Long-term functional cardiac changes in takotsubo syndrome

Abstract Background Takotsubo syndrome has long been thought to be a benign condition once the acute event has been overcome. However, an increasing number of studies suggest that there might be long-term consequences. The aim of the present study was to evaluate long term functional cardiac changes in patients after Takotsubo Syndrome. Methods In the present study, a total of 131 TTS patients were prospectively included and age and gender matched with 131 ACS patients. Out of this cohort, a total of 66 patients (TTS: N=33, ACS: N=33) without any known respiratory diseases (e.g. Asthma or COPD) had a follow-up examination one to six months after the index event, including cardiopulmonary exercise testing (CPET) and echocardiography. CPET indices were compared between TTS and ACS patients in those who achieved an RER of at least 1.05. Results Mean age of patients was 65.4 in the TTS group and 65.0 in the ACS group (p=0.541). In each group, 118 (90%) patients were female. At follow-up, TTS patients had a significantly higher LVEF (%, TTS: 59 [56 to 63] vs ACS: 56.5 [51 to 60], p<0.001) and significantly lower levels of BNP (ULN, TTS: 0.5 [0.2 to 0.9] vs ACS: 1.0 [0.5 to 2.6], p<0001), compared to TTS patients. TTS patients were significantly more frequently suffering from persistent symptoms compared to ACS patients (TTS: 78 [60%] vs. ACS: 60 [45.8%], p=0.035, figure 1). Twenty-four TTS Patients (72%) had an RER over 1.05 and were age and gender matched with 24 ACS patients. VO2max was comparable between the two groups (TTS: 20.2 [±5.4] vs ACS: 18.9 [±7.6], p=0.47) as well as Peak Mets (TTS: 5.7 (±1.6) vs ACS: 5.5 (±1.9), p=0.68). However, there was a trend towards a lower oxygen pulse in TTS compared to ACS patients (TTS: 9.4 [±2.2] vs ACS: 10.9 [±3.1], p=0.055) and a significant higher oxygen cost of work (ΔV’O2/ΔW, TTS: 12.9 [11.3 to 15.5] vs ACS: 10.9 [9.7 to 12.2], p=0.019). Conclusion TTS patients were more frequently suffering from persistent symptoms compared to ACS patients. Moreover, TTS patients demonstrated long-term functional cardiac changes reflected in impaired CPET parameters comparable to or worse than those of ACS patients. These findings highlight the long-term consequences of TTS and further challenge the concept that TTS is a benign disease.