Reperfusion Delays and Outcomes Among Patients With ST-Segment-Elevation Myocardial Infarction With and Without Cardiogenic Shock.

Background: Mortality remains high in patients with ST-segment-elevation myocardial infarction (STEMI) complicated by cardiogenic shock (CS), and early reperfusion has been shown to improve outcomes. We analyzed the association between first medical contact (FMC)-to-percutaneous coronary angiography time with mortality and major adverse cardiovascular events among patients with STEMI with and without CS.

Methods: We performed a retrospective analysis of the Vancouver Coastal Health Authority STEMI registry, including all patients with STEMI who received primary percutaneous coronary angiography between January 1, 2010, and December 31, 2020, and stratified them by presence or absence of CS at hospital arrival. The primary outcome was in-hospital mortality, the secondary outcome was in-hospital major adverse cardiovascular events, defined as a composite of the first occurrence of mortality, cardiac arrest, heart failure, intracerebral hemorrhage, cerebrovascular accident, or reinfarction. Mixed effects logistic regression with restricted cubic splines was used to estimate the relationships between FMC-to-device time and the outcomes in the CS and non-CS groups.

Results: 2929 patients were included, 9.4% (n=275) had CS. Median FMC-to-device time was 113.5 (interquartile range, 93.0-145.0) and 103.0 (interquartile range, 85.0-130.0) minutes for patients with CS and without CS, respectively. More patients with CS had FMC-to-device times above guideline recommendations (76.6% versus 54.1%, <0.001). Between 60 and 90 minutes, for each 10-minute increase in FMC-to-device time, absolute mortality for patients with CS increased by 4% to 7%, whereas for patients without CS, it increased by <0.5%.

Conclusions: Among patients with STEMI undergoing primary percutaneous coronary angiography, reperfusion delays among patients with CS are associated with significantly worse outcomes. Strategies to reduce FMC-to-device times for patients with STEMI presenting with CS are required.