Regional disparity in outcomes among patients hospitalized for Takotsubo cardiomyopathy in the United States.

Introduction: Takotsubo cardiomyopathy (TTCM), an entity first described in Japan over two decades ago following myocardial stunning cases without evidence of coronary stenosis, has emerged as a unique entity with global recognition. We sought to investigate the extent and magnitude of regional variations in its outcomes.

Method: We used the National Inpatient Sample (NIS) of the Agency for Healthcare Research and Quality (2010-2014). Risk-adjusted rates of outcomes across the US geographical regions were calculated by fitting a Poisson regression model with a robust error variance under generalized estimating equations. Discrete numeric variables with over-dispersed count distributions -length of stay and continuous variables with a right skewed spread- cost of hospitalization were modeled using a generalized linear regression with a negative binomial function and gamma function respectively.

Result: We found significant regional variations in-patient mortality. While there was significantly higher risk of in-hospital death in the West (5.28 [4.34-6.44]) vs 4.40 [3.57-5.43] vs 4.10 [3.38-498] vs 4.78 [3.96-5.77]), there was a different pattern of variation in the length of days with longer hospital stay in the Northeast. Likewise, the risk-adjusted rate of non-routine home discharges was highest for Northeast. The West had the highest cost of hospitalization (West: $40,217 vs. South: $28,465) CONCLUSION: Significant geographic variation exists in the cost of hospitalization and in-hospital mortality of TTCM across the US. Understanding this variation requires a detailed understanding of the processes of care and identification of effective strategies to eliminate these disparities.