Christine Houde

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.

Atherosclerotic Burden Findings in Young Cryptogenic Stroke Patients With and Without a Patent Foramen Ovale

Background and Purpose— To further determine the mechanisms of cryptogenic stroke or transient ischemic attack in young patients, we evaluated indices of atherosclerosis in patients ≤55 years old diagnosed with cryptogenic cerebrovascular event comparing those with patent foramen ovale (PFO) with those without PFO. Methods— This was a prospective study including 100 consecutive patients ≤55 years old (mean age, 45±8 years; 56 males) diagnosed with cryptogenic stroke/transient ischemic attack. PFO was identified in 59 of these patients with the use of transesophageal echocardiography with contrast study. The following surrogate markers of atherosclerosis were evaluated in all patients: carotid intima media thickness as measured by carotid ultrasonography and endothelial function as determined by brachial flow-mediated vasodilation. The same measurements were obtained in a control group of 50 age- and sex-matched control subjects. Results— Patients without PFO were more likely to be current smokers and obese and more frequently had a history of hypertension and dyslipidemia. Carotid intima media thickness measurements were higher (P<0.0001) in patients without PFO (1.03±0.31 mm) compared with those with PFO (0.75±0.20 mm) and control subjects (0.79±0.17 mm). The absence of PFO was also associated with lower brachial flow-mediated vasodilation (without PFO: 5.04±3.39%; with PFO: 7.16±4.09%; control subjects: 7.33±4.07%; P=0.02). There were no differences in carotid intima media thickness and flow-mediated vasodilation between patients with stroke/transient ischemic attack with PFO and control subjects. The presence of PFO was independently associated with reduced carotid intima media thickness (P<0.0001) and increased flow-mediated vasodilation (P=0.019). Conclusions— In patients ≤55 years old diagnosed with cryptogenic stroke/transient ischemic attack, the presence of PFO was associated with a lower atherosclerotic burden as measured by carotid intima media thickness and endothelial function with no differences compared with a control group without cerebrovascular event. These results suggest that an atherosclerotic-mediated mechanism may be involved in cryptogenic stroke/transient ischemic attack in patients without PFO, whereas a nonatherosclerotic mechanism may mediate the cerebrovascular event in the presence of PFO.

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.

Prosthetic Valve Endocarditis After Transcatheter Valve Replacement: A Systematic Review

OBJECTIVES The aim of this review is to describe the incidence, features, predisposing factors, and outcomes of prosthetic valve endocarditis (PVE) after transcatheter valve replacement (TVR). BACKGROUND Very few data exist on PVE after TVR. METHODS Studies published between 2000 and 2013 regarding PVE in patients with transcatheter aortic valve replacement (TAVR) or transcatheter pulmonary valve replacement (TPVR) were identified through a systematic electronic search. RESULTS A total of 28 publications describing 60 patients (32 TAVRs, 28 TPVRs) were identified. Most TAVR patients (66% male, 80 ± 7 years of age) had a very high-risk profile (mean logistic EuroSCORE: 30.4 ± 14.0%). In TPVR patients (90% male, 19 ± 6 years of age), PVE was more frequent in the stenotic conduit/valve (61%). The median time between TVR and infective endocarditis was 5 months (interquartile range: 2 to 9 months). Typical microorganisms were mostly found with a higher incidence of enterococci after TAVR (34.4%), and Staphylococcus aureus after TPVR (29.4%). As many as 60% of the TAVR-PVE patients were managed medically despite related complications such as local extension, embolism, and heart failure in more than 50% of patients. The valve explantation rate was 57% and 23% in balloon- and self-expandable valves, respectively. In-hospital mortality for TAVR-PVE was 34.4%. Most TPVR-PVE patients (75%) were managed surgically, and in-hospital mortality was 7.1%. CONCLUSIONS Most cases of PVE post-TVR involved male patients, with a very high-risk profile (TAVR) or underlying stenotic conduit/valve (TPVR). Typical, but different, microorganisms of PVE were involved in one-half of the TAVR and TPVR cases. Most TPVR-PVE patients were managed surgically as opposed to TAVR patients, and the mortality rate was high, especially in the TAVR cohort.

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.

Lobectomy in the treatment of the scimitar syndrome.

The scimitar syndrome is a congenital anomaly that consists mainly of total or partial anomalous venous drainage of the right lung to the inferior vena cava. We report the case of an 8-year-old girl diagnosed at birth as having a scimitar syndrome and who presented with recurrent right lower lung infections. She underwent resection of the lower half of her right lung without diversion of the anomalous venous drainage of the upper portion of the lung. She improved rapidly postoperatively and the shunt fraction diminished.

Effect of Clopidogrel and Aspirin vs Aspirin Alone on Migraine Headaches After Transcatheter Atrial Septal Defect Closure: The CANOA Randomized Clinical Trial

IMPORTANCE The occurrence of new-onset migraine attacks is a complication of transcatheter atrial septal defect (ASD) closure. It has been suggested that clopidogrel may reduce migraine attacks after ASD closure. OBJECTIVE To assess the efficacy of clopidogrel, used in addition to taking aspirin, for the prevention of migraine attacks following ASD closure. DESIGN, SETTING, AND PARTICIPANTS Randomized, double-blind clinical trial performed in 6 university hospitals in Canada. Participants were 171 patients with an indication for ASD closure and no history of migraine. INTERVENTIONS Patients were randomized (1:1) to receive dual antiplatelet therapy (aspirin + clopidogrel [the clopidogrel group], n = 84) vs single antiplatelet therapy (aspirin + placebo [the placebo group], n = 87) for 3 months following transcatheter ASD closure. The first patient was enrolled in December 2008, and the last follow-up was completed in February 2015. MAIN OUTCOMES AND MEASURES The primary efficacy outcome was the monthly number of migraine days within the 3 months following ASD closure in the entire study population. The incidence and severity of new-onset migraine attacks, as evaluated by the Migraine Disability Assessment questionnaire, were prespecified secondary end points. A zero-inflated Poisson regression model was used for data analysis. RESULTS The mean (SD) age of the participants was 49 (15) years and 62% (106) were women. Patients in the clopidogrel group had a reduced mean (SD) number of monthly migraine days within the 3 months following the procedure (0.4 [95% CI, 0.07 to 0.69] days) vs the placebo group (1.4 [95% CI, 0.54 to 2.26] days; difference, -1.02 days [95% CI, -1.94 to -0.10 days]; incident risk ratio [IRR], 0.61 [95% CI, 0.41 to 0.91]; P = .04) and a lower incidence of migraine attacks following ASD closure (9.5% for the clopidogrel group vs 21.8% for the placebo group; difference, -12.3% [95% CI, -23% to -1.6%]; odds ratio [OR], 0.38 [95% CI, 0.15 to 0.89]; P = .03). Among patients with migraines, those in the clopidogrel group had less-severe migraine attacks (zero patients with moderately or severely disabling migraine attacks vs 37% [7 patients] in the placebo group; difference, -36.8% [95% CI, -58.5% to -15.2%]; P = .046). There were no between-group differences in the rate of patients with at least 1 adverse event (16.7% [14 patients] in the clopidogrel group vs 21.8% [19 patients] in the placebo group; difference, -5.2% [95% CI, -17% to 6.6%]; P = .44). CONCLUSIONS AND RELEVANCE Among patients who underwent transcatheter ASD closure, the use of clopidogrel and aspirin, compared with aspirin alone, resulted in a lower monthly frequency of migraine attacks over 3 months. Further studies are needed to assess generalizability and durability of this effect. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00799045.

Delayed Improvement in Valve Hemodynamic Performance After Percutaneous Pulmonary Valve Implantation

We report the case of a 21-year-old woman with a severely stenotic pulmonary homograft who underwent percutaneous pulmonary valve implantation, with no significant change in transvalvular gradient within the 24 hours after the procedure. Major improvement in hemodynamic valve performance of more than 60% decrease in transvalvular gradient and more than 30% increase in pulmonary valve area was observed 3 months after the procedure, showing that hemodynamic improvement can occur late after pulmonary valve implantation. An echocardiogram after 3 months should be done before concluding the procedure failed and that reintervention is necessary.

Relationship between interatrial communication, ductus arteriosus, and pulmonary flow patterns in fetuses with transposition of the great arteries: prediction of neonatal desaturation

BACKGROUND The relationship between interatrial communication, ductus arteriosus, and pulmonary flow in transposition of the great arteries and intact ventricular septum may help predict postnatal desaturation. METHODS Echocardiographic data of 45 fetuses with transposition of the great arteries and intact ventricular septum and 50 age-matched controls were retrospectively reviewed. Interatrial communication, left and right ventricular output, flow in the ductus arteriosus, as well as effective pulmonary flow were measured. Patients were divided into two groups on the basis of postnatal saturations: group 1 had saturations ⩽50% and group 2 >50%. RESULTS Of 45 fetuses, 13 (26.7%) were classified into group 1. Compared with fetuses in group 2, they had a smaller interatrial communication (2.9 versus 4.0 mm, p=0.004) and more retrograde diastolic flow in the ductus arteriosus (92 versus 23%, p=0.002). Both groups showed a significant decrease in ductal flow compared with controls. Patients in group 2 had a higher effective pulmonary flow compared with controls. There was a mild correlation between left ventricular output and size of the interatrial communication (Spearmans rank correlation 0.44). CONCLUSION A retrograde diastolic flow is present in most of the fetuses with postnatal desaturation. Fetuses with transposition of the great arteries have a lower flow through the ductus arteriosus compared with controls. Fetuses without restrictive foramen ovale have higher effective pulmonary flow. Peripheral pulmonary vasodilatation due to higher oxygen saturation in pulmonary arteries in the case of transposition of the great arteries could be one possible cause.