Heparin-Induced Thrombocytopenia Is Associated with Higher in-Hospital Mortality after Left Ventricular Assist Device Placement: A Retrospective Cohort Study from National Inpatient sample2016-2019

Background:

Heparin is widely used to implant and maintain left ventricular assist devices (LVAD). Heparin-induced thrombocytopenia (HIT) is a severe complication that can hamper successful LVAD implantation or maintenance. The incidence and outcomes of HIT among hospitalized patients undergoing principal LVAD procedures are not well studied.

Purpose: We hypothesized that HIT is not associated with increased or decreased odds of in-hospital mortality in LVAD.

Methods:

This is a retrospective cohort study from principal LVAD hospitalizations between January 1, 2016, and December 31, 2019, using the 2016-2019 National Inpatient Sample (NIS), the largest all-payer public database of hospital care data in the United States. Our study sample included any hospitalizations with LVAD, as a principal procedure, aged 18 years or older, using the ICD 10 procedural codes validated in previous studies.

Results:

From 2016 to 2019, a total of 2924 (weighted N =13,205) hospitalizations with the principal procedure as LVAD were identified. Among them, 21.96% (n= 642) were females, and 78.04% (n = 2281) were males (p < 0.001), and 1.47 % (n=43) developed HIT. MeanThe mean age was 56.8 ± 13.3 years. Moreover, 60.7% of total LVAD were performed in Whites, 26.6% in Blacks, 7% in Hispanics, and 2% in Asians. 2111 (72.2%) hospitalizations had a Charlson comorbidity index (CCI) of three or higher. Compared to non-HIT, those who had HIT, were similar in age (mean age: 55.6 vs. 56.8; p=0.542), had lower CCI of three or higher (53.5% vs. 72.5%, p=0.015), but higher in-hospital mortality (23.3% vs 9.4%, p=0.006). Multivariate regression analysis showed that, compared with non-HIT, HIT had a significantly increased odds of in-hospital mortality (aOR: 3.37; 95% CI: 1.61, 7.01; p=0.001) after controlling for age, race, regional location of the hospital, hospital bed capacity, income, insurance provider, and Charlson comorbidity index. From 2016 to 2019, the annual incidence of principal LVAD per 100,000 hospitalizations have been stable at 10.1 in 2016, 10.8 in 2017, 10.2 in 2018 and 10.0 in 2019 (p-trend=0.475).

Conclusion:

The incidence of HIT in patients undergoing LVAD is low. However, HIT carries significantly higher in-hospital mortality in patients getting LVAD. The incidence of LVAD procedures has been stable over recent years.

Mitchell:Pfizer: Consultancy, Research Funding; BridgeBio: Consultancy; Myocardial Solutions: Research Funding; Abbott Laboratories: Research Funding; ,Children's Discovery Institute: Research Funding.