem cell markers Octomer-4; stage-specific embryonic antigens 1, 3, and 4; TRA-1-60; and TRA-1-81, and the leukocytic markers CD34, CD14, CD133, and CD64 in all vessels. We found that diseased human radial arteries contained the highest numbers of cells in the media- and intima-expressing markers of embryonic and leukocytic origin compared with diseased human coronary arteries. In nondiseased human vessels (internal mammary arteries), such cells were rarely observed. Granulation tissue within the diseased human arteries contained similar cells, and the angiogenic vessel endothelial cell layer also expressed these markers. It is concluded that diseased human blood vessels contain cells that express markers from leukocytic and embryonic origin. These results suggest that cells within human arteries might be able to differentiate into various cell types and that blood vessels might be a reservoir for such cells.

Effect of radial artery or saphenous vein conduit for the second graft on 6-year clinical outcome after coronary artery bypass grafting. Results of a randomised trial.

OBJECTIVES: In order to determine the best conduit for coronary targets other than the left anterior descending (LAD) artery, long-term clinical outcomes following revascularisation with a radial artery or saphenous vein graft were evaluated as part of the radial artery patency and clinical outcomes (RAPCO) study. METHODS: As part of the RAPCO protocol for this prospective, randomised, single-centre trial, patients aged over 70 years undergoing primary CABG were randomly assigned to use of a radial artery (n=113) or saphenous vein (n=112) to revascularise the best non-LAD coronary vessel. Follow-up was annual. Primary clinical end-points were death, myocardial infarction or need for revascularisation. Data were analysed by intention to treat. RESULTS: The preoperative demographics (age, gender, presence of hypertension or diabetes mellitus) and urgency of surgery did not differ significantly between the two groups. The allocated arterial or venous conduit was utilised as intended in 104/113 and 110/112 patients, respectively. Mean number of grafts was 3.2+/-0.9 and 3.3+/-0.7 in the two groups. During follow-up of mean duration 6.2 years (maximum 10.8 years) there were 16 deaths in each group and 9 vs 13 other events in the radial artery and saphenous vein groups, respectively. These clinical outcomes did not differ significantly (log rank p=0.98 for survival and p=0.52 for event-free survival). CONCLUSIONS: Use of a radial artery or saphenous vein for the second graft during primary CABG does not significantly influence clinical outcome at 6 years. Mean 5-year angiographic patency data are awaited, but from the patient's perspective the likelihood of a satisfactory long-term result is equivalent, whichever conduit is used.

Epworth Hospital cardiac surgery audit--2007.

A total of 498 patients underwent open-heart surgery in 2007 with 5 deaths (1%).There was no mortality in 248 patients who had de novo isolated coronary bypass surgery. Major mortality and morbidities were almost exclusively confined to patients over the age of 80 years. The development of new catheter based procedures such as aortic valve replacement is likely to decrease the complication rate and length of hospital stay in this high risk group of patients.

The combination of high dietary methionine plus cholesterol induces myocardial fibrosis in rabbits.

UNLABELLED: Limited evidence suggests that myocardial fibrosis might be associated with dietary cardiovascular risk factors. OBJECTIVE: To investigate the effects of high dietary cholesterol, methionine (the precursor to homocysteine), and the combination of the two diets on myocardial fibrosis. METHODS: Rabbits were randomly allocated into four dietary groups for 12 weeks: control (Con), 1% methionine (Meth), 0.5% cholesterol (Chol) or 1% methionine plus 0.5% cholesterol (MethChol). RESULTS: Myocardial fibrosis was not significantly increased in Chol or Meth. However, interstitial fibrosis increased by 85% (p = 0.03) and perivascular fibrosis 28-fold (p < 0.01) in the MethChol group compared to Con. CONCLUSIONS: These results suggest that high levels of dietary cholesterol or methionine alone do not significantly increase myocardial collagen content. However, the combination of the two diets does cause myocardial fibrosis. Therefore, excessive cholesterol and methionine intake may be an important pathogenic factor in the development of myocardial fibrosis.