Inflammation and platelet reactivity during adjunctive colchicine versus aspirin in patients with acute coronary syndrome treated with potent P2Y12 inhibitor.

Background: In patients undergoing percutaneous coronary intervention (PCI), the use of anti-inflammatory therapy with colchicine is associated with a reduction of recurrent ischemic events. The mechanisms of such findings are not fully elucidated. Objectives: To investigate the effects of colchicine versus aspirin on inflammation and platelet reactivity in patients with acute coronary syndrome (ACS) undergoing PCI. Methods: This observational study compared laboratory measurements in ACS patients receiving single antiplatelet therapy with ticagrelor or prasugrel plus colchicine (MACT) (n = 185) versus conventional dual-antiplatelet therapy (DAPT) with aspirin plus ticagrelor or prasugrel (n = 497). The primary outcome was the frequency of high residual inflammation, defined as high-sensitivity C-reactive protein (hs-CRP) ≥2 mg/L at 1 month post-PCI. Multiple sensitivity analyses were performed for the primary outcome, including multivariable adjustment, propensity-score matching, and inverse-probability weighted methods. Results: One month after PCI, patients treated with MACT had significantly lower levels of hs-CRP compared to those treated with DAPT (0.6 [0.4-1.2] vs. 0.9 [0.6-2.3] mg/L, p < 0.001). The frequency of high residual inflammation was also lower in the MACT group (10.8% vs. 27.2%, p < 0.001) (odds ratio [95% confidence interval] = 0.33 [0.20-0.54], p < 0.001). This effect was consistent across sensitivity analyses. There was no difference in platelet reactivity between MACT and DAPT (49.6 ± 49.0 vs. 51.5 ± 66.4 P2Y12 reaction unit [PRU] measured by VerifyNow, p = 0.776). Conclusion: In ACS patients undergoing PCI, MACT was associated with a lower rate of high residual inflammation without increasing platelet reactivity compared to conventional DAPT. Clinical trial registration: NCT04949516 for MACT pilot trial and NCT04650529 for Gyeongsang National University Hospital registry.

Impaired endogenous fibrinolysis status: a potential prognostic predictor in ischemic stroke.

Stroke confers a severe global healthcare burden, hence exploring risk factors for stroke occurrence and prognosis is important for stroke prevention and post-stroke management strategies. Endogenous fibrinolysis is a spontaneous physiological protective mechanism that dissolves thrombus to maintain vascular patency. Recently, impaired endogenous fibrinolysis has been considered as a potential novel cardiovascular risk factor, but its link with ischaemic stroke in the past has been underappreciated. In this review, we summarize the latest mechanisms of endogenous fibrinolysis, review the current evidence and data on endogenous fibrinolysis in ischemic stroke. It includes the structure of thrombus in ischemic stroke patients, the effect of fibrin structure on the endogenous fibrinolytic efficiency, and the association between intravenous thrombolytic therapy and endogenous fibrinolysis in ischemic stroke. It also includes the single factors (tissue plasminogen activator, urokinase plasminogen activator, plasminogen activator inhibitor-1, thrombin activatable fibrinolysis inhibitor, complement component 3, complement component 5, alpha-2-antiplasmin, plasmin-alpha-2-antiplasmin complex, and lipoprotein[a]), and the global assessments of endogenous fibrinolysis status (thromboelastography, rotational thromboelastometry, and global thrombosis test), and their potential as predictors to identify occurrence or unfavorable functional outcomes of ischemic stroke. All of these assessments present advantages and limitations, and we suggest that the global thrombosis test may be more appropriate for detecting impaired endogenous fibrinolysis status in ischemic stroke patients.

Efficacy and Safety of P2Y12 monotherapy vs standard DAPT in patients undergoing percutaneous coronary intervention: meta-analysis of randomized trials.

BACKGROUND: Debates persist regarding the optimal duration of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) in coronary artery disease (CAD). Recent trials have introduced a novel approach involving P2Y12 inhibitor monotherapy with ticagrelor or clopidogrel, after a short DAPT. However, the effectiveness and safety of this strategy remains to be established. We aimed to perform a meta-analysis comparing monotherapy with P2Y12 inhibitors versus standard DAPT in patients undergoing PCI at 12 months. METHODS: Multiple databases were searched. Six RCTs with a total of 24877 patients were included. The primary endpoint was all-cause mortality at 12 months of follow-up. The secondary endpoints were cardiovascular mortality, myocardial infarction, probable or definite stent thrombosis, stroke events, and major bleeding. The study is registered with PROSPERO (CRD42024499529). RESULTS: Monotherapy with P2Y12 inhibitor ticagrelor significantly reduced both allcause mortality (HR 0.71, 95 CI [0.55-0.91], P = 0.007) and cardiovascular mortality (HR 0.66, 95% CI [0.49-0.89], P = 0.006) compared to standard DAPT. In contrast, clopidogrel monotherapy did not demonstrate a similar reduction. The decrease in mortality associated with ticagrelor was primarily due to a lower risk of major bleeding (HR 0.56, 95% CI [0.43-0.72], P < 0.001), while the risk of myocardial infarction (MI) remained unchanged (HR 0.90, 95% CI [0.73-1.11], P = 0.32). The risk of stroke was found to be similar across treatments. CONCLUSIONS: In comparison to standard DAPT, P2Y12 inhibitor monotherapy with ticagrelor may lead to a reduced mortality. The clinical benefits are driven by a reduction of bleeding risk without ischemic risk trade-off.

Impact of very low dose rivaroxaban in addition to dual antiplatelet therapy on endogenous fibrinolysis in acute coronary syndrome: The VaLiDate-R study.

BACKGROUND: Impaired endogenous fibrinolysis is adverse cardiovascular risk factor in acute coronary syndrome (ACS) patients. Addition of very low dose rivaroxaban (VLDR) to dual antiplatelet therapy (DAPT) reduces cardiovascular events but increases bleeding. OBJECTIVE: We aimed to assess whether addition of VLDR to DAPT can enhance endogenous fibrinolysis. METHODS: In a prospective, open-label trial, we assessed endogenous fibrinolysis in whole blood, in 549 patients with ACS using the Global Thrombosis Test (GTT) and Thromboelastography (TEG). Patients (n = 180) who demonstrated impaired endogenous fibrinolysis (lysis time [LT] >2000s with the GTT) were randomised 1:1:1 to (i) clopidogrel 75 mg daily; (ii) clopidogrel 75 mg daily plus rivaroxaban 2.5 mg twice daily; or (iii) ticagrelor 90 mg twice daily, for 30 days, in addition to aspirin. Fibrinolytic status was assessed at 0, 2, 4 and 8 weeks. The primary outcome was the change in LT from admission to week 4. We also measured thrombotic occlusion time (OT) at high shear, and rivaroxaban level. RESULTS: There was no difference between the groups with respect to LT or clot lysis with TEG, and no change in these parameters compared to baseline during study drug allocation. In the rivaroxaban plus clopidogrel group, OT was prolonged compared to the other groups, although rivaroxaban levels were low, suggesting non-compliance. CONCLUSION: Addition of rivaroxaban 2.5 mg twice daily to DAPT does not affect endogenous fibrinolysis of thrombus formed at either high or low shear. Further studies are needed to determine whether higher doses of rivaroxaban can favourably modulate fibrinolysis. CONDENSED ABSTRACT: Impaired endogenous fibrinolysis is a strong risk factor in ACS. We aimed to assess whether adding very low dose rivaroxaban (VLDR) to DAPT can enhance fibrinolysis. Fibrin and clot lysis were assessed in whole blood. ACS patients with impaired fibrinolysis were randomised 1:1:1 to clopidogrel 75 mg daily; clopidogrel 75 mg plus VLDR; or ticagrelor 90 mg twice daily, in addition to aspirin. At 30-days, there was no difference in lysis time between the groups, nor change from baseline. VLDR does not improve fibrinolysis at high or low shear. Further studies are needed to determine whether alternative antithrombotic regimens can enhance endogenous fibrinolysis.

Spontaneous reperfusion in STEMI: Its mechanisms and possible modulation.

Patients with transient ST-segment elevation myocardial infarction or spontaneous reperfusion, which occurs in approximately 20% of patients with ST-segment elevation myocardial infarction (STEMI), have smaller infarcts and more favorable clinical outcomes than patients without spontaneous reperfusion. Understanding the mechanisms underlying spontaneous reperfusion is therefore important since this may identify possible novel therapeutic targets to improve outcomes in patients with STEMI. In this review, we discuss some of the possible determinants of spontaneous reperfusion including pro-thrombotic profile, endogenous fibrinolytic status, lipoprotein(a) (Lp[a]), inflammatory markers, and neutrophil extracellular traps (NETs). Effective (rapid) endogenous fibrinolysis, as assessed in whole blood in vitro, using a point-of-care technique assessment of global thrombotic status, has been strongly linked to spontaneous reperfusion. Lp(a), which has a high degree of homology to plasminogen, may impair fibrinolysis through competitive inhibition of tissue plasminogen activator-mediated plasminogen activation as well as tissue plasminogen activator-mediated clot lysis and contribute to pathogenic clot properties by decreasing fibrin clot permeation. NETs appear to negatively modulate clot lysis by increasing thrombin fiber diameter and inhibiting plasmin-driven lysis of plasma clots. There are limited data that oral anticoagulation may modulate endogenous fibrinolysis but antiplatelet agents currently appear to have no impact. Phase III trials involving subcutaneous P2Y12 or glycoprotein IIb/IIIa inhibitors, oral factor XIa inhibitors, interleukin-6 inhibitors, and apolipoprotein(a) antisense oligonucleotides in patients with cardiovascular disease are ongoing. Future studies will be needed to determine the impact of these novel antithrombotic, anti-inflammatory, and lipid-lowering therapies on endogenous fibrinolysis and spontaneous reperfusion.

Ethnic Differences in Thrombotic Profiles of Acute Coronary Syndrome Patients and Relationship to Cardiovascular Outcomes: A Comparison of East Asian and White subjects.

BACKGROUND: East Asians (EAs), compared to white Caucasians (W), have a lower risk of ischemic heart disease and a higher risk of bleeding with antithrombotic medications. The underlying mechanisms are incompletely understood. OBJECTIVES: We sought to compare thrombotic profiles of EA and W patients with myocardial infarction (MI) and relate these to cardiovascular outcomes. METHODS: In a prospective study in the United Kingdom and Korea, blood samples from patients (n = 515) with ST- or non-ST-elevation MI (STEMI and NSTEMI) were assessed using the Global Thrombosis Test, measuring thrombotic occlusion (OT) and endogenous fibrinolysis (lysis time [LT]). Patients were followed for 1 year for major adverse cardiovascular events (MACE) and bleeding. RESULTS: EA patients showed reduced OT (longer OT) compared to W (646 seconds [470-818] vs. 436 seconds [320-580], p < 0.001), with similar LT. In STEMI, OT (588 seconds [440-759] vs. 361 seconds [274-462], p < 0.001) and LT (1,854 seconds [1,389-2,729] vs. 1,338 seconds [1,104-1,788], p < 0.001) were longer in EA than W. In NSTEMI, OT was longer (OT: 734 seconds [541-866] vs. 580 seconds [474-712], p < 0.001) and LT shorter (1519 seconds [1,058-2,508] vs. 1,898 seconds [1,614-2,806], p = 0.004) in EA than W patients. MACE was more frequent in W than EA (6.3 vs. 1.9%, p = 0.014) and bleeding infrequent. While OT was unrelated, LT was a strong independent predictor of MACE event after adjustment for risk factors (hazard ratio: 3.70, 95% confidence interval: 1.43-9.57, p = 0.007), predominantly in W patients, and more so in STEMI than NSTEMI patients. CONCLUSION: EA patients exhibit different global thrombotic profiles to W, associated with a lower rate of cardiovascular events.

Low-Dose Aspirin for Primary Prevention of Cardiovascular Events Comparing East Asians With Westerners: A Meta-Analysis.

Background: East Asians have shown different risk profiles for both thrombophilia and bleeding than Western counterparts. Objectives: The authors sought to evaluate the effect of low-dose aspirin for primary prevention between these populations. Methods: We searched randomized clinical trials (RCTs) for intervention with low-dose aspirin (≤100 mg once daily) in participants without symptomatic cardiovascular disease until December 31, 2021. The number of events between the arms was extracted for analysis. Pooled risk ratios (RRs) and risk differences (RDs) were analyzed in each population. Outcomes included a major adverse cardiovascular event (MACE), cardiovascular death, myocardial infarction, stroke, and major bleeding (intracranial hemorrhage and major gastrointestinal bleeding). Results: Two RCTs included 17,003 East Asians, and 9 RCTs had 117,467 Western participants. Aspirin treatment showed a similar effect in reducing the MACE rate (RR of East Asians: 0.87; 95% CI: 0.71-1.05; RR of Westerners: 0.90; 95% CI: 0.85-0.95) (Pinteraction = 0.721). In contrast, the risk of major bleeding during aspirin vs control was greater in the East Asian population (RR: 2.48; 95% CI: 1.86-3.30) compared with the Western population (RR: 1.45; 95% CI: 1.26-1.66) (Pinteraction = 0.001), which was driven by more frequent gastrointestinal bleeding (RR of East Asians: 3.29; 95% CI: 2.26-4.80 vs RR of Westerners: 1.56; 95% CI: 1.29-1.88) (Pinteraction < 0.001). The net RDs (RD of MACE plus RD of major bleeding) were 8.04 and 0.72 per 1,000 persons in East Asian and Western participants, indicating 124 and 1,389 of the net number needed to harm, respectively. Conclusions: Low-dose aspirin for primary prevention in East Asians must be cautiously prescribed because of the increased risk of major bleeding relative to Western counterparts.