Predictors of heart rhythm disturbances in hypertensive obese patients with obstructive sleep apnea.

Objective: To assess the incidence and predictors of heart rhythm and conduction disturbances in hypertensive obese patients with and without obstructive sleep apnea (OSA).

Methods: This is an open, cohort, prospective study. Out of 493 screened patients, we selected 279 hypertensive, obese individuals without severe concomitant diseases: 75 patients without sleep-disordered breathing (non-SDB group), and 204 patients with OSA (OSA group). At baseline, all patients underwent examination, including ECG, Holter ECG monitoring, and sleep study. During follow-up (on 3, 5, 7 and 10th years; phone calls once per 6 months), information about new events, changes in therapy and life style was collected, diagnostic procedures were performed. As the endpoints, we registered significant heart rhythm and conduction disorders as following: atrial fibrillation (AF), ventricular tachycardia, atrioventricular block (AV) 2-3 degree, sinoatrial block, significant sinus pauses (> 2000 ms), and the required pacemaker implantation.

Results: The median follow-up was 108 (67.5-120) months. The frequency of heart rhythm disorders was higher in OSA patients (29 cases, χ 2 = 5.5; Р = 0.019) compared to the non-SDB patients (three cases; OR: 3.92, 95% CI: 1.16-13.29). AF was registered in 15 patients ( n = 12 in OSA group; Р = 0.77). Heart conduction disturbance developed in 16 patients, without an association with the rate of coronary artery disease onset. Regression analysis showed that only hypertension duration was an independent predictor of AF (OR: 1.10, 95% CI: 1.04-1.16; Р = 0.001). In case of heart conduction disturbances, apnea duration was the strongest predictor ( Р = 0.002).

Conclusions: Hypertensive obese patients with OSA demonstrate 4-fold higher incidence of heart rhythm and conduction disturbances than subjects without SDB. Hypertension duration is an independent predictor for AF development, while sleep apnea/hypopnea duration is the main factor for heart conduction disorders onset in hypertensive obese patients with OSA.