Long-term adherence to nasal continuous positive airway pressure therapy by hypertensive patients with preexisting sleep apnea.

BACKGROUND AND OBJECTIVE: Although positive screening for and treatment of obstructive sleep apnea (OSA) have been recommended for patients with cardiovascular problems, patient adherence to nasal continuous positive airway pressure (CPAP) therapy primarily for a cardiovascular concern is unknown. Therefore, this study aimed to determine the adherence to CPAP therapy by hypertensive patients with OSA after a screening test performed regardless of OSA-related symptoms. SUBJECTS AND METHODS: CPAP therapy was administered to 194 of the 1365 hypertensive patients who underwent the screening. The monthly dropout from CPAP therapy and the adequate use level (4h every night, 70% days in a month) were assessed using the Kaplan-Meier analysis over a 3-year follow-up period. RESULTS: Of the patients, 106 (55%) refused or abandoned the therapy by the end of the follow-up period (adherence, 45%). An adequate use level was maintained by 76 patients (39%). Most of the patients' background characteristics, including age, sex, Epworth sleepiness scale scores, and parameters obtained on polysomnography, were not related to adherence or adequate use level. The good-compliance level on the first visit after CPAP therapy introduction was most strongly related to adherence (95% CI, 0.05-0.32; p<0.001) and adequate use level (95% CI, 0.06-0.33; p<0.05). Fourth quartile of apnea hypopnea index value (greater than 67/h) was also related to adherence (95% CI, 0.21-0.98; p<0.02) and adequate use level (95% CI, 0.19-0.88; p<0.05). CONCLUSIONS: The adherence and use level in this population may not be satisfactory but are comparable with those in previous sleep center reports treating symptomatic OSA patients. Thus, the present results would encourage hypertensive patients to undergo positive screening for OSA, regardless of OSA-related symptoms. However, an outcomes study with the same cohort is needed.

Predominant microvessel proliferation in coronary stent restenotic tissue in patients with diabetes: insights from optical coherence tomography image analysis.

BACKGROUND: Coronary optical coherence tomography (OCT) enables virtual depiction of histological findings of in-stent restenotic tissue. The aim of this study was to investigate the microvessel proliferation within in-stent restenotic tissue and the influence of diabetes mellitus (DM). METHODS: We examined 54 in-stent restenotic coronary artery lesions (stenotic area>50%) from 50 consecutive patients including 28 with DM (56%) and 9 insulin-treated DM patients (18%); who underwent coronary time-domain OCT imaging with automatic pull back (1mm/s, 20 frames/s). Microvessels were defined as low-signal cavities with a diameter of 50-150 microns and a trajectory parallel to the lumen recognized on 3 consecutive cross-sectional OCT image frames. The microvessel index was calculated as the number of frames with microvessel/total number of frames × 100. Patients were stratified into 3 groups: 1) without microvessels, 2) with a low (< median value) microvessel index, 3) with a high microvessel index. RESULTS: Microvessels were detected in 566 frames (3.1%) from 26 lesions (48%) in 24 patients (48%). A greater incidence of DM and higher serum glucose levels were observed in the high microvessel index group (DM: 42% vs 58% vs 83%, p=0.049; serum glucose level: 118.2 ± 44.6 vs 122.6 ± 31.0 vs 172.8 ± 63.1mg/dL, p=0.03 between low and high microvessel index group, p=0.005 between no microvessel and high microvessel index group). CONCLUSIONS: Microvessel formation may be a unique pathophysiological factor of in-stent restenoses in patients with DM.

[Comparison of portable apnea monitors in the detection of apnea episode during daytime rest].

Although polysomnography (PSG) is the golden standard for the diagnosis of sleep apnea syndrome (SAS), access to this procedure is limited because it requires special institution and trained technicians. Therefore, many portable recording devices have been developed for detection of SAS including home monitoring. The present study evaluated the usefulness of four portable devices in detecting apneic events. The four devices are, (1) FM-500 thermister sensor type III device, (2) LS-300 pressure sensor type III device, (3) Morpheus pressure sensor type III device, and (4) SD-101, a sheet-type type IV device that detects chest wall movement. This study included 1,114 patients who underwent a daytime rest session during a routine clinic visit. The subjects were asked to remain quiet and in a supine position in a dark room. We compared the respiratory disturbance index (RDI) and number of oxygen desaturation events (OD) measured by the four portable devices in each patient. The RDI and number of OD measured by the device using the thermister sensor were significantly lower than those measured by the three other devices. These findings suggest that when using a portable recording device to screen for SAS, the characteristics of the device should be taken into account.