Single Antiplatelet Therapy Group Research Articles

Antithrombotic Strategies After Transcatheter Aortic Valve Replacement in Patients Without an Indication of Oral Anticoagulants: A Network Meta-Analysis of Randomized Controlled Trials.

Single-antiplatelet therapy (SAPT) has been a standard of care posttranscatheter aortic valve replacement with no clear evidence exist using direct oral anticoagulants (DOACs), vitamin K antagonists (VKA), or dual antiplatelet agents (DAPT); thus we aim to compare the safety and efficacy of the various antithrombotic strategies after transcatheter aortic valve replacement. We performed a network meta-analysis using a frequentist framework, pooling dichotomous outcomes using risk ratio (RR), and continuous data using mean difference, along with the corresponding 95% confidence interval (CI). Nine randomized controlled trials with 4193 patients were included, 567 patients were in the VKA group, 591 patients in the SAPT group, 1571 patients in the DAPT group, and 1464 patients in the DOACs group. Only DOAC showed a statistically significant higher risk of all-cause mortality [RR of 1.88 (95% CI: 1.07-3.28)] with no statistically significant difference between our arms in terms of mortality. For minor bleeding, DAPT had a significant higher risk with RR of 1.53 (95% CI: 1.04-2.25), while for major bleeding, DAPT and DOAC had a significant higher risk with RR of 2.36 (95% CI: 1.27-4.40) and 4.74 (95% CI: 2.05-10.92), respectively. There was no significant difference in terms of stroke and life-threatening bleeding. Moreover, only DOAC showed a significantly lower risk for valve thrombosis, when compared to other strategies [RR: 0.24 (95% CI: 0.13-0.46)]. Overall, SAPT had lower major bleeding events compared to other arms. There were no differences in the outcomes of stroke, myocardial infarction, or life-threatening bleeding outcomes. However, DOACs significantly reduced valve thrombosis compared to VKAs.

Optimal duration of dual antiplatelet therapy for minor stroke within 72 hours of symptom onset: a prospective cohort study

ObjectivesDespite the potential spillover effect, the optimal duration of dual antiplatelet therapy for minor stroke within 72 hours of symptom onset is still uncertain.MethodsSafety and Efficacy of Aspirin-Clopidogrel in Acute...

Role of Antiplatelet Therapy in Patients Managed for Complex Aortic Aneurysms using Fenestrated or Branched Endovascular Repair

Despite the increasing number of fenestrated/branched endovascular aortic repair (f/bEVAR) procedures, evidence on post-operative antiplatelet therapy is lacking. This study aimed to investigate the role of single antiplatelet therapy (SAPT) vs. double antiplatelet therapy (DAPT) after f/bEVAR on 30 day and follow up outcomes. A multicentre retrospective analysis was conducted, including f/bEVAR patients managed from 1 January 2018 to 31 December 2022. Comparative outcomes were assessed according to post-operative antiplatelet therapy. The cohort was divided into the SAPT group (acetylsalicylic acid [ASA] or clopidogrel) and DAPT group (ASA and clopidogrel). The duration of SAPT or DAPT was one to six months. Primary outcomes were 30 day death, and cardiovascular ischaemic and major haemorrhagic events. Secondary outcomes were survival and target vessel (TV) patency during follow up. A total of 1 430 patients were included: 955 under SAPT and 475 under DAPT. The 30 day mortality was similar (SAPT 2.1% vs. DAPT 1.5%; p = .42). Cardiovascular ischaemic events were lower in the DAPT group (SAPT 11.9% vs. DAPT 8.2%; p = .040), with DAPT being an independent protector for acute mesenteric (p = .009) and lower limb ischaemia (p = .020). No difference was found in 30 day major haemorrhagic events (SAPT 7.5% vs. DAPT 6.3%; p = .40). The mean follow up was 21.8 ± 2.9 months. Cox regression showed no cofounders on survival, with similar rates between groups (log rank p = .71). DAPT patients presented higher TV patency (SAPT 93.4%, standard error [SE] 0.7% vs. DAPT 96.6%, SE 0.7%; log rank p = .007) at thirty six months. Cox regression revealed bEVAR as a predictor of worse TV patency (hazard ratio 2.03, 95% confidence interval 1.36 - 3.03; p < .001). DAPT was related to higher patency within bEVAR patients (SAPT 87.2%, SE 2.1% vs. DAPT 94.9%, SE 1.9%; p < .001). DAPT after f/bEVAR was associated with lower risk of cardiovascular ischaemic events and higher TV patency, especially in bEVAR cases. No difference in major haemorrhagic events was observed at 30 days.

Safety and efficacy of single antiplatelet therapy in a large cohort of patients treated with sirolimus-coated balloon: Post hoc analysis from the prospective EASTBOURNE registry

BackgroundDrug coated balloons (DCB) are potentially less thrombogenic than drug eluting stents (DES). AimsTo explore the safety and the feasibility of single antiplatelet therapy in percutaneous coronary intervention with sirolimus-coated balloons. MethodsThe All-comers Sirolimus-coated Balloon European Registry (EASTBOURNE) is a prospective investigator-driven registry assessing the performance of a novel sirolimus-coated balloon (SCB) in a real-world population. This prespecified post hoc analysis aimed at comparing the outcome in patients prescribed either single antiplatelet therapy (SAPT) or dual antiplatelet therapy (DAPT); choice of antiplatelet agent and duration of the regimen were at operator's discretion in both groups. Primary endpoint was target lesion revascularization (TLR) at 12 months. Secondary endpoints were bleeding grade 3–5 according to The Bleeding Academic Research Consortium (BARC) criteria and major adverse cardiovascular events (MACE) at 12 months follow-up. ResultsAmong 2123 patients enrolled in the study between September 2016 and November 2020, 113 patients (5.8 %) received SAPT while 1826 patients (94.1 %) received DAPT after SCB. The majority of the patients underwent DCB PCI for de novo lesions (n = 1091, 56.3 %) while 848 patients (47.7 %) had DCB revascularization for in-stent restenosis. No cases of TLR occurred in the SAPT group within one month after the index procedure, and no acute occlusive events were recorded during follow up in patients taking a single antiplatelet agent. Moreover, no differences in terms of TLR were observed between SAPT vs DAPT regimens nor in case of de novo treatment with an overall rate of TLR at 12 months of 7.7 % for SAPT and 5.6 % for DAPT (p = 0.6). The cumulative rate of MACE at 12 months was not different between SAPT and DAPT regimens (n = 12 [11.2 %] vs. n = 162 [8.9 %], p = 0.4), and results were consistent in the de novo and in-stent restenosis groups. ConclusionsOur post hoc analysis of the EASTBOURNE registry suggests that the use of single antiplatelet agent after sirolimus-DCB PCI for both de novo or in-stent restenosis lesions is safe and effective and can help to contain the risk of bleeding in a selected population. Condensed abstractThe manuscript aims to explore the feasibility of a single antiplatelet regimen following angioplasty using drug coated balloon with sirolimus. Among 2123 patients treated with sirolimus coated balloon (SCB), 113 patients (5.8 %) received a single antiplatelet therapy (SAPT) while 1826 patients (94.1 %) received dual antiplatelet therapy DAPT. No cases of target lesion revascularization occurred in the SAPT group within one month after the index procedure, and no acute occlusive events were recorded during follow up in patients taking a single antiplatelet agent. The cumulative rate of major adverse cardiovascular events at 12 months was not different between SAPT and DAPT regimens and results were consistent in the de novo and in-stent restenosis groups.

Pretreatment antithrombotic strategies in non-ST elevation acute coronary syndromes in contemporaneous clinical practice

BackgroundPretreatment antithrombotic strategies in non-ST elevation acute coronary syndromes (NSTE-ACS) during hospitalization is still a matter of contention within the cardiology community. Our aim was to analyze in-hospital and one-year follow-up outcomes of patients with NSTE-ACS pretreated with dual antiplatelet therapy (DAPT) versus single antiplatelet therapy (SAPT). MethodsA retrospective study was carried out with NSTE-ACS patients who planned to undergo an invasive strategy and were included in the Portuguese Registry of ACS between 2018 and 2021. A composite primary outcome (in-hospital re-infarction, stroke, heart failure, hemorrhage, death) was compared regarding antiplatelet strategy (DAPT versus SAPT). Secondary outcomes were defined as one-year all-cause mortality and one-year cardiovascular rehospitalization. ResultsA total of 1469 patients were included, with a mean age of 66 ± 12 years, and 73.9 % were male. The DAPT regime was used in 38.2 % of patients and SAPT in 61.8 % of patients. NSTE myocardial infarction was the most frequent presentation (88.5 %). Revascularization was performed within 24 h in 55.2% of patients. Time until revascularization >24 h occurred in 44.8% of patients, with 16.5% of these between [24 h–48 h], 10.6% in [48 h–72 h] and 17.6% > 72 h. The primary outcome was more frequently observed in the SAPT group (10.4 %, p = 0.033), mainly driven by more ischemic events. Time until revascularization >72 h and the SAPT regime were independent predictors of the primary outcome (OR 3.09, p = 0.005, and OR 2.03, p = 0.008, respectively). ConclusionNSTE-ACS patients pretreated with SAPT had worse in-hospital outcomes. This difference can probably be explained by time until revascularization delay.

Early 6 months usage of single anTiplAtelet OR anTicoAgulant followed by single antiplatelet after transcatheter aortic valve replacement: protocol for a multicentre, open-label, randomised controlled clinical trial

IntroductionThe strategy for initiating antithrombotic therapy to prevent bioprosthetic valve thrombosis (BPVT) after transcatheter aortic valve replacement (TAVR) remains uncertain. There is still lacking evidence on the efficacy and safety...

Increased anti-thrombotic therapy is associated with decreased major adverse limb events in patients with low wound and foot infection scores.

The optimal anti-thrombotic management of patients after lower extremity bypass has yet to be fully elucidated, in part due to significant heterogeneity in patient presentation and practice patterns. The Wound, Ischemia, and foot Infection (WIfI) score is a validated scoring system to assist in the management of patients with chronic limb threatening ischemia (CLTI). We hypothesized that performing a restriction analysis based on WIFI scores would assist in the postoperative anti-thrombotic management of patients undergoing infrainguinal bypass. A retrospective cohort of infrainguinal bypass procedures completed at a single hospital system between January 2018 and January 2021 was selected, and preoperative WIfI scores were extracted for each patient. Patients with either Wound scores of 2 and 3, or Ischemia Scores of 0 and 1, or Foot Infection Scores of 3 were excluded. Based on the type of anti-thrombotic regimen on discharge, demographics, comorbidities, type of bypass, 30-day rates of graft occlusion, major amputation, mortality, and major adverse limb events (MALE) were analyzed. Statistical analysis included t-tests, chi square tests, and time-to-event survival analysis. 230 procedures were included in the study. 69 (30.0%) patients were discharged on single antiplatelet therapy (SAPT), compared to 161 (70.0%) who were discharged on either dual antiplatelet therapy or anticoagulation (DAPT/AC). There was a higher prevalence of bypasses using prosthetic conduit in the DAPT/AC group (45.9 vs 31.8%, p = .047); no other demographic or procedural variable analyzed had any significant differences. At 30-days postoperatively, there was no significant difference in postoperative reintervention rates, however, the DAPT/AC group had significantly lower rates of mortality (1.2 vs 7.2%, p = .01), major amputation (1.2% vs 5.8%, p = .04), and MALE (3.7 vs 13.0%, p < .01). There were no significant differences in bleeding complications. Survival analysis demonstrated that MALE-free survival was higher in the DAPT/AC group compared to the SAPT group (p < .01). On Cox regression analysis, DAPT/AC was associated with significantly decreased rates of MALE + mortality (Hazard Ratio (HR) 0.20 [0.06 - 0.66]). Lower extremity bypasses patients with low Wound and low foot Infection scores who are discharged on DAPT/AC postoperatively have a significantly higher 30-day MALE-free survival rate compared to patients discharged on SAPT; consideration could be made to preferentially discharge such post-bypass patients on DAPT/AC.

Eligibility to Intensified Antithrombotic Regimens for Secondary Prevention in Patients Who Underwent Percutaneous Coronary Intervention

Single antiplatelet therapy (SAPT) and intensified antithrombotic regimens (prolonged dual antiplatelet therapy [DAPT] or dual pathway inhibition [DPI]) are recommended for secondary prevention in patients who underwent percutaneous coronary intervention (PCI) after initial DAPT. We aimed to characterize eligibility to such strategies and to explore to what extent guidelines are applied in clinical practice. Patients who underwent PCI for acute or chronic coronary syndrome who completed initial DAPT were analyzed from a prospective registry. Patients were categorized into SAPT, prolonged DAPT/DPI, or DPI groups as per guideline indication by using a risk stratification algorithm. Predictors of receiving intensified regimens and the divergency of practice from guidelines were investigated. Between October 2019 and September 2021, a total of 819 patients were included. Based on the guidelines, 83.7% of patients qualified for SAPT, 9.6% for any intensified regimen (i.e., prolonged DAPT or DPI), and 6.7% for DPI only. At multivariable analysis, patients were more likely to receive an intensified regimen if they had diabetes, dyslipidemia, peripheral artery disease, multivessel disease, or previous myocardial infarction. Conversely, they were less likely to receive an intensified regimen if they had atrial fibrillation, chronic kidney disease, or previous stroke. Guidelines were not followed in 18.3% of cases. In particular, only 14.3% of candidates to intensified regimens were treated accordingly. In conclusion, although the majority of patients who underwent PCI after the initial period of DAPT were eligible for SAPT, 1 out of 6 had an indication to intensified regimens. However, such intensified regimens were underused among eligible patients.

Medium-Term Outcomes of the Different Antithrombotic Regimens After Transcatheter Aortic Valve Implantation

Bioprosthetic valve thrombosis is associated with accelerated bioprosthesis degeneration and valve re-replacement. Whether 3-month warfarin use after transcatheter aortic valve implantation (TAVI) protects against such consequences is unknown. We aimed to investigate if 3-month warfarin treatment after TAVI is associated with better outcomes than dual antiplatelet therapy (DAPT) and single antiplatelet therapy (SAPT) at medium-term follow-up. Adults who underwent TAVI were identified retrospectively (n = 1,501) and classified into warfarin, DAPT, and SAPT groups based on antithrombotic regimen received. Patients with atrial fibrillation were excluded. Outcomes and valve hemodynamics were compared between the groups. Annualized change from baseline in mean gradients and effective orifice area at last follow-up echocardiography was calculated. Overall, 844 patients were included (mean age: 80 ± 9 years, 43% women; 633 receiving warfarin, 164 DAPT, and 47 SAPT). Median time to follow-up was 2.5 (interquartile range 1.2 to 3.9) years. There were no differences in the adjusted outcome end points of ischemic stroke, death, valve re-replacement/intervention, structural valve degeneration, or their composite end point at follow-up. Annualized change in aortic valve area was significantly higher in DAPT (−0.11 [0.19] cm2/year) than warfarin (−0.06 [0.25] cm2/y, p = 0.03), but annualized change in mean gradients was not different (p >0.05). In conclusion, antithrombotic regimen, including warfarin, after TAVI was associated with marginally lower decrease in aortic valve area but no difference in medium-term clinical outcomes compared with DAPT and SAPT. Bioprosthetic valve thrombosis is associated with accelerated bioprosthesis degeneration and valve re-replacement. Whether 3-month warfarin use after transcatheter aortic valve implantation (TAVI) protects against such consequences is unknown. We aimed to investigate if 3-month warfarin treatment after TAVI is associated with better outcomes than dual antiplatelet therapy (DAPT) and single antiplatelet therapy (SAPT) at medium-term follow-up. Adults who underwent TAVI were identified retrospectively (n = 1,501) and classified into warfarin, DAPT, and SAPT groups based on antithrombotic regimen received. Patients with atrial fibrillation were excluded. Outcomes and valve hemodynamics were compared between the groups. Annualized change from baseline in mean gradients and effective orifice area at last follow-up echocardiography was calculated. Overall, 844 patients were included (mean age: 80 ± 9 years, 43% women; 633 receiving warfarin, 164 DAPT, and 47 SAPT). Median time to follow-up was 2.5 (interquartile range 1.2 to 3.9) years. There were no differences in the adjusted outcome end points of ischemic stroke, death, valve re-replacement/intervention, structural valve degeneration, or their composite end point at follow-up. Annualized change in aortic valve area was significantly higher in DAPT (−0.11 [0.19] cm2/year) than warfarin (−0.06 [0.25] cm2/y, p = 0.03), but annualized change in mean gradients was not different (p >0.05). In conclusion, antithrombotic regimen, including warfarin, after TAVI was associated with marginally lower decrease in aortic valve area but no difference in medium-term clinical outcomes compared with DAPT and SAPT.

Trends in antiplatelet strategies 12-months following coronary stent placement in anticoagulated patients

BackgroundAntithrombotic guidelines for patients undergoing percutaneous coronary interventions (PCIs) and also requiring anticoagulant medications are evolving. This study describes changes to antithrombotic therapy and associated outcomes 12-months following PCI in patients requiring ongoing anticoagulation therapy.MethodsRecords of patients identified from queries of electronic medical records were manually reviewed to verify changes to antithrombotic therapy from discharge to 12-months and at 12-months following PCI, and episodes of major bleeding, clinically relevant non-major bleeding (CRNMB), major adverse cardiovascular or neurological events (MACNE), and all-cause mortality outcomes during an additional 6-months follow-up.ResultsPatients (n = 120) receiving anticoagulation therapy at 12-months post PCI were classified into the following groups according to antiplatelet therapy status: no antiplatelet therapy (n = 16), single antiplatelet therapy (SAPT) (n = 85), and dual antiplatelet therapy (DAPT) (n = 19). Between 12- and 18-months following PCI there were 2 major bleeds, 7 CRNMB, 6 MACNE, 2 venous thromboembolisms, and 5 deaths. All but one bleeding episode occurred in the SAPT group. The odds of remaining on DAPT at 12-months were higher in patients who had PCI for acute coronary syndrome (odds ratio [OR] 2.91, 95% confidence interval [CI] 0.96, 8.77), and in those experiencing MACNE in the 12-months following PCI (OR 1.95, 95% CI 0.67, 5.66), but these associations were not statistically significant.ConclusionMost anticoagulated patients were continued on antiplatelet therapy 12-months post PCI. Bleeding was numerically more common in anticoagulated patients continuing SAPT therapy beyond 12 months. There was significant variability in antithrombotic prescribing patterns 12-months post PCI suggesting a potential opportunity for standardizing care in this patient population.

Dual Antiplatelet Therapy After an Acute Nonminor Stroke.

In select patients with minor ischemic stroke, dual antiplatelet therapy (DAPT) with aspirin plus clopidogrel is recommended if initiated early and continued for 21 to 90 days. Dual antiplatelet therapy use, in a broader population, has shown to increase the risk of bleeding without an increased antithrombotic benefit. An ongoing area of uncertainty is whether DAPT would benefit the nonminor stroke population when continued for 21 to 90 days.?s. To describe the effects of DAPT after a nonminor stroke. This single-center, retrospective cohort study included patients initiated on antiplatelet therapy started within 1 week of symptom onset for a nonminor ischemic stroke from January 2013 to January 2020. Patients with any bleeding disorder or National Institutes of Health Stroke Scale score <4 were excluded. The primary endpoint was major bleeding at 3 months. Secondary endpoints included recurrent stroke and minor bleeding. A total of 158 patients met criteria for inclusion. Ninety (57%) received DAPT, and 68 (43%) received single antiplatelet therapy (SAPT). The primary endpoint occurred in 3 patients in the DAPT group and 1 patient in the SAPT group (P = 0.463). Minor bleeding occurred in 1 patient receiving DAPT and 2 patients receiving SAPT (P = 0.402). There were 10 patients in the DAPT group and 5 patients in the SAPT group who experienced recurrent stroke or transient ischemic attack (P = 0.429). Limitations of this study include the retrospective single-center study design. There was a comparable risk of bleeding and recurrent stroke between DAPT and SAPT in patients admitted with an acute nonminor stroke.

53: SAFETY OF PERCUTANEOUS DILATATIONAL TRACHEOSTOMY IN PATIENTS RECEIVING ANTIPLATELET THERAPY

Introduction: Tracheostomy is one of the most frequent surgical procedures carried out in critically ill patients. The most popular technique today is the percutaneous dilatational tracheostomy (PDT) which uses serial dilators over a guide wire and is usually done at the bedside in the intensive care unit (ICU) under bronchoscopic guidance. Antiplatelet agents have become a mainstay therapy for vascular diseases; yet they increase the risk of bleeding. The aim of this study is to determine the bleeding risk for patients on antiplatelet therapy who underwent PDT. Methods: A retrospective analysis of patients who underwent PDT admitted to ICU between 2006 and 2021. All data were extracted from electronic health record (EPIC) and operative reports. Minor bleeding is defined as bleeding requiring application of temporary pressure or change of dressing. Major bleeding is defined as bleeding requiring packing with surgicel or transfusion of red blood cells, fresh frozen plasma or platelets. Antiplatelet therapy (APT) is defined as receiving therapy up to and within 24 hours of PDT. Single antiplatelet therapy (SAT) is ASA alone and dual antiplatelet therapy (DAT) is ASA/clopidogrel combination. Results: A total of 677 PDTs were identified and analyzed (567 patients that did not receive antiplatelet therapy [NAT group] and 100 APT group [93 SAT and 17 DAT]). Compared to the NAT group, the APT group were older (71 +/- 12 vs 58 +/- 20, p = 0.0001), had similar gender (male: 60 % vs 60 %, p = 1.0), and similar BMI (29 +/- 9 vs 28 +/- 7, p = 0.2). For minor bleeding (5.1 % in NAT group), the SAT group and DAT group had more bleeding (17 % for SAT, p = 0.0001, and 17.6 % for DAT, p = 0.02). Major bleeding did not significantly differ between SAT and NAT groups (1.1 % vs 0.4 %, p = 0.2), but was significantly higher for DAT group compared to NAT group (5.9 % vs 0.4 %, p = 0.003). Conclusions: In a large single center, there was no significant major bleeding when PDT was performed while patients are on ASA, but there was significantly more major bleeding when patients were on both ASA and clopidogrel. This data should be confirmed in large multicenter prospective studies.

512 ACADEMIC RESEARCH CONSORTIUM HIGH BLEEDING RISK CRITERIA ASSOCIATED WITH ONE-YEAR NACES IN A MULTICENTER COHORT OF OLDEST OLD STEMI PATIENTS

Abstract Introduction The balance between thrombotic and bleeding events after myocardial revascularization is of paramount importance. Patients with higher bleeding risk are at high risk for complications. Age and frailty are also major risk factors for complications. We sought to evaluate the incidence of major bleeding events (BE) and their impact on prognosis in a real life oldest old (i.e. &amp;gt;85 years) ST elevation myocardial infarction (STEMI) patients population. Methods We evaluated all consecutive oldest old STEMI patients hospitalized in two hub-centers between January 2010 and June 2021. Patients were stratified according to Academic Research Consortium for High Bleeding Risk (ARC-HBR) in high bleeding risk (HR) and non-HR (nHR) patients. BE were defined according to the Bleeding Academic Research Consortium (BARC) criteria, BARC 3 or 5. Patients were also divided in groups according to anti-thrombotic therapy (AT) regimens at discharge: single antiplatelet therapy (SAPT), dual antiplatelet therapy (DAPT) or triple therapy (DAPT plus oral anticoagulation) (TT). Net adverse clinical event (NACE) was defined as a composite of all-cause mortality, myocardial infarction, stroke, or major bleeding. Follow-up data were determined from local clinical records during a twelve-months period. Results 340 oldest old (mean age 88.6 ± 2.9 years, 52.6% female) STEMI patients were eligible for the analysis. 161 patients (47.4%) were categorized as nHR and 179 patients (52.6%) as HR. AT regimens at discharge were: 28 patients with SAPT (8.2%), 276 with DAPT (81.2%) and 36 with TT (10.6%). The overall incidence of BE was 4.6% within 12 months, without difference between nHR and HR patients (3.0% vs 5.9%, p=0.16). No BE were found in the SAPT group while the incidence of BE in the HR group was not statistically different between the DAPT and TT regimens (11.2% vs 9.5%; p=0.8). The incidence of NACE was statistically higher in HR than nHR patients (40.9% vs 25.5%, p&amp;lt;0.01) at 1-year. In addition, time-to-NACE was statistically inferior in HR group than nHR group (256.2 days vs 294.2 days, p&amp;lt;0.01) (Figure). Conclusions Our oldest old STEMI population was characterized by a large proportion of HR patients according to ARC-HBR criteria. This population experienced a higher rate of NACE in a shorter time when compared to nHR patients in the same age group.

Dual versus Single Antiplatelet Therapy in Medically Treated Acute Myocardial Infarction Patients with Baseline Thrombocytopenia - Insights from a Multi-Institute Cohort Study.

The safety and efficacy of dual antiplatelet therapy (DAPT) in medically treated acute myocardial infarction (AMI) patients with baseline thrombocytopenia (platelet count < 150 × 103/uL) are unclear. In this multi-institute retrospective cohort study, we included 468 patients with medically treated AMI with baseline thrombocytopenia and separated them into single antiplatelet therapy (SAPT) and DAPT groups according to the discharge anti-thrombotic strategy. The primary outcome was net clinical adverse events (NACEs), defined as a composite of death, ischemic events (myocardial infarction, ischemic stroke, and transient ischemic attack), and major bleeding within 30 days. There were 168 patients in the SAPT group (100 taking aspirin and 68 taking clopidogrel) and 300 in the DAPT group. A primary outcome occurred in 35 (24.11 per 100 patient-months) patients in the SAPT group and 39 (14.26 per 100 patient-months) patients in the DAPT group [adjusted hazard ratio (HR): 0.67; 95% confidence interval (CI): 0.40-1.10; p = 0.1145]. Kaplan-Meier curves showed favorable results in the DAPT group (log-rank p = 0.0243). Bleeding events occurred in 18 (10.71 per 100 patient-months) patients in the SAPT group and 18 (6.40 per 100 patient-months) patients in the DAPT group (adjusted HR: 0.66; 95% CI: 0.32-1.36; p = 0.2573). DAPT versus SAPT as discharge anti-thrombotic strategy in thrombocytopenic patients with medically treated AMI did not significantly improve NACEs at 30 days. However, there was a trend towards favorable outcomes in the DAPT group. These results should be interpreted carefully with respect to the relatively limited trial population and study design.

Additional Effects of Antiplatelet Therapy on Anticoagulant Agents in Patients With Bioprosthetic Valves and Atrial Fibrillation.

The additional effects of single-antiplatelet therapy (SAPT) on anticoagulant therapy are still unclear in patients with atrial fibrillation (AF) after bioprosthetic valve replacement.Methods and Results:We conducted a subanalysis of a multicenter, retrospective, observational registry of patients with bioprosthetic valves and AF in Japan. Patients administered anticoagulants alone comprised the ACA group (n=107), and patients given concomitant SAPT and anticoagulant therapy comprised the On SAPT group (n=82). The primary efficacy endpoint was the incidence of stroke/systemic embolism, and the primary safety endpoint was the incidence of major bleeding. The observation period was 46.3±24.6 months. The primary efficacy endpoint occurred in 12 patients, and the cumulative incidence of primary efficacy events was significantly higher in the ACA group compared with the On SAPT group (P=0.039). The primary safety endpoint occurred in 22 patients, and the cumulative incidence of primary safety events was similar between groups (P=0.66). No differences between the groups were observed for cardiac events. Additional SAPT on anticoagulant therapy in patients with bioprosthetic valves and AF was associated with a reduction in stroke/systemic embolic events, although the cumulative incidence of bleeding was similar, regardless of additional SAPT. These findings suggest that additional SAPT on anticoagulant therapy may be safe and effective in real-world clinical settings.

Dual Antiplatelet Therapy in Patients With Minor Stroke Receiving Intravenous Thrombolysis.

IntroductionConcern over the potential severe bleeding risk of dual antiplatelet therapy for patients with minor stroke after intravenous thrombolysis (IVT) leads to different antiplatelet strategies in the secondary prevention of stroke. Our aim was to investigate the effect of dual antiplatelet therapy on patients with minor ischemic stroke receiving IVT.MethodsFrom November 2016 to April 2021, a total of 855 consecutive patients who received IVT were observed. We collected and analyzed demographic characteristics, medical history, clinical information, and important time metrics of patients with minor ischemic stroke. Comparative and multivariate logistic regression analyses were used to explore the clinical significance of single or dual antiplatelet therapy after IVT. Propensity score matching analyses (1:1 matching including baseline characteristics of patients) were also performed.ResultsA total of 245 patients were enrolled in the study (118 patients in the single antiplatelet therapy group and 127 patients in the dual antiplatelet group). No significant difference was found in baseline characteristics except stroke etiology (p < 0.001) for patients with minor stroke. The dual antiplatelet group showed a higher proportion of 90-day modified Rankin Scale (mRS) (0–1) than the single antiplatelet group (p = 0.030). Furthermore, patients receiving dual antiplatelet therapy had excellent outcomes (90-day mRS 0–1) after adjustment (odds ratio [OR] 2.76, 95% CI 1.27–6.01, p = 0.010). Other secondary outcomes (recurrent stroke within 90 days, symptomatic intracerebral hemorrhage, and early neurological deterioration) were not significantly different between the two groups. These findings were generally consistent in propensity score analyses.ConclusionsDual antiplatelet therapy may be a potential therapeutic approach in patients with minor stroke receiving IVT. Further randomized controlled trials are required to confirm this finding.

240 Left atrial appendage occlusion: safety, efficacy, and antiplatelet therapy in a single-centre experience

Abstract Aims Oral anticoagulation (OAC) is the cornerstone therapy for stroke prevention in patients with atrial fibrillation (AF). However, a not negligible proportion of AF patients experiences major bleeding events or is affected by concomitant disorders that represent a contraindication for OAC. Left atrial appendage occlusion (LAAO) has emerged as an effective strategy to minimize the risk of thromboembolism in AF patients (without moderate/severe mitral stenosis or mechanical prosthetic heart valves) that are poor candidates for OAC. After the procedure variable regimens of antithrombotic therapy are prescribed, in order to provide protection and prevent device-related thrombus (DRT). The optimal post-procedural antithrombotic strategy remains to be assessed. Therefore, we aim to evaluate the safety and efficacy of LAAO procedure and the relationship between antiplatelet therapy and outcomes at long-term follow-up. Methods and results We conducted a retrospective observational study including consecutive AF patients who underwent LAAO at Azienda Ospedaliero-Universitaria of Parma from October 2010 to June 2021. The incidence of major ischaemic events [DRT, ischaemic stroke, transient ischaemic attack (TIA) and systemic embolism], Bleeding Academic Research Consortium major bleeding events and net adverse clinical events (major ischaemic + bleeding events) were assessed at follow-up. We enrolled 130 patients [median age 77 years (73; 81)] characterized by both high ischaemic (mean CHA2DS2-VASc 4.48) and bleeding risk (mean HAS-BLED 3.24). Technical procedure success was achieved in 123 (94.6%). Thirty-nine (31.7%) patients were discharged on short (≤1 month)-dual antiplatelet therapy (DAPT); 35 (28.5%) on long-DAPT (1–12 months) and 49 (39.8%) on single antiplatelet therapy (SAPT). Antiplatelet therapy was chosen after multidisciplinary discussion on the basis on the hemorrhagic risk [mean HAS-BLED 3.55; 3.11; 2.97 (P = 0.038) in SAPT, short-DAPT and long-DAPT groups respectively], while no differences were observed in ischaemic risk between the three groups. Clinical follow-up was completed in 119 (98.2%) of successfully implanted patients. After a median follow-up of 31 ± 16 months, 24 (20.2%) patients had a major adverse event: 11 (9.2%) ischaemic events [8 (6.7%) strokes and 3 (2.5%) TIA] and 13 (10.9%) major bleedings. Patients on short-DAPT had a significantly lower occurrence of major bleedings [0 vs. 4 (11.4%) on long-DAPT vs. 9 (18.4%) on SAPT; P = 0.033] and net adverse clinical events [3 (7.7%) vs. 7 (20.0%) on long-DAPT vs. 14 (28.6%) on SAPT; P = 0.005] compared to the other two groups, while no difference was observed in the incidence of major ischaemic events [3 (7.7%) on short-DAPT vs. 3 (8.6%) on long-DAPT vs. 5 (10.2%) on SAPT; P = 0.340]. Conclusions In our cohort of AF patients with a contraindication for OAC therapy, LAAO showed high procedural success; however, long-term major ischaemic and bleeding events were not negligible. Short-DAPT therapy turned out to be the best antiplatelet regimen regarding net ischaemic-hemorrhagic balance. Evidence from well-designed randomized trials would be desirable to guide a tailored approach in the selection of post-procedural antithrombotic regimens.

Abstract 9424: Single versus Dual Antiplatelet Therapy for Stroke Prevention Following Left Atrial Appendage Occlusion in Patients With High Bleeding Risk

Introduction: The optimal antiplatelet therapy following Left atrial appendage occlusion (LAAO) in atrial fibrillation patients who are not candidates for long-term oral anticoagulation therapy (OAC) is subject to debate. Hypothesis: Is single antiplatelet therapy (SAPT) safe and effective when compared to dual antiplatelet therapy (DAPT) in patients with high bleeding risk? Methods: We conducted a comprehensive search for all studies that compared the use of SAPT with DAPT following LAAO for patients in whom OAC is deemed highly risky or contraindicated. The outcomes of our study were device-related thrombosis (DRT), stroke and systemic embolization (SSE), and major bleeding (MB). The risk ratio (RR) with 95% confidence intervals (CIs) are presented as summary statistics and were calculated using a random-effects model. Results: A total of 15 observational studies with 3231 patients (SAPT, n=1036; DAPT, n=2195; 64.5% men; median follow-up duration 12 months; mean age 74.7±8.5 years; CHA2DS2-VASc score 4.3±1.6; HASBLED score 3.2±1.2) were included. For DRT, data were available from 10 studies (2910 patients); there was no difference between SAPT and DAPT groups (2.6% vs. 2.3%; RR: 1.41; 95%CI: 0.77-2.59; P=0.26; I 2 :0%). For SSE (8 studies, 959 patients); although numerically more events were observed in the SAPT group, there was no statistical difference between the two groups in the pooled analysis (2.9% vs. 1.5%; RR: 5.43; 95%CI: 0.74-39.81; P=0.1; I 2 :78%). Finally, for MB (8 studies, 1818 patients); although numerically more events were observed in the DAPT group, there was no statistical difference between the two arms (2.3% vs. 3.2%; RR: 1.90; 95%CI: 0.46-7.87; P=0.37; I 2 :72%). Conclusions: Our study showed comparable safety and efficacy profiles for SAPT and DAPT after LAAO. Adequately powered randomized studies determining the optimal antithrombotic therapy in the first weeks after LAAO are warranted in patients at high risk for bleeding.

Effects of single versus dual antiplatelet therapy on the adverse events after transcatheter aortic valve implantation: A meta-analysis.

Dual antiplatelet therapy (DAPT) was currently recommended for transcatheter aortic valve implantation (TAVI) postoperative management in clinical application. However, POPular‐TAVI trial showed DAPT increased the incidence of adverse events compared to single antiplatelet therapy (SAPT). Herein, we performed a meta‐analysis to investigate the effect of SAPT versus DAPT on the adverse events after TAVI. Eleven studies were available from PubMed, Embase, Cochrane Library, and Web of Science from inception to April 1, 2021. The pooled effect size was presented as relative risk (RR) with 95% confidence intervals (CIs). The sensitivity analysis was used to assess the stability of analysis results, and Begg's test was applied to evaluate the publication bias. The Cochran Q test and the I 2 statistic were used to evaluate the heterogeneity, and the source of heterogeneity was explored by meta‐regression. A total of 4804 patients were obtained, with 2257 in SAPT group and 2547 in DAPT group. Compared to the DAPT, SAPT was associated with the decreased risk of all‐cause bleeding (RR: 0.51, 95% CI: 0.44–0.61), major bleeding (RR: 0.53, 95% CI: 0.32–0.86), and minor bleeding (RR: 0.58, 95% CI: 0.34–0.98). There were no significant differences in mortality and myocardial infarction events, stroke events, and acute kidney injury between the two groups. SAPT was superior to DAPT in decreasing all‐cause bleeding, major bleeding, and minor bleeding, suggesting that SAPT could be preferentially recommended for TAVI postoperative management in most patients without another indication for DAPT and oral anticoagulation.

Antithrombotic therapy for patients with atrial fibrillation and stable coronary artery disease of 1-year and 3-year after percutaneous coronary intervention: a nationwide population-based study

Abstract Background In a recent trial, rivaroxaban monotherapy was noninferior for efficacy and superior for safety to rivaroxaban plus single antiplatelet therapy, as antithrombotic therapy for patients with atrial fibrillation (AF) and stable coronary artery disease (CAD). However, there are limited data regarding the comparative effectiveness and safety of oral anticoagulant (OAC) monotherapy versus OAC plus single antiplatelet therapy (SAPT) in real-world practice, especially after the introduction of direct oral anticoagulants (DOAC). Purpose To compare the effectiveness, safety, and net clinical benefit of OAC monotherapy to OAC plus SAPT in patients with AF and stable CAD of 1-year and 3-year after percutaneous coronary intervention (PCI) in a contemporary real-world observational cohort. Methods Using the Korean nationwide claims database, we included AF patients who underwent PCI from January 1, 2009 to February 28, 2019. Considering dynamic changes of antithrombotic therapy according to the period after receiving PCI, the index antithrombotic treatment was independently defined at the different time after receiving PCI and we conducted two cohort: 1-year and 3-year after PCI. In each cohort, the baseline characteristics of OAC monotherapy and OAC plus SAPT groups were balanced using inverse probability of treatment weighting (IPTW) methods. To assess clinical outcomes, ischemic stroke, myocardial infarction, major bleeding, and composite clinical outcomes of each outcome were analyzed. Results In cohort with 1-year after PCI, 678 patients with OAC monotherapy and 3159 patients with OAC plus SAPT were included. In cohort with 3-year after PCI, 1038 patients with OAC monotherapy and 2128 patients with OAC plus SAPT were enrolled. The baseline characteristics were well-balanced after IPTW between the two groups in both cohorts. Among total population, about 45% of patients prescribed DOAC as OAC treatment. Among patients with 1-year after PCI, OAC monotherapy and OAC plus SAPT showed comparable results for ischemic stroke, myocardial infarction, major bleeding, and composite clinical outcomes (Figure). In cohort with 3-year after PCI, OAC monotherapy and OAC plus SAPT showed comparable results for ischemic stroke and myocardial infarction, but OAC monotherapy was associated with a lower risk of the composite clinical outcome (hazard ratio [HR] 0.762, 95% confidence interval [CI] 0.607–0.950), mainly driven by reduction of major bleeding risk (HR 0.762, 95% CI 0.607–0.950) compared to OAC plus SAPT (Figure). Conclusion OAC monotherapy might be, at least, comparable choice for patients with AF and stable CAD compared to OAC plus SAPT. In patients with stable CAD more than 3-years after index PCI, OAC monotherapy could be better therapeutic choice to achieve less major bleeding and positive net clinical benefit. Funding Acknowledgement Type of funding sources: None.