Aims Out-of-hospital cardiac arrest (OHCA) without return of spontaneous circulation (ROSC) despite conventional resuscitation is common and has poor outcomes. Adding extracorporeal membrane oxygenation (ECMO) to cardiopulmonary resuscitation (extracorporeal-CPR) is increasingly used in an attempt to improve outcomes. Methods and results We analysed a prospective registry of 13 191 OHCAs in the Paris region from May 2011 to January 2018. We compared survival at hospital discharge with and without extracorporeal-CPR and identified factors associated with survival in patients given extracorporeal-CPR. Survival was 8% in 525 patients given extracorporeal-CPR and 9% in 12 666 patients given conventional-CPR (P = 0.91). By adjusted multivariate analysis, extracorporeal-CPR was not associated with hospital survival [odds ratio (OR), 1.3; 95% confidence interval (95% CI), 0.8–2.1; P = 0.24]. By conditional logistic regression with matching on a propensity score (including age, sex, occurrence at home, bystander CPR, initial rhythm, collapse-to-CPR time, duration of resuscitation, and ROSC), similar results were found (OR, 0.8; 95% CI, 0.5–1.3; P = 0.41). In the extracorporeal-CPR group, factors associated with hospital survival were initial shockable rhythm (OR, 3.9; 95% CI, 1.5–10.3; P = 0.005), transient ROSC before ECMO (OR, 2.3; 95% CI, 1.1–4.7; P = 0.03), and prehospital ECMO implantation (OR, 2.9; 95% CI, 1.5–5.9; P = 0.002). Conclusions In a population-based registry, 4% of OHCAs were treated with extracorporeal-CPR, which was not associated with increased hospital survival. Early ECMO implantation may improve outcomes. The initial rhythm and ROSC may help select patients for extracorporeal-CPR.

Periodontal Ehlers–Danlos syndrome (pEDS) is a rare condition caused by pathogenic variants in the C1R and C1S genes, encoding subunits C1r and C1s of the first component of the classical complement pathway. It is characterized by early‐onset periodontitis with premature tooth loss, pretibial hyperpigmentation and skin fragility. Rare arterial complications have been reported, but venous insufficiency is rarely described. Here we report 13 novel patients carrying heterozygous pathogenic variants in C1R and C1S including three novel C1S variants (c.962G > C, c.961 T > G and c.961 T > A). In addition to the pEDS phenotype, three patients and one relative displayed widespread venous insufficiency leading to persistent varicose leg ulcers. One patient suffered an intracranial aneurysm with familial vascular complications including thoracic and abdominal aortic aneurysm and dissection and intracranial aneurysm rupture. This work confirms that vascular complications can occur, although they are not frequent, which leads us to propose to carry out a first complete non‐invasive vascular evaluation at the time of the diagnosis in pEDS patients. However, larger case series are needed to improve our understanding of the link between complement pathway activation and connective tissue alterations observed in these patients, and to better assess the frequency, type and consequences of the vascular complications.