Measurements of the saturated vapor and liquid densities near the critical point for trans-1,3,3,3-tetrafluoropropene (CFHCHCF3; HFO-1234ze(E)) were carried out in the reduced temperature range of 0.962 < T/T c < 1 and in the reduced density range of 0.40 < ρ/ρc < 1.70. Taking into consideration the meniscus disappearing level as well as the intensity of the critical opalescence, the critical temperature T c and critical density ρc were determined experimentally. The critical pressure P c was calculated by extrapolating the vapor-pressure equation to the critical temperature. The critical parameters reported in this paper are T c = (382.51 ± 0.01) K, ρc = (486 ± 3) kg·m−3, V c = (235 ± 2) cm3·mol−1, and P c = (3632 ± 3) kPa. The saturated liquid density correlation is formulated using the present data. In addition, the critical exponent β along the coexistence curve was also discussed.

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Background Sleep-disordered breathing, particularly central sleep apnea (CSA), is highly prevalent in heart failure (HF) and an independent prognostic marker. We assessed the hypothesis that an increased hypoxemic burden during sleep may have greater prognostic value than the frequency of apneic and hypopneic episodes. Methods and Results We prospectively conducted overnight cardiorespiratory polygraphy on consecutive HF patients referred to our hospital between 2008 and 2011. We studied CSA defined by an apnea-hypopnea index (AHI) of ≥5 events/h, whereby >75% of all events were central in origin. We determined the AHI, proportion of the sleep time with an SpO2<90% (T90%), and percent of the recording time that 4% desaturation events occurred (4%POD). We studied 112 HF patients with either systolic or diastolic dysfunction. During a follow-up period of 37±25 months, 32 patients (29%) died. Non-survivors had a higher 4%POD compared to survivors (11±6.4 vs. 19±13%, p=0.001), but did not differ significantly regarding the AHI and T90% compared to survivors. An adjusted logistic regression analysis revealed that the 4%POD was the best independent predictor of mortality. Conclusion The 4%POD, a novel metric for the nocturnal hypoxemic burden, is an independent prognostic marker in HF patients affected by CSA.

BackgroundAtrial fibrillation (AF) is a significant risk factor for ischemic strokes, and making a robust risk stratification scheme would be important. Few studies have examined whether nonlinear dynamics of the heart rate could predict ischemic strokes in AF. We examined whether a novel complexity measurement of the heart rate variability called multiscale entropy (MSE) was a useful risk stratification measure of ischemic strokes in patients with permanent AF.Methods and ResultsWe examined 173 consecutive patients (age 69±11 years) with permanent AF who underwent 24-hour Holter electrocardiography from April 2005 to December 2006. We assessed several frequency ranges of the MSE and CHA2DS2-VASc score (1 point for congestive heart failure, hypertension, diabetes, vascular disease, an age 65 to 74 years, and a female sex and 2 points for an age≥75 years and a stroke or transient ischemic attack). We found 22 (13%) incident ischemic strokes during a mean follow up of 3.8-years. The average value of the MSE in the very-low frequency subrange (90–300 s, MeanEnVLF2) was significantly higher in patients who developed ischemic strokes than in those who did not (0.68±0.15 vs. 0.60±0.14, P<0.01). There was no significant difference in the C-statistic between the CHA2DS2-VASc score and MeanEnVLF2 (0.56; 95% confidence interval, 0.43–0.69 vs. 0.66; 95% confidence interval, 0.53–0.79). After an adjustment for the age, CHA2DS2-VASc score, and antithrombotic agent, a Cox hazard regression model revealed that the MeanEnVLF2 was an independent predictor of an ischemic stroke (hazard ratio per 1-SD increment, 1.80; 95% confidence interval, 1.17–2.07, P<0.01).ConclusionThe MeanEnVLF2 in 24-hour Holter electrocardiography is a useful risk stratification measure of ischemic strokes during the long-term follow-up in patients with permanent AF.

BackgroundSince warfarin is primarily bound to serum albumin, hypoalbuminemia is likely to increase the free fraction of warfarin and to increase the risk of bleeding. We prospectively evaluated the impact of serum albumin levels (ALB) on international normalized ratio of prothrombin time (PT-INR) control and hemorrhagic events in atrial fibrillation (AF) patients treated with warfarin.MethodsSeven hundred fifty-five non-valvular AF patients on warfarin were enrolled. PT-INR control and major bleeding events (MB, International Society on Thrombosis and Haemostasis) were prospectively followed and were related to ALB at enrollment.ResultsTwenty-seven patients developed MB during 1-year follow-up. In univariate/multivariate analyses, ALB (OR = 0.49, 95% CI 0.26–0.99, p = 0.04) and hemoglobin levels (OR = 0.78, 95% CI 0.65–0.92, p = < 0.01) were predictive for the annual risk of MB. In Spearman's rank correlation analysis, the baseline ALB was inversely correlated with the percentage of the time in PT-INR > 3.0 (ρ = −0.15, p < 0.0001), but neither 2.0 ≤ PT-INR ≤ 3.0 (ρ = 0.056, p = 0.13) nor PT-INR < 2.0 (ρ = −0.008, p = 0.82) during 1-year follow-up, suggesting that patients with low ALB had a directional tendency to be supratherapeutic control of PT-INR. The ROC curve showed that a cutoff of ALB was 3.6 g/dl to identify MB (AUC = 0.65). In Kaplan-Meier analysis, patients with ALB <3.6 g/dl (23/80, 29%) had more MB than those with ALB ≥3.6 g/dl (87/675, 13%, log-rank = 16.80, p < 0.0001) during long-term follow-up (3.8 ± 2.0 years).ConclusionsHypoalbuminemia increases the likelihood of supratherapeutic PT-INR control and the risk of MB. ALB can be a practical surrogate marker to prevent excessive warfarin control and warfarin-related MB.