TCT CONNECT-181 A Propensity Matched Analysis of Impella Use From a Large-Scale Claims Data: Influence of Analytic Methodology on Clinical Outcomes

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Conference Proceeding

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Journal of the American College of Cardiology


Background: A recently published large-scale, real-world study using the Premier Healthcare database designed to describe trends, outcomes, and cost across U.S. hospitals showed that Impella use was associated with higher rates of adverse events compared to the intra-aortic balloon pump (IABP) in patients undergoing percutaneous coronary intervention (PCI). The purpose of this study was to assess the impact of methodology on outcomes and interpretation of results from the same dataset.

Methods: The Premier Healthcare dataset was used to compare outcomes of patients undergoing PCI with Impella or IABP from 2004 to 2016. We used propensity score matching to overcome unadjusted confounders noted in the published analysis where <10% of the overall study population was treated with Impella and all patients were combined regardless of disease severity or indication.

Results: A total of 47,043 patients were identified (IABP 42,376; Impella 4,667) at 531 hospitals. Unadjusted mortality was similar between groups. The 1:1 propensity score matching on the basis of 21 covariates including patient demographics and comorbidities resulted in balanced Impella and IABP cohorts with 3,609 subjects in each group. There was no observed increased risk of AKI (1.4% vs. 1.0%; p = 0.1375), stroke (3.2% vs. 2.8%; p = 0.3033), bleeding requiring transfusion (4.3% vs. 3.7%; p = 0.1902), or death (24.4% vs. 22.9%; p = 0.1495) between Impella and IABP during the index hospitalization.

Conclusion: In contrast to a prior analysis from the same large claims dataset, using propensity matching as a methodologic approach to control for confounders, the risk of adverse clinical outcomes of patients undergoing Impella was not increased compared to IABP-assisted PCI. The interpretation of large claims data are subject to inherent methodological limitations. When conclusions can drastically impact patient care, these should be interpreted with caution especially in absence of clinical stratifications on the basis of procedural indication for hemodynamic support such as cardiogenic shock or acute myocardial infarction for PCI.

Categories: CORONARY: Complex and Higher Risk Procedures for Indicated Patients (CHIP)





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