ABC | Volume 111, Nº3, September 2018

Original Article Medeiros et al Obstructive sleep apnea in chagas disease Arq Bras Cardiol. 2018; 111(3):364-372 Figura 1 – Diagrama de fluxo do paciente. Patients screened (n = 287) Exclusion: 149 Cardiac pacemaker: 91 Refused to participate: 25 Coronary disease: 17 Decompensated heart failure: 06 Chronic kidney disease: 05 Stroke: 03 Liver disease: 02 Included for sleep studies (n = 138) 3 losses Poor sleep study quality = 2 Predominance of central sleep apnea = 1 Analyzed (n = 135) Results We consecutively evaluated 287 patients with CD (41 [30%] with the indeterminate form of the disease and 94 [70%] with Chagas cardiomyopathy). Most of the exclusions were due to the presence of cardiac pacemakers (Figure 1). One patient had a predominance of central sleep apnea and was also excluded, resulting in a final sample of 135 patients (Figure 1). The frequency of OSA in patients with CD was 58%. Mild OSA was diagnosed in 50 patients (37%) and moderate‑to‑severe OSA (IAH ≥ 15 events/h) in 28 patients (21%). None of the participants had a previous OSA diagnosis. Patients withmoderate-to-severeOSA had larger neck and waist circumferences, a higher frequency of high blood pressure and a higher percentage of them were on diuretics, b-blockers and ACE inhibitors, as well as AT1 inhibitors compared to patients with mild and no OSA, respectively (Table 1).There was no difference in the degree of sleepiness (Epworth Sleepiness Scale) between the groups (Table 1). The demographics and clinical characteristics according with the absence or presence of OSA are described in Table 1. Overall, there were no clinically significant differences in supraventricular and ventricular arrhythmia frequencies across the three groups. However, there was a greater proportion of supraventricular paired in patients with moderate-to-severe OSA, compared with patients with mild and no OSA (50% vs 40% and 23%; p = 0.03), respectively. (Table 2) Patients with moderate-to-severe OSA had increased nocturnal blood pressure (119 ± 17 vs. 113 ± 13 and 110 ± 11 mmHg; p = 0.01) compared to patients with mild and no OSA, respectively (Table 3). The aorta size, left ventricular systolic and diastolic diameters, septum and posterior wall thickness were similar between groups. Left atrial diameter [37 (33‑42) vs. 35 (33-39) and 33 (30-36) mm, p < 0.01(Figure 2) and volume [66(54-95)vs. 46(39-65) and 42(35-56) mL/m 2 , p < 0.001] were larger in patients with moderate-to-severe OSA, compared with mild and no OSA groups, respectively(Table 3). These findings were significant when the whole study population was analyzed, as well as in the subgroup of patients with Chagas cardiomyopathy, but not in patients from the indeterminate group. Left ventricular longitudinal strain was 366