Hypoglycemia Associated with Worse Outcome in Takotsubo Cardiomyopathy: Perspective from the National Inpatient Sample and National Readmission Database

Stress induced cardiomyopathy, Takotsubo cardiomyopathy (TC) is characterized by transient left ventricular (LV) wall motion abnormality beyond the territories perfused by a single coronary artery. LV dysfunction is reversible, but the complications and mortality of TC is severe enough to compete with acute coronary artery syndrome. Especially, the role of blood glucose level in prognosis of TC has been controversial. Here, we sought to national in-hospital outcome and readmission rate of TC associated with glycemic control.

Methods:

We conducted a retrospective analysis of 3 years of the National Inpatient Sample (NIS) database, 2016 to 2018, and 2 years of Nationwide Readmission Database (NRD), 2018 to 2019. Study populations were selected using ICD-10 diagnosis code. Discharge-level weight analysis was used to produce a national estimate. We conducted multivariate regression analysis to calculate odds ratio with STATA 17.

Results:

During the study period, 116,735 of TC patients were discharged and 23.01% (n = 26,865) of them had diabetes mellitus (DM). Within TC population, 900 of patients (0.07%) experienced the hypoglycemia and only 2.22 % of them had DM. Hypoglycemia patients tended to be more male (20.00 % v 16.31 %), younger (mean age 59.25 ± 1.28 v 67.14 ± 0.09), less diabetic (2.22% v 23.18%) and have more CKD (1.67 % v 1.38 %). Hypoglycemia patients had more complications and worse outcomes associated with TC; higher in cardiogenic shock (12.22% v 6.13%), in-hospital mortality (13.89% v 5.83%) and longer length of stay (10.91± 0.73 v 6.78 ± 0.06). After adjusting for age, sex, race, DM and comorbid burden, hypoglycemia is associated with higher in-hospital mortality with TC (OR 2.60, 1.69 – 4.02, p < 0.0001). According to readmission database, hypoglycemia is not related with 30-days premature readmission (p = 0.996), but DM is associated with premature readmission after adjusting for age, sex and comorbidities (OR 1.18, 1.10 – 1.26, p < 0.0001).

Discussion/Conclusion:

As catecholamine plays a pivotal role in pathophysiology of TC, the sympathoadrenal system activation and a catecholamine release in response to hypoglycemia could reproduce a similar pathogenesis. Hypoglycemia is associated with worse outcome of TC, higher rate of complications, but not readmission rate. Perhaps improved risk stratification and optimal glycemic control may improve the outcome of TC.