Objective We aimed to describe the clinical outcomes of patients receiving veno-arterial extracorporeal membrane oxygenation therapy considering clinical context and pH at cannulation. Methods We reviewed all patients having received veno-arterial extracorporeal membrane oxygenation therapy at a tertiary referral center during the 2005-2020 period with 1-year complete follow up. Our cohort was divided in three groups according to the pH level at cannulation: pH<7 (group 1), pH 7-7.2 (group 2) and pH>7.2 (group 3). Survival was analyzed using Kaplan–Meier method. Association between pH group and survival was estimated using a Cox model. Results Among the 951 patients in our database, 572 were included in 3 different groups according to their pH at implantation: 60 patients in group 1, 115 in group 2 and 397 in group 3. Main indications of mechanical support were refractory cardiogenic shock (36%), post cardiotomy (28%), early graft failure (12%), refractory cardiac arrest (11%). One-year survival rate was 13% in group 1, 36% in group 2, 43% in group 3 respectively (p<0.001). Death mainly occurred within the first month. The strong correlation between pH and lactates led to propose a simple “three seven rule”: pH<7 and lactate >7 was associated with <7% survival. Conclusion Extracorporeal veno-arterial membrane oxygenation should be considered with caution in patients with pH<7. Lactates and pH level might be important parameters to elaborate a new score to predict survival in this population. The simplicity of the “three seven rule” can be very relevant when facing emergency situations.

Dear Editor, First we would like to thank Dr Lopez de la Cruz for her comments and interest about our recently published article “the odyssey of suturing cardiac wounds: lessons from the past”. We highly appreciated and agree with the complements she made especially about Larrey and Milton role in this field. One should also note Theodore Tuffier’s attempt at cardiac resuscitation in 1898 in a young man dying on the wards at La Pitié Hospital (Paris)¹. Although this act was performed on an unwounded heart it adds information about the history of surgical approach in such dramatic condition. We do recognize left anterolateral thoracotomy as the gold standard in an emergency room to treat a penetrating cardiac injury. However a median longitudinal sternotomy may be discussed in our opinion if the patient arrived directly in a cardiac surgery operating theater. The patent presented in our paper was directly brought in our operative theater of cardiac surgery and managed immediately by cardiac surgeons and cardiac anesthesiologists, with a cardiopulmonary bypass ready, dedicated scrub nurses and perfusionist. In such specific conditions a sternotomy may be discussed, depending on the context and the anatomical suspected lesions (it was the option retained in the presented case and the surgical procedure was safely performed with good outcome). Clearly, in a peripheral hospital or at the emergency room sternotomy is not an option to be considered and we agree with Dr Lopez de la Cruz.

Cardiac wounds have been described for centuries and still remain often fatal. For a long period of time suture of a myocardial laceration was thought to be absolutely impossible if not sacrilege. It is only at the end of the 19th century that pioneers decided to defy such dogma in desperate cases. Nowadays it seems obvious that a cardiac stab wound require emergent surgery whenever possible. The story of cardiac wounds highlights nicely the change of mind that is required to accept progress and new procedures in medicine.