Obstructive sleep apnea is common and independently associated with atrial fibrillation in patients with hypertrophic cardiomyopathy.
BACKGROUND
Hypertrophic cardiomyopathy (HCM) is associated with arrhythmias and cardiovascular death. Left atrial enlargement and atrial fibrillation (AF) are considered markers for death due to heart failure in patients with HCM. Obstructive sleep apnea (OSA) is independently associated with heart remodeling and arrhythmias in other populations. We hypothesized that OSA is common and is associated with heart remodeling and AF in patients with HCM.


METHODS
We evaluated 80 consecutive stable patients with a confirmed diagnosis of HCM by sleep questionnaire, blood tests, echocardiography, and sleep study (overnight respiratory monitoring).


RESULTS
OSA (apnea-hypopnea index [AHI] > 15 events/h) was present in 32 patients (40%). Patients with OSA were significantly older (56 [41-64] vs 38.5 [30-53] years, P < .001) and presented higher BMI (28.2 +/- 3.5 vs 25.2 +/- 5.2 kg/m(2), P < .01) and increased left atrial diameter (45 [42-52.8] vs 41 [39-47] mm, P = .01) and aorta diameter (34 [30-37] vs 29 [28-32] mm, P < .001), compared with patients without OSA. Stepwise multiple linear regression showed that the AHI (P = .05) and BMI (P = .06) were associated with left atrial diameter. The AHI was the only variable associated with aorta diameter (P = .01). AF was present in 31% vs 6% of patients with and without OSA, respectively (P < .01). OSA (P = .03) and left atrial diameter (P = .03) were the only factors independently associated with AF.


CONCLUSIONS
OSA is highly prevalent in patients with HCM and it is associated with left atrial and aortic enlargement. OSA is independently associated with AF, a risk factor for cardiovascular death in this population.
Sleep Laboratory, Pulmonary Division, Heart Institute (InCor), Av. Enéas Carvalho de Aguiar, 44, São Paulo, Brazil.
Rodrigo P
RP
Pedrosa
Luciano F
LF
Drager
Pedro R
PR
Genta
Aline C S
AC
Amaro
Murillo O
MO
Antunes
Afonso Y
AY
Matsumoto
Edmundo
E
Arteaga
Charles
C
Mady
Geraldo
G
Lorenzi-Filho
D000328:Adult; D001281:Atrial Fibrillation / Q000453:epidemiology*; D002312:Cardiomyopathy, Hypertrophic / Q000453:epidemiology*; D015897:Comorbidity; D004452:Echocardiography; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D015995:Prevalence; D011446:Prospective Studies; D012189:Retrospective Studies; D020181:Sleep Apnea, Obstructive / Q000453:epidemiology*; D020257:Ventricular Remodeling