Left atrium passive ejection fraction is the most sensitive index of type 2 diabetes mellitus-related cardiac changes

Progress in Cardiac Magnetic Resonance Feature Tracking for Evaluating Myocardial Strain in Type-2 Diabetes Mellitus

The global prevalence of type-2 diabetes mellitus (T2DM) has caused harm to human health and economies. Cardiovascular disease is one main cause of T2DM mortality. Increased prevalence of diabetes and associated heart failure (HF) is common in older populations, so accurately evaluating heart-related injury and T2DM risk factors and conducting early intervention are important. Quantitative cardiovascular system imaging assessments, including functional imaging during cardiovascular disease treatment, are also important. The left-ventricular ejection fraction (LVEF) has been traditionally used to monitor cardiac function; it is often preserved or increased in early T2DM, but subclinical heart deformation and dysfunction can occur. Myocardial strains are sensitive to global and regional heart dysfunction in subclinical T2DM. Cardiac magnetic resonance feature-tracking technology (CMR-FT) can visualize and quantify strain and identify subclinical myocardial injury for early management, especially with preserved LVEF. Meanwhile, CMR-FT can be used to evaluate the multiple cardiac chambers involvement mediated by T2DM and the coexistence of complications. This review discusses CMR-FT principles, clinical applications, and research progress in the evaluation of myocardial strain in T2DM.

Three-Dimensional Automated, Machine-Learning-Based Left Heart Chamber Metrics: Associations with Prevalent Vascular Risk Factors and Cardiovascular Diseases

Background. Three-dimensional transthoracic echocardiography (3DE) powered by artificial intelligence provides accurate left chamber quantification in good accordance with cardiac magnetic resonance and has the potential to revolutionize our clinical practice. Aims. To evaluate the association and the independent value of dynamic heart model (DHM)-derived left atrial (LA) and left ventricular (LV) metrics with prevalent vascular risk factors (VRFs) and cardiovascular diseases (CVDs) in a large, unselected population. Materials and Methods. We estimated the association of DHM metrics with VRFs (hypertension, diabetes) and CVDs (atrial fibrillation, stroke, ischemic heart disease, cardiomyopathies, >moderate valvular heart disease/prosthesis), stratified by prevalent disease status: participants without VRFs or CVDs (healthy), with at least one VRFs but without CVDs, and with at least one CVDs. Results. We retrospectively included 1069 subjects (median age 62 [IQR 49−74]; 50.6% women). When comparing VRFs with the healthy, significant difference in maximum and minimum indexed atrial volume (LAVi max and LAVi min), left atrial ejection fraction (LAEF), left ventricular mass/left ventricular end-diastolic volume ratio, and left ventricular global function index (LVGFI) were recorded (p < 0.05). In the adjusted logistic regression, LAVi min, LAEF, LV ejection fraction, and LVGFI showed the most robust association (OR 3.03 [95% CI 2.48−3.70], 0.45 [95% CI 0.39−0.51], 0.28 [95% CI 0.22−0.35], and 0.22 [95% CI 0.16−0.28], respectively, with CVDs. Conclusions. The present data suggested that novel 3DE left heart chamber metrics by DHM such as LAEF, LAVi min, and LVGFI can refine our echocardiographic disease discrimination capacity.

Left atrial structure and function are associated with cardiovascular outcomes independent of left ventricular measures: a UK Biobank CMR study

AIMS

We evaluated the associations of left atrial (LA) structure and function with prevalent and incident cardiovascular disease (CVD), independent of left ventricular (LV) metrics, in 25 896 UK Biobank participants.

METHODS AND RESULTS

We estimated the association of cardiovascular magnetic resonance (CMR) metrics [LA maximum volume (LAV), LA ejection fraction (LAEF), LV mass : LV end-diastolic volume ratio (LVM : LVEDV), global longitudinal strain, and LV global function index (LVGFI)] with vascular risk factors (hypertension, diabetes, high cholesterol, and smoking), prevalent and incident CVDs [atrial fibrillation (AF), stroke, ischaemic heart disease (IHD), myocardial infarction], all-cause mortality, and CVD mortality. We created uncorrelated CMR variables using orthogonal principal component analysis rotation. All five CMR metrics were simultaneously entered into multivariable regression models adjusted for sex, age, ethnicity, deprivation, education, body size, and physical activity. Lower LAEF was associated with diabetes, smoking, and all the prevalent and incident CVDs. Diabetes, smoking, and high cholesterol were associated with smaller LAV. Hypertension, IHD, AF (incident and prevalent), incident stroke, and CVD mortality were associated with larger LAV. LV and LA metrics were both independently informative in associations with prevalent disease, however LAEF showed the most consistent associations with incident CVDs. Lower LVGFI was associated with greater all-cause and CVD mortality. In secondary analyses, compared with LVGFI, LV ejection fraction showed similar but less consistent disease associations.

CONCLUSION

LA structure and function measures (LAEF and LAV) demonstrate significant associations with key prevalent and incident cardiovascular outcomes, independent of LV metrics. These measures have potential clinical utility for disease discrimination and outcome prediction.

Atrioventricular coupling and left atrial abnormality in type 2 diabetes mellitus with functional mitral regurgitation patients verified by cardiac magnetic resonance imaging

BACKGROUND

Functional mitral regurgitation (FMR) in type 2 diabetes mellitus (T2DM) patients induced by left ventricular (LV) enlargement and mitral valve abnormality may aggravated the impairment in left atrial (LA) compliance. Thus, this study aimed to depict how FMR and LV dysfunction affect LA compliance in T2DM patients with FMR.

MATERIALS AND METHODS

A total of 148 patients with T2DM and 49 age- and sex-matched normal controls underwent cardiac magnetic resonance examination. LA longitudinal strain and LA and LV functional indices were compared among controls and different T2DM patients. The multivariate analysis was used to identify the independent indicators of LA longitudinal strain.

RESULTS

T2DM Patients without FMR had a lower total LA empty fraction (LAEF) compared with the controls (all P < 0.05). T2DM patients with mild and moderate FMR showed increased LA volume (LAV) and LV volume while decreased LAEF, LA strain, and LV ejection fraction (P < 0.05). T2DM patients with severe FMR showed markedly increased LAV and LV volume while decreased LAEF, LA strain, and LVEF (P < 0.05). In T2DM patients with FMR, reservoir strain (εs) was independently correlated with LV end-diastolic volume (LVEDV) (β = - 0.334) and regurgitation degree (β = - 0.256). The passive strain (εe) was independently correlated with regurgitation degree (β = - 0.297), whereas the active strain (εa) was independently correlated with LVESV (β = - 0.352) and glycated haemoglobin (β = - 0.279).

CONCLUSION

FMR may aggravate LA and LV dysfunction in T2DM patients. Regurgitation degree was an independent determinant of the εs and the εe, LVEDV was an independent determinant of the εs, and LVESV was an independent determinant of the εa in T2DM patients with FMR.

Diabetic cardiomyopathy: Clinical phenotype and practice

Diabetic cardiomyopathy (DCM) is a pathophysiological condition of cardiac structure and function changes in diabetic patients without coronary artery disease, hypertension, and other types of heart diseases. DCM is not uncommon in people with diabetes, which increases the risk of heart failure. However, the treatment is scarce, and the prognosis is poor. Since 1972, one clinical study after another on DCM has been conducted. However, the complex phenotype of DCM still has not been fully revealed. This dilemma hinders the pace of understanding the essence of DCM and makes it difficult to carry out penetrating clinical or basic research. This review summarizes the literature on DCM over the last 40 years and discusses the overall perspective of DCM, phase of progression, potential clinical indicators, diagnostic and screening criteria, and related randomized controlled trials to understand DCM better.

Left Ventricular Diastolic Function Studied with Magnetic Resonance Imaging: A Systematic Review of Techniques and Relation to Established Measures of Diastolic Function

Purpose: In recent years, cardiac magnetic resonance (CMR) has been used to assess LV diastolic function. In this systematic review, studies were identified where CMR parameters had been evaluated in healthy and/or patient groups with proven diastolic dysfunction or known to develop heart failure with preserved ejection fraction. We aimed at describing the parameters most often used, thresholds where possible, and correlation to echocardiographic and invasive measurements. Methods and results: A systematic literature review was performed using the databases of PubMed, Embase, and Cochrane. In total, 3808 articles were screened, and 102 studies were included. Four main CMR techniques were identified: tagging; time/volume curves; mitral inflow quantification with velocity-encoded phase-contrast sequences; and feature tracking. Techniques were described and estimates were presented in tables. From published studies, peak change of torsion shear angle versus volume changes in early diastole (−dφ′/dV′) (from tagging analysis), early peak filling rate indexed to LV end-diastolic volume <2.1 s⁻¹ (from LV time-volume curve analysis), enlarged LA maximal volume >52 mL/m², lowered LA total (<40%), and lowered LA passive emptying fractions (<16%) seem to be reliable measures of LV diastolic dysfunction. Feature tracking, especially of the atrium, shows promise but is still a novel technique. Conclusion: CMR techniques of LV untwisting and early filling and LA measures of poor emptying are promising for the diagnosis of LV filling impairment, but further research in long-term follow-up studies is needed to assess the ability for the parameters to predict patient related outcomes.

Compressed sensing acceleration of cardiac cine imaging allows reliable and reproducible assessment of volumetric and functional parameters of the left and right atrium

Objectives

To compare volumetric and functional parameters of the atria derived from highly accelerated compressed sensing (CS)–based cine sequences in comparison to conventional (Conv) cine imaging.

Methods

CS and Conv cine sequences were acquired in 101 subjects (82 healthy volunteers (HV) and 19 patients with heart failure with reduced ejection fraction (HFrEF)) using a 3T MR scanner in this single-center study. Time-volume analysis of the left (LA) and right atria (RA) were performed in both sequences to evaluate atrial volumes and function (total, passive, and active emptying fraction). Inter-sequence and inter- and intra-reader agreement were analyzed using correlation, intraclass correlation (ICC), and Bland-Altman analysis.

Results

CS-based cine imaging led to a 69% reduction of acquisition time. There was significant difference in atrial parameters between CS and Conv cine, e.g., LA minimal volume (LAVmin) (Conv 24.0 ml (16.7–32.7), CS 25.7 ml (19.2–35.2), p < 0.0001) or passive emptying fraction (PEF) (Conv 53.9% (46.7–58.4), CS 49.0% (42.0–54.1), p < 0.0001). However, there was high correlation between the techniques, yielding good to excellent ICC (0.76–0.99) and small mean of differences in Bland-Altman analysis (e.g. LAVmin − 2.0 ml, PEF 3.3%). Measurements showed high inter- (ICC > 0.958) and intra-rater (ICC > 0.934) agreement for both techniques. CS-based parameters (PEF AUC = 0.965, LAVmin AUC = 0.864) showed equivalent diagnostic ability compared to Conv cine imaging (PEF AUC = 0.989, LAVmin AUC = 0.859) to differentiate between HV and HFrEF.

Conclusion

Atrial volumetric and functional evaluation using CS cine imaging is feasible with relevant reduction of acquisition time, therefore strengthening the role of CS in clinical CMR for atrial imaging.

Key Points

• Reliable assessment of atrial volumes and function based on compressed sensing cine imaging is feasible.

• Compressed sensing reduces scan time and has the potential to overcome obstacles of conventional cine imaging.

• No significant differences for subjective image quality, inter- and intra-rater agreement, and ability to differentiate healthy volunteers and heart failure patients were detected between conventional and compressed sensing cine imaging.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-021-07830-z.