March 23, 2005
By Ashley
Starkweather, B.S. and Asher Kimchi M.D.
Milan, Italy – A
recent study shows that patients who suffer from atrial
fibrillation and have prosthetic mitral valve replacements can
undergo transcatheter ablation with positive results. The
study, published by Christopher C. Lang, MB, CHB, et. al.,
from San Raffaele University Hospital in Milan, Italy, in the
March 15, 2005 issue of the Journal of the American College of
Cardiology, looked at twenty-six patients with mitral valve
prostheses (MVP) who underwent circumferential pulmonary vein
ablation for atrial fibrillation (AF) and compared their
outcomes to a control group of fifty-two patients who
underwent ablation for AF and did not have prosthetic mitral
valves. The study concluded that this procedure is both
feasible in this population of patients.
Patients with
prosthetic mitral valves represent an important subgroup of AF
patients for whom appropriate nonpharmacologic therapy has yet
to be established. A possible risk in this group could be
prosthetic valvular damage when performing transcatheter
ablation procedures. This study sought to determine the risks
and benefits for these patients when performing
circumferential pulmonary vein ablation (CPVA) for the
treatment of AF.
Between July
2001 and July 2003, twenty-six patients with mechanical mitral
valves were identified and enrolled in the study and underwent
CPVA. For each of these patients, two control subjects were
matched based on left atrial diameter, chronic or paroxysmal
AF, duration of symptoms, age, gender, history of
hypertension, and impaired left ventricular function. All MVP
patients and controls were resistant to at least two
anti-arrhythmic drugs. Follow-up was performed for twelve
months and Holter recordings were performed for all patients
at 3, 6, and 12 months.
There were no
significant differences between the groups in regards to age,
duration of AF, LA diameter, gender, LV hypertrophy or LV
impairment. There was a trend towards longer procedure time in
the MVP group, however, this trend was not significant.
Fluoroscopy times were significantly increased in this group
(35.3 +/- 21min versus 20.9 +/- 15 min in controls), which
signifies an increased exposure to radiation.
At the end of
follow-up, 73 percent of MVP patients were in sinus rhythm,
compared to 75 percent in the controls. Atrial tachycardia
occurred in six (23 percent) of MVP patients, requiring repeat
ablation in three, and one control patient (2 percent) which
resolved without intervention. Some complications did occur in
the MVP groups, including one transient ischemic attack and
one femoral pseudoaneurysm. No complications occurred in the
control group.
The results of
this study suggest that CPVA is feasible in AF patients with
MVP, with similar risks and outcomes to those of AF patients
without MVP. Complication rates were higher, however, in MVP
patients as well as radiation exposure and post-ablation
atrial tachycardia.
Co-authors:
Vincenzo Santinelli MD, Giuseppe Augello MD, Amedeo Ferro MD,
Filippo Gugliotta BEng, Simone Gulletta MD, Gabriele
Vicedomini MD, Cézar Mesas MD, Gabriele Paglino MD, Simone
Sala MD, Nicoleta Sora MD, Patrizio Mazzone MD, Francesco
Manguso MD, PhD and Carlo Pappone MD, PhD
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