Racial differences in takotsubo cardiomyopathy outcomes in a large nationwide sample.

AIMS

Takotsubo cardiomyopathy (TC) is characterized by transient ventricular impairment, often preceded by emotional or physical stress. Racial differences affect the outcomes of several cardiovascular conditions; however, the effect of race on TC remains unknown. This investigation aims to assess the effect of race on in-hospital outcomes of TC in a large national sample.

METHODS AND RESULTS

We conducted a US-wide analysis of TC hospitalizations from 2006 to 2014 by querying the National Inpatient Sample database for the International Classification of Diseases-ninth Revision TC code, characteristics, and inpatient outcomes. Patients with a primary diagnosis of acute coronary syndrome were excluded to reduce selection bias. Caucasians were compared with African Americans (AA) for differences in baseline characteristics and in-hospital outcomes. Multivariate regression models were created to adjust for potential confounders. Of 97 650 TC patients, 83 807 (86.9%) were women, 89 624 (91.8%) identified as Caucasians, and 8026 (8.2%) as AA. The annual number of TC hospitalizations increased significantly from 2006 to 2014 in both races (from 335 to 21 265 annual cases, P < 0.001). In-hospital mortality initially increased (1-2% in 2006 to 5-6% in 2009, P < 0.001) and subsequently remained relatively stable around 5-7% with no significant difference between races. In unadjusted analysis, AA had more cardiac arrests [304 (3.8%) vs. 2569 (2.9%), P = 0.04], invasive mechanical ventilation [1671 (20.8%) vs. 15 897 (17.7%), P = 0.002], tracheostomies [242 (3%) vs. 1600 (1.8%), P = 0.001], acute kidney injuries [1765 (22%) vs. 14 608 (16.3%), P < 0.0001], and longer hospital stays [4.5 (3.2-4.8) vs. 3.8 (3.7-3.9) days, P < 0.0001] compared with Caucasians. After the adjustment for differences in age, gender, comorbidities (using the enhanced Charlson comorbidity index), hospital location/teaching status, and socio-economic factors, all differences were significantly attenuated or eliminated. Additionally, the adjusted risk was lower in AA compared with Caucasians, for cardiogenic shock [odds ratio (OR) 0.61 (0.47-0.78), P < 0.0001], mechanical ventilation [OR 0.8 (0.70-0.92), P = 0.002] and intraaortic balloon pump insertion [OR 0.63 (0.41-0.99), P = 0.04].

CONCLUSIONS

Our investigation is the first large US-wide analysis studying racial variations in TC outcomes. AA overall have more in-hospital complications; however, the differences are driven by racial disparities in demographics, comorbidities, and socio-economic factors.