Predictors of 30-day mortality and outcome in cases of myocardial infarction with cardiogenic shock treated by extracorporeal life support.

OBJECTIVES: The twin aims of this study were to identify the independent predictors of 30-day mortality and to analyse the outcomes of patients with cardiogenic shock (CS) associated with acute myocardial infarction (AMI) and necessitating extracorporeal life support (ECLS).
METHODS: The investigation was a single-centre, retrospective study of 77 patients who required ECLS for AMI with CS. A logistic regression analysis was performed to identify the independent variables associated with 30-day mortality.
RESULTS: Between February 2006 and November 2009, 745 patients in our establishment received ECLS. In the single-centre cohort, we retrospectively reviewed 77 patients who had required ECLS support for AMI with CS. The delay between AMI and CS ECLS was 15 ± 4 h. PCI was performed in 58 patients (75.3%) and isolated emergency CABG in 12 (15.6%). The remaining 7 patients (9.1%) did not undergo revascularization. ECLS duration averaged 9.8 ± 7.1 days. Nineteen patients were successfully weaned from ECLS (24%). Fifty-eight patients did not undergo or did not tolerate the weaning trial (76%). Forty patients died during ECLS support, 13 were implanted with a mono-ventricular (n = 9) or biventricular assist device (n = 4) and 5 were bridged to heart transplantation. Complications consisted primarily in pneumonia (51.3%) and acute renal failure requiring haemofiltration (46.1%). Pulmonary oedema occurred in 24 patients (31.6%) and major bleeding in 16 (21.33%). 30-day and in-hospital survival rates were, respectively, 38.9 and 33.8%. Multivariable analysis identified preimplantation lactate serum level, preimplantation creatinine serum level and previous cardiopulmonary resuscitation as independent predictors of 30-day mortality.
CONCLUSIONS: Prompt ECLS support is an effective strategy and provides a reasonable chance of survival in patients with AMI associated with profound CS. As shown in our results pertaining to predictive risk factors for 30-day mortality, reducing the duration of end-organ ischaemia is the keystone to management of this patient population. A major remaining challenge will consist in preventing pulmonary oedema following peripheral ECLS.