Long-term functional limitations on cardiopulmonary exercise testing in a cohort of patients with emotions-triggered takotsubo syndrome

Abstract Background In patients with prior Takotsubo syndrome (TTS), long lasting functional cardiac limitations were described as compared with normal subjects. Emotions–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=39 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=39 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 22.5 ± 6.5; P < 0.001 and 75.2 ± 14.1 % vs 100.6 ± 17.1%, P <0.001), VO2 at anaerobic threshold (AT) (11.1 [10.1–12.9] vs 14.4 [12.5–18.7]; P <0.001), peak O2 pulse (9.7 ± 2.5 vs 13.1 ± 3.5; P <0.001) and higher VE/VCO2 slope (30.4 ± 3.7 vs 27.2 ± 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 PetCO2 between patients and controls. Conclusions Despite their overall favorable outcome, asymptomatic patients with E–TTS were found to have long–term subclinical functional cardiac impairments. CPET proved to be a useful tool in the long–term evaluation of E–TTS patients after recovery of LVEF. Further studies are needed to fully clarify the origin of the detected CPET abnormalities as well as their prognostic relevance in patience with recovered E–TTS.