Urinary FOXP3 messenger RNA and renal-allograft rejection.

n engl j med 354;21 www.nejm.org may 25, 2006 2289 To the Editor: In their study of circumferential pulmonary-vein ablation in patients with chronic atrial fibrillation, Oral et al. (March 2 issue)1 do not mention evaluation or discuss the potential complication of pulmonary-vein stenosis. In their definition of ostial stenosis, they rely on the electroanatomical “tube depiction” method as a guide; this is a suboptimal method for exact ostial demarcation since the tubes are automatically centralized around the acquired points. Any movement by the patient can also make electroanatomical mapping even more inaccurate. Although the authors report no follow-up for the assessment of pulmonary-vein stenosis, a recent study involving magnetic resonance imaging detected a variable degree of stenosis in 38 percent of pulmonary veins ablated with the use of the electroanatomical approach.2 A recent worldwide survey has shown that pulmonary-vein stenosis occurs in about 1.3 percent of patients.3 In addition, the authors mention that a patient died of pneumonia after ablation. However, they give no details about any further diagnostic investigation. Many reports, including one by Salamon et al.4 in the same issue of the Journal, have emphasized that pulmonary-vein stenosis is associated with symptoms that may mimic common lung diseases, which can lead to unnecessary diagnostic and therapeutic procedures.5