Background
Obstructive sleep apnea (
OSA
) is common and independently associated with atrial fibrillation (
AF
) in patients with hypertrophic cardiomyopathy (
HCM
). This study aimed to investigate the relationship between apnea‐hypopnea index (
AHI
), a measure of
OSA
severity, and prevalence of
AF
in a large series of patients with HCM.
Methods and Results
A total of 555 patients with HCM who underwent sleep evaluations were retrospectively included. Data from polysomnography studies, echocardiography, and baseline clinical characteristics were collected.
OSA
was present in 327 patients (58.9%). Patients with
OSA
or higher
AHI
quartiles were older, more often male, had a higher body mass index, and more clinical comorbidities. The prevalence of
AF
increased in patients with
OSA
(23.9% versus 13.6%,
P
=0.003) or across
AHI
quartiles (9.4%, 17.3%, 26.6%, and 25.2%, respectively;
P
for trend <0.001). After adjustment for age, sex, body mass index, New York Heart Association class, left atrial diameter, hypertension, oxygen desaturation index, and obstructive
HCM
, highest
AHI
quartile (odds ratio, 4.42; 95%
CI
, 1.35–14.52 [
P
=0.014]) or moderate to severe
OSA
(odds ratio, 3.03; 95%
CI
, 1.28–7.20 [
P
=0.012]) but not presence of
OSA
(odds ratio, 1.58; 95%
CI
, 0.84–2.97 [
P
=0.153]) were significantly associated with
AF
. Higher
AHI
levels were also factors associated with persistent or permanent
AF
(highest
AHI
quartile with odds ratio, 10.96; 95%
CI
, 1.07–111.85).
Conclusions
Severity of
AHI
level is independently associated with
AF
in patients with HCM. Clinical trials are required to determine the benefits of
OSA
treatment on
AF
in patients with HCM.