Patent foramen ovale closure in children without cardiopathy: Child-PFO study.

BACKGROUND: Closure of patent foramen ovale is well-managed in adults, but is performed less frequently in children. AIM: To analyse all patent foramen ovale closures performed in the past 20 years in French paediatric centres. METHODS: Retrospective study of patent foramen ovale closures in children without cardiopathy in nine centres between 2000 and 2019. RESULTS: Forty-one procedures were carried out in children (median age: 14.9 years). Thirty-one patent foramen ovales were closed after a transient ischaemic attack or stroke, six for a left-to-right shunt and four for other reasons. Transthoracic echocardiography was used for 72.2% of the diagnoses and transoesophageal echocardiography for 27.8%. A substantial degree of shunting was found in 42.9% of patients and an atrial septal aneurysm in 56.2%. General anaesthesia with transoesophageal echocardiography guidance was performed in 68.3% of the procedures; local anaesthesia and transthoracic echocardiography or intracardiac echocardiography was performed in 31.7%. The success rate was 100%. The median fluoroscopy time was 4.14minutes: 3.55minutes with transoesophageal echocardiography; and 4.38minutes with transthoracic echocardiography (P=0.67). There was only one periprocedural complication (2.4%). Postoperatively, 80,5% of patients were treated with aspirin and 12,2% with an anticoagulant. The rate of complete occlusion was 56.8% immediately after the procedure, 68.6% at 1 year and 92.3% at the last follow-up. There were no delayed complications or cases of recurrent stroke during follow-up (median follow-up: 568 days). CONCLUSION: Closure of patent foramen ovale in children appears to be safe and effective, as we noted a low rate of immediate complications, no delayed complications and no stroke recurrence in this indication.

Endogenous angiotensin II in the regulation of hypoxic pulmonary vasoconstriction in anaesthetized dogs.

INTRODUCTION: The role played by several vasoactive mediators that are synthesized and released by the pulmonary vascular endothelium in the regulation of hypoxic pulmonary vasoconstriction (HPV) remains unclear. As a potent vasoconstrictor, angiotensin II could be involved. We tested the hypothesis that angiotensin-converting enzyme inhibition by enalaprilat and type 1 angiotensin II receptor blockade by candesartan would inhibit HPV. METHODS: HPV was evaluated in anaesthetized dogs, with an intact pulmonary circulation, by examining the increase in the Ppa-Ppao gradient (mean pulmonary artery pressure minus occluded pulmonary artery pressure) that occurred in response to hypoxia (inspiratory oxygen fraction of 0.1) at constant pulmonary blood flow. Plasma renin activity and angiotensin II immunoreactivity were measured to determine whether activation or inhibition of the renin-angiotensin system was present. RESULTS: Administration of enalaprilat and candesartan did not affect the Ppa-Ppao gradient at baseline or during hypoxia. Plasma renin activity and angiotensin II immunoreactivity increased during hypoxia, and subsequent measurements were consistent with effective angiotensin-converting enzyme inhibition after administration of enalaprilat, and with angiotensin receptor blockade after administration of candesartan. CONCLUSION: These results suggest that, although the renin-angiotensin system was activated in hypoxia, angiotensin II is not normally involved in mediating acute HPV.