Beta-Blockers and Mortality in Takotsubo Cardiomyopathy
Does beta-blocker use in the acute phase of Takotsubo cardiomyopathy (TC) lower short-term mortality?
This was a retrospective cohort study using a nationwide inpatient database in Japan between 2010 and 2014. Patients were admitted with a diagnosis of TC, and notable exclusion criteria were the presence of pheochromocytoma or myocarditis; status asthmaticus; prior myocardial infarction; significant valvular heart disease; use of intra-aortic balloon pump (IABP), extracorporeal membrane oxygenation (ECMO), or temporary pacing; use of inotropes or vasopressors; or starting beta-blocker on day 3 or later. Using 1:4 propensity score matching, 30-day in-hospital mortality was compared between patients who received beta-blocker therapy beginning on hospitalization day 1 or 2 (n = 422) and patients who did not receive a beta-blocker during hospitalization (control group, n = 1,688). The primary outcome was 30-day in-hospital mortality.
The mean age was 73.0 years (standard deviation, 11.2 years) and 81.5% of patients were female. In the treatment group, 89.1% of patients received only oral beta-blockers; 4.5% received initial intravenous beta-blockers followed by oral; and 6.4% received only intravenous beta-blockers. Median duration of beta-blocker therapy was 9 days (interquartile range, 6-15 days). After propensity score matching, baseline characteristics between the two groups were well balanced. Logistic regression analysis of propensity score-matched patients failed to show a significant association between early beta-blocker use and 30-day in-hospital mortality rates (2.4% vs. 2.0%, p = 0.70). There were no significant differences in post-admission cardiovascular complications (ventricular tachycardia/ventricular fibrillation, second- or third-degree atrioventricular block, cerebral infarction). Early beta-blocker use in an extended cohort, defined as patients who were hemodynamically unstable (requiring inotropes/vasopressors or IABP/ECMO), also did not show a significant effect on the primary endpoint of 30-day in-hospital mortality (2.9% vs. 3.1%, p = 0.89).
The authors concluded that early beta-blocker use is not associated with lower in-hospital mortality in patients with TC.
One hypothesis for the pathogenesis and treatment of TC is that it is catecholamine-mediated cardiac dysfunction, and that the use of beta-blockers could decrease the detrimental effects of excess adrenergic stimulation. Two smaller studies previously showed that treatment with beta-blockers at the time of TC diagnosis or before admission were not significantly associated with more rapid improvement in myocardial dysfunction or associated with the severity of myocardial dysfunction, respectively. This retrospective study adds to data suggesting that early beta-blockers are not associated with improved clinical outcomes in TC. Given the retrospective design of this study, a randomized controlled trial is needed to confirm these findings.
< Back to Listings