A Medical Device Daily

Pulmonary vein antrum isolation (PVI), a new treatment for atrial fibrillation (AF), causes irregular heartbeats to regress in most patients and improves heart failure patients’ quality of life, according to a Cleveland Clinic (Cleveland) study. Results of the study were presented at the American Heart Association ’s (AHA; Dallas) scientific sessions in Chicago this week.

PABA CHF (Pulmonary Vein Antrum Isolation vs. AV Node Ablation with Bi-Ventricular Pacing for Treatment of Atrial Fibrillation in Patients with Congestive Heart Failure) is the first randomized, controlled study to compare two current approaches to treating AF in patients with congestive heart failure. AF is a condition characterized by irregular heartbeats.

PVI is designed to cure AF by electrically isolating all four pulmonary veins from the left atrium. During the procedure, also known as pulmonary vein ablation (PVAI), doctors insert catheters into the blood vessels of the atrium. Radio frequency energy is then used to block the pathway of irregular heartbeats.

During AV node ablation with biventricular pacing (AVNA/BiV), a catheter is used to deliver an electrical current to the part of the heart causing the AF to prevent the irregular heartbeats. The patient relies on the use of an implantable cardioverter defibrillator (ICD) to shock the heart into normal rhythm when AF arises.

“The study results suggest that PVI is superior to AVNA/BiV in terms of both freedom from atrial fibrillation and improving patients’ quality of life,” said Andrea Natale, MD, section head of Electrophysiology and Pacing at the Cleveland Clinic. “Given many patients are afflicted by both congestive heart failure and atrial fibrillation, PVI is a real treatment option.”

Recent studies had shown that patients who are pacemaker-dependent may benefit more from a biventricular device than a standard dual chamber device.

“The question then becomes, is it better to cure the atrial fibrillation with pulmonary vein ablation or make patients pacer-dependent,” Natale said. “More research needs to be done to answer this very important question.”

The disorder currently affects 2.3 million Americans and is projected to affect up to 5.6 million Americans by 2050. Individuals with congestive heart failure are at an increased risk for developing atrial fibrillation.

In other AHA news:

• Preliminary three-year clinical data suggest the Cypher sirolimus-eluting coronary stent may be a less invasive long-term alternative to coronary artery bypass grafting (CABG) in patients with multi-vessel coronary artery disease. These results were presented by principal investigator Patrick Serruys, MD, PhD, of the Thoraxcenter, Erasmus Medical Center (Rotterdam, the Netherlands), during an award acceptance speech at the Council on Clinical Cardiology Dinner.

“For years, physicians have debated the merits of stent procedures vs. coronary artery bypass grafting in challenging patients with lesions in two or more vessels,” Serruys said. “These preliminary three-year data suggest that percutaneous procedures using the Cypher stent may be a viable alternative to surgery in these patients and much less invasive.”

The Arterial Revascularization Therapy Study II (ARTS II Study), sponsored by Cordis (Miami Lakes, Florida) is an extension of the ARTS I Study, conducted in 1997, which compared results of bare metal stents (BMS) to those obtained with CABG.

At three-year follow-up, the MACCE rates (a composite for death, stroke and heart attack, as well as any re-vascularization) of the Cypher stent arm vs. the CABG arm were similar. Specifically, 80.2% of the patients who received the Cypher stent remained free of MACCE, compared to 83.9% of the patients in the CABG arm.

In addition, the Cypher stent fared significantly better than the BMS arm in the same clinical endpoint, as 65.3% of the patients who received a bare-metal stent did not experience a MACCE event after three years.

In addition, the severe event rate (a composite for death, stroke and heart attack) in the Cypher stent arm was lower compared with both the CABG and bare-metal stent arms. Three years after treatment, 91.6% of the patients who received the Cypher stent were alive and did not experience a stroke or a heart attack, compared to 89% of the patients in the CABG arm and 86.7% of the patients in the bare-metal stent arm. The difference between the Cypher stent arm vs. the BMS arm reached statistical significance (p = 0.0065).

ARTS II includes 607 patients from 45 European centers treated with the Cypher. Investigators compared the findings for these patients to those from the ARTS I Trial, which included 602 patients treated with coronary bypass grafting and 600 treated with a BMS.

The CYPHER has not been indicated for patients with multi-vessel disease in the U.S.

• GE Healthcare (Waukesha, Wisconsin) reported the release of a program that allows GE Electrocardiogram (ECG) data to support the FDA HL-7 XML Annotated ECG standard.

The FDA is collecting ECG data in FDA HL-7 XML from clinical trials to assess cardiac safety, particularly the risk of a potentially fatal arrhythmia called Torsades-de-Pointe.

GE’s new program allows Drug Application Sponsors and contract research organizations (CROs) to transform data acquired on GE Healthcare ECG recording and analysis equipment to FDA XML format. The FDA XML format data can then be submitted directly to the FDA for review, thus eliminating the need to comply with the expensive process of certification common of existing solutions.

GE produces MUSE Cardiology Information System and ECG recording and analysis equipment that is used by drug companies, ECG core labs and CROs worldwide for clinical trials and research.