Hidden HFpEF in Atrial Fibrillation: A Missed Diagnosis with Real Consequences

Atrial fibrillation (AFib) and heart failure with preserved ejection fraction (HFpEF) frequently coexist, but the degree to which HFpEF goes unrecognized in AFib populations has been unclear. New insights from a post hoc analysis of the CABANA trial suggest this gap is far larger—and more clinically meaningful—than previously thought.

Using a validated probability tool (HFpEF-ABA), investigators found that approximately 70% of AFib patients without known heart failure had a high likelihood of undiagnosed HFpEF. Even more striking, nearly all patients reporting dyspnea had a high predicted probability of HFpEF, translating to an estimated 68% of the overall cohort with probable, previously unrecognized disease.

A Diagnostic Disconnect
One of the most revealing aspects of the study lies in the mismatch between patient-reported symptoms and clinician assessment. Despite reporting dyspnea, nearly half of these patients were still classified as NYHA Class I by investigators—effectively “asymptomatic.”

This misclassification matters. Patients with probable HFpEF had significantly worse quality of life, greater symptom burden, and a higher risk of both heart failure and cardiovascular hospitalization. Together, these findings suggest that dyspnea in AFib should prompt broader diagnostic consideration rather than being attributed solely to arrhythmia.

Symptom Relief Without Risk Reduction
Catheter ablation, a cornerstone of rhythm control, showed nuanced benefits in this population. Patients with probable HFpEF experienced greater improvements in symptom burden and quality of life following ablation compared with those without HFpEF. However, patients experienced no significant reduction in heart failure hospitalizations, along with persistent residual symptom burden and continued elevated cardiovascular risk despite rhythm control.

In practical terms, while ablation may improve how patients feel, it doesn’t necessarily address the broader risk profile associated with probable HFpEF.

Why This Matters for Clinical Practice
This data suggests that in patients presenting with dyspnea, HFpEF should be actively considered rather than viewed as a secondary possibility.

Within clinical workflows, a more integrated approach becomes essential. Noninvasive tools like the HFpEF-ABA score can help identify patients at elevated risk, particularly when echocardiographic data are limited or inconclusive. At the same time, patient-reported outcome measures, such as MAFSI and EQ-5D, often capture functional impairment more accurately than clinician assessment alone.

When it comes to treatment, unlike rhythm control strategies, HFpEF now has evidence-based therapies, including SGLT2 inhibitors and mineralocorticoid receptor antagonists. Management of cardiometabolic comorbidities also plays a central role in improving outcomes. But these therapies can only be deployed if HFpEF is recognized.

For patients with AFib and dyspnea, the message is clear: probable HFpEF is common and frequently overlooked. A more integrated approach that combines symptom evaluation, probability-based screening, and early initiation of HFpEF therapies may ultimately help address risks that ablation alone cannot.

Reference

Reddy YNV, Bergeron N, Carter RE, Redfield MM, Borlaug BA. Burden of potentially undiagnosed heart failure with preserved ejection fraction in atrial fibrillation and effects of catheter ablation: insights from CABANA. J Am Heart Assoc. 2026;15:e047295. doi:10.1161/JAHA.125.047295