Long-Term Functional Limitations on Cardiopulmonary Exercise Testing in Emotion-Triggered Takotsubo Syndrome

Background: In patients with prior Takotsubo syndrome (TTS), long-lasting functional cardiac limitations were described as compared with normal subjects. Emotion-triggered Takotsubo syndrome (E-TTS) has more favorable outcomes than TTS preceded by a physical trigger or by no identifiable factors. The aim of the present study was to assess long-term cardiac functional limitations in a cohort of asymptomatic E-TTS patients. Methods: We enrolled n = 40 asymptomatic patients with a diagnosis of E-TTS. Cardiopulmonary exercise tests (CPET) were performed at 30 (12-40) months median follow-up from the acute event. A cohort of n = 40 individuals matched for age, sex, body mass index and comorbidities served as control. Results: Despite recovery of left ventricular ejection fraction, patients with prior E-TTS had lower peak VO2 and percentage of predicted peak VO2 (17.8 +/- 3.6 vs. 22.1 +/- 6.5; p < 0.001 and 75.2 +/- 14.1% vs. 100.6 +/- 17.1%, p < 0.001), VO2 at anaerobic threshold (AT) (11.5 [10.1-12.9] vs. 14.4 [12.5-18.7]; p < 0.001), peak O-2 pulse (9.8 +/- 2.5 vs. 12.9 +/- 3.5; p < 0.001) and higher VE/VCO2 slope (30.5 +/- 3.7 vs. 27.3 +/- 3.5; p < 0.001) compared with matched controls. We found no statistically significant differences in heart rate reserve (HRR), respiratory equivalent ratio (RER), mean blood pressure and peak PetCO(2) between patients and controls. Conclusions: Despite its favorable outcome, patients with E-TTS in our population were found to have subclinical long-term functional cardiac limitations as compared with a control cohort.