Outcomes for Impella versus intra-aortic balloon pump in acute myocardial infarction and cardiogenic shock by sex: insights from the National Inpatient Sample (2012-2015)

Background:
Early use of Impella for acute myocardial infarction (AMI) and cardiogenic shock (CS) was associated with greater survival benefit in women compared to men. Little is known about utilization trends and outcomes of Impella versus intra-aortic balloon pump (IABP) in real-world practice by sex.

Methods:
Data was extracted from the National Inpatient Sample (NIS) between 2012-2015 using ICD-9 and ICD-10 codes. Observations for cardiogenic shock requiring either Impella or IABP were included in the national utilization analysis. Statistical comparisons were done using chi-square test and logistic regression was controlled for age, hypertension, hyperlipidemia, diabetes, chronic kidney disease, chronic heart failure, and percutaneous coronary intervention. All analyses and statistical testing were performed on SAS 9.4 windows.

Results:
Between 2012-2015, there has been a rise in Impella implantation (98% men and 114% women) while IABP implantation has declined (6% men and 4% women). In AMI and CS, inpatient mortality was high (32%) for patients receiving IABP or Impella. Women receiving IABP had higher inpatient mortality compared to men receiving IABP (OR 1.20, 95%CI 1.12-1.29) while there was no significant difference with Impella (OR 1.11, 95%CI 0.89-1.40). Both men (OR 0.44, 95%CI 0.39-0.50) and women (OR 0.44, 95%CI 0.37-0.54) had significantly lower odds of inpatient mortality with Impella versus IABP after adjustment.

Conclusions:
The utilization of Impella is increasing compared to IABP especially in women. Real world findings support inpatient mortality benefits of Impella compared to IABP in both men and women for AMI and CS.