Daily Cardiology Research Analysis
Three impactful cardiology studies stand out today: a NEJM randomized trial shows the factor XI inhibitor abelacimab markedly reduces bleeding versus rivaroxaban in atrial fibrillation; a Circulation analysis refines NT-proBNP diagnostic thresholds for HFpEF by BMI and atrial fibrillation status; and a JAMA Cardiology cohort links supine hypertension to substantially higher cardiovascular risk independent of seated blood pressure.
Summary
Three impactful cardiology studies stand out today: a NEJM randomized trial shows the factor XI inhibitor abelacimab markedly reduces bleeding versus rivaroxaban in atrial fibrillation; a Circulation analysis refines NT-proBNP diagnostic thresholds for HFpEF by BMI and atrial fibrillation status; and a JAMA Cardiology cohort links supine hypertension to substantially higher cardiovascular risk independent of seated blood pressure.
Research Themes
- Novel anticoagulation targeting factor XI to reduce bleeding in AF
- Optimizing HFpEF diagnosis using NT-proBNP stratified by BMI and atrial fibrillation
- Supine blood pressure as an independent predictor of cardiovascular outcomes
Selected Articles
1. Abelacimab versus Rivaroxaban in Patients with Atrial Fibrillation.
In a randomized comparison in AF, monthly abelacimab reduced free factor XI by ~97–99% and cut major/CRNM bleeding by 62–69% versus rivaroxaban, leading to early trial termination. Adverse event profiles were similar across arms.
Impact: Demonstrates clinical safety advantage of factor XI inhibition over a standard DOAC, supporting a paradigm shift to decouple anticoagulation from hemostasis.
Clinical Implications: For AF patients at moderate-to-high stroke risk, factor XI pathway inhibition may substantially lower bleeding compared with factor Xa inhibition while maintaining anticoagulant effect; practice may pivot to monthly parenteral options pending efficacy data.
Key Findings
- Free factor XI reduced by median 99% (150 mg) and 97% (90 mg) at 3 months.
- Major or CRNM bleeding: 3.2 and 2.6 vs 8.4 events/100 person-years (HR 0.38 and 0.31 vs rivaroxaban; P<0.001).
- Adverse event incidence and severity were similar across groups; trial stopped early due to larger-than-expected bleeding reduction.
Methodological Strengths
- Randomized, multicenter design with blinded administration of abelacimab and independent data monitoring.
- Hard safety endpoint with event rates presented per person-years and hazard ratios with narrow CIs.
Limitations
- Open-label comparator arm (rivaroxaban) may introduce performance bias.
- Trial stopped early; efficacy outcomes (stroke/systemic embolism) not reported in the abstract.
Future Directions: Confirm stroke prevention efficacy versus DOACs, assess long-term safety, and compare fixed monthly dosing versus oral regimens across diverse AF subgroups (e.g., CKD, frailty).
BACKGROUND: Abelacimab is a fully human monoclonal antibody that binds to the inactive form of factor XI and blocks its activation. The safety of abelacimab as compared with a direct oral anticoagulant in patients with atrial fibrillation is unknown. METHODS: Patients with atrial fibrillation and a moderate-to-high risk of stroke were randomly assigned, in a 1:1:1 ratio, to receive subcutaneous injection of abelacimab (150 mg or 90 mg once monthly) administered in a blinded fashion or oral rivaroxaban (20 mg once daily) administered in an open-label fashion. The primary end point was major or clinically relevant nonmajor bleeding. RESULTS: A total of 1287 patients underwent randomization; the median age was 74 years, and 44% were women. At 3 months, the median reduction in free factor XI levels with abelacimab at a dose of 150 mg was 99% (interquartile range, 98 to 99) and with abelacimab at a dose of 90 mg was 97% (interquartile range, 51 to 99). The trial was stopped early on the recommendation of the independent data monitoring committee because of a greater-than-anticipated reduction in bleeding events with abelacimab. The incidence rate of major or clinically relevant nonmajor bleeding was 3.2 events per 100 person-years with 150-mg abelacimab and 2.6 events per 100 person-years with 90-mg abelacimab, as compared with 8.4 events per 100 person-years with rivaroxaban (hazard ratio for 150-mg abelacimab vs. rivaroxaban, 0.38 [95% confidence interval {CI}, 0.24 to 0.60]; hazard ratio for 90-mg abelacimab vs. rivaroxaban, 0.31 [95% CI, 0.19 to 0.51]; P<0.001 for both comparisons). The incidence and severity of adverse events appeared to be similar in the three groups. CONCLUSIONS: Among patients with atrial fibrillation who were at moderate-to-high risk for stroke, treatment with abelacimab resulted in markedly lower levels of free factor XI and fewer bleeding events than treatment with rivaroxaban. (Funded by Anthos Therapeutics; AZALEA-TIMI 71 ClinicalTrials.gov number, NCT04755283.).
2. Evidence-Based Application of Natriuretic Peptides in the Evaluation of Chronic Heart Failure With Preserved Ejection Fraction in the Ambulatory Outpatient Setting.
Across derivation and multiple validation cohorts using gold-standard exercise catheterization, standard NT-proBNP thresholds misclassified HFpEF, particularly in obesity and AF. BMI- and AF-stratified rule-in/out thresholds substantially reduce error; in AF with dyspnea, NT-proBNP adds little beyond AF status itself.
Impact: Refines a ubiquitous diagnostic test by context-specific thresholds, directly addressing common sources of misclassification in HFpEF workups.
Clinical Implications: Adopt BMI- and AF-stratified NT-proBNP thresholds in outpatient dyspnea to triage for exercise hemodynamic testing; avoid over-reliance on low thresholds in obesity or AF.
Key Findings
- Diagnostic reference standard was exercise catheterization; derivation (n=414) and multiple validation cohorts (n=560, 207, 77) plus three external validations.
- Conventional rule-out threshold (<125 pg/mL) yielded high error rates; performance varied by BMI and AF.
- In patients with AF and dyspnea, NT-proBNP provided limited incremental diagnostic value; BMI-stratified thresholds improved classification.
Methodological Strengths
- Gold-standard invasive exercise hemodynamics for diagnosis; multicenter validation.
- Predefined stratification by BMI and AF with external validations across different diagnostic reference standards.
Limitations
- Exact cut-points and operating characteristics are not detailed in the abstract.
- Generalizability to acute care settings or populations without chronic dyspnea is uncertain.
Future Directions: Prospective implementation studies to test BMI-/AF-stratified algorithms on clinical pathways, outcomes, and resource use; integration with echocardiography/AI models.
BACKGROUND: Plasma NT-proBNP (N-terminal pro-B-type natriuretic peptide) is commonly used to diagnose heart failure with preserved ejection fraction (HFpEF), but its diagnostic performance in the ambulatory/outpatient setting is unknown because previous studies lacked objective reference standards. METHODS: Among patients with chronic dyspnea, diagnosis of HFpEF or noncardiac dyspnea was determined conclusively by exercise catheterization in a derivation cohort (n=414), multicenter validation cohort 1 (n=560), validation cohort 2 (n=207), and a nonobese Japanese validation cohort 3 (n=77). Optimal NT-proBNP cut points for HFpEF rule out (optimizing sensitivity) and rule in (optimizing specificity) were derived and tested, stratified by obesity and atrial fibrillation. Derived cut points were tested in 3 additional validation cohorts (cohorts 4-6) in whom HFpEF was diagnosed by resting catheterization only (n=260), previous hospitalization for heart failure (n=447), or exercise echocardiography (n=517), respectively. RESULTS: Current recommended rule-out NT-proBNP threshold <125 pg/mL had 82% sensitivity (95% CI, 77%-88%) with a body mass index (BMI) <35 kg/m CONCLUSIONS: In patients with chronic unexplained dyspnea, current rule-in and rule-out NT-proBNP diagnostic thresholds lead to unacceptably high error rates, with important interactions by obesity and AF status. In our study, NT-proBNP provided little value in those with AF and dyspnea because the presence of AF is by itself a robust biomarker of HFpEF. Use of separate rule-in and rule-out diagnostic thresholds stratified by BMI reduces miscategorization and can guide more appropriate use of exercise testing for possible HFpEF.
3. Supine Blood Pressure and Risk of Cardiovascular Disease and Mortality.
In ARIC (n=11,369) with ~26–28 years follow-up, supine hypertension was associated with higher risks of CHD, HF, stroke, fatal CHD, and all-cause mortality, independent of seated BP and treatment status. Supine-only hypertension carried risks comparable to hypertension in both positions and exceeded seated-only hypertension.
Impact: Establishes supine BP as a clinically meaningful phenotype with prognostic value beyond seated BP, potentially changing screening and management strategies.
Clinical Implications: Incorporate supine BP measurement in risk assessment; consider targeting supine hypertension even when seated BP is controlled, and evaluate its relation to nocturnal hypertension.
Key Findings
- Supine hypertension prevalence: 16.4% without seated HTN; 73.5% with seated HTN.
- Supine hypertension associated with CHD (HR 1.60), HF (1.83), stroke (1.86), fatal CHD (2.18), all-cause mortality (1.43).
- Supine-only hypertension conferred risks similar to both-position hypertension and higher than seated-only hypertension.
Methodological Strengths
- Large, community-based prospective cohort with ~27 years of surveillance.
- Adjusted Cox models; consistent findings across seated BP strata and medication use.
Limitations
- Supine BP measured in clinic setting, not nocturnal ambulatory BP; residual confounding possible.
- Causality cannot be inferred due to observational design.
Future Directions: Test interventions targeting supine hypertension (e.g., medication timing, positional therapy) and integrate supine BP into risk calculators alongside ambulatory BP phenotypes.
IMPORTANCE: Nocturnal hypertension while asleep is associated with substantial increases in risk of cardiovascular disease (CVD) and death. Whether hypertension while supine is a risk factor associated with CVD independent of seated hypertension remains unknown. OBJECTIVE: To investigate the association between supine hypertension and CVD outcomes and by hypertension treatment status. DESIGN, SETTING, AND PARTICIPANTS: This prospective cohort study used data from the Atherosclerosis Risk in Communities (ARIC) study, which was established in 1987 to examine cardiovascular risk factors among middle-aged adults from 4 communities in the US. Supine and seated blood pressure were measured in more than 13 000 middle-aged adults with longitudinal surveillance for CVD over 27 years. Participants with a history of coronary heart disease (CHD), heart failure, or stroke were excluded. Data were analyzed from May 2023 through December 2024. EXPOSURES: Supine hypertension (supine systolic blood pressure ≥130 or diastolic blood pressure ≥80 mm Hg) with and without seated hypertension (seated systolic blood pressure ≥130 or diastolic blood pressure ≥80 mm Hg). MAIN OUTCOMES AND MEASURES: Cox proportional hazard models with adjustment for CVD risk factors were performed to investigate the association of supine hypertension with and without seated hypertension with incident CHD, heart failure, stroke, fatal CHD, and all-cause mortality. RESULTS: Of 11 369 participants without known CVD (6332 female [55.7%] and 5037 male [44.3%]; 2858 Black [25.1%] and 8511 White [74.9%]; mean [SD] age 53.9 [5.7] years]), 16.4% (95% CI, 15.5%-17.2%) of those without seated hypertension had supine hypertension and 73.5% (95% CI, 72.2%-74.8%) of those with seated hypertension had supine hypertension. Supine hypertension was associated with incident CHD (hazard ratio [HR], 1.60; 95% CI, 1.45-1.76), heart failure (HR, 1.83; 95% CI, 1.68-2.01), stroke (HR, 1.86; 95% CI, 1.63-2.13), fatal CHD (HR, 2.18; 95% CI, 1.84-2.59), and all-cause mortality (HR, 1.43; 95% CI, 1.35-1.52) during a median (25th, 75th percentile) follow-up of 25.7 (15.4, 30.4) years, 26.9 (17.6, 30.5) years, 27.6 (18.5, 30.6 years), 28.3 (20.5, 30.7) years, and 28.3 (20.5 years, 30.7) years, respectively. There were no meaningful differences by seated hypertension status. Results were similar by hypertension medication use. Participants with supine hypertension alone had risk associations similar to those of participants with hypertension in both positions and significantly greater than those of participants with seated hypertension alone with the exception of fatal CHD; seated vs supine HRs were 0.72 (95% CI, 0.61-0.85) for CHD, 0.72 (95% CI, 0.60-0.85) for heart failure, 0.66 (95% CI, 0.51-0.86) for stroke, and 0.83 (95% CI, 0.74-0.92) for all-cause mortality. CONCLUSIONS AND RELEVANCE: Supine hypertension regardless of seated hypertension had a higher HR for CVD risk than seated hypertension alone. Future research should evaluate supine hypertension in the setting of nocturnal hypertension and as an independent target of blood pressure treatment.