Randomized trial of aspirin and clopidogrel versus aspirin alone for the prevention of coronary artery bypass graft occlusion: the Preoperative Aspirin and Postoperative Antiplatelets in Coronary Artery Bypass Grafting study

Preventive medication efficacy after 1-year follow-up for graft failure in coronary artery bypass surgery patients: Bayesian network meta-analysis

To compare preventive medications against graft failures in coronary artery bypass graft surgery (CABG) patients after a 1-year follow-up. Systematic review with Bayesian network meta-analysis and meta-regression analysis. We searched PubMed, Scopus, and Web of Science databases in February 2023 for randomized controlled trials, comparing preventive medications against graft failure in CABG patients. We included studies that reported outcomes at 1 year after surgery. Our primary outcome was graft failure After screening 11,898 studies, a total of 18 randomized trials were included. Acetylsalicylic acid (ASA) [odds ratios (OR) 0.51, 95% credibility interval (CrI) 0.28-0.95, meta-regression OR 0.54, 95% CrI 0.26-1.00], Clopidogrel + ASA (OR 0.27, 95% CrI 0.09-0.76, meta-regression OR 0.28, 95% CrI 0.09-0.85), dipyridamole + ASA (OR 0.50, 95% CrI 0.30-0.83, meta-regression OR 0.49, 95% CrI 0.26-0.90), ticagrelor (OR 0.40, 95% CrI 0.16-1.00, meta-regression OR 0.43, 95% CrI 0.15-1.2), and ticagrelor + ASA (OR 0.26, 95% CrI 0.10-0.62, meta-regression OR 0.28, 95% CrI 0.10-0.68) were superior to placebo in preventing graft failure. Rank probabilities suggested the highest likelihood to be the most efficacious for ticagrelor + ASA [surface under the cumulative ranking (SUCRA) 0.859] and clopidogrel + ASA (SUCRA 0.819). The 95% CrIs of ORs for mortality, bleeding, and major adverse cardio- and cerebrovascular events (MACE) were wide. A trend towards increased bleeding risk and decreased MACE risk was observed when any of the medication regimens were used when compared to placebo. Sensitivity analysis excluding studies with a high risk of bias yielded equivalent results. Of the reviewed medication regimens, dual antiplatelet therapy combining ASA with ticagrelor or clopidogrel was found to result in the lowest rate of graft failures.

Safety outcomes of anti-platelet therapy post coronary artery bypass graft surgery: A systematic review and network meta-analysis of randomized control trials

BACKGROUND

Antiplatelet therapy is used to decrease the risk of graft failure post coronary artery bypass graft surgery. We aimed to compare dual antiplatelet therapy (DAPT) with monotherapy along with a comparison of Aspirin, Ticagrelor, Aspirin+Ticagrelor (A+T) and Aspirin+Clopidogrel (A+C) to determine the major and minor bleeding risk, risk of postoperative myocardial infarction (MI), stroke, and all-cause mortality (ACM).

METHODS

Randomized Controlled Trials comparing the four groups were included. Odds ratio (OR) and Absolute Risk (AR) were employed to assess the mean and standard deviation (SD) with 95% confidence intervals (CI). The Bayesian random-effects model was used for statistical analysis. Risk difference and Cochran Q tests were used to calculate rank probability (RP) and heterogeneity, respectively.

RESULTS

We included 10 trials, consisting of 21 arms and 3926 patients. For the risk of major and minor bleed, A + T and Ticagrelor showed the lowest mean value of 0.040 (0.043) and 0.067 (0.073), respectively, and the highest RP of being the safest group. While a direct comparison between DAPT and monotherapy resulted in an OR of 0.57 [0.34, 0.95] for the risk of minor bleed. A + T was found to have the highest RP and the lowest mean value in terms of ACM, MI, and stroke.

CONCLUSION

No significant difference was found between monotherapy or dual-antiplatelet therapy for the major bleeding risk safety outcome, however DAPT was found to have a significantly higher rate of minor bleeding complications post-CABG. DAPT should be considered as the antiplatelet modality of choice post-CABG.

Antithrombotic strategies for preventing graft failure in coronary artery bypass graft

Coronary artery bypass graft (CABG) procedures face challenges related to graft failure, driven by factors such as acute thrombosis, neointimal hyperplasia, and atherosclerotic plaque formation. Despite extensive efforts over four decades, the optimal antithrombotic strategy to prevent graft occlusion while minimizing bleeding risks remains uncertain, relying heavily on expert opinions rather than definitive guidelines. To address this uncertainty, we conducted a review of randomized clinical trials and meta-analyses of antithrombotic therapy for patients with CABG. These studies examined various antithrombotic regimens in CABG such as single antiplatelet therapy (aspirin or P2Y12 inhibitors), dual antiplatelet therapy, and anticoagulation therapy. We evaluated outcomes including the patency of grafts, major adverse cardiovascular events, and bleeding complications and also explored future perspectives to enhance long-term outcomes for CABG patients. Early studies established aspirin as a key component of antithrombotic pharmacotherapy after CABG. Subsequent randomized controlled trials focused on adding a P2Y12 inhibitor (such as clopidogrel, ticagrelor, or prasugrel) to aspirin, yielding mixed results. This article aims to inform clinical decision-making and guide the selection of antithrombotic strategies after CABG.

Stroke prevention strategies for cardiac surgery: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Stroke is a much-feared complication of cardiac surgery, but existing literature on preventive strategies is fragmented. Hence, a systematic review and meta-analysis of stroke prevention strategies for cardiac surgery was conducted.

METHODS

An electronic literature search was conducted to retrieve randomized controlled trials (RCTs) investigating perioperative interventions for cardiac surgery, with stroke as an outcome. Random-effects meta-analyses were conducted to generate risk ratios (RRs), 95% confidence intervals (95% CI), and forest plots. Descriptive analysis and synthesis of literature was conducted for interventions not amenable to meta-analysis, focusing on risks of stroke, myocardial infarction and study-defined major adverse cardiovascular events (MACE).

RESULTS

Fifty-six RCTs (61 894 patients) were retrieved. Many included trials were underpowered to detect differences in stroke risk. Among pharmacological therapies, only preoperative amiodarone was shown to reduce stroke risk in one trial. Concomitant left atrial appendage closure (LAAC) significantly reduced stroke risk (RR = 0.55, 95% CI = 0.36-0.84, P = 0.006) in patients with preoperative atrial fibrillation, and there was no difference in on-pump versus off-pump coronary artery bypass grafting (CABG) (RR = 0.94, 95% CI = 0.64-1.37, P = 0.735). Much controversy exists in literature on the timing of carotid endarterectomy relative to CABG in patients with severe carotid stenosis. The use of preoperative remote ischemic preconditioning was not found to reduce rates of stroke or MACE.

CONCLUSION

This review presents a comprehensive synthesis of existing interventions for stroke prevention in cardiac surgery, and identifies gaps in research which may benefit from future, large-scale RCTs. LAAC should be considered to reduce stroke incidence in patients with preoperative atrial fibrillation.

Dual-Antiplatelet Therapy After Coronary Artery Bypass Grafting: A Survey of UK Cardiac Surgeons

OBJECTIVE

Antiplatelet therapy after coronary artery bypass grafting (CABG) is important in postoperative medical management. Although cardiac surgeons are well-versed in the guidelines regarding discontinuation of dual-antiplatelet therapy (DAPT; aspirin and a P2Y12 antagonist) before CABG to minimize bleeding risk, there is considerable variability in DAPT dosing after CABG. The objective of this study was to explore the current trends in DAPT after CABG in the UK to improve understanding of the existing practice.

DESIGN

This study used an online survey with 9 questions about the use of DAPT after CABG. An invitation to participate was sent to all adult cardiac surgeons currently in practice in the UK and the Republic of Ireland.

SETTING

The study was conducted in the UK and the Republic of Ireland.

PARTICIPANTS

Participants in this study were adult cardiac surgeons currently in practice in the UK and the Republic of Ireland.

INTERVENTIONS

There were no interventions in this study.

MEASUREMENTS AND MAIN RESULTS

Responses were received from across the UK (85.4% UK; 4% each from Scotland and Northern Ireland, 1.3% from Wales) and 5.3% from the Republic of Ireland. Fifty-seven percent of the respondents performed between 50 and 100 CABGs per year. Ninety-one percent of the respondents prescribe DAPT postoperatively, but the choice of which patients receive it varied. Most responding surgeons used DAPT for selective patient cohorts, such as those with acute coronary syndrome (51%), diffuse coronary artery disease (42%), perioperative myocardial infarction (36%), coronary endarterectomy (31%), or when bypassing a stented coronary artery (23%). Thirty-eight percent of the respondents began all their patients with CABGs on DAPT. The most preferred P2Y12 antagonist was clopidogrel, used by 75% of respondents and introduced on day 1 after surgical revascularization (71%). The routine duration for DAPT is 12 months, which 78% of the respondents preferred. The main reason for not starting DAPT in those surveyed was the bleeding risk associated with DAPT (72%).

CONCLUSIONS

The survey uncovered variation in the use of DAPT after CABG. However, DAPT remains the preferred strategy after CABG in the UK. The study highlighted the need to develop standardized protocols for DAPT after CABG.

Mechanobiology of the endothelium in vascular health and disease: in vitro shear stress models

In recent years, there has been growing evidence that vascular pathologies arise in sites experiencing an altered haemodynamic environment. Fluid shear stress (FSS) is an important contributor to vascular homeostasis and regulates endothelial cell (EC) gene expression, morphology, and behaviour through specialised mechanosensitive signalling pathways. The presence of an altered FSS profile is a pathological characteristic of many vascular diseases, with the most established example being the preferential localisation of atherosclerotic plaque development. However, the precise haemodynamic contributions to other vascular pathologies including coronary artery vein graft failure remains poorly defined. To evaluate potential novel therapeutics for the treatment of vascular diseases via targeting EC behaviour, it is important to undertake in vitro experiments using appropriate culture conditions, particularly FSS. There are a wide range of in vitro models used to study the effect of FSS on the cultured endothelium, each with the ability to generate FSS flow profiles through which the investigator can control haemodynamic parameters including flow magnitude and directionality. An important consideration for selection of an appropriate model of FSS exposure is the FSS profile that the model can generate, in comparison to the physiological and pathophysiological haemodynamic environment of the vessel of interest. A resource bringing together the haemodynamic environment characteristic of atherosclerosis pathology and the flow profiles generated by in vitro methods of applying FSS would be beneficial to researchers when selecting the appropriate model for their research. Consequently, here we summarise the widely used methods of exposing cultured endothelium to FSS, the flow profile they generate and their advantages and limitations in investigating the pathological contribution of altered FSS to vascular disease and evaluating novel therapeutic targets for the treatment and prevention of vascular disease.

CYP2C19 genotype and platelet aggregation test-guided dual antiplatelet therapy after off-pump coronary artery bypass grafting: A retrospective cohort study

Background

Dual antiplatelet therapy (DAPT) is recommended in patients undergoing off-pump coronary artery bypass graft surgery (OPCAB). Clopidogrel is less effective among patients with loss-of-function (LoF) of CYP2C19 alleles, while ticagrelor has direct effects on P2Y₁₂ receptor. Whether a CYP2C19 genotype plus platelet aggregation test (PAgT)-guided DAPT after CABG could improve clinical outcomes remain uncertain.

Materials and methods

From August 2019 to December 2020, 1,134 consecutive patients who underwent OPCAB received DAPT for 1 year after surgery in Ruijin Hospital, Shanghai Jiao Tong University School of Medicine. According to the actual treatment they received in real-world, 382 (33.7%) of them received a traditional DAPT: aspirin 100 mg qd + clopidogrel 75 mg qd, no matter the CYP2C19 genotype and response in platelet aggregation test (PAgT). The other 752 (66.3%) patients received an individual DAPT based on CYP2C19 genotype and PAgT: aspirin 100 mg qd + clopidogrel 75 mg qd if CYP2C19 was extensive metabolizer, or moderate metabolizer but normal response in PAgT; aspirin 100 mg qd + ticagrelor 90 mg bid if CYP2C19 was poor metabolizer, or moderate metabolizer but no or low response in PAgT. One-year follow-up was achieved for all patients. The primary outcome was major adverse cardiovascular events (MACE), a composite of cardiovascular death, myocardial infarction, and stroke. The safety outcome was thrombolysis in myocardial infarction (TIMI) criteria major bleeding.

Results

Compared with the traditional DAPT group, the risk of MACE in the individual DAPT group was significantly lower (5.5 vs. 9.2%, HR 0.583; 95% CI, 0.371-0.915; P = 0.019), mainly due to the decreased risk of MI (1.7 vs. 4.2%, HR 0.407; 95% CI, 0.196-0.846; P = 0.016). The risk of TIMI major bleeding events was similar between the two groups (5.3 vs. 6.0%, RR 0.883; 95% CI, 0.537-1.453; P = 0.626).

Conclusion

For patients who underwent OPCAB, individual DAPT (CYP2C19 genotype plus PAgT-guided strategy) was associated with a lower risk of MACE and a similar risk of major bleeding.

Safety Comparison of Monotherapy Aspirin to Dual Antiplatelet Therapy Following Coronary Artery Bypass Surgery

BACKGROUND

Dual antiplatelet therapy (DAPT) is recommended over single antiplatelet therapy (SAPT) in patients following coronary artery bypass grafting (CABG). The compilation of evidence has focused on the efficacy of DAPT to limit risk of graft occlusion, however the safety, especially in the on-pump CABG population, is less well described. The aim of this study was to assess the safety of DAPT versus SAPT after on-pump CABG.

METHODS

This was a single-center, retrospective cohort analysis of adult patients following isolated on-pump CABG between January 2012 and December 2019 not on oral anticoagulation at discharge. The primary endpoint was occurrence of a composite bleeding event identified by pre-specified ICD codes. Secondary endpoints consisted of 30-day and 1-year mortalities along with individual bleeding components.

RESULTS

Of the 2341 patients included 1250 patients were in the SAPT arm and 1091 patients in the DAPT arm. The study populations differed by age, prior MI, PAD, and CHF status/stage. Bleeding events occurred in a total of 70 patients (3.0%), with 36 patients (2.9%) in the SAPT arm and 34 patients (3.1%) in the DAPT arm (P = .74). 30-day (SAPT 0.7% vs DAPT 0.4%) and 1-year (SAPT 3.3% vs DAPT 2.3%) mortality were not significantly different between groups. The most frequent bleed event was in the gastrointestinal tract.

CONCLUSION

In this study, DAPT was not associated with an increase in composite bleeding compared to SAPT. This study could reduce the barrier to prescribing of DAPT given previous efficacy data.

The relationship between dual antiplatelet treatment (DAPT) score and saphenous venous grafts patency after coronary artery bypass grafting surgery

BACKGROUND

Coronary artery bypass grafting (CABG) remains the gold standard treatment for mutivessel and left main coronary artery disease (CAD). Saphenous vein graft (SVG) patency is still a problem in CAD patients after CABG surgery. The Dual Antiplatelet Treatment (DAPT) score is a clinical prediction tool that predicts ischaemic and bleeding risk in CAD patients. The aim of this study is to investigate the relationship between DAPT score and SVG patency in CABG patients.

METHOD

This retrospective study enrolled a total of 398 patients (68 female; mean age 65.8 ± 9.1 years) with a history of CABG surgery. The study population was divided into two subgroups according to SVG patency. The DAPT score was calculated for each patients and compared between the two groups.

RESULTS

Coronary angiography revealed SVG disease in 212 patients and SVG patency in 186 patients. The rates of diabetes mellitus and hypertension, red cell distribution width values, DAPT Score, time interval after CABG and number of SVGs were significantly higher while LVEF was significantly lower in patients with SVG disease. The presence of diabetes mellitus, high DAPT score, long time interval after CABG and high number of SVGs were found to be independent predictors of SVG patency. DAPT score above 2.5 predicted SVG disease with a sensitivity of 77.1% and a specificity of 87.1% (AUC: 0.873; 95%CI: 0.823-0.924; p < 0.001).

CONCLUSION

The DAPT score may provide useful information for SVG patency in CABG patients. Patients with high DAPT score should be followed up closely for SGV occlusion. DAPT score may be useful prior to CABG in determining the duration of dual anti-platelet therapy and in encouraging the use of arterial grafts with better patency.

Saphenous Vein Graft Failure: From Pathophysiology to Prevention and Treatment Strategies

Saphenous vein grafts (SVGs) remain the most frequently used conduits in coronary artery bypass graft surgery (CABG). Despite advances in surgical techniques and pharmacotherapy, SVG failure rates remain high, often leading to repeat coronary revascularization. The no-touch SVG harvesting technique (minimal graft manipulation with preservation of vasa vasorum and nerves) reduces the risk of SVG failure, whereas the effect of the off-pump technique on SVG patency remains unclear. Use of buffered storage solutions, intraoperative graft flow measurement, careful selection of the target vessels, and physiological assessment of the native coronary circulation before CABG may also reduce the incidence of SVG failure. Perioperative aspirin and high-intensity statin administration are the cornerstones of secondary prevention after CABG. Dual antiplatelet therapy is recommended for off-pump CABG and in patients with a recent acute coronary syndrome. Intermediate (30%-60%) SVG stenoses often progress rapidly. Stenting of intermediate SVG stenoses failed to improve outcomes; hence, treatment focuses on strict control of coronary artery disease risk factors. Redo CABG is associated with higher perioperative mortality compared with percutaneous coronary intervention (PCI); hence, the latter is preferred for most patients requiring repeat revascularization after CABG. SVG PCI is limited by high rates of no-reflow and a high incidence of restenosis during follow-up. Drug-eluting and bare metal stents provide similar long-term outcomes in SVG PCI. Embolic protection devices reduce no-reflow and should be used when feasible. PCI of the corresponding native coronary artery is associated with better short- and long-term outcomes and is preferred over SVG PCI, if technically feasible.

Dual Antiplatelet Therapy with Clopidogrel and Aspirin Versus Aspirin Monotherapy in Patients Undergoing Coronary Artery Bypass Graft Surgery

Background The optimal antiplatelet therapy after coronary artery bypass grafting remains unclear. We evaluated the association of dual antiplatelet therapy (DAPT) with clopidogrel plus aspirin and clinical outcomes among patients undergoing coronary artery bypass grafting. Methods and Results A total of 18 069 consecutive patients who underwent primary isolated coronary artery bypass grafting between 2013 and 2017 were identified from a contemporary registry, and 10 854 (60.1%) received DAPT with clopidogrel plus aspirin as determined by claimed prescriptions after surgery. Cox regression models with inverse probability of treatment weighting were used to examine the associations between DAPT and outcomes. Patients who received DAPT, compared with those who received aspirin monotherapy, had a lower incidence of a composite of all-cause death, myocardial infarction, stroke, or repeat revascularization at 6 months (2.9% versus 4.2%; inverse probability of treatment weighting-adjusted hazard ratio [HR], 0.65; 95% CI, 0.55-0.77; P<0.001) as well as death (HR, 0.61; 95% CI, 0.41-0.90), myocardial infarction (HR, 0.55; 95% CI, 0.40-0.74), and stroke (HR, 0.58; 95% CI, 0.46-0.74). The incidence of major bleeding did not differ significantly between the 2 groups (HR, 1.11; 95% CI, 0.69-1.78). Similar results were noted across multiple subgroups as well as when using different analytic methods. Conclusions Among patients undergoing coronary artery bypass grafting, DAPT with clopidogrel plus aspirin as secondary prevention was associated with reduced risk of major adverse cardiovascular and cerebrovascular events within 6 months as compared with aspirin monotherapy, and there was no significant increase in major bleeding.

Anticoagulation and antiplatelet therapy post coronary artery bypass surgery

BACKGROUND

Coronary artery bypass grafting (CABG) is the gold standard treatment for patients with multivessel coronary heart disease. Although its use has proven long-term survival benefits, there is a relative degree of graft failure which increases morbidity and mortality rates.

DISCUSSION

This review discusses clinical outcomes following antiplatelet and anticoagulant therapy after CABG. There is wide variation of evidence about the use of clopidogrel or ticagrelor to aspirin postoperatively in relation to improving graft patency rates or clinical outcomes over the use of aspirin alone. These dual therapies may have significant protective effects in patients undergoing off-pump CABG. Recent studies suggest that superior outcomes may be attained by combining prasugrel with aspirin. Further research is needed to evaluate this, as well as compare the effectiveness of different dual antiplatelet regimens. There is weak evidence for post-CABG anticoagulation, with warfarin and rivaroxaban providing no protection against graft failure but decreasing long-term major adverse cardiac events. Anticoagulation seems to be indicated only in post-CABG patients at high risk of future ischemic events.

CONCLUSION

The use of dual anti-platelet therapy post coronary artery bypass surgery needs further research. Potentially, selective patient groups will benefit more from the addition of thienopyridine antiplatelets or anticoagulants to aspirin after CABG.

Bleeding complications after dual antiplatelet therapy with ticagrelor versus dual antiplatelet therapy with clopidogrel-a propensity-matched comparative study of two antiplatelet regimes in off-pump coronary artery bypass grafting

Purpose

Ticagrelor combined with aspirin had shown better saphenous vein graft patency than aspirin with clopidogrel after off-pump coronary artery bypass grafting. However, the safety of this drug in regard to bleeding complications remains unknown. The aim of our study was to assess the bleeding complications of dual antiplatelet therapy with aspirin and ticagrelor compared with aspirin and clopidogrel within the first 3 months after off-pump surgery.

Methods

Three hundred eighty-two consecutive patients who were prescribed aspirin with ticagrelor (ticagrelor group) were compared with 660 patients who received aspirin and clopidogrel (clopidogrel group). After propensity matching, 144 patients in each group were compared for bleeding events and major adverse cardiac and cerebral events. Major bleeding was defined as composite outcome of re-exploration for bleeding, any fatal bleeding, intracranial bleeding, and any bleeding requiring hospitalization.

Results

Patients in the ticagrelor group had more incidence of re-exploration for bleeding (p = 0.042), pericardial effusion requiring drainage (p = 0.007), readmissions (p < 0.01), gastrointestinal bleeding (p = 0.01), and major bleeding (5.8% vs. 2.1%, p < 0.01, OR 2.8 (1.43-5.58)). After propensity analysis, gastrointestinal bleed (p = 0.024), major bleeding (7.6% vs.1.4%, p < 0.001, OR 5.8 (1.28-26.97)), length of ICU stay (p = 0.039), and readmissions (p = 0.003, OR 11.83 (1.51-92.86)) were more in the ticagrelor group. Major adverse cardiac and cerebral events were similar between the groups.

Conclusion

Dual antiplatelet therapy with aspirin and ticagrelor increased gastrointestinal bleeding events, major bleeding events, and readmission rates compared with aspirin and clopidogrel after off-pump coronary artery bypass grafting.

Effect of Adding Ticagrelor to Standard Aspirin on Saphenous Vein Graft Patency in Patients Undergoing Coronary Artery Bypass Grafting (POPular CABG): A Randomized, Double-Blind, Placebo-Controlled Trial

BACKGROUND

Approximately 15% of saphenous vein grafts (SVGs) occlude during the first year after coronary artery bypass graft surgery (CABG) despite aspirin use. The POPular CABG trial (The Effect of Ticagrelor on Saphenous Vein Graft Patency in Patients Undergoing Coronary Artery Bypass Grafting Surgery) investigated whether ticagrelor added to standard aspirin improves SVG patency at 1 year after CABG.

METHODS

In this investigator-initiated, randomized, double-blind, placebo-controlled, multicenter trial, patients with ≥1 SVGs were randomly assigned (1:1) after CABG to ticagrelor or placebo added to standard aspirin (80 mg or 100 mg). The primary outcome was SVG occlusion at 1 year, assessed with coronary computed tomography angiography, in all patients that had primary outcome imaging available. A generalized estimating equation model was used to perform the primary analysis per SVG. The secondary outcome was 1-year SVG failure, which was a composite of SVG occlusion, SVG revascularization, myocardial infarction in myocardial territory supplied by a SVG, or sudden death.

RESULTS

Among 499 randomly assigned patients, the mean age was 67.9±8.3 years, 87.1% were male, the indication for CABG was acute coronary syndrome in 31.3%, and 95.2% of procedures used cardiopulmonary bypass. Primary outcome imaging was available in 220 patients in the ticagrelor group and 223 patients in the placebo group. The SVG occlusion rate in the ticagrelor group was 10.5% (51 of 484 SVGs) versus 9.1% in the placebo group (43 of 470 SVGs), odds ratio, 1.29 [95% CI, 0.73-2.30]; P=0.38. SVG failure occurred in 35 (14.2%) patients in the ticagrelor group versus 29 (11.6%) patients in the placebo group (odds ratio, 1.22 [95% CI, 0.72-2.05]).

CONCLUSIONS

In this randomized, placebo-controlled trial, the addition of ticagrelor to standard aspirin did not reduce SVG occlusion at 1 year after CABG. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02352402.

Differential effects of dual antiplatelet therapy in patients presented with acute coronary syndrome vs. stable ischaemic heart disease after coronary artery bypass grafting

Aims

The current study sought to evaluate whether long-term clinical outcomes according to the use of dual antiplatelet therapy (DAPT) or single antiplatelet therapy (SAPT) differed between acute coronary syndrome (ACS) and stable ischaemic heart disease (SIHD) patients who underwent coronary artery bypass grafting surgery (CABG).

Methods and results

Between January 2001 and December 2017, 3199 patients with ACS (55.3%) and 2583 with SIHD (44.7%) who underwent isolated CABG were enrolled. The study population was stratified using DAPT or SAPT in ACS patients and SIHD patients. The primary outcome was a cardiovascular death or myocardial infarction (MI) at 5 years. After CABG, DAPT was more frequently used in patients with ACS than in those with SIHD [n = 1960 (61.3%) vs. n = 1313 (50.8%), P &lt; 0.001]. Among patients with ACS, the DAPT group showed a significantly lower risk of cardiovascular death or MI at 5 years than the SAPT group [DAPT vs. SAPT, 4.0% vs. 7.8%, hazard ratio (HR) 0.521, 95% confidence interval (CI) 0.339–0.799; P = 0.003]. In contrast, among patients with SIHD, there was no significant difference in the rate of cardiovascular death or MI at 5 years between the use of DAPT and SAPT (4.0% vs. 4.0%, HR 0.991, 95% CI 0.604–1.626; P = 0.971). These findings were robust to multiple sensitivity analyses and competing risk analysis. In the subgroup analysis, the use of DAPT was associated with a significantly lower risk of cardiovascular death or MI among SIHD patients with a previous percutaneous coronary intervention (PCI), with a significant interaction between the use of DAPT and PCI history (interaction P = 0.011).

Conclusion

Among ACS patients who underwent CABG, the use of DAPT was associated with lower cardiovascular death or MI than the use of SAPT, but this was not the case in SIHD patients.

Trial registration

ClinicalTrials.gov, NCT03870815.

Development of a risk score for early saphenous vein graft failure: An individual patient data meta-analysis

OBJECTIVES

Early saphenous vein graft (SVG) occlusion is typically attributed to technical factors. We aimed at exploring clinical, anatomical, and operative factors associated with the risk of early SVG occlusion (within 12 months postsurgery).

METHODS

Published literature in MEDLINE was searched for studies reporting the incidence of early SVG occlusion. Individual patient data (IPD) on early SVG occlusion were used from the SAFINOUS-CABG Consortium. A derivation (n = 1492 patients) and validation (n = 372 patients) cohort were used for model training (with 10-fold cross-validation) and external validation respectively.

RESULTS

In aggregate data meta-analysis (48 studies, 41,530 SVGs) the pooled estimate for early SVG occlusion was 11%. The developed IPD model for early SVG occlusion, which included clinical, anatomical, and operative characteristics (age, sex, dyslipidemia, diabetes mellitus, smoking, serum creatinine, endoscopic vein harvesting, use of complex grafts, grafted target vessel, and number of SVGs), had good performance in the derivation (c-index = 0.744; 95% confidence interval [CI], 0.701-0.774) and validation cohort (c-index = 0.734; 95% CI, 0.659-0.809). Based on this model. we constructed a simplified 12-variable risk score system (SAFINOUS score) with good performance for early SVG occlusion (c-index = 0.700, 95% CI, 0.684-0.716).

CONCLUSIONS

From a large international IPD collaboration, we developed a novel risk score to assess the individualized risk for early SVG occlusion. The SAFINOUS risk score could be used to identify patients that are more likely to benefit from aggressive treatment strategies.

Ticagrelor-based antiplatelet regimens in patients treated with coronary artery bypass grafting: a meta-analysis of randomized controlled trials

OBJECTIVES

The optimal antiplatelet strategy in patients undergoing CABG remains unclear. This is the first meta-analysis investigating the clinical outcomes associated with ticagrelor-based antiplatelet regimens in patients receiving CABG.

METHODS

Relevant scientific databases were searched for studies investigating antiplatelet regimens after CABG from inception until April 1, 2019. Studies which randomly assigned CABG patients to either ticagrelor-based or control antiplatelet regimens were eligible. The primary outcome of this analysis was all-cause death. The main secondary outcome was MI. Other outcomes of interest were cardiac death, major adverse cardiac events, stroke and bleeding. This study is registered with PROSPERO, number CRD42019122192.

RESULTS

Five trials comprising 3996 patients (2002 assigned to ticagrelor-based and 1994 to control antiplatelet regimens) were eligible for quantitative synthesis. The median follow-up was 12 months. Control antiplatelet regimens consisted of either aspirin or clopidogrel or both. As compared to control, ticagrelor-based regimens reduced the risk of all-cause death [0.61 (0.43-0.87); P = 0.007], cardiac death [0.58 (0.39-0.86); P = 0.007] and major adverse cardiac events [0.79 (0.63-0.98); P = 0.03], without difference in the risk of MI [0.76 (0.50-1.18); P = 0.22], stroke [0.99 (0.56-1.78); P = 0.98] or bleeding [1.04 (0.95-1.14); P = 0.41]. There was a treatment effect modification for the primary outcome associated with trials enrolling predominantly patients with acute coronary syndrome (P for interaction = 0.038).

CONCLUSIONS

In patients receiving CABG, ticagrelor-based regimens reduce mortality and major adverse cardiac events without excess bleeding risk as compared with aspirin monotherapy or the combination of aspirin and clopidogrel. The benefit of ticagrelor-based regimens is more relevant in those studies enrolling predominantly patients with acute coronary syndrome. These findings require further confirmation in randomized trials focused on this subset of patients and powered for clinical outcomes.

Hospital Variability Drives Inconsistency in Antiplatelet Use After Coronary Bypass

BACKGROUND

Continuation of dual antiplatelet therapy (DAPT) after coronary artery bypass grafting (CABG) after acute myocardial infarction is recommended by current guidelines. We sought to evaluate guideline adherence over time and factors associated with postoperative DAPT within a regional consortium.

METHODS

Isolated CABG patients from 2011 to 2017 who had a myocardial infarction within 21 days prior to surgery were included. Patients were stratified by DAPT prescription at discharge and by time period, early (2011-2014) vs late (2015-2017). Hierarchical regressions were then performed to evaluate factors influencing DAPT use after CABG.

RESULTS

A total of 7314 patients were included with an overall rate of DAPT utilization of 31.2% that increased from 29.6% in the early to 33.4% in the late era (P < .01). There was considerable variability in hospital rates of DAPT (range 9.5%-92.1%) and hospital level changes over time (26% increased, 11% decreased, and 63% remained stable). After adjustment for clinical factors, era was not associated with DAPT use but treating hospital remained significantly associated with DAPT use. Other clinical factors associated with increased DAPT utilization included off-pump surgery (odds ratio [OR] 4.48, P < .01) and prior percutaneous coronary intervention (OR 2.02, P < .01), and atrial fibrillation (OR 0.39, P < .01) was associated with decreased utilization.

CONCLUSIONS

Dual antiplatelet use has increased between 2011 and 2017, driven primarily by evolving patient demographics. Significant hospital-level variability drives inconsistency in DAPT utilization. Efforts to promote DAPT use for patients treated with CABG after myocardial infarction in concordance with current guidelines should be targeted at the hospital level.

A randomized, double-blind, placebo-controlled trial investigating the effect of ticagrelor on saphenous vein graft patency in patients undergoing coronary artery bypass grafting surgery-Rationale and design of the POPular CABG trial

RATIONALE

An estimated 15% of saphenous vein grafts (SVGs) occlude in the first year after coronary artery bypass grafting (CABG) despite aspirin therapy. Graft occlusion can result in symptoms, myocardial infarction, and death. SVG occlusion is primarily caused by atherothrombosis, in which platelet activation plays a pivotal role. Evidence regarding the effect of stronger platelet inhibition on SVG patency after CABG is limited. The main objective of the POPular CABG trial is to determine whether dual antiplatelet therapy with aspirin plus ticagrelor improves SVG patency when compared to aspirin alone.

STUDY

The POPular CABG is a randomized, double-blind, placebo-controlled, multicenter trial investigating the effect of adding ticagrelor to standard aspirin therapy on the rate of SVG occlusion. A total of 500 patients undergoing CABG with ≥ 1 SVG are randomized to ticagrelor or placebo. The primary end point is SVG occlusion rate, assessed with coronary computed tomography angiography at 1 year. Secondary end points are stenoses and occlusions in both SVGs and arterial grafts and SVG failure at 1 year, defined as a composite of SVG occlusion on coronary computed tomography angiography or coronary angiography, SVG revascularization, myocardial infarction in the territory supplied by an SVG, or sudden death. Safety end points are bleeding events at 30 days and 1 year.

CONCLUSION

The POPular CABG trial investigates whether adding ticagrelor to standard aspirin after CABG reduces the rate of SVG occlusion at 1 year.

Antithrombotic treatment after coronary artery bypass graft surgery: systematic review and network meta-analysis

OBJECTIVE

To assess the effects of different oral antithrombotic drugs that prevent saphenous vein graft failure in patients undergoing coronary artery bypass graft surgery.

DESIGN

Systematic review and network meta-analysis.

DATA SOURCES

Medline, Embase, Web of Science, CINAHL, and the Cochrane Library from inception to 25 January 2019. ELIGIBILITY CRITERIA: for selecting studies Randomised controlled trials of participants (aged ≥18) who received oral antithrombotic drugs (antiplatelets or anticoagulants) to prevent saphenous vein graft failure after coronary artery bypass graft surgery.

MAIN OUTCOME MEASURES

The primary efficacy endpoint was saphenous vein graft failure and the primary safety endpoint was major bleeding. Secondary endpoints were myocardial infarction and death.

RESULTS

This review identified 3266 citations, and 21 articles that related to 20 randomised controlled trials were included in the network meta-analysis. These 20 trials comprised 4803 participants and investigated nine different interventions (eight active and one placebo). Moderate certainty evidence supports the use of dual antiplatelet therapy with either aspirin plus ticagrelor (odds ratio 0.50, 95% confidence interval 0.31 to 0.79, number needed to treat 10) or aspirin plus clopidogrel (0.60, 0.42 to 0.86, 19) to reduce saphenous vein graft failure when compared with aspirin monotherapy. The study found no strong evidence of differences in major bleeding, myocardial infarction, and death among different antithrombotic therapies. The possibility of intransitivity could not be ruled out; however, between-trial heterogeneity and incoherence were low in all included analyses. Sensitivity analysis using per graft data did not change the effect estimates.

CONCLUSIONS

The results of this network meta-analysis suggest an important absolute benefit of adding ticagrelor or clopidogrel to aspirin to prevent saphenous vein graft failure after coronary artery bypass graft surgery. Dual antiplatelet therapy after surgery should be tailored to the patient by balancing the safety and efficacy profile of the drug intervention against important patient outcomes.

STUDY REGISTRATION

PROSPERO registration number CRD42017065678.

Randomized trial of ticagrelor vs. aspirin in patients after coronary artery bypass grafting: the TiCAB trial

Aims

The antiplatelet treatment strategy providing optimal balance between thrombotic and bleeding risks in patients undergoing coronary artery bypass grafting (CABG) is unclear. We prospectively compared the efficacy of ticagrelor and aspirin after CABG.

Methods and results

We randomly assigned in double-blind fashion patients scheduled for CABG to either ticagrelor 90 mg twice daily or 100 mg aspirin (1:1) once daily. The primary outcome was the composite of cardiovascular death, myocardial infarction (MI), repeat revascularization, and stroke 12 months after CABG. The main safety endpoint was based on the Bleeding Academic Research Consortium classification, defined as BARC ≥4 for periprocedural and hospital stay-related bleedings and BARC ≥3 for post-discharge bleedings. The study was prematurely halted after recruitment of 1859 out of 3850 planned patients. Twelve months after CABG, the primary endpoint occurred in 86 out of 931 patients (9.7%) in the ticagrelor group and in 73 out of 928 patients (8.2%) in the aspirin group [hazard ratio 1.19; 95% confidence interval (CI) 0.87–1.62; P = 0.28]. All-cause mortality (ticagrelor 2.5% vs. aspirin 2.6%, hazard ratio 0.96, CI 0.53–1.72; P = 0.89), cardiovascular death (ticagrelor 1.2% vs. aspirin 1.4%, hazard ratio 0.85, CI 0.38–1.89; P = 0.68), MI (ticagrelor 2.1% vs. aspirin 3.4%, hazard ratio 0.63, CI 0.36–1.12, P = 0.12), and stroke (ticagrelor 3.1% vs. 2.6%, hazard ratio 1.21, CI 0.70–2.08; P = 0.49), showed no significant difference between the ticagrelor and aspirin group. The main safety endpoint was also not significantly different (ticagrelor 3.7% vs. aspirin 3.2%, hazard ratio 1.17, CI 0.71–1.92; P = 0.53).

Conclusion

In this prematurely terminated and thus underpowered randomized trial of ticagrelor vs. aspirin in patients after CABG no significant differences in major cardiovascular events or major bleeding could be demonstrated.

ClinicalTrials.gov Identifier

NCT01755520.

Impact of dual antiplatelet therapy after coronary artery bypass surgery on 1-year outcomes in the Arterial Revascularization Trial

OBJECTIVES

There is still little evidence to boldport routine dual antiplatelet therapy (DAPT) with P2Y12 antagonists following coronary artery bypass grafting (CABG). The Arterial Revascularization Trial (ART) was designed to compare 10-year survival after bilateral versus single internal thoracic artery grafting. We aimed to get insights into the effect of DAPT (with clopidogrel) following CABG on 1-year outcomes by performing a post hoc ART analysis.

METHODS

Among patients enrolled in the ART (n = 3102), 609 (21%) and 2308 (79%) were discharged on DAPT or aspirin alone, respectively. The primary end-point was the incidence of major adverse cerebrovascular and cardiac events (MACCE) at 1 year including cardiac death, myocardial infarction, cerebrovascular accident and reintervention; safety end-point was bleeding requiring hospitalization. Propensity score (PS) matching was used to create comparable groups.

RESULTS

Among 609 PS-matched pairs, MACCE occurred in 34 (5.6%) and 34 (5.6%) in the DAPT and aspirin alone groups, respectively, with no significant difference between the 2 groups [hazard ratio (HR) 0.97, 95% confidence interval (CI) 0.59-1.59; P = 0.90]. Only 188 (31%) subjects completed 1 year of DAPT, and in this subgroup, MACCE rate was 5.8% (HR 1.11, 95% CI 0.53-2.30; P = 0.78). In the overall sample, bleeding rate was higher in DAPT group (2.3% vs 1.1%; P = 0.02), although this difference was no longer significant after matching (2.3% vs 1.8%; P = 0.54).

CONCLUSIONS

Based on these findings, when compared with aspirin alone, DAPT with clopidogrel prescribed at discharge was not associated with a significant reduction of adverse cardiac and cerebrovascular events at 1 year following CABG.

Secondary prevention after coronary artery bypass graft surgery: a primer

PURPOSE OF REVIEW

Despite the benefits of surgical coronary revascularization, patients continue to be at risk for ischemic events in the years that follow coronary artery bypass graft surgery (CABG), mandating the role for postoperative secondary preventive therapy. The purpose of this review was to present a summary on the subject of secondary prevention after CABG, including an overview of a recently published scientific statement, and highlight the newest studies in the field.

RECENT FINDINGS

Aspirin and statin therapy continue to be the mainstay of secondary prevention after CABG, although newer antiplatelet and lipid-lowering medicines are being actively studied for their potential benefits. Other important elements to secondary prevention after CABG include the aggressive management of hypertension, smoking cessation, and the initiation of cardiac rehabilitation.

SUMMARY

Secondary prevention is an essential component of postoperative care after CABG. Instituting preventive therapies after surgery optimizes graft patency and helps patients achieve the highest level of physical health and quality of life following CABG.

Impact of ticagrelor versus aspirin on graft patency after CABG: Rationale and design of the TARGET (ticagrelor antiplatelet therapy to reduce graft events and thrombosis) randomized controlled trial (NCT02053909)

RATIONALE

Saphenous vein graft disease remains a major limitation of coronary artery bypass graft surgery (CABG). Up to 20% of vein grafts will occlude within the first year after CABG despite standard aspirin antiplatelet therapy. However, more potent postoperative platelet inhibition with ticagrelor may improve graft patency. The goal of this study will be to evaluate the efficacy of ticagrelor, as compared to aspirin, for the prevention of saphenous vein graft occlusion following CABG.

STUDY DESIGN

The Ticagrelor Antiplatelet Therapy to Reduce Graft Events and Thrombosis (TARGET) study is a multi-center double-blind randomized controlled trial enrolling patients who have undergone multi-vessel CABG with at least one saphenous vein graft. Patients are being randomized to receive either aspirin 81 mg twice per day or ticagrelor 90 mg twice per day for 2 years starting within 7 days after surgery. The projected enrollment is 150 patients in each arm (300 total patients). Patients will undergo computed tomography (CT) coronary angiography at 1 and 2 years after surgery to assess the incidence of vein graft occlusion and stenosis.

CONCLUSION

To our knowledge, this trial is the first prospective study to evaluate the impact of early postoperative ticagrelor on 1- and 2-year graft patency after CABG. Furthermore, it is also the first trial to use a novel antiplatelet agent as a standalone, without aspirin, after CABG. Should ticagrelor reduce the incidence of postoperative graft occlusion, the results of this study will redefine modern antiplatelet management following coronary bypass surgery (ClinicalTrials.govNCT02053909).

Consensus Document ANMCO/ANCE/ARCA/GICR-IACPR/GISE/SICOA: Long-term Antiplatelet Therapy in Patients with Coronary Artery Disease

Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 receptor inhibitor is the cornerstone of pharmacologic management of patients with acute coronary syndrome (ACS) and/or those receiving coronary stents. Long-term (>1 year) DAPT may further reduce the risk of stent thrombosis after a percutaneous coronary intervention (PCI) and may decrease the occurrence of non-stent-related ischaemic events in patients with ACS. Nevertheless, compared with aspirin alone, extended use of aspirin plus a P2Y12 receptor inhibitor may increase the risk of bleeding events that have been strongly linked to adverse outcomes including recurrent ischaemia, repeat hospitalisation and death. In the past years, multiple randomised trials have been published comparing the duration of DAPT after PCI and in ACS patients, investigating either a shorter or prolonged DAPT regimen. Although the current European Society of Cardiology guidelines provide a backup to individualised treatment, it appears to be difficult to identify the ideal patient profile which could safely reduce or prolong the DAPT duration in daily clinical practice. The aim of this consensus document is to review contemporary literature on optimal DAPT duration, and to guide clinicians in tailoring antiplatelet strategies in patients undergoing PCI or presenting with ACS.

Effect of Ticagrelor Plus Aspirin, Ticagrelor Alone, or Aspirin Alone on Saphenous Vein Graft Patency 1 Year After Coronary Artery Bypass Grafting: A Randomized Clinical Trial

IMPORTANCE

The effect of ticagrelor with or without aspirin on saphenous vein graft patency in patients undergoing coronary artery bypass grafting (CABG) is unknown.

OBJECTIVE

To compare the effect of ticagrelor + aspirin or ticagrelor alone vs aspirin alone on saphenous vein graft patency 1 year after CABG.

DESIGN, SETTING, AND PARTICIPANTS

Randomized, multicenter, open-label, clinical trial among 6 tertiary hospitals in China. Eligible patients were aged 18 to 80 years with indications for elective CABG. Patients requiring urgent revascularization, concomitant cardiac surgery, dual antiplatelet or vitamin K antagonist therapy post-CABG, and who were at risk of serious bleeding were excluded. From July 2014 until November 2015, 1256 patients were identified and 500 were enrolled. Follow-up was completed in January 2017.

INTERVENTIONS

Patients were randomized (1:1:1) to start ticagrelor (90 mg twice daily) + aspirin (100 mg once daily) (n = 168), ticagrelor (90 mg twice daily) (n = 166), or aspirin (100 mg once daily) (n = 166) within 24 hours post-CABG. Neither patients nor treating physicians were blinded to allocation.

MAIN OUTCOMES AND MEASURES

Primary outcome was saphenous vein graft patency 1 year after CABG (FitzGibbon grade A) adjudicated independently by a committee blinded to allocation. Saphenous vein graft patency was assessed by multislice computed tomographic angiography or coronary angiography.

RESULTS

Among 500 randomized patients (mean age, 63.6 years; women, 91 [18.2%]), 461 (92.2%) completed the trial. Saphenous vein graft patency rates 1 year post-CABG were 88.7% (432 of 487 vein grafts) with ticagrelor + aspirin; 82.8% (404 of 488 vein grafts) with ticagrelor alone; and 76.5% (371 of 485 vein grafts) with aspirin alone. The difference between ticagrelor + aspirin vs aspirin alone was statistically significant (12.2% [95% CI, 5.2% to 19.2%]; P < .001), whereas the difference between ticagrelor alone vs aspirin alone was not statistically significant (6.3% [95% CI, -1.1% to 13.7%]; P = .10). Five major bleeding episodes occurred during 1 year of follow-up (3 with ticagrelor + aspirin; 2 with ticagrelor alone).

CONCLUSIONS AND RELEVANCE

Among patients undergoing elective CABG with saphenous vein grafting, ticagrelor + aspirin significantly increased graft patency after 1 year vs aspirin alone; there was no significant difference between ticagrelor alone and aspirin alone. Further research with more patients is needed to assess comparative bleeding risks.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT02201771.

Antithrombotic therapy in patients receiving saphenous vein coronary artery bypass grafts: a protocol for a systematic review and network meta-analysis

INTRODUCTION

The current evidence for the prevention of saphenous vein graft failure (SVGF) after coronary artery bypass graft (CABG) surgery consists of direct head-to-head comparison of treatments (including placebo) in randomised-controlled trials (RCTs) and observational studies. However, summarising the evidence using traditional pairwise meta-analyses does not allow the inclusion of data from treatments that have not been compared head to head. Exclusion of such comparisons could impact the precision of pooled estimates in a meta-analysis. Hence, to address the challenge of whether aspirin alone or in addition to another antithrombotic agent is a more effective regimen to improve SVG patency, a network meta-analysis (NMA) is necessary. The objectives of this study are to synthesise the available evidence on antithrombotic agents (or their combination) and estimate the treatment effects among direct and indirect treatment comparisons on SVGF and major adverse cardiovascular events, and to generate a treatment ranking according to their efficacy and safety outcomes.

METHODS

We will perform a systematic review of RCTs evaluating antithrombotic agents in patients undergoing CABG. A comprehensive English literature search will be conducted using electronic databases and grey literature resources to identify published and unpublished articles. Two individuals will independently and in duplicate screen potential studies, assess the eligibility of potential studies and extract data. Risk of bias and quality of evidence will also be evaluated independently and in duplicate. We will investigate the data to ensure its suitability for NMA, including adequacy of the outcome data and transitivity of treatment effects. We plan to estimate the pooled direct, indirect and the mixed effects for all antithrombotic agents using a NMA.

ETHICS AND DISSEMINATION

Due to the nature of the study, there are no ethical concerns nor informed consent required. We anticipate that this NMA will be the first to simultaneously assess the relative effects of multiple antithrombotic agents in patients undergoing CABG. The results of this NMA will inform clinicians, patients and guideline developers the best available evidence on comparative effects benefits of antithrombotic agents after CABG while considering the side effect profile to support future clinical decision-making. We will disseminate the results of our systematic review and NMA through a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42017065678.

Comparison of Outcomes and Costs Associated With Aspirin ± Clopidogrel After Coronary Artery Bypass Grafting

Optimal antiplatelet therapy after coronary artery bypass graft (CABG) surgery remains controversial. This study evaluated the role of dual antiplatelet therapy using aspirin and clopidogrel (DAPT) versus antiplatelet therapy using aspirin only (ASA) on post-CABG clinical outcomes and costs. In the Department of Veterans Affairs Randomized On/Off Bypass (ROOBY) trial, clopidogrel use after CABG was prospectively collected beginning in year 2 of this study to include 1,525 of the 2,203 original ROOBY patients who received aspirin after CABG. Discretionarily, surgeons after CABG administered either DAPT or ASA treatments. The ROOBY trial's primary 30-day composite (mortality or perioperative morbidity), 1-year composite (all-cause death, repeat revascularization, or nonfatal myocardial infarction), and costs were compared for these 2 strategies. Of the 1,525 subjects, 511 received DAPT and 1,014 received ASA. DAPT subjects, compared with ASA subjects, had lower rates of preoperative left ventricular ejection fraction of ≥45% (78.8% vs 85.7%, p <0.001), on-pump CABG (36.6% vs 57.1%, p = 0.001), and endoscopic vein harvesting (30.0% vs 42.8%, p <0.001). ASA patients were more likely to have earlier aspirin administration and receive 325 versus 81 mg dosages. The 30-day composite outcome rate was significantly lower for DAPT patients compared with ASA patients (3.3% vs 7.1%, p = 0.003), but the 1-year composite outcome was equal between the 2 groups (12.0% vs12.0%, p = 1.0). At 1 year, there were no cost differences between the 2 groups. Propensity analyses did not significantly alter the results. In conclusion, DAPT appeared safe and was associated with fewer 30-day adverse outcomes than aspirin only and with no 1-year outcome or cost differences.

Meta-Analysis of Aspirin Versus Dual Antiplatelet Therapy Following Coronary Artery Bypass Grafting

Although aspirin monotherapy is considered the standard of care after coronary artery bypass grafting (CABG), more recent evidence has suggested a benefit with dual antiplatelet therapy (DAPT) after CABG. We performed a meta-analysis of observational studies and randomized controlled trials comparing outcomes of aspirin monotherapy with DAPT in patients after CABG. Subgroup analyses were conducted according to surgical technique (i.e., on vs off pump) and clinical presentation (acute coronary syndrome vs no acute coronary syndrome). Random effects overall risk ratios (RR) were calculated using the DerSimonian and Laird model. Eight randomized control trials and 9 observational studies with a total of 11,135 patients were included. At a mean follow-up of 23 months, major adverse cardiac events (10.3% vs 12.1%, RR 0.84, confidence interval [CI] 0.71 to 0.99), all-cause mortality (5.7% vs 7.0%, RR 0.67, CI 0.48 to 0.94), and graft occlusion (11.3% vs 14.2%, RR 0.79, CI 0.63 to 0.98) were less with DAPT than with aspirin monotherapy. There was no difference in myocardial infarction, stroke, or major bleeding between the 2 groups. In conclusion, DAPT appears to be associated with a reduction in graft occlusion, major adverse cardiac events, and all-cause mortality, without significantly increasing major bleeding compared with aspirin monotherapy in patients undergoing CABG.

Management and Prevention of Saphenous Vein Graft Failure: A Review

Coronary artery bypass grafting (CABG) remains a vital treatment for patients with multivessel coronary artery disease (CAD), especially diabetics. The long-term benefit of the internal thoracic artery graft is well established and remains the gold standard for revascularization of severe CAD. It is not always possible to achieve complete revascularization through arterial grafts, necessitating the use of saphenous vein grafts (SVG). Unfortunately, SVGs do not have the same longevity, and their failure is associated with significant adverse cardiac outcomes and mortality. This paper reviews the pathogenesis of SVG failure, highlighting the difference between early, intermediate, and late failure. It also addresses the different surgical techniques that affect the incidence of SVG failure, as well as the medical and percutaneous prevention and treatment options in contemporary practice.

Dual Antiplatelet Therapy Versus Aspirin Monotherapy in Diabetics With Multivessel Disease Undergoing CABG: FREEDOM Insights

BACKGROUND

Clinical practice guidelines recommend post-operative dual antiplatelet therapy (DAPT) in patients who undergo coronary artery bypass grafting (CABG) following acute coronary syndromes (ACS).

OBJECTIVES

The authors have evaluated DAPT utilization rates and associated outcomes among post-CABG patients with diabetes.

METHODS

In a post hoc, nonrandomized analysis from the FREEDOM (Future REvascularization Evaluation in patients with Diabetes mellitus: Optimal management of Multivessel disease) trial, we compared patients receiving DAPT (aspirin plus thienopyridine) and aspirin monotherapy at 30 days post-operatively. The primary outcome was the risk adjusted 5-year FREEDOM composite of all-cause mortality, nonfatal myocardial infarction, or stroke. Safety outcomes included major bleeding, blood transfusion, and hospitalization for bleeding.

RESULTS

At 30 days post-CABG, 544 (68.4%) patients received DAPT and 251 (31.6%) patients received aspirin alone. The median (25th, 75th percentile) duration of clopidogrel therapy was 0.98 (0.23 to 1.91) years. There was no significant difference in the 5-year primary composite outcome between DAPT- and aspirin-treated patients (12.6% vs. 16.0%; adjusted hazard ratio [HR]: 0.83; 95% confidence interval [CI]: 0.54 to 1.27; p = 0.39). The 5-year primary composite outcomes were similar for patients receiving DAPT versus aspirin monotherapy respectively, in subgroups with pre-CABG ACSs (15.2% vs. 16.5%; HR: 1.06; 95% CI: 0.53 to 2.10; p = 0.88) and those with stable angina (11.6% vs. 15.8%; HR: 0.82; 95% CI: 0.50 to 1.343; p = 0.42). The composite outcomes of both treatment groups were also similar by SYNTAX score, duration of DAPT therapy, completeness of revascularization, and in off-pump CABG. No treatment-related differences in major bleeding (5.6% vs. 5.7%; HR: 1.00; 95% CI: 0.50 to 1.99; p = 0.99), blood transfusions (4.8% vs. 4.5%; HR: 1.09; 95% CI: 0.51 to 2.34; p = 0.82), or hospitalization for bleeding (2.6% vs. 3.3%; HR: 0.85; 95% CI: 0.34 to 2.17; p = 0.74) were observed between aspirin- and DAPT-treated patients, respectively.

CONCLUSIONS

The use of DAPT in patients with diabetes post-CABG in our cohort was high. Compared with aspirin monotherapy, no associated differences were observed in cardiovascular or bleeding outcomes, suggesting that routine use of DAPT may not be clinically warranted. (Future REvascularization Evaluation in patients with Diabetes mellitus: Optimal management of Multivessel disease [FREEDOM]; NCT00086450).

Preoperative aspirin use and acute kidney injury after cardiac surgery: A propensity-score matched observational study

BACKGROUND

The association between preoperative aspirin use and postoperative acute kidney injury (AKI) in cardiovascular surgery is unclear. We sought to evaluate the effect of preoperative aspirin use on postoperative AKI in cardiac surgery.

METHODS

A total of 770 patients who underwent cardiovascular surgery under cardiopulmonary bypass were reviewed. Perioperative clinical parameters including preoperative aspirin administration were retrieved. We matched 108 patients who took preoperative aspirin continuously with patients who stopped aspirin more than 7 days or did not take aspirin for the month before surgery. The parameters used in the matching included variables related to surgery type, patient's demographics, underlying medical conditions and preoperative medications.

RESULTS

In the first seven postoperative days, 399 patients (51.8%) developed AKI, as defined by the Kidney Disease Improving Global Outcomes (KDIGO) criteria and 128 patients (16.6%) required hemodialysis. Most patients took aspirin 100 mg once daily (n = 195, 96.5%) and the remaining 75 mg once daily. Multivariable analysis showed that preoperative maintenance of aspirin was independently associated with decreased incidence of postoperative AKI (odds ratio [OR] 0.46, 95% confidence interval [CI] 0.21-0.98, P = 0.048; after propensity score matching: OR 0.39, 95% CI 0.22-0.67, P = 0.001). Preoperative maintenance of aspirin was associated with less incidence of AKI defined by KDIGO both in the entire and matched cohort (n = 44 [40.7%] vs. 69 [63.9%] in aspirin and non-aspirin group, respectively in matched sample, relative risk [RR] 0.64, 95% CI 0.49, 0.83, P = 0.001). Preoperative aspirin was associated with decreased postoperative hospital stay after matching (12 [9-18] days vs. 16 [10-25] in aspirin and non-aspirin group, respectively, P = 0.038). Intraoperative estimated or calculated blood loss using hematocrit difference and estimated total blood volume showed no difference according to aspirin administration in both entire and matched cohort.

CONCLUSIONS

Preoperative low dose aspirin administration without discontinuation was protective against postoperative AKI defined by KDIGO criteria independently in both entire and matched cohort. Preoperative aspirin was also associated with decreased hemodialysis requirements and decreased postoperative hospital stay without increasing bleeding. However, differences in AKI and hospital stay were not associated with in-hospital mortality.

A randomized, parallel group, double-blind study of ticagrelor compared with aspirin for prevention of vascular events in patients undergoing coronary artery bypass graft operation: Rationale and design of the Ticagrelor in CABG (TiCAB) trial: An Investigator-Initiated trial

BACKGROUND

For patients with coronary artery disease undergoing coronary bypass surgery, acetylsalicylic acid (ASA) currently represents the gold standard of antiplatelet treatment. However, adverse cardiovascular event rates in the first year after coronary artery bypass grafting (CABG) still exceed 10%. Graft failure, which is predominantly mediated by platelet aggregation, has been identified as a major contributing factor in this context. Therefore, intensified platelet inhibition is likely to be beneficial. Ticagrelor, an oral, reversibly binding and direct-acting P2Y12 receptor antagonist, provides a rapid, competent, and consistent platelet inhibition and has shown beneficial results compared with clopidogrel in the subset of patients undergoing bypass surgery in a large previous trial.

HYPOTHESIS

Ticagrelor is superior to ASA for the prevention of major cardiovascular events within 1 year after CABG.

STUDY DESIGN

The TiCAB trial (NCT01755520) is a multicenter, phase III, double-blind, double-dummy, randomized trial comparing ticagrelor with ASA for the prevention of major cardiovascular events within 12 months after CABG. Patients undergoing CABG will be randomized in a 1:1 fashion to either ticagrelor 90 mg twice daily or ASA 100 mg once daily. The study medication will be started within 24 hours after surgery and maintained for 12 months. The primary end point is the composite of cardiovascular death, myocardial infarction, stroke, and repeat revascularization at 12 months after CABG. The sample size is based on an expected event rate of 13% of the primary end point within the first 12 months after randomization in the control group, a 2-sided α level of .0492 (to preserve the overall significance level of .05 after planned interim analysis), a power of 0.80%, 2-sided testing, and an expected relative risk of 0.775 in the active group compared with the control group and a dropout rate of 2%. According to power calculations based on a superiority design for ticagrelor, it is estimated that 3,850 patients should be enrolled.

SUMMARY

There is clinical equipoise on the issue of optimal platelet inhibition after CABG. The TiCAB trial will provide a pivotal comparison of the efficacy and safety of ticagrelor compared with ASA after CABG.

Vein graft failure: from pathophysiology to clinical outcomes

Occlusive arterial disease is a leading cause of morbidity and mortality worldwide. Aside from balloon angioplasty, bypass graft surgery is the most commonly performed revascularization technique for occlusive arterial disease. Coronary artery bypass graft surgery is performed in patients with left main coronary artery disease and three-vessel coronary disease, whereas peripheral artery bypass graft surgery is used to treat patients with late-stage peripheral artery occlusive disease. The great saphenous veins are commonly used conduits for surgical revascularization; however, they are associated with a high failure rate. Therefore, preservation of vein graft patency is essential for long-term surgical success. With the exception of 'no-touch' techniques and lipid-lowering and antiplatelet (aspirin) therapy, no intervention has hitherto unequivocally proven to be clinically effective in preventing vein graft failure. In this Review, we describe both preclinical and clinical studies evaluating the pathophysiology underlying vein graft failure, and the latest therapeutic options to improve patency for both coronary and peripheral grafts.

Agreement of treatment effects for mortality from routinely collected data and subsequent randomized trials: meta-epidemiological survey

OBJECTIVE

To assess differences in estimated treatment effects for mortality between observational studies with routinely collected health data (RCD; that are published before trials are available) and subsequent evidence from randomized controlled trials on the same clinical question.

DESIGN

Meta-epidemiological survey.

DATA SOURCES

PubMed searched up to November 2014.

METHODS

Eligible RCD studies were published up to 2010 that used propensity scores to address confounding bias and reported comparative effects of interventions for mortality. The analysis included only RCD studies conducted before any trial was published on the same topic. The direction of treatment effects, confidence intervals, and effect sizes (odds ratios) were compared between RCD studies and randomized controlled trials. The relative odds ratio (that is, the summary odds ratio of trial(s) divided by the RCD study estimate) and the summary relative odds ratio were calculated across all pairs of RCD studies and trials. A summary relative odds ratio greater than one indicates that RCD studies gave more favorable mortality results.

RESULTS

The evaluation included 16 eligible RCD studies, and 36 subsequent published randomized controlled trials investigating the same clinical questions (with 17,275 patients and 835 deaths). Trials were published a median of three years after the corresponding RCD study. For five (31%) of the 16 clinical questions, the direction of treatment effects differed between RCD studies and trials. Confidence intervals in nine (56%) RCD studies did not include the RCT effect estimate. Overall, RCD studies showed significantly more favorable mortality estimates by 31% than subsequent trials (summary relative odds ratio 1.31 (95% confidence interval 1.03 to 1.65; I(2)=0%)).

CONCLUSIONS

Studies of routinely collected health data could give different answers from subsequent randomized controlled trials on the same clinical questions, and may substantially overestimate treatment effects. Caution is needed to prevent misguided clinical decision making.