In-hospital mortality among patients with takotsubo cardiomyopathy: a study of the National Inpatient Sample 2008 to 2009.

BACKGROUND: Takotsubo cardiomyopathy is characterized by acute, reversible left ventricular apical ballooning. Little is known about the characteristics of patients with takotsubo cardiomyopathy who have in-hospital mortality. We sought to determine in-hospital mortality rate, complication rate, and characteristics of patients with in-hospital mortality related to takotsubo cardiomyopathy.

METHODS: Patients diagnosed with takotsubo cardiomyopathy in the National Inpatient Database Samples 2008 to 2009 using International Classification of Diseases, Ninth Revision, code 42983 were included in this study. Our primary outcome was in-hospital mortality. In patients with takotsubo cardiomyopathy, we assessed demographic factors, the prevalence and associated mortality of underlying critical illnesses (acute ischemic stroke, sepsis, acute renal failure, respiratory insufficiency, and noncardiac surgery), and acute complications (acute congestive heart failure, respiratory insufficiency with congestive heart failure, cardiogenic shock, ventricular fibrillation/cardiac arrest, and intraaortic balloon pump placement).

RESULTS: A total of 24,701 patients with takotsubo cardiomyopathy were identified. In-hospital mortality rate was 4.2%. A total of 21,994 patients (89.0%) were female. Male patients had a higher mortality rate than females (8.4% vs 3.6%, P < .0001). Age and race were not associated with mortality. Of patients with in-hospital mortality, 81.4% had underlying critical illnesses. Male patients with takotsubo had higher incidence of underlying critical illnesses than their female counterparts (36.6% vs 26.8%, P < .0001).

CONCLUSIONS: The presence of underlying critical illness was the main driver of mortality, as these patients comprised >80% of patients with in-hospital mortality. Male patients, who were significantly more likely to have underlying critical illness, had significantly higher mortality rates than female patients. The presence of underlying critical illness likely explains the higher mortality rate among male patients.