Coronary Artery Bypass Patients Research Articles

Maximal blood flow acceleration analysis in the early diastolic phase for in situ internal thoracic artery bypass grafts: a new transit-time flow measurement predictor of graft failure following coronary artery bypass grafting.

Maximal graft flow acceleration (max df/dt) determined by transit-time flowmetry (TTFM) in the diastolic phase was assessed as a possible predictor of graft failure in coronary artery bypass patients. Max df/dt was retrospectively measured in 57 in situ left internal thoracic artery grafts. TTFM data were fitted to a 5-polynomial curve, which was derived from the first-derivative curve to measure max df/dt (5-polymial max df/dt). Abnormal TTFM was defined as a mean flow of <15 ml/min, pulsatility index of >5 or diastolic filling ratio of <50%. Postoperative coronary angiography (CAG) or multidetector computed tomography (MDCT) was performed within 1 year after surgery. The grafts were classified into four groups: Normal TTFM/Patent MDCT/CAG (N/P), Normal TTFM/Failing MDCT/CAG (N/F), Abnormal TTFM/Patent MDCT/CAG (Ab-N/P) and Abnormal TTFM/Failing MDCT/CAG graft (Ab-N/F). By TTFM, 34 grafts were normal, 5 of which were occluded on CAG, and 23 grafts were abnormal, six of which were occluded on CAG. There were significant differences in 5-polynomial max df/dt between each group pair (P < 0.05, Mann-Whitney U-test) except for the N/F:Ab-N/P group pair; especially, 5-polynomial max df/dt was significantly lower in the Ab-N/F group compared with the other groups (Ab-N/F: 0.89 ± 0.41 vs N/P: 4.74 ± 3.18, N/F: 2.23 ± 0.65, Ab-N/P: 2.70 ± 1.31 ml/s(2), P < 0.01, Mann-Whitney U-test). The sensitivity and specificity of 5-polynomial max df/dt were, respectively, 72.7 and 80.4% (cut-off value, 1.918 ml/s(2)) for all grafts and 100 and 88.2% (cut-off value, 1.273 ml/s(2)) for abnormal TTFM grafts. The TTFM 5-polymial max df/dt value in the early diastolic phase may be a promising predictor of future graft failure.

Elimination of routine chest radiographs following off-pump coronary artery bypass surgery: A randomized controlled trial study.

Background:Post cardiac surgery routine chest radiographs (CXRs), ordered without any clinical and laboratory indications, is a standard obligatory practice in many cardiothoracic centers. Routine CXRs incur cost, manpower, and radiation. The objective of this study is to assess early outcome in off-pump coronary artery bypass (OPCAB) patients with postoperative routine versus clinically indicated CXR protocols.Materials and Methods:This study is a randomized clinical trial conducted on 231 OPCAB candidates in Afshar Cardiac Center, Yazd, Iran. Patients were categorized into two groups. All 118 patients in group A had routine postoperative CXRs. The 113 patients in group B were selectively exposed to CXR only on clinical indications. All patients were postoperatively followed up for 30 days. Data gathered from both groups were statistically analyzed.Results:Routine postoperative CXRs obtained in 118 OPCAB group A candidates showed abnormal findings in 20 patients that did not require new intervention. One month follow-up of these patients showed no complications. In 113 OPCAB candidates of group B, 7 on-demand CXRs were obtained on clinical evaluation that required added intervention. In a 1-month follow-up of this group, five patients presented with symptomatic complaints. On re-examination, none needed readmission, intervention, or paraclinical evaluation. No complications were observed due to CXR elimination.Conclusion:The study suggests that postoperative CXR selected on clinical grounds in place of routine CXR does not change early postoperative outcome of OPCAB procedure.

Nonanalgesic benefits of combined thoracic epidural analgesia with general anesthesia in high risk elderly off pump coronary artery bypass patients

Objective:Epidural anesthesia is a central neuraxial block technique with many applications. It is a versatile anesthetic technique, with applications in surgery, obstetrics and pain control. Its versatility means it can be used as an anesthetic, as an analgesic adjuvant to general anesthesia, and for postoperative analgesia. Off pump coronary artery bypass (OPCAB) surgery triggers a systemic stress response as seen in coronary artery bypass grafting (CABG). Thoracic epidural anesthesia (TEA), combined with general anesthesia (GA) attenuates the stress response to CABG. There is Reduction in levels of Plasma epinephrine, Cortisol and catecholamine surge, tumor necrosis factor-Alpha(TNF ά), interleukin-6 and leucocyte count.Design:A prospective randomised non blind study.Setting:A clinical study in a multi specialty hospital.Participants:Eighty six patients.Material and Methods/intervention:The study was approved by hospital research ethics committee and written informed consent was obtained from all patients. Patients were randomised to receive either GA plus epidural (study group) or GA only (control group). Inclusion Criteria (for participants) were -Age ≥ 70 years, Patient posted for OPCAB surgery, and patient with comorbidities (diabetes mellitus, chronic obstructive pulmonary disease, cerebrovascular disease, peripheral vascular disease, renal dysfunction). Serum concentration of Interlukin: – 6, TNF ά, cortisol, Troponin – I, CK-MB, and HsCRP (highly sensitive C reactive protein), was compared for both the group and venous blood samples were collected and compared just after induction, at day 2, and day 5 postoperatively. Time to mobilization, extubation, total intensive care unit stay and hospital stay were noted and compared. Independent t test was used for statistical analysis.Primary Outcomes:Postoperative complications, total intensive care unit stay and hospital stay.Secondary Outcome:Stress response.Result:Study group showed decreased Interlukin – 6 at day 2, TNF ά at day 2 and 5, troponin I at day 5, and decreased total hospital stay (p < 0.05).Conclusion:Thoracic epidural anesthesia decreases stress and inflammatory response to surgery and decreases hospital stay. However a large multicentre study may be needed to confirm it.

Experience of percutaneous transluminal coronary angioplasty (PTCA) in post coronary artery bypass (CABG) patients at JJ Hospital

Experience of percutaneous transluminal coronary angioplasty (PTCA) in post coronary artery bypass (CABG) patients at JJ Hospital

Reducing cardiovascular risk in spouses of cardiac patients: a randomized controlled trial.

Few studies have examined risk-reducing interventions in spouses of coronary artery bypass patients. This study examined the effects of the Partners Together in Health (PaTH) intervention versus usual care on cardiovascular risk factors. Spouses in the experimental group (n = 17/group) attended cardiac rehabilitation with patients and made the same physical activity and healthy eating changes as patients. Spouses in the usual care group attended educational classes with patients. Spouses' 30-year cardiovascular risk was calculated using the Lifetime Risk Scale before and after cardiac rehabilitation (3 months), and at 6 months. Spouses in both groups significantly reduced 30-year risk scores at 3 and 6 months. Exercise was the key ingredient in lowering risk. There was a trend toward reduction in systolic blood pressure and an increase in high-density lipoprotein cholesterol in both groups. Although there were no group differences, having spouses participate in cardiac rehabilitation with the patient was effective for reducing spouses' cardiovascular risk.

Invited Commentary

Invited Commentary

Abstract 302: Generation of Patient-Specific Tissue-Engineered Blood Vessels From Nonintegrated Induced Pluripotent Stem Cells

Cell resourcing remains one of the major problems in the development of patient-specific TEBVs. The iPSC derived cardiovascular cells provide a promising source for TEBVs and cell therapy. The goal of this study is to construct TEBVs using patient-specific iPSCs. Using a non-integrated episomal vector based reprogramming system, we generated human iPSCs from peripheral blood mononuclear cells (PBMCs) isolated from the blood harvested from aneurysm patients with bicuspid aortic valves and coronary artery bypass patients with normal aortas and aortic valves. These iPSCs showed the expression of pluripotent markers and could differentiate into 3 layers of cells in vitro. We directed the iPSCs differentiation into vascular smooth muscle cells (VSMCs) in vitro. We documented the expression of VSMC markers, including smooth muscle α-actin (α-SMA), calponin and SM22α by quantitative real-time-PCR, immunocytochemistry, as well as Western-blotting. Furthermore, we confirmed that the iPSC-derived VSMCs could contract in response to carbachol, a muscarinic agonist. The treatment of iPSC-derived VSMCs with IL-1β, an atherogenic cytokine, changed MMPs (matrix metallopeptidases) activity. Finally, we found that iPSC-derived VSMCs could survive well and secrete collagen when transferred and cultured on PLLA scaffolds in vitro, suggesting a great cell sourcing for tissue-engineered blood vessels. Our data suggests that by using non-integrated iPSCs, we could efficiently differentiate patient-specific iPSCs into functional VSMCs, which may provide great cell sourcing for patient-specific TEBVs.

Prognostic value of Rb-82 positron emission tomography myocardial perfusion imaging in coronary artery bypass patients

We sought to determine the prognostic value of positron emission tomography (PET) myocardial perfusion imaging (MPI) in patients with prior coronary artery bypass graft (CABG) surgery. PET MPI has recently been shown to provide incremental risk stratification for patients with suspected coronary artery disease (CAD), but the prognostic utility of PET MPI in CABG patients has not been well studied. A multi-centre PET registry of 7061 patients who underwent Rb-82 PET MPI from four participating centres was screened. Nine hundred and fifty-three CABG patients were identified and their images were analysed. Outcomes of all-cause mortality and cardiac death were collected. With a mean follow-up of 2.4 ± 1.4 years, 128 (13.4%) all-cause deaths and 44 (4.6%) cardiac deaths were observed. Multivariable analyses, adjusted for clinical variables, demonstrated that the summed stress score (SSS) was a significant independent predictor of both all-cause mortality [HR: 1.60 (per 1 category increase in SSS); 95% CI: 1.34-1.92; P < 0.001] and cardiac death (HR: 1.80; 95% CI: 1.33, 2.44; P < 0.001). The receiver-operator characteristic (ROC) curves showed that the addition of SSS increased the area under the curve (AUC) from 0.645 to 0.693 (P = 0.014) for all-cause mortality, and from 0.612 to 0.704 (P = 0.027) for cardiac death. SSS also improved the net reclassification improvement (NRI) for all-cause mortality (category-free NRI = 0.422; 95% CI: 0.240-0.603; P < 0.001) and cardiac death (category-free NRI = 0.552; 95% CI: 0.268-0.836; P < 0.001). PET MPI provides independent and incremental prognostic value to clinical variables in predicting all-cause mortality and cardiac death in CABG patients.

Coronary Artery Bypass Grafting Versus Drug-Eluting Stents in Patients with End-Stage Renal Disease

The optimal treatment for multivessel coronary artery disease in patients with end-stage renal disease (ESRD) is unresolved. Compare clinical adverse events after percutaneous intervention with drug-eluting stents (DESs) and coronary artery bypass grafting (CABG) in patients with ESRD. MEDLINE, Web of Science, and Scopus were searched for appropriate studies published in the English language (between January 2000 and August 2013). The pooled odds ratio (OR) was estimated by the Peto method with a random effect model. Data are presented with 95% confidence interval; p<0.05 is significant. Five observational studies (12,035 DES patients; 6317 CABG) with a follow-up period of 27.4 ± 6.3 months were included. Early mortality (CABG 8% and DES 2.6%) was less in the DES cohort (OR 0.29 [0.14-0.59]; p=0.0006; I(2)=18%). Repeat intervention (DES 29% and CABG 12%) was more likely in the DES cohort (OR 3.72 [2.24-6.18]: p<0.0001). Late mortality (27.4 ± 7.3 months) was comparable in both cohorts (OR 0.72 [0.40-1.29]; p=0.27). While DES cohort (32%) patients suffered a slightly higher incidence of major adverse cardiac and cerebrovascular events (MACCE) as compared to CABG (25%), this was not significant (1.35 [0.72-2.53]; p=0.35; I(2)=30%). Data regarding this topic are limited to small retrospective studies. Early mortality is lower with DESs compared with coronary artery bypass in patients with ESRD. Rate of reintervention is significantly higher in the DES cohort. At a mean pooled follow-up of two years, both mortality and MACCE are comparable in both cohorts.

Coronary artery bypass in patients with type 2 diabetes: Experience from the Bypass Angioplasty Revascularization Investigation 2 Diabetes trial

Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) was a study of management strategies for diabetic patients with myocardial ischemia and coronary artery disease. In a 2×2 design, early revascularization versus medical management with or without late revascularization and insulin sensitization versus insulin provision were examined. No advantage for either strategy was seen, except in the group undergoing early coronary artery bypass grafting (CABG). In that group, a reduction in subsequent myocardial infarction was noted. The purpose of our report was to characterize the conduct and short-term outcomes for CABG that led to this result. Data from the BARI 2D CABG stratum were collected, including the baseline demographic and cardiovascular characteristics, technical details of the operation, and perioperative morbidity and mortality, and analyzed. A total of 347 patients were studied. The average cardiac function was normal, and most had multivessel disease. Almost all had undergone CABG by way of a median sternotomy using an internal mammary artery, and one third were off pump. The perioperative morbidity and mortality were low and compared well with larger outcomes databases. BARI 2D showed that early CABG in patients with type 2 diabetes and myocardial ischemia and multivessel disease reduced the subsequent myocardial infarction rates. The present results have demonstrated that this was achieved using off-pump surgery in certain cases, standard myocardial protection, and routine use of the internal mammary artery or other arterial grafts.

Is There a Role for Robotic Totally Endoscopic Coronary Artery Bypass in Patients With a Colostomy?

Preoperative colostomy presents a significant risk of sternal wound complications, mediastinitis, and ostomy injury in patients requiring coronary artery bypass grafting. Less invasive procedures in coronary surgery have a potential to reduce the risk of sternal wound healing problems. Robotic totally endoscopic coronary artery bypass grafting in patients with a colostomy has not been reported. We describe a case of completely endoscopic coronary surgery using the da Vinci Si system in a patient with a transverse colostomy. Single left internal mammary artery grafting to the left anterior coronary artery was performed successfully on the beating heart. We regard this technique as the least invasive method of surgical coronary revascularization with a potential to reduce the risk of surgical site infection and mediastinitis in patients with a colostomy.

Comparing the effectiveness of neutrophil-lymphocyte ratio as a mortality predictor on middle and advanced age coronary artery bypass graft patients.

OBJECTIVE:In this study, the effect of neutrophil-lymphocyte ratio (NLR), which is a recently developed inflammatory parameter, as an early stage mortality predictive marker on coronary artery bypass (CABG) patients of various age groups was examined.METHODS:Seventy eight patients under the age of 45 (Group 1) and 80 patients who were older than 45 (Group 2) randomly chosen from the patients who underwent isolated CABG surgery, were examined. The preoperative characteristics and NLRs were noted. The primary end point of the study was determined as all-cause in- hospital mortality.RESULTS:Mortality was observed in 2 patients in Group 1 and 11 patients in Group 2. The threshold value of NLR was 2,47 in the Receiver Operating Characteristic (ROC) curve in Group 1 and there wasn’t any significant correlation between preoperative NLR and mortality rates in the patients whose NLRs were above this curve. The threshold value was determined as 4.07 in Group 2 and there was a significant relation between preoperative NLR and mortality (p<0,01). No relation was found between NLR and mortality when all the examined patients were considered (p>0.05).CONCLUSION:NLR that can be easily calculated, can be used as a mortality predictor in the patients of advanced age who will undergo isolated CABG procedure.

S100 and S100β: biomarkers of cerebral damage in cardiac surgery with or without the use of cardiopulmonary bypass.

ObjectiveThe present study is to describe the clinical impact of S100 and S100β for the evaluation of cerebral damage in cardiac surgery with or without the use of cardiopulmonary bypass (CPB).MethodsQuantitative results of S100 and S100β reported in the literature of the year range 1990-2014 were collected, screened and analyzed.ResultsCerebrospinal fluid and serum S100 levels showed a same trend reaching a peak at the end of CPB. The cerebrospinal fluid/serum S100 ratio decreased during CPB, reached a nadir at 6 h after CPB and then increased and kept high untill 24 h after CPB. Serum S100 at the end of CPB was much higher in infant than in adults, and in on-pump than in off-pump coronary artery bypass patients. ∆S100 increased with age and CPB time but lack of statistical significances. Patients receiving an aorta replacement had a much higher ∆S100 than those receiving a congenital heart defect repair. Serum S100β reached a peak at the end of CPB, whereas cerebrospinal fluid S100 continued to increase and reached a peak at 6 h after CPB. The cerebrospinal fluid/serum S100β ratio decreased during CPB, increased at the end of CPB, peaked 1 h after CPB, and then decreased abruptly. The increase of serum S100β at the end of CPB was associated with type of operation, younger age, lower core temperature and cerebral damages. ∆S100β displayed a decreasing trend with age, type of operation, shortening of CPB duration, increasing core temperature, lessening severity of cerebral damage and the application of intervenes. Linear correlation analysis revealed that serum S100β concentration at the end of CPB correlated closely with CPB duration.ConclusionS100 and S100β in cerebrospinal fluid can be more accurate than in the serum for the evaluations of cerebral damage in cardiac surgery. However, cerebrospinal fluid biopsies are limited. But serum S100β and ∆S100β seem to be more sensitive than serum S100 and ∆S100. The cerebral damage in cardiac surgery might be associated with younger age, lower core temperature and longer CPB duration during the operation. Effective intervenes with modified CPB circuit filters or oxygenators and supplemented anesthetic agents or priming components may alleviate the cerebral damage.

Factors influencing the participation of post coronary artery bypass patients in cardiac rehabilitation exercise

Studies have shown that cardiovascular rehabilitation exercise improves quality of life in post-coronary-bypass-surgery patients. However, the rate of participation in this exercise by this patient group in Taiwan has increased only 8.2% during the past 13 years (from 61.9% in 1996 to 70.1% in 2009). Little is known about the factors that influence patient motivation to participate in cardiovascular rehabilitation exercise. This study explores the factors that influence patient participation in rehabilitation exercise following coronary bypass surgery. This cross-sectional, correlational study recruited a convenience sample of 253 patients who had undergone coronary bypass surgery at a medical center in southern Taiwan. Structured questionnaires, including a patient rehabilitation exercise experience questionnaire, Short Form-36 Health Survey-Taiwan Form, and cardiac rehabilitation exercise design factors questionnaire were used for data collection. SPSS19.0 was used to analyze data. The variables "healthcare provider recommendation of rehabilitation exercise", "exercise program accessibility", "physical health status", and "patient post-surgical exercise patterns" each had a significant influence on participant participation in post-surgical rehabilitation exercise. Binary logistic regression analyses identified "receiving information on rehabilitation exercise", "level of patient-perceived importance of rehabilitation exercise", and "having post-surgical exercise patterns" as important predictors of participation in a rehabilitation exercise program, with OR ratios of 112, 7.86, and 3.23 times respectively. These 3 factors accounted for 90.1% of the total variance. Patient education on coronary bypass post-surgical rehabilitation exercise programs should be emphasized during pre-surgical consultation and care in order to facilitate the recovery of normal life functions following coronary bypass surgery.

Changes of cardiac troponin I and operative mortality of coronary artery bypass

Recently, cardiac troponin I has been used to detect myocardial injury because of its superior cardiac specificity. However, there has been debate about the appropriate timing and cutoff level of cardiac troponin I to detect perioperative myocardial injury after coronary artery bypass grafting. The objective of this study was to define the relationship between operative mortality and changes in cardiac troponin I after isolated coronary artery bypass. A retrospective analysis was carried out on data of 218 isolated coronary artery bypass patients who were operated on between June 2009 and February 2012. All patients followed an institutional perioperative management protocol that included 6 cardiac troponin I measurements (preoperatively and 0, 12, 24, 36, and 48 h after coronary artery bypass). According to the patterns of cardiac troponin I, the patient cohort was divided into 2 groups. Group 1 was patients in whom cardiac troponin I levels decreased 24 h after the operation, and group 2 comprised the patients with cardiac troponin I levels that did not decrease or even increased after 24 h. The operative mortality was 4.1% (9/218). Group 2 showed significantly higher mortality (5/25, 20%) than group 1 (4/193, 2.1%). An elevated cardiac troponin I level is common after coronary artery bypass. A persistently high level of cardiac troponin I after 24 h is an important predictor of operative mortality after coronary artery bypass surgery.

Clinical and echocardiographic predicators of postoperative atrial fibrillation.

Postoperative atrial fibrillation is the most common arrhythmiaafter coronary artery bypass grafting,with a reported incidence of 10% to 60%. Preoperative clinical and echocardiographic data, especially the atrial electromechanical interval, predict postoperative atrial fibrillation in elective coronary artery bypass patients. A prospective study evaluated preoperative clinical and echocardiographic data in 192 patients who underwent elective coronary artery bypass from 2010 to 2012. 18 (9.37%) patients developed postoperative atrial fibrillation. Compared to patients without postoperative atrial fibrillation, these 18 had significantly longer intensive care unit and hospital stays, they were significantly older (58.62 ± 10.02 vs. 53.22 ± 8.23 years; p = 0.02), with a larger left atrial volume (83.39 ± 8.31 vs. 55.47 ± 8.37 cm(3), p = 0.001), longer atrial electromechanical interval (133.67 ± 8.15 vs. 98.05 ± 6.71 ms p < 0.0001), and lower tissue Doppler imaging systolic velocity wave amplitude (6.6 ± 1 vs. 9.4 ± 2.2 cm·s(-1); p = 0.001); they also had a higher prevalence of hypertension (61.11% vs. 38.5%; p = 0.04). Using 115 ms as the cutoff value of atrial electromechanical interval enabled us to detect patients who developed postoperative atrial fibrillation with 100% sensitivity, 77% specificity, 78% positive predictive value, and 100% negative predictive value. Older hypertensive patients are at higher risk of developing postoperative atrial fibrillation. Preoperative measurement of atrial electromechanical interval by tissue Doppler echocardiography is a useful predictor of postoperative atrial fibrillation in coronary artery bypass patients.

Doxycycline Reduces Cardiac Matrix Metalloproteinase-2 Activity but Does not Ameliorate Myocardial Dysfunction During Reperfusion in Coronary Artery Bypass Patients Undergoing Cardiopulmonary Bypass

Matrix metalloproteinase-2 proteolyzes intracellular proteins in the heart and induces acute myocardial contractile dysfunction in ischemia-reperfusion injury. Doxycycline, a matrix metalloproteinase inhibitor, prevented matrix metalloproteinase-2-induced troponin I cleavage in rat hearts and improved contractile function following ischemia-reperfusion. In patients undergoing coronary artery bypass graft surgery with cardiopulmonary bypass, increased atrial matrix metalloproteinase-2 activity was inversely correlated with cardiac mechanical function at 3 hours reperfusion. We performed a study in patients with coronary artery disease undergoing primary elective coronary artery bypass graft surgery with cardiopulmonary bypass to determine whether doxycycline reduces cardiac mechanical dysfunction, matrix metalloproteinase activity, and troponin I degradation after reperfusion. Randomized, double-blinded, placebo-controlled study. University of Alberta Hospital. Forty-two patients with coronary artery disease undergoing coronary artery bypass graft surgery with cardiopulmonary bypass. Patients were randomized to receive either oral administration of 20 mg of doxycycline or matching placebo pill twice a day at least 2 days prior to surgery, on the day of surgery, and for the first 3 postoperative days. Left ventricular stroke work index was examined prior to cardiopulmonary bypass and at 24 hours reperfusion. Right atrial biopsies were collected before cardiopulmonary bypass and 10 minutes after aortic cross-clamp release to determine matrix metalloproteinase-2 activity and troponin I level. Blood was collected to determine matrix metalloproteinase activity and interleukin-6, C-reactive protein, and troponin I levels. Cardiac 72-kDa matrix metalloproteinase-2 activity was lower upon reperfusion in biopsies from the doxycycline group (p = 0.01), and the increase of matrix metalloproteinase-2 activity in the placebo group due to reperfusion did not appear in the doxycycline group (p = 0.05). Doxycycline, however, did not ameliorate cardiac mechanical dysfunction following reperfusion or the cardiopulmonary bypass-coronary artery bypass graft-induced increased plasma matrix metalloproteinase-9, interleukin-6, and C-reactive protein levels. Cardiopulmonary bypass-coronary artery bypass graft or doxycycline did not change tissue or plasma troponin I levels at 10 minutes reperfusion. Although doxycycline did not improve myocardial stunning following coronary artery bypass graft surgery with cardiopulmonary bypass, it reduced cardiac matrix metalloproteinase-2 activity in these patients. A larger trial and/or higher dose of doxycycline may yet be warranted.

Regression of coronary disease after bypass surgery: Urban myth or common finding?

Coronary artery disease has been viewed as a relentless, progressive disease. We sought to describe the prevalence and distribution of regression of native vessel disease in coronary artery bypass patients and characterize its relationship with bypass grafting. Among 619 patients who underwent bypass surgery in a radial artery trial, 405 had follow-up angiography available a mean of 6.2 ± 3.1 years (range, 0-14) after surgery. The percentage of diameter stenosis of each major native coronary vessel was reported by 3 cardiac specialists and classified into grades of nonflow limiting (0%-39%), moderate (40%-69%), flow limiting (70%-80%), severely stenosed (81%-99%), and occluded (100%). Native vessel disease regression was defined as decrease in 1 or more grades of stenosis between the pre- and postoperative angiograms. A total of 1742 native coronary arteries had preoperative stenosis of at least 40% and were included in the present analysis, receiving 753 arterial grafts and 391 saphenous vein grafts. Overall, the prevalence of disease regression was 19.7%, and 45% of patients demonstrated regression in 1 or more vessels. The presence of an arterial graft increased the likelihood of disease regression (21.3% compared with 16% for venous bypassed vessels, P=.012) as did the location in the left circulation (22.6% compared with 13.9% for the right circulation, P<.001) and having a flow-limiting (≥70%) lesion (21.9% compared with 9.8% for moderate lesions, P<.001). Native coronary artery disease regression after coronary artery bypass grafting is common and affected by conduit type, vessel location, and lesion severity. Surgeons must consider these factors when assessing the requirement for bypass grafts in a borderline lesion.

Sternal wrapping: developments and results

Postoperative sternal wound complications are infrequent events that negatively affect recovery and may have serious consequences. Sternal wrapping, a technique of sternal care, has hemostatic properties without bone wax, and offers mechanical and microbiologic protection. From February 1998 to December 2011, 258 patients in 2 Italian institutions underwent various cardiac surgery procedures with sternal wrapping in place, and were followed up for no less then 6 months. Two (0.8%) extremely compromised patients with ischemic sternal osteonecrosis and deep sternal wound infection required a sternal stabilizing procedure. Four (2%) other patients developed sternal wound complications that were treated entirely medically; 3 of them were very trivial, and 1 was an atypical mediastinitis without sternal involvement. Overall, 46.1% of patients (45.3% of isolated coronary artery bypass, 49.3% of isolated on-pump coronary artery bypass, and 18.2% of off-pump coronary artery bypass patients) were transfused. None of the complications was related to sternal wrapping, bleeding from the sternal edge, or sternal wound problems. Sternal wrapping showed a very low incidence and severity of sternal wound complications, with good prevention of sternal osteomyelitis. Hemostatic properties were satisfactory, with transfusion rates within an acceptable range.

Modern antiplatelet management of coronary artery bypass patients: a role of platelet function testing in decision making

We read with great interest the recently published study by Williams et al. [1]. The authors sought to determine the relationship between postoperative clopidogrel and clinical and angiographic outcomes following coronary artery bypass grafting (CABG) [1]. Although clopidogrel is now recommended as postoperative antiplatelet therapy in patients with recent acute coronary syndromes, some other circumstances such as off-pump CABG, performed endarterectomy, and extensive severe coronary artery disease with small target vessels, warrant the use of both clopidogrel and aspirin following surgical revascularization [2]. In present study by Williams et al. [1], postoperative antiplatelet therapy was left to physician discretion, thus creating patient selection bias since above mentioned circumstances requiring dual antiplatelet therapy (dAPT) could influence angiographic as well as clinical outcomes. Aortocoronary vein graft disease is composed of three distinct but interrelated pathological processes: thrombosis, intimal hyperplasia, and atherosclerosis [3]. Early thrombosis is a major cause of vein graft attrition during the first month after CABG [3]. Since the present study assessed clinical outcome [1] it would be interesting if authors included in analysis patients who died prior to 30 days postoperatively. It would be interesting to elucidate how many patients of those who died prior to 30 days postoperatively were on dAPT versus mono antiplatelet therapy early after CABG? In our opinion, the lack of data concerning objective quantification of the antiplatelet effect of aspirin and clopidogrel constitutes a major drawback of the study. Expected inhibition of platelet function is not always achieved after aspirin and/or clopidogrel administration. The frequency of low responsiveness for the 2 drugs has been reported to range from 1 to 45 % [4, 5] and such a phenomenon could certainly explain in some degree ischemic events after CABG. When assessing relationship between postoperative dAPT and both clinical and angiographic outcomes following CABG, the role of aspirin should inextricably be included into considerations. Within dAPT the possible impact of each antiplatelet agent (aspirin and clopidogrel) on clinical and angiographic outcomes should separately be assessed by drug specific platelet function tests, facilitating individual therapeutic approach for each antiplatelet agent postoperatively. Such an approach could distinguish patients with high residual platelet activity, thus proclivity to ischemic events, from those with enhanced platelet inhibition, thus proclivity to bleeding events (notably, not captured in present trial). In our recent study [5], we analyzed the proportion of patients with aspirin resistance, both preand postoperatively. Considering all CABG patients, we observed 31/99 (31.3 %) patients with aspirin resistance preoperatively [5]. Postoperatively, we registered 46/99 (46.5 %) CABG patients with aspirin resistance, suggesting platelet hyperactivity [5]. A postoperatively registered increase of 15.2 % in the proportion of patients with aspirin resistance was found to be significant (p = 0.04) as well as higher prevalence of aspirin resistance within diabetic subpopulation (58.5 vs 38 %, p = 0.04). Postoperatively, we observed significant increase in values of platelet function M. Petricevic (&) B. Biocina I. Safradin Department of Cardiac Surgery, University Hospital Center Zagreb, University of Zagreb School of Medicine, Kispaticeva 12, 10000 Zagreb, Croatia e-mail: petricevic.mate@gmail.com