BS7 Neurohumoral Responses in Takotsubo Syndrome

Background We investigate if renin-angiotensin and endothelin-1 response pathways follow the same pattern of recovery as left ventricular ejection fraction in patients with takotsubo syndrome. Methods Ninety takotsubo syndrome patients [n=30 in each of ‘acute’,‘convalescent’ (3–5 months) and ‘recovered’ (> 1 year) groups] who were on minimal or no medication and were free of any significant cardiac/metabolic co-morbidities, and 30 healthy controls were studied. Serum concentrations of renin, angiotensin converting enzyme, angiotensin II, big endothelin-1, endothelin-1 were measured using commercially available ELISA, and BNP was measured using an immunoassay. Results Left ventricular ejection fraction was 38 ± 1.6 % in acute, 63 ± 2.0 % in convalescent and 64 ± 2.6 % in recovered takotsubo syndrome patients. As shown in the Figure, serum renin concentrations are persistently elevated after a takotsubo episode (p=0.03 vs controls). Angiotensin converting enzyme levels are significantly depressed during the acute phase compared to convalescent (p=0.004), recovered takotsubo (p=0.02) or controls (p=0.03). Angiotensin II is increased in takotsubo patients (p<0.001 vs controls) remaining persistently elevated long-term in the recovered group (p=0.03 vs controls). B-type natriuretic peptide concentrations remain elevated after a takotsubo episode compared to controls (p=0.003). Big endothelin-1 levels are unchanged, but endothelin-1 is significantly lower after takotsubo syndrome compared to controls (p=0.03). Conclusions Despite ‘normalisation’ of the left ventricular ejection fraction, there is long-term maladaptive activation of renin-angiotensin system in takotsubo syndrome patients. This suggests therapy aimed at modulating this pathway may be beneficial in the long-term.