Tenofovir disoproxil fumarate significantly decreases serum lipoprotein levels compared with entecavir nucleos(t)ide analogue therapy in chronic hepatitis B carriers.

BACKGROUND: Tenofovir disoproxil fumarate (TDF) and entecavir (ETV) are first-line treatments for chronic hepatitis B (CHB). Studies suggest lipid lowering effect of TDF in human immunodeficiency virus positive (HIV+) individuals, but the effect on lipids and cardiovascular disease (CVD) risk in CHB is unknown. AIM: To compare TDF vs ETV effects on lipid levels in CHB. METHODS: In this retrospective cohort study, data on serum lipids and CVD risk factors at baseline and ~1 year on TDF or ETV were collected from CHB carriers. We used propensity score matched models to assess the effect on total cholesterol (TC), LDL-C, HDL and triglycerides (TGL). RESULTS: In 348 patients, median age was 57 (IQR: 47-65 years), 63% were male, 77% were Asian, 19% were cirrhotic, 25% were HBeAg positive at baseline, and 72% received TDF vs 28% ETV. ETV-treated patients were older (median age: 60 vs 55, P<.01), had similar smoking and hypertension rates, but diabetes and dyslipidemia were more prevalent (19% vs 9%, P=.01; 14% vs 6%, P=.05, respectively). In propensity score matched models for age, gender, usage of lipid lowering agents, dyslipidemia and diabetes, TDF-treated patients were more likely to show a 20% decrease in TC (95% CI: 3%-25%), LDL-C (95% CI: 1%-25%) and HDL-C (CI: 10%-30%) levels compared with those on ETV. No change in TGL was observed in either group. CONCLUSIONS: A greater decline in TC, LDL-C and HDL was observed in CHB carriers receiving TDF compared with ETV. These data may influence anti-viral choice in CHB carriers at risk for CVD.

Incidence of bleeding complications associated with abciximab use in conjunction with thrombolytic therapy in patients requiring percutaneous transluminal coronary angioplasty.

The use of abciximab after full-dose failed thrombolytics within 15 hours of acute myocardial infarction significantly increases the risk of major bleeding complications.

High resolution imaging of in vivo cardiac dynamics using color Doppler optical coherence tomography.

Color Doppler optical coherence tomography (CDOCT) is a noninvasive technique for simultaneous high spatial resolution (~20 aem) imaging and high velocity resolution (~500 aem/s) imaging flowmetry in living tissues. In this paper, we demonstrate a reconstruction method which overcomes fundamental limitations on Doppler flow mapping associated with both high- and low-speed imaging. This algorithm is successful in retaining the high velocity resolution of CDOCT while eliminating motion artifact caused by slow image acquisition in samples which exhibit repetitive motion. We demonstrate reconstruction of blood flow throughout a beating Xenopus laevis heart and surrounding vasculature using gated CDOCT reconstruction.

In vivo video rate optical coherence tomography.

An optical coherence tomography system is described which can image up to video rate. The system utilizes a high power broadband source and real time image acquisition hardware and features a high speed scanning delay line in the reference arm based on Fourier-transform pulse shaping technology. The theory of low coherence interferometry with a dispersive delay line, and the operation of the delay line are detailed and the design equations of the system are presented. Real time imaging is demonstrated in vivo in tissues relevant to early human disease diagnosis (skin, eye) and in an important model in developmental biology (Xenopus laevis).

Iatrogenic arteriovenous fistula: a complication of percutaneous subclavian vein puncture.

A case of iatrogenic subclavian arteriovenous fistula is reported. An intracath had been inserted percutaneously into the left subclavian vein to monitor the central venous pressure during aortic valve surgery. On the second postoperative day a thrill and continuous murmur were detected at the left subclavian region. Left subclavian arteriogram and catheterization studies confirmed the diagnosis of subclavian arteriovenous fistula. The lesion was treated surgically with satisfactory results.

Real-time optical coherence tomography of the anterior segment at 1310 nm.

BACKGROUND: Recent advances in high-speed scanning technology have enabled a new generation of optical coherence tomographic (OCT) systems to perform imaging at video rate. Here, a handheld OCT probe capable of imaging the anterior segment of the eye at high frame rates is demonstrated for the first time. OBJECTIVE: To demonstrate real-time OCT imaging of anterior segment structures. DESIGN: Survey of anterior segment structures in normal human subjects. SETTING: Laboratory. MAIN OUTCOME MEASURES: Achieving real-time imaging of the anterior segment, satisfactory image quality, and convenience of a handheld probe. RESULTS: Optical coherence tomographic imaging of the anterior segment of the eyes of human subjects was performed using 1310-nm wavelength light with an image rate of 8 frames per second. Imaging trials demonstrated clear resolution of corneal epithelium and stroma, sclerocorneal junction, sclera, iris pigment epithelium and stroma, and anterior lens capsule. The anterior chamber angle was clearly visualized. Limited imaging of the ciliary body was performed. Real-time imaging of pupillary constriction in response to light stimulus was also performed. CONCLUSION: High-speed OCT at 1310-nm wavelength is a potentially useful technique for noninvasive assessment of anterior segment structures. CLINICAL RELEVANCE: Our results suggest that real-time OCT has potential applications in glaucoma evaluation and refractive surgery.

Preliminary evaluation of cocarboxylase on myocardial protection of the rat heart.

The presence of cocarboxylase (CC) is essential for the oxidation of pyruvate to acetylcoenzyme A (acetyl-CoA) and its subsequent degradation by means of the Krebs cycle. We compared the effects of various concentrations of CC in a cardioplegic solution on the survival and hemodynamic and metabolic recovery of 23 isolated, working rat hearts subjected to 60 minutes of hypothermic (23 degrees C) ischemic arrest. Group 1 (N = 6) consisted of hearts infused with the basic cardioplegic solution (Tyers' solution with glucose), to which no CC was added. In group 2 (N = 6) CC was added at 0.1 ml/L to the cardioplegic solution. In group 3 (N = 5) CC was added at 1 ml/L, and in group 4 (N = 6) CC was added at 10 ml/L. The cardioplegic infusions were performed at a pressure of 40 mm Hg for 2 minutes just before arrest; 30 minutes later they were performed again for 1 minute. Only two hearts (33.3%) recovered in group 1 whereas five recovered in group 2, five (100%) in group 3, and five (83.3%) in group 4. The recovery of hemodynamic performance as a percentage of preischemic control values showed marked improvement in the CC groups, especially group 3, when compared with group 1. The metabolic variables in the CC groups were also markedly improved, with significantly (p less than .05) decreased levels of tissue lactate and increased levels of creatine phosphate compared with those in group 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Photothermal coagulation of blood vessels: a comparison of high-speed optical coherence tomography and numerical modelling.

Optical-thermal models that can accurately predict temperature rise and damage in blood vessels and surrounding tissue may be used to improve the treatment of vascular disorders. Verification of these models has been hampered by the lack of time- and depth-resolved experimental data. In this preliminary study, an optical coherence tomography system operating at 4-30 frames per second was used to visualize laser irradiation of cutaneous (hamster dorsal skin flap) blood vessels. An argon laser was utilized with the following parameters: pulse duration 0.1-2.0 s, spot size 0.1-1.0 mm, power 100-400 mW. Video microscopy images were obtained before and after irradiations, and optical-thermal modelling was performed on two irradiation cases. Time-resolved optical coherence tomography and still images were compared with predictions of temperature rise and damage using Monte Carlo and finite difference techniques. In general, predicted damage agreed with the actual blood vessel and surrounding tissue coagulation seen in images. However, limitations of current optical-thermal models were identified, such as the inability to model the dynamic changes in blood vessel diameter that were seen in the optical coherence tomography images.

High risk percutaneous transluminal coronary angioplasty in the treatment of severe coronary artery disease.

We report on 27 "high risk" patients out of 171 consecutive patients undergoing percutaneous transluminal coronary angioplasty from June 1984 to August 1985. The ages ranged from 31-80 years (mean 62.7 +/- 10) years. High risk percutaneous transluminal coronary angioplasty was defined as: salvage cases (3 patients) where the patients presented in cardiogenic shock or the vessels were not bypassable; multivessel coronary artery disease (22 patients) where a large area of jeopardized myocardium was dependent on the angioplasty vessel(s); left ventricular dysfunction (7 patients) as defined by two of the three criteria: left ventricular end-diastolic volume index greater than 100 ml/m2; ejection fraction less than 30%; and left ventricular end-diastolic pressure greater than 20 mm Hg. The initial success rate in the high risk patients was 85.2%. Emergency coronary artery bypass surgery in these patients was 7.4%. There was one death in the high risk group, as one of the salvage cases died 24 hours after successful percutaneous transluminal coronary angioplasty due to severe underlying myocardial disease. In conclusion percutaneous transluminal coronary angioplasty can be successfully performed in high risk patients with a low complication rate and should be considered as an alternative to coronary artery bypass graft surgery in selected high risk patients.

Beneficial effects of cocarboxylase in the treatment of experimental myocardial infarction in dogs.

Cocarboxylase, or thiamine pyrophosphate, is an essential coenzyme in the catabolism of pyruvate. The authors evaluated the effects of a stable cocarboxylase solution in the treatment of an experimentally created acute myocardial infarction in 14 healthy mongrel dogs. The left anterior descending artery was ligated for 60 minutes and data were collected at the following points: A) prior to ligation, B) 15 minutes after ligation, C) 30 minutes after ligation, and D) 60 minutes after ligation. In one group (Group II), cocarboxylase (150 mgm/kg) was given systematically via a central line 15 minutes and 45 minutes after ligation, while in Group I an equal amount of D5W was given. Hemodynamic data include heart rate, systolic and mean arterial pressure, pulmonary wedge pressure, right arterial pressure, and cardiac output. Myocardial O2 consumption was determined by the method of Rooke and Feigl. Electrocardiographic data were also monitored throughout the experiment. In both groups, preligation (point A) hemodynamic data were similar. In Group II, there were beneficial hemodynamic changes versus Group I (expressed as percentage recovery of hemodynamic performance from preligation) at points C and D, with significant (P less than 0.05) decreases in heart rate, increased stroke volume, decreased systemic vascular resistance, and decreased myocardial O2 consumption. EKG criteria also showed improvement in Group II versus Group I. In conclusion, this experiment suggests that cocarboxylase may be beneficial to ischemic canine myocardium by virtue of its favorable systemic hemodynamic effects.

Iatrogenic postoperative left ventricular outflow tract obstruction.

A 56-year-old female, who underwent aortocoronary bypass graft for occlusion of anterior descending artery is reported, who postoperatively developed a harsh systolic murmur, mitral regurgitation, and intraventricular systolic pressure gradient suggestive of hypertrophic subaortic stenosis. The above findings were due to the administration of dobutamine hydrochloride for hypotension in association with afterload reduction (intra-aortic balloon pumping) and disappeared almost immediately after left ventriculography (volume load).

Coronary dissection and thrombosis associated with exercise testing three months after successful coronary stenting.

Exercise testing is commonly performed to assess the functional result of coronary revascularization procedures and is usually not associated with any complications. However, this report documents a rare case of coronary dissection and thrombosis, which resulted in an acute myocardial infarction, in a patient who underwent stress testing 3 months following successful coronary stent implantation.

Directional coronary atherectomy in women compared with men.

The influence of gender on the procedural outcome of directional coronary atherectomy (DCA) is controversial. This study of 373 consecutive patients (418 lesions) undergoing DCA demonstrates that the procedural success rate of DCA is significantly lower in women compared with men (72.7 vs. 82.9%, p = 0.011). Women have significantly smaller coronary arteries than men (2.5 mm vs. 2.7 mm, p = 0.028) and were older than men (66 vs. 61 years, p = 0.0001). Multivariate analysis identifies small coronary vessel size rather than female gender per se as an independent predictor of poor procedural outcome. Procedural success rates in women with coronary vessel size > or = 2.5 mm is significantly higher (92.2%) than in women with coronary vessel size < 2.5 mm (73.1%), and parallels that in men with vessel size > or = 2.5 mm (89.3%). Inability to engage the ostium of the coronary artery adequately with the guiding catheter and to cross the lesion with the atherectomy device is significantly more common in women compared with men. Major ischemic complication rates are similar in women and men (8.5 vs. 8.7%). Groin complications are significantly more common in women compared with men (13.5 vs. 2.9%). We conclude that procedural success rates in women may be improved by careful patient selection, with particular attention to small vessel size. DCA is best performed in vessels > 2.5 mm in diameter.

Hypoxia due to patent foramen ovale in the absence of pulmonary hypertension.

In most patients with a patent foramen ovale, blood flows from the left atrium to the right atrium in the absence of pulmonary hypertension. Our report describes a patient with a patent foramen ovale in whom flow occurred from the right atrium to the left atrium in the absence of pulmonary hypertension. We discuss hemodynamic findings and present a brief review of the pertinent medical literature regarding this phenomenon. We also discuss the role of transesophageal echocardiography in the diagnosis of this condition and in the elucidation of the underlying mechanisms, and we suggest several mechanisms that may explain the occurrence of this phenomenon in our patient.

Ergonovine provocative testing: description of a "double catheter technique".

Since coronary arteries should be immediately accessible during ergonovine provocative testing (EPT), a double catheter technique is described. Using the catheter sheath technique from the right and left femoral arteries, right and left Judkins' catheters are introduced into each femoral artery. Selective coronary cineangiography during EPT is thus rapidly performed without the delay of exchanging catheters. Should coronary arterial spasm occur during the test, nitroglycerin can be administered into the coronary artery without delay.

Guide catheter exchange techniques: bi-coaxial and other methods.

Maintaining the position of a guidewire across coronary artery lesions during angioplasty is important to allow rapid and reliable access. Stabilizing these small caliber angioplasty guidewires during guide catheter replacement is often difficult, if not impossible at times. This article reviews the techniques for exchanging guide catheters while maintaining coronary guidewire position. It also introduces the bi-coaxial guide catheter exchange technique.

Imaging and velocimetry of the human retinal circulation with color Doppler optical coherence tomography.

Noninvasive monitoring of blood flow in retinal microcirculation may elucidate the progression and treatment of ocular disorders, including diabetic retinopathy, age-related macular degeneration, and glaucoma. Color Doppler optical coherence tomography (CDOCT) is a technique that allows simultaneous micrometer-scale resolution cross-sectional imaging of tissue microstructure and blood flow in living tissues. CDOCT is demonstrated for the first time in living human subjects for bidirectional blood-flow mapping of retinal vasculature.