Impella Has Greater Mortality Benefit For Patients With Versus Without Cancer: Machine Learning Supported Propensity Score Case-Control Analysis of 101 Million+ Hospitalizations From 2016-2018

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Conference Proceeding

Publication Date


Publication Title

Journal of the Society for Cardiovascular Angiography & Interventions



This is the first nationally representative multi-year nation analysis of mortality, cost, and procedural volume of Impella mechanical circulatory support for patients with and without active cancer.


This case-control study of the above outcomes was conducted using the United States’ largest all-payer hospitalized dataset, the 2016-2018 National Inpatient Sample (NIS). Machine Learning-augmented Propensity Score adjusted multivariable regression (ML-PSr) was utilized, weighted by the NIS complex survey design, and adjusted for known confounders (including NIS-calculated mortality risk by DRG and the likelihood of undergoing Impella versus medical management).


Among 101,521,656 hospitalizations, 136,974 (0.05%) underwent Impella among whom 60,060 (0.02%) had active cancer. Patients with versus without cancer were significantly less likely to receive Impella in 2016 (0.01 versus 0.04%), 2017 (0.02 versus 0.02 versus 0.04%), and 2018 (0.03 versus 0.06%) concurrent with the linear increase in Impella procedures across all patients in the same time period (all p<0.001) 2018. Across all years, this disparity was similar in cardiogenic shock (1.62 versus 4.19%) and clinical severity-matching (by age and mortality risk: 3.77 versus 11.54%), though rates were comparable for septic shock (all p<0.001). There were no significant procedural disparities among patients with versus without cancer by sex, race, income, or urban density, but there were for regions (with the highest Impella volume in patients with cancer being done in the Northwest [5.96%] and Mountain [4.04%], p=0.026). In multivariable regression across all years, Impella significantly reduced mortality for patients with cancer (OR 0.39, 95%CI 0.19-0.82; p=0.012) along with an increased cost of $7,627.79 (95%CI 7394.51-7,861.07; p<0.001) for patients with versus without cancer.


This national propensity score analysis suggests Impella has a disproportionate mortality benefit for patients with versus without cancer, though the former receives them significantly less than the latter despite an otherwise comparable risk profile and gradually increasing rate of use.




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