Prolonged antithrombotic therapy in patients after acute coronary syndrome: A critical appraisal of current European Society of Cardiology guidelines

Balancing Benefits and Risks of Oral Antiplatelet Strategies in patients With Coronary Artery Diseases: An Evolving Issue

Identifying the most appropriate antiplatelet therapy for each patient to prevent ischemic events while minimizing the risk of bleeding is an integral part of the short- and long-term management of patients with coronary artery disease (CAD). This review aims to summarize the available evidence on the contemporary use of P2Y12 inhibitors in CAD patients, focusing on strategies aimed at providing adequate ischemic protection while preventing bleeding risk through dual antiplatelet therapy (DAPT) modulation. Randomized trials and observational studies have been reviewed to determine the most appropriate antiplatelet treatment for CAD patients with different risk profiles. Both ischemic and bleeding events have a significant prognostic impact and should be carefully considered in clinical decision-making. Current guidelines recommend the use of third-generation PY2Y12 inhibitors (prasugrel or ticagrelor) over clopidogrel, as a part of DAPT, in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention. Newer P2Y12 inhibitors have a more rapid onset of action and less interindividual variability in platelet inhibition than clopidogrel but are associated with an increased risk of bleeding that may limit their benefit. Importantly, the anti-ischemic benefit of ticagrelor and prasugrel is mainly observed in the first weeks after ACS, whereas clopidogrel seems to provide the best balance between ischemic protection and bleeding as long-term maintenance therapy. These concepts support DAPT modulation after the acute phase, by de-escalating from full-dose to low-dose newer P2Y12 inhibitors, by switching to clopidogrel, or by early withdrawing aspirin to maximize both the efficacy and safety of antiplatelet therapy in patients with CAD.

Optimization of the pharmacological therapy in patients with poly-vascular disease: A multidisciplinary approach

The recent shift of the concept of cardiovascular disease as a chronic progressive condition, potentially involving multiple districts, has driven attention to the optimal management of patients with concomitant coronary and peripheral artery disease, representing a subset of patients with an increased risk of events and impaired survival. Recent pharmacological achievements in terms of antithrombotic therapy and lipid-lowering drugs allow multiple therapeutical combinations, thus requiring optimizing the treatment in a tailored fashion according to patients’ risk profiles. Nevertheless, data dedicated to this specific subset of patients are still modest. We summarize currently available strategies and indications for the management of antithrombotic and lipid-lowering drugs in patients with the poly-vascular disease.

Acute coronary syndromes in diabetic patients, outcome, revascularization, and antithrombotic therapy

Diabetes exacerbates the progression of atherosclerosis and is associated with increased risk of developing acute coronary syndrome (ACS). Approximatively 25-30% of patients admitted for ACS have diabetes. ACS occurs earlier in diabetics and is associated with increased mortality and a higher risk of recurrent ischemic events. An increased proinflammatory and prothrombotic state is involved in the poorer outcomes of diabetic patients. In the past decade advancement in both percutaneous coronary intervention (PCI) and coronary artery by-pass graft (CABG) techniques and more potent antiplatelet drugs like prasugrel and ticagrelor improved outcomes of diabetic patients with ACS, but this population still experiences worse outcomes compared to non-diabetic patients. While in ST elevation myocardial infarction urgent PCI is the method of choice for revascularization, in patients with non-ST elevation ACS an early invasive approach is suggested by the guidelines, but in the setting of multivessel (MV) or complex coronary artery disease (CAD) the revascularization strategy is less clear. This review describes the accumulating evidence regarding factors involved in promoting increased incidence and poor prognosis of ACS in patients with diabetes, the evolution over time of prognosis and outcomes, revascularization strategies and antithrombotic therapy studied until now.

A new approach to ticagrelor-based de-escalation of antiplatelet therapy after acute coronary syndrome. A rationale for a randomized, double-blind, placebo-controlled, investigator-initiated, multicenter clinical study

The risk of ischemic events gradually decreases after acute coronary syndrome (ACS), reaching a stable level after 1 month, while the risk of bleeding remains steady during the whole period of dual antiplatelet treatment (DAPT). Several de-escalation strategies of antiplatelet treatment aiming to enhance safety of DAPT without depriving it of its efficacy have been evaluated so far. We hypothesized that reduction of the ticagrelor maintenance dose 1 month after ACS and its continuation until 12 months after ACS may improve adherence to antiplatelet treatment due to better tolerability compared with the standard dose of ticagrelor. Moreover, improved safety of treatment and preserved anti-ischemic benefit may also be expected with additional acetylsalicylic acid (ASA) withdrawal. To evaluate these hypotheses, we designed the Evaluating Safety and Efficacy of Two Ticagrelor-based De-escalation Antiplatelet Strategies in Acute Coronary Syndrome - a randomized clinical trial (ELECTRA-SIRIO 2), to assess the influence of ticagrelor dose reduction with or without continuation of ASA versus DAPT with standard dose ticagrelor in reducing clinically relevant bleeding and maintaining anti-ischemic efficacy in ACS patients. The study was designed as a phase III, randomized, multicenter, double-blind, investigator-initiated clinical study with a 12-month follow-up (ClinicalTrials.gov Identifier: NCT04718025; EudraCT number: 2020-005130-15).

Therapy Discontinuation after Myocardial Infarction

The discontinuation of recommended therapy after myocardial infarction predisposes patients to serious thrombotic complications. The aim of this study was a comprehensive analysis of permanent as well as short- and long-term discontinuation of pharmacotherapy, taking into consideration the basic groups of medications and nonadherence determinants in a one-year follow-up in post-myocardial infarction (MI) patients.

MATERIAL AND METHODS

The study was a single center cohort clinical trial with a one-year follow-up including 225 patients (73.3% men, 26.7% women) aged 62.9 ± 11.9 years. In eight cases (3.6%), the follow-up duration was less than one year due to premature death. The following factors were analyzed: lack of post-discharge therapy initiation; short-term therapy discontinuation (<30 days); long-term therapy discontinuation (≥30 days); and permanent cessation of therapy. The analysis of therapy discontinuation was performed based on prescription filling data.

RESULTS

Occupational activity (Odds Ratio (OR) 5.15; 95% Confidence interval (CI) 1.42-18.65; p = 0.013) and prior MI (OR 5.02; 95% CI 1.45-16.89; p = 0.009) were found to be independent predictors of a lack of post-discharge therapy initiation with P2Y12 receptor inhibitors. We found no independent predictors of lack of post-discharge therapy initiation with other medications, whether analyzed separately or together. Age above 65 years (Hazard Ratio (HR)-1.59; 95% CI 1.15-2.19; p = 0.0049) and prior revascularization (HR-1.44; 95% CI 1.04-2.19; p = 0.0273) were identified as independent predictors of therapy discontinuation. Multilogistic regression analysis showed no independent predictors of the cessation of any of the medications as well as the permanent or temporary simultaneous discontinuation of all medications.

CONCLUSIONS

The vast majority of post-MI patients discontinue, either temporarily or permanently, one of the essential medications within one year following myocardial infarction. The most likely medication class to be discontinued are statins. Older age and prior cardiac revascularization are independent determinants of therapy discontinuation.