Masachika Tamura

Peak time of acute coronary syndrome in patients with sleep disordered breathing.

BACKGROUND Recently, sleep disordered breathing (SDB) has gained attention in the field of cardiology. Until now, no study describing the relationship between acute coronary syndrome (ACS) and SDB has been carried out in Japan. METHODS Among ACS patients admitted to our hospital, 44 patients (mean age 60.6+/-13.5 years) who received a portable polysomnography to measure apnea hypopnea index (AHI) were selected for this study. The circadian pattern of ACS onset was studied in 6-h intervals. In addition, all subjects were divided into three groups according to AHI severity (AHI < 5, 5 < or = AHI < 15, and 15 < or = AHI). Then, a comparative study between peak time of ACS and AHI severity was conducted for each group. RESULTS In the AHI < 5 group, 66.0% patients suffered from ACS between 12:00 h and 18:00 h and 17.0% between 18:00 h and 24:00 h, and a total of 83.0% patients had ACS between 12:00 h and 24:00 h. In the 5 < or = AHI < 15 group, 49.9% patients had ACS between 24:00 h and 06:00 h, 16.7% patients between 06:00 h and 12:00 h. 12:00-18:00 h and 18:00-24:00 h showed no significant difference. All 22 patients in the 15 < or = AHI group suffered from ACS between 24:00 h and 12:00 h. CONCLUSION The results of this study suggest a possible relationship between SDB and the onset of ACS between midnight to morning.

Health-related quality of life in relation to different levels of disease severity in patients with chronic heart failure

The purpose of the present study was to compare differences in physiological outcomes and health-related quality of life (HRQOL) in relation to degree of illness in patients with chronic heart failure (CHF) and to compare HRQOL in CHF patients with that of a normal Japanese population. One hundred and twenty-five patients with stable CHF (93 men, 32 women, mean age 63.3 ± 12.4 years) with left ventricular ejection fraction (LVEF) of less than 40% were enrolled in the present study. We used New York Heart Association (NYHA) functional class as an index of degree of illness. In 64 of the 125 patients, physiological outcome measures included peak oxygen uptake (peak O2) and E/CO2 slope. HRQOL was assessed with the medical outcome study short form-36 (SF-36) Japanese version. In addition, SF-36 scores of CHF patients were compared against Japanese standard values. Age and LVEF did not differ according to NYHA functional class. The eight SF-36 subscale scores and peak O2 decreased with increases in the NYHA functional classes, whereas E/CO2 slope increased with increases in NYHA functional class (p<0.05). Of the 8 SF-36 subscales measured in CHF patients, only the bodily pain score attained that of the normal Japanese population. These findings suggest that HRQOL decreases as NYHA functional class increases and other physiological measures worsen. In addition, HRQOL values of CHF patients were low in comparison with standard values of a normal Japanese population.