STEMI SHOCK outcomes with SCAI classification

Abstract

Abstract Background Patients with ST-elevation myocardial infarction who develop cardiogenic shock (STEMI-SHOCK) face significantly increased risk compared to those without shock. Mechanical circulatory support (MCS) devices are commonly utilized in STEMI-SHOCK patients, but the benefits of MCS remain uncertain. This study aims to apply the Society for Cardiovascular Angiography and Interventions (SCAI) shock classification system to STEMI-SHOCK patients, examining outcomes and identifying subgroups that may benefit from MCS. Purpose Our study assessed SHOCK severity in STEMI-SHOCK patients using the updated 2021 SCAI-SHOCK classification system and determined survival at various endpoints (30 days, 1 year, and 3 years), along with other outcomes such as vascular access complications and major adverse cardiac events, based on the severity class. Methods Patients with angiograms and indications of STEMI-SHOCK between 2012 and 2021 admitted to Liverpool Hospital Australia, were included after adjudication they had STEMI-SHOCK. Angiograms were eligible for adjudication if they met criteria for both STEMI and SHOCK. Each patient underwent individual adjudication by three researchers to confirm STEMI-SHOCK status. Patients were followed from the time of the first SHOCK diagnosis until censoring at the last follow-up. Data were retrieved from electronic and paper-based patient records. The primary outcome was 30-day survival, and secondary outcomes were 1-year and 3-year survival. Results The SCAI stages of 160 (Estimated 220) STEMI-SHOCK patients were determined, with 17 in Stage A, 39 in Stage B, 53 in Stage C, 25 in Stage D, and 26 in Stage E. Worse SCAI stages were associated with significantly lower 30-day, 1-year, and 3-year survival. No difference in survival between the time periods 2013-2015 and 2018-2021 was found. An eGFR < 60 millilitres/minute/1.73 meters^2 (hazard ratio [HR] 3.41; 95% confidence interval [CI] 1.18 – 9.92, p=0.024) and lactate greater than 4.15 millimoles/liter (HR 6.48; 95% CI [2.84 – 51.64], p=0.001) at shock were associated with lower 30-day and 3-year survival. Patients in the SCAI C subgroup treated with an IABP had significantly higher 1-year (p=0.001) and 3-year (p=0.001) survival compared to those not treated with an IABP. Conclusion The SCAI classification system successfully predicted short and long-term survival in STEMI-CS patients, with worse stages having progressively worse outcomes. No improvement in survival outcomes was observed in the overall SCAI C-E group of patients treated with mechanical support. However, patients in the SCAI C subgroup of SHOCK treated with mechanical support showed a statistically significant improvement in survival outcomes compared to those treated without mechanical support. Further studies with adequate sample sizes are required to investigate sub-populations of SCAI classes that may benefit from MCS devices.