Outcomes of Coronary Artery By-Pass Grafting Under Dual Antiplatelet Therapy in ST Elevated Myocardial Infarction

Patients with recent myocardial infarction (MI) or percutaneous coronary interventions (PCI) have a higher ischemic risk in addition to perioperative bleeding risk when undergoing coronary artery bypass grafting (CABG). Data regarding preoperative dual antiplatelet therapy (DAPT) failed to create a clear recommendation. In the present study, we assessed the relationship between preoperative DAPT use and adverse outcomes, particularly in ST-elevation MI (STEMI) patients. We retrospectively analyzed 748 consecutive patients with STEMI who underwent subsequent CABG surgery. Patients were divided into 2 groups: those on DAPT up to the day before CABG and those discontinued DAPT >5 days before CABG. Predictors of in-hospital mortality and major bleeding were analyzed by multivariate analysis. Preoperative DAPT was not associated with in-hospital mortality (Odds Ratio (OR):1.81; 95% Confidence Interval (CI): .89-3.68, P = .10) and major bleeding (OR: 1.15; 95% CI: .63-2.08, P = .65) after multivariate analysis. However, glycoprotein (Gp) 2b/3a inhibitors were independently associated with higher major bleeding rates. Age, shock, and EF (ejection fraction) <30% were associated with in-hospital mortality. Previous MI, Gp 2b/3a inhibitors, and EF <30% were predictors of major bleeding. In conclusion, there were no association between pre-CABG DAPT use and in-hospital mortality and major bleeding.

Impact of preoperative dual antiplatelet therapy on bleeding complications in patients with acute coronary syndromes who undergo urgent coronary artery bypass grafting

BACKGROUND

A 5- to 7-day washout period before coronary artery bypass grafting (CABG) is recommended for patients who have recently received a thienopyridine derivative; however, data supporting this guideline recommendation are lacking in Japanese patients.

METHODS

Urgent isolated CABG was performed in 130 consecutive patients with acute coronary syndromes (ACS) (101 men; mean age, 69 years). Urgent CABG was defined as operation performed within 5 days after coronary angiography. All patients continued to receive aspirin 100mg/day. The subjects were retrospectively divided into 2 groups: 30 patients with preoperative thienopyridine (clopidogrel in 15 patients, ticlopidine in 15) exposure within 5 days [dual antiplatelet therapy (DAPT) group] and 100 patients without exposure [single antiplatelet therapy (SAPT) group].

RESULTS

Although the DAPT group had a higher proportion of patients who received perioperative platelet transfusions than the SAPT group (50% vs. 18%, p<0.001), intraoperative bleeding (median, 1100ml; interquartile range, 620-1440 vs. 920ml; 500-1100) and total drain output within 48h after surgery (577±262 vs. 543±277ml) were similar. CABG-related major bleeding, which was defined as type 4 or 5 bleeding according to the Bleeding Academic Research Consortium definitions, occurred in a significantly higher proportion of patients in the DAPT group than in the SAPT group (20% vs. 3%, p=0.005). This difference in major bleeding was driven mainly by the higher rate of transfusion of ≥5U red blood cells within a 48-h period in the DAPT group (13% vs. 1%, p=0.01). There was no significant difference in the 30-day composite endpoint including death, myocardial (re)infarction, ischemic stroke, and refractory angina between the DAPT group and SAPT group (17% vs. 19%).

CONCLUSIONS

Preoperative DAPT increases the risk of CABG-related major bleeding in Japanese patients with ACS undergoing urgent CABG.

Optimal anticoagulation during off pump coronary artery bypass in patients recently exposed to clopidogrel

PURPOSE

The aim of this study was to find an optimal range of activated clotting time (ACT) during off-pump coronary artery bypass surgery (OPCAB) yielding ischemic protection without the risk of hemorrhagic complications in patients with recent exposure to dual antiplatelet therapy.

MATERIALS AND METHODS

Three hundred and five patients who received aspirin and clopidogrel within 7 days of isolated multi-vessel OPCAB were retrospectively studied. Combined hemorrhagic and ischemic outcome was defined as the occurrence of 1 of the following: significant perioperative bleeding (>30% of estimated blood volume), transfusion of packed red blood cell (pRBC) ≥ 2 U, or myocardial infarction (MI). This was compared in relation to the tertile distribution of the time-weighted average ACT-212-291 sec (first tertile), 292-334 sec (second tertile), 335-485 sec (third tertile).

RESULTS

The amount of perioperative blood loss was 937 ± 313 mL, 1014 ± 340 mL, and 1076 ± 383 mL, respectively (p=0.022). Significantly more patients in the third tertile developed MI (4%, 4%, and 12%, respectively, p=0.034). The incidence of significant perioperative blood loss and transfusion of pRBC ≥ 2 U were lower in the first tertile than those of other tertiles without statistical significance. In the multivariate analysis, the first tertile was associated with a 52% risk reduction of combined hemorrhagic and ischemic outcomes (95% confidence interval: 0.25-0.92, p= 0.027).

CONCLUSION

A lower degree of anticoagulation with a reduced initial heparin loading dose should be carefully considered for patients undergoing OPCAB who have recently been exposed to clopidogrel.

Time from adenosine di-phosphate receptor antagonist discontinuation to coronary bypass surgery in patients with acute coronary syndrome: meta-analysis and meta-regression

BACKGROUND

Adenosine di-phosphate receptor antagonists (ADPRAs) blunt hemostasis for several days after administration. This effect, aimed at preventing cardiac ischemic complications particularly in patients with acute coronary syndromes (ACS), may increase perioperative bleeding in the case of cardiac surgery. Practice Guidelines recommend withholding ADPRAs for at least 5days prior to surgery, though with a weak base of evidence. The purpose of this study was to systematically review observational and experimental studies of early or late preoperative discontinuation of ADPRAs prior to coronary artery bypass grafting (CABG) for patients with ACS.

METHODS

MEDLINE, EMBASE, the Cochrane Library databases up to December 2011; and reference lists. Observational and experimental studies that compared early ADPRA discontinuation with late discontinuation, or no discontinuation, in patients with ACS undergoing CABG.

RESULTS

There were 19 studies, including 14,046 participants, 395 deaths and 309 reoperations due to bleeding. ADPRA late discontinuation up to CABG was associated with an increased risk of postoperative mortality (OR 1.46, 95% confidence interval (CI) 1.10 to 1.93) and reoperations due to bleeding (OR 2.18; 95% CI 1.47 to 2.62). Between-study heterogeneity was low. Meta-analysis limited to high quality or prospective studies gave consistent results. In most instances, the 95% prediction intervals for summary risk estimates confirmed the risk across study groups.

CONCLUSIONS

ADPRA late discontinuation prior to CABG is associated with an increased risk of death and reoperations due to bleeding in patients with ACS. The confidence in the estimates of risk for late discontinuation is moderate to high.

Clopidogrel dilemma for orthopaedic surgeons

BACKGROUND

Patients medicated with clopidogrel who require orthopaedic surgery present a particular challenge. Whether in an emergency or elective situation the orthopaedic surgeon must balance the risks of ceasing clopidogrel versus the risk of increased bleeding that dual antiplatelet therapy generates.

METHOD

This paper reviews the current published evidence regarding the risks of continuing clopidogrel, the risks of discontinuing clopidogrel and associated considerations such as venous thromboprophylaxis.

RESULTS

Little good quality evidence exists in regard to perioperative clopidogrel for orthopaedic surgery. Available evidence across non-cardiac and cardiac surgery were assessed and presented in regards to current practices, blood loss for orthopaedic operations, risks when continuing clopidogrel, risks of stopping clopidogrel and also the consideration of venous thromboembolism.

CONCLUSIONS

The patients at greatest risk, when discontinuing clopidogrel therapy, are those with drug eluting stents who may be at risk of stent thrombosis. Where possible, efforts should be made to continue clopidogrel therapy through the perioperative period, taking precautions to minimize bleeding. If the risk of bleeding is too high, antiplatelet therapy must be reinstated as soon as considered reasonable after surgery. In addition, patients on clopidogrel who sustain a fall or other general trauma need to be carefully assessed because of the possibility of occult bleeding, such as into the retroperitoneal space. Until more definitive evidence becomes available, this review aims to provide a guide for the orthopaedic surgeon in dealing with the difficult dilemma of the patient on clopidogrel therapy, recommending that orthopaedic surgeons take a team approach to assess the individual risks for all patients and consider continuation of clopidogrel therapy perioperatively where possible.

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.

Effect of tranexamic acid on transfusion requirement in dual antiplatelet-treated anemic patients undergoing off-pump coronary artery bypass graft surgery

BACKGROUND

Anemia is not rare in patients presenting for coronary artery bypass graft surgery (CABG) and as these patients are frequently on dual antiplatelet therapy (DAPT), the coexisting conditions could potentially increase the risk of bleeding and transfusion. The aim of this study was to evaluate the effect of tranexamic acid (TA) on blood loss and transfusion in preoperatively anemic patients who continued DAPT until within 5 days of off-pump CABG (OPCAB).

METHODS AND RESULTS

Seventy-six anemic patients were randomized into 2 groups: TA group receiving TA (1g bolus followed by infusion at 200mg/h) and a Control group receiving the same volume of saline. The amount of blood loss and transfusion requirement during, and at 4 and 24h after the operation were assessed. Patients' characteristics and operative data were similar between the groups. During the perioperative period, which combined the intraoperative and postoperative 24h data, the TA group received significantly smaller amounts of packed red blood cells and fresh frozen plasma. Total amount of perioperative blood loss was similar between the groups, although the blood loss during the postoperative 4h was significantly less in the TA group.

CONCLUSIONS

TA infusion could reduce the amount of transfusion during the perioperative period in patients with preoperative anemia who continue DAPT until within 5 days of OPCAB.

Peri-operative management of antiplatelet therapy in patients with coronary artery disease: joint position paper by members of the working group on Perioperative Haemostasis of the Society on Thrombosis and Haemostasis Research (GTH), the working group on Perioperative Coagulation of the Austrian Society for Anesthesiology, Resuscitation and Intensive Care (ÖGARI) and the Working Group Thrombosis of the European Society for Cardiology (ESC)

An increasing number of patients suffering from cardiovascular disease, especially coronary artery disease (CAD), are treated with aspirin and/or clopidogrel for the prevention of major adverse events. Unfortunately, there are no specific, widely accepted recommendations for the perioperative management of patients receiving antiplatelet therapy. Therefore, members of the Perioperative Haemostasis Group of the Society on Thrombosis and Haemostasis Research (GTH), the Perioperative Coagulation Group of the Austrian Society for Anesthesiology, Reanimation and Intensive Care (ÖGARI) and the Working Group Thrombosis of the European Society of Cardiology (ESC) have created this consensus position paper to provide clear recommendations on the perioperative use of anti-platelet agents (specifically with semi-urgent and urgent surgery), strongly supporting a multidisciplinary approach to optimize the treatment of individual patients with coronary artery disease who need major cardiac and non-cardiac surgery. With planned surgery, drug eluting stents (DES) should not be used unless surgery can be delayed for ≥12 months after DES implantation. If surgery cannot be delayed, surgical revascularisation, bare-metal stents or pure balloon angioplasty should be considered. During ongoing antiplatelet therapy, elective surgery should be delayed for the recommended duration of treatment. In patients with semi-urgent surgery, the decision to prematurely stop one or both antiplatelet agents (at least 5 days pre-operatively) has to be taken after multidisciplinary consultation, evaluating the individual thrombotic and bleeding risk. Urgently needed surgery has to take place under full antiplatelet therapy despite the increased bleeding risk. A multidisciplinary approach for optimal antithrombotic and haemostatic patient management is thus mandatory.

The causes and outcomes of inadequate implementation of existing guidelines for antiplatelet treatment in patients with acute coronary syndrome: the experience from Taiwan Acute Coronary Syndrome Descriptive Registry (T-ACCORD Registry)

BACKGROUND

Benefits of antiplatelet agents in preventing future cardiovascular events have been well established. However, the prescription pattern of antiplatelet usage in patients with acute coronary syndrome (ACS) is rarely investigated. Hence, Taiwan ACute CORonary Syndrome Descriptive Registry (T-ACCORD Registry) aimed to evaluate medical practices in Taiwan in managing ACS patients.

HYPOTHESIS

The guidelines of antiplatelet treatment is not properly implanted in the management of ACS patients.

METHODS

This prospective observational study was performed between April 2004 and December 2006 in 27 hospitals in Taiwan. A total of 1331 patients with unstable angina or non-ST-elevation myocardial infarction (NSTEMI) discharged from hospitals was analyzed.

RESULTS

The patients with older age, lower hemoglobin levels, or previous cardiovascular ischemic diseases were less likely to receive aspirin at discharge, whereas patients with NSTEMI were less likely to receive clopidogrel at discharge. The prescription of dual antiplatelet agents declined rapidly from 61.8% at discharge to 12.6% at 12 months. The most common reason for clopidogrel discontinuation was recorded as physician's judgment. Dual antiplatelet treatment for 9 months or longer was associated with lower 1-year mortality. Percutaneous coronary intervention (PCI) was the only factor leading to dual antiplatelet therapy for at least 9 months.

CONCLUSIONS

Our registry showed that underlying medical conditions may affect antiplatelet prescriptions at discharge. During the first year following an ACS episode, the prescription rate of dual antiplatelet therapy declined over time, mainly due to physician's judgment leading to the discontinuation of clopidogrel. Adherence to dual antiplatelet treatment was associated with lower total mortality at 1 year.

Developments in antiplatelet therapy for acute coronary syndromes and considerations for long-term management

OBJECTIVE

This article reviews the currently available antiplatelet therapies and emerging investigational drugs in the treatment of acutecoronary syndrome (ACS), and considerations for primary and secondary prevention in the long-term management of ACS patients undergoing percutaneous coronary intervention (PCI).

RESEARCH DESIGN AND METHODS

Primary studies and reviews in the peer-reviewed, English-language literature were identified through searches of MEDLINE (1966-2008) using the terms 'acute coronary syndrome', 'antiplatelet', 'aspirin', 'long-term management', 'P2Y(12) receptor', and 'thienopyridine'. Additional references were obtained by searching the reference lists of the identified articles. Articles were included if they were recently published and pertinent, patient-focused, and authors were recognized as leaders in the field. Current review is limited by literature search on single database.

RESULTS

Platelets play a major role in atherogenesis and the formation of thrombi, the main events in the pathogenesis of ACS. Although aspirin is an effective antiplatelet agent, efficacy and safety data from a number of randomized clinical trials on atherothrombotic disease support the use of dual antiplatelet therapies such as aspirin and thienopyridines over single antiplatelet therapy for ACS and up to 1 year following ACS. Antiplatelet agents reduce, but do not eliminate, ischemic events after ACS due, in part, to variable individual response (or resistance) in antiplatelet agents, non-compliance, progression of atherosclerosis, modest inhibition of platelet aggregation (IPA) levels and other factors. Several antiplatelet agents, including novel P2Y(12)-receptor antagonists and thrombin-receptor antagonists, are currently under investigation for ACS and primary and secondary prevention in the long-term management of patients undergoing PCI.

CONCLUSIONS

Current antiplatelet therapies have clinical benefits such as reducing immediate and long-term cardiovascular risk, but substantial residual risk remains indicating a need for new therapeutic agents. Additional large randomized trials are necessary to determine the most appropriate treatment regimens for ACS patients.