News

AngioJet^® Solent™ Proxi Thrombectomy Catheter

Medrad Interventional (Indianola, Pennsylvania) announces the availability of the Solent Proxi thrombectomy catheter, designed for large, difficult-to-remove thrombus like that found in deep vein thrombosis (DVT). The Solent Proxi joins the growing portfolio of specialized thrombectomy devices available in the AngioJet Ultra System. In response to requests from interventionalists, the Solent Proxi catheter offers the highest clot-removing power in the AngioJet range and is the first to allow swapping of guidewires from the proximal end during the procedure. A second access port with a stopcock has been added to the catheter’s hub to facilitate in situ contrast injection. The Solent Proxi catheter is also constructed with a flexible, polymer-clad spiral shaft and hydrophilic coating on the distal section to improve handling compared to earlier designs.

The Solent Proxi catheter is enabled for Power Pulse Delivery, allowing it to be used to power-infuse lytic into the thrombus. And like all AngioJet thrombectomy catheters, the Solent Proxi catheter is based on the AngioJet Cross-stream^® technology — utilizing high-speed saline jets contained inside the catheter tip to create a powerful low-pressure zone that entrains and removes clot.

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Blood Pressure’s Internally-Driven Daily Rhythm Unlikely to be Linked to Morning Heart Attacks

The internally-driven daily cycle of blood pressure changes doesn’t appear to be linked to the known increase in morning heart attacks, according to a study in Circulation Research: Journal of the American Heart Association.

Researchers sought to identify the role of the internal human body clock in the daily rise and fall in blood pressure. In the study, three groups of volunteers showed an internal daily blood pressure variation with a peak at around 9 pm — independent of changes in activity and other behavioral influences that can affect blood pressure.

Increased blood pressure is a major risk factor for adverse cardiovascular events. However, the study revealed that the internal blood pressure cycle resulted in the lowest blood pressure occurring in the late morning. This unexpected finding indicates that blood pressure’s internal circadian rhythm — a cycle of about 24 hours that occurs in many biological processes — is unlikely to be linked to the well-documented morning peak in heart events or strokes, said Steven A. Shea, PhD, lead author of the study and associate professor of medicine at Harvard Medical School in Boston, Mass.

“We used three complementary experimental protocols and three different groups and found essentially the same results,” Shea said. “That means we’re dealing with something very robust.”

Shea and his colleagues randomized 28 volunteers without hypertension to three multi-day in-laboratory protocols. Before the study, participants maintained a regular sleep-wake schedule at home (16 hours of scheduled wakefulness with eight hours of scheduled sleep) for two to three weeks to stabilize circadian rhythms. They then underwent two baseline days and nights in the laboratory with the same sleep-wake schedule as at home, followed by a prolonged laboratory protocol designed to separate internal circadian effects from behavioral and environmental effects on blood pressure and other physiological variables. These controlled behavioral and environmental conditions included activity, posture, meals, sleep, room temperature, and light. The researchers measured core body temperature to track circadian time. The three protocols, carried out in dim light to avoid resetting any of the body’s circadian rhythms, included:

• 38-hour “constant routine,” with continuous wakefulness and constant body posture.
• 196-hour “forced desynchrony” (forcing a sleep/wake cycle to conflict with participants’ normal pattern) consisting of recurring 28-hour sleep/wake cycles with 18 hours, 40 minutes awake and 9 hours, 20 minutes asleep.
• 240-hour “forced desynchrony” with twelve recurring 20-hour sleep/wake cycles.

All three protocols revealed almost identical systolic and diastolic circadian rhythms, which were unrelated to other internal rhythms that are known to influence cardiovascular events, such as increases in sympathetic nervous system activity.

The reason for the peak in heart attacks and strokes in morning hours remains unexplained by these findings, but could certainly be related to the activities that normally occur on a regular daily basis. “For example, other recent work by our group indicates that the body clock interacts with behaviors, such as exercise, to cause an exaggerated increase in cardiovascular risk markers during the biological morning,” adds Frank A. Scheer, PhD, co-author of the study and assistant professor of medicine at Harvard Medical School. It is possible that the evening peak in the internal circadian blood pressure cycle may help to explain a second, albeit less prominent increase in heart attacks that occurs in the evening, the researchers said.

“We now need to study people with different vulnerabilities and risk factors for cardiovascular disease,” Shea said. “So far, we have studied very healthy people who don’t have hypertension or the build-up of arterial plaques that could bring them closer to the theoretical threshold for precipitating an adverse cardiac event.”

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The Society for Cardiovascular Angiography & Interventions (SCAI) Statement on “The RIVAL Trial: A Randomized Comparison of Radial Versus Femoral Access for Coronary Angiography or Intervention in Patients with Acute Coronary Syndromes”

Patients with acute coronary syndromes who undergo angiography or angioplasty and stent procedures have similar probability of survival whether their arteries are accessed radially or femorally; however, when patients are suffering from a major heart attack, there is significant survival benefit if the heart arteries are accessed radially. The results of the eagerly awaited RIVAL Trial were presented at the American College of Cardiology (ACC) 60th Annual Scientific Sessions.

The RIVAL Trial is the first large North American randomized clinical trial comparing the two options for accessing the heart arteries. The findings are likely to impact practice in the United States because:

• Radial access has now been shown to be a safe and effective technique in North American patients.
• Heart attack patients had a significant survival benefit when they were treated transradially.
• Data corroborate previous studies showing that radial access is preferred by patients.

Importantly, the RIVAL trial results showed that physicians with greater experience using the radial technique had the best outcomes. This finding underscores the need to provide high-quality physician education and training in radial-access heart procedures, as currently only 4.5 percent of coronary procedures in the United States are performed transradially.

SCAI’s Transradial Working Group has developed a series of educational programs for interventional cardiologists to be trained in the use of radial access. The demand for these programs has been high, and SCAI plans to offer at least four programs nationwide in 2011.

“The data from the RIVAL trial are important because they add to the evidence showing that the technique that is more comfortable for patients is also safe and effective,” said Kimberly A. Skelding, MD, FSCAI, at Geisinger Medical Center in Danville, Pa. “These results should provide ample evidence for greater use of the radial option for many minimally invasive cardiovascular tests and procedures, especially in patients suffering from a heart attack.”

“Transradial access has been widely used and accepted in other countries, but has not yet been fully accepted in the U.S.,” said Samir Pancholy, MD, FSCAI, at the Commonwealth Medical College in Scranton, Pa. “The RIVAL Trial shows that our sickest patients will benefit the most if we invest in training physicians to perform the radial technique frequently and safely, hence making it available when patients need it the most.”

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Cardiovascular Systems’ COMPLIANCE 360° Trial Demonstrates Superior Acute Results of the Diamondback 360° over Balloon Angioplasty

Data Presented at the American College of Cardiology Scientific Meeting Shows Superior Procedural Success Rate, with 91 Percent Less Bailout Stenting

Acute data from Cardiovascular Systems’ (CSI) prospective, randomized COMPLIANCE 360° clinical trial was presented at the American College of Cardiology’s (ACC) 60th Scientific Session in New Orleans. The study directly compared the Diamondback 360® Orbital PAD System versus balloon angioplasty in treating above-the-knee peripheral arterial disease (PAD).

COMPLIANCE 360° acute results (ACC i2 Poster #507) showed that the Diamondback 360° Orbital PAD System can achieve far superior acute results in treating calcium-containing femoropopliteal plaque by improving lesion compliance through a technology known as differential sanding, without the need for stent placement.

According to Principal Investigator Dr. Raymond Dattilo, St. Francis Health Center, Topeka, Kan., “The acute data from the COMPLIANCE 360° trial shows treatment with the Diamondback leads to better luminal gain, improved lesion compliance (as reflected in lower balloon pressures post treatment with the Diamondback 360°) and a marked reduction in bailout stenting. The Diamondback’s unique orbital mechanism of action with differential sanding safely removes calcified plaque, reducing the need for high-pressure balloon angioplasty and stenting.”

Acute data showed treatment with the Diamondback 360° generated superior outcomes with fewer complications, as follows in Table 1.

The COMPLIANCE 360° study enrolled 50 patients at nine U.S. sites. All patients had been diagnosed with calcium-containing lesions above the knee with ≥ 70 percent stenosis. Additionally, they exhibited Rutherford class 2 to 4 symptoms, that is, mild to severe pain due to blocked arteries. Patients were equally randomized to two groups: balloon angioplasty alone versus treatment with the Diamondback 360°, followed by low-pressure balloon angioplasty (up to 4 atmospheres), if needed, with the angiographic endpoint of a residual stenosis of ≤ 30 percent without bailout stenting.

COMPLIANCE 360° patients will have clinical follow up at one, six and 12 months, along with duplex scanning and ankle brachial index evaluations.

For more information, visit the company’s website at www.csi360.com.

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Boston Scientific Announces FDA Approval and U.S. Launch of Ion™ Platinum Chromium Stent System

Boston Scientific Corporation announced U.S. Food and Drug Administration (FDA) approval and launch of the Ion™ paclitaxel-eluting platinum chromium coronary stent system, the Company’s third-generation drug-eluting stent technology. The Ion stent system incorporates a platinum chromium (PtCr) alloy designed specifically for coronary stenting and intended to improve the acute performance of coronary stent implantation in the treatment of coronary artery disease.

Louis Cannon, MD, FACC, FACA, Heart and Vascular Institute Program Director at Northern Michigan Regional Hospital in Petoskey, Michigan, said, “The platinum chromium alloy represents a leap forward in materials technology and will address many of the limitations found in older stent alloys. Exceptional stent deliverability offers cardiologists the potential to treat patients with difficult-to-reach lesions.”

The Ion stent offers both monorail^® and over-the-wire versions, with sizes ranging in diameter from 2.25 mm to 4.00 mm and lengths of 8 mm to 38 mm.

Outside the U.S., including CE Mark countries where it was approved in May 2010, the Ion stent system is commercialized as the Taxus® Element™ paclitaxel-eluting coronary stent system. The Ion stent is backed by the proven safety and efficacy of the Taxus clinical program, which spans 10 years of research in nearly 50,000 patients in 28 pre- and post-market studies.

The Ion stent has been evaluated in the PERSEUS trial, which reported 12-month results in March 2010, demonstrating positive safety and efficacy outcomes in workhorse lesions compared to the Taxus Express2^® stent system. The PERSEUS clinical program compared the Ion stent to prior-generation Boston Scientific stents in more than 1,600 patients in two parallel trials at 90 centers worldwide. In April 2011, results from an analysis of pooled patient-level data from 2,298 patients enrolled in the PERSEUS and TAXUS ATLAS clinical trials showed that the Ion stent demonstrated significantly lower rates of major adverse cardiac events, target lesion failure and myocardial infarction compared to the Taxus Liberte® paclitaxel-eluting stent system.

In October 2009, the Company received CE Mark approval for the Promus Element™ everolimus-eluting stent system. The Company anticipates FDA approval for the Promus Element stent system in mid 2012. The product incorporates the same platinum chromium alloy, stent design and catheter delivery system of the Ion stent system. In the U.S., the Promus Element stent system is an investigational device, limited by applicable law to investigational use only and not available for sale.

For more information, please visit: www.bostonscientific.com.

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Unique AED Pads Give Hearts a Second Chance

Rice University, Texas Heart Institute collaborators invent life-saving device

An invention by Rice University bioengineering students in collaboration with the Texas Heart Institute (THI) is geared toward giving immediate second chances to arrhythmia victims headed toward cardiac arrest.

For their capstone design project, a team of Rice seniors created a unique pad system for automated external defibrillators (AEDs), common devices that can shock a victim’s heart back into a proper rhythm in an emergency.

Often, the first shock doesn’t reset a heart and the procedure must be repeated, but the sticky pads on the chest must first be repositioned. The pads need to be in the right location to send current through the heart, and someone with no experience who tries to provide aid might miss the first time.

The Second-Chance AED Pads let rescuers try again without losing valuable time to remove the pads from the victim’s chest. The pads incorporate three electrodes, two in a single pad with an A/B switch attached, and a third in its own pad. 

If one shock doesn’t restart the patient’s heart, flipping the switch will change the jolt’s path, just a little bit, for the second attempt.

The pads were developed by students on the DefibTaskForce — Lisa Jiang, Joanna Nathan, Justin Lin, Carl Nelson and Brad Otto — in tandem with Mehdi Razavi, director of electrophysiology clinical research at THI, and their adviser, Renata Ramos, a Rice lecturer in bioengineering.

The potential for their project was clear from the beginning. “We did some calculations that suggested we could save at least 13,000 lives per year,” Otto said. “Cardiac defibrillation is very time-sensitive. Thirty seconds can be the difference between life and death in a lot of situations. The time it takes to flip the switch is negligible compared with the time it takes to remove the pads, shave and prep a new area on the body, reapply the pads and administer another shock. And a layman might not even know to try a second position.”

Rather than try to build a new type of AED, the team decided early on that it was enough to simply design new pads that would fit devices that are already in use. Manufacturers generally require AED pads be replaced every two years, which provides a ready market for the students’ invention. “But well over 100,000 AED units are produced every year, so even if our pads are only paired with new AEDs, we have a significant market,” Lin said.

Getting the instructions right turned out to be just as important as the device itself and required a lot of illustrative trial and error. In tests for the final version at Rice’s Oshman Engineering Design Kitchen, the team recruited students with no experience using an AED to shock a medical mannequin back to life. “We had 100 percent of the testers place the pads correctly, showing it was very intuitive to use,” Jiang said. 

All five team members, along with Razavi and Ramos, are listed on the provisional patent. They hope an AED manufacturer will pick up the rights to the Second-Chance pads for clinical trials and ultimately FDA approval.

A video of students demonstrating the Second-Chance pads is available at https://www.youtube.com/watch?v=FYChUo1oJM4.

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Abbott’s Absorb Bioresorbable Vascular Scaffold Demonstrates Positive One-Year Safety and Efficacy Results

Abbott announced positive one-year results from 101 patients enrolled in the second phase of the ABSORB trial evaluating a drug-eluting bioresorbable vascular scaffold (BVS) for the treatment of coronary artery disease. These results were presented during the American College of Cardiology’s (ACC) 60th Annual Scientific Session and i2 Summit 2011 in New Orleans.

At one year, Abbott’s Absorb device demonstrated a low 6.9 percent rate of major adverse cardiac events (MACE) and no reports of thromboses. In an analysis of 56 of the 101 patients, imaging results showed a late loss of 0.27 mm, which is comparable to past data on drug-eluting stents. Importantly, of the patients’ vessels that were assessed for vasomotor function, nearly all showed signs of vasomotion (constriction or dilation of the vessel) at one year, indicating that vessel movement was observed in the arteries of these patients as their vessels were no longer constrained by the scaffold, which had begun to be metabolized.

“The one-year data in these patients confirm earlier results seen at the six- and nine-month periods — that the Absorb device has the potential to effectively treat coronary artery disease with the possibility of restoring natural vessel function in a way not possible with permanent metallic implants,” said Patrick W. Serruys, MD, PhD, professor of interventional cardiology at the Thoraxcentre, Erasmus University Hospital, Rotterdam, the Netherlands. “In addition, the one-year late loss seen with Absorb is similar to what has been seen in a historical series of drug-eluting stents, which is an encouraging indication that a bioresorbable scaffold like Absorb might be able to offer the performance capabilities of a metallic drug-eluting stent but with the added benefit of eventually dissolving away.”

Absorb is made of polylactide, a proven biocompatible material that is commonly used in medical implants such as dissolvable sutures. The device is designed to slowly metabolize and eventually be resorbed by the body after providing support to the vessel during the healing process. Absorb received CE Mark in Europe earlier this year and is not approved or available for sale in the United States.

Continuing research will show whether the need to administer long-term dual anti-platelet therapy to patients is necessary once the temporary scaffold is metabolized.

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Treating High Blood Pressure, Cholesterol, Diabetes May Lower Risk of Alzheimer’s Disease

Treating high blood pressure, high cholesterol, diabetes and other vascular risk factors may help lower the risk of Alzheimer’s disease in people who already show signs of declining thinking skills or memory problems. The research is published in the April 13, 2011, online issue of Neurology^®, the medical journal of the American Academy of Neurology.

Researchers followed 837 people with mild cognitive impairment, the stage of memory loss that often leads to Alzheimer’s disease. Of the group, 414 had at least one vascular risk factor. Participants were given blood tests and a medical history questionnaire and also underwent other tests that measured blood pressure, body mass, memory and thinking skills.

Participants who had vascular risk factors were placed into three groups: those with no risk factors treated, those with some risk factors treated and those with all risk factors treated. Treatment of risk factors included using high blood pressure medicines, insulin, cholesterol-lowering drugs and diet control. Smoking and drinking were considered treated if the person stopped smoking or drinking at the start of the study.

After five years, 298 people developed Alzheimer’s disease. The others still had mild cognitive impairment. People with risk factors such as high blood pressure, diabetes, cerebrovascular disease and high cholesterol were two times more likely to develop Alzheimer’s disease than those without vascular risk factors. A total of 52 percent of those with risk factors developed Alzheimer’s disease, compared to 36 percent of those with no risk factors.

Of those with vascular risk factors, people who were receiving full treatment were 39 percent less likely to develop Alzheimer’s disease than those receiving no treatment. Those receiving some treatments were 26 percent less likely to develop the disease compared to people who did not receive any treatment.

“Although this was not a controlled trial, patients who were treated for their high blood pressure, high cholesterol, heart disease and diabetes had less progression of their memory or thinking impairment and were less likely to develop dementia,” said study author Yan-Jiang Wang, MD, PhD, with the Third Military Medical University in Chongqing, China.

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MEETING UPDATE
2011 Cath Lab and Beyond

They came from far and near to attend Sacramento, California’s annual Cath Lab and Beyond training program. This year’s lively group came from cath labs throughout California, Washington, and Arizona. Cath Lab and Beyond, sponsored by Sacramento’s Continuing Education Consortium, is designed specifically for staff new to the cath lab setting. Over 4 1/2 days, in-depth review of cardiac and vascular anatomy, physiology, hemodynamics, pharmacology, and diagnostic and interventional procedures is completed. Hands-on experience with heart dissection, interventional supplies and equipment, and intra-aortic balloon pumps was offered. For more information about Cath Lab and Beyond, go to https://www.continuingeducationconsortium.org/ or call (916) 733-6333.