Impact of symptom duration and mechanical circulatory support on prognosis in cardiogenic shock complicating acute myocardial infarction.

Background: Mortality rates in patients with cardiogenic shock complicating acute myocardial infarction (AMICS) remain high despite advancements in AMI care. Our study aimed to investigate the impact of prehospital symptom duration on the prognosis of AMICS patients and those receiving mechanical circulatory support (MCS).

Methods and results: We conducted a retrospective cohort study with data registered in the Netherlands Heart Registration. A total of 1,363 patients with AMICS who underwent percutaneous coronary intervention between 2017 and 2021 were included. Patients presenting after out-of-hospital cardiac arrest were excluded. Most patients were male (68%), with a median age of 69 years (IQR 61-77), predominantly presenting with ST-elevation myocardial infarction (86%). The overall 30-day mortality was 32%. Longer prehospital symptom duration was associated with a higher 30-day mortality with the following rates: < 3 h, 26%; 3-6 h, 29%; 6-24 h, 36%; ≥ 24 h, 46%; p < 0.001. In a subpopulation of AMICS patients with MCS (n = 332, 24%), symptom duration of > 24 h was associated with significantly higher mortality compared to symptom duration of < 24 h (59% vs 45%, p = 0.029). Multivariate analysis identified > 24 h symptom duration, age and in-hospital cardiac arrest as predictors of 30-day mortality in MCS patients.

Conclusion: Prolonged prehospital symptom duration was associated with significantly increased 30-day mortality in patients presenting with AMICS. In AMICS patients treated with MCS, a symptom duration of > 24 h was an independent predictor of poor survival. These results emphasise the critical role of early recognition and intervention in the prognosis of AMICS patients.