Severe sleep obstructive apnea in children. Can respiratory polygraphy estimate pulmonary pressure and right heart function

Background: Obstructive sleep apnea (OSA) can cause pulmonary hypertension and cor pulmonale in early childhood. Objetives: To study the association among apnea-hypopnea index (AHI), mean pulmonary artery pressure (mPAP) and right ventricular function by tricuspid Tei index, in children with severe OSA. To estimate the risk of developing pulmonary hypertension and right ventricular dysfunction. Methods: A prospective cohort study was performed between March 2013 and January 2016. Two groups were studied; group 1 (G1) (children with severe OSA due to adenotonsillar hypertrophy) and group 2 (G2) (healthy children). AHI was measured by nocturnal polygraphy. Tricuspid Tei index and mPAP were estimated by Doppler echocardiography. Association among AHI, mPAP and tricuspid Tei index was estimated using Pearson9s rho. Continuous variables were compared by Student9s t-test. Strength of association was calculated using relative risk (RR). Results: 60 children were studied; 30 in G1 (mean age 3.8±0.73 years) and 30 in G2 (4.1± 0.53 years). Tricuspid Tei index and mPAP were significantly increased in G1 vs G2 (0.39 ± 0.04 vs 0.36 ± 0.03 and 18.98 ± 2.38 mmHg vs 14.77±2.47 mmHg, respectively). A significant correlation was found between AHI and mPAP (r=0.33) and AHI and tricuspid Tei index (r=0.34). In G1, RR of mPAP > 20 mmHg and RR of Tricuspid Tei index > 0.37 was 7.8 (95% CI=1.96-31.6) and 5.5 (95%CI=1.8-16.6) respectively. Conclusion: Severe OSA diagnosed by nocturnal polygraphy is a risk factor for increasing mPAP and right ventricular dysfunction. A weak but significant association was found between AHI and mPAP and AHI and tricuspid Tei.