Aspirin and clopidogrel use in the early postoperative period following on-pump and off-pump coronary artery bypass grafting

Role of Antiplatelet Therapy in Patients with Severe Coronary Artery Disease Undergoing Coronary Artery Endarterectomy within Coronary Artery Bypass Surgery

Background—Coronary endarterectomy (CEA) has been introduced to allow revascularization in end-stage coronary artery disease (CAD). After CEA, the injured remnants of the vessel’s media could result in fast neo intimal tissue ingrowth, which require an anti-proliferation agent (antiplatelet therapy (APT). We aimed to review outcomes of patients undergoing CEA within bypass surgery who received either single-APT (SAPT) or dual-APT (DAPT). Methods—We retrospectively evaluated 353 consecutive patients undergoing CEA within isolated coronary artery bypass grafting (CABG) in the period 01/2000–07/2019. After surgery, patients received either SAPT (n = 153), or DAPT (n = 200) for six months then lifelong SAPT. Endpoints included early, late survival, and freedom from major-adverse-cardiac and cerebrovascular events (MACCE), which were defined as incidence of stroke, myocardial infarction, need for coronary intervention (PCI or CABG) or death for any cause. Results—Patients’ mean age was 67 ± 9.3 years; they were predominantly male 88.1%. Both DAPT- and SAPT-groups had the same extent of CAD (mean SYNTAX-Score-II: 34.1 ± 11.6 vs. 34.4 ± 17.2, p = 0.91). Postoperatively, no difference between DAPT- and SAPT-groups was reported in the incidence of low-cardiac-output syndrome (5% vs. 9.8%, p = 0.16), revision for bleeding (5% vs. 6.5% p = 0.64), 30-day mortality (4.5% vs. 5.2%, p = 0.8) or MACCE (7.5% vs. 11.8%, p = 0.19). Imaging follow-up reported significantly higher CEA and total grafts patency (90% vs. 81.5% and 95% vs. 81%, p = 0.017) in DAPT patients. Late outcomes within 97.4 ± 67.4 months show lower incidence of overall mortality (19 vs. 51%, p < 0.001) and MACCE (24.5 vs. 58.2%, p < 0.001) in the DAPT patients when compared with SAPT patients. Conclusions—Coronary endarterectomy allows revascularization in end-stage CAD when the myocardium is still viable. The use of dual APT after CEA for at least six months seems to improve mid-to-long-term patency rates and survival, and reduced the incidence of major adverse cardiac and cerebrovascular events.

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.

Ticagrelor versus aspirin 2 years after coronary bypass: Observational analysis from the TARGET trial

BACKGROUND

Compared to conventional aspirin therapy, ticagrelor did not improve vein graft patency 1 year after coronary bypass surgery (CABG) in the ticagrelor antiplatelet therapy to reduce graft events and thrombosis (TARGET) trial. However, it is unknown whether ticagrelor may impact graft patency long-term following surgery.

METHODS

In the TARGET multicenter trial, 250 CABG patients were randomized to aspirin 81 mg or ticagrelor 90 mg twice daily. In this observational analysis, 2 years after surgery, vein graft occlusion and clinical events were compared among subjects who agreed to a second year of double-blind study drug administration (N = 156).

RESULTS

Two-year graft assessment was performed for 142 patients (80 aspirin patients, 62 ticagrelor patients, 425 total grafts), with an overall 2-year graft occlusion rate of 10.6%. Vein graft occlusion at 2 years, the primary outcome of this study, did not significantly differ between the two groups (15.7% vs. 13.2%, aspirin vs. ticagrelor, p = .71). The incidence of vein grafts with any disease (stenosis or occlusion) did not significantly differ between the groups (19.4% vs. 19.8%, aspirin vs. ticagrelor, p = 1.00), and the number of patients with vein graft disease did not significantly differ between the groups (30.0% vs. 29.0%, aspirin vs. ticagrelor, p = 1.00). Vein grafts developing new disease did not significantly differ between the two groups (1.5% vs. 3.8%, aspirin vs. ticagrelor, p = .41). Freedom from major adverse cardiovascular events at 2 years was similar between the groups (p = .75).

CONCLUSION

Compared to conventional aspirin therapy, ticagrelor did not significantly reduce vein graft disease 2 years after CABG.

Commentary: Prevention of saphenous vein graft disease remains elusive

One-year outcomes of Ticagrelor Antiplatelet Therapy to Reduce Graft Events and Thrombosis (TARGET), a randomized double-blinded clinical trial comparing post-coronary artery bypass surgery antiplatelet therapy with ticagrelor versus aspirin are published in this issue of the Journal. Although the authors did not detect statistically significant differences in their primary outcome (saphenous vein graft patency at 1 year) and major adverse cardiovascular events, their findings must be interpreted with caution given important limitations in the design and execution of the trial.

Ticagrelor versus aspirin and vein graft patency after coronary bypass: A randomized trial

BACKGROUND

Antiplatelet therapy prevents saphenous vein graft (SVG) occlusion and improves outcomes after coronary artery bypass graft surgery (CABG). However, the optimal postoperative antiplatelet regimen remains unclear. The goal of the Ticagrelor Antiplatelet Therapy to Reduce Graft Events and Thrombosis (TARGET) trial was to assess whether early postoperative ticagrelor reduces SVG occlusion compared to conventional aspirin therapy.

METHODS

In this multi-center double-blind randomized trial, 250 patients who had CABG with SVG were randomized to receive either aspirin 81 mg twice daily or ticagrelor 90 mg twice daily. The primary outcome was SVG occlusion at 1 year.

RESULTS

Altogether, 123 patients were randomized to aspirin and 127 received ticagrelor. One-year graft assessment was performed in 202 patients (80.8%), examining 588 grafts, yielding an overall graft occlusion rate of 10.9%. The primary outcome, SVG occlusion at 1 year, did not significantly differ between the two groups (17.4% vs. 13.2%, aspirin vs. ticagrelor, p = .30). The incidence of vein grafts with any disease (stenosis or occlusion) did not significantly differ between the groups (21.5% vs. 22.3%, aspirin vs. ticagrelor, p = .90), and the number of patients with vein graft disease did not significantly differ between the groups (29.4% vs. 28.0%, aspirin vs. ticagrelor, p = .88). Freedom from major adverse cardiovascular events at 1 year was similar between the groups (p = .60).

CONCLUSIONS

Compared to conventional aspirin therapy, ticagrelor did not significantly reduce vein graft occlusion 1 year after CABG. Further study will assess the impact of ticagrelor on 2-year graft patency for this cohort.

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.

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.

Is administration of dual-antiplatelet therapy beneficial for patients following off-pump coronary artery bypass grafting?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether administration of dual-antiplatelet therapy (DAPT) following off-pump coronary artery bypass grafting (OPCAB) would improve postoperative clinical outcomes or minimize the incidence of postoperative graft failure. In total, 101 papers were found using the reported search, 14 of which represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. One meta-analysis and 3 randomized controlled trials showed that DAPT following OPCAB is associated with decreased incidence of saphenous vein graft occlusion. One randomized controlled trial and 4 observational studies showed no effect of DAPT on mortality following OPCAB, whereas 3 observational studies showed that DAPT decreased mortality. One meta-analysis and 4 observational studies showed that DAPT reduced the incidence of cardiac events following OPCAB. One randomized controlled trial and 4 observational studies showed that DAPT did not increase the incidence of major or minor bleeding complications following OPCAB. The results presented suggest that administration of DAPT in patients following OPCAB for at least 3 months improves saphenous vein graft patency and could be protective against recurrence of cardiac events, especially acute coronary syndrome, in comparison with aspirin monotherapy. The administration of DAPT following OPCAB is safe and is not associated with increased incidence of major or minor bleeding complications when compared with aspirin alone.

Effect of Routine Clopidogrel Use on Bleeding Complications After Endobronchial Ultrasound-guided Fine Needle Aspiration

BACKGROUND

Endobronchial ultrasonography has proven to be highly sensitive and specific in the diagnoses of patients with mediastinal and hilar adenopathy. Many of these patients are on a combination of clopidogrel (a compound that inhibits adenosine diphosphate-induced platelet aggregation) and aspirin due to neurological and/or cardiac-related comorbidities, and stopping anticoagulation may place these patients at high risk for potential complications. Our group has previously showed that thoracentesis with an 8-french catheter is safe in patients receiving clopidogrel and aspirin with low risk of complications. In this manuscript, we report the outcomes of the largest prospective multicenter series of patients undergoing endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) while receiving clopidogrel.

METHODS

Patients presenting to our institutions with mediastinal/hilar adenopathy, requiring EBUS-TBNA, and actively taking clopidogrel and aspirin were included in the study. If the medication could be held for 5 to 7 days before the procedure, the patient was excluded. EBUS-TBNA was performed by an interventional pulmonology faculty on a total of 42 patients. All patients received total intravenous anesthesia, and a total of 92 nodes were sampled. First, 3 passes were performed with a 22-G needle. If no complications were encountered, we followed with additional 3 passes with a 21 G. Rapid onsite evaluation was performed in all patients. Bleeding at the puncture site was considered significant if it required cold saline, topical sympathomimetic, or balloon tamponade for hemostasis. Bleeding was considered nonsignificant if no interventions were required to achieve hemostasis.

RESULTS

We were able to perform all procedures successfully using both the 21 and 22-G needles. One patient required 30 mL cold saline installation to accomplish hemostasis with the 21 and 22-G needles. Our yield was comparable with the current literature. No statistically significant complications occurred during the procedure. All patients were contacted within 24 hours, and none reported bloody sputum.

CONCLUSION

We suggest that EBUS-TBNA, using 22 and 21-G needles, is safe with high yields in patients with mediastinal/hilar adenopathy, actively taking clopidogrel and aspirin, and are at high risk for thrombotic complications if the medication is discontinued.

Clopidogrel versus Ticagrelor for Secondary Prevention after Coronary Artery Bypass Grafting

We sought to evaluate the outcomes of postoperative three-month dual antiplatelet therapy in patients with non-ST-elevation acute coronary syndrome (NSTE-ACS) following off-pump coronary artery bypass grafting (OPCAB) with exclusively arterial grafts. Between 2013–2016, dual antiplatelet therapy (DAPT) with either aspirin + clopidogrel (ASA + CPD group, n = 100) or aspirin + ticagrelor (ASA + TCG group, n = 169) was prescribed postoperatively in 269 NSTE-ACS patients after total arterial OPCAB. Patients with indications for other oral anticoagulants were excluded from the study. Three-month DAPT was completed in 259 patients (96%); ASA + CPD group (n = 94) vs. ASA + TCG group (n = 165). A one-to-one propensity score matching was performed. Unadjusted comparison between the groups showed no significant difference in overall survival (P = 0.253) and composite outcome of major adverse cerebrovascular and cardiovascular event (MACCE) and major bleeding (P = 0.276). The rate of freedom from composite outcome at one year in the ASA + CPD and ASA + TCG groups was 91 ± 3% and 93 ± 2%, respectively. In multivariable analysis, being in the ASA + TCG group did not increase the risk of the composite outcome of MACCE and major bleeding (P = 0.972, hazard ratio: 1.0, 95% confidence interval: 0.4–2.3). Propensity score-matched comparison (76 pairs) showed no significant difference in the overall survival (P = 0.423) and composite outcome between the groups (P = 0.442). In the setting of exclusive arterial grafting, post-OPCAB three-month DAPT showed acceptable outcomes in patients with NSTE-ACS. There was no significant difference in overall survival or composite outcome of MACCE and major bleeding between the ASA + CPD and ASA + TCG groups.

Dual antiplatelet therapy versus aspirin monotherapy in diabetics with stable ischemic heart disease undergoing coronary artery bypass grafting

Background

Dual antiplatelet therapy (DAPT) in patients presenting with acute coronary syndrome (ACS) undergoing CABG is recommended to prevent recurrent ischemic events. The benefit of DAPT post-CABG in patients with stable ischemic heart disease (SIHD) is unknown. The aim of this study was to evaluate the utilization rate of DAPT and associated outcomes in patients with SIHD undergoing CABG via a secondary analysis of Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial data.

Methods

In a post-hoc, nonrandomized analysis from the BARI 2D trial, we compared patients receiving DAPT and aspirin monotherapy within 90 days post-randomization. The primary outcome was the risk adjusted 5-year composite of all-cause mortality, nonfatal myocardial infarction (MI), or stroke. We analyzed patients assigned to prompt CABG treatment arm including both the insulin therapy assignments.

Results

Of 378 patients, within 90 days post-randomization, 59 (16%) patients received DAPT and 319 (84%) patients received aspirin alone. Cox proportional hazard analysis demonstrated that there was no significant difference in the 5-year composite event of death, MI, and stroke between DAPT and monotherapy cohorts [13 (22.0%) vs. 61 (19.1%); adjusted hazard ratio (HR): 1.06; 95% confidence interval (CI): 0.56 to 2.00; P=0.86]. There also was no significant difference at 1 year in the composite event [6 (10.2%) vs. 30 (9.4%); HR: 1.13; 95% CI: 0.46 to 2.79; P=0.79].

Conclusions

The use of DAPT in patients with diabetes post-CABG in this cohort was low. Compared with aspirin monotherapy, no associated differences were observed in cardiovascular outcomes. Larger prospective studies are needed to further elucidate this observation.

Review of risk factors, treatment, and prevention of saphenous vein graft disease after coronary artery bypass grafting

Saphenous vein graft disease (SVGD) is a type of vascular disease that may develop after coronary artery bypass grafting (CABG). SVGD seriously affects the short-term and long-term effects of CABG and increases the incidence of major adverse cardiovascular events. It is very important to identify patients at greatest risk and carry out prevention and treatment measures to determine the risk factors for SVGD. Many factors contribute to SVGD when the vein is grafted into an arterial environment, such as surgery-related factors, smoking, diabetes mellitus, hyperlipidemia, and others. In this review, we discuss the risk factors for SVGD, current surgical and pharmacologic therapies with which to manage SVGD, and the prevention of SVGD.

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).

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.

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.

Dual Antiplatelet Therapy After Coronary Artery Bypass Grafting in the Setting of Acute Coronary Syndrome

After acute coronary syndrome (ACS), dual antiplatelet therapy (DAPT) is the standard of care for both invasive management with percutaneous intervention and noninvasive (medical) management. Conversely, studies using dual antiplatelet in the population of patients presenting with ACS who undergo coronary artery bypass grafting (CABG) are conflicting. The appropriate antiplatelet regimen after CABG remains an area of controversy. Plaque stability, prevention of graft closure, and secondary thrombosis form the basis for using a second antiplatelet drug, whereas the additional risk of bleeding and lack of conclusive evidence should also be considered. After an extensive literature search, 12 clinical trials with efficacy outcomes were identified. Most of the studies are retrospective, nonrandomized single-center trials. A few large patient populations have been examined using database information. To date, there is only 1 prospective, multicenter, randomized trial published. Recommendations from national guidelines differ, proposing single antiplatelet therapy with aspirin or DAPT with the combination of aspirin and clopidogrel. The purpose of this report is to review the available clinical trial data and provide guidance to practitioners when caring for this patient population. In conclusion, there is no clear consensus regarding the use of DAPT in patients after CABG. If not contraindicated, it is reasonable to use DAPT, starting in the postoperative period, in patients presenting with ACS. Large, multicenter, randomized clinical trials are needed to definitively investigate the role of DAPT in patients with ACS after CABG.

Relationship between postoperative clopidogrel use and subsequent angiographic and clinical outcomes following coronary artery bypass grafting

Dual antiplatelet therapy with both aspirin and clopidogrel is increasingly used after coronary artery bypass grafting (CABG); however, little is known about the safety or efficacy. We sought to determine the relationship between postoperative clopidogrel and clinical and angiographic outcomes following CABG. We evaluated 3,014 patients from PREVENT IV who underwent CABG at 107 US sites. Postoperative antiplatelet therapy was left to physician discretion. Risk-adjusted angiographic and clinical outcomes were compared in patients taking and not taking clopidogrel 30 days post-CABG. At 30 days, 633 (21%) patients were taking clopidogrel. Clopidogrel users were more likely to have peripheral vascular (15 vs. 11%) and cerebrovascular disease (17 vs. 11%), prior myocardial infarction (MI) (46 vs. 41%), and off-pump surgery (33 vs. 18%). Clopidogrel use was associated with statistically insignificant higher graft failure (adjusted odds ratio 1.3; 95% confidence interval [CI] [1.0, 1.7]; P = 0.05). At 5-year follow-up, clopidogrel use was associated with similar composite rates of death, MI, or revascularization (27 vs. 24%; adjusted hazard ratio 1.1; 95% CI [0.9, 1.4]; P = 0.38) compared with those not using clopidogrel. There was an interaction between use of cardiopulmonary bypass and clopidogrel with a trend toward lower 5-year clinical events with clopidogrel in patients undergoing off-pump CABG. In this observational analysis, clopidogrel use was not associated with better 5-year outcomes following CABG. There may be better outcomes with clopidogrel among patients having off-pump surgery. Adequately powered randomized clinical trials are needed to determine the role of dual antiplatelet therapy after CABG.

Effect of routine clopidogrel use on bleeding complications after ultrasound-guided thoracentesis

BACKGROUND

Thoracentesis is one of the most commonly performed medical procedures with an excellent safety profile. Clopidogrel (a compound that inhibits adenosine diphosphate-induced platelet aggregation) is often prescribed for primary or secondary prevention of cardiovascular disease and has been associated with bleeding complications in patients undergoing surgical procedures. The purpose of this study was to assess the safety of ultrasound (US)-guided thoracentesis in patients receiving clopidogrel therapy.

METHODS

Data were collected on 30 consecutive patients taking clopidogrel without other known underlying coagulation problems. These patients underwent 45 US-guided thoracenteses over 26 months. Clopidogrel was not discontinued before the thoracentesis in patients presenting with symptomatic pleural effusion. Thoracenteses were performed in these patients and the incidence of bleeding and other complications among patients was reported.

RESULTS

Between June 2009 and August 2011, there were 30 consecutive patients on clopidogrel at the time of thoracenteses. These patients presented with respiratory distress because of pleural effusion and underwent a total of 45 thoracenteses. There was no significant bleeding or other complications in this patient population. No patient required transfusion after the procedure.

CONCLUSION

Patients who are receiving clopidogrel and present with symptomatic pleural effusion can safely undergo US-guided thoracentesis without interrupting clopidogrel before the procedure. Larger studies are required to confirm these results.

Dual anti-platelet therapy after coronary artery bypass grafting: is there any benefit? A systematic review and meta-analysis

BACKGROUND

Anti-platelet therapy is an important component of medical therapy post coronary artery bypass grafting (CABG). While aspirin administration is a Class I indication after CABG, the benefit of concomitant clopidogrel is a controversial issue.

METHODS

We searched OVID Medline, Cochrane, Scopus, and EMBASE for randomized control trials and observational studies comparing aspirin ± placebo to aspirin + clopidogrel after CABG.

RESULTS

Eleven articles (five randomized control trials and six observational studies) including 25,728 patients met inclusion criteria. Early saphenous vein graft occlusion was reduced with the use of dual anti-platelet therapy (risk ratio (RR) = 0.59, 95% CI 0.43-0.82, p = 0.02). In-hospital or 30-day mortality was lower with aspirin + clopidogrel (0.8%) compared to aspirin alone (1.9%) (p < 0.0001), while risk of angina or perioperative myocardial infarction was comparable (RR = 0.60, 95% CI 0.31-1.14, p = 0.12). Patients treated with aspirin + clopidogrel demonstrated a trend towards a higher incidence of major bleeding episodes as compared to patients treated with aspirin alone (RR = 1.17, 95% CI 1.00-1.37, p = 0.05). In a pooled analysis of studies involving off-pump CABG compared to aspirin alone, dual anti-platelet therapy reduced the risk of perioperative myocardial infarction and saphenous graft occlusion by 68% (47% to 71%) and 55% (2% to 79%) respectively.

CONCLUSION

Dual anti-platelet therapy after CABG improved early saphenous vein graft patency, but may increase the risk of bleeding. The use of dual anti-platelet therapy appears to be most beneficial in patients undergoing off-pump CABG. Prospective randomized studies are necessary to determine whether this beneficial effect of dual therapy is also achieved in patients undergoing on pump CABG.

Use of Aspirin and Clopidogrel After Coronary Artery Bypass Graft Surgery

Objective:

To evaluate the evidence for the use of dual antiplatelet therapy (DAPT) with aspirin and Clopidogrel following coronary artery bypass graft (CABG) surgery.

Data Sources:

Literature was accessed through PubMed (1950-November 2011), EMBASE (1976-November 2011), and the Cochrane databases using the terms Clopidogrel and coronary artery bypass graft. Citations from available articles were used for additional references and ClinicalTrials.gov was accessed for abstracts of ongoing studies.

Study Selection Ano Data Extraction:

Peer-reviewed studies that evaluated DAPT use after CABQ surgery in adult humans were assessed for inclusion.

Data Synthesis:

Four randomized clinical trials evaluating surrogate end points and 9 studies (3 subgroup analyses, 6 observational) evaluating clinical outcomes were reviewed. Three clinical trials assessing surrogate end points failed to demonstrate an improvement in graft patency with DAPT use, while 1 clinical trial found an increase in graft patency. As for clinical outcomes, 1 subgroup analysis demonstrated that the benefit of DAPT post-CABG after a non-ST-elevation acute coronary syndrome diminished following surgery, while an observational study demonstrated a trend toward decreased mortality. In post-CABG patients who did not experience acute coronary syndrome, 2 subgroup analyses proved inconclusive and an observational study found DAPT use to be associated with reducing in-hospital mortality, while another observational study was not associated with reduced long-term mortality. Three observational studies in off-pump CABG patients showed that DAPT use was feasible.

Conclusions:

Evidence for DAPT use following CABG is limited to subgroup analyses, observational studies, and trials with surrogate end points. The majority of clinical trials have failed to demonstrate an improvement in graft patency with DAPT. Current evidence does not support the use of DAPT to improve graft patency, and more evidence from randomized controlled trials assessing clinical outcomes is necessary to make definitive recommendations.

Effects of preoperative aspirin on cardiocerebral and renal complications in non-emergent cardiac surgery patients: a sub-group and cohort study

BACKGROUND AND OBJECTIVE

Postoperative cardiocerebral and renal complications are a major threat for patients undergoing cardiac surgery. This study was aimed to examine the effect of preoperative aspirin use on patients undergoing cardiac surgery.

METHODS

An observational cohort study was performed on consecutive patients (n = 1879) receiving cardiac surgery at this institution. The patients excluded from the study were those with preoperative anticoagulants, unknown aspirin use, or underwent emergent cardiac surgery. Outcome events included were 30-day mortality, renal failure, readmission and a composite outcome--major adverse cardiocerebral events (MACE) that include permanent or transient stroke, coma, perioperative myocardial infarction (MI), heart block and cardiac arrest.

RESULTS

Of all patients, 1145 patients met the inclusion criteria and were divided into two groups: those taking (n = 858) or not taking (n = 287) aspirin within 5 days preceding surgery. Patients with aspirin presented significantly more with history of hypertension, diabetes, peripheral arterial disease, previous MI, angina and older age. With propensity scores adjusted and multivariate logistic regression, however, this study showed that preoperative aspirin therapy (vs. no aspirin) significantly reduced the risk of MACE (8.4% vs. 12.5%, odds ratio [OR] 0.585, 95% CI 0.355-0.964, P = 0.035), postoperative renal failure (2.6% vs. 5.2%, OR 0.438, CI 0.203-0.945, P = 0.035) and dialysis required (0.8% vs. 3.1%, OR 0.230, CI 0.071-0.742, P = 0.014), but did not significantly reduce 30-day mortality (4.1% vs. 5.8%, OR 0.744, CI 0.376-1.472, P = 0.396) nor it increased readmissions in the patients undergoing cardiac surgery.

CONCLUSIONS

Preoperative aspirin therapy is associated with a significant decrease in the risk of MACE and renal failure and did not increase readmissions in patients undergoing non-emergent cardiac surgery.

Risk is not our business: safety of thoracic surgery in patients using antiplatelet therapy

American Heart Association recommendations have changed preoperative management of patients with antiplatelet therapy (APT). We assessed safety and outcomes of surgery in patients who were receiving APT. A prospective study of patients operated on while receiving APT was matched with those with no APT (ratio 1:4), using the propensity score method. Logistic regression analysis was used to identify covariates among imbalanced baseline patient variables. Both χ(2) test and Fisher's test were used to calculate the probability value for the comparison of dichotomous variables. Between January 2008 and December 2010, 38 patients who received APT at the time of surgery were matched with 141 patients who had not received APT. APT indications were a history of myocardial infarction, coronary artery by-pass graft and/or valve replacement (19), coronary artery stent (11) and severe peripheral vascular disease (8). None of the patients required re-operation for bleeding. Two patients received blood transfusions. The amount of chest tube drainage was not statistically significantly different. There were no statistically significant differences between the outcomes for the operative time, length of hospital stay, estimated blood loss or morbidity. The results show that thoracic surgical procedures can safely be performed in patients receiving APT at the time of surgery, with no increased risk of bleeding or morbidity and no differences in the operative time and the length of hospital stay.

Use of clopidogrel post-coronary artery bypass surgery in canadian patients with acute coronary syndromes

BACKGROUND

Randomized trials have established the efficacy of clopidogrel in acute coronary syndromes (ACS). The benefit of clopidogrel has also been observed in the subgroup of ACS patients who subsequently undergo coronary artery bypass surgery (CABG); however, this therapy is discontinued preoperatively and the frequency with which clopidogrel is restarted post-CABG is unknown.

METHODS

We examined the pattern of clopidogrel use in the Canadian Global Registry of Acute Coronary Events (GRACE), GRACE2, and CANRACE (2003-2008) post-CABG ACS patients. We stratified the patients according to whether they underwent CABG during their index hospitalization for ACS and whether they were prescribed clopidogrel at discharge.

RESULTS

Among those patients in whom clopidogrel status at discharge was known, 5904 (60%) of 9841 were discharged from hospital on clopidogrel. Use of clopidogrel at discharge was observed in 2222 (40.8%) of 5443 patients who were medically managed (ie, did not undergo percutaneous coronary intervention [PCI] or CABG) and in 3585 (90.1%) of 3980 patients who underwent in-hospital PCI. Overall, 455 (3.3%) of 13,776 patients underwent CABG during the index hospitalization; 255 (56%) patients were started on clopidogrel during the first 24 hours, and 66 of these patients (25.9%) were discharged on clopidogrel. In contrast, 5681 (61.3%) of the 9262 patients who did not undergo in-hospital CABG were discharged on clopidogrel.

CONCLUSIONS

Although current guidelines recommend the use of clopidogrel post-CABG in patients with ACS, our observations suggest that only 1 in 4 or 5 Canadian patients are discharged on this therapy.

Aspirin plus clopidogrel versus aspirin alone after coronary artery bypass grafting: the clopidogrel after surgery for coronary artery disease (CASCADE) Trial

BACKGROUND

clopidogrel inhibits intimal hyperplasia in animal studies and therefore may reduce saphenous vein graft (SVG) intimal hyperplasia after coronary artery bypass grafting. The Clopidogrel After Surgery for Coronary Artery DiseasE (CASCADE) study was undertaken to evaluate whether the addition of clopidogrel to aspirin inhibits SVG disease after coronary artery bypass grafting, as assessed at 1 year by intravascular ultrasound.

METHODS AND RESULTS

in this double-blind phase II trial, 113 patients undergoing coronary artery bypass grafting with SVGs were randomized to receive aspirin 162 mg plus clopidogrel 75 mg daily or aspirin 162 mg plus placebo daily for 1 year. The primary outcome was SVG intimal hyperplasia (mean intimal area) as determined by intravascular ultrasound at 1 year. Secondary outcomes were graft patency, major adverse cardiovascular events, and major bleeding. One-year intravascular ultrasound and coronary angiography were performed in 92 patients (81.4%). At 1 year, SVG intimal area did not differ significantly between the 2 groups (4.1 ± 2.0 versus 4.5 ± 2.1 mm(2), aspirin-clopidogrel versus aspirin-placebo, P=0.44). Overall 1-year graft patency was 95.2% in the aspirin-clopidogrel group compared with 95.5% in the aspirin-placebo group (P=0.90), and SVG patency was 94.3% in the aspirin-clopidogrel group versus 93.2% in the aspirin-placebo group (P=0.69). Freedom from major adverse cardiovascular events at 1 year was 92.9 ± 3.4% in the aspirin-clopidogrel group and 91.1 ± 3.8% in the aspirin-placebo group (P=0.76). The incidence of major bleeding at 1 year was similar for the 2 groups (1.8% versus 0%, aspirin-clopidogrel versus aspirin-placebo, P=0.50).

CONCLUSIONS

compared with aspirin monotherapy, the combination of aspirin plus clopidogrel did not significantly reduce the process of SVG intimal hyperplasia 1 year after coronary artery bypass grafting.

General thoracic surgery is safe in patients taking clopidogrel (Plavix)

BACKGROUND

The objective of this study was to assess the safety of general thoracic surgery in patients taking antiplatelet (clopidogrel) therapy.

METHODS

A prospective study was conducted of consecutive patients who underwent general thoracic surgery and who were taking clopidogrel perioperatively. They were matched using a propensity score from our prospective database of 11,768 patients. Intraoperative and postoperative outcomes were compared.

RESULTS

Between January 2009 and April 2010 there were 33 patients on clopidogrel at the time of surgery and 132 controls. The most common procedures were thoracotomy with lobectomy in 11 patients (robotic in 1), video-assisted wedge resection in 6, mediastinoscopy in 4, and Ivor Lewis esophagogastrectomy in 2. Epidurals were not used. There was no intraoperative morbidity or bleeding in primary thoracotomy; however, 2 of the 4 patients who underwent redo thoracotomy had bleeding that required transfusions. None of the 8 patients receiving clopidogrel who had a coronary artery stent and underwent lobectomy had a perioperative myocardial infarction whereas 5 of the 14 control patients undergoing lobectomy who had a coronary artery stent did (P = .05). Otherwise, morbidity, mortality, and length of stay were no different.

CONCLUSIONS

Patients who are receiving clopidogrel and who have a coronary artery stent placed can safely undergo general thoracic surgery. The widely held belief that surgery cannot be performed without bleeding is untrue. This new finding not only eliminates much of the preoperative dilemma posed by these patients but also may reduce their risk of a postoperative myocardial infarction. However, patients who require a redo thoracotomy may be at increased risk of bleeding.