Ahmet Ruchan Akar

Off-Pump or On-Pump Coronary-Artery Bypass Grafting at 30 Days

BACKGROUND The relative benefits and risks of performing coronary-artery bypass grafting (CABG) with a beating-heart technique (off-pump CABG), as compared with cardiopulmonary bypass (on-pump CABG), are not clearly established. METHODS At 79 centers in 19 countries, we randomly assigned 4752 patients in whom CABG was planned to undergo the procedure off-pump or on-pump. The first coprimary outcome was a composite of death, nonfatal stroke, nonfatal myocardial infarction, or new renal failure requiring dialysis at 30 days after randomization. RESULTS There was no significant difference in the rate of the primary composite outcome between off-pump and on-pump CABG (9.8% vs. 10.3%; hazard ratio for the off-pump group, 0.95; 95% confidence interval [CI], 0.79 to 1.14; P=0.59) or in any of its individual components. The use of off-pump CABG, as compared with on-pump CABG, significantly reduced the rates of blood-product transfusion (50.7% vs. 63.3%; relative risk, 0.80; 95% CI, 0.75 to 0.85; P<0.001), reoperation for perioperative bleeding (1.4% vs. 2.4%; relative risk, 0.61; 95% CI, 0.40 to 0.93; P=0.02), acute kidney injury (28.0% vs. 32.1%; relative risk, 0.87; 95% CI, 0.80 to 0.96; P=0.01), and respiratory complications (5.9% vs. 7.5%; relative risk, 0.79; 95% CI, 0.63 to 0.98; P=0.03) but increased the rate of early repeat revascularizations (0.7% vs. 0.2%; hazard ratio, 4.01; 95% CI, 1.34 to 12.0; P=0.01). CONCLUSIONS There was no significant difference between off-pump and on-pump CABG with respect to the 30-day rate of death, myocardial infarction, stroke, or renal failure requiring dialysis. The use of off-pump CABG resulted in reduced rates of transfusion, reoperation for perioperative bleeding, respiratory complications, and acute kidney injury but also resulted in an increased risk of early revascularization. (Funded by the Canadian Institutes of Health Research; CORONARY ClinicalTrials.gov number, NCT00463294.).

Effects of Off-Pump and On-Pump Coronary-Artery Bypass Grafting at 1 Year

BACKGROUND Previously, we reported that there was no significant difference at 30 days in the rate of a primary composite outcome of death, myocardial infarction, stroke, or new renal failure requiring dialysis between patients who underwent coronary-artery bypass grafting (CABG) performed with a beating-heart technique (off-pump) and those who underwent CABG performed with cardiopulmonary bypass (on-pump). We now report results on quality of life and cognitive function and on clinical outcomes at 1 year. METHODS We enrolled 4752 patients with coronary artery disease who were scheduled to undergo CABG and randomly assigned them to undergo the procedure off-pump or on-pump. Patients were enrolled at 79 centers in 19 countries. We assessed quality of life and cognitive function at discharge, at 30 days, and at 1 year and clinical outcomes at 1 year. RESULTS At 1 year, there was no significant difference in the rate of the primary composite outcome between off-pump and on-pump CABG (12.1% and 13.3%, respectively; hazard ratio with off-pump CABG, 0.91; 95% confidence interval [CI], 0.77 to 1.07; P=0.24). The rate of the primary outcome was also similar in the two groups in the period between 31 days and 1 year (hazard ratio, 0.79; 95% CI, 0.55 to 1.13; P=0.19). The rate of repeat coronary revascularization at 1 year was 1.4% in the off-pump group and 0.8% in the on-pump group (hazard ratio, 1.66; 95% CI, 0.95 to 2.89; P=0.07). There were no significant differences between the two groups at 1 year in measures of quality of life or neurocognitive function. CONCLUSIONS At 1 year after CABG, there was no significant difference between off-pump and on-pump CABG with respect to the primary composite outcome, the rate of repeat coronary revascularization, quality of life, or neurocognitive function. (Funded by the Canadian Institutes of Health Research; CORONARY ClinicalTrials.gov number, NCT00463294.).

Comparison of original EuroSCORE, EuroSCORE II and STS risk models in a Turkish cardiac surgical cohort

OBJECTIVES The aim of this study was to compare additive and logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE), EuroSCORE II and the Society of Thoracic Surgeons (STS) models in calculating mortality risk in a Turkish cardiac surgical population. METHODS The current patient population consisted of 428 patients who underwent isolated coronary artery bypass grafting (CABG) between 2004 and 2012, extracted from the TurkoSCORE database. Observed and predicted mortalities were compared for the additive/logistic EuroSCORE, EuroSCORE II and STS risk calculator. The area under the receiver operating characteristics curve (AUC) values were calculated for these models to compare predictive power. RESULTS The mean patient age was 74.5 ± 3.9 years at the time of surgery, and 35.0% were female. For the entire cohort, actual hospital mortality was 7.9% (n = 34; 95% confidence interval [CI] 5.4-10.5). However, the additive EuroSCORE-predicted mortality was 6.4% (P = 0.23 vs observed; 95% CI 6.2-6.6), logistic EuroSCORE-predicted mortality was 7.9% (P = 0.98 vs observed; 95% CI 7.3-8.6), EuroSCORE II- predicted mortality was 1.7% (P = 0.00 vs observed; 95% CI 1.6-1.8) and STS predicted mortality was 5.8% (P = 0.10 vs observed; 95% CI 5.4-6.2). The mean predictive performance of the analysed models for the entire cohort was fair, with 0.7 (95% CI 0.60-0.79). AUC values for additive EuroSCORE, logistic EuroSCORE, EuroSCORE II and STS risk calculator were 0.70 (95% CI 0.60-0.79), 0.70 (95% CI 0.59-0.80), 0.72 (95% CI 0.62-0.81) and 0.62 (95% CI 0.51-0.73), respectively. CONCLUSIONS EuroSCORE II significantly underestimated mortality risk for Turkish cardiac patients, whereas additive and logistic EuroSCORE and STS risk calculators were well calibrated.

A prescription fraud detection model

Prescription fraud is a main problem that causes substantial monetary loss in health care systems. We aimed to develop a model for detecting cases of prescription fraud and test it on real world data from a large multi-center medical prescription database. Conventionally, prescription fraud detection is conducted on random samples by human experts. However, the samples might be misleading and manual detection is costly. We propose a novel distance based on data-mining approach for assessing the fraudulent risk of prescriptions regarding cross-features. Final tests have been conducted on adult cardiac surgery database. The results obtained from experiments reveal that the proposed model works considerably well with a true positive rate of 77.4% and a false positive rate of 6% for the fraudulent medical prescriptions. The proposed model has the potential advantages including on-line risk prediction for prescription fraud, off-line analysis of high-risk prescriptions by human experts, and self-learning ability by regular updates of the integrative data sets. We conclude that incorporating such a system in health authorities, social security agencies and insurance companies would improve efficiency of internal review to ensure compliance with the law, and radically decrease human-expert auditing costs.

Five-year follow-up after transepicardial implantation of autologous bone marrow mononuclear cells to ungraftable coronary territories for patients with ischaemic cardiomyopathy

OBJECTIVE Cell therapy for patients with ischaemic cardiomyopathy (IC) is still an open issue. We aimed to assess the long-term safety and therapeutic potency of autologous bone marrow mononuclear cell (ABMMNC) implantation into ungraftable coronary artery (UCA) territories in patients with IC. METHODS Bone marrow was aspirated from the iliac crest, and transepicardial ABMMNC implantation (n=25, 24 men, aged 57+/-7 years) as an adjunct to coronary artery bypass grafting (CABG) was performed into an area of reversible ischaemia within the territory of UCA (1.29+/-0.09 x 10(9) ABMMNCs). Control group (n=25, 23 men, aged 59+/-7 years) underwent incomplete CABG due to poor target vessel graftability. The study protocol consisted of coronary angiography, stress echocardiography, nuclear imaging and Holter monitoring at baseline and follow-up. The mean follow-up time was 988+/-423 days. RESULTS There was no difference between the groups regarding postoperative complications and outcome. Overall 5-year survival for the ABMMNC group was 79+/-10%, and 71+/-12% for the controls (p=0.48). Left ventricular ejection fraction (LVEF) at baseline was 24.8+/-3.7 versus 25.9+/-3.1 in the ABMMNC group and the controls, respectively. After 6 months, mean global LVEF increased to 36.3+/-7.4 (p<0.001) versus 31.4+/-4.1 (p=0.001), respectively. A significant difference was noted in delta LVEF between the groups (p<0.001, 95% confidence interval (CI): 3.4-8.9) at 6 months, and (p=0.001, 95% CI: 2.0-7.4) at 1 year. Accordingly, perfusion scores in UCA segments detected by single-photon emission computed tomography (SPECT) improved with ABMMNC therapy to 18.0+/-24.4 from 7.1+/-25.7 (p=0.001 vs control UCA segments). CONCLUSION Cellular therapy for IC within UCA could augment myocardial perfusion and contractility but does not improve overall survival. No adverse events were detected after cell therapy at mid-term follow-up.

Vacuum-assisted closure and bilateral pectoralis muscle flaps for different stages of mediastinitis after cardiac surgery

PurposeTo assess the results of bilateral pectoralis major muscle flaps (BPMMF) and vacuum-assisted closure (VAC) at different stages of postcardiac surgery mediastinitis.MethodsOf 65 patients with a deep sternal wound infection (DSWI) after cardiac surgery, 33 with a stable sternum were treated with VAC (59.3 ± 11.7 years of age) and 32 with an unstable sternum or osteomyelitis (63.3 ± 9.8 years of age) were treated with early BPMMF and continuous irrigation. Delayed BPMMF reconstruction was necessary in six VAC patients.ResultsThe overall incidence of DSWI was 1.04% within the study period. Deep sternal wound infection was diagnosed 15.9 ± 10.8 days (range 5–62 days) after surgery. Diabetes was more common in the BPMMF group than in the VAC group (P = 0.046). Hospital mortality after treatment was 4.6% (n = 3) overall. Causes of death were septic multiorgan failure and respiratory failure. The infective pathogens were methicillin-resistant Staphylococcus aureus (MRSA; n = 2) and Acinetobacter species (n = 1). The median hospital stay was 29 days (range 15–110 days). After 6 months, only one recurrent sternal infection had occurred in the VAC group.ConclusionsEarly BPMMF is an effective surgical treatment for DSWI in patients with an unstable sternum and osteomyelitis. VAC may be considered for patients without osteomyelitis but a stable sternum, or as adjuvant therapy in patients with comorbidity.

Apoptotic Vascular Smooth Muscle Cell Depletion via BCL2 Family of Proteins in Human Ascending Aortic Aneurysm and Dissection

AIMS This study investigates the expression patterns of BCL2 (B-cell CLL/lymphoma2) family of proteins and the extent of vascular smooth muscle cell (VSMC) apoptosis in thoracic aortic aneurysms (TAA), type-A aortic dissections (TAD), and nondilated ascending aortic samples. METHODS Aortic wall specimens were obtained from patients undergoing surgical repair for TAA (n = 24), TAD (n = 20), and normal aortic tissues from organ donors (n = 6). The expression pattern of BCL2, BCL2L1 (BCL2-like1), BAK1 (BCL2-antagonist/killer1), and BAX (BCL2-associated X protein) proteins was investigated by immunohistochemistry. Furthermore, colocalization of alpha smooth muscle actin (ACTA2) and caspase3 (CASP3) in aortic VSMCs was analyzed by double-immunofluorescence staining. Onset of DNA fragmentation was measured by TUNEL assay. RESULTS Apoptotic index was significantly increased in both TAD group (31.3 ± 17.2, P < 0.001) and TAA group (21.1 ± 12.7, P = 0.001) relative to control aortas (2.0 ± 1.2). Anti-CASP3 and ACTA2 double-immunostaining confirmed apoptosis in VSMCs in TAA and TAD groups but not in controls. Proapoptotic BAX expression was significantly elevated in VSMCs of TAA patients, compared with that of controls (OR = 20; P = 0.02; 95% CI, 16-250). In contrast, antiapoptotic BCL2L1 expression was higher in controls compared with that of TAA group (OR = 11.2; P = 0.049; 95% CI, 1.0-123.9). Furthermore, BAX/BCL2 ratio was significantly increased in both TAA (1.2 ± 0.7, P < 0.001) and TAD (0.6 ± 0.4, P = 0.05) groups relative to controls (0.2 ± 0.1, P < 0.001). CONCLUSIONS Apoptotic VSMC depletion in human TAA/TAD is associated with disturbance of the balance between proapoptotic and antiapoptotic members of the BCL2 family proteins, which may have a role in the pathogenesis of vascular remodelling in aortic disease. In light of the future studies, targeting apoptotic pathways in TAA and TAD pathogenesis may provide therapeutic benefits to patients by slowing down the progression and even possibly preventing the TAD.

Validation of the EuroSCORE risk models in Turkish adult cardiac surgical population

OBJECTIVE The aim of this study was to validate additive and logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) models on Turkish adult cardiac surgical population. METHODS TurkoSCORE project involves a reliable web-based database to build up Turkish risk stratification models. Current patient population consisted of 9443 adult patients who underwent cardiac surgery between 2005 and 2010. However, the additive and logistic EuroSCORE models were applied to only 8018 patients whose EuroSCORE determinants were complete. Observed and predicted mortalities were compared for low-, medium-, and high-risk groups. RESULTS The mean patient age was 59.5 years (± 12.1 years) at the time of surgery, and 28.6% were female. There were significant differences (all p<0.001) in the prevalence of recent myocardial infarction (23.5% vs 9.7%), moderate left ventricular function (29.9% vs 25.6%), unstable angina (9.8% vs 8.0%), chronic pulmonary disease (13.4% vs 3.9%), active endocarditis (3.2% vs 1.1%), critical preoperative state (9.0% vs 4.1%), surgery on thoracic aorta (3.7% vs 2.4%), extracardiac arteriopathy (8.6% vs 11.3%), previous cardiac surgery (4.1% vs 7.3%), and other than isolated coronary artery bypass graft (CABG; 23.0% vs 36.4%) between Turkish and European cardiac surgical populations, respectively. For the entire cohort, actual hospital mortality was 1.96% (n=157; 95% confidence interval (CI), 1.70-2.32). However, additive predicted mortality was 2.98% (p<0.001 vs observed; 95%CI, 2.90-3.00), and logistic predicted mortality was 3.17% (p<0.001 vs observed; 95%CI, 3.03-3.21). The predictive performance of EuroSCORE models for the entire cohort was fair with 0.757 (95%CI, 0.717-0.797) AUC value (area under the receiver operating characteristic, AUC) for additive EuroSCORE, and 0.760 (95%CI, 0.721-0.800) AUC value for logistic EuroSCORE. Observed hospital mortality for isolated CABG was 1.23% (n=75; 95%CI, 0.95-1.51) while additive and logistic predicted mortalities were 2.87% (95%CI, 2.82-2.93) and 2.89% (95%CI, 2.80-2.98), respectively. AUC values for the isolated CABG subset were 0.768 (95%CI, 0.707-0.830) and 0.766 (95%CI, 0.705-0.828) for additive and logistic EuroSCORE models. CONCLUSION The original EuroSCORE risk models overestimated mortality at all risk subgroups in Turkish population. Remodeling strategies for EuroSCORE or creation of a new model is warranted for future studies in Turkey.

The efficacies of modified mechanical post conditioning on myocardial protection for patients undergoing coronary artery bypass grafting

BackgroundCoronary artery bypass grafting (CABG) with cardioplegic cardiac arrest and cardiopulmonary bypass (CPB) is associated with myocardial injury. The aim of this study was to investigate whether a modified mechanical post-conditioning (MMPOC) technique has a myocardial protective effect by enhancing early metabolic recovery of the heart following revascularization.MethodsA prospective, randomized trial was conducted at a single-center university hospital performing adult cardiac surgery. Seventy-nine adult patients undergoing first-time elective isolated multivessel coronary artery bypass grafting were prospectively randomized to MMPOC or control group. Anesthetic, cardiopulmonary bypass, myocardial protection, and surgical techniques were standardized. The post reperfusion cardiac indices, inotrope use and biochemical-electrocardiographic evidence of myocardial injury were recorded. The incidence of postoperative complications was recorded prospectively.ResultsOperative characteristics, including CPB and aortic cross-clamp time, were similar between the two groups (p>0.05). The MMPOC group had lower troponin I and other cardiac biomarkers level post CPB and postoperatively, with greater improvement in cardiac indices (p<0.001). MMPOC shortened post surgery hospitalization from 9.1 ± 2.1 to 7.5 ± 1.6 days (p<0.001).ConclusionsMMPOC technique promotes early metabolic recovery of the heart during elective CABG, leading to better myocardial protection and functional recovery.

Statin pretreatment and risk of in-hospital atrial fibrillation among patients undergoing cardiac surgery: a collaborative meta-analysis of 11 randomized controlled trials

AIMS Statin pretreatment in patients undergoing cardiac surgery is understood to prevent postoperative atrial fibrillation (AF). However, this is based on observational and limited randomized trial evidence, resulting in uncertainty about any genuine anti-arrhythmic benefits of these agents in this setting. We therefore aimed to quantify precisely the association between statin pretreatment and postoperative AF among patients undergoing cardiac surgery. METHODS AND RESULTS A detailed search of MEDLINE and PubMed databases (1st January 1996 to 31st July 2012) was conducted, followed by a review of the reference lists of published studies and correspondence with trial investigators to obtain individual-participant data for meta-analysis. Evidence was combined across prospective, randomized clinical trials that compared the risk of postoperative AF among individuals randomized to statin pretreatment or placebo/control medication before elective cardiac surgery. Postoperative AF was defined as episodes of AF lasting ≥5 min. Overall, 1105 participants from 11 trials were included; of them, 552 received statin therapy preoperatively. Postoperative AF occurred in 19% of these participants when compared with 36% of those not treated with statins (odds ratio 0.41, 95% confidence interval 0.31-0.54, P < 0.00001, using a random-effects model). Atrial fibrillation prevention by statin pretreatment was consistent across different subgroups. CONCLUSION Short-term statin pretreatment may reduce the risk of postoperative AF among patients undergoing cardiac surgery.