Trends in hospitalization for takotsubo cardiomyopathy in the United States

Abstract

Background: Takotsubo (or stress induced) cardiomyopathy is characterized by transient left ventricular systolic dysfunction. Recent trends in patient volume, characteristics, and outcomes in the United States are unknown.

Methods: Using 2007-2012 National Inpatient Sample data, we identified 22,005 adults (≥18 years) with a primary and 31,942 adults with a secondary discharge diagnosis of takotsubo cardiomyopathy (International Classification of Diseases, Ninth Revision, code 429.83) who underwent diagnostic coronary angiography.

Results: During 2007 to 2012, the incidence of takotsubo cardiomyopathy increased over 3-fold: 52/million discharges in 2007 to 178/million in 2012 (P < .001). We found a temporal increase in the prevalence of cardiac arrest, cardiogenic shock, cardiovascular risk factors (diabetes, hypertension), and psychiatric disorders (P trend < .0001 for all). In-hospital mortality was 1.1% and remained unchanged over this period (P = .22). Compared to the primary diagnosis group, mortality in the secondary diagnosis group was higher (1.1% vs 3.2%) and was associated with higher incidence of cardiogenic shock, cardiac arrest, and respiratory failure. Men represent 8% of patients in the primary diagnosis group and 12% in the secondary group. In both groups, men had a higher incidence of shock, cardiac arrest, and respiratory failure. Although their mortality was higher than women in the primary group (3.0% vs 0.9%, adjusted odds ratio 3.85, 1.74-8.51), it was comparable in the secondary group (4.8% vs 3.0%).

Conclusions: We found a marked increase in the hospitalization for takotsubo cardiomyopathy in the United States in recent years, suggesting higher incidence than prior reports. Although outcomes have remained favorable, there is an increasing burden of cardiovascular and psychiatric disorders in this population with growing cost of care. Risk of mortality is higher in men and in patients with underlying critical illness. The excess mortality in these groups appears to be mediated by greater severity of disease.

Figure 1

Flowsheet for the patient selection process in the present study

Figure 2

Calendar-year trends in hospitalization for takotsubo cardiomyopathy (number per 1 million discharges) in the United States – primary discharge diagnosis, secondary discharge diagnosis and overall.

Figure 3

Multivariate logistic regression for mortality with adjustment for patient characteristics (c-statistic − 0.88)