Short-Term Temporal Changes in Myocardial Strain in Takotsubo Cardiomyopathy

Abstract

Background Takotsubo cardiomyopathy (TC) is an acute heart failure syndrome. Despite an often rapid recovery in left ventricular ejection fraction (LVEF), TC is associated with morbidity and mortality in select patients which may be due to persistent abnormalities in myocardial mechanics. Strain echocardiography quantifies myocardial deformation and is a sensitive marker of myocardial dysfunction. The aim of this study was to evaluate the short-term temporal changes in LVEF and myocardial deformation between presentation and close follow-up. Hypothesis Improvement in LVEF will occur prior to improvement in myocardial strain at short-term follow-up. Methods Patients with an ICD9/10 diagnosis code of TC were identified using the Northwestern University Enterprise Data Warehouse. All TC patients with echocardiograms at presentation and within 21 days of presentation were included. Two-dimensional speckle-tracking echocardiography (2DSTE) was performed using Tomtec Arena 2.21 software to assess LVEF, LV peak global longitudinal strain (GLS), global radial strain (GRS), global circumferential strain (GCS), as well as RV fractional area change (FAC) and peak free wall strain (FWS). Statistical analysis was performed using a paired samples Student's t-test with a p-value Results The study cohort included 80 patients with 80% females and mean age 65.6 ± 15.4 yrs. Patients were grouped by timing of follow-up echocardiogram: within 3 days, between 4-10 days, and between 11-21 days from presentation. Compared to baseline echocardiogram, there was significant improvement in LVEF (29.0% vs 37.6%, p = 0.001) and GLS (−10.6% vs −12.7%, p = 0.022) in patients with follow up echocardiograms within 3 days ( Table 1 ). Significant improvement in GCS (−15.3% vs −21.7%, p = 0.005) and GRS (24.2% vs 32.0%, p = 0.035) was not seen until 4-10 day follow up. At 21 day follow-up, significant improvement in RV FAC (27.5% vs 34.5%, p = 0.008) and RV FWS (−13.6% vs −18.4%, p = 0.002) was noted. Conclusion In our single-center cohort of TC patients, improvement in LVEF and GLS was noted relatively early after initial presentation. The improvement in GCS and GRS occurred later, indicating persistent cardiac dysfunction despite improved but not fully recovered LVEF. Furthermore, recovery in RV dysfunction occurred after improvement in all LV parameters. These persistent abnormalities in myocardial mechanics provide further insight into myocardial recovery in TC and the potential for improvements in risk stratification and management of these patients.