Author + information
- Naoki Serizawa, MD,
- Dai Yumino, MD* (, )
- Atsushi Takagi, MD and
- Nobuhisa Hagiwara, MD
- ↵*Department of Cardiology, Tokyo Women's Medical University 8-1, Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan
We appreciate the sincere comments of Dr. Meuleman and colleagues regarding our recent study (1). The authors argued that the presence of obstructive sleep apnea (OSA) is associated with thoracic aortic dilation. It was interesting that they also found that presence of aortic enlargement was associated with age and sex but not hypertension (2). Contrary to their findings, we have been able to show an association between OSA and thoracic aortic dilation (1). In their study, however, there are several major methodological concerns regarding the study design and diagnostic techniques to detect thoracic aortic dilation. First, one of the main concerns is that they only included patients with OSA, and did not include those without OSA (i.e., control group). This crucial concern may affect their results and may not determine whether OSA is associated with thoracic aortic dilation. Second, they included the initiation of continuous positive airway pressure for OSA, which we excluded from our study. As Cistulli et al. (3) showed, continuous positive airway pressure could stabilize the degree of thoracic aortic dilation in patients with Marfan syndrome, and this may have affected their results. Finally, there were differences in the modality and the location in measuring the size of aorta between their study and ours. Meuleman et al. (2) measured thoracic aortic dilation at the sinuses of Valsalva level using transthoracic echocardiography (TTE), while we measured the most dilated level of the ascending aorta using computed tomography. In fact, thoracic aortic dilation was measured in the ascending aorta above the level of the sinuses of Valsalva in all cases in our study. The correlation between TTE and computed tomography was shown when measurements were made not only at the sinuses of Valsalva level but also beyond the sino-tubular junction into the ascending aorta (4). Della Corte et al. (5) reported that dilation prevailed at the midascending aorta irrespective of valve function. Despite the fact that TTE is an excellent modality for noninvasive imaging of the aortic root, it has some limitations in imaging the middle or distal ascending aorta. It might be possible that the measurement of the ascending aorta using TTE could not indicate aortic dilation. Our study has shown a relationship between OSA and thoracic aortic dilation; however, further thorough investigations are required to elucidate the mechanism linking OSA and thoracic aortic dilation.
- American College of Cardiology Foundation