The impact of atrial fibrillation on the diagnostic yield of heart failure with reduced ejection fraction by open access echocardiography
journal contribution
posted on 2024-02-29, 14:52authored byKristina Church, Brian Li
Introduction: Guidelines recommend providing primary care
practitioners direct access to echocardiography (echo), prior to specialist
cardiology input, in patients whom they suspect have heart failure,
based on symptoms and raised N-Terminal pro Brain Natriuretic Peptide
(NTproBNP). Early access can lead to increased detection of Heart Failure
with a reduced Ejection Fraction (HFrEF). However, it is noted that Atrial
Fibrillation (AF) may contribute to falsely raised NTproBNP levels, and
this is thought to reduce the diagnostic yield of HFrEF. As a result, some
services exclude patients with AF from their direct access pathways. We
sought to determine the true burden of AF on the diagnostic yield within
our local health economy, to evaluate whether existing Open Access
Echocardiography (OAE) pathways should be modified in this group of
patients to improve cost-effectiveness.
Methods: The study cohort included all consecutive patients who
received an echo via the OAE pathway between January 2017 and
September 2019. The cohort was grouped based on NTproBNP levels,
pre-referral, into group A (400-2000 ng/L) and B (>2000 ng/L). The
diagnostic yield in patients with and without AF in both groups were
calculated as the percentage of patients with a positive diagnosis of
HFrEF compared to those with a normal ejection fraction (nEF). These
were compared using independent sample t-tests for nominal variables
and chi-square tests for dichotomous and categorical variables.
Results: Over 32 months, 487 patients met our OAE criteria and received
an echo. 164 patients were ≤75 years old and 323 were >75 years old.
Median age was 77 years (IQR 72-84) and 48.8% were male. Overall
diagnostic yield for HFrEF was 20.4% vs 35.7% in GpA vs GpB patients
(p<0.001). In GpA, there were 140 patients with AF and 196 without AF. The
median NTproBNP in the two subgroups were 1043 ng/mL (IQR 845-1443)
vs 701 ng/mL (IQR 548-1137) (p<0.001), and diagnostic yield was 17% and
21% respectively (p=0.27). In GpB, there were 90 patients with AF and 61
without AF. The median NTproBNP in the two subgroups was 3019 ng/mL
(IQR 2323-3986) vs 3567 ng/mL (IQR 2636-5298) (p=0.821), with diagnostic
yield returning at 34% vs 37.7% respectively (p=0.68).
Conclusion: Our results demonstrate that very high NTproBNP levels
were associated with a significantly higher diagnostic yield for HFrEF
with a 15% improvement at the higher threshold. AF was associated with
significantly higher NTproBNP levels in patients at the lower threshold but
not at the higher threshold, however this did not translate into a clinically
meaningful difference in the overall diagnostic yield of HFrEF. Based on
our results, raising NTproBNP thresholds for AF patients or excluding them
from screening pathways is not recommended. Alternative measures,
such as the use of novel biomarkers, may improve the diagnostic yield of
HFrEF in patients with modestly elevated NTproBNP.
History
Refereed
No
Volume
6
Issue number
Suppl 1
Publication title
European Journal of Arrhythmia & Electrophysiology