Higher risk of ischaemic stroke associated with factor XI levels in dyslipidaemic patients

Factor XIa inhibition with asundexian after acute non-cardioembolic ischaemic stroke (PACIFIC-Stroke): an international, randomised, double-blind, placebo-controlled, phase 2b trial

BACKGROUND

Asundexian (Bayer AG, Leverkusen, Germany), an oral small molecule factor XIa (FXIa) inhibitor, might prevent thrombosis without increasing bleeding. Asundexian's effect for secondary prevention of recurrent stroke is unknown.

METHODS

In this randomised, double-blind, placebo-controlled, phase 2b dose-finding trial (PACIFIC-Stroke), patients with acute (within 48 h) non-cardioembolic ischaemic stroke were recruited from 196 hospitals in 23 countries. Patients were eligible if they were aged 45 years or older, to be treated with antiplatelet therapy, and able to have a baseline MRI (either before or within 72 h of randomisation). Eligible participants were randomly assigned (1:1:1:1), using an interactive web-based response system and stratified according to anticipated antiplatelet therapy (single vs dual), to once daily oral asundexian (BAY 2433334) 10 mg, 20 mg, or 50 mg, or placebo in addition to usual antiplatelet therapy, and were followed up during treatment for 26-52 weeks. Brain MRIs were obtained at study entry and at 26 weeks or as soon as possible after treatment discontinuation. The primary efficacy outcome was the dose-response effect on the composite of incident MRI-detected covert brain infarcts and recurrent symptomatic ischaemic stroke at or before 26 weeks after randomisation. The primary safety outcome was major or clinically relevant non-major bleeding as defined by International Society on Thrombosis and Haemostasis criteria. The efficacy outcome was assessed in all participants assigned to treatment, and the safety outcome was assessed in all participants who received at least one dose of study treatment. This study is registered with ClinicalTrials.gov, NCT04304508, and is now complete.

FINDINGS

Between June 15, 2020, and July 22, 2021, 1880 patients were screened and 1808 participants were randomly assigned to asundexian 10 mg (n=455), 20 mg (n=450), or 50 mg (n=447), or placebo (n=456). Mean age was 67 years (SD 10) and 615 (34%) participants were women, 1193 (66%) were men, 1505 (83%) were White, and 268 (15%) were Asian. The mean time from index stroke to randomisation was 36 h (SD 10) and median baseline National Institutes of Health Stroke Scale score was 2·0 (IQR 1·0-4·0). 783 (43%) participants received dual antiplatelet treatment for a mean duration of 70·1 days (SD 113·4) after randomisation. At 26 weeks, the primary efficacy outcome was observed in 87 (19%) of 456 participants in the placebo group versus 86 (19%) of 455 in the asundexian 10 mg group (crude incidence ratio 0·99 [90% CI 0·79-1·24]), 99 (22%) of 450 in the asundexian 20 mg group (1·15 [0·93-1·43]), and 90 (20%) of 447 in the asundexian 50 mg group (1·06 [0·85-1·32]; t statistic -0·68; p=0·80). The primary safety outcome was observed in 11 (2%) of 452 participants in the placebo group versus 19 (4%) of 445 in the asundexian 10 mg group, 14 (3%) of 446 in the asundexian 20 mg group, and 19 (4%) of 443 in the asundexian 50 mg group (all asundexian doses pooled vs placebo hazard ratio 1·57 [90% CI 0·91-2·71]).

INTERPRETATION

In this phase 2b trial, FXIa inhibition with asundexian did not reduce the composite of covert brain infarction or ischaemic stroke and did not increase the composite of major or clinically relevant non-major bleeding compared with placebo in patients with acute, non-cardioembolic ischaemic stroke.

FUNDING

Bayer AG.

Sex Differences in Hemostatic Factors in Patients With Ischemic Stroke and the Relation With Migraine-A Systematic Review

Background: Women are more affected by stroke than men. This might, in part, be explained by sex differences in stroke pathophysiology. The hemostasis system is influenced by sex hormones and associated with female risk factors for stroke, such as migraine.

Aim: To systematically review possible sex differences in hemostatic related factors in patients with ischemic stroke in general, and the influence of migraine on these factors in women with ischemic stroke.

Results: We included 24 studies with data on sex differences of hemostatic factors in 7247 patients with ischemic stroke (mean age 57–72 years, 27–57% women) and 25 hemostatic related factors. Levels of several factors were higher in women compared with men; FVII:C (116% ± 30% vs. 104% ± 30%), FXI (0.14 UI/mL higher in women), PAI-1 (125.35 ± 49.37 vs. 96.67 ± 38.90 ng/mL), D-dimer (1.25 ± 0.31 vs. 0.95 ± 0.24 μg/mL), and aPS (18.7% vs. 12.0% positive). In contrast, protein-S (86.2% ± 23.0% vs. 104.7% ± 19.8% antigen) and P-selectin (48.9 ± 14.4 vs. 79.1 ± 66.7 pg/mL) were higher in men. Most factors were investigated in single studies, at different time points after stroke, and in different stroke subtypes. Only one small study reported data on migraine and hemostatic factors in women with ischemic stroke. No differences in fibrinogen, D-dimer, t-PA, and PAI-1 levels were found between women with and without migraine.

Conclusion: Our systematic review suggests that sex differences exist in the activation of the hemostatic system in ischemic stroke. Women seem to lean more toward increased levels of procoagulant factors whereas men exhibit increased levels of coagulation inhibitors. To obtain better insight in sex-related differences in hemostatic factors, additional studies are needed to confirm these findings with special attention for different stroke phases, stroke subtypes, and not in the least women specific risk factors, such as migraine.

Associations of coagulation factor X and XI with incident acute coronary syndrome and stroke: A nested case-control study

BACKGROUND

Coagulation cascade contributes to thrombotic and hemorrhagic diseases, but it remains unclear whether coagulation factors X (FX) and XI (FXI) levels are associated with cardiovascular diseases.

OBJECTIVE

To evaluate prospective associations of FX and FXI levels with incident acute coronary syndrome (ACS), stroke, and their subtypes (acute myocardial infarction, unstable angina, ischemic stroke, and hemorrhagic stroke).

METHODS

We performed a nested case-control study (n = 1846) within the Dongfeng-Tongji cohort from 2013 to 2016 matched on age (within 1 year), sex, and sampling date (within 1 month) by incidence density sampling, and measured plasma FX and FXI levels by enzyme-linked immunosorbent assay. FX and FXI levels were categorized into three groups (low, <25th; middle, 25th to <75th; and high ≥75th percentiles) according to distributions, and conditional logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

After adjustment for traditional cardiovascular risk factors, compared with middle groups, the OR (95% CI) in high levels of FX and FXI were 1.11 (0.79-1.56) and 0.96 (0.68-1.36) for incident ACS, and 1.01 (0.63-1.62) and 1.72 (1.14-2.60) for incident stroke, respectively. As for subtypes of ACS and stroke, only high FXI levels were significantly associated with incident ischemic stroke (OR 1.66, 95% CI 1.05-2.65). Moreover, all associations remained steady after additional adjustment for platelet and leukocyte.

CONCLUSION

FXI levels were associated with a greater risk of incident ischemic stroke but not hemorrhagic stroke or ACS. FX levels were not associated with incident ACS or stroke.

Associations of coagulation factors IX and XI levels with incident coronary heart disease and ischemic stroke: the REGARDS study

Essentials Coagulation factors (F) IX and XI have been implicated in cardiovascular disease (CVD) risk. We studied associations of FIX and FXI with incident coronary heart disease (CHD) and stroke. Higher FIX antigen was associated with incident CHD risk in blacks but not whites. Higher levels of FIX antigen may be a CHD risk factor among blacks.

SUMMARY

Background Recent studies have suggested the importance of coagulation factor IX and FXI in cardiovascular disease (CVD) risk. Objectives To determine whether basal levels of FIX or FXI antigen were associated with the risk of incident coronary heart disease (CHD) or ischemic stroke. Patients/Methods The REasons for Geographic And Racial Differences in Stroke (REGARDS) study recruited 30 239 participants across the contiguous USA between 2003 and 2007. In a case-cohort study within REGARDS, FIX and FXI antigen were measured in participants with incident CHD (n = 609), in participants with incident ischemic stroke (n = 538), and in a cohort random sample (n = 1038). Hazard ratios (HRs) for CHD and ischemic stroke risk were estimated with Cox models per standard deviation higher FIX or FXI level, adjusted for CVD risk factors. Results In models adjusting for CHD risk factors, higher FIX levels were associated with incident CHD risk (HR 1.19; 95% confidence interval [CI] 1.01-1.40) and the relationship of higher FXI levels was slightly weaker (HR 1.15; 95% CI 0.97-1.36). When stratified by race, the HR of FIX was higher in blacks (HR 1.39; 95% CI 1.10-1.75) than in whites (HR 1.06; 95% CI 0.86-1.31). After adjustment for stroke risk factors, there was no longer an association of FIX levels with ischemic stroke, whereas the association of FXI levels with ischemic stroke was slightly attenuated. Conclusions Higher FIX antigen levels were associated with incident CHD in blacks but not in whites. FIX levels may increase CHD risk among blacks.

Active tissue factor and activated factor XI in patients with acute ischemic cerebrovascular events

BACKGROUND

  Elevated factor (F)XI and tissue factor (TF) have been reported to occur in patients with acute ischemic stroke (AIS). We sought to investigate whether circulating activated FXI (FXIa) and TF on admission can predict clinical outcomes in patients with acute cerebrovascular events.

MATERIALS AND METHODS

  In the observational study, we evaluated 205 consecutive patients aged 70 years or less within the first 72 h of acute event, including 140 with AIS and 65 with transient ischemic attack (TIA). Plasma TF and FXIa activity were determined on admission in clotting assays by measuring the response to inhibitory monoclonal antibodies.

RESULTS

Active TF and FXIa activity were detected in 58 (28·9%) and 132 (64·4%) patients on admission, respectively. Active TF was detected in 45 of the 136 AIS patients with available TF levels (33·1%) and 13 of the 65 patients with acute TIA (20%; 0·05). Corresponding values for FXIa were 99 of the 140 (70·7%) and 33 of the 65 (50·8%; P= 0·006), respectively. Patients with detectable TF were more frequently women and hypertensive, while subjects with detectable FXIa had more often diabetes and higher levels of fibrinogen, C-reactive protein and interleukin-6 (all P < 0·05). Patients with detectable FXIa but not TF had higher National Institutes of Health Stroke Scale score, higher modified Rankin scale score and lower Barthel Index at discharge (all P < 0·05).

CONCLUSIONS

Circulating active TF and FXIa occur frequently in acute cerebrovascular ischemic events. Active FXIa in plasma might be useful as a novel risk marker of worse functional outcomes in patients with acute cerebrovascular events.

Circulating activated factor XI and active tissue factor as predictors of worse prognosis in patients following ischemic cerebrovascular events

BACKGROUND

Elevated factor (F)XI is associated with an increased risk for ischemic stroke. Activated FXI (FXIa) and tissue factor (TF) have not been studied following stroke. The aim of the current study was to evaluate circulating FXIa and TF in patients with prior cerebrovascular events.

PATIENTS/METHODS

We studied 241 patients, including 162 after ischemic stroke and 79 after transient ischemic attack (TIA), recruited 6 months to 4 years (median, 36 months) after the events. Plasma TF and FXIa activity following the index event were determined in clotting assays by measuring the response to inhibitory monoclonal antibodies.

RESULTS

Active TF was detected in 25 (10.4%) of the patients, while FXIa activity (median, 37.5 [IQR 397] pM) was found in 64 (26.7%) of the patients (p<0.01). The prevalence of active TF and FXIa was higher in subjects with previous stroke compared with those with a history of TIA (13% vs 5.1%, p=0.05, and 34% vs 11.4%, p<0.0001, respectively). Patients with circulating FXIa were younger and had higher fibrinogen and interleukin-6 compared to the remainder. Patients with detectable TF or FXIa activity had higher NIHSS score, higher modified Rankin scale and lower Barthel Index than the remaining subjects (all p<0.05).

CONCLUSION

Circulating active TF and FXIa can occur in patients with cerebrovascular ischemic events ≥6 months after the events. The presence of these factors is associated with worse functional outcomes, which highlights the role of persistent hypercoagulable state in cerebrovascular disease.

Novel hemostatic factor levels and risk of ischemic stroke: the Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND AND OBJECTIVE

The role of hemostatic factor levels in cerebral infarction remains uncertain. We studied the association of levels of several under-studied hemostatic factors with ischemic stroke in a population-based cohort.

METHODS

The Atherosclerosis Risk in Communities (ARIC) study includes 15,792 individuals aged 45-54 years at intake. Hemostatic factors II, V, IX, X, XI, XII, plasminogen and alpha(2)-antiplasmin were measured on frozen citrate plasma samples from 1990 to 1992. A case-cohort design was used, including all incident ischemic strokes (n = 89) over a median of 7.5 years and a stratified cohort random sample (n = 412). To determine the association of hemostatic factors with incident ischemic stroke, we computed hazard ratios (HRs) using multivariate proportional hazard regression analyses adjusted for demographic and other cardiovascular risk factors.

RESULTS

The cohort random sample had a mean age (SD) of 56.9 (5.4) years and 42% were men. The age-, sex- and race-adjusted HRs for highest versus lowest quartiles were: factor XI (2.74, 95% CI 1.42-5.29), factor IX (1.92, 95% CI 0.99-3.73), and alpha(2)-antiplasmin (2.24, 95% CI 1.16-4.33). Correspondingly, the HRs of ischemic stroke per SD increment of factors XI, IX, and alpha(2)-antiplasmin were 1.64, 1.46 and 1.52, respectively (all p < 0.05). After multivariate adjustment including other clinical variables, the standardized HR remained significant for factor XI (1.50, 95% CI 1.10-2.05), but no other factor.

CONCLUSION

A greater level of factor XI was associated with an increased risk of ischemic stroke. Higher factor XI levels might help identify patients at elevated ischemic stroke risk.