Heart Failure Risk Assessment Using Biomarkers in Patients With Atrial Fibrillation: Analysis From COMBINE-AF.

BACKGROUND: Heart failure (HF) is common among patients with atrial fibrillation (AF), and accurate risk assessment is clinically important. OBJECTIVES: The goal of this study was to investigate the incremental prognostic performance of N-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity cardiac troponin T (hs-cTnT), and growth differentiation factor (GDF)-15 for HF risk stratification in patients with AF. METHODS: Individual patient data from 3 large randomized trials comparing direct oral anticoagulants (DOACs) with warfarin (ARISTOTLE [Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation], ENGAGE AF-TIMI 48 [Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48], and RE-LY [Randomized Evaluation of Long-Term Anticoagulation Therapy]) from the COMBINE-AF (A Collaboration Between Multiple Institutions to Better Investigate Non-Vitamin K Antagonist Oral Anticoagulant Use in Atrial Fibrillation) cohort were pooled; all patients with available biomarkers at baseline were included. The composite endpoint was hospitalization for HF (HHF) or cardiovascular death (CVD), and secondary endpoints were HHF and HF-related death. Cox regression was used, adjusting for clinical factors, and interbiomarker correlation was addressed using weighted quantile sum regression analysis. RESULTS: In 32,041 patients, higher biomarker values were associated with a graded increase in absolute risk for CVD/HHF, HHF, and HF-related death. Adjusting for clinical variables and all biomarkers, NT-proBNP (HR per 1 SD: 1.68; 95% CI: 1.59-1.77), hs-cTnT (HR: 1.39; 95% CI: 1.33-1.44), and GDF-15 (HR: 1.20; 95% CI: 1.15-1.25) were significantly associated with CVD/HHF. The discrimination of the clinical model improved significantly upon addition of the biomarkers (c-index: 0.70 [95% CI: 0.69-0.71] to 0.77 [95% CI: 0.76-0.78]; likelihood ratio test, P < 0.001). Using weighted quantile sum regression analysis, the contribution to risk assessment was similar for NT-proBNP and hs-cTnT for CVD/HHF (38% and 41%, respectively); GDF-15 provided a statistically significant but lesser contribution to risk assessment. Results were similar for HHF and HF-related death, individually, and across key subgroups of patients based on history of HF, AF pattern, and reduced or preserved left ventricular ejection fraction. CONCLUSIONS: NT-proBNP, hs-cTnT, and GDF-15 contributed significantly and independently to the risk stratification for HF endpoints in patients with AF, with hs-cTnT being as important as NT-proBNP for HF risk stratification. Our findings support a possible future use of these biomarkers to distinguish patients with AF at low or high risk for HF.

Milvexian vs apixaban for stroke prevention in atrial fibrillation: The LIBREXIA atrial fibrillation trial rationale and design.

BACKGROUND: Direct oral anticoagulants are the standard of care for stroke prevention in eligible patients with atrial fibrillation and atrial flutter; however, bleeding remains a significant concern, limiting their use. Milvexian is an oral Factor XIa inhibitor that may offer similar anticoagulant efficacy with less bleeding risk. METHODS: LIBREXIA AF (NCT05757869) is a global phase III, randomized, double-blind, parallel-group, event-driven trial to compare milvexian with apixaban in participants with atrial fibrillation or atrial flutter. Participants are randomly assigned to milvexian 100 mg or apixaban (5 mg or 2.5 mg per label indication) twice daily. The primary efficacy objective is to evaluate if milvexian is noninferior to apixaban for the prevention of stroke and systemic embolism. The principal safety objective is to evaluate if milvexian is superior to apixaban in reducing the endpoint of International Society of Thrombosis and Hemostasis (ISTH) major bleeding events and the composite endpoint of ISTH major and clinically relevant nonmajor (CRNM) bleeding events. In total, 15,500 participants from approximately 1,000 sites in over 30 countries are planned to be enrolled. They will be followed until both 430 primary efficacy outcome events and 530 principal safety events are observed, which is estimated to take approximately 4 years. CONCLUSION: The LIBREXIA AF study will determine the efficacy and safety of the oral Factor XIa inhibitor milvexian compared with apixaban in participants with either atrial fibrillation or atrial flutter. TRIAL REGISTRATION: ClinicalTrials.gov NCT05757869.

Residual Stroke Risk Among Patients With Atrial Fibrillation Prescribed Oral Anticoagulants: A Patient-Level Meta-Analysis From COMBINE AF.

BACKGROUND: Despite oral anticoagulation, patients with atrial fibrillation (AF) remain at risk of ischemic stroke and systemic embolism (SE) events. For patients whose residual risk is sufficiently high, additional therapies might be useful to mitigate stroke risk. METHODS AND RESULTS: Individual patient data from 5 landmark trials testing oral anticoagulation in AF were pooled in A Collaboration Between Multiple Institutions to Better Investigate Non-Vitamin K Antagonist Oral Anticoagulant Use in AF (COMBINE AF). We calculated the rate of ischemic stroke/SE among oral anticoagulation-treated patients with a CHA2DS2-VASc score≥2, across strata of CHA2DS2-VASc score, stroke history, and AF type, as either paroxysmal or nonparoxysmal. We included 71 794 patients with AF (median age 72 years, interquartile range, 13 years, 61.3% male) randomized to a direct oral anticoagulant or vitamin K antagonist, and followed for a mean of 2.1 (±0.8) years. The median CHA2DS2-VASc score was 4 (interquartile range, 3-5), 18.8% had a prior stroke, and 76.4% had nonparoxysmal AF. The overall rate of stroke/SE was 1.33%/y (95% CI, 1.27-1.39); 1.38%/y (95% CI, 1.31-1.45) for nonparoxysmal AF, and 1.15%/y (95% CI, 1.05-1.27) for paroxysmal AF. The rate of ischemic stroke/SE increased by a rate ratio of 1.36 (95% CI, 1.32-1.41) per 1-point increase in CHA2DS2-VASc, reaching 1.67%/y (95% CI, 1.59-1.75) ≥4 CHA2DS2-VASc points. Patients with both nonparoxysmal AF and CHA2DS2-VASc ≥4 had a stroke/SE rate of 1.75%/y (95% CI, 1.66-1.85). In patients with a prior stroke, the risk was 2.51%/y (95% CI, 2.33-2.71). CONCLUSIONS: AF type, CHA2DS2-VASc score, and stroke history can identify patients with AF, who despite oral anticoagulation have a residual stroke/SE risk of 1.5% to 2.5% per year. Evaluation of additional stroke/SE prevention strategies in high-risk patients is warranted.

Clonal hematopoiesis, cardiovascular events and treatment benefit in 63,700 individuals from five TIMI randomized trials.

Clonal hematopoiesis of indeterminate potential (CHIP) has been associated with an increased risk of cardiovascular (CV) disease in the general population. Currently, it is unclear whether this association is observed in large clinical trial cohorts with a high burden of existing CV disease or whether CV therapies can mitigate CHIP-associated CV risk. To address these questions, we studied 63,700 patients from five randomized trials that tested established therapies for CV disease, including treatments targeting the proteins PCSK9, SGLT2, P2Y12 and FXa. During a median follow-up of 2.5 years, 7,453 patients had at least one CV event (CV death, myocardial infarction (MI), ischemic stroke or coronary revascularization). The adjusted hazard ratio (aHR) for CV events for CHIP+ patients was 1.07 (95% CI: 0.99-1.16, P = 0.08), with consistent risk estimates across each component of CV risk. Significant heterogeneity in the risk of MI was observed, such that CHIP+ patients had a 30% increased risk of first MI (aHR = 1.31 (1.05-1.64), P = 0.02) but no increased risk of recurrent MI (aHR = 0.94 (0.79-1.13), Pint = 0.008), as compared to CHIP- patients. Moreover, no significant heterogeneity in treatment effect between individuals with and without CHIP was observed for any of the therapies studied in the five trials. These results indicate that in clinical trial populations, CHIP is associated with incident but not recurrent coronary events and that the presence of CHIP does not appear to identify patients who will derive greater benefit from commonly used CV therapies.

Dose Reduction of Edoxaban in Patients 80 Years and Older With Atrial Fibrillation: Post Hoc Analysis of the ENGAGE AF-TIMI 48 Randomized Clinical Trial.

Importance: In older patients with atrial fibrillation who take anticoagulants for stroke prevention, bleeding is increased compared with younger patients, thus, clinicians frequently prescribe lower than recommended doses in older patients despite limited randomized data. Objective: To evaluate ischemic and bleeding outcomes in patients 80 years and older with atrial fibrillation receiving edoxaban, 60 mg vs 30 mg, and edoxaban, 30 mg vs warfarin. Design, Setting, and Participants: The ENGAGE AF-TIMI 48 trial (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48) was a parallel-design, double-blind, global clinical trial that randomized patients with atrial fibrillation to either one of 2 edoxaban dosing regimens or warfarin. This secondary analysis focused on patients 80 years or older without dose-reduction criteria receiving edoxaban, 60 mg vs 30 mg, as well as patients with or without dose-reduction criteria receiving edoxaban, 30 mg, vs warfarin. Study data were analyzed between October 2022 and December 2023. Interventions: Oral edoxaban, 30 mg once daily; edoxaban, 60 mg once daily; or warfarin. Main Outcomes and Measures: Primary net clinical outcome of death, stroke or systemic embolism, and major bleeding and each individual component. Results: The current analysis included 2966 patients 80 years and older (mean [SD] age, 83 [2.7] years; 1671 male [56%]). Among 1138 patients 80 years and older without dose-reduction criteria, those receiving edoxaban, 60 mg vs 30 mg, had more major bleeding events (hazard ratio [HR], 1.57; 95% CI, 1.04-2.38; P = .03), particularly gastrointestinal hemorrhage (HR, 2.24; 95% CI, 1.29-3.90; P = .004), with no significant difference in efficacy end points. Findings were supported by analyses of endogenous factor Xa inhibition, a marker of anticoagulant effect, which was comparable between younger patients receiving edoxaban, 60 mg, and older patients receiving edoxaban, 30 mg. In 2406 patients 80 years and older with or without dose-reduction criteria, patients receiving edoxaban, 30 mg, vs warfarin had lower rates of the primary net clinical outcome (HR, 0.78; 95% CI, 0.68-0.91; P = .001), major bleeding (HR, 0.59; 95% CI, 0.45-0.77; P < .001), and death (HR, 0.83; 95% CI, 0.70-1.00; P = .046), whereas rates of stroke or systemic embolism were comparable. Conclusions and Relevance: In this post hoc analysis of the ENGAGE AF-TIMI 48 randomized clinical trial, in patients 80 years and older with atrial fibrillation, major bleeding events were lower in patients randomized to receive edoxaban, 30 mg per day, compared with either edoxaban, 60 mg per day (in patients without dose-reduction criteria), or warfarin (irrespective of dose-reduction status), without an offsetting increase in ischemic events. These data support the concept that lower-dose anticoagulants, such as edoxaban, 30 mg, may be considered in older patients with atrial fibrillation even in the absence of dose-reduction criteria. Trial Registration: ClinicalTrials.gov Identifier: NCT00781391.

Will Factor XI Inhibitors Replace Current Anticoagulants for Stroke Prevention in Atrial Fibrillation?

PURPOSE OF REVIEW: This review provides an overview of the factor XI (FXI) inhibitor hypothesis for the development of novel anticoagulants which may be safer to those currently used in clinical practice and describes preliminary clinical data from phase 2 dose-ranging studies of patients with atrial fibrillation. RECENT FINDINGS: Recent data from phase 2 dose ranging studies demonstrate substantial reductions in bleeding with FXI pathway inhibition compared with currently approved anticoagulants. However, larger studies are necessary to demonstrate efficacy of FXI inhibition for stroke prevention in atrial fibrillation. FXI pathway inhibition holds great promise for revolutionizing the landscape of anticoagulation for atrial fibrillation, primarily by reducing bleeding risk; however, further data are necessary to demonstrate efficacy.

Application of the Win Ratio Method in the ENGAGE AF-TIMI 48 Trial Comparing Edoxaban With Warfarin in Patients With Atrial Fibrillation.

BACKGROUND: Cardiovascular trials often use a composite end point and a time-to-first event model. We sought to compare edoxaban versus warfarin using the win ratio, which offers data complementary to time-to-first event analysis, emphasizing the most severe clinical events. METHODS: ENGAGE AF-TIMI 48 (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48) was a double-blind, randomized trial in which patients with atrial fibrillation were assigned 1:1:1 to a higher dose edoxaban regimen (60/30 mg daily), a lower dose edoxaban regimen (30/15 mg daily), or warfarin. In an exploratory analysis, we analyzed the trial outcomes using an unmatched win ratio approach. The win ratio for each edoxaban regimen was the total number of edoxaban wins divided by the number of warfarin wins for the following ranked clinical outcomes: 1: death; 2: hemorrhagic stroke; 3: ischemic stroke/systemic embolic event/epidural or subdural bleeding; 4: noncerebral International Society on Thrombosis and Haemostasis major bleeding; and 5: cardiovascular hospitalization. RESULTS: 21 105 patients were randomized to higher dose edoxaban regimen (N=7035), lower dose edoxaban regimen (N=7034), or warfarin (N=7046), yielding >49 million pairs for each treatment comparison. The median age was 72 years, 38% were women, and 59% had prior vitamin K antagonist use. The win ratio was 1.11 (95% CI, 1.05-1.18) for higher dose edoxaban regimen versus warfarin and 1.11 (95% CI, 1.05-1.18) for lower dose edoxaban regimen versus warfarin. The favorable impacts of edoxaban on death (34% of wins) and cardiovascular hospitalization (41% of wins) were the major contributors to the win ratio. Results consistently favored edoxaban in subgroups based on creatine clearance and dose reduction at baseline, with heightened benefit among those without prior vitamin K antagonist use. CONCLUSIONS: In a win ratio analysis of the ENGAGE AF-TIMI 48 trial, both dose regimens of edoxaban were superior to warfarin for the net clinical outcome incorporating ischemic and bleeding events. As the win ratio emphasizes the most severe clinical events, this analysis supports the superiority of edoxaban over warfarin in patients with atrial fibrillation. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT00781391.

Effects of newer anti-hyperglycemic agents on cardiovascular outcomes in older adults: Systematic review and meta-analysis.

AIM: To demonstrate cardiovascular safety of dipeptidyl peptidase-4 inhibitors (DPP-4i), glucagon-like peptide-1 receptor agonists (GLP-1RA), and sodium/glucose cotransporter 2 inhibitors (SGLT-2i) across age-groups. METHODS: PubMed, Embase and Cochrane were searched for cardiovascular outcome trials (CVOTs) testing newer agents until August 31, 2022 (PROSPERO ID CRD42021260167). Studies with ≥1000 T2D participants enrolled for ≥12 months were included. Random effect models were used to report relative-risk (RR) for three-point major adverse cardiovascular events (3P-MACE) and its components by age subgroups (65 years; 75 years). RESULTS: For SGLT-2is, five CVOTs (46,969 patients, 45-50 % ≥65 years) were included. SGLT-2is reduced risk of MACE (RR; 0.91 [CI, 0.85-0.98]); cardiovascular death (CV-death) (RR; 0.84 [CI, 0.73-0.96]); and all-cause mortality (ACM) (RR; 0.86 [CI, 0.79-0.93]) with no difference in subgroups <65 or ≥65 years. For GLP-1RAs, nine CVOTs (n = 64,236, 34-75 % ≥65 years) were included. GLP-1RAs reduced risk of MACE (RR; 0.89 [CI, 0.83-0.95]), stroke (RR; 0.86 [CI, 0.76-0.97]) and ACM (RR; 0.90 [CI, 0.83-0.97]) with no significant difference in subgroups <65 or ≥65 years. Additionally, GLP-1RAs reduced risk of MACE (10 %), ACM (12 %) and CV-death (12 %) with no significant difference in subgroups <75 or ≥75 years. Four CVOTs (n = 33,063; 35-58 % ≥65 years) with DPP-4is were included. There were no significant differences in risk for CV outcomes with DPP-4is compared to placebo in any of the age subgroups. CONCLUSION: The overall cardiovascular safety profile of newer anti-hyperglycemic agents is consistent in older and younger individuals.