Association Between the Redox State of Human Serum Albumin and Exercise Capacity in Patients With Cardiac Disease.

The redox state of human serum albumin (HSA) is reported to be an oxidative stress biomarker; however, its clinical use in cardiac disease has not yet been examined. This study aimed to investigate the relation between the redox state of HSA and exercise capacity, which is a robust prognostic factor, in patients with cardiovascular disease. This cross-sectional study included outpatients with cardiac disease. Exercise capacity was assessed by peak oxygen consumption (peakVO2) measured using symptom-limited cardiopulmonary exercise testing. The high-performance liquid chromatography postcolumn bromocresol green method was used to part HSA into human nonmercaptalbumin (oxidized form) and human mercaptalbumin (HMA, reduced form). The fraction of human mercaptalbumin found in HSA (f[HMA]) was calculated as an indicator of the redox state of HSA. The association between peakVO2 and f(HMA) was examined using the Spearman correlation coefficient and multivariate linear regression analysis. A total of 70 patients were included (median age 76 years; 44 men; median peakVO2 15.5 ml/kg/min). The f(HMA) was positively correlated with peakVO2 (r = 0.38, p <0.01). Even after controlling for potential confounders, this association remained in the multivariate linear regression analysis (standardized beta = 0.24, p <0.05). We found a positive association between f(HMA) and peakVO2, independent of potential confounders in patients with cardiac disease, suggesting that f(HMA) may be a novel biomarker related to exercise capacity in cardiac disease. Longitudinal studies are required to further examine the prognostic capability of f(HMA), the responsiveness to clinical intervention, and the association between f(HMA) and cardiac disease.

Changes in mitral regurgitation and left ventricular geometry during exercise affect exercise capacity in patients with systolic heart failure.

AIMS: exercise may dramatically change the extent of functional mitral regurgitation (MR) and left ventricular (LV) geometry in patients with chronic heart failure (CHF). We hypothesized that dynamic changes in MR and LV geometry would affect exercise capacity. METHODS AND RESULTS: this study included 30 CHF patients with functional MR who underwent symptom-limited bicycle exercise stress echocardiography and cardiopulmonary exercise testing for quantitative assessment of MR (effective regurgitant orifice; ERO), and pulmonary artery systolic pressure (PASP). LV sphericity index was obtained from real-time three-dimensional echocardiograms. The patients were stratified into exercised-induced MR (EMR; n = 10, an increase in ERO by ≥13 mm(2)) or non-EMR (NEMR; n = 20, an increase in ERO by <13 mm(2)) group. At rest, no differences in LV volume and function, ERO, and PASP were found between the two groups. At peak exercise, PASP and sphericity index were significantly greater (all P < 0.01) in the EMR group. The EMR group revealed lower peak oxygen uptake (peak VO(2); P = 0.018) and greater minute ventilation/carbon dioxide production slope (VE/VCO(2) slope; P = 0.042) than the NEMR group. Peak VO(2) negatively correlated with changes in ERO (r = -0.628) and LV sphericity index (r = -0.437); meanwhile, VE/VCO(2) slope was well correlated with these changes (r = 0.414 and 0.364, respectively). A multivariate analysis identified that the change in ERO was the strongest predictor of peak VO(2) (P = 0.001). CONCLUSION: dynamic changes in MR and LV geometry contributed to the limitation of exercise capacity in patients with CHF.

Global longitudinal strain by two-dimensional speckle tracking imaging predicts exercise capacity in patients with chronic heart failure.

BACKGROUND: Left ventricular ejection fraction (LVEF) predicts mortality in patients with chronic heart failure (CHF). However, a weak correlation was found between LVEF and peak oxygen uptake ([Formula: see text]) in CHF patients. Global longitudinal strain measured by two-dimensional (2D) strain is regarded as a more useful predictor of cardiac events than LVEF. We investigated whether 2D strain obtained at rest could predict peak [Formula: see text] in patients with CHF. METHODS: Fifty-one patients (mean age of 54.0 ± 12.0 years, 14 females, LVEF 46.0 ± 15.0%) with stable CHF underwent resting echocardiography and cardiopulmonary exercise testing. Leg muscle strength was measured for the evaluation of peripheral factors. Global longitudinal strain (GLS) in the apical 4-, 3-, and 2-chamber views and global circumferential strain (GCS) in the parasternal mid short-axis view were measured. RESULTS: In all patients, peak [Formula: see text] correlated with leg muscle strength (r = 0.55, p < 0.0001), LVEF (r = 0.46, p < 0.001), GLS (r = -0.45, p < 0.001), and GCS (r = -0.41, p = 0.005), respectively. No significant correlation was found between the ratio of early transmitral velocity to peak early diastolic mitral annulus velocity (E/E') and peak [Formula: see text]. In the patients with heart failure and reduced LVEF, a multiple stepwise linear regression analysis based on leg muscle strength, LVEF, E/E', GLS, and GCS was performed to identify independent predictors of peak [Formula: see text], resulting in leg muscle strength and GLS (R (2) = 0.888) as independent predictors of peak [Formula: see text]. CONCLUSION: Global longitudinal strain at rest could possibly predict exercise capacity, which appeared to be more useful than LVEF, E/E', and GCS in CHF patients with reduced LVEF.

Hyperventilation and cold-pressor stress echocardiography combined with automated functional imaging non-invasively detected vasospastic angina.

A 47-year-old male presented with chest discomfort while sleeping. The patient was suspected of having vasospastic angina (VSA) and underwent hyperventilation and cold-pressor stress echocardiography. No chest pain, ECG changes or decreased wall motion was found. However, automated function imaging (AFI) showed decreased peak systolic strain at the apex and postsystolic shortening at both the apex and inferior wall, which was not found before the test. The provocation test revealed 99% stenosis in the right coronary artery #2 at a dose of 50 µg acetylcholine and 90% stenosis in the left coronary artery #8 at a dose of 100 µg. The patient was thus diagnosed as having VSA. The present case demonstrates the usefulness of AFI combined with hyperventilation and cold-pressor stress echocardiography as a screening examination for VSA.

Three-dimensional echocardiographic assessments of exercise-induced changes in left ventricular shape and dyssynchrony in patients with dynamic functional mitral regurgitation.

AIMS: Left ventricular (LV) shape and LV dyssynchrony are two cofactors associated with functional mitral regurgitation (MR) in patients with heart failure. Both can be accurately examined by real-time three-dimensional echocardiography (3DE). We examined the relationship between dynamic MR and exercise-induced changes in LV shape and synchronicity using 3DE. METHODS AND RESULTS: Fifty patients with systolic LV dysfunction underwent 2D and 3D quantitative assessment of LV function, shape, and synchronicity at rest and during symptom-limited exercise test. According to the magnitude of change in MR, patients were divided into EMR group (15 patients, 30%), if the degree of MR increased during test, and NEMR group. During exercise, the changes in LV volumes and ejection fraction were similar in both groups, whereas changes in mitral valvular deformation parameters, in LV sphericity index, and in the extent of LV dyssynchrony were more pronounced in the EMR group. At rest, only the 3D sphericity index could distinguish the two groups. By stepwise multiple regression model, dynamic changes in the systolic dyssynchrony index, sphericity index, and coaptation distance were associated with dynamic MR (r(2) = 0.45, P = 0.012). CONCLUSION: Dynamic MR during exercise is related to the 3D changes in LV shape and in LV synchronicity.

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.

Relationship between sleep-disordered breathing level and acute onset time of congestive heart failure.

Sleep-disordered breathing (SDB) is frequently observed in patients with congestive heart failure. Recent studies have shown that SDB negatively affects the onset of congestive heart failure; however, no studies have addressed the relationship between the level of SDB and the onset time of acute dyspnea. We hypothesized that SDB affects the acute onset time of dyspnea (AOT) and investigated the relationship between SDB and AOT. We examined 80 patients (mean age, 61.6 years) with congestive heart failure in a clinically stable condition. AOT was divided into 5 time periods (0:00 - 6:00, 6:00 - 12:00, 12:00 - 18:00, 18:00 - 24:00, and unknown). The apnea-hypopnea index (AHI) was obtained based on the results of polysomnography (PSG) to evaluate the severity of SDB. Acute dyspnea occurred in 59 (73.7%) of the 80 patients. When we divided the patients into an AHI < 5 group and an AHI >or= 5 group, there was no significant difference in the AOT; however, a significant difference was observed in those divided into AHI < 20 and AHI >or= 20 groups (P < 0.001). The patients with AHI >or= 20 had more acute dys-pnea between 18:00 - 24:00 and between 0:00 - 6:00 than those with AHI < 20 (32% and 19%, and 4.1% and 4.1%, respectively). Severe SDB patients tended to have acute dyspnea between midnight and dawn. The results suggest SDB might be one of the risk factors of heart failure.

Functional capacity, skeletal muscle strength, and skeletal muscle volume in patients with myocardial infarction.

Previous studies have reported that skeletal muscle strength is closely related to exercise capacity in patients with myocardial infarction (MI). However, none of the previous studies have fully investigated the correlation between exercise capacity and the skeletal muscle volume (MV). Seventy patients with MI underwent symptom-limited cardiopulmonary exercise testing using a treadmill. The MV was evaluated by electrical impedance analysis and the maximal knee extension strength (Peak torque: PT) was measured by a Biodex. The subjects were divided into 2 groups according to the MV (group L, MV < 22 kg; group H, MV > or = 22 kg). The PT was positively and significantly correlated with the peak V(.)O(2) in both the L and H groups (r = 0.70 versus r = 0.71). The MV of the lower limbs was positively correlated with the peak V(.)O(2) in the L group (r = 0.57), but not in the H group. The lower limb MV was positively and significantly correlated with PT in the L group (r = 0.48), but not in the H group. The exercise capacity of patients with MI is thought to depend on both the strength and volume of the skeletal muscle. In MI patients with high muscle volume, exercise capacity was determined by skeletal muscle strength alone.