Low‐Dose Heparin for Elective Percutaneous Coronary Intervention

Objectives

We evaluated the safety and efficacy of low‐dose heparin (40 IU/kg) for elective percutaneous coronary intervention (PCI).

Background

Current guidelines recommend a 70–100 IU/kg bolus of heparin for elective PCI, but this dose may be associated with increased bleeding risk. Low‐dose heparin may have an advantage in this regard, but has not been well studied.

Methods

From January 2008 to October 2012, 300 patients underwent elective transfemoral PCI and were treated with an initial bolus of 40 IU/kg of heparin at the UCLA Medical Center. Dual antiplatelet therapy with clopidogrel and aspirin was administered prior to or just after diagnostic coronary angiography. The primary end‐point was the composite of cardiac death, myocardial infarction, urgent target vessel revascularization for ischemia, or major bleeding within 30 days after PCI.

Results

The mean activating clotting time was 233 ± 28 seconds. The primary end‐point occurred in 2.3%. The cardiac death rate was 0.3% but was not related to the PCI. The myocardial infarction rate was 1.3%. Urgent target vessel revascularization occurred in 1 patient (0.3%). The major bleeding rate was 0.3%. No stent thrombosis occurred.

Conclusion

Using a lower dose of heparin with dual antiplatelet therapy is safe and is associated with a low bleeding risk after transfemoral PCI while providing suppression of ischemic events. This may also represent a cost savings compared with other antithrombotic strategies. A randomized clinical trial comparing low‐dose heparin with bivalirudin in patients is required to determine the optimal anticoagulation strategy. (J Interven Cardiol 2014;27:58–62)

     

POWER CALCULATION FOR A SCORE TEST IN THE DEPENDENT CENSORING MODEL

We propose a method for testing the assumption of independent censoring in right censored survival data. This method includes extra data collection by the subsequent follow-up of a subset of censored subjects. A score test statistic is derived within the framework of a Cox proportional hazards model with a time-dependent covariate. In this paper we focus on the power calculation for the score test under proportional hazards alternatives. Comparison of the observed with the theoretical power shows that the latter is somewhat lower than the former.     

TWO SAMPLE COMPARISON FOR LARGE GROUPS OF CORRELATED BINARY RESPONSES

Although there is much literature on testing the treatment effect in experiments with correlated binary outcomes, the existing methodologies only work well when the cluster size is small. In this paper, I propose a simple method to test the treatment effect in experiments with large groups of correlated binary outcomes. I use the weighted estimating equations approach to estimate the treatment effect. The proposal is appropriate under any correlation structure. Power comparisons show the advantage of the new procedure.     

Left Septal Atrial Tachycardias: Electrocardiographic and Electrophysiologic Characterization of a Paraseptal Focus

Left Septal Atrial Tachycardias. Objective: The objective was to characterize the electrocardiographic and electrophysiological features of focal atrial tachycardia (FAT) originating from the left septum (LS). Background: FAT is recognized to occur at predefined anatomic locations rather than randomly throughout the atria. We describe the ECG and EP features of ATs originating from the LS as an important site for apparent perinodal tachycardias. Methods: Nine patients presenting with LS FAT from a consecutive series of 384 underwent EP/RFA for symptomatic FAT. Results: The mean age was 56 ± 12 years; 7 female with symptoms for 36 ± 28 months. P wave morphology (PWM) was negative/positive in lead V1 and across the precordial leads and negative or negative/positive in inferior leads in all patients. Tachycardia was incessant in 6 out of 9 patients with a mean tachycardia cycle length 421 ± 56 milliseconds. His A was ahead of P wave in all patients (mean ?15 ± 5 milliseconds) and earlier than CS proximal (mean 4 ± 9 milliseconds). Successful acute focal ablation achieved at a mean of 31 ± 12 milliseconds ahead of P wave with no recurrences at a mean follow‐up of 30 ± 28 months. Conclusion: Although the left septum is an uncommon site for focal AT an awareness of this location for harboring foci is particularly important when mapping apparently right‐sided septal tachycardias. (J Cardiovasc Electrophysiol, Vol. 24, pp. 413‐418, April 2013)     

14-3-3σ负调控Akt抑制Rat1-Akt细胞成瘤性

目的:研究腺病毒介导14-3-3·σ（Ad-14-3-3·σ）对Akt过表达Rat1-Akt细胞成瘤性的作用，并探讨其作用是否通过负调控Akt而实现。 方法:通过半体内和体内实验观察Ad-14-3-3·σ转染对Rat1-Akt细胞在裸鼠中成瘤性的影响；采用Western blotting方法检测转染14-3-3·σ基因后肿瘤组织内14-3-3·σ蛋白及其对Akt蛋白、Akt磷酸化活性和Akt磷酸化底物水平的影响。 结果:无论体外用Ad-14-3-3σ处理Rat1-Akt细胞，还是体内经瘤内注射Ad-14-3-3σ，均可见14-3-3·σ可使荷瘤鼠肿瘤体积显著缩小（P＜0.05）,出现肿瘤的时间推迟，其中以长时间不间断给药疗效最好；转染14-3-3·σ基因治疗组的肿瘤组织中Akt蛋白、Akt-Thr308位点磷酸化活性及Akt磷酸化底物水平低于转染Ad-β-gal或PBS处理的对照组。 结论:14-3-3σ可抑制Rat1-Akt细胞在裸鼠中的成瘤性，14-3-3σ通过负性调控Akt蛋白水平和磷酸化活性而抑瘤。     

音乐对机械通气患者生理与焦虑状态的影响

目的观察音乐对机械通气患者的心率(HR)、呼吸频率(RR)、血压(Bp)及焦虑程度的影响.方法将64例机械通气患者随机分为30min音乐治疗组与对照组.研究前后,以中国人状态特性焦虑量表(C-STAI)对两组患者分别进行测试,同时记录HR、RR、Bp以及休息状态.结果与对照组相比,音乐组HR(-3.8±7.0,P= 0.009)和RR (-3.6±4.9,P<0.001)下降更快.音乐可以显著降低患者的HR、RR、收缩压和舒张压 (P均<0.005).音乐组患者的焦虑得分比对照组降低,但差异无统计学意义.音乐组患者的舒适行为比对照组多.结论音乐可以明显改善机械通气患者的生理状态,减轻焦虑反应.