Clinical Outcomes of Cardiogenic Shock Complicating Acute Coronary Syndrome Treated with Percutaneous Coronary Intervention

Abstract

Background: Cardiogenic shock (CS) complicates 5-10% of patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) with high mortality despite contemporary treatments. Methods: Patients with ACS enrolled in the Melbourne Interventional Group registry (between 2005 and 2013) were divided into CS group (n = 636) and non-CS group (n = 12,548). Short and long-term outcomes were compared between the two groups. Results: Patients in the CS group compared with the non-CS group presented with more out-of-hospital cardiac arrest (OHCA) (31.1% vs. 2.2%), received more femoral access (96.2% vs. 88.5%), had more left main disease (6.7% vs. 0.6%), and greater lesion complexity (78% vs. 57.9%), and had lower overall procedural success (89.9% vs. 96.8%), all p < 0.01. In-hospital, 30-day and 12-month MACE (death, MI, target-vessel revascularisation) were higher in the CS group (45.9% vs. 3%), (47.3% vs. 4.8%), (54.4% vs. 12.4%), all p < 0.001 respectively. However, most of the mortality in the CS cohort occurred early while in-hospital. Long-term national death index-linked mortality was over 3-fold higher in the CS group (50.6% vs. 13.8%, p < 0.001). Kaplan-Meier survival analyses underscored lower survival of CS cohort compared to the non-CS cohorts over median of 4 year follow-up, log-rank p < 0.001. Within CS-subgroup analyses, those who were >75years of age, or who presented with OHCA, or non-STEMI or those with left main or multivessel PCI had poorer survival over long-term follow-up, all p < 0.01. Conclusion: Cardiogenic shock complicating ACS portends very poor short and long-term survival compared to haemodynamically stable patients undergoing PCI over the last decade.