Objective: To investigate the impact of shock index before Intra-Aortic Balloon Pump (IABP) implantation on recent prognosis of patients with cardiogenic shock (CS) complicating acute myocardial infarction (AMI) underwent primary percutaneous coronary intervention (PCI).
Methods: A total of 103 patients with CS complicating AMI admitted in our hospital from June 2014 to May 2019 who underwent primary PCI with IABP support were enrolled in the study. We collected the data according to the medical records and collected their clinical manifestation and laboratory examination, as well as 28-day mortality, and also calculated the shock index (ratio of heart rate to systolic blood pressure) before IABP implantation.
Results: Patients with higher SI at IABP insertion were associated with higher proportion of anterior infarction (81.5% vs. 61.2%, p = 0.022), previous history of PCI (24.1% vs. 8.16%, p = 0.030), culprit leision at left main (31.5% vs. 12.2%, p = 0.019), and final TIMI flow ≤ 2(55.5% vs. 26.5%, p = 0.003), invasive ventilation(40.7% vs. 20.4%, p = 0.026) as well as 28-day-mortality (81.5% vs. 61.2%, p = 0.022). SI at insertion may help predict recent outcome, with a cutoff value of 1.625, a sensitivity of 0.655 and a specificity of 0.708, and areas under the receiver-operating characteristic curve (AUCROC) was 0.713. On multiple analysis, SI, together with final TIMI flow, arterial pH and creatinine were independent predictive factors of recent prognosis among this population.
Conclusion: Among CS patients complicating AMI undergoing PCI with the support of IABP, higher SI before IABP implantation was associated with poorer prognosis, SI was an independent risk factor of 28-day mortality and may predict the 28-day outcome.
Keywords: Cardiogenic shock; IABP; acute myocardial infarction; prognosis; shock index.