P1728Cardiogenic shock patients: those with and those without out-of-hospital cardiac arrest are different clinical entities

Abstract

Introduction Cardiogenic shock (CS) due to myocardial infarction (MI) carries 30-day mortality rates as high as 50%. The vast majority of study cohorts assessing mortality in CS comprise both patients presenting with and without out-of-hospital cardiac arrest (OHCA). Patients with and without OHCA are likely to represent two distinctive entities, which may be problematic to combine in an intervention trial. Purpose The aim of the study was to compare CS due to MI patients presenting with and without OHCA in terms of patient characteristics and outcome. Methods In the period from 2010–2017 all patients admitted at two tertiary heart centres in Denmark with CS following MI were individually identified and validated through patient records. The two centres have a catchment area of 3.9 million citizens corresponding to two-thirds of the Danish population. Results A total of 1716 CS patients were identified, of which 42% presented with OHCA. OHCA patients were younger (mean 63 vs 67 years), more frequently male (85 vs 67%), had higher lactate concentration (median 6.2 vs 5.0 mmol/L) on admission and higher left ventricular ejection fraction (median 30 vs 25%) compared to patients without OHCA (p<0.0001 for all). Patients presenting with OHCA had lower 30-day mortality compared to patients without OHCA (49% vs. 57%, respectively, plogrank<0.0001, Figure). Cause of in hospital death differed markedly between the two groups. Not surprisingly, anoxic brain damage was the leading cause of in hospital death in the OHCA group (56%) and only seen in 4% of patients without OHCA. In contrast, cardiac failure was the main cause of death in hospital death among patients without OHCA (60%), compared to 27% in patients with OHCA (p<0.0001). Figure 1 Conclusion Among patients with CS due to MI, overall 30-day mortality was significantly lower in patients presenting with OHCA. Anoxic brain damage was the main cause of in hospital death among OHCA patients, whereas fatal heart failure prevailed in patients without OHCA. Combining these two groups in a single trial with one specific intervention seems inappropriate and likely to cause an imbalance in the signal-to-noise ratio. Acknowledgement/Funding The Danish Heart Foundation and a research grant from Abiomed