1UniversitätsSpital Zürich Klinik für Kardiologie Zürich, Schweiz; 2UniversitätsSpital Zürich Universitäres Herzzentrum Zürich, Schweiz
Background:
Takotsubo Syndrome (TTS) has been historically considered a benign cardiac condition once the acute event has been resolved. Nevertheless, a growing body of research indicates that TTS may have long lasting implications for cardiac function. The aim of the present study was to evaluate long-term functional cardiac changes and their clinical implications after TTS.
Methods
A total of 159 TTS patients were prospectively included and age and gender matched with 159 ACS patients. Out of this cohort, all patients had consulting and echocardiography 50 to 200 days after the index event. Further, a total of 100 patients (46 with TTS and 54with ACS) without known respiratory diseases (such as Asthma or COPD) underwent cardiopulmonary exercise testing (CPET).Echocardiographic, CPET and rehospitalization rates were compared between the two groups.
Results
The mean age of patients was 65 years with 89% females. TTS patients had a higher prevalence of persisting symptoms, with particularly subjective low physical fitness beeing significantly increased. Cardiac rehospitalization rates were comparable (p=0.63). Echocardiographically, ACS patients exhibited lower left ventricular ejection fraction (LVEF), but a comparable prevalence of diastolic dysfunction compared to TTS patients (TTS: 40% vs ACS: 45%, p=0.366). A total of 52 patients (N TTS=26, N ACS=26) with an RER ≥ 1.1, no pulmonal diseases or evidence of pulmonary limitations and similar betablocker therapy were further analyzed. Peak metabolic equivalents were comparable, TTS patients had slightly lower peak oxygen consumption. TTS patients exhibited a significantly lower peak oxygen pulse (TTS: 8.68 vs ACS: 10.98 p=0.017), and a significantly increased oxygen cost of work (TTS: 13.80 vs ACS: 10.75, p<0.001). Moreover, there was a trend towards a lower ventilatory threshold in patients with TTS (p=0.068).
Conclusion
TTS patients, experienced persisting symptoms, similar cardiac rehospitalization rates compared to ACS, and sustained functional impairments reflected in compromised cardiopulmonary exercise testing parameters. Our results imply potential deconditioning and diminished submaximal exercise capabilities in TTS compared to ACS patients, suggesting a potential benefit for TTS patients from participation in cardiac rehabilitation programs.