Antiplatelet therapy in the perioperative period

The current practice of withdrawing aspirin 7-10 days preoperatively may be dangerous in certain groups of patients. The risk of cardiovascular events increases 3-fold after aspirin withdrawal. The average time between aspirin withdrawal and the manifestation of acute coronary syndrome is 8 to 11 days. The withdrawal of clopidogrel earlier than 4-6 weeks after bare metal stent implantation or less than 12 months after drug-eluting stent implantation is very risky and poses a high risk of stent thrombosis and high perioperative mortality. Continuing aspirin perioperatively leads to a 1.5-fold increase in perioperative bleeding complications but it does not lead to a higher severity of bleeding complications or higher mortality. The article analyzes current European and American guidelines for perioperative antiplatelet treatment and suggests an algorithm based on the guidelines to help make clinical decisions.     

阿司匹林在心血管病一级预防的地位

阿司匹林作为急性心肌梗死和冠心病二级预防的基础药物已得到广泛认可,然而近年来关于阿司匹林对心血管疾病的一级预防依然存在争议。阿司匹林可降低心脑血管事件的发生率,但同时又可增加出血事件。如何将其合理地运用在心血管疾病一级预防中使更多的患者获益是临床工作者的一大难题。越来越多的大规模临床研究表明阿司匹林作为心血管疾病一级预防药物的关键在于把握危险分层,进一步评价患者的状况,规范使用阿司匹林将会有效地减少心血管疾病的风险。与此同时国外许多指南及我国专家的共识均能指导医生在心血管疾病一级预防中规范地运用阿司匹林。     

Coronary syndromes following aspirin withdrawal: a special risk for late stent thrombosis

OBJECTIVES: We sought to determine whether aspirin withdrawal is an encountered situation in coronary disease patients who relapsed. BACKGROUND: Despite the recognized benefits of aspirin in coronary disease, and because of the threat of bleeding or poor compliance, aspirin intake is sometimes stopped. It is not known whether withdrawal of aspirin can be harmful in coronary-disease patients. METHODS: Between September 1999 and April 2002, a total of 1,236 patients hospitalized for acute coronary syndrome (ACS) were questioned in order to determine whether aspirin intake had been interrupted. RESULTS: Fifty-one of these ACSs occurred within 1 month after aspirin withdrawal. This represents 4.1% of all coronary events but 13.3% of recurrences. Among those patients who relapsed, the incidence of ST-segment elevation ACS was higher in those who stopped aspirin when compared to the 332 patients who did not stop aspirin (39% vs. 18%; p = 0.001). Ten (20%) cases involved a thrombosis of an uncoated stent implanted on average 15.5 +/- 6.5 months previously. Mean delay between aspirin withdrawal and the acute coronary event was 10 +/- 1.9 days. Reasons for aspirin withdrawal included minor surgery in 7 cases, fibroscopy in 8 cases, dental treatment in 13 cases, bleeding in 3 cases, and patient non-compliance in 20 cases. CONCLUSIONS: Our results support the hypothesis that aspirin withdrawal in coronary patients may represent a real risk for the occurrence of a new coronary event. Many cases involved late uncoated-stent thrombosis. Assessment of the exact incidence of coronary recurrences after aspirin withdrawal will need prospective studies.     

Application of U.S. guidelines in other countries: aspirin for the primary prevention of cardiovascular events in Japan

PURPOSE: Clinical guidelines developed in the United States are used frequently in other countries without assessment of their appropriateness in non-U.S. populations. We explored the relevance of recent U.S. guidelines for the use of aspirin for the primary prevention of cardiovascular events in the Japanese population. METHODS: From a systematic search of published data, estimates were derived for rates of coronary heart disease, hemorrhagic stroke, and major gastrointestinal bleeding for the Japanese population and for subgroups with different risk factors. Odds ratios derived from meta-analyses were used to assess the potential benefits and risks of aspirin use. RESULTS: The estimated incidence of coronary heart disease in middle-aged men in Japan is lower than in the United States (1.57 vs. 6.0 per 1000 person-years), while that of hemorrhagic stroke is higher (1.14 vs. 0.37 per 1000 person-years). Because of higher baseline rates of hemorrhagic diseases, the expected reduction in cardiovascular events with aspirin use would be offset by a greater increase in hemorrhagic complications for women and most men in Japan, except for those with both hypertension and diabetes. To achieve the same 2:1 ratio of coronary heart disease events avoided to hemorrhagic events caused that is implied by the 3% threshold for 5-year coronary disease risk in U.S. guidelines, a 6% to 14% risk threshold, depending on patient age, seems appropriate for recommending aspirin in Japanese patients. CONCLUSION: The thresholds of antiplatelet therapy for Asian populations should be two to five times higher than those for the U.S. population because of higher risks of hemorrhagic complications. The assumptions and implications of U.S. guidelines should be evaluated before use in other countries.     

Optimal drug therapy after aspirin-induced upper gastrointestinal bleeding

Upper gastrointestinal bleeding is a common adverse effect of chronic aspirin treatment. Traditionally, most physicians might tend to discontinue aspirin therapy after related gastrointestinal bleeding. However, recent studies have shown that continuation of aspirin is beneficial because of a decrease of cardiovascular complications and only a relatively small increase of recurrent peptic ulcer bleeding when combined with a proton pump inhibitor. There might be individual cases where the burden of recurrent gastrointestinal complications outweighs the risk of vascular events. In these cases the physician needs to carefully consider other precipitating factors for the recurrent gastrointestinal symptoms. At the moment, alternative antiplatelet therapy does not lead to lower gastrointestinal risks. In the near future, therapies with a more favorable profile might emerge.     

Antiplatelet agents in cardiovascular disease

Despite improvements in the treatment of acute coronary syndromes (ACS), cardiovascular disease remains the leading cause of death in the United States. Antiplatelet agents, such as aspirin and clopidogrel, play an important role in the treatment of patients with ACS, particularly those at high risk for whom treatment may yield the greatest benefits. The main challenge in preventing and managing ACS is to tailor treatment for each patient by taking into consideration patient characteristics, comorbidities, underlying short- and long-term risk factors, ischemic and bleeding risks, and expected individual responses to different medications. Several new alternatives providing more rapid and consistent platelet inhibition than aspirin and clopidogrel have been introduced for routine treatment of patients with ACS. These new treatments seem to provide additional benefits without a significant increase in the risk of bleeding, if used for the appropriate patients. In this article, we review the new antiplatelet agents being developed as well as their pharmacological characteristics, potential clinical indications, and key interactions with other antithrombotic drugs.     

Calcium, phosphorus, cardiovascular events and all-cause mortality in hemodialysis patients: a single-center retrospective cohort study to reassess the validity of the Japanese Society for Dialysis Therapy guidelines

Mineral and bone disorders frequently cause cardiovascular complications and mortality in hemodialysis patients, but few observational studies of Japanese patients have investigated this matter. A retrospective cohort study of 99 patients (53 males, 46 females; mean age: 65 +/- 12 year; 38% with diabetes mellitus) on maintenance hemodialysis in our dialysis center was conducted. Mean serum Ca, P and intact parathyroid hormone (iPTH) levels were 9.2 +/- 0.9 mg/dL, 6.1 +/- 1.7 mg/dL, and 233 +/- 333 pg/mL, respectively. The cutoff values for each of these three parameter were defined according to the target ranges recommended by the Japanese Society for Dialysis Therapy (JSDT) guidelines (Ca: 8.4-10.0 mg/dL; P: 3.5-6.0 mg/dL; iPTH: 60-180 pg/mL). During a 45-month follow up, patients with all parameters outside the target ranges showed the highest incidence of cardiovascular events and all-cause deaths (16.6 and 29.2 per 1000 person-years, respectively). The relative risks of cardiovascular events and all-cause deaths were analyzed by multivariate Cox regression models. The hazard ratio (HR) for cardiovascular events was significantly lower for patients who achieved serum Ca and P objectives compared with others (HR: 2.12; 95% CI: 1.04-4.34; P < 0.05), and similar differences were observed for all-cause deaths (HR: 3.10; 95% CI: 1.13-8.53; P < 0.05). However, the relationship between iPTH levels and each of the endpoints was less pronounced. The results of this study provide support for the JSDT guidelines, which give priority to the control of serum Ca and P levels over the control of parathyroid function.     

Aspirin and prevention of cardiovascular risk

PURPOSE: Aspirin, a potent platelet inhibitor, is widely used in patients with cardiovascular diseases. Platelet aggregation is the cornerstone of acute atherothrombotic complications. ACTUALITIES: Aspirin showed significant benefits when administered in patients with acute myocardial infarction or unstable angina, and also when used for secondary prevention in patients with known coronary artery disease. Aspirin has been evaluated in primary prevention, with interesting results in high-risk patients. Finally, aspirin can be used in some patients with supraventricular arrhythmias or with mechanical valves. PERSPECTIVES: Further investigation concerning the exact role of aspirin in primary prevention is currently being done. The association of aspirin with new antiplatelet agents in patients with acute coronary syndromes has shown interesting results.     

Acetylsalicylic acid in patients with planned (elective) interventions on the coronary arteries. Risks and benefits

In a review of the literature describes the risks and benefits of surgical interventions, in particular, coronary artery bypass grafting in patients with coronary artery disease receiving antiplatelet therapy with no cancellation or late withdrawal of acetylsalicylic acid (ASA). The data supporting a moderate - without increasing the frequency of reoperation and blood transfusion - an increased risk of perioperative bleeding in cases where operations are conducted against a background of aspirin therapy. At the same time showed a significant reduction in the risk of perioperative cardiovascular complications and improve survival after intervention, which did not occur before the removal of the drug ASA.     

Clinical relevance of clopidogrel-proton pump inhibitors interaction

Clopidogrel is a widely used antiplatelet agent for the secondary prevention of cardiovascular events in patients with stable coronary heart disease, acute coronary syndromes and ischemic stroke. Even though clopidogrel is safer than aspirin in terms of risk for gastrointestinal(GI) bleeding, the elderly, and patients with a history of prior GI bleeding, with Helicobacter pylori infection or those who are also treated with aspirin, anticoagulants, corticosteroids or nonsteroidal antiinflammatory drugs are at high risk for GI complications when treated with clopidogrel. Accordingly, proton pump inhibitors are frequently administered in combination with clopidogrel to reduce the risk for GI bleeding. Nevertheless, pharmacodynamic studies suggest that omeprazole might attenuate the antiplatelet effect of clopidogrel. However, in observational studies, this interaction does not appear to translate into increased cardiovascular risk in patients treated with this combination. Moreover, in the only randomized, double-blind study that assessed the cardiovascular implications of combining clopidogrel and omeprazole, patients treated with clopidogrel/omeprazole combination had reduced risk for GI events and similar risk for cardiovascular events than patients treated with clopidogrel and placebo. However, the premature interruption of the study and the lack of power analysis in terms of the cardiovascular endpoint do not allow definite conclusions regarding the cardiovascular safety of clopidogrel/omeprazole combination. Other proton pump inhibitors do not appear to interact with clopidogrel. Nevertheless, given the limitations of existing observational and interventional studies, the decision to administer proton pump inhibitors to patients treated with clopidogrel should be individualized based on the patient’s bleeding and cardiovascular risk.     

Bleeding complications associated with combinations of aspirin, thienopyridine derivatives, and warfarin in elderly patients following acute myocardial infarction

BACKGROUND: Combinations of aspirin with thienopyridine derivatives (clopidogrel bisulfate or ticlopidine hydrochloride) and/or warfarin sodium are increasingly being used in various cardiac conditions. However, little is known about the bleeding risks associated with these combinations, particularly in elderly individuals at the population level. This study estimates the bleeding risks associated with combinations of aspirin, thienopyridine derivatives, and warfarin in elderly patients. METHODS: We conducted a population-based observational cohort study using linked administrative databases. A total of 21,443 elderly survivors of acute myocardial infarction between 1996 and 2000 were studied. Patients were divided into 5 groups according to drug exposure: aspirin alone, warfarin alone, aspirin plus a thienopyridine derivative (antiplatelet combination), aspirin plus warfarin (anticoagulant combination), and aspirin plus warfarin plus a thienopyridine derivative (3-drug combination). Hospitalizations for bleeding events were examined. RESULTS: Hospitalizations for bleeding were observed in 1428 patients (7%). Compared with rates of patients receiving aspirin alone (0.03 per patient-year), rates of bleeding were higher among patients receiving the antiplatelet combination (0.07 per patient-year), the anticoagulant combination (0.08 per patient-year), and the 3-drug combination (0.09 per patient-year). Compared with aspirin alone, the adjusted odds ratios (95% confidence intervals) for bleeding were 1.65 (1.02-2.73) for patients receiving the antiplatelet combination and 1.92 (1.28-2.87) for patients receiving the anticoagulant combination. Only 1 of 141 patients in the 3-drug combination group had a bleeding event. CONCLUSION: In practice, antiplatelet and anticoagulant combinations lead to modest increases in bleeding risk in elderly patients, but the overall risk is small.     

Effect of aspirin on mortality in the primary prevention of cardiovascular disease

Objective

The lack of a mortality benefit of aspirin in prior meta-analyses of primary prevention trials of cardiovascular disease has contributed to uncertainty about the balance of benefits and risks of aspirin in primary prevention. We performed an updated meta-analysis of randomized controlled trials of aspirin to obtain best estimates of the effect of aspirin on mortality in primary prevention.

Methods

Eligible articles were identified by searches of electronic databases and reference lists. Outcomes of interest were all-cause mortality, cardiovascular mortality, myocardial infarction, stroke, and bleeding. Data were pooled from individual trials using the DerSimonian-Laird random-effects model, and results are presented as relative risk (RR) and 95% confidence intervals (CIs).

Results

Nine randomized controlled trials enrolling 100,076 participants were included. Aspirin reduced all-cause mortality (RR 0.94; 95% CI, 0.88-1.00), myocardial infarction (RR 0.83; 95% CI, 0.69-1.00), ischemic stroke (RR 0.86; 95% CI, 0.75-0.98), and the composite of myocardial infarction, stroke, or cardiovascular death (RR 0.88; 95% CI, 0.83-0.94), but did not reduce cardiovascular mortality (RR 0.96; 95% CI, 0.84-1.09). Aspirin increased the risk of hemorrhagic stroke (RR 1.36; 95% CI, 1.01-1.82), major bleeding (RR 1.66; 95% CI, 1.41-1.95), and gastrointestinal bleeding (RR 1.37; 95% CI, 1.15-1.62). A lack of availability of patient-level data precluded exploration of benefits and risks of aspirin in key subgroups.

Conclusion

Aspirin prevents deaths, myocardial infarction, and ischemic stroke, and increases hemorrhagic stroke and major bleeding when used in the primary prevention of cardiovascular disease.     

Aspirin in the primary prevention of cardiovascular disease: Current knowledge and future research needs

In secondary prevention, among a very wide range of survivors of prior occlusive cardiovascular disease (CVD) events and those suffering acute myocardial infarction (MI) or occlusive stroke, aspirin decreases risks of MI, stroke, and CVD death. In these high risk patients, the absolute benefits are large and absolute risks are far smaller so aspirin should be more widely prescribed. In contrast, in primary prevention, aspirin reduces risks of first MI but the evidence on stroke and CVD death remain inconclusive. Based on the current totality of evidence from predominantly low risk subjects where the absolute benefits is low and side effects the same as in secondary prevention, any decision to prescribe aspirin for primary prevention should be an individual clinical judgment by the healthcare provider that weighs the absolute benefit in reducing the risk of a first MI against the absolute risk of major bleeding. If the ongoing trials of intermediate risks subjects show net benefits then general guidelines may be justified with several caveats. First, any decision to use aspirin should continue to be made by the healthcare provider. Second, therapeutic lifestyle changes and other drugs of life saving benefit such as statins should be considered with aspirin as an adjunct, not alternative. The more widespread and appropriate use of aspirin in primary prevention is particularly attractive, especially in developing countries where CVD is emerging as the leading cause of death. In addition, aspirin is generally widely available over the counter and is extremely inexpensive.     

Primer: managing NSAID-induced ulcer complications--balancing gastrointestinal and cardiovascular risks

Ulcer complications associated with the use of NSAIDs, in high-risk patients, are often caused by a failure to identify patients' risk factors, concomitant use of aspirin or multiple NSAIDs, and underutilization of gastroprotective agents. Current data suggest that cyclo-oxygenase 2 (COX2) inhibitors and some nonselective NSAIDs increase the risk of myocardial infarction. Physicians must, therefore, take into account both the gastrointestinal and the cardiovascular risks of individual patients when prescribing NSAIDs. In patients with a low cardiovascular risk, NSAIDs can be prescribed according to the level of gastrointestinal risk. Patients with a moderate gastrointestinal risk (one or two risk factors) should receive a COX2 inhibitor or an NSAID plus a PPI or misoprostol. Patients with more than two gastrointestinal risk factors or prior ulcer complications require the combination of a COX2 inhibitor and a PPI. Patients with a high cardiovascular risk (e.g. coronary heart disease or an estimated 10-year cardiovascular risk greater than 10%) should receive prophylactic aspirin and combination therapy with a PPI or misoprostol irrespective of the presence of gastrointestinal risk factors. Naproxen is the preferred NSAID because it is not associated with excess cardiovascular risk. Patients with a high cardiovascular risk and a very high gastrointestinal risk should avoid using NSAIDs or COX2 inhibitors.     

Antiplatelet drugs: mechanisms and risks of bleeding following cardiac operations

Preoperative antiplatelet drug use is common in patients undergoing coronary artery bypass grafting (CABG). The impact of these drugs on bleeding and blood transfusion varies. We hypothesize that review of available evidence regarding drug-related bleeding risk, underlying mechanisms of platelet dysfunction, and variations in patient response to antiplatelet drugs will aid surgeons as they assess preoperative risk and attempt to limit perioperative bleeding. The purpose of this review is to (1) examine the role that antiplatelet drugs play in excessive postoperative blood transfusion, (2) identify possible mechanisms to explain patient response to antiplatelet drugs, and (3) formulate a strategy to limit excessive blood product usage in these patients. We reviewed available published evidence regarding bleeding risk in patients taking preoperative antiplatelet drugs. In addition, we summarized our previous research into mechanisms of antiplatelet drug-related platelet dysfunction. Aspirin users have a slight but significant increase in blood product usage after CABG (0.5 U of nonautologous blood per treated patient). Platelet adenosine diphosphate (ADP) receptor inhibitors are more potent antiplatelet drugs than aspirin but have a half-life similar to aspirin, around 5 to 10 days. The American Heart Association/American College of Cardiology and the Society of Thoracic Surgeons guidelines recommend discontinuation, if possible, of ADP inhibitors 5 to 7 days before operation because of excessive bleeding risk, whereas aspirin should be continued during the entire perioperative period in most patients. Individual variability in response to aspirin and other antiplatelet drugs is common with both hyper- and hyporesponsiveness seen in 5 to 25% of patients. Use of preoperative antiplatelet drugs is a risk factor for increased perioperative bleeding and blood transfusion. Point-of-care tests can identify patients at high risk for perioperative bleeding and blood transfusion, although these tests have limitations. Available evidence suggests that multiple blood conservation techniques benefit high-risk patients taking antiplatelet drugs before operation. Guidelines for patients who take aspirin and/or thienopyridines before cardiac procedures include some or all of the following: (1) preoperative identification of high-risk patients using point-of-care testing; (2) withdrawal of aspirin or other antiplatelet drugs for a few days and delay of operation in patients at high risk for bleeding if clinical circumstances permit; (3) selective perioperative use of evidence-based blood conservation interventions (e.g., short-course erythropoietin, off-pump procedures, and use of intraoperative blood conservation techniques), especially in high-risk patients; and (4) platelet transfusions if clinical bleeding occurs.     

Role of clopidogrel in managing atherothrombotic cardiovascular disease

Aspirin is the most widely used antiplatelet agent for preventing and treating vascular events. The thienopyridine derivatives, ticlopidine and clopidogrel, are a suitable alternative in patients who are intolerant to aspirin, and clopidogrel exhibits better tolerability than ticlopidine. The available evidence from randomized trials indicates that dual therapy with clopidogrel and aspirin is modestly but significantly more effective than aspirin in preventing serious vascular events. It is also associated with a favorable benefit-risk profile in patients at high risk (especially in acute coronary syndromes and after stenting). In patients at low risk (stable cardiovascular disease), however, the bleeding risk of dual therapy exceeds its potential benefit. The dose and duration of pretreatment before stenting, the optimal duration of treatment after drug-eluting stent implantation, concurrent administration of platelet glycoprotein IIb/IIIa inhibitors, and the exact mechanism and clinical relevance of clopidogrel resistance are unclear.     

Risk of Bleeding on Triple Antithrombotic Therapy After Percutaneous Coronary Intervention/Stenting: A Systematic Review and Meta-analysis

Background

There are no reported randomized controlled trials of triple antithrombotic therapy (TT; aspirin plus a thienopyridine plus vitamin K antagonist) vs dual antiplatelet therapy (DAPT; aspirin plus a thienopyridine) among patients undergoing percutaneous coronary intervention with stenting (PCI-S). A systematic review and meta-analysis was undertaken to assess the risk of bleeding among patients receiving TT after PCI-S.

Methods

Electronic databases were searched for studies reporting bleeding among patients receiving TT after PCI-S. Of the 4108 articles screened, 18 met study inclusion criteria and underwent detailed data extraction: of these, 6 reported in-hospital outcomes, 14 reported 30-day outcomes, and 9 reported 6-month outcomes. At each time point, pooled estimates of bleeding with TT were ascertained and where possible summary odds ratios (ORs) for comparative risks vs DAPT were calculated.

Results

The pooled estimate of major bleeding rate with TT post PCI-S was 2.38% by 30 days postprocedure (95% confidence interval [CI], 0.98-3.77%) and 4.55% by 6 months postdischarge (95% CI, 0.56-8.53%). At 30 days and 6 months the rates of major bleeding with TT were significantly higher than those observed with DAPT: OR, 2.38 at 30 days (95% CI, 1.05-5.38) and OR, 2.87 at 6 months (95% CI, 1.47-5.62).

Conclusions

This systematic review and meta-analysis of reports of triple therapy with a vitamin K antagonist, aspirin, and clopidogrel after PCI-S provides precise and valid bleeding risk data. Based on existing observational studies the rates of major and any bleeding associated with TT are clinically important and significantly greater than those reported with DAPT.     

Low-dose aspirin for primary prevention of cardiovascular disease

Progressive atherosclerosis followed by plaque rupture is the leading cause of acute cardiovascular events. Inhibition of platelet aggregation by acetylsalicylic acid (aspirin) reduces recurrent cardiovascular events in secondary prevention trials. By extracting data from available randomized trials that examined aspirin prevention in persons without previously known cardiovascular disease, we evaluated the use of aspirin as a primary prevention measure. Using the raw data presented in the source publication on death, fatal and nonfatal myocardial infarctions, and cerebrovascular accidents, all relative and absolute risk reductions were recalculated with confidence intervals. In healthy men above 45 years of age, men with an increased cardiovascular risk profile, and persons with diabetes mellitus or hypertension, the use of aspirin reduces the incidence of myocardial infarction and has a neutral effect on cerebrovascular events. The protective effect of aspirin is apparently most prominent in those persons with an increased risk of manifest atherosclerotic vascular disease. Notwithstanding these results, for each patient it remains essential to balance the cardiovascular risk profile against the small increased risk of bleeding complications when prescribing aspirin.     

Impact of aspirin with or without clopidogrel on postoperative bleeding and blood transfusion in coronary surgical patients treated prophylactically with a low-dose of aprotinin.

AIMS: Aspirin combined with clopidogrel is the treatment of choice for acute coronary syndromes. Although the maintenance of aspirin until surgery does not affect postoperative bleeding after coronary artery bypass graft (CABG) surgery, the latter may be dramatically increased when clopidogrel is continued over a period of 5 days preoperatively. METHODS AND RESULTS: This prospective observational study included 217 consecutive patients scheduled for first-time CABG. Postoperative bleeding and blood transfusion requirements were compared (equivalence) between patients pretreated during a period of 5 days prior surgery by either aspirin alone (n = 157) or combined with clopidogrel (n = 60). Aprotinin was systematically used in all these patients considered as high risk for bleeding. We found no significant difference between both groups concerning the preoperative characteristics except for unstable angina (33 vs. 19%, P = 0.02) and left main coronary artery stenosis (27 vs. 13%, P = 0.02), which were more frequent in patients receiving clopidogrel. The median chest tube output was similar in both groups 24 h postoperatively at 350 mL (95% CI 150-850) vs. 375 mL (95% CI 175-875), and the difference between groups (7%, 95% CI -9 to 22) did not encompass the predetermined margins of equivalence (25%). No significant difference was found on blood transfusion use (38 vs. 38%, P = 0.99). After adjustment by a propensity score, we found that clopidogrel was not associated with an increased risk of excessive bleeding. CONCLUSION: In patients undergoing first-time CABG and treated prophylactically with aprotinin, aspirin and clopidogrel may be continued until surgery without increasing postoperative bleeding or transfusion requirements.     

Clinical outcomes associated with per‐operative discontinuation of aspirin in patients with coronary artery disease: A systematic review and meta‐analysis

Background: Postoperative state is characterized by increased thrombotic risk by virtue of platelet activation. Whether aspirin ameliorates this risk in patients with established coronary artery disease undergoing cardiac or noncardiac surgery is unknown. We conducted a systematic review and meta‐analysis to compare the risk of major adverse cardiac events (MACE) and the risk of bleeding in patients with early (3–5 or more days before surgery) vs. late discontinuation(<3–5 days)/no discontinuation of aspirin. Methods: Multiple databases were searched from inception of these databases until March 2015 to identify studies that reported discontinuation of aspirin in patients undergoing surgery. The outcomes measured were all cause mortality, nonfatal myocardial infarction and other relevant thrombotic events (MACE) which also may include, fatal and nonfatal MI, stent thrombosis and restenosis, stroke, perioperative cardiovascular complications (heart failure, MI, VTE, acute stroke) and perioperative bleeding during the perioperative period to up to 30 days after surgery. Results: A total of 1,018 titles were screened, after which six observational studies met the inclusion criteria. Our analysis suggests that there is no difference in MACE with planned discontinuation of aspirin (OR = 1.17, 95% CI = 0.76–1.81; P = 0.05; I² = 55%). Early discontinuation of aspirin showed a decreased risk of peri‐operative bleeding (OR 0.82, 95% CI = 0.67–0.99; P = 0.04; I² = 42%). Conclusion: Our analysis suggests that planned short‐term discontinuation in the appropriate clinical setting appears to be safe in the correct clinical setting with no increased risk of thrombotic events and with a decreased risk of bleeding. © 2016 Wiley Periodicals, Inc.