A Medical Device Daily

Abbott (Abbott Park, Illinois) reported three-year data from the first 30 patients in the first phase of the ABSORB clinical trial, demonstrating that its fully bioabsorbable drug eluting coronary stent successfully treated coronary artery disease and was absorbed into the walls of treated arteries. These results were presented at the American Heart Association's (AHA; Dallas) Scientific Sessions in Orlando.

Patients in this first phase of the ABSORB trial experienced no stent thrombosis (blood clots) out to three years and no new major adverse cardiac events (MACE) between six months and three years (3.6% at three years), Abbott reported.

To build upon the promising results of the ABSORB trial, Abbott said it is initiating a large-scale trial called ABSORB EXTEND, which will enroll about 1,000 patients from up to 100 centers in Europe, Asia Pacific, Canada and Latin America. ABSORB EXTEND is a single-arm study designed to further evaluate the performance of Abbott's fully bioabsorbable stent technology. The study will enroll patients with more complex coronary artery disease and is slated to begin enrolling before the end of the year, the company said.

"Abbott's bioabsorbable stent has the potential to be a major breakthrough for coronary artery disease patients. The data show that patients continue to do well three years after treatment with the bioabsorbable coronary stent," said Patrick Serruys, MD, PhD, professor of interventional cardiology at the Thoraxcentre, Erasmus University Hospital (Rotterdam, the Netherlands), and principal investigator for the ABSORB trial. "The strong results confirm my belief that bioabsorbable technology is the next revolution in interventional cardiology."

Abbott also reported that patient enrollment is complete for the second phase of the ABSORB trial. The second phase of the trial enrolled 101 additional patients from 12 centers in Europe, Australia and New Zealand, and incorporated device enhancements designed to improve deliverability and vessel support, the company noted.

According to Abbott it is the only company with three-year clinical data evaluating the safety and performance of a fully bioabsorbable drug eluting coronary stent. Abbott's bioabsorbable everolimus eluting coronary scaffold is made of polylactide, a proven biocompatible material that is commonly used in medical implants such as absorbable sutures. As with a metallic coronary stent, Abbott's bioabsorbable technology is designed to restore blood flow by propping open a clogged vessel, and to provide support until the blood vessel heals. Unlike a metallic stent, however, a bioabsorbable scaffold is designed to be slowly metabolized by the body and is completely absorbed over time, the company said.

"Abbott continues to make advancements with its promising bioabsorbable technology," said Charles Simonton, MD, divisional VP of Medical Affairs, and chief medical officer at Abbott Vascular. "The second phase of the ABSORB trial enrolled very quickly, which is a testament to the excitement among the clinical community around the potential shown with this technology. We look forward to starting the ABSORB EXTEND trial to further evaluate promising attributes of our fully bioabsorbable technology in a broader patient population."

In other AHA news:

• Researchers reported in a late-breaking clinical trial presentation that a new, continuous flow heart pump, or left ventricular assist device (LVAD), delivered better two-year survival in advanced heart failure patients than the current pulsatile model.

In the HeartMate II Destination Therapy Trial, researchers tested a new device that helped heart failure patients who weren't responding to optimal medical therapy and weren't eligible for a heart transplant. They found significant improvement in outcomes of patients who received the continuous flow LVAD (HeartMate II) compared to those who received a pulsatile flow LVAD (HeartMate XVE), the only FDA-approved device for treating such patients.

Thoratec (Pleasanton, California) funded the researchers.

The study included 200 end-stage heart failure patients implanted at 38 U.S. medical centers between March 2005 and May 2007. All patients had failed optimal medical therapy and were ineligible for a heart transplant, according to the study.

The primary endpoint was survival free from disabling stroke and device failure requiring re-operation at two years. Secondary endpoints included overall survival, adverse events, quality of life and functional capacity

Researchers said a greater proportion of continuous flow LVAD patients successfully reached the primary composite end-point compared to pulsatile flow (46% vs. 11%).

At one-year follow-up, 68% of the continuous flow LVAD patients had survived compared to 55% in the pulsatile flow group. At two years, survival was 58% for the continuous flow device vs. 24% with the pulsatile device.

The researchers also noted that 10% of the patients who received the continuous flow LVAD needed surgery to repair or replace the pump compared to 36% of patients with the pulsatile device.

The HeartMate II was approved for bridge-to-transplantation (BTT) in the U.S. in April 2008, and the HeartMate XVE is the only device approved by the FDA for both destination therapy and BTT, Thoratec said. A continuous flow device, the HeartMate II is an implantable LVAD powered by a rotary pumping mechanism and is designed to have a much longer functional life than pulsatile devices and to operate more simply and quietly. The device provides blood flow through the circulatory system on a continuous basis with only one moving part. It is also smaller and easier to implant than a pulsatile device, according to the company.

• Aterovax (Paris), a company developing products for atherosclerosis, reported data demonstrating that its blood test for secretory phospholipase A2 (sPLA2) activity significantly improves cardiovascular risk prediction in patients with stable coronary artery disease (CAD) over a five year period, independent of established risk markers, including C-reactive protein. sPLA2 is in a family of pro-inflammatory enzymes linked to the formation and destabilization of atherosclerotic plaques. Aterovax's sPLA2 activity test was used in 3,778 patients in the PEACE (Prevention of Events with Angiotensin Converting Enzyme Inhibition) trial.

The PEACE trial is a randomized, multi-center study of trandolapril vs. placebo in 8,290 patients with stable CAD. sPLA2 activity levels identified individuals at increased risk of cardiovascular death (CVD) and the combination of CVD, myocardial infarction (MI) or stroke during five years of follow-up.

After adjusting for baseline differences, individuals with the highest levels of sPLA2 activity had a 78% higher risk of CVD and a 56% higher risk of CVD, MI or stroke than patients with the lowest levels of sPLA2 activity. In addition, sPLA2 activity was a stronger marker for risk prediction than other established biomarkers, including C-reactive protein and lipoprotein-associated phospholipase A2.

• PgxHealth (Newton, Massachusetts) reported the launch of its genetic test for familial Dilated Cardiomyopathy (DCM), an inherited heart disease which is the leading cause of heart transplants and a possible cause of sudden cardiac death. According to the company, the introduction of the Familion DCM test marks the third significant genetic test it has launched over the past 18 months. The test expands the Familion family of genetic tests to six index tests used to diagnose or confirm familial heart disease, PgxHealth noted.

According to the company, this new test is a complex genetic test that sequences the twelve genes most commonly associated with DCM. In addition, it is the only DCM panel to include SCN5A and ANKRD1, two genes known to account for 5% of gene mutations in familial DCM patients, PgxHealth said.