Use of Aspirin and Clopidogrel After Coronary Artery Bypass Graft Surgery

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.

Effect of ticagrelor with or without aspirin on vein graft outcome 1 year after on-pump and off-pump coronary artery bypass grafting

Background

In the present post hoc analysis of the DACAB trial, we evaluated the effects of ticagrelor with or without aspirin on 1-year vein graft outcomes after coronary artery bypass grafting (CABG) with and without cardiopulmonary bypass (CPB) (on-pump and off-pump).

Methods

The DACAB trial was a multicenter, randomized, open-label, parallel control study enrolling 500 patients with 1,460 vein grafts undergoing CABG. For current post-hoc study, all patients in the DACAB study were included in the analysis to compare the effects of different antiplatelet regimens under on/off pump. Patients were randomly assigned to 1 of 3 antiplatelet treatment regimens (ticagrelor plus aspirin, T + A; ticagrelor alone, T; or aspirin alone, A) within 24 hours after CABG, and were stratified into on-pump and off-pump subgroups. The primary outcome was 1-year vein graft patency rate.

Results

Totally 121 patients underwent on-pump CABG (39 with 121 vein grafts in T + A, 36 with 101 vein grafts in T, and 46 with 137 vein grafts in A) and 379 patients underwent off-pump CABG (129 with 336 vein grafts in T + A, 130 with 387 vein grafts in T, and 120 with 348 vein grafts in A). Compared with A, T + A showed a higher 1-year vein graft patency rate in both on-pump (adjusted OR for non-patency =0.62, 95% CI: 0.16–2.45) and off-pump (adjusted OR for non-patency =0.35, 95% CI: 0.20–0.62) subgroups, P interaction =0.647; whereas T did not in either on-pump (adjusted OR for non-patency = 0.92, 95% CI: 0.31–2.76) or off-pump (adjusted OR for non-patency =0.58, 95% CI: 0.34–1.00) subgroups, P interaction =0.430.

Conclusions

In the DACAB trial, for patients underwent either on-pump or off-pump CABG, ticagrelor plus aspirin showed consistent benefit for achieving 1-year vein graft patency, with particular benefit being seen in the off-pump.

Care of the Post-CABG Patient

An estimated 400,000 coronary artery bypass graft operations are performed annually in the United States. Saphenous vein grafts are the most commonly used conduits; however, graft failure is common. In contrast, left internal mammary artery grafts have more favorable long-term patency rates. Guidelines recommend aggressive secondary prevention. In the 2 decades following surgery, 16% of patients require repeat revascularization, and percutaneous coronary intervention accounts for 98% of procedures performed. Post-coronary artery bypass graft patients presenting with symptoms of acute coronary syndrome or progressive heart failure should undergo early coronary angiography given the high likelihood that such a presentation represents graft failure. Percutaneous coronary intervention in degenerated saphenous vein grafts is associated with embolization that may cause the "no-reflow phenomenon," which can be avoided with the use of embolic protection devices. Hybrid revascularization procedures are a promising emerging strategy to avoid the placement of vein grafts.

Coronary endarterectomy: an old tool for patients currently operated on with coronary artery bypass grafting. Long-term results, risk factor analysis

Aim

Coronary endarterectomy (CE) may provide a useful adjunctive technique to coronary artery bypass grafting (CABG) in patients with diffuse coronary artery disease. Nevertheless, the incidence of complications still remains high, long-term results remain unclear, and no risk factors for late mortality have been completely described yet.

Material and methods

We retrospectively reviewed 90 consecutive patients (67 ±8.2 years) undergoing isolated CABG in association with CE between 2006 and 2013. Mean follow-up was 75.1 ±36.2 months (median: 84 months) and it was 100% complete (6755/6755 patient-months).

Results

Operative mortality was 4.4%, the incidence of perioperative myocardial infarction was 11%. Ten-year survival was 83.3 ±4.1%, freedom from cardiac death 92.7 ±2.9%, and freedom from major adverse cardiac and cerebrovascular events 58.2 ±10.2%. Independent predictors of late mortality were age older than 70 years at time of the surgery (p = 0.018) and chronic obstructive pulmonary disease (p = 0.036). Ten-year freedom from cardiac death was better after CE on the left descending coronary artery (LAD) (93.2 ±3.3%) in comparison to CE not on the LAD (74.6 ±10.2%), although this difference did not reach statistical significance (p = 0.102).

Conclusions

Although the incidence of perioperative myocardial infarction continues to be not negligible, in the presence of diffusely diseased coronary artery vessels CE associated with CABG appears to be a feasible adjunctive surgical tool, conferring satisfactory early and long-term outcomes. Coronary endarterectomy on the LAD confers a high probability of freedom from late cardiac death. Patients older than 70 years and those affected by a primary respiratory disease represent a new challenge on which to focus attention due to the increased risk of late death.

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.

Dual antiplatelet therapy for perioperative myocardial infarction following CABG surgery

OBJECTIVES

Perioperative myocardial infarction (MI) after coronary artery bypass graft surgery (CABG) has been associated with adverse outcome. Whether perioperative MI should be treated with dual antiplatelet therapy (DAPT) is unknown. We compared the effect of DAPT versus aspirin alone on short-term outcomes among patients with perioperative MI following CABG.

METHODS

We used data from 3 clinical trials that enrolled patients undergoing isolated CABG: PREVENT IV (2002-2003), MEND-CABG II (2004-2005), and RED-CABG (2009-2010) (n = 9117). Perioperative MI was defined as CK-MB >5 times the upper limit of normal within 24 h of surgery (n = 2052). DAPT was defined as DAPT given after surgery and prior to discharge. A Cox regression model was used to assess the association between DAPT and 30-day nonfatal MI, stroke, or mortality after adjustment for baseline covariates.

RESULTS

DAPT (n = 527) and aspirin alone (n = 1525) cohorts were similar in baseline comorbidities. Off pump bypass was used in 5.2% (n = 106) of patients. There was no difference in the 30-day composite of death, MI or stroke between patients receiving DAPT versus aspirin alone, nor in any of the individual components. There were fewer all-cause re-hospitalizations at 30 days following surgery among patients in the DAPT group (adjusted HR 0.71, CI 0.52-0.97, P = .033).

CONCLUSION

One-quarter of CABG patients who had perioperative MI were treated with DAPT. DAPT was not associated with a difference in MI, stroke, or mortality at 30 days, but was associated with fewer re-hospitalizations. Further studies are needed to determine the optimal antiplatelet regimen following perioperative MI. What is already known about this subject? Perioperative myocardial infarction portends poor outcome but optimal management is currently unclear. While dual antiplatelet therapy is standard of care for acute coronary syndrome, its role in perioperative myocardial infarction is unknown. What does this study add? Dual antiplatelet therapy use during perioperative myocardial infarction was not associated with a difference in myocardial infarction, stroke or mortality at 30 days. It was, however, associated with fewer re-hospitalizations at 30 days. How might this impact on clinical practice? Dual antiplatelet therapy may be a potential treatment option for perioperative myocardial infarction after CABG surgery. Further studies are needed to better understand treatment for this disease process.

Single versus double antiplatelet therapy in patients undergoing coronary artery bypass grafting with coronary endarterectomy: mid-term results and clinical implications

Objectives

Coronary endarterectomy (CE) represents a useful adjunctive technique to coronary artery bypass grafting (CABG) in the presence of diffuse coronary artery disease. Nevertheless, the long-term patency of the graft remains unclear, and no standard anticoagulation and antiplatelet protocols exist for use after CE. The aim of this retrospective study was to evaluate and possibly to clarify the role of single (SAT) versus dual antiplatelet therapy (DAT) at mid-term follow-up.

Methods

Between January 2006 and December 2013, CE was performed in 90 patients (mean age 67 ± 8.2 years) who also underwent isolated CABG. After surgery, 20 patients received aspirin 100 mg daily (SAT group), and 52 patients received aspirin plus clopidogrel 75 mg daily (DAT group). Clopidogrel was discontinued in the DAT group 12 months after the operation.

Results

The overall in-hospital mortality rate was 2.7% (SAT 0% vs DAT 3.8%; P = ns). Perioperative myocardial infarction was 12.3% (SAT 15.0% vs DAT 11.5%; P = ns), and major bleeding requiring surgical re-exploration was 4.1% (SAT 10.0% vs DAT 1.9%; P = ns). Mean follow-up duration was 71.3 ± 32.7 months (median 79 months), and was 100% complete (5208/5208 pt-months). At 7 years of follow-up, freedom from cardiac death was 84 ± 9% in group SAT versus 85 ± 5% in group DAT (P = ns); freedom from new percutaneous coronary intervention was 93 ± 6% versus 100% (P = ns), and freedom from major adverse cardiac and cerebrovascular events was 73 ± 10% versus 75 ± 6% (P = ns).

Conclusions

In patients with diffuse coronary disease, CE is a safe and feasible technique with acceptable mid-term results. No differences were observed in terms of major clinical outcomes between patients treated with single versus dual antiplatelet therapy at least in a mid-term period of follow-up.

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).

Should dual antiplatelet therapy be used in patients following coronary artery bypass surgery? A meta-analysis of randomized controlled trials

BACKGROUND

We assessed the effectiveness of dual antiplatelet therapy (DAPT) post elective or urgent (i.e., post acute coronary syndrome [ACS]) coronary artery bypass graft surgery (CABG).

METHODS

We systematically searched MEDLINE, EMBASE, and the Cochrane Registry from inception to August 2015. Randomized controlled trials (RCTs) in adults undergoing CABG comparing either dual vs. single antiplatelet therapy or higher- vs. lower-intensity DAPT were identified.

RESULTS

Nine RCTs (n = 4,887) with up to 1y follow-up were included. Five RCTs enrolled patients post-elective CABG (n = 986). Two multi-centre RCTs enrolled ACS patients who subsequently underwent CABG (n = 2,155). These 7 RCTs compared clopidogrel plus aspirin to aspirin alone. Two other multi-centre RCTs reported on ACS patients who subsequently underwent CABG comparing higher intensity DAPT with either ticagrelor (n = 1,261) or prasugrel (n = 485) plus aspirin to clopidogrel plus aspirin. Post-operative anti-platelet therapy was started when chest tube bleeding was no longer significant, typically within 24-48 h. There were no differences in all-cause mortality in clopidogrel plus aspirin vs. aspirin RCTs; conversely, all-cause mortality was significantly lower in ticagrelor and prasugrel vs. clopidogrel RCTs (risk ratio[RR] 0.49, 95% confidence interval[CI] 0.33-0.71, p = 0.0002; 2 RCTs, n = 1695; I(2)  = 0%; interaction p < 0.01 compared to clopidogrel plus aspirin vs aspirin RCTs). There were no differences in myocardial infarctions, strokes, or composite outcomes. Overall, major bleeding was not significantly increased (RR 1.31, 95% CI 0.81-2.10, p = 0.27; 7 RCTs, n = 4500). There was heterogeneity (I(2)   = 42%) due almost entirely to higher bleeding reported for the prasugrel RCT which included mainly CABG-related major bleeding (RR 3.15, 95% CI 1.45-6.87, p = 0.004; 1 RCT, n = 437).

CONCLUSIONS

Most RCT data for DAPT post CABG is derived from subgroups of ACS patients in DAPT RCTs requiring CABG who resume DAPT post-operatively. Limited RCT data with heterogeneous trial designs suggest that higher intensity (prasugrel or ticagrelor) but not lower intensity (clopidogrel) DAPT is associated with an approximate 50% lower mortality in ACS patients who underwent CABG based on post-randomization subsets from single RCTs. Large prospective RCTs evaluating the use of DAPT post-CABG are warranted to provide more definitive guidance for clinicians.

Water-soluble jack-knife prawn extract inhibits 5-hydroxytryptamine-induced vasoconstriction and platelet aggregation in humans

Coronary artery spasm plays an important role in the pathogenesis of various ischemic heart diseases or serious arrhythmia. The aim of this study is to look for functional foods which have physiologically active substances preventing 5-hydroxytryptamine (5-HT)-related vasospastic diseases including peri- and postoperative ischemic complications of coronary artery bypass grafting (CABG) from ocean resources in Japanese coastal waters. First, we evaluated the effect of water-soluble ocean resource extracts on the response to 5-HT in HEK293 cells which have forcibly expressed cyan fluorescent protein-fused 5-HT2A receptors (5-HT2A-CFP). Among 5 different water-soluble extracts of ocean resources, the crude water-soluble jack-knife prawn extract (WJPE) significantly reduced maximal Ca(2+) influx induced by 0.1 μM 5-HT in a concentration-dependent manner. The Crude WJPE significantly inhibited, in a concentration-dependent manner, 5-HT-induced constriction of human saphenous vein. 5-HT released from activated platelets plays a crucial roles in the constriction of coronary artery. Next the WJPE was purified for applying the experiment of 5-HT-induced human platelet aggregation. The purified WJPE significantly inhibited 5-HT-induced human platelet aggregation also in a concentration-dependent manner. Based on our findings, jack-knife prawn could be one of a functional food with health-promoting benefits for most people with vasospastic diseases including patients who have gone CABG.

Coronary artery bypass grafting: Part 2--optimizing outcomes and future prospects

Since first introduced in the mid-1960s, coronary artery bypass grafting (CABG) has become the standard of care for patients with coronary artery disease. Surprisingly, the fundamental surgical technique itself did not change much over time. Nevertheless, outcomes after CABG have dramatically improved over the first 50 years. Randomized trials comparing percutaneous coronary intervention (PCI) to CABG have shown converging outcomes for select patient populations, providing more evidence for wider use of PCI. It is increasingly important to focus on the optimization of the short- and long-term outcomes of CABG and to reduce the level of invasiveness of this procedure. This review provides an overview on how new techniques and widespread consideration of evolving strategies have the potential to optimize outcomes after CABG. Such developments include off-pump CABG, clampless/anaortic CABG, minimally invasive CABG with or without extending to hybrid procedures, arterial revascularization, endoscopic vein harvesting, intraprocedural epiaortic scanning, graft flow assessment, and improved secondary prevention measures. In addition, this review represents a framework for future studies by summarizing the areas that need more rigorous clinical (randomized) evaluation.

Clopidogrel improves aspirin response after off-pump coronary artery bypass surgery

We sought to assess the incidence of aspirin resistance after off-pump coronary artery bypass (OPCAB) surgery, and investigate whether clopidogrel can improve aspirin response and be safely applied early after OPCAB surgery. Sixty patients who underwent standard OPCAB surgery were randomized into two groups. One group (30 patients) received mono-antiplatelet treatment (MAPT) with aspirin 100 mg daily and the other group received dual antiplatelet treatment (DAPT) with aspirin 100 mg daily plus clopidogrel 75 mg daily. Platelet aggregations in response to arachidonic acid (PL_AA) and adenosine diphosphate (ADP) (PL_ADP) were measured preoperatively and on days 1 to 6, 8 and 10 after the antiplatelet agents were administered. A PL_AA level above 20% was defined as aspirin resistance. Postoperative bleeding and other perioperative variables were also recorded. There were no significant differences between the two groups in baseline characteristics, average number of distal anastomosis, operation time, postoperative bleeding, ventilation time and postoperative hospital stay. However, the incidence of aspirin resistance was significantly lower in the DAPT group than that in the MAPT group on the first and second day after antiplatelet agents were given (62.1% vs. 32.1%, 34.5% vs. 10.7%, respectively, both P < 0.05). There was no significant difference in postoperative complication between the two groups. DAPT with aspirin and clopidogrel can be safely applied to OPCAB patients early after the procedure. Moreover, clopidogrel reduces the incidence of OPCAB-related aspirin resistance.

Prehospitalization antiplatelet therapy and outcomes after saphenous vein graft intervention

Antiplatelet therapy is recommended after coronary artery bypass grafting, because it improves saphenous vein graft (SVG) patency and clinical outcomes. We investigated the association between prehospital antiplatelet regimens and outcomes after SVG intervention. Patients who underwent SVG intervention from 2003 to 2008 were divided into 3 groups: (1) no antiplatelet therapy, (2) the use of aspirin or clopidogrel, and (3) the use of dual antiplatelet therapy (DAPT) at admission. Clinical follow-up examinations were performed at 30 days and 1 year. The primary outcome was the composite of all-cause mortality, myocardial infarction, the need for revascularization, and stroke at 30 days. The relation between antiplatelet therapy and outcomes was adjusted for factors associated with the outcomes. A total of 225 patients underwent SVG intervention, 87% were men, and the mean age was 70 years. Of the 225 patients, 21 (9.4%) were not receiving antiplatelet therapy, 102 (45.3%) were receiving aspirin/clopidogrel, and 102 (45.3%) were receiving DAPT. The patients without antiplatelet therapy were more frequently women, had presented earlier after coronary artery bypass grafting, and were less frequently taking other cardiac-related medications. The patients taking aspirin or DAPT were more often smokers and had a greater peripheral vascular burden. The incidence of the 30-day and 1-year primary outcomes was greater in patients without preadmission antiplatelet use (38.1% vs 14.9% and 13.9%, overall p = 0.01; 52.4% vs 29.5% and 28.3%, overall p = 0.03). After adjustment, antiplatelet use remained associated with the primary outcome. In conclusion, prehospital use of antiplatelet therapy was associated with a lower occurrence of major adverse cardiac events after SVG intervention. We did not find that DAPT improved outcomes compared to single antiplatelet therapy.

'No-touch' saphenous vein harvesting improves graft performance in patients undergoing coronary artery bypass surgery: a journey from bedside to bench

The saphenous vein is the most commonly used conduit in patients undergoing coronary artery bypass surgery yet its patency is inferior to the internal thoracic artery. Vascular damage inflicted to the vein when using conventional harvesting techniques affects its structure. Endothelial denudation is associated with early vein graft failure while damage of the outermost vessel layers has adverse long-term effects on graft performance. While many in vitro and in vivo experimental studies aimed at improving vein graft patency have been performed to date no significant 'bench to bedside' advances have been made. Among experimental strategies employed is the use of pharmacological agents, gene targeting and external stents. A 'no-touch' technique, where the saphenous vein is removed with minimal trauma and normal architecture preserved, produces a superior graft with long term patency comparable to the internal thoracic artery. Interestingly, many experimental studies are aimed at repairing or replacing those regions of the saphenous vein damaged when harvesting conventionally. 'No-touch' harvesting is superior in coronary artery bypass patients with long-term data published 5years ago. Here we describe a 'bedside to bench' situation where the mechanisms underlying the improved performance of 'no touch' saphenous vein grafts in patients have been studied in the laboratory.