The impact of continuous positive airway pressure therapy on left atrial function assessed by 2D speckle tracking echocardiography in patients with obstructive sleep apnoea

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Obstructive sleep apnoea (OSA) is associated with left atrium (LA) remodelling and dysfunction, developing even before left ventricle (LV) hypertrophy and diastolic dysfunction. Two-dimensional speckle-tracking echocardiography (2D-STE) may help to detect subclinical LA dysfunction before irreversible cardiac changes. Purpose To evaluate changes of LA geometry and function after short term continuous positive airway pressure therapy (CPAP) for OSA using 2D-STE. Methods 47 obese patients aged between 18 to 65 years old were enrolled in the study. Control group (N=13) consisted of healthy subjects who either did not have OSA, or it was mild (apnea/hypopnea index (AHI) 5 – 14/ hour). OSA group (N=34) consisted of subjects with moderate or severe OSA (AHI ≥ 15/ hour). Transthoracic echocardiography and 2D STE analysis performed before and after 3 months of treatment with CPAP, for control group – at a baseline only. Statistical analyses were performed using the SPSS 27.0 software. The value of p<0.05 was considered as statistically significant. Results Control group was younger, had more female patients, and prevalence of arterial hypertension was lower compared to OSA group. All patients had preserved LV EF (>50 %) without significant differences between groups. OSA was related to more prevalent LV diastolic dysfunction (p = 0.023) and increased LV myocardial mass when indexed by height (46.11 (8.23) vs 38.96 (5.9) g/m 2.7, p = 0.007). OSA patients had significantly higher LA diameter (43.58 (8.19) vs 36.23 (3.08) mm, p <0.001), while LA volume did not differ even when indexed by height (p>0.05). LA reservoir strain was significantly lower in patients with OSA (26.56 (1.38) vs 31.01 (1.56) %, p<0.001) when compared to control group. After 3 months of CPAP treatment LA diameter, LA volume, LV MMi, LA conduit and contractile strain did not change , but prevalence of LV diastolic dysfunction decreased and LA reservoir strain improved. (Table 1). Conclusions Our study showed more prevalent LV diastolic dysfunction, increased LV myocardial mass indexed by height, together with reduced LA reservoir strain in OSA patients with preserved LV ejection fraction. Short term CPAP treatment significantly improved LV diastolic function and LA reservoir strain in OSA patients.