Medical Device Dailys

MUNICH, Germany — A new-generation drug-eluting stent, the BioMatrix III from Biosensors Europe (Morges Switzerland) using a bioabsorbable polymer compares well at nine months to a first generation equivalent, but longer terms results are needed before the safety and efficacy of the new product will be known.

Results of the LEADERS study (Limus Eluted from a Durable versus Erodable Stent Coating) presented at the European Society of Cardiology's (ESC) annual congress showed that BioMatrix III met the study's primary endpoint to prove it is not inferior to the venerable Cypher stent from Cordis (Warren, New Jersey), which has a durable polymer coating carrying the anti-restenosis therapeutic sirolimus.

The endpoint was the rate of major adverse cardiac events defined as cardiac death, myocardial infarction and justified targeted valve revascularization at nine months.

Coated with a a sirolimus equivalent called biolimus, the BioMatrix stent platform is covered with a polylactic acid polymer that dissolves into carbon dioxide and water during a period of 6-9 months.

The study looked at 850 patients randomized into two groups to receive the different stents and is promoted as an all-comers trial as patient criteria did not exclude those with ST elevation myocardial infarction (STEMI), chronic total occlusion (CTO) and bifurcations.

Laura Mauri from the Harvard Clinical Research Institute (Cambridge, Massachusetts) was invited to comment on the report at the ESC congress and offered a guarded endorsement of the trial.

While congratulating LEADERS as one of the first industry sponsored all-comers trials, and saying the consistency of results across patient subgroups was reassuring, Mauri noted, "There is not sufficient power to determine the safety or efficacy in each of these subgroups."

While a fully biodegradable polymer might have a unique advantage over a durable polymer the durability of the clinical results is unknown for a polymer that dissolves at nine months and therefore "the hypothesis that the new biolimus-eluting stent has improved late safety and preserved efficacy compared to sirolimus-eluting stent remains to be proven in further follow-up."

One-year data from the LEADERS trial, sponsored by BioSensors, will be presented at the October Transcatheter Cardiovascular Therapeutics conference in Washington.

Also at the ESC meeting, data presented by Italian researchers shows that Medtronic (Minneapolis) cardiac devices equipped with OptiVol Fluid Status Monitoring Alerts may give physicians advance warning of their heart failure patients' worsening condition, thus reducing the rate of heart failure hospitalizations and clinically relevant events.

Two-year follow-up data, presented by Maurizio Landolina, MD, shows this may be as much as a 50% reduction.

"Heart failure is a progressive condition, frequently marked by worsening symptoms such as fluid build-up in the chest cavity, which often must be addressed in hospital," said Landolina, of Fondazione Policlinico S. Matteo IRCCS (Pavia, Italy). "Our research team concluded that devices with OptiVol may detect this decompensation in a broad population of heart failure patients. By allowing the chance for timely discovery and prompt intervention, the alerts could lead to a reduced number of events such as heart failure hospitalizations."

Involving 532 patients at 34 Italian centers, the purpose of the study was to describe the use of intrathoracic impedance monitoring in clinical practice, and evaluate the clinical usefulness of the associated alert in reducing clinically relevant events and heart failure hospitalizations.

OptiVol Fluid Status Monitoring is found only on Medtronic cardiac resynchronisation therapy-defibrillators (CRT-Ds) and implantable cardioverter-defibrillators (ICDs). It uses low electrical pulses that travel across the thoracic cavity (the chest area encompassing the lungs and heart) to measure the level of resistance, indicating fluid in the chest a common symptom of heart failure. Since normal fluid levels vary from patient to patient, and fluid accumulation can be either slow or rapid, OptiVol's ability to measure fluid status trends over time can provide important insights that are used in conjunction with ongoing monitoring of other patient symptoms.

Remote management of cardiac device patients with OptiVol who are on the Medtronic CareLink Network is further enhanced with the company's wireless device offerings, including the Concerto CRT-D, Virtuoso ICDs and Vision 3-D devices. Physicians in Europe can pre-program these devices' CareAlerts signals, which are designed to give automatic notification to the physician via text message, e-mail or a Medtronic CareLink web site message when a patient's individualized OptiVol threshold is crossed, without the physician having to see the patient in-office for diagnosis.

OptiVol Alerts are for investigational use only in the U.S.