The Effectiveness of Antiplatelet Therapy and the Factors Influencing It in Patients with Acute Coronary Syndrome before and during the COVID-19 Pandemic.

Background and Objectives: Dual antiplatelet therapy (DAPT) is essential in the treatment of patients with acute coronary syndrome (ACS). The objective of this study was to evaluate the effectiveness of antiplatelet medication in our practice and to investigate the factors that influence it. Materials and Methods: A prospective cohort observational study was conducted, in which 193 patients with ACS were enrolled. The patients were stented in the catheterization laboratory between May 2019 and October 2020, before and during the COVID-19 pandemic, and were receiving DAPT. Their platelet functions were tested using a Multiplate Analyzer. In addition to this, clinical data, demographics, laboratory tests, and cardiovascular risk factors were also analyzed. Results: 43.46% of the patients treated with aspirin were found to be resistant to it. This phenomenon was more common in men (48.17% vs. 31.48%, p = 0.036), and it was associated with being under the age of 50 (OR: 2.08; 95% CI: 1.11-3.90) and weighing over 70 kg (OR: 3.00; 95% CI: 1.21-7.40). Most of the patients treated with clopidogrel were in the optimal treatment window, while about half of the patients treated with ticagrelor had an exaggerated pharmacological response. Among the laboratory parameters, leukocytosis and platelet count were found to be determinants of platelet reactivity for both the aspirin and ticagrelor treatments. Conclusions: Many patients treated with antiplatelet agents are outside of the treatment window. The results obtained showed that low doses of gastro-resistant aspirin tablets are ineffective, and their efficacy can be influenced by various clinical and laboratory factors. Patients receiving ticagrelor have significantly reduced platelet reactivity, influenced only by certain laboratory indicators. The pandemic significantly influenced the results of the platelet aggregation tests only in patients treated with clopidogrel.

Anticoagulation and Antiplatelet Therapy for Prevention of Venous and Arterial Thrombotic Events in Critically Ill Patients With COVID-19: COVID-PACT.

BACKGROUND: The efficacy and safety of prophylactic full-dose anticoagulation and antiplatelet therapy in critically ill COVID-19 patients remain uncertain. METHODS: COVID-PACT (Prevention of Arteriovenous Thrombotic Events in Critically-ill COVID-19 Patients Trial) was a multicenter, 2×2 factorial, open-label, randomized-controlled trial with blinded end point adjudication in intensive care unit-level patients with COVID-19. Patients were randomly assigned to a strategy of full-dose anticoagulation or standard-dose prophylactic anticoagulation. Absent an indication for antiplatelet therapy, patients were additionally randomly assigned to either clopidogrel or no antiplatelet therapy. The primary efficacy outcome was the hierarchical composite of death attributable to venous or arterial thrombosis, pulmonary embolism, clinically evident deep venous thrombosis, type 1 myocardial infarction, ischemic stroke, systemic embolic event or acute limb ischemia, or clinically silent deep venous thrombosis, through hospital discharge or 28 days. The primary efficacy analyses included an unmatched win ratio and time-to-first event analysis while patients were on treatment. The primary safety outcome was fatal or life-threatening bleeding. The secondary safety outcome was moderate to severe bleeding. Recruitment was stopped early in March 2022 (≈50% planned recruitment) because of waning intensive care unit-level COVID-19 rates. RESULTS: At 34 centers in the United States, 390 patients were randomly assigned between anticoagulation strategies and 292 between antiplatelet strategies (382 and 290 in the on-treatment analyses). At randomization, 99% of patients required advanced respiratory therapy, including 15% requiring invasive mechanical ventilation; 40% required invasive ventilation during hospitalization. Comparing anticoagulation strategies, a greater proportion of wins occurred with full-dose anticoagulation (12.3%) versus standard-dose prophylactic anticoagulation (6.4%; win ratio, 1.95 [95% CI, 1.08-3.55]; P=0.028). Results were consistent in time-to-event analysis for the primary efficacy end point (full-dose versus standard-dose incidence 19/191 [9.9%] versus 29/191 [15.2%]; hazard ratio, 0.56 [95% CI, 0.32-0.99]; P=0.046). The primary safety end point occurred in 4 (2.1%) on full dose and in 1 (0.5%) on standard dose (P=0.19); the secondary safety end point occurred in 15 (7.9%) versus 1 (0.5%; P=0.002). There was no difference in all-cause mortality (hazard ratio, 0.91 [95% CI, 0.56-1.48]; P=0.70). There were no differences in the primary efficacy or safety end points with clopidogrel versus no antiplatelet therapy. CONCLUSIONS: In critically ill patients with COVID-19, full-dose anticoagulation, but not clopidogrel, reduced thrombotic complications with an increase in bleeding, driven primarily by transfusions in hemodynamically stable patients, and no apparent excess in mortality. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT04409834.

Thrombocytopathy vs Platelet hyper-reactivity in COVID-19: diverse pathologies, disease outcomes and therapeutic implications.

Coagulopathy is an evident complication of COVID-19 with predominance of a prothrombotic state. Platelet activation plays a key role. The terms "hyper-reactivity" and "hyperactivity" used in recent literature may not be clear or sufficient to explain the pathological events involved in COVID-related thrombosis (CRT). Inflammation may play a bigger role compared to thrombosis in COVID-related mortality because a smaller percentage of patients with COVID-19 die due to direct effects of thrombosis. Not all COVID-19 patients have thrombocytopenia and a few show thrombocytosis. We believe the platelet pathology is more complex than just activation or hyper-activation, particularly due to the platelets' role in inflammation. Understanding the pathology and consequences of platelets' role may help optimize management strategies and diminish CRT-associated morbidity and mortality. In this viewpoint report, we examine the published evidence of platelet hyper-reactivity in COVID-19 with a focused analysis of the key pathologies, diverse alterations, disease outcomes, and therapeutic targets. We believe that COVID-19 is a disease of inflammation and pathologic platelets, and based on the complexity and diverse pathologies, we propose the term "thrombocytopathy" as a more reflective term of the platelets' involvement in COVID-19. In our opinion, thrombocytopathy is the unpredictable pathologic alterations of platelets in function, morphology and number, caused by different factors with a variety of presentations.

Enhanced platelet inhibition treatment improves hypoxemia in patients with severe Covid-19 and hypercoagulability. A case control, proof of concept study.

Patients affected by severe coronavirus induced disease-2019 (Covid-19) often experience hypoxemia due to alveolar involvement and endothelial dysfunction, which leads to the formation of micro thrombi in the pulmonary capillary vessels. Both hypoxemia and a prothrombotic diathesis have been associated with more severe disease and increased risk of death. To date, specific indications to treat this condition are lacking. This was a single center, investigator initiated, compassionate use, proof of concept, case control, phase IIb study (NCT04368377) conducted in the Intermediate Respiratory Care Unit of L. Sacco University Hospital in Milano, Italy. Our objective was to explore the effects of the administration of anti-platelet therapy on arterial oxygenation and clinical outcomes in patients with severe Covid-19 with hypercoagulability. We enrolled five consecutive patients with laboratory confirmed SARS-CoV-2 infection, severe respiratory failure requiring helmet continuous positive airway pressure (CPAP), bilateral pulmonary infiltrates and a pro-thrombotic state identified as a D-dimer > 3 times the upper limit of normal. Five patients matched for age, D-dimer value and SOFA score formed the control group. Beyond standard of care, treated patients received 25 µg/Kg/body weight tirofiban as bolus infusion, followed by a continuous infusion of 0.15 µg/Kg/body weight per minute for 48 hours. Before tirofiban, patients received acetylsalicylic acid 250 mg infusion and oral clopidogrel 300 mg; both were continued at a dose of 75 mg daily for 30 days. Fondaparinux2.5 mg/day sub-cutaneous was given for the duration of the hospital stay. All controls were receiving prophylactic or therapeutic dose heparin, according to local standard operating procedures. Treated patients consistently experienced a mean (SD) reduction in A-a O2 gradient of -32.6 mmHg (61.9, P = 0.154), -52.4 mmHg (59.4, P = 0.016) and -151.1 mmHg (56.6, P = 0.011; P = 0.047 vs. controls) at 24, 48 hours and 7 days after treatment. PaO2/FiO2 ratio increased by 52 mmHg (50, P = 0.172), 64 mmHg (47, P = 0.040) and 112 mmHg (51, P = 0.036) after 24, 48 hours and 7 days, respectively. All patients but one were successfully weaned from CPAP after 3 days. This was not true for the control group. No major adverse events were observed. Antiplatelet therapy might be effective in improving the ventilation/perfusion ratio in Covid-19 patients with severe respiratory failure. The effects might be sustained by the prevention and interference on forming clots in lung capillary vessels and by modulating megakaryocytes' function and platelet adhesion. Randomized clinical trials are urgently needed to confirm these results.

Fibrinolysis is a reasonable alternative for STEMI care during the COVID-19 pandemic.

OBJECTIVE: No data are available to develop uniform recommendations for reperfusion therapies in ST-segment elevation myocardial infarction (STEMI) during the coronavirus disease 2019 (COVID-19) pandemic. We aimed to fill the evidence gap regarding STEMI reperfusion strategy during the COVID-19 era. METHODS: Clinical characteristics and outcomes for 17 patients with STEMI who received fibrinolysis during the COVID-19 pandemic were compared with 20 patients who received primary percutaneous coronary intervention (PPCI), and were further compared with another 41 patients who received PPCI in the pre-COVID-19 period. RESULTS: In patients with STEMI, fibrinolysis achieved a comparable in-hospital and 30-day primary composite end point, as compared with those who received PPCI during the COVID-19 pandemic. No major bleeding was detected in either group. Compared patients with STEMI who received PPCI in the pre-COVID-19 period, we found a remarkable extension of chest pain onset-to-first medical contact (FMC) and FMC-to-wire crossing times, significantly increased number and length of stents, and much worse thrombolysis in myocardial infarction flow in patients with STEMI who received PPCI during the COVID-19 pandemic. CONCLUSION: Owing to its considerable efficacy and safety and advantages in conserving medical resources, we recommend fibrinolysis as a reasonable alternative for STEMI care during the COVID-19 pandemic.

Rationale and design of the TAILOR-PCI digital study: Transitioning a randomized controlled trial to a digital registry.

BACKGROUND: Tailored Antiplatelet Initiation to Lessen Outcomes Due to Decreased Clopidogrel Response after Percutaneous Coronary Intervention (TAILOR-PCI) is the largest cardiovascular genotype-based randomized pragmatic trial (NCT#01742117) to evaluate the role of genotype-guided selection of oral P2Y12 inhibitor therapy in improving ischemic outcomes after PCI. The trial has been extended from the original 12- to 24-month follow-up, using study coordinator-initiated telephone visits. TAILOR-PCI Digital Study tests the feasibility of extending the trial follow-up in a subset of patients for up to 24 months using state-of-the-art digital solutions. The rationale, design, and approach of extended digital study of patients recruited into a large, international, multi-center clinical trial has not been previously described. METHODS: A total of 930 patients from U.S. and Canadian sites previously enrolled in the 5,302 patient TAILOR-PCI trial within 23 months of randomization are invited by mail to the Digital Study website (http://tailorpci.eurekaplatform.org) and by up to 2 recruiting telephone calls. Eureka, a direct-to-participant digital research platform, is used to consent and collect prospective data on patients for the digital study. Patients are asked to answer health-related surveys at fixed intervals using the Eureka mobile app and or desktop platform. The likelihood of patients enrolled in a randomized clinical trial transitioning to a registry using digital technology, the reasons for nonparticipation and engagement rates are evaluated. To capture hospitalizations, patients may optionally enable geofencing, a process that allows background location tracking and triggering of surveys if a hospital visit greater than 4 hours is detected. In addition, patients answer digital hospitalization surveys every month. Hospitalization data received from the Digital Study will be compared to data collected from study coordinator telephone visits during the same time frame. CONCLUSIONS: The TAILOR-PCI Digital Study evaluates the feasibility of transitioning a large multicenter randomized clinical trial to a digital registry. The study could provide evidence for the ability of digital technology to follow clinical trial patients and to ascertain trial-related events thus also building the foundation for conducting digital clinical trials. Such a digital approach may be especially pertinent in the era of COVID-19.