Non-St Segment Elevation Myocardial Infarction Complicated by Cardiogenic Shock in the Elderly: Role of Percutaneous Coronary Intervention

Abstract

Cardiogenic shock (CS) in patients with non-ST segment elevation myocardial infarction (NSTEMI) is associated with significant mortality. The role of percutaneous coronary intervention (PCI) and intra-aortic balloon pump in elderly patients (IABP) with CS is not well described. METHODS: We used data from the National Inpatient Sample for the years 2012 to 2014. We included patients with a primary diagnosis of NSTEMI and age >75 years and have diagnoses of cardiogenic shock. Patients were divided into two groups; those who received PCI versus those who received medical therapy alone. Baseline characteristics and in-hospital mortality were compared between the two groups. Multivariable logistic regression was used to adjust mortality for age, sex, AKI, Charlson index and the use of IABP and mechanical ventilation. RESULTS: A total of 16,875 weighted discharges were included. Among them 3,895 (23.1%) received PCI. Patients in the PCI group were younger, had less acute kidney injury, dementia, lower Charlson score and more likely to receive IABP. Mortality in the PCI group was 32% versus 43.5% in the medical therapy group, p<0.001. In multivariable logistic regression, PCI was associated with lower likelihood of in-hospital mortality, OR: 0.61 (95% CI: 0.51-0.73). IABP was also associated with lower odds of mortality, OR: 0.77 (95% CI: 0.65-0.92). Other predictors of mortality included the use of mechanical ventilation and age. CONCLUSIONS: Among the elderly hospitalized for NSTEMI and complicated with cardiogenic shock, PCI and IABP use were associated with lower odds of in-hospital mortality. Further studies are needed to examine barriers of PCI utilization in this group. CLINICAL IMPLICATIONS: Cardiogenic shock in the elderly with NSTEMI is associated with high mortality especially in those who did not receive PCI. PCI was associated with lower mortality rates even after adjustment to important co-variables. Whether the lower mortality is the direct result of revascularization or due to patients' characteristics remains to be examined.