V-A ECMO window of opportunity: identification of potential responders after an acute myocardial infarction complicated by cardiogenic shock

Abstract

Abstract Funding Acknowledgements None. Background V-A ECMO is designed to supply oxygen demands in patients with circulatory failure. Neutral results obtained in recent cardiogenic shock (CS) trials are probably related to the inclusion of a high proportion of patients with SCAI C stage, in many of whom, the device might not provide hemodynamic benefit despite the addition of inherent complications. Mechanical circulatory support could potentially have a role only for patients in SCAI D-E stages. Purpose Our aim was to explore the excess in mortality explained by a SCAI D-E stage at 12h, compared to a SCAI A-C stages at 12h, in patients admitted due to an acute myocardial infarction (AMI) complicated by CS (stages C-E at admission). Additionally, we aimed to identify those factors at admission—clinical, electrocardiographic, gasometrical, echocardiographic, and angiographic—which predict whether a patient will progress to SCAI D-E stages within the subsequent 12h from CS onset. Main Outcome: SCAI D and E stage at 12h. Methods We retrospectively analysed those patients admitted due to an AMI in SCAI C-E stages at admission, that had been prospectively screened for EUROSHOCK trial. We classified the patients in two groups: "SCAI A-C" and "SCAI D-E" at 12 hours and conducted a survival analysis. Additionally, we conducted a univariate and multivariate analysis including arrival potential predictors for SCAI D-E at 12 hours. Results A total of 72 patients were included. At admission 25 patien were in SCAI D-E. At 12 hours, 42 patients were in SCAI D-E, and this group showed a higher 30-day mortality rate particularly explained by an excess of mortality within the first 7 days (Figure 1). There were no significant differences between groups in most baseline characteristics (Table 1) such as age or gender. We observed a fewer proportion of previous chronic treatment with negative inotropes (betablockers and calcium channel antagonists) in the SCAI D-E group. Overall, anterior ST elevation on EKG was more prevalent among SCAI D-E group, median pH lower and median glycaemia and lactate higher. In the multivariate analysis after adjustment by confounders, the independently predictors at arrival for the development of a SCAI D-E stage at 12h were culprit LAD, cardiac arrest in the cath Lab, low initial median pH and final TIMI <3 result. Conclusions In a cohort of AMI patients complicated by CS, those patients who remained in a SCAI D-E stage at 12 hours from CS onset, compared to those in A-C, showed a 26% excess mortality at 30-day follow-up, especially during the first week. Patients who presented with LAD as the culprit artery, low initial pH, cardiac arrest in the cath lab, and got a TIMI <3 result after PCI were independently associated with the development of SCAI D-E within 12 hours from admission. Patients meeting these criteria could benefit from early selective mechanical support and be taken into consideration in the design of future randomized controlled trials.