P322 Dynamic changes of left ventricular cardiac mechanics in takotsubo syndrome: a preliminary study
Authors: Prota C , Bellino M , Pucci M , Ferraioli D , Radano I , Benvenga R M , Silverio A , Iuliano G , Provenza G , Trotta R , Attisano T , Ciccarelli M , Baldi C , Galasso G , Citro R 
Published: January 2020

Abstract

Background
Takotsubo syndrome (TTS) is a transient left ventricular (LV) heart failure due to a reversible systolic dysfunction, usually recovering within days or weeks.

Purpose
To assess the dynamic changes of LV cardiac mechanics in a small cohort of TTS patients through the estimation of myocardial work, a newly developed non-invasive approach which allows correction of global longitudinal strain (GLS) for systolic blood pressure.

Methods
Twenty-four patients (mean age, 63.8 ± 8.4 yy; all female) with TTS diagnosis were retrospectively enrolled. Data from transthoracic two-dimensional and speckle-tracking echocardiography on admission and at 3 months follow-up were collected. Global myocardial work index (GWI, mmHg%) was calculated as the area of the LV pressure (LVP)-strain loop, where LVP was estimated noninvasively using a standard waveform fitted to valvular events and scaled to systolic blood pressure. From GWI we also assessed: global constructive work (GCW, mmHg%: work performed during shortening in systole + negative work during lenghtening in isovolumetric relaxation, IVR), global wasted work (GWW, mmHg%: negative workperformed by a segment during lengthening in systole + work performed during shortening in IVR) and global work efficiency (GWE, %: constructive work divided by the sum of constructive and wasted work). Baseline demographic and clinical features, including in-hospital adverse events as acute heart failure, cardiogenic shock and cardiac death, were also assessed.

Results
On overall population, a reduced ejection fraction (EF) and GLS were detected at hospital admission, with a substantial improvement at discharge and at follow-up (from 41.7 ± 8.3% to 54.5 ± 6.5% to 60.2 ± 4.6% for EF and from -11.7 ± 4.5% to -16.2 ± 4.2 to -21.3 ± 2.8% for GLS, respectively). Similarly, global MWI and MWE both showed a positive trend during the hospital course and at follow-up: MWI increased from 1048.8 ± 580.5 to 1522.4 ± 695.4 to 2021.1 ± 388.6 mmHg% and MWE from 78.7 ± 10.2 to 91.1 ± 4.6 to 94.5 ± 3.8 %. Increasing in MWE has been obtained through an improvement of GCW (from 1195.9 ± 537.2 to 1651.3 ± 700.3 to 2316.8 ± 490.6 mmHg%) and a contemporary decreasing in GWW (from 237.9 ± 137.2 to 106 ± 37.2 to 131.8 ± 150.8 mmHg%).
In-hospital adverse events occurred in 8 (50%) patients. Of note, despite EF and GLS at admission showed no significant differences, patients experiencing in-hospital adverse events showed lower value of acute MWI (725.6 ± 289.6 vs 1371.9 ± 632.1 mmHg%; p= 0.02) and MWE (73.6 ± 3.4 vs 83.8 ± 12.4%; p= 0.04) compared to patients without in-hospital complications.

Conclusion
Non-invasive assessment of myocardial work through echocardiographic strain-based technique could be useful to demonstrate the peculiar dynamic changes of cardiac mechanics and for a better risk stratification in TTS patients.
Abstract P322 Figure.