Jean-Marc Côté

Catheter ablation for cardiac arrhythmias: A 14-year experience with 5330 consecutive patients at the Quebec Heart Institute, Laval Hospital

BACKGROUND Catheter ablation is a curative treatment with excellent success and minimal complication rates for patients with supraventricular or ventricular arrhythmias. METHODS The acute outcomes and complications of all catheter ablation procedures for supraventricular and ventricular arrhythmias performed at the Quebec Heart Institute (Sainte-Foy, Quebec) during a 14-year period from January 1, 1993, to December 31, 2006, were prospectively assessed. The ablation procedures were classified according to the arrhythmias induced using standard electrophysiological techniques and definitions. Immediate success and complication rates were prospectively included in the database. RESULTS A total of 5330 patients had catheter ablation performed at the Institute during the period assessed. The mean (+/- SD) age of patients was 50 +/- 18 years (range four to 97 years), and 2340 patients (44%) were men. Most of the patients were younger than 75 years (group 1), and 487 (9%) were 75 years of age and older (group 2). Indications for ablations were as follows: atrioventricular nodal re-entry tachycardia (AVNRT) in 2263 patients, accessory pathways in 1147 patients, atrioventricular node ablation in 803 patients, typical atrial flutter in 377 patients and atrial tachycardia in 160 patients; 580 patients had other ablation procedures. The overall success rates were 81% for atrial tachycardia, 92% for accessory pathways or flutter, and 99% for AVNRT or atrioventricular node ablation. There was no difference in the success rates of the younger (group 1) and older (group 2) patients. Seventy-seven patients (1.4%) had complications, including 11 major events (myocardial infarction in one patient, pulmonary embolism in three patients and permanent pacemaker in seven patients). In patients undergoing AVNRT ablation, two had a permanent pacemaker implanted immediately after the procedure and three had a permanent pacemaker implanted at follow-up. CONCLUSIONS The results confirm that radiofrequency ablation is safe and effective, supporting ablation therapy as a first-line therapy for the majority of patients with cardiac arrhythmias.

Mutations in SGOL1 cause a novel cohesinopathy affecting heart and gut rhythm

The pacemaking activity of specialized tissues in the heart and gut results in lifelong rhythmic contractions. Here we describe a new syndrome characterized by Chronic Atrial and Intestinal Dysrhythmia, termed CAID syndrome, in 16 French Canadians and 1 Swede. We show that a single shared homozygous founder mutation in SGOL1, a component of the cohesin complex, causes CAID syndrome. Cultured dermal fibroblasts from affected individuals showed accelerated cell cycle progression, a higher rate of senescence and enhanced activation of TGF-β signaling. Karyotypes showed the typical railroad appearance of a centromeric cohesion defect. Tissues derived from affected individuals displayed pathological changes in both the enteric nervous system and smooth muscle. Morpholino-induced knockdown of sgol1 in zebrafish recapitulated the abnormalities seen in humans with CAID syndrome. Our findings identify CAID syndrome as a novel generalized dysrhythmia, suggesting a new role for SGOL1 and the cohesin complex in mediating the integrity of human cardiac and gut rhythm.

Incidence, Timing, and Predictive Factors of New-Onset Migraine Headache Attack After Transcatheter Closure of Atrial Septal Defect or Patent Foramen Ovale

The objectives of this study were to evaluate the incidence, predictive factors, and duration of migraine headache attack (MHA) after transcatheter atrial septal defect (ASD) or patent foramen ovale (PFO) closure. A total of 260 consecutive patients who underwent ASD or PFO closure in our center answered a structured headache questionnaire focused in 3 period times, including (1) at baseline (just before closure), (2) within the 3 months after ASD-PFO closure, and (3) at the last (median 27 months, range 6 to 80 months) follow-up. All questionnaires were evaluated by a neurologist who established the diagnosis of MHA with or without aura, according to International Headache Society criteria. The Amplatzer ASD or PFO device was used in 95% of the patients, and aspirin, for at least 6 months, was the antithrombotic treatment in 91% of the cases. A total of 185 patients (71%) had no history of MHA before ASD-PFO closure, and these constituted the study population (mean age 39 +/- 21 years). MHA occurred in 13 patients (7%) after ASD-PFO closure, with aura in 9 of them. MHA appeared after a median of 10 days (range 0.3 to 30 days) after the procedure and were still present at the last follow-up (23 +/- 17 months) in 9 patients (69%). The median number of MHA within the 3 months after the procedure was 4 per month (interquartile range 1 to 23), and decreased to 1 per month (interquartile range 0.3 to 1) at the latest follow-up (p = 0.03). Compared with the patients who did not develop MHA, patients with MHA after ASD-PFO closure were younger (26 +/- 16 vs 39 +/- 21 years; p = 0.02) and were more likely to have undergone ASD closure (100% vs 58%; p = 0.001). In the multivariate analysis, ASD closure was the only predictor of MHA occurrence after the procedure (odds ratio 7.7; 95% confidence interval 1.5 to 22; p = 0.01). In conclusion, MHA, mostly with aura, occurred in 7% of patients after transcatheter ASD-PFO closure and persisted in most of them after a mean follow-up of 2 years. ASD closure was the only independent predictor of MHA occurrence after the procedure. These results suggest that mechanisms other than device composition are involved in the occurrence of MHA in these cases.

Enhanced Thrombogenesis but Not Platelet Activation Is Associated With Transcatheter Closure of Patent Foramen Ovale in Patients With Cryptogenic Stroke

Background and Purpose— No studies have yet determined whether antiplatelet or anticoagulant therapy is the more appropriate treatment after transcatheter closure of patent foramen ovale (PFO) in patients with cryptogenic stroke. The objective of this study was to prospectively evaluate the presence, degree, and timing of activation of the platelet and coagulation systems after transcatheter closure of PFO in patients with cryptogenic stroke. Methods— Twenty-four consecutive patients (mean age, 44±10 years; 11 men) with previous cryptogenic stroke who had undergone successful transcatheter closure of PFO were included in the study. Prothrombin fragment 1+2 (F1+2) and thrombin–antithrombin III (TAT) were used as markers of coagulation activation, and soluble P-selectin and soluble CD40 ligand were used as markers of platelet activation. Measurements of all hemostatic markers were taken at baseline just before the procedure and at 7, 30, and 90 days after device implantation. Results— F1+2 and TAT levels increased from 0.41±0.16 nmol/L and 2.34±1.81 ng/mL, respectively, at baseline to a maximal value of 0.61±0.16 nmol/L and 4.34±1.83 ng/mL, respectively, at 7 days, gradually returning to baseline levels at 90 days (P<0.001 for both markers). F1+2 and TAT levels at 7 days after PFO closure were higher than those obtained in a group of 25 healthy controls (P<0.001 for both markers). Levels of soluble P-selectin and soluble CD40 ligand did not change at any time after PFO closure. Conclusions— Transcatheter closure of PFO is associated with significant activation of the coagulation system, with no increase in platelet activation markers. These findings raise the question of whether optimal antithrombotic treatment after PFO closure should be short-term anticoagulant rather than antiplatelet therapy.

Life-threatening hemoptysis following the Fontan procedure

Two cases of life-threatening recurrent hemoptysis occurring 10 years after a Fontan operation are presented. Bleeding from aortopulmonary collateral vessels was responsible for this complication in both cases, and the importance of systematic selective angiography of all potential origins of such abnormal vessels, including those arising from the abdominal aorta, is highlighted. Although coil embolization of aortopulmonary collateral vessels is usually definitive, pulmonary lobectomy may be necessary. The present report demonstrates, for the first time, that rescue extracorporeal membrane oxygenation support can be used as a bridge to surgery in case of severe uncontrollable hemoptysis in such cases.