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

Time Course of Left Ventricular Strain Assessment via Cardiovascular Magnetic Resonance Myocardial Feature Tracking in Takotsubo Syndrome

Background: Although takotsubo syndrome (TTS) is characterized by transient systolic dysfunction of the left ventricle (LV), the time course and mechanism of LV function recovery remain elusive. The aim of this study is to evaluate cardiac functional recovery in TTS via serial cardiac magnetic resonance feature tracking (CMR-FT). Methods: In this Japanese multicenter registry, patients with newly diagnosed TTS were prospectively enrolled. In patients who underwent serial cardiovascular magnetic resonance (CMR) imaging at 1 month and 1 year after the onset, CMR-FT was performed to determine the global circumferential strain (GCS), global radial strain (GRS) and global longitudinal strain (GLS). We compared LV ejection fraction, GCS, GRS and GLS at 1 month and 1 year after the onset of TTS. Results: Eighteen patients underwent CMR imaging in one month and one year after the onset in the present study. LV ejection fraction had already normalized at 1 month after the onset, with no significant difference between 1 month and 1 year (55.8 ± 9.2% vs. 58.9 ± 7.3%, p = 0.09). CMR-FT demonstrated significant improvement in GCS from 1 month to 1 year (-16.7 ± 3.4% vs. -18.5 ± 3.2%, p < 0.01), while there was no significant difference in GRS and GLS between 1 month and year (GRS: 59.6 ± 24.2% vs. 59.4 ± 17.3%, p = 0.95, GLS: -12.8 ± 5.9% vs. -13.8 ± 4.9%, p = 0.42). Conclusions: Serial CMR-FT analysis revealed delayed improvement of GCS compared to GRS and GLS despite of rapid recovery of LV ejection fraction. CMR-FT can detect subtle impairment of LV systolic function during the recovery process in patients with TTS.

Multidisciplinary approach in cardiomyopathies: From genetics to advanced imaging

Cardiomyopathies are myocardial diseases characterized by mechanical and electrical dysfunction of the heart muscle which could lead to heart failure and life-threatening arrhythmias. Certainly, an accurate anamnesis, a meticulous physical examination, and an ECG are cornerstones in raising the diagnostic suspicion. However, cardiovascular imaging techniques are indispensable to diagnose a specific cardiomyopathy, to stratify the risk related to the disease and even to track the response to the therapy. Echocardiography is often the first exam that the patient undergoes, because of its non-invasiveness, wide availability, and cost-effectiveness. Cardiac magnetic resonance imaging allows to integrate and implement the information obtained with the echography. Furthermore, cardiomyopathies' genetic basis has been investigated over the years and the list of genetic mutations deemed potentially pathogenic is expected to grow further. The aim of this review is to show echocardiographic, cardiac magnetic resonance imaging, and genetic features of several cardiomyopathies: dilated cardiomyopathy (DMC), hypertrophic cardiomyopathy (HCM), arrhythmogenic cardiomyopathy (ACM), left ventricular noncompaction cardiomyopathy (LVNC), myocarditis, and takotsubo cardiomyopathy.

Longitudinal Strain Patterns in Stress (Takotsubo) Cardiomyopathy: Evidence of Global Myocardial Injury and Incomplete Recovery

Stress cardiomyopathy develops after abrupt sympathetic stimulation, likely from catecholamine-induced myocardial toxicity. The evolution of myocardial strain during and after an episode have not been previously characterized. We aimed to determine whether preexisting contractile abnormalities may explain the observed regional dysfunction during an acute episode and to investigate the persistence of strain abnormalities after clinical recovery. We identified patients who were diagnosed with stress cardiomyopathy and had an echocardiogram performed before their episode, during their episode, and within 1 year after. The diagnosis was confirmed based on the absence of obstructive coronary lesions. Left ventricular (LV) longitudinal strain was calculated using speckle-tracking software and compared between baseline, episode, and follow-up echocardiograms. The LV strain analysis was performed on 23 patients. The LV ejection fraction was 64 ± 8.7% at baseline, 45 ± 12% during the episode, and 5 9 ± 10% after a median follow-up of 46 days. The LV global longitudinal strain was 24 ± 4.7% at baseline, 11 ± 4.9% during the episode, and 19 ± 4.6% after the follow-up. The mean ejection fraction (p <0.01) and global longitudinal strain (p <0.001) remained below baseline levels at follow-up. Longitudinal strain was reduced (<18%) in 80 ± 23% of myocardial segments during an episode and 41 ± 21% of myocardial segments at follow-up. During the acute episode, 35 ± 6% of the abnormal segments were in the base, outside of the region of ballooning. Our findings suggests that stress cardiomyopathy is associated with global rather than regional myocardial injury and that contractile abnormalities persist after clinical improvement. These findings challenge our previous understanding of stress cardiomyopathy and may guide future pathophysiologic understanding of this complex disease.

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

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.