Tailoring oral antiplatelet therapy in acute coronary syndromes: from guidelines to clinical practice

Negative selection bias for women inclusion in a clinical trial

INTRODUCTION

Despite the growing awareness towards the importance of adequate representation of women in clinical trials among patients treated with percutaneous coronary intervention (PCI), available evidence continues to demonstrate a skewed distribution of study populations in favour of men.

METHODS AND RESULTS

In this pre-specified analysis from the MASTER DAPT screening log and trial, we aimed to investigate the existence of a negative selection bias for women inclusion in a randomized clinical trial. A total of 2847 consecutive patients who underwent coronary revascularization across 65 participating sites, during a median of 14 days, were entered in the screening log, including 1749 (61.4%) non-high bleeding risk (HBR) and 1098 (38.6%) HBR patients, of whom 109 (9.9%) consented for trial participation. Female patients were less represented in consented versus non-consented HBR patients (22% versus 30%, absolute standardized difference: 0.18) and among non-consented eligible versus consented eligible patients (absolute standardized difference 0.14). The observed sex gap was primarily due investigators' choice not to offer study participation to females because deemed at very high risk of bleeding and/or ischemic complications, and only marginally to a slightly higher propensity of females compared to males to refuse study participation.

CONCLUSIONS

Female HBR patients undergoing PCI are less prevalent, but also less likely to participate in the trial than male patients, mainly due to investigators' preference.

Consecutive or selectively included high bleeding risk patients in the MASTER DAPT screening log and trial

AIMS

Screening logs have the potential to appraise the actual prevalence and distribution of predefined patient subsets, avoiding selection biases, which are inevitably and potentially present in randomised trials and real-world registries, respectively. We aimed to assess the prevalence of high bleeding risk (HBR) characteristics in the real world and the external validity of the MASTER DAPT trial.

METHODS AND RESULTS

All consecutive patients who underwent percutaneous coronary intervention (PCI) for at least two consecutive weeks across 65 sites participating in the trial were entered into a screening log. Of 2,847 consecutive patients, 1,098 (38.6 %) were HBR and 109 (9.9 %) consented for trial participation. PRECISE-DAPT score ≥ 25 was the most frequent HBR feature, followed by advanced age, use of oral anticoagulation (OAC) and anaemia. Compared with consecutive HBR patients, consenting patients were older (≥ 75 years: 69 % versus 62 %, absolute standardized difference [SD] 0.16), more frequently male (78 % versus 71 %, absolute SD 0.18), had higher use of OAC (38 % versus 20 %, absolute SD 0.39), treatment with steroids or nonsteroidal anti-inflammatory drugs (10 % versus 5 %, SD 0.16), and prior cerebrovascular events (10 % versus 6 %, absolute SD 0.18) but lower PRECISE DAPT score ≥ 25 (54 % versus 66 %, absolute SD 0.24).

CONCLUSIONS

The HBR criteria distribution differed between consecutive versus selectively included HBR patients, suggesting the existence of selection biases in the trial population.

Demystifying the Contemporary Role of 12-Month Dual Antiplatelet Therapy After Acute Coronary Syndrome

For almost two decades, 12-month dual antiplatelet therapy (DAPT) in acute coronary syndrome (ACS) has been the only class I recommendation on DAPT in American and European guidelines, which has resulted in 12-month durations of DAPT therapy being the most frequently implemented in ACS patients undergoing percutaneous coronary intervention (PCI) across the globe. Twelve-month DAPT was initially grounded in the results of the CURE (Clopidogrel in Unstable Angina to Prevent Recurrent Events) trial, which, by design, studied DAPT versus no DAPT rather than the optimal DAPT duration. The average DAPT duration in this study was 9 months, not 12 months. Subsequent ACS studies, which were not designed to assess DAPT duration, rather its composition (aspirin with prasugrel or ticagrelor compared with clopidogrel) were further interpreted as supportive evidence for 12-month DAPT duration. In these studies, the median DAPT duration was 9 or 15 months for ticagrelor and prasugrel, respectively. Several subsequent studies questioned the 12-month regimen and suggested that DAPT duration should either be fewer than 12 months in patients at high bleeding risk or more than 12 months in patients at high ischemic risk who can safely tolerate the treatment. Bleeding, rather than ischemic risk assessment, has emerged as a treatment modifier for maximizing the net clinical benefit of DAPT, due to excessive bleeding and no clear benefit of prolonged treatment regimens in high bleeding risk patients. Multiple DAPT de-escalation treatment strategies, including switching from prasugrel or ticagrelor to clopidogrel, reducing the dose of prasugrel or ticagrelor, and shortening DAPT duration while maintaining monotherapy with ticagrelor, have been consistently shown to reduce bleeding without increasing fatal or nonfatal cardiovascular or cerebral ischemic risks compared with 12-month DAPT. However, 12-month DAPT remains the only class-I DAPT recommendation for patients with ACS despite the lack of prospectively established evidence, leading to unnecessary and potentially harmful overtreatment in many patients. It is time for clinical practice and guideline recommendations to be updated to reflect the totality of the evidence regarding the optimal DAPT duration in ACS.

Antithrombotic therapy in patients with acute coronary syndrome: similarities and differences between a European expert consensus document and the 2023 European Society of Cardiology guidelines

Antithrombotic therapy represents the cornerstone of the pharmacological treatment in patients with acute coronary syndrome (ACS). The optimal combination and duration of antithrombotic therapy is still matter of debate requiring a critical assessment of patient comorbidities, clinical presentation, revascularization modality, and/or optimization of medical treatment. The 2023 European Society of Cardiology (ESC) guidelines for the management of patients with ACS encompassing both patients with and without ST segment elevation ACS have been recently published. Shortly before, a European expert consensus task force produced guidance for clinicians on the management of antithrombotic therapy in patients with ACS as well as chronic coronary syndrome. The scope of this manuscript is to provide a critical appraisal of differences and similarities between the European consensus paper and the latest ESC recommendations on oral antithrombotic regimens in ACS patients.

Platelets and the Atherosclerotic Process: An Overview of New Markers of Platelet Activation and Reactivity, and Their Implications in Primary and Secondary Prevention

The key role played by platelets in the atherosclerosis physiopathology, especially in the acute setting, is ascertained: they are the main actors during thrombus formation and, thus, one of the major investigated elements related to atherothrombotic process involving coronary arteries. Platelets have been studied from different points of view, according with the technology advances and the improvement in the hemostasis knowledge achieved in the last years. Morphology and reactivity constitute the first aspects investigated related to platelets with a significant body of evidence published linking a number of their values and markers to coronary artery disease and cardiovascular events. Recently, the impact of genetics on platelet activation has been explored with promising findings as additional instrument for patient risk stratification; however, this deserves further confirmations. Moreover, the interplay between immune system and platelets has been partially elucidated in the last years, providing intriguing elements that will be basic components for future research to better understand platelet regulation and improve cardiovascular outcome of patients.

Comparative analysis of level of evidence and class of recommendation for 50 clinical practice guidelines released by the European Society of Cardiology from 2011 to 2022

BACKGROUND

The European Society of Cardiology (ESC) clinical practice guidelines are essential tools for decision-making.

AIM

To analyze the level of evidence (LOE) and the class of recommendations in the ESC guidelines released in the last 12 years.

METHODS

We evaluated 50 ESC guidelines released from 2011 to 2022, related to 27 topics and categorized them into seven macro-groups. We analyzed every recommendation in terms of LOE and class of recommendation, calculating their relative proportions and changes over time in consecutive editions of the same guideline.

RESULTS

A total of 6972 recommendations were found, with an increase in number per year over time. Among the 50 ESC guidelines, the proportional distribution of classes of recommendations was 49% for Class I, 29% for Class IIa, 15% for Class IIb, and 8% for Class III. Overall, 16% of the recommendations were classified as LOE A, 31% LOE B and 53% LOE C. The field of preventive cardiology had the largest proportion of LOE A, while the lowest was in the field of valvular, myocardial, pericardial and pulmonary diseases. The overall proportion of LOE A recommendations in the most recent guidelines compared to their prior versions increased from 17% to 20%.

CONCLUSIONS

The recommendations included in the ESC guidelines widely differ in terms of quality of evidence, with only 16% supported by the highest quality of evidence. Although a slight global increase in LOE A recommendations was observed in recent years, further scientific research efforts are needed to increase the quality of evidence.

Antiplatelet Strategies for Older Patients with Acute Coronary Syndromes: Finding Directions in a Low-Evidence Field

Patients ≥ 75 years of age account for about one third of hospitalizations for acute coronary syndromes (ACS). Since the latest European Society of Cardiology guidelines recommend that older ACS patients use the same diagnostic and interventional strategies used by the younger ones, most elderly patients are currently treated invasively. Therefore, an appropriate dual antiplatelet therapy (DAPT) is indicated as part of the secondary prevention strategy to be implemented in such patients. The choice of the composition and duration of DAPT should be tailored on an individual basis, after careful assessment of the thrombotic and bleeding risk of each patient. Advanced age is a main risk factor for bleeding. Recent data show that in patients of high bleeding risk short DAPT (1 to 3 months) is associated with decreased bleeding complications and similar thrombotic events, as compared to standard 12-month DAPT. Clopidogrel seems the preferable P2Y12 inhibitor, due to a better safety profile than ticagrelor. When the bleeding risk is associated with a high thrombotic risk (a circumstance present in about two thirds of older ACS patients) it is important to tailor the treatment by taking into account the fact that the thrombotic risk is high during the first months after the index event and then wanes gradually over time, whereas the bleeding risk remains constant. Under these circumstances, a de-escalation strategy seems reasonable, starting with DAPT that includes aspirin and low-dose prasugrel (a more potent and reliable P2Y12 inhibitor than clopidogrel) then switching after 2-3 months to DAPT with aspirin and clopidogrel for up to 12 months.