Association Between 2D- and 3D-Speckle-Tracking Longitudinal Strain and Cardiovascular Magnetic Resonance Evidence of Diffuse Myocardial Fibrosis in Heart Transplant Recipients

Feasibility and prognostic value of tissue motion annular displacement in patients with heart transplantation

BACKGROUND

Tissue motion of mitral annular displacement (TMAD) assessment has proved to be an effective method for several cardiovascular diseases including hypertrophic cardiomyopathy, heart failure, non-ST-elevation myocardial infarction, etc. However, there are no studies exploring the feasibility of TMAD in heart transplantation (HT) recipients, and the predictive value of this parameter for adverse outcomes in these patients remains unknown. Consequently, this study aimed to evaluate the feasibility of TMAD in the evaluation of left ventricular (LV) systolic function in clinically well adult HT patients, and further investigate the prognostic value of TMAD.

METHODS

Echocardiography was performed in 155 adult HT patients and 49 healthy subjects. All the subjects were examined by conventional transthoracic two-dimensional echocardiography and two-dimensional speckle tracking echocardiography (2D-STE) with evaluation of the LV end-diastolic diameter, LV end-diastolic volume index, LV end-systolic volume index, interventricular septal thickness, left atrial diameter, mitral annular plane systolic excursion (MAPSE), LV ejection fraction (LVEF), TMAD and LV global longitudinal strain (LVGLS). The end point was defined as all-causes mortality or posttransplant related hospitalization during follow up. Cox proportional hazards regression was performed to evaluate the prognostic value of the parameters for predicting poor outcomes in HT patients.

RESULTS

A significant positive correlation was found between the measurements of TMAD and LVGLS (r = .714, p < .001). TMAD obtained by 2D-STE had good reproducibility. The LVGLS and TMAD were significantly lower in HT group than in control group (both p < .001). In HT patients, compared with event free group, adverse outcome group displayed reduced TMAD and LVGLS, and elevated age (p < .001, < .001, = .017, respectively). Patients with higher TMAD (> 9.1 mm) had comparatively better survival when stratified by cutoff value (log-rank p < .001). LVGLS and TMAD were independently associated with adverse outcomes in multivariable analysis (both p < .001).

CONCLUSION

Assessment of TMAD is effective for evaluating LV longitudinal systolic function and predicting adverse outcomes in clinically well adult HT patients.

Arrhythmic mitral valve prolapse: a practical approach for asymptomatic patients

Mitral valve prolapse (MVP) is usually regarded as a benign condition though the proportion of patients with a life-threatening arrhythmic MVP form remains undefined. Recently, an experts' consensus statement on arrhythmic MVP has proposed approaches for risk stratification across the spectrum of clinical manifestation. However, sudden cardiac death may be the first presentation, making clinicians focused to early unmasking this subset of asymptomatic patients. Growing evidence on the role of cardiac imaging in the in-deep stratification pathway has emerged in the last decade. Pathology findings have suggested the fibrosis of papillary muscles and inferobasal left ventricular wall as the malignant hallmark. Cardiac magnetic resonance, while of limited availability, allows the identification of this arrhythmogenic substrate. Therefore, speckle-tracking echocardiography may be a gateway to prompt referring patients to further advanced imaging investigation. Our review aims to summarize the phenotypic features linked to the arrhythmic risk and to propose an image-based algorithm intended to help stratifying asymptomatic MVP patients.

Recent Progresses in the Multimodality Imaging Assessment of Myocardial Fibrosis

Myocardial fibrosis, a common pathophysiological consequence of various cardiovascular diseases, is characterized by fibroblast activation and excessive deposition of extracellular matrix (ECM) collagen. Accumulating evidence indicates that myocardial fibrosis contributes to ventricular stiffness, systolic and diastolic dysfunction, and ultimately leads to the development of heart failure (HF). Early detection and targeted treatment of myocardial fibrosis is critical to reverse ventricular remodeling and improve clinical outcomes in patients with cardiovascular diseases. However, despite considerable progresses made in understanding molecular mechanisms of myocardial fibrosis, non-invasive imaging to assess myocardial fibrosis and guide clinical treatment is still not widely available, limiting the development of innovative treatment strategies. This review summarizes recent progresses of imaging modalities for detecting myocardial fibrosis, with a focus on nuclear medicine, echocardiography and cardiac magnetic resonance (CMR).

Usefulness of Longitudinal Strain to Assess Cancer Therapy-Related Cardiac Dysfunction and Immune Checkpoint Inhibitor-Induced Myocarditis

Longitudinal strain (LS) measured by echocardiography has been reported to be useful not only for the diagnosis and risk stratification of various cardiac diseases, but also in cardio-oncology. Most previous studies have been conducted on patients undergoing treatment with anthracyclines and human epidermal growth factor receptor 2-targeted therapies. Existing guidelines recommend that global LS (GLS) should be measured before and after the administration of cancer drugs. This recommendation is based on many reports showing that a decline in GLS is indicative of early or mild cancer therapy-related cardiac dysfunction. The main purpose of this article is to provide insight into the importance of LS in patients undergoing cancer treatment and highlight the role of LS evaluation in patients undergoing immune checkpoint inhibitor (ICI) treatment, which is being used with increasing frequency. Among cancer drug therapies, immune checkpoint inhibitors (ICIs) have an important place in cancer treatment and are used for the treatment of many types of cancer. Although the efficacy of ICIs in cancer treatment has been reported, immune-related adverse events (irAEs) have also been reported. Among these irAEs, cardiovascular complications, although rare, are recognized as important adverse events that may result in ICI treatment discontinuation. Myocarditis is one severe adverse event associated with ICIs, and it is important to standardize diagnostic and therapeutic approaches to it. Several studies have reported a relationship between LS and cardiac complications associated with ICIs which may contribute to the early diagnosis of ICI-induced cardiac complications.

Detection of myocardial fibrosis: Where we stand

Myocardial fibrosis, resulting from the disturbance of extracellular matrix homeostasis in response to different insults, is a common and important pathological remodeling process that is associated with adverse clinical outcomes, including arrhythmia, heart failure, or even sudden cardiac death. Over the past decades, multiple non-invasive detection methods have been developed. Laboratory biomarkers can aid in both detection and risk stratification by reflecting cellular and even molecular changes in fibrotic processes, yet more evidence that validates their detection accuracy is still warranted. Different non-invasive imaging techniques have been demonstrated to not only detect myocardial fibrosis but also provide information on prognosis and management. Cardiovascular magnetic resonance (CMR) is considered as the gold standard imaging technique to non-invasively identify and quantify myocardial fibrosis with its natural ability for tissue characterization. This review summarizes the current understanding of the non-invasive detection methods of myocardial fibrosis, with the focus on different techniques and clinical applications of CMR.