Aspirin and mortality from coronary bypass surgery

Perioperative management and monitoring of antiplatelet agents: a focused review on aspirin and P2Y12 inhibitors

Platelets play pivotal roles in hemostasis as well as pathological arterial thrombosis. The combination of aspirin and a P2Y₁₂ inhibitor has become the mainstay therapy in the ageing population with cardiovascular conditions, particularly during and after percutaneous coronary intervention. A number of novel P2Y₁₂ inhibitors has become available in the recent years, and they markedly vary in pharmacokinetic and pharmacodynamic properties. Perioperative physicians today face a challenge of preventing hemorrhage due to platelet inhibitors, while minimizing thrombotic risks. There are several point-of-care platelet function tests available in the peri-procedural assessment of residual platelet aggregation. However, these platelet function tests are not standardized in terms of sample processing, agonist type and potency as well as methods of detecting platelet activity. Understanding the differences in pharmacological properties of antiplatelet agents, principles of platelet function tests, and pertinent hemostatic strategies may be useful to anesthesiologists and intensivists who manage perioperative issues associated with antiplatelet agents. The objectives of this review are: 1) to discuss clinical data on aspirin and P2Y₁₂ inhibitors relating to perioperative bleeding, 2) to outline different features of point-of-care platelet function tests, and 3) to discuss therapeutic options for the prevention and treatment of bleeding associated with antiplatelet agents.

Management and Prevention of Saphenous Vein Graft Failure: A Review

Coronary artery bypass grafting (CABG) remains a vital treatment for patients with multivessel coronary artery disease (CAD), especially diabetics. The long-term benefit of the internal thoracic artery graft is well established and remains the gold standard for revascularization of severe CAD. It is not always possible to achieve complete revascularization through arterial grafts, necessitating the use of saphenous vein grafts (SVG). Unfortunately, SVGs do not have the same longevity, and their failure is associated with significant adverse cardiac outcomes and mortality. This paper reviews the pathogenesis of SVG failure, highlighting the difference between early, intermediate, and late failure. It also addresses the different surgical techniques that affect the incidence of SVG failure, as well as the medical and percutaneous prevention and treatment options in contemporary practice.

Effects of preoperative aspirin on perioperative platelet activation and dysfunction in patients undergoing off-pump coronary artery bypass graft surgery: A prospective randomized study

The benefit of aspirin use after coronary artery bypass graft surgery has been well proven. However, the effect of preoperative aspirin use in patients undergoing off-pump coronary artery bypass graft surgery (OPCAB) has not been evaluated sufficiently. To evaluate platelet function changes during OPCAB due to preoperative aspirin use, we conducted a randomized controlled trial using flow cytometry and the Multiplate^® analyzer. Forty-eight patients scheduled for elective OPCAB were randomized to the aspirin continuation (100 mg/day until operative day) and discontinuation (4 days before the operative day) groups. Platelet function was measured using the platelet activation markers CD62P, CD63, and PAC-1 by flow cytometry, and platelet aggregation was measured using the Multiplate^® analyzer, after the induction of anesthesia (baseline), at the end of the operation, and 24 and 48 h postoperatively. Findings of conventional coagulation assays, thromboelastography by ROTEM^® assays, and postoperative bleeding—related clinical outcomes were compared between groups. No significant change in CD62P, CD63, or PAC-1 was observed at the end of the operation or 24 or 48 h postoperatively compared with baseline in either group. The area under the curve for arachidonic acid—stimulated platelet aggregation, measured by the Multiplate^® analyzer, was significantly smaller in the aspirin continuation group (P < 0.01). However, chest tube drainage and intraoperative and postoperative transfusion requirements did not differ between groups. Our study showed that preoperative use of aspirin for OPCAB did not affect perioperative platelet activation, but it impaired platelet aggregation, which did not affect postoperative bleeding, by arachidonic acid.

Dual Antiplatelet Therapy Versus Aspirin Monotherapy in Diabetics With Multivessel Disease Undergoing CABG: FREEDOM Insights

BACKGROUND

Clinical practice guidelines recommend post-operative dual antiplatelet therapy (DAPT) in patients who undergo coronary artery bypass grafting (CABG) following acute coronary syndromes (ACS).

OBJECTIVES

The authors have evaluated DAPT utilization rates and associated outcomes among post-CABG patients with diabetes.

METHODS

In a post hoc, nonrandomized analysis from the FREEDOM (Future REvascularization Evaluation in patients with Diabetes mellitus: Optimal management of Multivessel disease) trial, we compared patients receiving DAPT (aspirin plus thienopyridine) and aspirin monotherapy at 30 days post-operatively. The primary outcome was the risk adjusted 5-year FREEDOM composite of all-cause mortality, nonfatal myocardial infarction, or stroke. Safety outcomes included major bleeding, blood transfusion, and hospitalization for bleeding.

RESULTS

At 30 days post-CABG, 544 (68.4%) patients received DAPT and 251 (31.6%) patients received aspirin alone. The median (25th, 75th percentile) duration of clopidogrel therapy was 0.98 (0.23 to 1.91) years. There was no significant difference in the 5-year primary composite outcome between DAPT- and aspirin-treated patients (12.6% vs. 16.0%; adjusted hazard ratio [HR]: 0.83; 95% confidence interval [CI]: 0.54 to 1.27; p = 0.39). The 5-year primary composite outcomes were similar for patients receiving DAPT versus aspirin monotherapy respectively, in subgroups with pre-CABG ACSs (15.2% vs. 16.5%; HR: 1.06; 95% CI: 0.53 to 2.10; p = 0.88) and those with stable angina (11.6% vs. 15.8%; HR: 0.82; 95% CI: 0.50 to 1.343; p = 0.42). The composite outcomes of both treatment groups were also similar by SYNTAX score, duration of DAPT therapy, completeness of revascularization, and in off-pump CABG. No treatment-related differences in major bleeding (5.6% vs. 5.7%; HR: 1.00; 95% CI: 0.50 to 1.99; p = 0.99), blood transfusions (4.8% vs. 4.5%; HR: 1.09; 95% CI: 0.51 to 2.34; p = 0.82), or hospitalization for bleeding (2.6% vs. 3.3%; HR: 0.85; 95% CI: 0.34 to 2.17; p = 0.74) were observed between aspirin- and DAPT-treated patients, respectively.

CONCLUSIONS

The use of DAPT in patients with diabetes post-CABG in our cohort was high. Compared with aspirin monotherapy, no associated differences were observed in cardiovascular or bleeding outcomes, suggesting that routine use of DAPT may not be clinically warranted. (Future REvascularization Evaluation in patients with Diabetes mellitus: Optimal management of Multivessel disease [FREEDOM]; NCT00086450).

Perioperative Management of Neurological Conditions

Perioperative care of the patients with neurological diseases can be challenging. Most important consideration is the management and understanding of pathophysiology of these disorders and evaluation of new neurological changes that occur perioperatively. Perioperative generally refers to 3 phases of surgery: preoperative, intraoperative, and postoperative. We have tried to address few commonly encountered neurological conditions in clinical practice, such as delirium, stroke, epilepsy, myasthenia gravis, and Parkinson disease. In this article, we emphasize on early diagnosis and management strategies of neurological disorders in the perioperative period to minimize morbidity and mortality of patients.

Infrainguinal open reconstruction: a review of surgical considerations and expected outcomes

Infrainguinal arterial occlusive disease can lead to potentially disabling and limb-threatening conditions. Revascularization may be indicated for claudication, rest pain, or tissue loss. Although endovascular interventions are becoming more prevalent, open surgeries such as endarterectomy and bypass are still needed and performed regularly. Open reconstruction has been associated with postoperative morbidity, both at the local and at the systemic levels. Local complications include surgical site infections (SSIs 0-5.3%), graft failure (12-60%), and amputation (5.7-27%), and more systemic issues include cardiac (2.6-18.4%), respiratory (2.5%), renal (4%), neurovascular (1.5%), and thromboembolic (0.2-1%) complications. While such outcomes present an additional challenge to the postoperative management of surgical patients, it may be possible to minimize their occurrence through careful risk stratification and preoperative assessment. Therefore, individualized selection of candidates for open repair requires weighing the need for intervention against the likelihood of adverse outcomes based on preoperative risk factors. This review provides an overview of open reconstruction, focusing on identifying the clinical indications for surgery and perioperative morbidity and mortality.

Management of Platelet Disorders and Platelet Transfusions in ICU Patients

Thrombocytopenia or receipt of antiplatelet drugs, with or without bleeding, is a common indication for platelet transfusions in the ICU. However, there is almost no evidence base for these practices other than expert opinion. Also common is use of platelet transfusions prior to invasive procedures or surgery in patients with thrombocytopenia. Likewise, there is no high-quality evidence that such practices are efficacious or safe. Recently, it has become clear that, whether causal or not, patients receiving prophylactic platelet transfusions experience high rates of nosocomial infection, thrombosis, organ failure, and mortality, which increase the urgency and need for randomized trials to assess these practices. Investigational methods of improving the safety and efficacy of platelet transfusions include use of alternate strategies such as antifibrinolytics; use of ABO-identical, leukoreduced, and washed platelet transfusions; and improved storage solutions.

Preoperative aspirin use and acute kidney injury after cardiac surgery: A propensity-score matched observational study

BACKGROUND

The association between preoperative aspirin use and postoperative acute kidney injury (AKI) in cardiovascular surgery is unclear. We sought to evaluate the effect of preoperative aspirin use on postoperative AKI in cardiac surgery.

METHODS

A total of 770 patients who underwent cardiovascular surgery under cardiopulmonary bypass were reviewed. Perioperative clinical parameters including preoperative aspirin administration were retrieved. We matched 108 patients who took preoperative aspirin continuously with patients who stopped aspirin more than 7 days or did not take aspirin for the month before surgery. The parameters used in the matching included variables related to surgery type, patient's demographics, underlying medical conditions and preoperative medications.

RESULTS

In the first seven postoperative days, 399 patients (51.8%) developed AKI, as defined by the Kidney Disease Improving Global Outcomes (KDIGO) criteria and 128 patients (16.6%) required hemodialysis. Most patients took aspirin 100 mg once daily (n = 195, 96.5%) and the remaining 75 mg once daily. Multivariable analysis showed that preoperative maintenance of aspirin was independently associated with decreased incidence of postoperative AKI (odds ratio [OR] 0.46, 95% confidence interval [CI] 0.21-0.98, P = 0.048; after propensity score matching: OR 0.39, 95% CI 0.22-0.67, P = 0.001). Preoperative maintenance of aspirin was associated with less incidence of AKI defined by KDIGO both in the entire and matched cohort (n = 44 [40.7%] vs. 69 [63.9%] in aspirin and non-aspirin group, respectively in matched sample, relative risk [RR] 0.64, 95% CI 0.49, 0.83, P = 0.001). Preoperative aspirin was associated with decreased postoperative hospital stay after matching (12 [9-18] days vs. 16 [10-25] in aspirin and non-aspirin group, respectively, P = 0.038). Intraoperative estimated or calculated blood loss using hematocrit difference and estimated total blood volume showed no difference according to aspirin administration in both entire and matched cohort.

CONCLUSIONS

Preoperative low dose aspirin administration without discontinuation was protective against postoperative AKI defined by KDIGO criteria independently in both entire and matched cohort. Preoperative aspirin was also associated with decreased hemodialysis requirements and decreased postoperative hospital stay without increasing bleeding. However, differences in AKI and hospital stay were not associated with in-hospital mortality.

Consensus Document of the Italian Association of Hospital Cardiologists (ANMCO), Italian Society of Cardiology (SIC), Italian Association of Interventional Cardiology (SICI-GISE) and Italian Society of Cardiac Surgery (SICCH): clinical approach to pharmacologic pre-treatment for patients undergoing myocardial revascularization procedures

The wide availability of effective drugs in reducing cardiovascular events together with the use of myocardial revascularization has greatly improved the prognosis of patients with coronary artery disease. The combination of antithrombotic drugs to be administered before the knowledge of the coronary anatomy and before the consequent therapeutic strategies, can allow to anticipate optimal treatment, but can also expose the patients at risk of bleeding that, especially in acute coronary syndromes, can significantly weigh on their prognosis, even more than the expected theoretical benefit. In non ST-elevation acute coronary syndromes patients in particular, we propose a 'selective pre-treatment' with P2Y12 inhibitors, based on the ischaemic risk, on the bleeding risk and on the time scheduled for the execution of coronary angiography. Much of the problems concerning this issue would be resolved by an early access to coronary angiography, particularly for patients at higher ischaemic and bleeding risk.

Risks and benefits of giving early Aspirin within 6 hours of CABG: A retrospective analysis

BACKGROUND & OBJECTIVE

Antiplatelet drugs are frequently used after coronary artery bypass graft (CABG) surgery to prevent venous graft occlusion. The fear of bleeding complications prevents them to be given early post operatively, which is the time when antiplatelets use confers maximum benefit. Our objective was to determine the effect and influence of early aspirin therapy on fatal and nonfatal bleeding complications and blood requirements after coronary bypass surgery (CABG).

METHODS

The patients who only underwent coronary artery bypass surgery for the first time in the past three years and did not have any bleeding diathesis were retrospectively analyzed from the cardiac surgery database of CPEIC Multan. The patients either received aspirin within six hours of CABG or had it given after 12 hours. The patients were analyzed for mean blood loss and number of blood units transfused. SPSS was used for statistical analysis. P value < 0.05 was considered significant.

RESULTS

Total 281 patients received aspirin within six hours while 326 patients did not. Mean blood loss in early aspirin group was 727ml as compared to 767ml in the other group (p value 0.74). The median number of blood units transfused was 2 (p value 0.98). Our results did not show any statistical difference in both the groups.

CONCLUSION

Aspirin can safely be given early after CABG without the fear of bleeding complications thus conferring the advantage of increased graft patency.

Early Aspirin administration post Coronary Artery Bypass Graft Surgery - Changing hospital culture through a two-cycled audit

“Early Aspirin” or a medium dose of aspirin 6 hours after Coronary Artery Bypass Graft (CABG) Surgery is strongly recommend by international guidelines (EACTS 2007/AHA 2011 guidelines, Level1a evidence) to protect venous graft patency. However, compliance with Early Aspirin prescription at our centre is poor due to long standing hospital cultural practices and lack of awareness.

We completed a two-cycled retrospective audit of 53 (September 2015 Baseline), 65 (January 2016 First Cycle) and 58 (June 2016 Second Cycle) consecutive CABG patients. Interval interventions included educational presentations, educational leaflets/posters, pharmacy liaison and modifications to e-prescription order-sets. Medical, nursing and pharmacy staff were involved in the audit strategies. Early aspirin prescription improved from 23% to 48% to 55% while administration of Early Aspirin improved from 17% to 38% and finally to 48% by second improvement cycle. Significantly, the proportion of patients with omission of early aspirin despite a clear clinical indication, decreased by 50% over the audit period. Important practical considerations were the last dose of anti-platelets preoperatively and amount of of bleeding from mediastinal drains post operatively. A multidisciplinary team based approach led to a 139% improvement in prescription and 182% improvement in administration of “Early Aspirin” after CABG surgery.

Natural history of nonimmune-mediated thrombocytopenia and acute kidney injury in pediatric open-heart surgery

OBJECTIVE

Thrombocytopenia and acute kidney injury (AKI) are common following pediatric cardiac surgery with cardiopulmonary bypass (CPB). However, the relationship between postoperative nadir platelet counts and AKI has not been investigated in the pediatric population. Our objective was to investigate this relationship and examine independent predictors of AKI.

DESIGN

After IRB approval, we performed a retrospective review of the institution's medical records and database.

SETTING

This study was performed at a single institution over a 5-year period.

PATIENTS

We included patients <21 years of age undergoing cardiac surgery with CPB.

INTERVENTIONS

Demographics, laboratory, and surgical characteristics were captured, and clinical event rates were recorded.

MEASUREMENTS

Descriptive statistics were used to evaluate platelet and creatinine distributions. T-tests and chi-squared tests were used to compare characteristics among Acute Kidney Injury Network groups. Multivariable logistic and ordinal logistic regression models were used to determine the association of our predictor of interest, postoperative nadir platelet count and AKI.

RESULTS

Eight hundred and fourteen patients (23% infants and 23% neonates) were included in the analysis. Postoperative platelet counts decreased 48% from baseline reaching a mean nadir value of 150 × 10⁹ ·l^-1 on postoperative day 3. AKI occurred in 37% of patients including 13%, 17%, and 6% with Acute Kidney Injury Network stages 1, 2, and 3, respectively. The magnitude of nadir platelet counts correlated with the severity of AKI. Independent predictors of severity of AKI include nadir platelet counts, CPB time, Aristotle score, patient weight, intra-operative packed red blood cell transfusion, and having a heart transplant procedure.

CONCLUSIONS

In pediatric open-heart surgery, thrombocytopenia and AKI occur commonly following CPB. Our findings show a strong association between nadir platelet counts and the severity of AKI.

Does a Platelet Transfusion Independently Affect Bleeding and Adverse Outcomes in Cardiac Surgery?

Background

Conflicting results have been reported concerning the effect of platelet transfusion on several outcomes. The aim of this study was to assess the independent effect of a single early intraoperative platelet transfusion on bleeding and adverse outcomes in cardiac surgery patients.

Methods

For this observational study, 23,860 cardiac surgery patients were analyzed. Patients who received one early (shortly after cardiopulmonary bypass while still in the operating room) platelet transfusion, and no other transfusions, were defined as the intervention group. By matching the intervention group 1:3 to patients who received no early transfusion with most comparable propensity scores, the reference group was identified.

Results

The intervention group comprised 169 patients and the reference group 507. No difference between the groups was observed concerning reinterventions, thromboembolic complications, infections, organ failure, and mortality. However, patients in the intervention group experienced less blood loss and required vasoactive medication 139 of 169 (82%) versus 370 of 507 (74%; odds ratio, 1.65; 95% CI, 1.05 to 2.58), prolonged mechanical ventilation 92 of 169 (54%) versus 226 of 507 (45%; odds ratio, 1.47; 94% CI, 1.03 to 2.11), prolonged intensive care 95 of 169 (56%) versus 240 of 507 (46%; odds ratio, 1.49; 95% CI, 1.04 to 2.12), erythrocytes 75 of 169 (44%) versus 145 of 507 (34%; odds ratio, 1.55; 95% CI, 1.08 to 2.23), plasma 29 of 169 (17%) versus 23 of 507 (7.3%; odds ratio, 2.63; 95% CI, 1.50–4.63), and platelets 72 of 169 (43%) versus 25 of 507 (4.3%; odds ratio, 16.4; 95% CI, 9.3–28.9) more often compared to the reference group.

Conclusions

In this retrospective analysis, cardiac surgery patients receiving platelet transfusion in the operating room experienced less blood loss and more often required vasoactive medication, prolonged ventilation, prolonged intensive care, and blood products postoperatively. However, early platelet transfusion was not associated with reinterventions, thromboembolic complications, infections, organ failure, or mortality.

Acute coronary angiography after coronary artery bypass grafting

OBJECTIVES

Coronary angiography is the golden standard when myocardial ischemia after CABG occurs. We summarize our experience of acute coronary angiography after CABG.

DESIGN

All 4446 patients (mean age 68 ± 9 years, 22% women) who underwent CABG 2007 to 2012 were included in this retrospective observational study. Incidence, indications, findings, measures of acute angiography after CABG was assessed. Outcome variables were compared between patients who underwent angiography and those who did not.

RESULTS

Eighty-seven patients (2%) underwent acute coronary angiography. Patients undergoing angiography had ECG changes (92%), echocardiographic alterations (48%), hemodynamic instability (28%), angina (15%), and/or arrhythmia (13%). Positive findings were detected in 69% of the cases. Only ECG changes as indication for angiography had a moderate association with positive findings, but the precision increased if other sign(s) of ischemia were present. Thirty-day mortality (7% versus 2%, p = 0.002) was higher and long-term-cumulative survival lower (77% versus 87% at five years, p = 0.043) in angiography patients.

CONCLUSIONS

Acute angiography is a rare event after CABG. Postoperative myocardial ischemia leading to acute coronary angiography is associated with increased short-term and long-term mortality.

Low platelet activity predicts 30 days mortality in patients undergoing heart surgery

Despite advanced techniques and improved clinical outcomes, patient survival following coronary artery bypass grafting (CABG) is still a major concern. Therefore, predicting future CABG mortality represents an unmet medical need and should be carefully explored. The objective of this study is to assess whether pre-CABG platelet activity corresponds with 30 days mortality post-CABG. Retrospective analyses of platelet biomarkers and death at 30 days in 478 heart surgery patients withdrawn from aspirin or/and clopidogrel. Platelet activity was assessed prior to CABG for aspirin (ASPI-test) with arachidonic acid and clopidogrel (ADP-test) utilizing Multiplate impedance aggregometer. Most patients (n = 198) underwent conventional CABG, off-pump (n = 162), minimally invasive (n = 30), artificial valve implantation (n = 48) or valves in combination with CABG (n = 40). There were 22 deaths at 30 days, including 10 in-hospital fatalities. With the cut-off value set below 407 area under curve (AUC) for the ASPI-test, the 30-day mortality was 5.90% for the lower cohort and 2.66% for patients with significantly higher platelet reactivity (P = 0.038). For the ADP-test with a cut-off at 400AUC, the 30-day mortality was 9.68% for the lower cohort and 3.66% for patients with higher platelet reactivity, representing a borderline significant difference (P = 0.046). Aside from the platelet indices, patients who received red blood cell (RBC) concentrate had a highly significant (P < 0.0001) risk of death at 30 days. Both aspirin and clopidogrel tests were useful in predicting 30 days mortality following heart surgery, suggesting the danger of diminished platelet activity prior to CABG in such high-risk patients. These preliminary evidence supports early discontinuation of antiplatelet therapy for elective CABG and requires adequately powered randomized trials to test the hypothesis and potentially improve survival.

Fast-Track Cardiac Anesthesia: Choice of Anesthetic Agents and Techniques

Fast-track cardiac anesthesia (FTCA) incorporates early tracheal extubation, decreased length of intensive care unit (ICU) and hospital stay, and (ideally) should avoid or reduce complications to safely achieve cost-savings. A growing body of evidence from randomized trials has identified many anesthetic interventions that can improve outcome after cardiac surgery. These include new short-acting hypnotic, opioid, and neuromuscular blocking drugs. An effective FTCA program requires the appropriate selection of suitable patients, a lowdose opioid anesthetic technique, early tracheal extubation, a short stay in the ICU, and coordinated perioperative care. It is also dependent on the avoidance of postoperative complications such as excessive bleeding, myocardial ischemia, low cardiac output state, arrhythmias, sepsis, and renal failure. These complications will have a much greater adverse effect on hospital length of stay and healthcare costs. A number of clinical trials have identified interventions that can reduce some of these complications. The adoption of effective treatments into clinical practice should improve the effectiveness of FTCA.

Transfusion of Blood Products Affects Outcome in Cardiac Surgery

There remains controversy as to when patients undergoing cardiac surgery should receive a transfusion and whether a low hematocrit and its treatment with a transfusion of red cells influences outcome. The data related to this controversy are reviewed. Although the risk of known viral transmission is currently low, stored red cells do not function normally, and each unit contains activated inflammatory cells and mediators. These changes cause limited oxygen release, impaired microcirculatory flow, and immune suppression. A number of studies have observed decreased survival associated with transfusions in trauma, coronary artery bypass grafting, and intensive care unit patients. Studies that show an adverse outcome associated with low hematocrit are not definitive, because they fail to distinguish between the impact of low hematocrit per se and the possible adverse effects of transfusion, for what the low hematocrit may simply be a surrogate. The observation that a low hematocrit is associated with an adverse outcome does not necessarily prove that “treatment” of the anemia with a red cell transfusion will improve the outcome. Stored platelets contain a highly activated mixture of platelets with storage lesions and inflammatory mediators. Two retrospective post hoc multifactorial analyses suggest that platelet transfusions are associated with substantial increased morbidity and mortality. Clearly, large prospective studies are required to define the proper trigger for blood product transfusion to balance the adverse effects of anemia and platelet deficiency or dysfunction with the adverse effects of transfusion of blood products on morbidity and mortality associated with cardiac surgery and anesthesia.

Rationale and design of a randomized cluster trial to improve guideline-adherence of secondary preventive drugs prescription after coronary artery bypass grafting in China: Measurement and Improvement Studies of Surgical Coronary Revascularization: Secondary Prevention (MISSION-1) Study

OBJECTIVES

The benefits of secondary preventive drugs after coronary artery bypass grafting have been thoroughly established. However, the prescription rates of these drugs are low at discharge in China. We sought to evaluate the effectiveness of continuous quality improvement with mobile-based interventions for clinicians on improving the guideline-adherence of secondary preventive drugs prescription.

METHODS AND RESULTS

The quality MISSION-1 study is a cluster-randomized controlled trial. We enrolled 60 hospitals with a bypass surgery volume of more than 30 a year and randomly assigned them into the intervention group or the control group in a 1:1 ratio using minimized random grouping. The intervention group undertakes a series of mobile-based interventions, while the control group maintains a routine practice pattern. All sites consecutively register patients who underwent isolated coronary artery bypass grafting and submit in-hospital data. We require supporting documents regarding prescription information at discharge to adjudicate the outcome measures. The estimated sample size of enrolled patients is 9,600. The primary outcome measure is the prescription rate of statins for eligible patients at discharge. The secondary outcome measures are β-blockers, angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, and optimal medical therapy. MISSION-1 study is now recruiting patients.

CONCLUSIONS

The MISSION-1 study has the potential to identify the effectiveness of interventions on improving secondary prevention adherence at discharge after bypass surgery in China and further disseminate findings to other settings to improve the quality of care.

Platelet Counts, Acute Kidney Injury, and Mortality after Coronary Artery Bypass Grafting Surgery

BACKGROUND

Cardiac surgery requiring cardiopulmonary bypass is associated with platelet activation. Because platelets are increasingly recognized as important effectors of ischemia and end-organ inflammatory injury, the authors explored whether postoperative nadir platelet counts are associated with acute kidney injury (AKI) and mortality after coronary artery bypass grafting (CABG) surgery.

METHODS

The authors evaluated 4,217 adult patients who underwent CABG surgery. Postoperative nadir platelet counts were defined as the lowest in-hospital values and were used as a continuous predictor of postoperative AKI and mortality. Nadir values in the lowest 10th percentile were also used as a categorical predictor. Multivariable logistic regression and Cox proportional hazard models examined the association between postoperative platelet counts, postoperative AKI, and mortality.

RESULTS

The median postoperative nadir platelet count was 121 × 10/l. The incidence of postoperative AKI was 54%, including 9.5% (215 patients) and 3.4% (76 patients) who experienced stages II and III AKI, respectively. For every 30 × 10/l decrease in platelet counts, the risk for postoperative AKI increased by 14% (adjusted odds ratio, 1.14; 95% CI, 1.09 to 1.20; P < 0.0001). Patients with platelet counts in the lowest 10th percentile were three times more likely to progress to a higher severity of postoperative AKI (adjusted proportional odds ratio, 3.04; 95% CI, 2.26 to 4.07; P < 0.0001) and had associated increased risk for mortality immediately after surgery (adjusted hazard ratio, 5.46; 95% CI, 3.79 to 7.89; P < 0.0001).

CONCLUSION

The authors found a significant association between postoperative nadir platelet counts and AKI and short-term mortality after CABG surgery.

Indications, algorithms, and outcomes for coronary artery bypass surgery in patients with acute coronary syndromes

For patients with a non-ST-segment elevation acute coronary syndrome (NSTE-ACS), guideline recommendations and treatment pathways focus on revascularization for definitive treatment if the patient is an appropriate candidate. Despite the widespread use of revascularization for NSTE-ACS, most patients undergo a percutaneous coronary intervention, whereas a minority of patients undergo coronary artery bypass grafting. Focusing specifically on the USA, the contemporary utilization, preoperative and perioperative considerations, and outcomes of NSTE-ACS patients undergoing coronary artery bypass grafting have not been comprehensively reviewed.

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.).

Routine postoperative care of patients undergoing coronary artery bypass grafting on cardiopulmonary bypass

The postoperative course of a patient undergoing cardiac surgery (CS) is dictated by a largely predictable set of interactions between disease-specific and therapeutic factors. ICU personnel need to quickly develop a detailed understanding of the patient's current status and how critical care resources can be used to promote further recovery and eventual independence from external support. The goal of this article is to describe a typical operative and postoperative course, with emphasis on the latter, and the diagnostic and therapeutic options necessary for the proper care of these patients. This paper will focus on coronary artery bypass grafting as a model for understanding the course of CS patients; however, many of the principles discussed are applicable to most cardiac surgery patients.

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.

Aspirin in the perioperative period: a review of the recent literature

PURPOSE OF REVIEW

The indications for aspirin (ASA) for both primary and secondary prevention of thrombotic events continue to evolve. We review some of these indications and the recent literature regarding the perioperative administration of ASA.

RECENT FINDINGS

ASA for primary prevention of cardiac ischemia, stroke, cancer, and death remains controversial. When used for primary prevention, ASA may be safely discontinued perioperatively. Patients with coronary or carotid artery stents should continue to receive ASA perioperatively. For patients with ischemic heart disease currently receiving ASA for secondary prevention of cardiac ischemia and stroke undergoing general surgery, orthopedic surgery, ophthalmological surgery, cardiovascular surgery, major vascular surgery, or a urological procedure, continuation of ASA is probably well tolerated, but further study is required. There is no indication to initiate ASA perioperatively in patients with stable ischemic heart disease as the risks outweigh the benefits. Until further data become available, decisions regarding the perioperative continuation of ASA should be made on a case-by-case risk-benefit analysis.

SUMMARY

The continuation or discontinuation of ASA perioperatively remains a complicated issue. Further, well designed trials are needed for additional clarification.

State of the Art: Medical treatment of aspirin exacerbated respiratory disease (AERD)

Aspirin exacerbated respiratory disease (AERD) is characterized as adult onset asthma, nasal polyps, chronic rhinosinusitis, and hypersensitivity to a cyclooxygenase-1 (COX-1) inhibitor, viz aspirin or nonsteroidal antiinflammatory drugs (NSAIDs). The method for diagnosing AERD is with aspirin challenge, and treatment includes aspirin desensitization followed by continued daily aspirin. Although oral challenge has been the mainstay in the United States, lysyl-aspirin has been validated as a diagnostic tool for aspirin-sensitive asthma and will be discussed further in this article. The challenges with aspirin therapy surrounding endoscopy and perioperative aspirin therapy will be discussed. Additionally, daily aspirin therapy is not for everyone. Aspirin is relatively contraindicated in those with a history of gastrointestinal bleed and an absolute contraindication in pregnancy. Aspirin desensitization and subsequent treatment has been shown to be highly effective for AERD.

An Overview of Meta-Analyses of Danhong Injection for Unstable Angina

Objective. To systematically collect evidence and evaluate the effects of Danhong injection (DHI) for unstable angina (UA). Methods. A comprehensive search was conducted in seven electronic databases up to January 2015. The methodological and reporting quality of included studies was assessed by using AMSTAR and PRISMA. Result. Five articles were included. The conclusions suggest that DHI plus conventional medicine treatment was effective for UA pectoris treatment, could alleviate symptoms of angina and ameliorate electrocardiograms. Flaws of the original studies and systematic reviews weaken the strength of evidence. Limitations of the methodology quality include performing an incomprehensive literature search, lacking detailed characteristics, ignoring clinical heterogeneity, and not assessing publication bias and other forms of bias. The flaws of reporting systematic reviews included the following: not providing a structured summary, no standardized search strategy. For the pooled findings, researchers took statistical heterogeneity into consideration, but clinical and methodology heterogeneity were ignored. Conclusion. DHI plus conventional medicine treatment generally appears to be effective for UA treatment. However, the evidence is not hard enough due to methodological flaws in original clinical trials and systematic reviews. Furthermore, rigorous designed randomized controlled trials are also needed. The methodology and reporting quality of systematic reviews should be improved.

Predicting Bleeding Risk by Platelet Function Testing in Patients Undergoing Heart Surgery

BACKGROUND

Predicting bleeding events in patients with coronary artery bypass grafting (CABG) represents an unmet medical need that may improve CABG outcomes.

HYPOTESIS

To assess the potential link between platelet function testing and bleeding risk in patients undergoing CABG.

METHODS

Platelet aggregation and clinical outcomes in 478 patients treated with aspirin and/or clopidogrel were retrospectively analyzed. Platelet activity was assessed prior to CABG with arachidonic acid (ASPI Test), and adenosine diphosphate(ADP Test) utilizing multiple-electrode aggregometry.

RESULTS

In the study group of 478 patients, mean age was 65.2±15.2 years; 138 were women. The majority of patients (n = 198) underwent on-pump surgery, with 162 undergoing off-pump and 30 undergoing minimally invasive surgery. Forty-eight patients received artificial valve implantation alone, and 40 received valve implantation in combination with CABG. The analysis of the entire pool revealed that an ASPI test value <407 area under curve per minute (AUC*min) may be useful in predicting postoperative drainage. In CABG patients only, an ASPI test value <271 AUC*min predicted the need for red blood cell concentrate transfusion following surgery. In patients who stopped clopidogrel for up to 5 days before surgery, the ADP test failed to exhibit prognostic utility for predicting bleeding risk.

CONCLUSIONS

In patients undergoing heart surgery, an ASPI test value <407 AUC*min may predict higher postoperative drainage, whereas <271 AUC*min may be linked to postoperative use of red blood cell concentrate.

Perioperative stroke

PURPOSE

Perioperative stroke is associated with significant morbidity and mortality, with an incidence that may be underappreciated. In this review, we examine the significance, pathophysiology, risk factors, and evidence-based recommendations for the prevention and management of perioperative stroke.

SOURCE

This is a narrative review based on literature from the PubMed database regarding perioperative stroke across a broad surgical population. The Society for Neuroscience in Anesthesiology and Critical Care recently published evidence-based recommendations for perioperative management of patients at high risk for stroke; these recommendations were analyzed and incorporated into this review.

PRINCIPAL FINDINGS

The incidence of overt perioperative stroke is highest in patients presenting for cardiac and major vascular surgery, although preliminary data suggest that the incidence of covert stroke may be as high as 10% in non-cardiac surgery patients. The pathophysiology of perioperative stroke involves different pathways. Thrombotic stroke can result from increased inflammation and hypercoagulability; cardioembolic stroke can result from disease states such as atrial fibrillation, and tissue hypoxia from anemia can result from the combination of anemia and beta-blockade. Across large-scale database studies, common risk factors for perioperative stroke include advanced age, history of cerebrovascular disease, ischemic heart disease, congestive heart failure, atrial fibrillation, and renal disease. Recommendations for prevention and management of perioperative stroke are evolving, though further work is needed to clarify the role of proposed modifiable risk factors such as perioperative anticoagulation, antiplatelet therapy, appropriate transfusion thresholds, and perioperative beta-blockade.

CONCLUSIONS

Perioperative stroke carries a significant clinical burden. The incidence of perioperative stroke may be higher than previously recognized, and there are diverse pathophysiologic mechanisms. There are many opportunities for further investigation of the pathophysiology, prevention, and management of perioperative stroke.

Reduced aspirin responsiveness as assessed by impedance aggregometry is not associated with adverse outcome after cardiac surgery in a small low-risk cohort

Reduced aspirin responsiveness (i.e. persistent high platelet reactivity in platelet function testing) might be associated with increased risk of myocardial ischemia and cardiac mortality in patients with coronary disease. However, the impact in patients undergoing coronary artery bypass grafting (CABG) is unclear. The aim of this prospective cohort study was to evaluate the predictive value of reduced aspirin responsiveness on cardiac and thromboembolic events in patients undergoing elective isolated CABG surgery with aspirin intake until at least two days before surgery. We included 304 patients in this prospective single-center cohort study. Impedance platelet aggregometry (Multiplate®) was performed directly before and on the first day after surgery. Reduced aspirin responsiveness was defined as area under the curve in ASPItest (AUCASPI) ≥300 U. The primary outcome was a composite of all-cause mortality and/or major adverse cardiac or thromboembolic events within 1 year. Reduced aspirin responsiveness was found in 13 and 24% of patients pre and postoperatively, respectively. There was no difference in the outcomes between patients with normal and reduced aspirin responsiveness in the preoperative measurement (log-rank test, p = 0.540). Multivariate analysis including logistic EuroSCORE I and postoperative troponin T levels did not show any association of reduced aspirin responsiveness with adverse outcome (hazard ratio, 0.576; (95% CI 0.128-2.585; p = 0.471). Similarly, postoperative reduced aspirin responsiveness was not associated with adverse events. To conclude, reduced aspirin responsiveness as evaluated by Multiplate® platelet function analyzer was not associated with increased incidence of major adverse cardiac and thromboembolic events and mortality after CABG surgery.

The Effect of Aspirin on Bleeding and Transfusion in Contemporary Cardiac Surgery

OBJECTIVE

Despite evidence that preoperative aspirin improves outcomes in cardiac surgery, recommendations for aspirin use are inconsistent due to aspirin's anti-platelet effect and concern for bleeding. The purpose of this study was to investigate preoperative aspirin use and its effect on bleeding and transfusion in cardiac surgery.

METHODS

This retrospective study involved consecutive patients (n=1571) who underwent CABG, valve, or combined CABG and valve surgery at a single center between March 2007 and July 2012. Of all patients, 728 met the inclusion criteria and were divided into two groups: those using (n=603) or not using (n=125) aspirin within 5 days of surgery. Data were collected on chest tube drainage, re-operation for bleeding, and transfusion of red blood cells (RBCs), fresh frozen plasma (FFP), and platelets.

RESULTS

No significant difference was observed between the two groups in chest tube drainage or re-operation for bleeding. An increase in patients transfused with RBCs was observed in the aspirin group (61.9 vs 51.2%, adjusted OR 1.77, p=0.027); however, among those transfused RBCs, no significant difference in mean units transfused or massive transfusion was observed. No significant difference was seen in transfusion requirement of FFP or platelets.

CONCLUSIONS

In patients undergoing CABG, valve, or combined CABG/valve surgery, preoperative aspirin, within 5 days of surgery, was associated with an increased probability of receiving an RBC transfusion. Preoperative aspirin was not associated with an increase in chest tube drainage, re-operation for bleeding complications, or transfusion of FFP or platelets.

Stroke associated with coronary artery bypass grafting

While coronary artery bypass grafting (CABG) has been playing a significant role in the revascularization for ischemic heart disease, neurological complications associated with CABG have been a primary concern. Stroke, although the incidence is low, is one of the most devastating complication of CABG. Many studies have identified the risk factors for stroke with CABG, such as prior stroke, carotid artery stenosis, aortic atherosclerosis, atrial fibrillation and cardiopulmonary bypass. Various rational approaches focusing on individual risk factor have been proposed for the stroke. Prophylactic carotid revascularization is an important strategy, and the diagnosis of carotid stenosis has to be established correctly. Prevention of emboli from aortic plaque is also an essential issue. Intraoperative monitoring with transesophageal or epiaortic ultrasound is useful to identify mobile atheromatous plaques and to select appropriate aortic manipulations. Maintenance of cerebral blood flow and blood pressure during cardiopulmonary bypass might be critical issues. Besides, there are conflicting two opinions regarding off-pump CABG; one supports an efficiency for the prevention of stroke while the other advocates no effect. This discrepancy might be explained by the difference of the risk of stroke in the population of the individual study and by the variation of the percentage of aortic clamping or aortic anastomosis in each study. Pharmaceutical therapies such as statin, preventive medication for atrial fibrillation, or antiplatelet are promising methods. Although it is hard to decrease the incidence of the stroke with any single countermeasure, sustained effort should be continued to overcome the stroke associated with CABG.