Dottorato in FISIOPATOLOGIA ED IMAGING CARDIO-TORACO-VASCOLARE

Titolo della tesi: Supporto con ECMO veno-arterioso nello shock cardiogenico: gli effetti deleteri sul ventricolo sinistro sono una peculiarità dell’ECMO o dipendono dal sito di cannulazione per l’outflow?

Background The common femoral artery is the preferred cannulation site for veno-arterial extracorporeal membrane oxygenation (femoro-femoral: FF-ECMO. This results in retrograde aortic flow, which increases the left ventricular afterload and can lead to severe pulmonary edema and thrombosis of the cardiac chambers. Right axillary artery cannulation (femoral-axillary: FA-ECMO) provides partial anterograde aortic flow, which may potentially prevent some of these complications. This study aimed to compare the 90-day mortality and complication rates between FA-ECMO and FF-ECMO. Methods All consecutive adult patients affected with cardiogenic shock and who received peripheral VA- ECMO between 2013 and 2019 at our institution were retrospectively included. The exclusion criteria were refractory cardiac arrest, multiple VA-ECMO implantations due to need for vascular access changes, weaning failure, or ICU readmission. The primary endpoint was the 90-day mortality rate. The secondary endpoints were vascular access complications, stroke, and other complications related to retrograde blood flow. A statistical approach using inverse probability of treatment weighting (IPTW) was used to estimate the effect of the cannulation site on the outcomes. Outcomes were estimated using logistic regression analysis. Results During the study period, VA-ECMO was performed on 534 patients. Patients with refractory cardiac arrest (n=77, 14%) and those supported by multiple VA-ECMO (n=92, 17%) were excluded. Out of the 333 included patients (n=209 FA-ECMO; n=124 FF-ECMO), the main indications for VA-ECMO implantation were post-cardiotomy (33%, n=109), dilated cardiomyopathy (20%, n=66), post-cardiac transplantation (15%, n=50), acute myocardial infarction (14%, n=46) or other etiologies (18%, n=62). The median SOFA score was 9 (range 7-11), and the crude 90-day mortality rate was 53% (n=175). After IPTW , the 90-day mortality was similar in the FA- ECMO and FF-ECMO groups (54% vs. 58%, IPTW-OR=0.84[0.54-1.29]). Axillary artery cannulation was associated with significantly fewer local infections (OR=0.21, 95% CI:0.09- 0.51), limb ischemia (OR= 0.37, 95% CI:0.17-0.84), bowel ischemia (OR=0.16, 95% CI:0.05- 0.51) and pulmonary edema (OR=0.52, 95% CI:0.29-0.92) episodes, but with a higher rate of stroke (OR=2.87, 95% CI:1.08-7.62) than femoral artery cannulation. Conclusion Compared to FF-ECMO, axillary cannulation was associated with similar 90-day mortality rates. The high rate of stroke associated with axillary artery cannulation requires further investigation.