Malcolm T. Foster

Reversal of “no reflow” during vein graft stenting using high velocity boluses of intracoronary adenosine

Slow or no reflow is a serious problem complicating catheter-based revascularization of degenerated saphenous vein bypass grafts. We examined the efficacy of rapidly delivered, high-velocity injections of intracoronary adenosine to reverse 11 slow-flow events complicating stenting of diseased bypass grafts. Ten of 11 events were rapidly improved to TIMI 3 flow by this technique within 3.8+/-1.6 min of the initial adenosine injection. In an ex vivo model, 3-ml syringes created higher peak pressures and velocities than 10- and 20-ml syringes. We conclude that rapid and repeated high-velocity intragraft administration of adenosine is a promising new approach to promptly reverse no-reflow events complicating PTCA and stenting of diseased saphenous vein grafts. Ex vivo studies demonstrate a potentially important mechanical advantage with the use of small syringes for injection. Further randomized studies will be required to better define the mechanism(s) and efficacy of this approach for treating no reflow, including its use in native vessels.

Group A Beta-Hemolytic Streptococci Resistant to Erythromycin and Lincomycin

Abstract In a 17-month-old girl an upper-respiratory-tract infection acutely developed. Group A beta-hemolytic streptococci were found on throat culture. She was treated with erythromycin. No clini...

Mapping Brain c‐Fos Immunoreactivity after Insulin‐Induced Voluntary Lard Intake: Insulin‐ and Lard‐Associated Patterns

In addition to the inhibitory role of central insulin on food intake, insulin also acts to promote lard intake. We investigated the neural pathways involved in this facet of insulin action. Insulin or saline was infused into either the superior mesenteric or right external jugular veins of streptozotocin‐diabetic rodents with elevated steady‐state circulating corticosterone concentrations. After postsurgical recovery, rats were offered the choice of chow or lard to eat. Irrespective of the site of venous infusion, insulin increased lard and decreased chow intake. After 4 days, lard was removed for 8 h. On return for 1 h, only insulin infused into the superior mesenteric vein resulted in lard intake. This facilitated distinction between the effects of circulating insulin concentrations (similar in the two insulin‐infused groups) and lard ingestion on the patterns of c‐Fos+ cells in the brain, termed insulin‐ and lard‐associated patterns, respectively. Insulin‐associated changes in c‐Fos+ cell numbers were evident in the arcuate nucleus, bed nucleus of the stria terminalis and substantia nigra pars compacta, concomitant with elevated leptin levels and reduced chow intake. Lard‐associated changes in c‐Fos+ cell numbers were observed in the nucleus of the tractus solitarius, lateral parabrachial nucleus, central nucleus of the amygdala, ventral tegmental area, nucleus accumbens shell and the prefrontal cortex, and were associated with lower levels of triglycerides and free fatty acids. The anterior paraventricular thalamic nucleus exhibited both patterns. These data collectively fit into a framework for food intake and reward and provide targets for pharmacological manipulation to influence the choice of food intake.

Carotid artery stenting with emboli protection surveillance study: outcomes at 1 year.

OBJECTIVES The CASES-PMS (Carotid Artery Stenting With Emboli Protection Surveillance-Post-Marketing Study) multicenter, prospective, single-arm, surveillance study was designed to assess the safety and efficacy of carotid artery stenting (CAS) when performed by physicians with varied experience in CAS utilizing a formal training program. Whether the excellent results achieved at 30 days would be sustained to 1 year was the subject of the current investigation. BACKGROUND Previously, the pivotal SAPPHIRE (Stenting and Angioplasty with Protection of Patients with High Risk for Endarterectomy) trial demonstrated that CAS was not inferior to carotid endarterectomy (CEA) when performed by physicians experienced in carotid stenting. METHODS High surgical-risk patients with de novo atherosclerotic or post-endarterectomy restenotic lesions in native carotid arteries were enrolled at participating centers. Inclusion and exclusion criteria matched those of the SAPPHIRE trial. The primary end point was a composite of 30-day major adverse events (MAE) including death, any stroke, or myocardial infarction. RESULTS A total of 1,492 patients were enrolled at 73 sites. The primary end point of 30-day MAE was 5.0%, meeting criteria for noninferiority to the prespecified objective performance criteria (OPC) established by the SAPPHIRE trial. The 1-year cumulative percentage of MAE was 12.5% by Kaplan-Meier analysis. All strokes to 30 days plus ipsilateral stroke between 31 and 360 days with CASES-PMS (5.4%) was similar to the rate seen with the SAPPHIRE trial stent cohort (4.9%). There were no significant differences in outcomes at 1 year by symptom status and high-risk status. CONCLUSIONS With the formalized training program utilized in this study, physicians with varied experience in carotid stenting can achieve similar short- and longer-term results to the highly experienced SAPPHIRE Investigators. (Carotid Artery Stenting With Emboli Protection Surveillance-Post-Marketing Study [CASES-PMS]; NCT00231231).

The State of the Absorb Bioresorbable Scaffold: Consensus From an Expert Panel

Significant progress has been made in the percutaneous coronary intervention technique from the days of balloon angioplasty to modern-day metallic drug-eluting stents (DES). Although metallic stents solve a temporary problem of acute recoil following balloon angioplasty, they leave behind a permanent problem implicated in very late events (in addition to neoatherosclerosis). BRS were developed as a potential solution to this permanent problem, but the promise of these devices has been tempered by clinical trials showing increased risk of safety outcomes, both early and late. This is not too dissimilar to the challenges seen with first-generation DES in which refinement of deployment technique, prolongation of dual antiplatelet therapy, and technical iteration mitigated excess risk of very late stent thrombosis, making DES the treatment of choice for coronary artery disease. This white paper discusses the factors potentially implicated in the excess risks, including the scaffold consideration and deployment technique, and outlines patient and lesion selection, implantation technique, and dual antiplatelet therapy considerations to potentially mitigate this excess risk with the first-generation thick strut Absorb scaffold (Abbott Vascular, Abbott Park, Illinois). It remains to be seen whether these considerations together with technical iterations will ultimately close the gap between scaffolds and metal stents for short-term events while at the same time preserving options for future revascularization once the scaffold bioresorbs.

A pilot study of chronic recombinant interferon-alfa 2a for diabetic proliferative retinopathy: metabolic effects and opthalmologic effects.

The objective of this study was to evaluate the metabolic effects and opthalmologic effects of alpha-interferon therapy in diabetes mellitus patients with proliferative diabetic retinopathy (PDR). Three volunteer patients [insulin-dependent diabetes mellitus (IDDM), insulin requiring non-insulin-dependent diabetes mellitus (NIDDM), and maturity onset diabetes of the young (MODY)] threatened with blindness due to progressive PDR were treated with alpha interferon for 4 months and were evaluated at intervals of 1-2 weeks to monitor the drug effects on carbohydrate tolerance and possible beneficial therapeutic effects on the preexisting PDR. Metabolic studies included basal and postsustacal glucose, c-peptide and glucagon, fasting serum cortisol, free fatty acids, growth hormone, insulin-like growth factor-1, and urinary microalbumin excretion. Ophthalmologic studies included visual acuity, slit lamp examination, gonioscopy, fluorescein angiography, and standard colored fundus photographs. In all subjects, hyperglycemia worsened with duration of increasing dosage of interferon therapy, requiring progressively higher daily insulin requirements of 17%-68% above pretreatment values. Lowered levels of stimulated C-peptide were observed in the NIDDM and MODY subjects. The counterregulatory hormones (cortisol, growth hormone, and glucagon) were elevated during the 4 months of interferon therapy. In all subjects, visual acuity appeared to stabilize. No new retinal hemorrhages occurred during the 4 months of interferon administration, although all subjects experienced hemorrhage within 6 weeks of termination of the drug. Although only three subjects were investigated, the 1-2 week frequency of metabolic and opthalmologic studies permit some conclusions. The metabolic effects of alpha interferon in our diabetic subjects were consistent worsening of carbohydrate tolerance associated with impaired beta-cell secretion and increased insulin resistance. The extensive opthalmologic investigation suggested protection from retinal hemorrhage while receiving interferon, but further studies are indicated to validate these proposed and antiangiogenic properties.

Insulin and the Constituent Branches of the Hepatic Vagus Interact to Modulate Hypothalamic and Limbic Neuropeptide mRNA Expression Differentially

Insulin and signalling through the vagus nerve act in concert to regulate metabolic homeostasis and ingestive behaviour. Our previous studies using streptozotocin (STZ)‐diabetic rats have shown that hepatic branch vagotomy (HV), gastroduodenal branch vagotomy (GV) and capsaicin treatment of the common hepatic branch that selectively destroys afferent fibres (CapV), all promote lard, but not total, caloric intake to levels similar to those achieved with insulin treatment. Because hypothalamic and limbic mRNA expression of neuropeptides linked to energy balance is altered by STZ‐diabetes and HV, we examined the role(s) of insulin and the common hepatic and gastroduodenal branches of the vagus nerve and hepatic afferent fibres in the regulation of these neuropeptides in rats with high, steady‐state corticosterone levels. STZ‐diabetic rats were prepared with osmotic minipumps containing either saline or insulin and were compared with nondiabetic counterparts: half of each group received a vagal manipulation, the other half were sham operated. Five days after surgery, rats were offered the choice of lard and chow to consume for another 5 days, when brains were collected and processed for in situ hybridisation. Paraventricular nucleus corticotrophin‐releasing factor (CRF) mRNA was elevated by STZ treatment, an effect prevented by either insulin treatment or GV. By contrast, CRF mRNA expression in the central nucleus of the amygdala and bed nuclei of the stria terminalis was unaffected by STZ treatment, but HV and CapV manipulations elevated expression in the nondiabetic, but not STZ‐diabetic groups. Arcuate nucleus neuropeptide Y, but not pro‐opiomelanocortin, mRNA expression was elevated by STZ treatment and all vagal manipulations; however, exogenous insulin treatment failed to prevent this, in keeping with their previously documented elevated caloric intake. These results strongly suggest that the gastroduodenal branch and hepatic branch proper, which merge to form the common hepatic branch, differentially interact with prevailing insulin levels to regulate hypothalamic and limbic neuropeptide mRNA expression.

Carotid artery stenting and patient outcomes: The CABANA surveillance study

The purpose of the prospective, multicenter, nonrandomized CABANA study was to evaluate periprocedural clinical outcomes in high surgical risk patients with carotid artery stenosis treated with the Carotid WALLSTENT plus FilterWire EZ Embolic Protection System by a diverse group of clinicians.

Electrophysiologic effects and predictors of success of combination therapy with class Ia and Ib antiarrhythmic drugs for sustained ventricular arrhythmias.

Antiarrhythmic drugs remain the first line of therapy in patients with sustained ventricular arrhythmias. Although success with class Ia antiarrhythmic medications has been limited, there is evidence that the addition of a class Ib agent may improve results. A total of 110 consecutive patients referred for electrophysiologic evaluation who had inducible sustained ventricular arrhythmias resistant to a class Ia agent underwent repeat electrophysiologic study after the addition of a class Ib drug. Patients with ejection fraction >40% and ventricular fibrillation inducible in the baseline study had an 80% response rate, whereas those with inducible ventricular tachycardia and ejection fraction < or = 40% responded 11% of the time. Responders demonstrated marked prolongation of ventricular refractoriness and slight shortening of the QRS, whereas nonresponders had QRS prolongation and a more modest increase in ventricular refractoriness. Thus, the efficacy of class Ia/Ib combination therapy in patients with inducible sustained ventricular arrhythmias refractory to a class Ia drugs alone can be predicted by baseline variables. Marked prolongation of ventricular refractoriness in the absence of QRS prolongation appears to be a key factor in the success of this combination.

Ultrasound thrombolysis for the treatment of thrombotic occlusion of degenerated saphenous vein grafts.

Despite improvements in catheter‐based revascularization outcomes, coronary interventionalists face difficult challenges in the treatment of the thrombus‐laden coronary lesion. In this report, we describe the use of the Acolysis device, which utilizes high‐frequency (41.9 kHz) ultrasonic energy to vibrate a small metal tip at the end of a 4.5 Fr catheter to treat two thrombotically occluded saphenous vein grafts in two patients. In both cases, the Acolysis device provided normalization of flow with angiographically evident dissolution of thrombus and excellent acute angiographic and clinical results. We conclude that in these two selected cases the Acolysis device was used safely and effectively for thrombus debulking as an adjunct to stenting in diseased saphenous vein bypass grafts. Cathet. Cardiovasc. Intervent. 50:90–95, 2000.