The Evolution of Antiplatelet Therapy After Percutaneous Coronary Interventions: A 40-Year Journey

Antiplatelet therapy has a critical role to play in the successful management of patients undergoing percutaneous coronary intervention (PCI). Over the past 40 years, a multitude of participants worldwide have been enrolled in trials evaluating the impact of antiplatelet agents on clinical outcomes. The use of aspirin in unstable angina in the Canadian Aspirin trial was key to establishing the benefit of aspirin in acute coronary syndrome. The Clopidogrel in Unstable Angina to Prevent Recurrent Events (CURE) trial demonstrated that the P2Y12 inhibitor clopidogrel, when added to aspirin, reduced major cardiovascular events. While the use of antiplatelet agents in coronary artery disease antedates the introduction of PCI and remains the cornerstone of secondary prevention of atherosclerotic cardiovascular disease, strategies aiming to optimise their best use are still constantly evolving. In this review, the major randomised trials shaping current clinical practice for the use of aspirin and P2Y12 inhibitors in patients undergoing PCI are summarised, with a focus on aspirin-free strategies and on the role of P2Y12 inhibitor treatment before PCI, two major topics of ongoing investigation that are critical to patient care but that are not addressed in current practice guidelines. Multiple questions remain regarding the use of antiplatelet agents after PCI, including the personalisation of dosing, intensity, pharmacologic formulation, and duration of antiplatelet therapy based on individual patient characteristics and the optimal treatment of patients at high bleeding risk.

Regional anaesthesia in patients on antithrombotic drugs: Joint ESAIC/ESRA guidelines

BACKGROUND

Bleeding is a potential complication after neuraxial and peripheral nerve blocks. The risk is increased in patients on antiplatelet and anticoagulant drugs. This joint guideline from the European Society of Anaesthesiology and Intensive Care and the European Society of Regional Anaesthesia aims to provide an evidence-based set of recommendations and suggestions on how to reduce the risk of antithrombotic drug-induced haematoma formation related to the practice of regional anaesthesia and analgesia.

DESIGN

A systematic literature search was performed, examining seven drug comparators and 10 types of clinical intervention with the outcome being peripheral and neuraxial haematoma. Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used for assessing the methodological quality of the included studies and for formulating recommendations. A Delphi process was used to prepare a clinical practice guideline.

RESULTS

Clinical studies were limited in number and quality and the certainty of evidence was assessed to be GRADE C throughout. Forty clinical practice statements were formulated. Using the Delphi-process, strong consensus (>90% agreement) was achieved in 57.5% of recommendations and consensus (75 to 90% agreement) in 42.5%.

DISCUSSION

Specific time intervals should be observed concerning the adminstration of antithrombotic drugs both prior to, and after, neuraxial procedures or those peripheral nerve blocks with higher bleeding risk (deep, noncompressible). These time intervals vary according to the type and dose of anticoagulant drugs, renal function and whether a traumatic puncture has occured. Drug measurements may be used to guide certain time intervals, whilst specific reversal for vitamin K antagonists and dabigatran may also influence these. Ultrasound guidance, drug combinations and bleeding risk scores do not modify the time intervals. In peripheral nerve blocks with low bleeding risk (superficial, compressible), these time intervals do not apply.

CONCLUSION

In patients taking antiplatelet or anticoagulant medications, practitioners must consider the bleeding risk both before and after nerve blockade and during insertion or removal of a catheter. Healthcare teams managing such patients must be aware of the risk and be competent in detecting and managing any possible haematomas.

2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The guideline for coronary artery revascularization replaces the 2011 coronary artery bypass graft surgery and the 2011 and 2015 percutaneous coronary intervention guidelines, providing a patient-centric approach to guide clinicians in the treatment of patients with significant coronary artery disease undergoing coronary revascularization as well as the supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from May 2019 to September 2019, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, CINHL Complete, and other relevant databases. Additional relevant studies, published through May 2021, were also considered. Structure: Coronary artery disease remains a leading cause of morbidity and mortality globally. Coronary revascularization is an important therapeutic option when managing patients with coronary artery disease. The 2021 coronary artery revascularization guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with coronary artery disease who are being considered for coronary revascularization, with the intent to improve quality of care and align with patients' interests.

2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The guideline for coronary artery revascularization replaces the 2011 coronary artery bypass graft surgery and the 2011 and 2015 percutaneous coronary intervention guidelines, providing a patient-centric approach to guide clinicians in the treatment of patients with significant coronary artery disease undergoing coronary revascularization as well as the supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from May 2019 to September 2019, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, CINHL Complete, and other relevant databases. Additional relevant studies, published through May 2021, were also considered.

STRUCTURE

Coronary artery disease remains a leading cause of morbidity and mortality globally. Coronary revascularization is an important therapeutic option when managing patients with coronary artery disease. The 2021 coronary artery revascularization guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with coronary artery disease who are being considered for coronary revascularization, with the intent to improve quality of care and align with patients' interests.

Platelet Function Tests Predicting the Efficacy and Safety of Aspirin Secondary Prevention

OBJECTIVE

To precisely prevent stroke, we evaluated three platelet function tests and their associations with clinical outcomes in ischemic stroke patients.

METHODS

On-treatment platelet reactivity of acute minor stroke patients taking aspirin plus clopidogrel was tested by light transmittance aggregometry (LTA), thromboelastography (TEG) and platelet function analyzer (PFA). Mann-Whitney U tests and receiver operating characteristic (ROC) curve analysis were used to assess their associations with recurrent events and clinical outcome prediction.

RESULTS

127 acute minor stroke patients were stringently selected and followed for 13 months. Eight patients (6.3%) self-reported the recurrence and 13 (10.2%) patients self-reported bleeding. Recurrent patients displayed significantly higher on-treatment platelet reactivity when measured with LTA (p = 0.030) and PFA (p < 0.001). Further ROC analysis demonstrated that LTA and PFA had modest-to-fair ability to predict stroke recurrence (LTA: area under the curve [AUC], 0.765; 95% CI, 0.584-0.945, PFA: AUC, 0.832; 95% CI, 0.658-1.000). However, TEG (measured by the platelet inhibition rate) could not detect the difference between recurrent patients and non-recurrent patients (p = 0.515) and predict recurrent events (AUC, 0.569; 95% CI, 0.368-0.770). None of the tests were associated with bleeding except for PFA (p < 0.001), with AUC of PFA reaching 0.772 (0.726-0.818).

CONCLUSIONS

Of the three tests assessed, the predictive accuracies of PFA and LTA were satisfying for aspirin secondary prevention, while TEG's performance was poor. Only PFA could provide accurate prognostic information for bleeding.

Duration of Dual Antiplatelet Therapy in Patients With Acute Coronary Syndrome Treated With New Generation Stents: A Meta-Analysis of Randomized Controlled Trials

Background and Objective: The optimum duration of dual antiplatelet therapy (DAPT) remains uncertain in patients with acute coronary syndrome treated with new generation stents. This meta-analysis was performed to investigate ischemia and bleeding outcomes with different DAPT strategies.

Methods: PubMed, Embase, Cochrane and Web of science from inception to May 27, 2020, were systematically searched. Randomized controlled trials were included to compare short-term (6 months or less) with standard (12 months) DAPT in patients with acute coronary syndrome treated with new generation stents. The primary endpoints were myocardial infarction, definite or probable stent thrombosis and major bleeding. The secondary endpoints included all-cause death, cardiovascular death, stroke, target vessel revascularization and net adverse clinical events. Random effect model and fixed effect model were used to calculate the odds ratio (OR) and 95% confidence interval (CI) of each endpoint.

Results: Four randomized controlled trials and seven subgroup analyses of larger randomized controlled trials, including a total of 21,344 patients with acute coronary syndrome, met our inclusion criteria. The shorter DAPT was associated with significantly lower major bleeding compared with the standard DAPT (OR 0.71, 95% CI 0.56–0.90, P = 0.005, I² = 25%), while without increasing the risk of myocardial infarction (OR 1.18, 0.88–1.58, P = 0.28, I² = 20%), definite or probable stent thrombosis (OR 1.60, 0.98–2.59, P = 0.06, I² = 0%). No significantly difference was observed in the risk of all-cause death (OR 0.96, 0.72–1.27, P = 0.76, I² = 2%), cardiovascular death (OR 0.91, 0.62–1.33, P = 0.62, I² = 0%), stroke (OR 0.84, 0.54–1.30, P = 0.43, I² = 0%), target vessel revascularization (OR 1.14, 0.84–1.55, P = 0.41, I² = 8%), and net adverse clinical events (OR 0.93, 0.80–1.07, P = 0.3, I² = 18%) between the two groups.

Conclusions: In patients with acute coronary syndrome treated with new generation stents, the shorter DAPT leads to a marked reduction in the risk of major bleeding compared with the standard DAPT. This benefit is achieved without increasing the risk of mortality or ischemic outcomes. The study protocol was registered in PROSPERO (CRD42020189871).

Novel Dual Therapy: A Paradigm Shift in Anticoagulation in Patients of Atrial Fibrillation Undergoing Percutaneous Coronary Intervention

Patients with atrial fibrillation (AF) on long-term oral anticoagulation (OAC) either have underlying coronary artery disease or suffer from acute coronary syndromes necessitating a percutaneous coronary intervention (PCI). In such a scenario, an amalgamation of antiplatelet and antithrombotic therapy (conventionally called as “triple therapy”) is obligatory for preventing coronary ischemia and stroke. But such ischemic benefits are accrued at the cost of increased bleeding. We also now know that bleeding events following PCI are related to increased mortality. Balancing the bleeding and ischemic risks is often a clinical dilemma. With the advent of novel oral anticoagulants (NOAC's) with preserved efficacy and attenuated bleeding rates, anticoagulation in AF is undergoing paradigm shift. The spotlight is now shifting from conventional triple therapy (vitamin-K antagonist + dual antiplatelet therapy [VKA + DAPT]) to novel dual therapy (NOAC + single antiplatelet therapy [SAPT]) in situation of anticoagulated AF patients undergoing PCI. Such a strategy aims to ameliorate the higher bleeding risk with conventional VKA's while retaining the ischemic benefits. In this review, we briefly discuss the need for combination therapy, trials of novel dual therapy, strategies for mitigating bleeding, the current guidelines, and the future perspectives in AF undergoing PCI with stent(s).

Effect of Acetylsalicylic Acid Dose and Time Discontinued Preoperatively on Outcomes After Total Knee and Hip Arthroplasty

The purpose of this study was to determine if acetylsalicylic acid (ASA) dose or time discontinued preoperatively affected surgical outcomes in total joint arthroplasty (TJA). The authors hypothesized that ASA worsens surgical outcomes in patients receiving higher doses and in those who discontinue ASA closer to the operative date. A total of 2853 TJAs (1802 primary total knee arthroplasties and 1051 total hip arthroplasties) performed at a tertiary medical center were reviewed. Postoperative outcomes of patients receiving ASA prior to TJA, dosing of ASA (81 mg or 325 mg) preoperatively and postoperatively, and the time of preoperative discontinuation (no ASA, <4 days, <7 days, and 7 or more days) were compared. Preoperative ASA was a risk factor for readmission (odds ratio [OR], 1.86; P<.001) and 90-day postoperative events (OR, 1.26; P=.004). Among patients receiving ASA, the dose was not a risk factor for any of the studied outcomes. Discontinuing ASA 7 or more days prior to TJA was protective for hematomas (OR, 0.64; P=.038), emergency department visits (OR, 0.79; P=.006), readmission (OR, 0.65; P<.001), and 90-day postoperative events (OR, 0.72; P<.001). These outcomes had a time effect: the risk was greater for those who discontinued therapy closer to the operative date. Patients who discontinued ASA 7 or more days prior to TJA had a lower incidence of hematomas, emergency department visits, readmissions, and 90-day postoperative events. This study's findings support discontinuing ASA at least 7 days prior to TJA. [Orthopedics. 2019; 42(5):286-293].

In-hospital Outcomes of Patients with ST-segment Elevation Myocardial Infarction who were Intubated before Primary Percutaneous Intervention: Experience of a tertiary center

OBJECTIVES

ST-segment elevation myocardial infarction (STEMI) complicated by respiratory failure is associated with a greater number of in-hospital and out-of-hospital adverse cardiovascular events (CVEs). The aim of this study was to analyze in-hospital outcomes and the factors affecting the outcomes of intubated patients diagnosed with STEMI who underwent primary percutaneous coronary intervention (pPCI) at a single tertiary care center.

METHODS

The data of 592 patients diagnosed with acute STEMI who were admitted to the emergency department between May 2017 and January 2019 and subsequently underwent pPCI were retrospectively reviewed. Cardiovascular risk factors as well as biochemical and angiographic characteristics of patients who were intubated in the emergency room or ambulance due to cardiac arrest and those who were not intubated were compared. Adverse CVEs were defined as in-hospital death, cerebrovascular stroke, and acute stent thrombosis.

RESULTS

A total of 60 patients (70% male; mean age: 63.6±14.0 years) who were intubated and 532 non-intubated patients (81% male; mean age: 60.2±12.1 years) were included in the study. The angiographic features of the 2 groups were similar. An adverse CVE was experienced by 43.3% of the intubated patients and 3.6% of the non-intubated patients. Multivariate analysis indicated that age (odds ratio [OR]: 1.065; p<0.001), serum lactate level (OR: 1.308; p<0.001), and left ventricle ejection fraction (OR: 0.946; p<0.001) were independent predictors of in-hospital adverse CVE in the intubated patient group.

CONCLUSION

The results of this single-center study showed that 1 in 10 patients hospitalized with STEMI were intubated, and approximately 4 in 10 intubated STEMI patients had an in-hospital CVE.

Pros and Cons of Aspirin Prophylaxis for Prevention of Cardiovascular Events in Kidney Transplantation and Review of Evidence

Kidney transplant recipients have traditional and nontraditional risk factors which can lead to coronary artery disease and sudden death with a functional graft loss. Aspirin has been used traditionally for prevention of cardiovascular and cerebrovascular accidents. It has beneficial effects in secondary prevention of cardiovascular events in general population. Its use for primary prophylaxis is still disputed. Bleeding and theoretical risk of nephrotoxicity are the major concerns about its use. The data on aspirin in kidney transplant population is sparse. This review will focus on various pros and cons of aspirin use for prevention of cardiovascular events in kidney transplant recipients and a way forward.

Periprocedural Myocardial Infarction in Contemporary Practice

"Periprocedural myocardial infarction (MI) occurs infrequently in the current era of percutaneous coronary interventions (PCI) and is associated with an increased risk of mortality and morbidity. Periprocedural MI can occur due to acute side branch occlusion, distal embolization, slow flow or no reflow phenomenon, abrupt vessel closure, and nonidentifiable mechanical processes. Therapeutic strategies to reduce the risk of periprocedural MI include dual antiplatelet therapy, intravenous cangrelor in the periprocedural setting, intravenous glycoprotein IIb/IIIa inhibitor in high-risk patients, anticoagulation with unfractionated heparin, low-molecular-weight heparin or bivalirudin, and embolic protection devices during saphenous vein graft interventions."

Incidence and prognostic impact of post discharge bleeding post acute coronary syndrome within an outpatient setting: a systematic review

OBJECTIVE

The primary objective was to determine the incidence of bleeding events post acute coronary syndrome (ACS) following hospital discharge. The secondary objective was to determine the prognostic impact of bleeding on mortality, major adverse cardiovascular events (MACE), myocardial re-infarction and rehospitalisation in the postdischarge setting.

DESIGN

A narrative systematic review.

DATA SOURCE

Medline, Embase, Amed and Central (Cochrane) were searched up to August 2018.

STUDY SELECTION

For the primary objective, randomised controlled trials (RCT) and observational studies reporting on the incidence of bleeding post hospital discharge were included. For the secondary objective, RCTs and observational studies that compared patients with bleeding versus those without bleeding post hospital discharge vis-à-vis mortality, MACE, myocardial re-infarction and rehospitalisation were included.

RESULTS

53 studies (36 observational studies and 17 RCTs) with a combined cohort of 714 458 participants for the primary objectives and 187 317 for the secondary objectives were included. Follow-up ranged from 1 month to just over 4 years. The incidence of bleeding within 12 months post hospital discharge ranged from 0.20% to 37.5% in observational studies and between 0.96% and 39.4% in RCTs. The majority of bleeds occurred in the initial 3 months after hospital discharge with bruising the most commonly reported event. Major bleeding increased the risk of mortality by nearly threefold in two studies. One study showed an increased risk of MACE (HR 3.00,95% CI 2.75 to 3.27; p<0.0001) with bleeding and another study showed a non-significant association with rehospitalisation (HR 1.20,95% CI 0.95 to 1.52; p=0.13).

CONCLUSION

Bleeding complications following ACS management are common and continue to occur in the long term after hospital discharge. These bleeding complications may increase the risk of mortality and MACE, but greater evidence is needed to assess their long-term effects.

PROSPERO REGISTRATION NUMBER

CRD42017062378.

Evaluation of the Patterns of Non-Adherence to Anti-Platelet Regimens in Stented Patients Bleeding Score for Predicting the Long-term Out-of-hospital Bleeding Risk in Chinese Patients after Percutaneous Coronary Intervention

Background

The Patterns of Non-Adherence to Anti-Platelet Regimens in Stented Patients (PARIS) bleeding score is a novel score for predicting the out-of-hospital bleeding risk after percutaneous coronary intervention (PCI). However, whether this score has the same value in non-European and American populations is unclear. This study aimed to assess the PARIS bleeding score's predictive value of bleeding in patients after PCI in the Chinese population.

Methods

We performed a prospective, observational study of 10,724 patients who underwent PCI from January to December 2013, in Fuwai Hospital, China. We defined the primary end point as major bleeding (MB) according to Bleeding Academic Research Consortium definition criteria including Type 2, 3, or 5. The predictive value of the PARIS bleeding score was assessed with the area under the receiver operating characteristic (AUROC) curve.

Results

Of 9782 patients, 245 (2.50%) MB events occurred during the 2 years of follow-up. The PARIS bleeding score was significantly higher in the MB group than that of non-MB group (4.00 [3.00, 5.00] vs. 3.00 [2.00, 5.00], Z = 3.71, P < 0.001). According to risk stratification of the PARIS bleeding score, the bleeding risk in the intermediate- and high-risk groups was 1.50 times (hazard ratio [HR]: 1.50; 95% confidence interval [CI]: 1.160-1.950; P = 0.002) and 2.27 times higher (HR: 2.27; 95% CI: 1.320-3.900; P = 0.003) than that in the low-risk group. The PARIS bleeding score showed a moderate predictive value for MB in the overall population (AUROC: 0.568, 95% CI: 0.532-0.605; P < 0.001) and acute coronary syndrome (ACS) subgroup (AUROC: 0.578, 95% CI: 0.530-0.626; P = 0.001) and tended to be predictive in the non-ACS subgroup (AUROC: 0.556, 95% CI: 0.501-0.611; P = 0.054).

Conclusion

The PARIS bleeding score shows good clinical value for risk stratification and has a significant, but relatively limited, prognostic value for out-of-hospital bleeding in the Chinese population after PCI.

Antiplatelet and anticoagulation therapy during percutaneous coronary interventions: A review for the interventionalist

Pharmacotherapy for percutaneous coronary interventions is essential to optimize the balance between thrombosis and bleeding. Currently, choices abound for the selection of antiplatelet and anticoagulation therapies during percutaneous intervention (PCI). This review article discusses the mechanisms, pharmacokinetics/dynamics, and clinical data behind the various pharmacotherapies including; aspirin, thienopyridines, glycoprotein IIb/IIIa inhibitors, vorapaxar, heparin, direct thrombin inhibitors, and factor Xa inhibitors.

Aspirin withdrawal in patients treated with ticagrelor presenting with non-ST elevation myocardial infarction

Essentials Strong P2Y12 blockade may cause platelet inhibition that is only minimally enhanced by aspirin. We evaluated aspirin withdrawal on platelet reactivity in ticagrelor treated patients. Aspirin withdrawal resulted in increased platelet reactivity to arachidonic acid. Aspirin withdrawal caused little difference in adenosine diphosphate-induced platelet aggregation.

SUMMARY

Background Recent studies have shown that the thromboxane A2 -dependent pathway is dependent on the ADP-P2Y12 pathway, and that strong P2Y12 receptor blockade alone causes inhibition of platelet aggregation that is minimally enhanced by aspirin. Data from the PLATO trial suggested that, among ticagrelor-treated patients, high-dose versus low-dose (< 100 mg day-1 ) aspirin is associated with an increased risk fof ischemic events. Objectives To evaluate the impact of aspirin withdrawal on platelet reactivity in acute coronary syndrome (ACS) patients treated with a potent P2Y12 blocker. Patients/Methods This was a current prospective, randomized, placebo-controlled, double-blind, cross-over study. The study population comprised 22 consecutive ACS patients who underwent percutaneous coronary intervention and were treated with aspirin (100 mg day-1 ) and ticagrelor. Thirty days post-ACS, open-label aspirin was stopped, and patients were randomized to either blinded aspirin or placebo for 2 weeks, with each patient crossing over to the other arm for an additional 2 weeks. Platelet reactivity to arachidonic acid and ADP determined with light-transmission aggregometry (LTA) and VerifyNow was evaluated at baseline, and 2 weeks and 4 weeks later. Results Aspirin withdrawal resulted in an increase in arachidonic-acid induced platelet reactivity as determined with both LTA (77.0% ± 11.3% versus 20.8% ± 4.4%) and VerifyNow (607.7 ± 10.6 aspirin reaction units [ARU] versus 408.5 ± 14.4 ARU). Platelet response to ADP, as determined with both LTA and VerifyNow, did not differ with either aspirin or placebo (32.9% ± 2.6% versus 35.8% ± 3.6%, and 33.5 ± 6.4 P2Y12 reaction units (PRU) versus 29.6 ± 5.7 PRU, respectively). Conclusions Aspirin withdrawal early post-ACS results in increased platelet reactivity in response to arachidonic acid, despite concomitant treatment with the potent P2Y12 blocker ticagrelor.

Feasibility of coronary fractional flow reserve with dual anti-platelet therapy in low risk coronary lesions without systemic anticoagulation-results of the SMART-FFR study

BACKGROUND

Fractional flow reserve (FFR) is used to assess the functional significance of coronary artery stenoses. The optimal anti-thrombotic regimen for FFR has not been studied.

PURPOSE

The goal of this study was to determine whether FFR could be safely performed in Type A coronary lesions, using only upstream dual anti-platelet therapy (DAT) with aspirin and clopidogrel, compared with DAT plus anticoagulation in low risk coronary lesions.

METHODS/MATERIALS

Two hundred patients undergoing FFR for Type A intermediate coronary lesions were blindly randomized into two groups of 100 patients each. Group 1: Upstream DAT, without intra-procedural anti-coagulation and Group 2: Upstream DAT plus intra-procedural bivalirudin. The primary end-points were any coronary thrombotic complications during the index hospital stay, and a composite end-point of any major adverse cardiovascular events (MACE) at 30-days. Secondary end-points included post-procedure troponin levels and TIMI major and minor bleeding scores.

RESULTS

There were no thrombotic complications reported. At 30-days, two MACE occurred in Group 1, and three in Group 2 (p=0.83). No difference was seen in the post-procedure troponin levels (p=0.72), or TIMI bleeding scores study between groups (p=093).

CONCLUSIONS

This initial study evaluating a simplified anti-thrombotic regimen for FFR, suggests that FFR can be performed in low risk coronary lesions using DAT without the need for intra-procedural anticoagulation, with similar results as DAT plus anticoagulation with bivalirudin. Further research in this area is needed to determine the optimal and most cost-effective anti-thrombotic regimen for FFR calculation.

A randomized clinical trial comparing long-term clopidogrel vs aspirin monotherapy beyond dual antiplatelet therapy after drug-eluting coronary stent implantation: Design and rationale of the Harmonizing Optimal Strategy for Treatment of coronary artery stenosis-Extended Antiplatelet Monotherapy (HOST-EXAM) trial

Percutaneous coronary intervention (PCI) has been developed by drug-eluting stent (DES), but stent implantation has brought the issue of stent thrombosis and optimal antiplatelet therapy. Guidelines recommend at least 6- to 12 months of dual antiplatelet therapy (DAPT) with aspirin and a P2Y₁₂ receptor inhibitor such as clopidogrel. Beyond DAPT after PCI with DES, however, there has been still a debate for antiplatelet regimen. Therefore, we report on the upcoming HOST-EXAM trial (NCT02044250), which will evaluate the efficacy and safety of aspirin and clopidogrel monotherapies beyond DAPT after DES implantation.

TRIAL DESIGN

The HOST-EXAM is a prospective, randomized, open-label, multicenter, comparative effectiveness trial, to compare between clopidogrel (75 mg once daily) and aspirin (100 mg once daily) as long-term antiplatelet agents. A total of 5,530 patients with no clinical events during combined antiplatelet therapy for 12±6 months after index PCI will be screened, enrolled, and randomized to either group (1:1 ratio) receiving antiplatelet monotherapy for 2 years. The primary endpoint will be the rate of clinical events defined as a composite of all-cause death, nonfatal myocardial infarction, stroke, readmission due to acute coronary syndrome, or major bleeding at 24 months after randomization.

CONCLUSIONS

The HOST-EXAM will be the first large-scale randomized controlled study to directly compare the efficacy and safety of long-term antiplatelet monotherapy beyond DAPT after DES implantation. This study will provide clinical evidence to establish optimal regimen for long-term antiplatelet therapy after DES implantation.

Clinicians' Reports in Electronic Health Records Versus Patients' Concerns in Social Media: A Pilot Study of Adverse Drug Reactions of Aspirin and Atorvastatin

INTRODUCTION

Large databases of clinician reported (e.g., allergy repositories) and patient reported (e.g., social media) adverse drug reactions (ADRs) exist; however, whether patients and clinicians report the same concerns is not clear.

OBJECTIVES

Our objective was to compare electronic health record data and social media data to better understand differences and similarities between clinician-reported ADRs and patients' concerns regarding aspirin and atorvastatin.

METHODS

This pilot study explored a large repository of electronic health record data and social media data for clinician-reported ADRs and patients concerns for two common medications: aspirin (n = 31,817 ADRs accessible in clinical data; n = 19,186 potential ADRs accessible in social media data) and atorvastatin (n = 15,047 ADRs accessible in clinical data; n = 23,408 potential ADRs accessible in social media data).

RESULTS

We found that the most frequently reported ADRs matched the most frequent patients' concerns. However, several less frequently reported reactions were more prevalent on social media (i.e., aspirin-induced hypoglycemia was discussed only on social media). Overall, we found a relatively strong positive and statistically significant correlation between the frequency ranking of reactions and patients' concerns for atorvastatin (Pearson's r = 0.61, p < 0.001) but not for aspirin (Pearson's r = 0.1, p = 0.69).

CONCLUSION

Future studies should develop further natural language methods for a more detailed data analysis (i.e., identifying causality and temporal aspects in the social media data).

Adverse clinical outcomes associated with a low dose and a high dose of aspirin following percutaneous coronary intervention: a systematic review and meta-analysis

Background

Guidelines from the American Heart Association/American College of Cardiology recommend a higher dosage of aspirin daily following Percutaneous Coronary Intervention (PCI), whereas guidelines from the European Society of Cardiology recommend a lower dosage. This study aimed to compare the adverse clinical outcomes associated with a low dose and a high dose of aspirin following PCI.

Methods

Electronic databases were searched for studies comparing a low dose with a high dose aspirin following PCI. Adverse clinical outcomes were considered as the endpoints in this study. We calculated Odds Ratios (OR) with 95 % Confidence Intervals (CIs) for categorical variables. The pooled analyses were performed with RevMan 5.3 software.

Results

A total number of 25,083 patients were included. Results from this analysis showed that the combination of Cardiovascular (CV) death/Myocardial Infarction (MI) or stroke was not significantly different between a low and high dose of aspirin with OR: 1.08, 95 % CI: 0.98–1.18; P = 0.11. Mortality and MI were also not significantly different between these two treatment regimens following PCI with OR: 0.95, 95 % CI: 0.74–1.23; P = 0.71 and OR: 1.17, 95 % CI: 0.97–1.41; P = 0.09 respectively. However, a high dose of aspirin was associated with a significantly higher rate of Major Adverse Cardiac Events (MACEs) with OR: 1.20, 95 % CI: 1.02–1.41; P = 0.03. Thrombolysis In Myocardial Infarction (TIMI) defined minor bleeding was also significantly higher with a high dose aspirin with OR: 1.22, 95 % CI: 1.02–1.47; P = 0.03. When Stent thrombosis (ST) was compared, no significant difference was found with OR: 1.28, 95 % CI: 0.59–2.58; P = 0.53. Even if TIMI defined major bleeding favored a low dose of aspirin, with OR: 1.42, 95 % CI: 0.95–2.13; P = 0.09, or even if major bleeding was insignificantly higher with a high dose aspirin, with OR: 1.78, 95 % CI: 1.01–3.13; P = 0.05; I² = 94 %, higher levels of heterogeneity observed in these subgroups could not be considered significant to any extent.

Conclusion

According to the results of this analysis, a high dose of aspirin following PCI was not associated with any significantly higher rate of CV death/MI/stroke, mortality or MI. However, MACEs significantly favored a low dose of aspirin. In addition, TIMI defined minor bleeding was significantly higher with a high dose of aspirin whereas the results for the major bleeding outcomes were not statistically significant. However, due to limited data availability and since the subgroups analyzing major bleeding were highly heterogeneous, further studies are recommended to completely solve this issue.

Anti-platelet drugs attenuate the expansion of circulating CD14highCD16+ monocytes under pro-inflammatory conditions

Aims

Levels of circulating CD14^highCD16⁺ monocytes increase in atherosclerotic patients and are predictive of future cardiovascular events. Platelet activation has been identified as a crucial determinant in the acquisition of a CD16⁺ phenotype by classical CD14^highCD16⁻ cells. We tested the hypothesis that anti-platelet drugs modulate the phenotype of circulating monocytes.

Methods and results

Sixty healthy subjects undergoing influenza immunization were randomly assigned to either no treatment or anti-platelet therapy, namely aspirin 300 mg or 75 mg daily, or clopidogrel (300 mg loading dose followed by 75 mg), for 48 h post-immunization (n = 15/group). Monocyte subsets, high-sensitivity C-reactive protein, pro-inflammatory cytokines, and P-selectin were measured at baseline and post-immunization. The CD14^highCD16⁺ monocyte cell count rose by 67.3% [interquartile range (IQR): 35.7/169.2; P = 0.0002 vs. baseline] in untreated participants. All anti-platelet regimes counteracted expansion of this monocytic subpopulation. Although no statistical differences were noted among the three treatments, aspirin 300 mg was the most efficacious compared with the untreated group (−12.5% change from baseline; IQR: −28.7/18.31; P = 0.001 vs. untreated). Similarly, the rise in P-selectin (17%; IQR: −5.0/39.7; P = 0.03 vs. baseline) observed in untreated participants was abolished by all treatments, with aspirin 300 mg exerting the strongest effect (−30.7%; IQR: −58.4/−0.03; P = 0.007 vs. untreated). Changes in P-selectin levels directly correlated with changes in CD14^highCD16⁺ cell count (r = 0.5; P = 0.0002). There was a similar increase among groups in high-sensitivity C-reactive protein (P < 0.03 vs. baseline levels).

Conclusions

Anti-platelet drugs exert an immunomodulatory action by counteracting CD14^highCD16⁺ monocyte increase under pro-inflammatory conditions, with this effect being dependent on the amplitude of P-selectin reduction.

Clopidogrel Use as Single Antiplatelet Therapy in Outpatients with Stable Coronary Artery Disease: Prevalence, Correlates and Association with Prognosis (from the CORONOR Study)

Background: Clopidogrel use as single antiplatelet therapy (SAPT) has never been evaluated in stable coronary artery disease (CAD) outpatients either as compared to placebo or aspirin. Methods: We therefore studied 2,823 outpatients included in a prospective registry. The patients were divided into 2 groups according to their antiplatelet therapy regimen: patients treated with clopidogrel were compared with those treated with aspirin alone. Results: The mean time since CAD diagnosis was 7.9 years. Altogether, 776 (27.5%) patients received clopidogrel as SAPT. Factors independently associated with clopidogrel use were prior aortic or peripheral intervention, drug-eluting stent implantation, stroke, carotid endarterectomy and time since CAD diagnosis. Clopidogrel tended to be used in higher-risk patients: composite of cardiovascular death, myocardial infarction or stroke at 5.8 versus 4.2% (p = 0.056). However, after propensity score matching, similar event rates were observed between the groups: 5.9% when treated with clopidogrel versus 4.4% with aspirin (p = 0.207). The rate of bleeding was also similar between the groups. Conclusions: Our study shows that a significant proportion of stable CAD patients are treated with clopidogrel as SAPT in modern practice. Several correlates of such an attitude were identified. Our results suggest that this strategy is not beneficial as compared to aspirin alone in terms of ischaemic or bleeding events.

Association of Discharge Aspirin Dose With Outcomes After Acute Myocardial Infarction

Background—

Aspirin is the most widely used antiplatelet drug postmyocardial infarction, yet its optimal maintenance dose after percutaneous coronary intervention with stenting remains uncertain.

Methods and Results—

We compared outcomes of 10 213 patients with myocardial infarction who underwent percutaneous coronary intervention and were discharged on dual-antiplatelet therapy at 228 US hospitals in the Treatment with ADP Receptor Inhibitors: Longitudinal Assessment of Treatment Patterns and Events after Acute Coronary Syndrome (TRANSLATE-ACS) study from 2010 to 2012. Major adverse cardiovascular events and bleeding within 6 months postdischarge were compared between high-dose (325 mg) and low-dose aspirin (81 mg) by using regression models with inverse probability-weighted propensity adjustment. Overall, 6387 patients (63%) received high-dose aspirin at discharge. Major adverse cardiovascular events risk was not significantly different between groups (high versus low: unadjusted 8.2% versus 9.2%; adjusted hazard ratio, 0.99; 95% confidence interval, 0.85–1.17). High-dose aspirin use was associated with greater risk of any Bleeding Academic Research Consortium–defined bleeding events (unadjusted 24.2% versus 22.7%; adjusted odds ratio, 1.19; 95% confidence interval, 1.06–1.33), driven mostly by minor Bleeding Academic Research Consortium type 1 or 2 bleeding events not requiring hospitalization (unadjusted 21.4% versus 19.5%; adjusted odds ratio, 1.19; 95% confidence interval, 1.05–1.34). Bleeding events requiring hospitalization were similar by aspirin dosing groups (unadjusted 2.8% versus 3.2%, adjusted odds ratio, 1.22; 95% confidence interval, 0.87–1.70). Similar associations were observed in landmark analyses accounting for aspirin dosing change over time, and across subgroup analyses by age, sex, baseline aspirin use, and type of ADP receptor inhibitor (clopidogrel versus prasugrel/ticagrelor).

Conclusions—

Among percutaneous coronary intervention–treated patients with myocardial infarction, high-maintenance-dose aspirin was associated with similar rates of major adverse cardiovascular events, but a greater risk of minor bleeding than those discharged on low-dose 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.

ST elevation myocardial infarction: recent advances and updates

ST elevation myocardial infarction (STEMI) remains a leading cause of morbidity, mortality and disability worldwide. Statistically, a trend towards improvements in morbidity and mortality has been consistent over the years, which is attributed primarily to the modification of risk factors, healthier lifestyles, treatment advances and better management of door-to-balloon times via STEMI systems. However, a major challenge in the coming years will be the baby boomers (born between the years 1946 and 1964) coming into old age. The first baby boomers turned 65 in year 2011. As the baby boomers age in the coming years, the incidence of coronary heart disease is likely to increase, and so there will be a greater need to have major advances in the management of coronary heart disease in order to deal with this additional incidence. The scope of this article is to review recent advances in the management of STEMI and to provide an updated overview.

PA32540 for the secondary prevention of cardiovascular disease in patients at risk for aspirin-associated gastric ulcers

Prescribed in patients with a history of myocardial infarction, stroke, transient ischemic attack, coronary intervention or bypass surgery, aspirin is one of the medications most commonly used in the secondary prevention of cardiovascular diseases. It has become a mainstay of therapy after years of solid evidence supporting its efficacy in clinical trials. However, a number of risks and side effects accompany its benefits, including the notable risk of bleeding and gastrointestinal side effects. Numerous mechanisms have been proposed to attenuate these effects to promote adherence and to expand the population for which aspirin is a reasonable treatment option. A polypill or combination formulation that includes a proton pump inhibitor, a drug commonly prescribed alongside aspirin, is one potential avenue of therapy. One such combination pill, PA32540, has undergone Phase I and Phase III trials and shows promising safety and efficacy results in these preliminary trials.

Frequency of the use of low- versus high-dose aspirin in dual antiplatelet therapy after percutaneous coronary intervention (from the Dual Antiplatelet Therapy study)

In randomized trials, low-dose (LD) and high-dose (HD) aspirin (ASA) are equally effective in reducing ischemic complications, but HD ASA is associated with an increased risk of bleeding in the setting of dual antiplatelet therapy after percutaneous coronary intervention (PCI). ASA dose after PCI varies across countries, but little is known about variation within the United States (US) and whether this variation can be explained by clinical characteristics of patients. We used enrollment data from the Dual Antiplatelet Therapy Study, a randomized trial designed to compare 12 versus 30 months of dual antiplatelet therapy after PCI, to quantify the variation in ASA dosing after PCI in the US subjects and assess the extent to which dose variability was attributable to patient characteristics. Of the 23,336 patients enrolled in the US, 28.0% were prescribed LD ASA at discharge after PCI. Patient characteristics explained 1.6% of total variance in ASA dose, whereas the study site accounted for 45.9% of the unexplained variability. The median odds ratio comparing sites was 5.05 (95% confidence interval 4.29 to 5.85), which was greater than any individual predictor of ASA dose. In conclusion, LD ASA after PCI in the US was used in a minority of patients, and heterogeneity in its selection was mainly influenced by the site of enrollment rather than patient characteristics. As HD ASA may be associated with adverse events in the setting of dual antiplatelet therapy, reducing local practice variation in the dose of ASA may be a target for quality improvement.

Therapy in ST-elevation myocardial infarction: reperfusion strategies, pharmacology and stent selection

OPINION STATEMENT

The estimated annual incidence of new and recurrent myocardial infarction (MI) in the U.S. is 715,000 events. Primary percutaneous coronary intervention (PCI) is the reperfusion strategy of choice in most patients with acute ST-elevation myocardial infarction (STEMI). Recent advances in percutaneous techniques and devices, including manual aspiration catheters and newer generation drug eluting stents and pharmacologic therapies, such as novel antiplatelets and anticoagulants have led to significant improvements in the acute and long-term outcomes for these patients. Implementation of community-wide systems directed to shorten treatment times tied to closely monitored quality improvement processes have led to further advances in STEMI care. Recent data suggests that transradial access for primary PCI is associated with improved outcomes. This contemporary review discusses the strategies for reperfusion, pharmacological therapy and stent selection process involved in STEMI.

Optimal aspirin dose in acute coronary syndromes: an emerging consensus

ABSTRACT: 

Numerous clinical trials testing the efficacy of aspirin for the secondary prevention of cardiovascular disease have been published. We reviewed the literature pertaining to aspirin dose in acute coronary syndrome patients. Clinical trials assessing the comparative efficacy of different doses of aspirin are scarce. This complex antiplatelet therapy landscape makes it difficult to identify the best aspirin dose for optimizing efficacy and minimizing risk of adverse events, while complying with the various guidelines and recommendations. Despite this fact, current evidence suggests that aspirin doses of 75–100 mg/day may offer the optimal benefit:risk ratio in acute coronary syndrome patients.

Perioperative management of antiplatelet therapy

Worldwide, cardiovascular events represent the major cause of morbidity and mortality. A key role in the pathogenesis of these events is played by platelets. Interventional procedures, with placement of coronary and vascular stents, often represent the preferred therapeutic strategy. Antiplatelet medications are considered first-line therapy in preventing cardiovascular thrombotic events. A wide array of antiplatelet agents is available, each with different pharmacological properties. When patients on antiplatelet agents present for surgery, the perioperative team must design an optimal strategy to manage antiplatelet medications. Each patient is stratified according to risk of developing a cardiovascular thrombotic event and inherent risk of surgical bleeding. After risk stratification analysis, various therapeutic pathways include continuing or discontinuing all antiplatelet agents or maintaining one antiplatelet agent and discontinuing the other. This review focuses on the pharmacological and pharmacokinetic properties of both older and novel antiplatelet drugs, and reviews current literature and guidelines addressing options for perioperative antiplatelet management.