The right ventricular dysfunction and ventricular interdependence in patients with DM: assessment using cardiac MR feature tracking

Biventricular Dysfunction and Ventricular Interdependence in Patients With Pulmonary Hypertension: A 3.0-T Cardiac MRI Feature Tracking Study

BACKGROUND

Pulmonary hypertension (PH) results in right ventricular (RV) dysfunction, subsequently leading to left ventricular (LV) impairment. The mechanism underlying ventricular interdependence is largely uninvestigated.

PURPOSE

To explore the biventricular dysfunction and the ventricular interdependence in PH patients.

STUDY TYPE

Retrospective.

POPULATION

One hundred and seven PH patients (mean pulmonary artery pressure >20 mmHg) and 72 age- and sex-matched controls with cardiac magnetic resonance imaging (MRI) studies.

FIELD STRENGTH/SEQUENCE

3.0 T/balanced steady-state free precession sequence.

ASSESSMENT

LV and RV ejection fractions (EF) and RV and LV radial, circumferential, and longitudinal strains were assessed using commercial software. Strains were compared between controls, PH patients with preserved RVEF (RVEF ≥40%, N = 48), and PH patients with reduced RVEF (RVEF <40%, N = 59).

STATISTICAL TESTS

Chi-squared tests or Fisher's exact test, t tests or Mann-Whitney U test, one-way ANOVA with Bonferroni's post hoc correction or Kruskal-Wallis test, Pearson or Spearman correlation, and multivariable linear regression analysis. A two-tailed P < 0.05 was deemed statistically significant.

RESULTS

RV strain decreased sequentially from controls, through PH with preserved RVEF, to PH with reduced RVEF. PH patients with reduced RVEF had significantly lower LV strain, especially septal strain, and LV peak diastolic strain rate compared with both controls and PH patients with preserved RVEF. Multivariable analyses showed that RVEF was independently correlated with LV strain; furthermore, independent of RVEF, RV strain was significantly correlated with LV strain (LVGRS: β = 0.416; LVGCS: β = -0.371; LVGLS: β = 0.283).

DATA CONCLUSION

Subclinical impairment of RV function was found in PH with preserved RVEF. LV strain was impaired when RV was dysfunctional, which was associated with worsening RV strain. Therefore, while focusing on improving RV function, LV dysfunction in PH patients should also be monitored and treated early in order to slow the progression of the disease.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 3.

Biventricular Impairment and Ventricular Interdependence in Patients With Alcoholic Cardiomyopathy: Insights Through Cardiac Magnetic Resonance Imaging

BACKGROUND

Alcoholic cardiomyopathy (ACM) can lead to progressive cardiac dysfunction and heart failure, but little is known about biventricular impairment and ventricular interdependence (VI) in ACM patients.

PURPOSE

To use cardiac MRI to investigate biventricular impairment and VI in ACM patients.

STUDY TYPE

Retrospective.

POPULATION

Forty-one male patients with ACM and 45 sex- and age-matched controls.

FIELD STRENGTH/SEQUENCE

3.0 T/balanced steady-state free precession sequence, inversion recovery prepared echo-planar imaging sequence and phase-sensitive inversion recovery sequence.

ASSESSMENT

Biventricular structure, function, and global strain (encompassing peak strain [PS], peak systolic, and diastolic strain rate), PS of interventricular septal (IVS), microvascular perfusion (including upslope and time to maximum signal intensity [TTM]), late gadolinium enhancement (LGE), and baseline characteristics were compared between the controls and ACM patients.

STATISTICAL TESTS

Student's t-test, Mann-Whitney U test, Pearson's correlation, and multivariable linear regression models with a stepwise selection procedure. A two-tailed P value <0.05 was deemed as statistically significant.

RESULTS

Compared to control subjects, ACM patients showed significantly biventricular adverse remodeling, reduced left ventricle (LV) global upslope and prolonged global TTM, and the presence of LGE. ACM patients were characterized by a significant decline in all global strain within the LV, right ventricle (RV), and IVS compared with the controls. RV global PS was significantly associated with LV global PS and IVS PS in radial, circumferential, and longitudinal directions. Multivariable analyses demonstrated the longitudinal PS of IVS was significantly correlated with RV global radial PS (β = 0.614) and circumferential PS (β = 0.545). Additionally, RV global longitudinal PS (GLPS) was significantly associated with radial PS of IVS (β = -0.631) and LV GLPS (β = 1.096).

DATA CONCLUSION

ACM patients exhibited biventricular adverse structural alterations and impaired systolic and diastolic function. This cohort also showed reduced LV microvascular perfusion, the presence of LGE, and unfavorable VI.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 3.

Effects of diabetes mellitus and glycemic traits on cardiovascular morpho-functional phenotypes

BACKGROUND

The effects of diabetes on the cardiac and aortic structure and function remain unclear. Detecting and intervening these variations early is crucial for the prevention and management of complications. Cardiovascular magnetic resonance imaging-derived traits are established endophenotypes and serve as precise, early-detection, noninvasive clinical risk biomarkers. We conducted a Mendelian randomization (MR) study to examine the association between two types of diabetes, four glycemic traits, and preclinical endophenotypes of cardiac and aortic structure and function.

METHODS

Independent genetic variants significantly associated with type 1 diabetes, type 2 diabetes, fasting insulin (FIns), fasting glucose (FGlu), 2 h-glucose post-challenge (2hGlu), and glycated hemoglobin (HbA1c) were selected as instrumental variables. The 96 cardiovascular magnetic resonance imaging traits came from six independent genome-wide association studies. These traits serve as preclinical endophenotypes and offer an early indication of the structure and function of the four cardiac chambers and two aortic sections. The primary analysis was performed using MR with the inverse-variance weighted method. Confirmation was achieved through Steiger filtering and testing to determine the causal direction. Sensitivity analyses were conducted using the weighted median, MR-Egger, and MR-PRESSO methods. Additionally, multivariable MR was used to adjust for potential effects associated with body mass index.

RESULTS

Genetic susceptibility to type 1 diabetes was associated with increased ascending aortic distensibility. Conversely, type 2 diabetes showed a correlation with a reduced diameter and areas of the ascending aorta, as well as decreased distensibility of the descending aorta. Genetically predicted higher levels of FGlu and HbA1c were correlated with a decrease in diameter and areas of the ascending aorta. Furthermore, higher 2hGlu levels predominantly showed association with a reduced diameter of both the ascending and descending aorta. Higher FIns levels corresponded to increased regional myocardial-wall thicknesses at end-diastole, global myocardial-wall thickness at end-diastole, and regional peak circumferential strain of the left ventricle.

CONCLUSIONS

This study provides evidence that diabetes and glycemic traits have a causal relationship with cardiac and aortic structural and functional remodeling, highlighting the importance of intensive glucose-lowering for primary prevention of cardiovascular diseases.