Interaction of Systolic Blood Pressure and Resting Heart Rate with Clinical Outcomes in Takotsubo Syndrome: Insights from the International Takotsubo Registry

AIMS: The present study aimed to determine the prognostic impact of resting heart rate (HR) and systolic blood pressure (SBP) in takotsubo syndrome (TTS). METHODS AND RESULTS: Patients from the International Takotsubo Registry with complete data on HR and SBP were enrolled. We analysed all-cause mortality and major adverse cardiac and cerebrovascular events (MACCE) in tertiles of HR (<77 b.p.m., 77-94 b.p.m., >94 b.p.m.) and SBP (<119 mmHg, 119-140 mmHg, >140 mmHg). In addition, linear splines with interactions between HR and SBP were analysed. The risk of all-cause mortality was higher in the second HR tertile (1.89, 1.15-3.10; P = 0.012) and the third HR tertile (3.01, 1.90-4.79; P < 0.001) than in the first tertile. Similar effects were observed for MACCE. Low SBP was related to an increased risk of all-cause mortality (P < 0.001) and MACCE (P = 0.002). In a multivariable analysis of all-cause mortality, at HR >70 b.p.m., every 1 b.p.m. increase in HR was associated with a 1.7% increase (P < 0.001), and every 1 mmHg increase in SBP up to 130 mmHg was associated with a 2% risk reduction (P < 0.001). The risk of all-cause mortality thus was particularly elevated when low SBP occurred together with high HR. CONCLUSIONS: High HR and low SBP are associated with an increased risk of all-cause mortality in TTS. HR reduction might be worthy of being investigated as a therapeutic strategy for this condition and high HR and low SBP can be used to evaluate risk in this acute presentation of TTS. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT01947621.