SWEDMAF - SWEDMAF

Description:

The goal of the trial was to evaluate mitral valve surgery with pulmonary vein isolation (PVI) using epicardial cryoablation compared with mitral valve surgery alone among patients with permanent atrial fibrillation (AF) and mitral valve disease.

Study Design

Study Design:

Patients Enrolled: 65
Mean Follow Up: 12 months
Mean Patient Age: Mean age 68 years
Female: 22
Mean Ejection Fraction: Baseline EF 56%

Patient Populations:

ECG documented permanent AF for at least 3 months, clinical indication for mitral valve surgery, and age 18-80 years

Exclusions:

Heart failure in New York Heart Association class IV, prior cardiac surgery (except CABG), other combined surgery planned (except CABG), increased surgical risk for prolonged procedure, or complete AV block

Primary Endpoints:

Sinus rhythm at 6 months

Secondary Endpoints:

Sinus rhythm at 12 months; quality of life at 6 and 12 months

Drug/Procedures Used:

Patients were randomized to mitral valve surgery alone (n = 35) or mitral valve surgery with PVI using cryoablation (n = 30). Surgeons were unblinded to treatment assignment but both the patient and the cardiologists remained blinded.

Principal Findings:

Intraoperative ECC time was longer in the mitral valve surgery with cryoablation group than the surgery alone group (146 minutes vs. 119 minutes, p = 0.0015), driven by the 21-minute cryoablation procedure time. Beta-blockers were used in 43% of the surgery plus cryoablation group and 51% of the surgery alone group at 12 months (p = NS).

The primary endpoint of sinus rhythm at 6 months occurred more frequently in the mitral valve surgery with the cryoablation group compared with the mitral valve surgery alone group (73% vs. 46%, p = 0.024), a finding maintained at 12 months (73% vs. 49%, p = 0.042). Adverse events were relatively infrequent, with no deaths in the surgery alone group and two deaths in the surgery with cryoablation group, one of which was due to cancer and one due to heart failure. Bleeding requiring re-operation occurred in one patient in the surgery alone group and three patients in the cryoablation group.

Interpretation:

Among patients with permanent AF and mitral valve disease, mitral valve surgery with pulmonary vein isolation using cryoablation was associated with higher rates of sinus rhythm at 6 months compared with mitral valve surgery without cryoablation.

Surgery with cryoablation restored sinus rhythm and maintained sinus rhythm more so than surgery alone, with few adverse events. While the present study demonstrated benefit of cryoablation with mitral valve surgery, data from the present trial do not provide information of the effect of cryoablation with coronary artery bypass graft surgery (CABG). The long-term benefit of cryoablation during cardiac surgery for AF suppression remains to be evaluated.

References:

Presented by Carina Blomstrom-Lundqvist, MD, at the Heart Rhythm Society Annual Scientific Sessions, Boston, MA, May 2006.

Clinical Topics: Arrhythmias and Clinical EP, Cardiac Surgery, Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Valvular Heart Disease, Cardiac Surgery and Arrhythmias, Cardiac Surgery and Heart Failure, Cardiac Surgery and VHD, Acute Heart Failure, Interventions and Structural Heart Disease

Keywords: Pulmonary Veins, Heart Failure, Heart Valve Diseases, Cryosurgery, Electrocardiography, Coronary Artery Bypass, Mitral Valve


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