Residual alterations of cardiac and endothelial function in patients who recovered from Takotsubo cardiomyopathy

Abstract

Introduction: Takotsubo cardiomyopathy (TCM) is characterized by transient left ventricle dysfunction. Hypothesis: A residual cardiac and endothelial dysfunction is present in patients who recovered from TCM. Methods: In this single-center prospective study, patients with prior TCM were included and followed for 6.4 ± 1.6 years. All underwent comprehensive cardiac function assessment, including tissue Doppler imaging (TDI) and 2-dimensional strain (2DS) echocardiography at their first visit. The number of circulating endothelial progenitor cells and levels of proangiogenic vascular endothelial growth factor (VEGF) and its receptor (VEGF-R) were measured. All measurements were compared with healthy controls. Results: Forty-two women (age 58. ±8.6 years, LVEF 58.1 ± 6.1%) comprised the TCM group. Patients post-TCM had significantly lower early velocities E′ (6 (5.0–8.0) vs. 9 (7.0–11.0) cm/s, p =.001) by TDI and higher E/E′ ratio (p =.002), lower LV global average longitudinal strain (LGS) (−18.9 ± 3.5% vs. −21.7 ± 2.3%, p =.002) and RV LGS (−20.1 ± 3.9% vs. −23.4 ± 2.8%, p =.003) were evident. There was a trend toward a higher VEGF-R (p =.09) along with decreased VEGF/VEGF-R ratio representing inadequate VEGF production. In-hospital mortality was not reported and only two non-cardiac deaths occurred at long-term follow-up. Conclusions: Altered TDI and 2DS indices suggest residual biventricular myocardial injury in post-TCM patients with the apparent LV function recovery. Inappropriate production of VEGF and VEGF-R were observed, suggesting a possible underlying endothelial dysfunction in these patients.