Impact of prior use or recent withdrawal of oral antiplatelet agents on acute coronary syndromes

Risk of Hemorrhage Attributed to Underlying Chronic Diseases and Uninterrupted Aspirin Therapy of Patients Undergoing Minor Oral Surgical Procedures: A Retrospective Cohort Study

Objectives

This study aimed to estimate the risk of bleeding following minor oral surgical procedures and uninterrupted aspirin therapy in high-risk patients or patients with existing chronic diseases compared to patients who did not use aspirin during minor oral surgery at a public hospital.

Methods

This retrospective cohort study analyzed the data of 2912 patients, aged 20 years or older, who underwent 5251 minor oral surgical procedures at a district hospital in Thailand. The aspirin group was comprised of patients continuing aspirin therapy during oral surgery. The non-aspirin group (reference) included all those who did not use aspirin during surgery. Immediate and late-onset bleeding was evaluated in each procedure. The risk ratio of bleeding was estimated using a multilevel Poisson regression.

Results

The overall cumulative incidence of immediate bleeding was 1.3% of total procedures. No late-onset bleeding was found. A significantly greater incidence of bleeding was found in the aspirin group (5.8% of procedures, p<0.001). After adjusting for covariates, a multilevel Poisson regression model estimated that the bleeding risk in the aspirin group was 4.5 times higher than that of the non-aspirin group (95% confidence interval, 2.0 to 10.0; p<0.001). However, all bleeding events were controlled by simple hemostatic measures.

Conclusions

High-risk patients or patients with existing chronic diseases who continued aspirin therapy following minor oral surgery were at a higher risk of hemorrhage than general patients who had not used aspirin. Nonetheless, bleeding complications were not life-threatening and could be promptly managed by simple hemostatic measures. The procedures could therefore be provided with an awareness of increased bleeding risk, prepared hemostatic measures, and postoperative monitoring, without the need for discontinuing aspirin, which could lead to more serious complications.

Association Between Previous Use of Antiplatelet Therapy and Intracerebral Hemorrhage Outcomes

BACKGROUND AND PURPOSE

Although the use of antiplatelet therapy (APT) is associated with the risk of intracerebral hemorrhage (ICH), there are limited data on prestroke APT and outcomes, particularly among patients on combination APT (CAPT). We hypothesized that the previous use of antiplatelet agents is associated with increased mortality in ICH.

METHODS

We analyzed data of 82 576 patients with ICH who were not on oral anticoagulant therapy from 1574 Get with the Guidelines-Stroke hospitals between October 2012 and March 2016. Patients were categorized as not on APT, on single-APT (SAPT), and CAPT before hospital presentation with ICH. We described baseline characteristics, comorbidities, hospital characteristics and outcomes, overall and stratified by APT use.

RESULTS

Before the diagnosis of ICH, 65.8% patients were not on APT, 29.5% patients were on SAPT, and 4.8% patients were on CAPT. There was an overall modest increased in-hospital mortality in the APT group versus no APT group (24% versus 23%; adjusted odds ratio, 1.05; 95% confidence interval, 1.01-1.10). Although patients on SAPT and CAPT were older and had higher risk profiles in terms of comorbidities, there was no significant difference in the in-hospital mortality among patients on SAPT versus those not on any APT (23% versus 23%; adjusted odds ratio, 1.01; 95% confidence interval, 0.97-1.05). However, in-hospital mortality was higher among those on CAPT versus those not on APT (30% versus 23%; adjusted odds ratio, 1.50; 95% confidence interval, 1.39-1.63).

CONCLUSIONS

Our study suggests that among patients with ICH, previous use of CAPT, but not SAPT, was associated with higher risk for in-hospital mortality.

Additive antithrombotic effect of ASP6537, a selective cyclooxygenase (COX)-1 inhibitor, in combination with clopidogrel in guinea pigs

Clopidogrel (Plavix^®, Sanofi-Aventis), the adenosine diphosphate P2Y₁₂ receptor antagonist, is reported to be effective in the prevention of cardiovascular events and is often used in combination with aspirin, particularly in high-risk patients. ASP6537 is a reversible cyclooxygenase (COX)-1 inhibitor that is under investigation as an anti-platelet agent. First, we investigated the reversibility of the antiplatelet effect of ASP6537 and its interaction with ibuprofen to compare the usability of ASP6537 with that of aspirin. We then evaluated the antithrombotic effect of ASP6537 in combination with clopidogrel using a FeCl₃-induced thrombosis model in guinea pigs. ASP6537 exerted reversible antiplatelet activity, and no pharmacodynamic interaction with ibuprofen was noted. When administered as monotherapy, ASP6537 exerted a significant antithrombotic effect at ≥3mg/kg, while aspirin inhibited thrombosis at 100mg/kg. ASP6537 exerted significant additive effects in combination with clopidogrel, and the minimum antithrombotic dose was reduced by concomitant administration of clopidogrel. Our study showed that ASP6537 did not interact with ibuprofen and has clear additive effects in combination with clopidogrel. ASP6537 may therefore represent a promising antiplatelet agent for use in clinical settings in combination with clopidogrel.

Perioperative complications following preoperative cessation of antithrombotic agents for total knee arthroplasty: A retrospective study

The number of elderly patients undergoing total knee arthroplasty (TKA) has steadily increased. Elderly patients undergoing TKA usually have underlying diseases, and some of them take antithrombotic agents for the prevention or treatment of these co-morbidities, including cardiovascular, cerebrovascular, or thromboembolic diseases. When these patients are scheduled to undergo TKA, preoperative cessation of antithrombotic agents is considered on the basis of its risks and benefits. This study was aimed to evaluate the impact of discontinuing antithrombotic agents for primary total knee arthroplasty (TKA) on perioperative complications.Patients who underwent primary TKA between 2008 and 2012 were identified, and classified into two groups: group A, in whom antithrombotic agents were ceased preoperatively, and group B, in which patients did not receive antithrombotic therapy. Patient characteristics, history of antithrombotic therapy, intraoperative blood loss, perioperative blood transfusion, postoperative 30-day complications, and postoperative hospital stay were recorded.Of 885 patients undergoing primary TKA, 218 (24.6%) patients were included in group A, and 667 (75.4%) in group B. Group A received transfusion more frequently than group B (P < 0.001). However, there was no difference between the two groups in terms of intraoperative blood loss, postoperative 30-day complications, and postoperative hospital stay.Patients who discontinued antithrombotic drugs before primary TKA do not have a higher incidence of postoperative 30-day complications, including cardiovascular, cerebrovascular, or thromboembolic events. Moreover, the estimated intraoperative blood loss was not different compared with patients not receiving antithrombotic agents preoperatively. Larger prospective studies of this issue are required.

Dual anti-platelet therapy and dento-alveolar surgery. How do we manage patients on anti-platelet medication?

OBJECTIVE

The optimum management of dual anti-platelet therapy (DAPT) in patients undergoing dentoalveolar surgery is controversial. The lack of guidelines has meant clinicians have been left to manage these cases from specialist advice or past experience. In view of this the British Association of Oral Surgeons (BAOS) membership was surveyed to assess current practice.

DESIGN

An electronic survey consisting of nine closed multiple-choice questions was circulated to all 435 registered BAOS members. A section for open comments was also included. The data was transcribed, organised and reduced to themes by hand and finally analysed.

RESULTS

One hundred and eighty members completed the questionnaire giving a response rate of 41%. Ninety-two percent of clinicians had direct involvement in managing patients on DAPT and of these 80% had not encountered a bleeding complication. DAPT was continued for simple dental extraction under local anaesthetic by 83% of respondents and 73% for surgical extractions. Two thirds of the respondents did not follow any guidelines but for those that did the most common was the UK Medicines Information protocols. Only 10% of respondents reported a significant post-operative bleeding complication following surgery in patients on DAPT.

CONCLUSION

This survey confirmed the continued variable management of patients on DAPT undergoing dentoalveolar surgery. Reported bleeding rates were low with over 75% of patients not having their DAPT treatment interrupted.

Influence of aspirin or heparin on platelet function and postoperative blood loss after coronary artery bypass surgery

The aim of the study was to assess the effect of aspirin or heparin pretreatment on platelet function and bleeding in the early postoperative period after coronary artery bypass grafting (CABG) surgery.

Seventy-five male patients with coronary artery disease who underwent CABG with cardiopulmonary bypass (CPB) were studied. The patients were divided into three groups: Group 1 ( n = 25) included patients receiving aspirin pretreatment, Group 2 ( n = 22) received heparin pretreatment, and Group 3 ( n = 28) included patients who received no antiplatelet or anticoagulant pretreatment. Twenty-four hours after surgery, all patients were administered aspirin therapy that was continued throughout their hospitalization period. We assessed the following preoperative blood coagulation indices: activated partial thromboplastin time (aPTT), international normalized ratio (INR), and fibrinogen. We compared platelet count and platelet aggregation induced by adenosinediphosphate (ADP) before surgery, 1 h after surgery, 20 h after surgery and on the seventh postoperative day. We assessed drained blood loss within 20 postoperative hours.

Preoperative blood coagulation indices did not differ among the groups. Platelet count was also similar. One hour after surgery, platelet count significantly decreased in all groups ( p <0.001), after 20 postoperative hours it did not undergo any marked changes, and on the seventh postoperative day, it significantly increased in all groups ( p <0.001). Before surgery, the lowest index of ADP-induced platelet aggregation was found in Group 1 ( p <0.05). One hour after surgery, platelet aggregation significantly decreased in all groups, most markedly in Group 3 ( p <0.001), yet after 20 h, its restitution tendency and a significant increase in all groups was noted. On the seventh day, a further increase in the statistical mean platelet aggregation value was noted in Groups 2 and 3. Comparison of platelet aggregation after 20 postoperative hours and on the seventh day after surgery revealed a significantly higher than 10% increase of the index in 32% of patients in Group 1 ( p <0.05), 27.3% of patients in Group 2 ( p <0.05) and in 35.7% of patients in Group 3 ( p <0.001). The lowest statistically significant value of postoperative blood loss was noted in Group 2 ( p <0.01).

Our study has shown that aspirin or heparin pretreatment had no impact on the dynamics of platelet function in the early postoperative period after CABG. The lowest postoperative blood loss was noted in patients pretreated with heparin.

Dental extraction without stopping single or dual antiplatelet therapy: results of a retrospective cohort study

The aim of this study was to investigate the incidence of bleeding after dental extraction without stopping antiplatelet therapy. Postoperative bleeding was assessed in a total of 1271 patients who were divided into two groups: a study group comprising 183 patients on antiplatelet therapy (aspirin 125 patients/185 occasions; clopidogrel 42 patients/65 occasions; dual therapy 16 patients/24 occasions) who underwent 548 dental extractions on 274 occasions, and a control group comprising 1088 patients who were not receiving any antiplatelet or anticoagulant therapy and underwent 2487 dental extractions on 1472 occasions. The incidence of postoperative bleeding was higher in the study group (5/274, 1.8%) than in the control group (10/1472, 0.7%), and also in the dual antiplatelet subgroup (1/24, 4.2%) than in the single antiplatelet subgroups (clopidogrel: 2/65, 3.1%; aspirin: 2/185, 1.1%); however, these differences were not significant. Postoperative bleeding was managed successfully by repacking with Gelfoam impregnated with tranexamic acid powder in 12 patients and by resuturing in three of the control patients undergoing extraction of impacted teeth with flap elevation. These findings indicate that there is no need to interrupt antiplatelet drugs before dental extraction.

Stopping vs. Continuing Aspirin before Coronary Artery Surgery

BACKGROUND

Most patients with coronary artery disease receive aspirin for primary or secondary prevention of myocardial infarction, stroke, and death. Aspirin poses a risk of bleeding in patients undergoing surgery, but it is unclear whether aspirin should be stopped before coronary artery surgery.

METHODS

We used a 2-by-2 factorial trial design to randomly assign patients who were scheduled to undergo coronary artery surgery and were at risk for perioperative complications to receive aspirin or placebo and tranexamic acid or placebo. The results of the aspirin trial are reported here. Patients were randomly assigned to receive 100 mg of aspirin or matched placebo preoperatively. The primary outcome was a composite of death and thrombotic complications (nonfatal myocardial infarction, stroke, pulmonary embolism, renal failure, or bowel infarction) within 30 days after surgery.

RESULTS

Among 5784 eligible patients, 2100 were enrolled; 1047 were randomly assigned to receive aspirin and 1053 to receive placebo. A primary outcome event occurred in 202 patients in the aspirin group (19.3%) and in 215 patients in the placebo group (20.4%) (relative risk, 0.94; 95% confidence interval, 0.80 to 1.12; P=0.55). Major hemorrhage leading to reoperation occurred in 1.8% of patients in the aspirin group and in 2.1% of patients in the placebo group (P=0.75), and cardiac tamponade occurred at rates of 1.1% and 0.4%, respectively (P=0.08).

CONCLUSIONS

Among patients undergoing coronary artery surgery, the administration of preoperative aspirin resulted in neither a lower risk of death or thrombotic complications nor a higher risk of bleeding than that with placebo. (Funded by the Australian National Health and Medical Research Council and others; Australia New Zealand Clinical Trials Registry number, ACTRN12605000557639.).

Effect of Preoperative Aspirin Replacement With Enoxaparin in Patients Undergoing Primary Isolated On-Pump Coronary Artery Bypass Grafting

Management of preoperative antiplatelet therapy in coronary artery bypass grafting (CABG) is variable among surgeons: guidelines collide with prejudices because replacement of aspirin with low-molecular-weight heparin is still performed because of a presumed minor bleeding risk. This study aims to analyze postoperative bleedings and complications in patients scheduled for elective primary isolated on-pump CABG, depending on preoperative aspirin treatment or its replacement with enoxaparin. In this cohort study, we propensity score matched 200 patients in whom aspirin was stopped at least 5 days before CABG and replaced with enoxaparin and 200 patients who continued aspirin therapy until the day before surgery. Postoperative bleedings and complications were monitored during hospitalization. Among patients who continued aspirin treatment, mean overall bleeding was 701.0 ± 334.6 ml, whereas in the matched enoxaparin group, it was significantly greater (882.6 ± 64.6 ml, p value <0.001); this was associated with reduced postoperative complications, lower values of postoperative C-reactive protein in aspirin takers, and a presumed protective effect for statins. After propensity score adjustment, aspirin treatment carried a protective effect against major postoperative bleeding (odds ratio 0.312, p = 0.001). In conclusion, postoperative bleeding is reduced in patients who continued aspirin, likely due to a reduction in postoperative inflammation. The practice of empirically discontinuing aspirin and replacing it with enoxaparin before CABG should be abandoned. Patients with coronary artery disease referred to CABG should continue antiplatelet medications until the surgical procedure. Those results might be extended to patients under oral anticoagulant therapy requiring CABG.

Safety of prasugrel in real-world patients with ST-segment elevation myocardial infarction: 1-year results from a prospective observational study (Bleeding and Myocardial Infarction Study)

BACKGROUND

Antiplatelet therapies, including prasugrel, are a cornerstone in the treatment of ST-segment elevation myocardial infarction (STEMI), but are associated with a bleeding risk. This risk has been evaluated in randomized trials, but few data on real-world patients are available.

AIM

To evaluate prasugrel safety in real-world patients with STEMI.

METHODS

Consecutive patients with STEMI were recruited over 1 year. Follow-up was done at 3 months and 1 year to evaluate prasugrel safety from hospital discharge to the STEMI anniversary date. The primary outcome was occurrence of any major bleeding according to the Bleeding Academic Research Consortium (BARC) 3 or 5 definitions, or minor bleeding according to the BARC 2 definition.

RESULTS

Overall, 1083 patients were recruited. Compared to patients treated with aspirin+clopidogrel, patients treated with aspirin+prasugrel had fewer BARC 3 or 5 bleedings (two [0.4%] patients vs. nine [1.8%] patients; P=0.04), but more BARC 2 bleedings (45 [9.3%] patients vs. 20 [4.0%] patients; P<0.001). The baseline characteristics of prasugrel- and clopidogrel-treated patients differed because the former were carefully selected (younger, higher body mass index, less frequent history of stroke). In the overall population, rates of in-hospital and out-of-hospital major bleeding were 2.6% (n=28) and 1.3% (n=13), respectively.

CONCLUSION

The rate of major bleeding, particularly out-of-hospital bleeding, in patients treated with prasugrel is low within 1 year after a STEMI. Accurate selection of patient candidates for prasugrel is likely to have reduced the risk of bleeding.

The role of point-of-care assessment of platelet function in predicting postoperative bleeding and transfusion requirements after coronary artery bypass grafting

OBJECTIVE

OBJECTIVE platelet function assessment after cardiac surgery can predict postoperative blood loss, guide transfusion requirements and discriminate the need for surgical re-exploration. We conducted this study to assess the predictive value of point-of-care testing platelet function using the Multiplate® device.

METHODS

Patients undergoing isolated coronary artery bypass grafting were prospectively recruited ( n = 84). Group A ( n = 42) patients were on anti-platelet therapy until surgery; patients in Group B ( n = 42) stopped anti-platelet treatment at least 5 days preoperatively. Multiplate® and thromboelastography (TEG) tests were performed in the perioperative period. Primary end-point was excessive bleeding (>2.5 ml/kg/h) within first 3 h postoperative. Secondary end-points included transfusion requirements, re-exploration rates, intensive care unit and in-hospital stays.

RESULTS

Patients in Group A had excessive bleeding (59% vs. 33%, P = 0.02), higher re-exploration rates (14% vs. 0%, P < 0.01) and higher rate of blood (41% vs. 14%, P < 0.01) and platelet (14% vs. 2%, P = 0.05) transfusions. On multivariate analysis, preoperative platelet function testing was the most significant predictor of excessive bleeding (odds ratio [OR]: 2.3, P = 0.08), need for blood (OR: 5.5, P < 0.01) and platelet transfusion (OR: 15.1, P < 0.01). Postoperative "ASPI test" best predicted the need for transfusion (sensitivity - 0.86) and excessive blood loss (sensitivity - 0.81). TEG results did not correlate well with any of these outcome measures.

CONCLUSIONS

Peri-operative platelet functional assessment with Multiplate® was the strongest predictor for bleeding and transfusion requirements in patients on anti-platelet therapy until the time of surgery.

Continuing aspirin therapy during percutaneous nephrolithotomy: unsafe or under-utilized?

INTRODUCTION

Aspirin, as an inhibitor of platelets, is traditionally discontinued prior to percutaneous nephrolithotomy (PCNL) given the concern for increased surgical hemorrhage. However, this practice is based on expert opinion only, and mounting evidence suggests holding aspirin perioperatively can be more harmful than once thought. We sought to compared PCNL outcomes and complications in patients continuing aspirin to those stopping aspirin perioperatively.

METHODS

A retrospective review was performed of 321 consecutive PCNLs done between July 2012 and March 2014. Patients were separated into two groups. The on-aspirin group consisted of patients continuing aspirin throughout the perioperative period. The off-aspirin group had aspirin held temporarily pre- and postoperatively. Surgical outcomes and complications were compared between groups.

RESULTS

Of the 321 PCNLs, 60 (18.7%) occurred in patients chronically taking aspirin. The on-aspirin group included 17 PCNLs (5.2%), while the off-aspirin group included 43 PCNLs (13.4%). There were no differences between groups in terms of operative time (77 minutes vs 74 minutes, p=0.212), hemoglobin change (p=0.522), stone size (21 mm vs 22 mm, p=1.0), stone-free rate (p=0.314), median length of hospitalization (p=0.642), transfusion rate (p=0.703), or total complications (p=1.0). No patient experienced a thromboembolic event.

CONCLUSIONS

PCNL is safe in patients continuing aspirin perioperatively and does not result in more blood transfusions, angioembolization procedures, or complications. Patients with large stone burdens who are at high risk for thromboembolic events appear to be able to safely undergo PCNL without discontinuing aspirin.

Does aspirin administration increase perioperative morbidity in patients with cardiac stents undergoing spinal surgery?

STUDY DESIGN

Cohort.

OBJECTIVE

To compare the perioperative morbidity of patients with cardiac stents after spine surgery who continue to take aspirin before and after the operation with a similar group of patients who preoperatively discontinued aspirin.

SUMMARY OF BACKGROUND DATA

The preoperative discontinuation of anticoagulant therapy has been the standard of care for orthopedic surgical procedures. However, recent literature has demonstrated significant cardiac risk associated with aspirin withdrawal in patients with cardiac stents. Although it has recently been demonstrated that performing orthopedic surgery while continuing low-dose aspirin therapy seems to be safe, studies focused on spinal surgery have not yet been performed. Because of the risk of intraspinal bleeding and the serious consequences of subsequent epidural hematoma with associated spinal cord compression, spinal surgeons have been reluctant to operate on patients taking aspirin.

METHODS

This institutional review board-approved study included 200 patients. Preoperative parameters and postoperative outcome measures were analyzed for 100 patients who underwent spinal surgery after the discontinuation of anticoagulation therapy and 100 patients who continued to take daily aspirin through the perioperative period. The primary outcome measure was serious bleeding-related postoperative complications such as spinal epidural hematoma. The operative time, intraoperative estimated blood loss, hospital length of stay, transfusion of blood products, and 30-day hospital readmission rates were also recorded and compared.

RESULTS

The patients who continued taking aspirin in the perioperative period had a shorter hospital length of stay on average (4.1 ± 2.7 vs. 6.2 ± 5.8; P < 0.005), as well as a reduced operative time (210 ± 136 vs. 266 ± 143; P < 0.01), whereas there was no significant difference in the estimated blood loss (642 ± 905 vs. 697 ± 1187), the amount of blood products transfused, overall intra- and postoperative complication rate (8% vs. 11%), or 30-day hospital readmission rate (5% vs. 5%). No clinically significant spinal epidural hematomas were observed in either of the study groups.

CONCLUSION

The current study has observed no appreciable increase in bleeding-related complication rates in patients with cardiac stents undergoing spine surgery while continuing to take aspirin compared with patients who discontinued aspirin prior to surgery. Although very large studies will be needed to determine whether aspirin administration results in a small complication rate increase, the current study provides evidence that perioperative aspirin therapy is relatively safe in patients undergoing spinal surgery.

LEVEL OF EVIDENCE

2.

Patterns of Antiplatelet Therapy in Patients Who Have Experienced an Acute Coronary Event: A Descriptive Study in UK Primary Care

BACKGROUND

Antiplatelet (AP) therapy is well established for the secondary prevention of acute coronary events. However, patients may discontinue treatment, often owing to gastrointestinal (GI) complications, leaving them at elevated risk of recurrent cardiovascular events.

OBJECTIVES

This descriptive retrospective study assessed trends in prescription of AP agents and coprescription of gastroprotective therapy, after an acute coronary event. Discontinuation of AP therapy within 2 years of an event and factors predicting discontinuation were investigated.

METHODS

The study was conducted in a UK primary care setting from 2000 to 2008; a total of 27, 351 patients aged 50 to 84 years were included in the analysis. Main outcome measures were exposures to low-dose acetylsalicylic acid (ASA), clopidogrel, and proton pump inhibitors (PPIs).

RESULTS

At 90 days after an acute coronary event, 85.9% of patients had been prescribed some form of AP therapy and 33.6% of patients who were issued at least 1 ASA prescription in this period were also issued a PPI prescription. The use of dual antiplatelet therapy (DAT) 90 days after an event increased from 2% in 2000 to over 50% in 2008. An estimated 15.1% of patients on ASA monotherapy and 37.5% on DAT discontinued treatment within 1 year. A bleeding event during follow-up, including upper GI bleeding or hemorrhagic stroke, was the strongest predictor of discontinuation.

CONCLUSION

Although most patients were prescribed AP therapy in the 90 days following an acute coronary event, a substantial proportion discontinued DAT or ASA monotherapy within 1 year. It is essential that physicians consider strategies to reduce the risk of discontinuation of AP therapy.

Renal biopsy practice: What is the gold standard?

Renal biopsy (RB) is useful for diagnosis and therapy guidance of renal diseases but incurs a risk of bleeding complications of variable severity, from transitory haematuria or asymptomatic hematoma to life-threatening hemorrhage. Several risk factors for complications after RB have been identified, including high blood pressure, age, decreased renal function, obesity, anemia, low platelet count and hemostasis disorders. These should be carefully assessed and, whenever possible, corrected before the procedure. The incidence of serious complications has become low with the use of automated biopsy devices and ultrasound guidance, which is currently the “gold standard” procedure for percutaneous RB. An outpatient biopsy may be considered in a carefully selected population with no risk factor for bleeding. However, controversies persist on the duration of observation after biopsy, especially for native kidney biopsy. Transjugular RB and laparoscopic RB represent reliable alternatives to conventional percutaneous biopsy in patients at high risk of bleeding, although some factors limit their use. This aim of this review is to summarize the issues of complications after RB, assessment of hemorrhagic risk factors, optimal biopsy procedure and strategies aimed to minimize the risk of bleeding.

Postprocedural anticoagulation for specific therapeutic indications after revascularization for ST-segment elevation myocardial infarction (from the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction Trial)

Postprocedural anticoagulation (AC) after primary percutaneous coronary intervention (PCI) in ST-segment elevation myocardial infarction (STEMI) may be administered for a number of specific therapeutic indications (e.g. atrial fibrillation or left ventricular thrombus). However, the safety and effectiveness of such post-PCI AC for specific indications are not well defined. Thus, we sought to study outcomes after postprocedural AC for specific indications in patients undergoing primary PCI for STEMI in the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction trial. Patients who underwent primary PCI for STEMI in the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction trial were grouped according to whether they received specific indication AC. Adverse outcomes were assessed using propensity-adjusted multivariate analyses. After excluding patients who received post-PCI AC solely for routine prophylaxis, 410 patients (16.6%) received postprocedural AC for specific indications and 2,063 patients (83.4%) received no post-PCI AC. After propensity adjustment, use of postprocedural AC for specific indications was associated with higher rates of cardiac mortality, reinfarction, stent thrombosis, and major bleeding at 30 days compared with patients who received no AC post-PCI. In conclusion, in this large prospective study, use of postprocedural AC for specific indications after primary PCI for STEMI was independently associated with early rates of adverse ischemic and hemorrhagic outcomes. Post-PCI AC for specific indications was also associated with worse outcomes from 30 days to 3 years. Further studies are warranted to determine the optimal use of postprocedural AC after primary PCI in STEMI.

Percutaneous nephrolithotomy during uninterrupted aspirin therapy in high-cardiovascular risk patients: preliminary report

OBJECTIVE

To determine the feasibility and safety of performing percutaneous nephrolithotomy (PCNL) in high-cardiovascular risk patients remaining on aspirin therapy.

METHODS

We retrospectively reviewed all PCNLs performed by 3 fellowship-trained endourologists at a single institution between July 2012 and January 2014. All patients remaining on aspirin for imperative indications through the day of surgery were evaluated for surgical outcomes and thromboembolic events.

RESULTS

Of 281 PCNL procedures performed during the study period, 16 (5.7%) were performed in 14 patients taking aspirin, uninterrupted, through surgery. Mean surgery time was 66 minutes, mean estimated blood loss was 161 mL, and mean length of hospital stay was 2.8 days. All patients were stone free. There were no intraoperative complications. A total of 5 patients experienced a postoperative complication (n = 4, Clavien grade II; n = 1, Clavien grade IIIa). No patient experienced a perioperative thromboembolic or cardiac event. Three patients required a blood transfusion postoperatively, and none experienced delayed renal bleeding.

CONCLUSION

PCNL can be performed safely and effectively in high-cardiovascular risk patients continuing aspirin perioperatively. Compared with the potential sequelae of a thromboembolic or cardiac event, PCNL is associated with an acceptably low transfusion rate, and should be considered a viable treatment option for large renal stones in this population.

Aspirin, clopidogrel, and the surgeon

The rising use of antiplatelet therapy for primary prevention and secondary prevention of cardiovascular and cerebrovascular events poses a dilemma for physicians in the perioperative period. The proven benefits of aspirin in preventing further thrombotic events in patients with prior ACS or stroke make it difficult to withdraw this therapy. The risk of hypercoagulability associated with surgery is also independent of antiplatelet withdrawal, but adds to the rebound effect of platelet responsiveness. Therefore, aspirin should be continued whenever feasible. Similarly, the use of thienopyridines such as clopidogrel, especially for the prevention of stent thrombosis, should be maintained for at least the recommended time frame, if not longer. It is recognized that maintaining antiplatelet therapy is also not without risk, as bleeding complications have been well documented. Unfortunately, current perioperative guidelines do not often provide a simple solution for management. Therefore, the risk of bleeding has to be weighed against the risk of thrombosis, and decisions should be made with all providers caring for the patient on an individual basis.

Use of drug-eluting balloon coronary intervention prior to living donor kidney transplantation

Background

Kidney transplantation is the gold standard of therapy in patients with terminal renal insufficiency. Living donor transplantation is a well-established option in this field. Enlarging the donor’s pool implicates the acceptance of an increased rate of comorbidities. Among them, coronary artery disease is a growing problem. An increasing number of patients, undergoing living donation, receive antiplatelet therapies due to coronary disease.

Case presentation

Here we report about the perioperative treatment with a drug-eluting balloon in a patient with major cardiac risk factors who underwent kidney transplantation.

Conclusion

At the current time no recommendation can be given for the routine use of drug-eluting balloons.

Late and very late drug-eluting stent thrombosis in the immediate postoperative period after antiplatelet withdrawal: a retrospective study

Background:

Late (31–360 days after deployment) and very late (>360 days after deployment) stent thrombosis is a feared complication after drug-eluting stent (DES) deployment. The American College of Cardiology/American Heart Association guidelines recommend dual antiplatelet therapy for 12 months due to the lack of protection beyond this period in randomized trials. The perioperative period is a unique state of generalized hypercoagulability which can predispose people to DES thrombosis when combined with the rebound hypercoagulable effect of antiplatelet withdrawal.

Methods:

A retrospective chart review was performed to detect incidences of late and very late postoperative DES thrombosis after elective noncardiac surgery. Only definite and probable cases of stent thrombosis were included. All cases were analyzed for patient demographics, comorbidities, type of surgery, intervention history, preoperative antiplatelets management, postoperative course and outcome.

Results:

A total of six patients with prior DES deployment (10–42 months earlier, average 30 months) developed DES thrombosis (five very late and one late) in the immediate postoperative period. All patients had stable coronary artery disease and were cleared for surgery (intermediate cardiac risk surgery) by their cardiologist. In all patients, antiplatelets were discontinued 4–7 days (average 5.6 days) prior to surgery to minimize operative bleeding. Five of six patients developed ST-segment elevation myocardial infarction. Half of the patients had simultaneous two-vessel DES thrombosis and two cases had single vessel thrombosis. Three patients developed ventricular fibrillation and cardiac arrest. One-third of the patients died during the index hospitalization. Coronary thrombectomy and angioplasty was successful in the remaining four cases. The incidence of postoperative late and very late DES thrombosis among all patients undergoing noncardiac surgery who were older than 40 years was 0.006%.

Conclusion:

Caution should be exercised when attempting to withdraw antiplatelets preoperatively in patients with DES even when the recommended 12-month period of dual antiplatelet therapy (DAPT) has elapsed. The significant morbidity and mortality of this complication warrants further research to study the ideal perioperative management of antiplatelets in patients with prior DES deployment over 1 year who are still receiving DAPT.

[ASA and clopidogrel for urological operations. Perioperative management]

In a systematic overview and meta-analysis among more than 50,000 patients at risk for coronary artery disease, not adhering to or discontinuing aspirin (acetylsalicylic acid, ASA) was associated with a significantly increased risk of non-fatal myocardial infarction or death. Withdrawal of low dose aspirin was correlated with a threefold increase in the risk of adverse cardiovascular events. This risk is present irrespective of the length of time patients had been taking low dose aspirin. Therefore, in patients on chronic low dose aspirin for secondary prevention of cardiovascular disease, aspirin should never be discontinued. In the few available studies in urological surgery the increase in bleeding does not translate into a significant increase in specific morbidity. This seems to be also true for the additional administration of clopidogrel to aspirin. Nevertheless, in patients with drug-eluting stents and dual antiplatelet therapy, urologists should ensure a multidisciplinary management of the perioperative course.

Complications of hip fracture surgery on patients receiving clopidogrel therapy

INTRODUCTION

Clopidogrel (Plavix(®)) may influence patient safety during fracture surgery. Our study examines the incidence of complications for patients undergoing hemiarthroplasty on clopidogrel therapy.

MATERIALS AND METHODS

All patients, who underwent hemiarthroplasty between 2005 and 2011 were retrospectively reviewed. Patients were placed in two comparative groups based on the use of clopidogrel antiplatelet therapy. Records were reviewed for patient demographics, ASA score, pre and postoperative hemoglobin, time to surgery, length of stay, bleeding events, transfusions and complications. Comparative statistical analysis was performed using Fisher's exact test and Student's t test, using P < 0.05 to identify statistical significance.

RESULTS

A total of 203 charts were reviewed, of which 162 patients met inclusion/exclusion criteria. One hundred and twelve females and 50 males with mean age of 84 years were identified. The clopidogrel group consisted of 15 (9.3 %) patients and the nonclopidogrel group 147 (90.7 %). The clopidogrel group had more comorbidities resulting in a significantly higher ASA score (3.9 vs. 2.9), and lower preoperative hemoglobin (11.3 vs. 12.0). There was no significant difference identified in time to surgery, intraoperative blood loss, hemoglobin on days 1-3, or number of transfusions received between groups. Patients on clopidogrel were seen to have significantly longer hospital stays (10.6 vs. 7.4 days). However, a similar rate of wound and bleeding related complications (6.7 vs. 6.1 %) was seen.

CONCLUSIONS

The optimal treatment for hip fracture patients on antiplatelet therapy is unclear. However, in this study there appears to be no significant difference with regards to bleeding and bleeding related wound complications, suggesting it is safe to proceed with hemiarthroplasty for patients receiving clopidogrel.

Bleeding complications in patients with coronary stents during non-cardiac surgery

INTRODUCTION

Patients with coronary stents often undergo non-cardiac invasive procedures. These are often associated with thrombotic and/or hemorrhagic complications. The type of procedure, perioperative antiplatelet therapy, and other patient-related factors influence the risk of postoperative haemorrhage. Our objective was to analyze the postoperative risk factors for hemorrhagic complications and to determine the impact of antiplatelet and anticoagulant therapy strategies on postoperative bleeding risk in patients with coronary stents undergoing non-cardiac surgery.

PATIENTS AND METHODS

Prospective, multicentre observational cohort study of 1134 consecutive patients with coronary stents undergoing non-cardiac surgery between April 2007 and April 2009. The primary outcome measure was the occurrence of an hemorrhagic complication during the first 30days following the surgery or intervention.

RESULTS

Among the 1134 patients evaluated, 108 (9.5%) experienced a postoperative hemorrhagic complication (with a median time to occurrence of 5.3days). These complications were considered major, involved the operative site, and required reoperation in 92 (85.2%), 92 (85.2%), and 20 (18.5%) of patients, respectively. Mortality in patients with a haemorrhagic complication was 12% (n=13). Independent postoperative factors associated with haemorrhagic complications were identified as a high and intermediate bleeding risk procedure and the use and dose of anticoagulants. When interrupted before the procedure, resumption of antiplatelet treatment was delayed in patients developing early postoperative hemorrhagic complications.

CONCLUSION

Patients with coronary stents who undergo surgery are at high risk for hemorrhagic complications.

Optimizing the use of aspirin for cardiovascular prevention

This article describes the mechanism of action, pharmacokinetics, and pharmacodynamics of aspirin at doses used for cardiovascular prevention and provides specific management recommendations for optimal use in clinical practice. The paper highlights practical aspects related to antiplatelet therapy, including the optimal dose of aspirin, concomitant treatment with other NSAIDs, and strategies for the prevention of gastrointestinal toxicity. Specifically, we revise the benefits and hazards in different clinical settings to help the clinician in the decision-making process for individuals who have different risks for cardiovascular and gastrointestinal bleeding events.

Safety and efficacy of cangrelor, an intravenous, short-acting platelet inhibitor in patients requiring coronary artery bypass surgery

OBJECTIVE

Oral P2Y₁₂ platelet receptor inhibitors are a cornerstone of reducing complications in patients with acute coronary syndromes or coronary stents. Guidelines advocate discontinuing treatment with P2Y₁₂ platelet receptor inhibitors before surgery. Cangrelor, a short-acting, reversible, intravenously administered P2Y₁₂ platelet inhibitor is effective in achieving appropriate platelet inhibition in patients who are awaiting coronary artery bypass grafting (CABG) and require P2Y₁₂ inhibition. The objective of this study was to assess the effects of preoperative cangrelor on the incidence of perioperative complications, which are currently unknown.

METHODS

Patients (n = 210) requiring preoperative clinical administration of thienopyridine therapy were randomized in a multicenter, double-blinded study to receive cangrelor or placebo while awaiting CABG after discontinuation of the thienopyridine. Optimal platelet reactivity, which was defined as <240 P2Y₁₂ platelet reaction units, was measured with serial point-of-care testing (VerifyNow). Pre- and postoperative outcomes, bleeding values, and transfusion rates were compared. To quantify potential risk factors for bleeding, we developed a multivariate logistic model.

RESULTS

The differences between the groups in bleeding and perioperative transfusion rates were not significantly different. The rate of CABG-related bleeding was 11.8% (12/102) in cangrelor-treated patients and 10.4% (10/96) in the placebo group (P = .763). Transfusion rates for the groups were similar. Serious postoperative adverse events for the cangrelor and placebo groups were 7.8% (8/102) and 5.2% (5/96), respectively (P = .454).

CONCLUSIONS

Compared with placebo, bridging patients with cangrelor prior to CABG effectively maintains platelet inhibition without increasing post-CABG complications, including bleeding and the need for transfusions. These data suggest cangrelor treatment is a potential strategy for bridging patients requiring P2Y₁₂ receptor inhibition while they await surgery.

Post-operative simultaneous very late two-vessel drug eluting stent thrombosis with sparing of bare metal stent in a Jehovah's witness after clopidogrel withdrawal

Very late stent thrombosis is a feared complication after drug-eluting stent (DES) implantation. Several factors related to the patient, generation and type of the deployed stent, procedure, and premature antiplatelet withdrawal are known to contribute to this complication. Herein, we describe a case of a Jehovah's witness patient who developed simultaneous two-vessel 1st generation DES thrombosis 5.4 and 3.5 years after deployment [with sparing of the bare metal stent (BMS)] in the immediate post-operative period secondary to clopidogrel withdrawal. The case was complicated by ST-segment elevation myocardial infarction, cardiogenic shock, and a ventricular fibrillation cardiac arrest requiring urgent percutaneous coronary intervention. The acute thrombosis of DESs with sparing of the BMS exemplify how they are more prone to this complication due to delayed endothelialization of stent struts and neoinitimal coverage. <Learning objective: Extreme caution should be excercised when attempting to withdraw antiplatelets immediately before surgery in patients with drug eluting stents even if the recomended 12-month period of dual antiplatelet therapy has elapsed because of the risk of very late stent thrombosis.>.

Aspirin discontinuation syndromes: clinical implications of basic research studies

Abrupt discontinuation of many drugs used in medicine causes withdrawal syndromes, some of which can be fatal. Discontinuation of a number of cardiovascular drugs can increase the risk of cardiovascular events. Whereas aspirin administration is known to decrease the risk of vascular ischemic problems, aspirin withdrawal may temporarily increase the risk of thrombotic events. Indeed, aspirin withdrawal has been associated with an increased risk of thrombosis both in clinical and fundamental research studies. Such complications occur within the first month after interrupting aspirin therapy and their mechanism remains unexplained. We have previously demonstrated that aspirin, when injected as a single high dose (100 mg/kg), induces a prothrombotic state in the rat, similar to that described above, 8 and 10 days after administration. This effect in the rat may be reproduced 1 hour after a single injection of ultra-low-dose aspirin. Caution is therefore required regarding the possibility of drug discontinuation effects within the framework of drug safety evaluation.