Outcomes Associated With Peripheral Artery Disease in Myocardial Infarction With Cardiogenic Shock

Background: Mortality rates for patients presenting with acute myocardial infarction (AMI) and cardiogenic shock (CS) remain high despite advances in revascularization strategies and mechanical circulatory support (MCS) devices. Objectives: To elucidate the association between comorbid peripheral artery disease (PAD) and outcomes in CS and AMI. Methods: PAD status was defined in Medicare beneficiaries hospitalized with CS and AMI from 10/1/2015–6/30/2018. Primary outcomes ascertained through 12/31/2018 included in- and out-of-hospital mortality. Secondary outcomes included bleeding, amputation, stroke, and peripheral revascularization. Multivariable regression models with adjustment for confounders were used to estimate risk. Subgroup analyses included patients with MCS and those who underwent coronary revascularization. Results: Among 71,690 patients, 5.9% (N=4,259) had PAD. Mean age was 77.8±7.9 years, 58.7% were male and 84.3% were white. Cumulative in-hospital mortality was 47.2%, with greater risk among those with PAD (56.3% vs 46.6% without PAD; adjusted odds ratio [aOR] 1.50, 95% confidence interval [CI]: 1.40–1.59). PAD patients also had greater risk of in-hospital amputation (1.6% vs 0.2%; aOR 7.0, 95% CI: 5.26–9.37) and out-of-hospital mortality (67.9% vs 40.7%; adjusted hazard ratio: 1.78, 95% CI: 1.67–1.90). MCS was less frequently utilized in PAD patients (21.5% vs. 38.6% without PAD, p<0.001) and was associated with higher mortality and amputation risk. Findings were consistent in patients who underwent coronary revascularization. Conclusions: Among patients presenting with AMI and CS, PAD was associated with worse limb outcomes and survival. In addition to lower MCS utilization rates, those with PAD who received MCS had increased mortality, peripheral revascularization, and amputation rates.