Impact of Intravenous Lysine Acetylsalicylate Versus Oral Aspirin on Prasugrel-Inhibited Platelets

Effects of intravenous lysine acetylsalicylate versus oral aspirin on platelet responsiveness in patients with ST-segment elevation myocardial infarction: the ECCLIPSE-STEMI trial

Prasugrel and ticagrelor, new P2Y12-ADP receptor antagonists, are associated with greater pharmacodynamic inhibition and reduction of cardiovascular events in patients with an acute coronary syndrome. However, evidence is lacked about the effects of achieving faster and stronger cyclooxygenase inhibition with intravenous lysine acetylsalicylate (LA) compared to oral aspirin. Recently, we demonstrated in healthy volunteers that the administration of intravenous LA resulted in a significantly reduction of platelet reactivity compared to oral aspirin. Loading dose of LA achieves platelet inhibition faster, and with less variability than aspirin. However, there are no data of this issue in patients with an ST-segment elevation myocardial infarction (STEMI). This is a prospective, randomized, multicenter, open platelet function study conducted in STEMI patients. Subjects were randomly assigned to receive a loading dose (LD) of intravenous LA 450 mg plus oral ticagrelor 180 mg, or LD of aspirin 300 mg plus ticagrelor 180 mg orally. Platelet function was evaluated at baseline, 30 min, 1 h, 4 h and 24 h using multiple electrode aggregometry and vasodilator-stimulated phosphoprotein phosphorylation (VASP). The primary endpoint of the study is the inhibition of platelet aggregation (IPA) after arachidonic acid (AA) 0.5 mM at 30 min. Secondary endpoints were the IPA at 1, 4, and 24 h after AA, and non-AA pathways through the sequence (ADP and TRAP). A total of 32 STEMI patients were randomized (16 LA, 16 aspirin). The inhibition of platelet aggregation after AA 0.5 mM at 30 min was greater in subjects treated with LA compared with aspirin: 166 vs. 412 respectively (p = 0.001). This differential effect was observed at 1 h (p = 0.01), but not at 4 and 24 h. Subjects treated with LA presented less variability and faster inhibition of platelet aggregation wit AA compared with aspirin. The administration of intravenous LA resulted in a significantly reduction of platelet reactivity compared to oral aspirin on ticagrelor inhibited platelets in patients with STEMI. Loading dose of LA achieves an earlier platelet inhibition, and with less variability than aspirin.Trial Registration: Unique identifier: NCT02929888; URL: http://www.clinicaltrials.gov.

Acetylsalicylic Acid-Primus Inter Pares in Pharmacology

Acetylsalicylic acid (ASA) is one of the first drugs to be obtained by synthesis while being the most used. It has experienced the longest lasting commercial success and is considered the most popular drug of the modern era. ASA, originally used as an anti-inflammatory medication, nowadays is predominantly used as an antiplatelet agent for prophylaxis in cardiac patients. Many studies show that the benefits of using ASA far outweigh the potential risk of side effects. With particular emphasis on the possibility of ASA repositioning for new therapies, extending the indications for use beyond the diseases from the spectrum of atherosclerotic diseases, such as cancer, requires shifting the benefit-risk ratio, although very good, even more towards safety. Interesting activities consisting not only of changing the formulation but also modifying the drug molecule seem to be an important goal of the 21st century. ASA has become a milestone in two important fields: pharmacy and medicine. For a pharmacist, ASA is a long-used drug for which individual indications are practically maintained. For a doctor, acetylsalicylic acid is primarily an antiplatelet drug that saves millions of lives of patients with coronary heart disease or after a stroke. These facts do not exempt us from improving therapeutic methods based on ASA, the main goal of which is to reduce the risk of side effects, as well as to extend effectiveness. Modified acetylsalicylic acid molecules already seem to be a promising therapeutic option.

Antiplatelet Therapy for Atherothrombotic Disease in 2022—From Population to Patient-Centered Approaches

Antiplatelet agents, with aspirin and P2Y₁₂ receptor antagonists as major key molecules, are currently the cornerstone of pharmacological treatment of atherothrombotic events including a variety of cardio- and cerebro-vascular as well as peripheral artery diseases. Over the last decades, significant changes have been made to antiplatelet therapeutic and prophylactic strategies. The shift from a population-based approach to patient-centered precision medicine requires greater awareness of individual risks and benefits associated with the different antiplatelet strategies, so that the right patient gets the right therapy at the right time. In this review, we present the currently available antiplatelet agents, outline different management strategies, particularly in case of bleeding or in perioperative setting, and develop the concept of high on-treatment platelet reactivity and the steps toward person-centered precision medicine aiming to optimize patient care.

Flow modification on the internal carotid artery bifurcation region and A1 segment after M1-internal carotid artery flow diverter deployment

BACKGROUND

Clinical and hemodynamic consequences of flow diverters extending from the M1 to the internal carotid artery (ICA), covering the A1 segment, have rarely been investigated. We aimed to provide angiographic and clinical data about flow modifications on the covered A1.

METHODS

Consecutive patients receiving M1-ICA flow diverters for unruptured aneurysms were collected from our prospective database (2014-2020).

RESULTS

42 A1 arteries covered with a single device were studied. All patients had an angiographic detected contralateral flow from the anterior communicating artery (AcomA). Immediately after flow diversion, 20 (47.6%) covered A1 showed slow flow. During a mean angiographic follow-up of 14 months, 13 (31%) and 22 (52.3%) A1 arteries were occluded and narrowed, respectively. Flow changes were asymptomatic in all cases. Vascular risk factors, sex, oversized compared with not oversized stents, immediate A1 slow flow, age, diameter of the A1, length of follow-up, and platelet inhibition rate were tested as prognosticators of A1 occlusion. Length of the angiographic follow-up was the only predictor of A1 occlusion (p=0.005, OR=3, CI=1.4 to 6.7). There were two device related ischemic events with a 2.3% rate of morbidity (one basal ganglia infarct after coverage of the M1 perforators and one transient acute instent thrombosis).

CONCLUSIONS

Covering the A1 segment during M1-ICA flow diversion seems relatively safe, if the contralateral flow is assured by the AcomA. Approximately 31% and 52% of the covered A1 showed asymptomatic occlusions and narrowing, respectively. The likelihood of flow modification was proportional to the length of follow-up. Morbidity associated with flow diversion in the ICA terminus region was 2.3%.

Impaired aspirin-mediated platelet function inhibition in resuscitated patients with acute myocardial infarction treated with therapeutic hypothermia: a prospective, observational, non-randomized single-centre study

The majority of resuscitated patients present with underlying cardiac disease, and out of these myocardial infarction is most common. Immediate interventional treatment is recommended and routinely requires dual antiplatelet therapy including aspirin and a P2Y12-inhibitor. Therapeutic hypothermia or target temperature management is also recommended in these patients. Cardiogenic shock as well as reduced body temperature impacts platelet reactivity and its medical inhibition. The study aims to quantify aspirin- and P2Y12-mediated platelet inhibition in patients presenting with myocardial infarction and cardiopulmonary resuscitation. Twenty-five resuscitated patients were enrolled in this prospective, observational, non-randomized single-centre study. These patients were compared to 77 matched controls from the ATLANTIS-ACS database of non-resuscitated patients with myocardial infarction. Platelet function testing was performed by light transmittance aggregometry. Aspirin reactivity was monitored by inducing platelet aggregation with collagen and arachidonic acid, respectively. P2Y12 inhibition was recorded by stimulation of platelet aggregation with adenosine diphosphate. To quantify the overall platelet response, thrombin receptor-activated peptide was used. Aspirin-mediated platelet reactivity decreased significantly in resuscitated patients during the first days and was significantly weaker on day 3 (collagen AUC 253.8 (122.7–352.2) vs. 109.0 (73.0–182.0); p = 0.022). P2Y12-mediated platelet inhibition was also impaired in resuscitated patients on day 3 (mean ADP AUC (IQR): CPR 172.1 (46.7−346.5) vs. control 43.9 (18.9–115.2); p < 0.05). Aspirin- and P2Y12-mediated platelet inhibition is impaired in resuscitated patients treated with therapeutic hypothermia. On day 3, we recorded lowest inhibitory effects of both drug types and patients might be at particular risk at that time. Potentially, intravenous aspirin and P2Y12 inhibitors might still supply a more predictable and stable platelet inhibition.

Impaired biological response to aspirin in therapeutic hypothermia comatose patients resuscitated from out-of-hospital cardiac arrest

AIM OF THE STUDY

Acute coronary syndrome is one of the main causes of out-of-hospital cardiac arrest (OHCA). OHCA patients are particularly exposed to high platelet reactivity (HPR) under aspirin (ASA) treatment. The aim was to evaluate HPR-ASA in therapeutic hypothermia comatose patients resuscitated from OHCA.

METHODS AND RESULTS

Twenty-two consecutive patients with OHCA of cardiac origin were prospectively included after therapeutic hypothermia and randomized to receive ASA 100mg per day, either intravenously (n=13) or orally via a gastric tube (n=9). ADP inhibitors (prasugrel or, if contra-indicated, clopidogrel) were administered in the event of angioplasty. HPR-ASA was assessed by light transmission aggregometry (LTA) with arachidonic acid (AA) and by the PFA-100(®) system with collagen/epinephrine. Clinical, biological and angiographic characteristics were similar in both groups. Using LTA-AA, maximum aggregation intensity was significantly lower in the intravenous group compared to the oral group (15% vs. 29%, respectively; p=0.04). Overall, 10 patients (45%) had HPR-ASA (38% intravenously vs 56% orally; p=0.7). Similarly, closure time was significantly increased in the IV group (277s vs. 155s, respectively; p=0.04).

CONCLUSION

This study suggests that impaired response to both intravenous and oral aspirin is frequent in comatose patients resuscitated from OHCA.