More than 70% of patients with resistant hypertension have obstructive sleep apnea (OSA). However, whether continuous positive airway pressure (CPAP) for OSA improves blood pressure in patients with resistant hypertension is unknown.  This was a randomized controlled trial of CPAP in 194 patients with resistant hypertension in the setting of OSA. The primary outcome was the change in 24-hour ambulatory mean blood pressure (AMBP) from baseline to 12 weeks post-randomization. Medical therapy used for resistant hypertension did not differ between the two groups. Patients treated with CPAP showed a greater decrease in 24-hour AMBP (3.1mmHg, 95% CI 0.6-5.6mmHg, p=.02). In analyses restricted to patients tolerant of CPAP, akin to an on-treatment analysis, the intervention resulted in a larger decrease in AMBP (4.4mmHg, 95% CI 1.8-7mmHg). Furthermore, each hour of CPAP use was associated with a 1.3 mmHg decrease in AMBP.

Conclusion

Among patients with OSA and resistant hypertension, CPAP therapy for 12 weeks resulted in improvements in 24-hour ambulatory blood pressure. The degree of blood pressure change was small, but could have meaningful effects on cardiovascular mortality.

 Summarized by Steven M. Bradley and Supriya Shore

• Martínez-García MA, Capote F, Campos-Rodríguez F, Lloberes P, Díaz de Atauri MJ, Somoza M, Masa JF, González M, Sacristán L, Barbé F, Durán-Cantolla J, Aizpuru F, Mañas E, Barreiro B, Mosteiro M, Cebrián JJ, de la Peña M, García-Río F, Maimó A, Zapater J, Hernández C, Grau SanMarti N, Montserrat JM; Spanish Sleep Network. Effect of CPAP on blood pressure in patients with obstructive sleep apnea and resistant hypertension: the HIPARCO randomized clinical trial. JAMA. 2013 Dec 11;310(22):2407-15.