Impact of left ventricular ejection fraction on mortality and use of mechanical circulatory support in non-ischaemic cardiogenic shock

Abstract

Abstract Background Evidence in non-ischaemic cardiogenic shock (CS), especially regarding prognostic markers and use of mechanical circulatory support (MCS), is scarce. Aim The aim of this study was to evaluate left ventricular ejection fraction (LVEF) as a prognostic marker as well as a factor to guide the use of MCS in non-ischaemic CS. Methods In this international observational study, patients with non-ischaemic CS (e.g. caused by severe de-novo or acute on chronic heart failure; but not by acute myocardial infarction) treated with or without MCS from 18 tertiary-care centers in five countries were enrolled. Cox regression models adjusted for age, sex, SCAI class, lactate, prior resuscitation, mechanical ventilation and pH were fitted to evaluate the association between LVEF and 30-day mortality as well as the interaction between MCS use, LVEF and 30-day mortality. Results A total of 807 patients were enrolled, of whom 387 (47,9%) were treated with and 418 (52.1%) without MCS; mean age was 63 [interquartile range (IQR) 51.5–72) years, 601 (74.5%) were male, 486 (60.2%) had acute on chronic heart failure, 221 (32.7%) had an ischaemic cardiomyopathy and 277 (34.5%) had prior cardiac arrest. The baseline LVEF was 20 (IQR 15–30) % and baseline lactate was 4.9 (IQR 2.6–8.5) mmol/l. There was no significant association between LVEF and 30-day mortality risk [hazard ratio (HR) 0.95, 95% confidence interval (CI) 0.74–1.22 if LVEF was considered as a continuous variable; HR 1.09, 95% CI 0.83–1.44 if LVEF was considered as a categorical variable with ≤20% vs. >20%]. However, there was a significant interaction between MCS use and LVEF, indicating a lower 30-day mortality risk with MCS use in patients with a depressed LVEF (HR 0.74, 95% CI 0.52–1.05, interaction-p = 0.04). Conclusion In this retrospective, multicenter, international study of patients with non-ischaemic CS, LVEF was not a predictor of 30-day mortality risk. However, we observed a significant interaction between MCS use and LVEF, indicating a lower morality risk with MCS use only in patients with a depressed LVEF. This provides rationale to use LVEF as a parameter to guide MCS therapy in non-ischaemic CS, and calls for a randomized trial on this topic. Funding Acknowledgement Type of funding sources: None.