Understanding patients with mechanical circulatory support for cardiogenic shock: The role of preceding cardiac arrest.

BACKGROUND: Patients receiving mechanical circulatory support (MCS) for myocardial infarction-related cardiogenic shock (AMICS) often have a preceding out-of-hospital cardiac arrest (OHCA). This study aimed to clarify the association between OHCA and patient profiles, clinical course and outcomes in this population.

METHODS: Using data from the Netherlands Heart Registration (NHR) PCI Registry, we examined a real-world AMICS cohort that underwent PCI and received MCS between 2017 and 2021 across nine hospitals. Patients were classified as OHCA or non-OHCA. Univariable and multivariable logistic regression analyses were used to identify predictors of 30-day mortality.

RESULTS: A total of 241 patients were included, with a mean age of 59.7 years and 78.0% being male. Half of the patients had a preceding OHCA (49.4%, n = 119). OHCA patients had a better pre-existing condition, a more acute presentation and less frequent multivessel disease. Thirty-day mortality rates were comparable between OHCA and non-OHCA patients (63.0% vs. 61.2%, p = 0.869). In the overall cohort, age, lactate, intubation and multivessel disease were independently associated with 30-day mortality. Among OHCA patients, age and lactate lost predictive value, whereas resuscitation longer than 30 min, an initial non-shockable rhythm, and multivessel disease were strongly associated with mortality. In non-OHCA patients, age, lactate and in-hospital cardiac arrest were predictive, while multivessel disease was not associated with 30-day mortality.

CONCLUSION: Although 30-day mortality rates were comparable, determinants of mortality differed between OHCA and non-OHCA patients. This study highlights the importance of distinguishing between OHCA and non-OHCA, and emphasises that OHCA alone should not be a contraindication for MCS or MCS-evaluating trials.