Aspirin Monotherapy Groups Research Articles

Aspirin Monotherapy vs No Antiplatelet Therapy in Stable Patients With Coronary Stents Undergoing Low-to-Intermediate Risk Noncardiac Surgery

BackgroundCurrent guidelines recommend the perioperative continuation of aspirin in patients with coronary drug-eluting stents (DES) undergoing noncardiac surgery. However, supporting evidence is limited. ObjectivesThis study aimed to compare continuing aspirin monotherapy vs temporarily holding all antiplatelet therapy before noncardiac surgery in patients with previous DES implantation. MethodsWe randomly assigned patients who had received a DES >1 year previously and were undergoing elective noncardiac surgery either to continue aspirin or to discontinue all antiplatelet agents 5 days before noncardiac surgery. Antiplatelet therapy was recommended to be resumed no later than 48 hours after surgery, unless contraindicated. The primary outcome was a composite of death from any cause, myocardial infarction, stent thrombosis, or stroke between 5 days before and 30 days after noncardiac surgery. ResultsA total of 1,010 patients underwent randomization. Among 926 patients in the modified intention-to-treat population (462 patients in aspirin monotherapy group and 464 patients in the no-antiplatelet therapy group), the primary composite outcome occurred in 3 patients (0.6%) in the aspirin monotherapy group and 4 patients (0.9%) in the no antiplatelet group (difference, −0.2 percentage points; 95% CI: −1.3 to 0.9; P > 0.99). There was no stent thrombosis in either group. The incidence of major bleeding did not differ significantly between groups (6.5% vs 5.2%; P = 0.39), whereas minor bleeding was significantly more frequent in the aspirin group (14.9% vs 10.1%; P = 0.027). ConclusionsAmong patients undergoing low-to-intermediate risk noncardiac surgery >1 year after stent implantation primarily with a DES, in the setting of lower-than-expected event rates, we failed to identify a significant difference between perioperative aspirin monotherapy and no antiplatelet therapy with respect to ischemic outcomes or major bleeding. (Perioperative Antiplatelet Therapy in Patients With Drug-eluting Stent Undergoing Noncardiac Surgery [ASSURE-DES]; NCT02797548)

Antiplatelet therapy after coronary artery bypass surgery: five year follow-up of randomised DACAB trial

ObjectiveTo assess the effect of different antiplatelet strategies on clinical outcomes after coronary artery bypass grafting.DesignFive year follow-up of randomised Different Antiplatelet Therapy Strategy After Coronary Artery Bypass Grafting (DACAB)...

Comparison of Effectiveness and Safety of Dual Antiplatelet Therapy (DAPT) With Clopidogrel and Aspirin Versus Aspirin Monotherapy in Patients With Mild-to-Moderate Stroke and Transient Ischemic Attack: A Systematic Review and Meta-Analysis.

The aim of this meta-analysis was to assess the effectiveness and safety of the combination of clopidogrel and aspirin in patientswith mild ischemic stroke or transient ischemic attack (TIA).The methodologies employed in this meta-analysis strictly followed the commonly used reporting formats for systematic reviews and meta-analyses. The methodologies employed in this meta-analysis strictly followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).Until March 25, 2024, we conducted thorough searches on PubMed, EMBASE (Excerpta Medica Database), and the Cochrane Library to locate studies investigating the efficacy and safety of dual antiplatelet therapy (DAPT) in patients with mild or moderate stroke or TIA. Outcomes assessed in this meta-analysis includedstroke (including ischemicstroke and hemorrhagic stroke), myocardial infarction, all bleeding events, and moderate to severe bleeding events. A total of 12 studies were included in this meta-analysis.The total number of enrolled patients across these studies was 35,369, with 16,957 receiving DAPT and 18,412 receiving aspirin monotherapy. Therisk of developing stroke was significantly lower in patients receiving the combination of clopidogrel and aspirin compared to the aspirin monotherapy group (relative risk (RR): 0.77, 95% confidence interval (CI): 0.72 to 0.83, p-value<0.0001). No significant differences were there in terms of all bleeding events(RR: 1.37, 95% CI: 0.92 to 2.04, p-value: 0.12) and moderate to severe bleeding events(RR: 1.18, 95% CI: 0.86 to 1.63, p-value: 0.30). These findings highlight the importance of carefully weighing the potential benefits against the risks, especially in clinical decision-making for patients with TIA or ischemic stroke. Further research is warranted to elucidate optimal strategies for balancing stroke prevention with bleeding risk mitigation in this patient population.

Abstract 11579: Clopidogrel Monotherapy Associates With Increased Mortality Compared With Aspirin Independently of Cardiometabolic Risk Factors

Introduction: Antiplatelet monotherapy is recommended for prevention of ischaemic events and death following acute coronary syndrome, particularly if contraindications preclude the use of dual antiplatelet therapy. We aimed to scrutinise the effects of clopidogrel vs aspirin when given as secondary prevention monotherapy on mortality independent of baseline cardiometabolic risk factors in a large real-world UK cohort. Methods: Between 2012 and 2017, consecutive patients (n = 12967) discharged on clopidogrel or aspirin monotherapy were enrolled at our institution in London, UK (median follow-up 244 days, IQR 659). The primary endpoint was all-cause mortality. Kaplan-Meier curves with a log rank test were used to compare all-cause mortality between patients discharged on clopidogrel monotherapy vs aspirin monotherapy. Cox proportional hazards models were constructed to investigate the relationship between antiplatelet monotherapy and all-cause mortality in multivariable analyses. Results: Overall, the primary endpoint of all-cause mortality occurred in 2585 (19.9%) patients: 1642 (18.3%) in the aspirin monotherapy group, compared with 943 (23.5%) on clopidogrel monotherapy (log rank p &lt; 0.001), depicted in Figure 1. Clopidogrel monotherapy conferred an 16% increased risk of mortality compared with aspirin in the unadjusted Cox model (HR 1.16, 95% CI 1.07 - 1.25, p &lt; 0.001). Following adjustment for age, ischaemic heart disease, stroke hypertension, heart failure, atrial fibrillation, diabetes mellitus, chronic kidney disease and chronic obstructive pulmonary disease, clopidogrel remained significantly associated with increased mortality (HR 1.09, 95% CI 1.00 - 1.18, p = 0.045). Conclusions: In this large UK cohort, clopidogrel monotherapy associated with increased all-cause mortality compared with aspirin independently of common cardiometabolic comorbidities.

Dual Antiplatelet Therapy Using Cilostazol With Aspirin or Clopidogrel: Subanalysis of the CSPS.com Trial.

Although dual antiplatelet therapy (DAPT) with aspirin and clopidogrel reduces the recurrence of ischemic stroke while significantly increasing the bleeding events compared with monotherapy, the CSPS.com trial (Cilostazol Stroke Prevention Study combination) showed that DAPT using cilostazol was more effective without the bleeding risk. In the CSPS.com trial, aspirin or clopidogrel was used as the underlying antiplatelet drug. The effectiveness and safety of each combination were examined and clarified. In the CSPS.com trial, a multicenter, open-label, randomized controlled study, patients with high-risk, noncardioembolic ischemic stroke 8 to 180 days after onset treated with aspirin or clopidogrel alone at the discretion of the physician in charge were recruited. Patients were randomly assigned to receive either monotherapy or DAPT using cilostazol and followed for 0.5 to 3.5 years. The primary efficacy outcome was first recurrence of ischemic stroke. The safety outcome was severe or life-threatening bleeding. The analysis was based on the underlying antiplatelet agents. A total of 763 patients taking aspirin and 1116 taking clopidogrel were included in the intention-to-treat analysis. Although the clopidogrel group had more risk factors than the aspirin group, the primary efficacy outcome and safety outcome did not differ significantly between the 2 groups. In the aspirin group, the primary efficacy outcome and safety outcome did not differ significantly between the DAPT group and the aspirin-monotherapy group. In the clopidogrel group, the primary end point occurred at a rate of 2.31 per 100 patient-years in the DAPT group and 5.19 per 100 patient-years in the clopidogrel-monotherapy group (hazard ratio, 0.447 [95% CI, 0.258–0.774]). Safety outcome did not differ significantly between groups (0.51 per 100 patient-years versus 0.71 per 100 patient-years, respectively; hazard ratio, 0.730 [95% CI, 0.206–2.588]). The combination of cilostazol and clopidogrel significantly reduced the recurrence of ischemic stroke without increasing the bleeding risk in noncardioembolic, high-risk patients. URL: https://www.clinicaltrials.gov; Unique identifier: NCT01995370. URL: https://www.umin.ac.jp/ctr/; Unique identifier: UMIN000012180.

P2Y12 Inhibitor Monotherapy Is Superior to Aspirin Monotherapy in Chronic Limb-Threatening Ischemia Postendovascular Intervention

Antiplatelet monotherapy is recommended in patients with peripheral arterial disease to reduce adverse limb and cardiovascular events. While there is some evidence of improved outcomes with P2Y12 monotherapy (P2Y12) and dual antiplatelet therapy (DAPT) as compared to aspirin monotherapy (ASA) in the general peripheral arterial disease population, data in chronic limb-threatening ischemia (CLTI) patients is limited and ASA monotherapy continues to be widely prescribed. We aim to compare outcomes of ASA, P2Y12 and DAPT after lower extremity peripheral endovascular intervention (PVI) for CLTI. Patients undergoing index PVI for CLTI were identified from the Vascular Quality Initiative PVI registry. Propensity score matching was used to control for baseline differences in the groups. Kaplan-Meier and Cox regression analysis was used to compare limb salvage (LS), amputation-free survival (AFS) and overall survival (OS). A total of 12,433 index PVI in 11,528 patients were included. Antiplatelet use at follow-up was: 12% none, 31% ASA, 14% P2Y12, and 43% DAPT. Three-year LS was significant improved in DAPT (91.7%) group as compared to P2Y12 (89.4%) and ASA (86.8%) groups (P < .05) (Table). AFS was significantly improved in the DAPT (81.5%) and P2Y12 (79.6%) groups as compared to ASA (74.8%) (P < .05). Similarly, OS was significantly improved in the DAPT (88.9%) and P2Y12 (87.8%) groups as compared to ASA (85.5%) (P < .05). There were no significant differences between P2Y12 and DAPT in OS (P = .62) and AFS (P = .33); however, LS was significantly better in DAPT as compared to P2Y12 (P = .03). P2Y12 monotherapy and DAPT were associated with improved OS, AFS and LS as compared to ASA monotherapy in patients undergoing endovascular interventions for CLTI. P2Y12 monotherapy was superior to ASA monotherapy and comparable to DAPT in their survival and AFS benefit; however, LS was superior in DAPT. P2Y12 monotherapy may be considered in select CLTI patients.TableThree-year limb salvage (LS), amputation-free survival (AFS) and overall survival (OS) ratesASA versus P2Y12P valueP2Y12 versus DAPTP valueOS85.5 ± 1.0% vs 87.8 ± 0.9%.02687.8% ± 0.9% vs 88.9% ± 0.9%.62AFS74.8% ± 1.2% vs 79.6% ± 1.1%<.00179.6% ± 1.1% vs 81.5% ± 1.1%.33LS86.8% ± 0.9% vs 89.5% ± 0.8%.01389.5 ± 0.8% vs 91.7% ± 0.7%.03ASA, Aspirin; DAPT, dual antiplatelet therapy. Open table in a new tab

P328Is there evidence of a rebound increase in platelet aggregation following withdrawal of Aspirin or Ticagrelor in patients who have previously undergone PCI and coronary stenting?

Abstract Introduction In patients treated with coronary stents previous studies have demonstrated an increased risk of acute coronary syndrome in after discontinuation of clopidogrel. In this study, we recruited patients already randomised in the GLOBAL LEADERS study allocated to discontinue aspirin treatment, while remaining on ticagrelor, 1 month after coronary stenting (Ticag MonoRx group) and a control group discontinuing ticagrelor at 6–12 months while remaining on aspirin (ASA MonoRx group). Both groups underwent platelet studies at day 0, prior to discontinuation of aspirin or ticagrelor and then on day 2, 7 and 14 day post cessation with multiple electrode aggregometry. Purpose This study was designed to look for evidence of a rebound increase in platelet aggregation in response to collagen after withdrawal of either aspirin or ticagrelor in patients who have been treated with both drugs after PCI with DES implantation. We needed a sample size of 26 patients in each group for 90% power to detect a mean change in platelet aggregation of 100 AU/min with an alpha of 0.05. The primary outcome measure was change in platelet aggregation in response to collagen between baseline and day 2, day 7 and day 14 following cessation of DAPT. A rebound effect was defined as a &gt;10% increase in collagen induced platelet aggregation on either day 2 or day 7 compared to day 14 post discontinuation of either aspirin or ticagrelor. Methods Patients provided written informed consent and underwent MEA using arachidonic acid (AA), adenosine diphosphate (ADP), thrombin receptor activator peptide (TRAP) and collagen in prespecified concentrations timed at 30 mins post phlebotomy. Results were calculated from the area under the curve and expressed as as whole number aggregation units (AU). Inbuilt QC analysis was used to determine the need for repeat assays. Results Collagen induced platelet aggregation was similar in both groups at day 0 (37 AU vs 34 AU; p=0.687) and at day 2 (55 AU vs 40 AU; p=0.12). By day 7, patients on ticagrelor monotherapy had higher collagen induced platelet aggregation (78 AU vs 37 AU; p=0.0001) and this difference was maintained at 14 days (80 AU vs 43 AU; p=0.0001). In patients, assigned to ticagrelor monotherapy after 1 month of DAPT, AA induced platelet aggregation progressively increased from day 0 to day 14. In the patients discontinuing ticagrelor and continuing on aspirin monotherapy, ADP induced platelet aggregation increased from day 0 to day 14. Rebound was seen in 6/17 (35%) patients in the ticagrelor monotherapy group versus 8/17 (47%) patients in the aspirin monotherapy group (p=0.728) with a mean peak of 21 AU (SD 6) and 10 AU (SD 6) respectively above baseline readings, p=0.003. There was no difference in TRAP induced aggregation at any time point. Figure 1 Conclusions Ticagrelor monotherapy was associated with higher collagen induced platelet aggregation than aspirin monotherapy at both 7 and 14 days post cessation of DAPT. Acknowledgement/Funding British Heart Foundation Project Grant PG/14/97/31263, AstraZeneca UK Limited

Recurrent Ischemic Lesions After Acute Atherothrombotic Stroke: Clopidogrel Plus Aspirin Versus Aspirin Alone.

In patients with acute ischemic stroke caused by large artery atherosclerosis, clopidogrel plus aspirin versus aspirin alone might be more effective to prevent recurrent cerebral ischemia. However, there is no clear evidence. In this multicenter, double-blind, placebo-controlled trial, we randomized 358 patients with acute ischemic stroke of presumed large artery atherosclerosis origin within 48 hours of onset to clopidogrel (75 mg/d without loading dose) plus aspirin (300-mg loading followed by 100 mg/d) or to aspirin alone (300-mg loading followed by 100 mg/d) for 30 days. The primary outcome was new symptomatic or asymptomatic ischemic lesion on magnetic resonance imaging within 30 days. Secondary outcomes were 30-day functional disability, clinical stroke recurrence, and composite of major vascular events. Safety outcome was any bleeding. Of 358 patients enrolled, 334 (167 in each group) completed follow-up magnetic resonance imaging. The 30-day new ischemic lesion recurrence rate was comparable between the clopidogrel plus aspirin and the aspirin monotherapy groups (36.5% versus 35.9%; relative risk, 1.02; 95% confidence interval, 0.77-1.35; P=0.91). Of the recurrent ischemic lesions, 94.2% were clinically asymptomatic. There were no differences in secondary outcomes between the 2 groups. Any bleeding were more frequent in the combination group than in the aspirin monotherapy group, but the difference was not significant (16.7% versus 10.7%; P=0.11). One hemorrhagic stroke occurred in the clopidogrel plus aspirin group. Clopidogrel plus aspirin might not be superior to aspirin alone for preventing new ischemic lesion and clinical vascular events in patients with acute ischemic stroke caused by large artery atherosclerosis. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00814268.

Impact of Dual Antiplatelet Therapy on Outcomes Among Aspirin-Resistant Patients Following Coronary Artery Bypass Grafting

Coronary artery bypass grafting is pivotal in the contemporary management of complex coronary artery disease. Interpatient variability to antiplatelet agents, however, harbors the potential to compromise the revascularization benefit by increasing the incidence of adverse events. This study was designed to define the impact of dual antiplatelet therapy (dAPT) on clinical outcomes among aspirin-resistant patients who underwent coronary artery surgery. We randomly assigned 219 aspirin-resistant patients according to multiple electrode aggregometry to receive clopidogrel (75 mg) plus aspirin (300 mg) or aspirin-monotherapy (300 mg). The primary end point was a composite outcome of all-cause death, nonfatal myocardial infarction, stroke, or cardiovascular hospitalization assessed at 6 months postoperatively. The primary end point occurred in 6% of patients assigned to dAPT and 10% of patients randomized to aspirin-monotherapy (relative risk 0.61, 95% confidence interval 0.25 to 1.51, p = 0.33). No significant treatment effect was noted in the occurrence of the safety end point. The total incidence of bleeding events was 25% and 19% in the dAPT and aspirin-monotherapy groups, respectively (relative risk 1.34, 95% confidence interval 0.80 to 2.23, p = 0.33). In the subgroup analysis, dAPT led to lower rates of adverse events in patients with a body mass index >30 kg/m(2) (0% vs 18%, p <0.01) and those <65 years (0% vs 10%, p = 0.02). In conclusion, the addition of clopidogrel in patients found to be aspirin resistant after coronary artery bypass grafting did not reduce the incidence of adverse events, nor did it increase the number of recorded bleeding events. dAPT did, however, lower the incidence of the primary end point in obese patients and those <65 years.

Single versus Dual Antiplatelet Therapy after CABG Surgery

Background: The optimal antiplatelet therapy regimen in the early post-operative CABG period is not well researched. Several studies have proven that use of clopidogrel and aspirin prior to surgery increases bleed risks, but very few studies have examined this therapy post-operatively. Due to the limited amount of data surrounding this topic, the goal of this study was to determine if single or dual antiplatelet therapy had better outcomes in those status-post CABG surgery. Methods: This was a retrospective, single center, cohort study performed at Saint Joseph Hospital in Lexington, Kentucky. Data was reviewed through the Society of Thoracic Surgeons (STS) database, pharmacy medication dispensing records, as well as manual chart review. The primary composite endpoint of the study consisted of in-hospital mortality, ischemic or thrombotic events, bleeding events, restenosis rates, and 30-day readmission rates. Results: The number of events with regard to the primary composite endpoint was 32 events with combination therapy and 39 events with aspirin monotherapy (p = 0.39). A greater decrease in hemoglobin and hematocrit was seen in the aspirin monotherapy group (p = 0.02 and p = 0.047). Patients with prior CVA or TIA were more commonly placed on combination therapy after surgery (p = 0.018). There were no differences in outcomes when type of antiplatelet therapy and type of CABG were analyzed. Conclusions: There was no difference seen between single versus dual antiplatelet therapy regarding the primary composite endpoint. There was an increase in bleeding events with aspirin monotherapy as defined by TIMI criteria as well as a statistically significant decrease in Hgb and HCT with aspirin monotherapy. Patients with previous CVA/TIA were more likely to receive combination therapy. The average number of vessels grafted per surgery was lower in the off-pump surgery cohort.

CHARISMA Revisited: Is the Glass Half Full or Just Empty?

The landmark CHARISMA study attempted to show that combination therapy with aspirin plus clopidogrel was superior to aspirin alone in a mixed population of patients with known vascular disease or those with risk factors for vascular disease. Although the study was negative for the combined group, a re-analysis of the outcomes and event rates showed striking differences between the two major patient types. Whereas individuals with risk factors only did not benefit from combination therapy, those with symptomatic vascular disease had a statistically significant 12% relative risk reduction in stroke/MI/vascular death with combination therapy vs aspirin alone. This dichotomous result was due largely to different event rates for the aspirin monotherapy group, being much higher in the symptomatic population compared to the risk factor group. Severe bleeding was not increased significantly for the symptomatic patients taking combination therapy vs aspirin alone. Based on these analyses, it may be premature to abandon combination therapy in a high-risk symptomatic population, especially since aspirin alone appears to have a high failure rate.

Effects of atorvastatin and aspirin combined therapy on inflammatory responses in patients undergoing coronary artery bypass grafting

This study was conducted to compare the effects of atorvastatin plus aspirin combined therapy on inflammatory responses, endothelial cell function, and blood coagulation system in patients undergoing coronary artery bypass grafting (CABG) to aspirin monotherapy. The patients were randomized into atorvastatin plus aspirin combined therapy group and aspirin monotherapy group. Reduced total cholesterol in the combined therapy group was found in a short term of medication for 14 days. On postoperative day (POD)-14, inhibitory effects of the combined therapy on whole blood aggregation as well as platelet activation assessed by flow cytometry were stronger than those of the monotherapy. Furthermore, cytokine, cytokine receptors, c-reactive protein and α1-acid glycoprotein in the combined therapy group were down-regulated on POD-14. At the same time, circulating levels of thromboxane A 2, vascular endothelial growth factor and thrombin–antithrombin III complex as well as P-selectin, L-selectin and intercellular adhesion molecule-1 were down-regulated, while E-selectin and transforming growth factor-β1 was up-regulated. Atorvastatin plus aspirin combined therapy may improve inflammatory responses, accelerated platelet function, vascular endothelial cell function, blood coagulation system at the early stage such as 14th day after CABG. In conclusion, atorvastatin and aspirin combined therapy may bring beneficial effects to the patient after CABG.