Diastolic Cardiac Function by MRI—Imaging Capabilities and Clinical Applications

Most cardiac studies focus on evaluating left ventricular (LV) systolic function. However, the assessment of diastolic cardiac function is becoming more appreciated, especially with the increasing prevalence of pathologies associated with diastolic dysfunction like heart failure with preserved ejection fraction (HFpEF). Diastolic dysfunction is an indication of abnormal mechanical properties of the myocardium, characterized by slow or delayed myocardial relaxation, abnormal LV distensibility, and/or impaired LV filling. Diastolic dysfunction has been shown to be associated with age and other cardiovascular risk factors such as hypertension and diabetes mellitus. In this context, cardiac magnetic resonance imaging (MRI) has the capability for differentiating between normal and abnormal myocardial relaxation patterns, and therefore offers the prospect of early detection of diastolic dysfunction. Although diastolic cardiac function can be assessed from the ratio between early and atrial filling peaks (E/A ratio), measuring different parameters of heart contractility during diastole allows for evaluating spatial and temporal patterns of cardiac function with the potential for illustrating subtle changes related to age, gender, or other differences among different patient populations. In this article, we review different MRI techniques for evaluating diastolic function along with clinical applications and findings in different heart diseases.

HbA1c and FIB-4 as Serologic Markers for the Risk of Progression of Stage A Heart Failure

Background The classic association of glycemic control as represented by glycosylated hemoglobin (Glyco% or HbA1c) with progression of micro and macro vascular clinical complications is well documented. However use of the advanced glycation end product (AGE) axis as a marker for early diastolic hemodynamic changes leading to clinical heart failure has been suggested but is less well characterized. This study explored the association between elevated Glyco% and Fibrosis 4 (FIB-4 a 4-component marker for liver fibrosis) values and worsening measures of diastolic cardiac function in order to assess their utility as early serologic markers in cardiovascular disease prevention. Methods and Results A Retrospective cohort analysis was conducted in 102 patients presenting to the Parkview Medical Center health system who had received a full resting echo characterized by normal systolic ejection fraction and clinical risk factors associated with stage A heart failure in conjunction with Glyco% and FIB-4 scores all within a 3-month time window. Using regression analysis measures of diastolic cardiac function were assessed in conjunction with rising Glyco% levels characterized as <6.5 and > 6.5 and FIB-4 scores after controlling for the presence of hypertension coronary artery disease and valvular heart disease. Glyco% levels > 6.5 were significantly associated with a higher E/e ratio and closely associated with an elevated left atrial volume index both indicative of elevated left atrial pressure as a sensitive marker for diastolic cardiac dysfunction. FIB-4 scores did not appear to be clinically associated with progression of diastolic dysfunction. Conclusions Glyco% long known to be a marker for metabolic glycemic control can also act as an early marker for identifying patients at increased risk for the progression of stage A heart failure. FIB-4 scores cannot.

Diastolic Cardiac Function Improvement by Liraglutide Is Mainly Body Weight Reduction Dependent but Independently Contributes to B-Type Natriuretic Peptide Reduction in Patients with Type 2 Diabetes with Preserved Ejection Fraction

Objectives. A single-arm prospective study was conducted among Japanese patients with type 2 diabetes having preserved ejection fraction. The aim was to investigate (1) whether liraglutide therapy could improve B-type natriuretic peptide (BNP) levels and diastolic cardiac function assessed by the E -wave to E ′ ratio ( E / E ′ ) using transthoracic echocardiography (TTE), and (2) whether E / E ′ contributed to BNP improvement independent of bodyweight reduction (UMIN000005565). Methods. Patients with type 2 diabetes and left ventricular ejection fraction LVEF ≥ 40 % without heart failure symptoms were enrolled, and daily injection with liraglutide (0.9 mg) was introduced. Cardiac functions were assessed by TTE before and after 26 weeks of liraglutide treatment. Diastolic cardiac function was defined as septal E / E ′ ≥ 13.0 . Results. Thirty-one patients were analyzed. BNP and E / E ′ improved, with BNP levels declining from 36.8 ± 30.5 pg / mL to 26.3 ± 25.9 pg / mL ( p = 0.0014 ) and E / E ′ dropping from 12.7 ± 4.7 to 11.0 ± 3.3 ( p = 0.0376 ). The LVEF showed no significant changes. E / E ′ improved only in patients with E / E ′ ≥ 13.0 . Favorable changes in E / E ′ were canceled when adjusted for body mass index (BMI). Multivariate linear regression analysis revealed that the left ventricular diastolic diameter and ∆ E / E ′ /∆BMI contributed to ∆BNP/baseline BNP ( p = 0.0075 , R 2 = 0.49264 ). Conclusions. Liraglutide had favorable effects on BNP and E / E ′ but not on LVEF. E / E ′ improvement was only seen in patients with diastolic cardiac function. Body weight reduction affected the change of E / E ′ . The BMI-adjusted E / E ′ significantly contributed to the relative change of BNP. GLP-1 analog treatment could be considered a therapeutic option against diabetic diastolic cardiac dysfunction regardless of body weight. This trial is registered with the University Hospital Medical Information Network in Japan, with clinical trial registration number: UMIN000005565.

A 6-month systems toxicology inhalation study in ApoE−/− mice demonstrates reduced cardiovascular effects of E-vapor aerosols compared with cigarette smoke

Analysis of key urinary oxidative stress markers and proinflammatory cytokines showed an absence of oxidative stress and inflammation in the animals exposed to E-vapor aerosols. Conversely, animals exposed to conventional cigarette smoke had high urinary levels of these markers. When compared with conventional cigarette smoke, E-vapor aerosols induced smaller atherosclerotic plaque surface area and volume. Systolic and diastolic cardiac function, as well as endothelial function, were further significantly less affected by electronic cigarette aerosols than conventional cigarette smoke. Molecular analysis demonstrated that E-vapor aerosols induce significantly smaller transcriptomic dysregulation in the heart and aorta compared with conventional cigarette smoke.

Thyroid replacement therapy effects on cardiac function in patients with hypothyroidism

Introduction/Objective. Hypothyroidism is a hypometabolic syndrome with insufficient production or inadequate action of thyroid hormones. It is characterized by hypercholesterolemia, elevated LDL-C. The most common echocardiographic changes are in left ventricular (LV) diastolic function. The aim of this study was to investigate the effects of achieving adequate thyroid hormone replacement therapy in hypothyroid patients on improving systolic and diastolic cardiac function and correcting serum lipid profile. Methods. Prospective study was conducted on 42 patients with newly diagnosed hypothyroidism, both sexes, aged 18-60 years, without comorbidity. The determined blood tests before, six, 12, and 24 weeks after starting the therapy with L-thyroxine were: FT4, TSH, total cholesterol, HDL-C, LDL-C and triglycerides. The effects of thyroid hormone replacement therapy on systolic and diastolic cardiac function were assessed by echocardiography. Results. 25 (59.5%) patients had subclinical and 17 (40.5%) overt hypothyroidism. The LV end-systolic diameter decreased statistically highly significant (p < 0.01) after 12 weeks and end-diastolic diameter of the right ventricle after six months of therapy. There was no significant decrease in LV end-diastolic diameter after six months of thyroid hormone replacement therapy. MAPSE, LVEF, and TAPSE values increased significantly (p < 0.01) after six weeks of therapy. Total cholesterol and LDL-C significantly decreased, HDL-C increased (p < 0.01) and there was no change in triglyceride concentrations after 24 weeks of therapy. Conclusions. . Thyroid replacement therapy in hypothyroid subjects statistically significantly improves echocardiographic parameters of diastolic and systolic left and right ventricular function, reduces total serum cholesterol and LDL-C, and increases HDL-C.

P196 Effect of tofogliflozin on systolic and diastolic cardiac function in type 2 diabetic patients

Funding Acknowledgements None Background Recent studies have shown that sodium glucose cotransporter 2 (SGLT2) inhibitors have a favorable effect on cardiovascular events in diabetic patients. However, the underlying mechanism associated with favorable outcome has not been clearly identified. Purpose The purpose of this study was to investigate the effect of tofogliflozin, SGLT2 inhibitor, on systolic and diastolic cardiac function in patients with type 2 diabetes mellitus (T2DM). Methods We enrolled 26 consecutive T2DM out-patients on glucose-lowering drugs who initiated tofogliflozin and underwent echocardiogram before and ≥ 6 months after tofogliflozin administration. During this period, we also enrolled 162 T2DM out-patients taking other glucose-lowering drugs as a control group. Propensity score analysis was performed to match the patient characteristics. As a result, 40 patients (tofogliflozin group: 20 patients and control group: 20 patients) were finally used for analysis. Left ventricular systolic function was assessed by measuring 2D-echocardiographic left ventricular ejection fraction (LVEF) and diastolic cardiac function by pulsed wave Doppler derived early diastolic velocity (E/e’). Results There were no significant differences in patient characteristics and echocardiographic parameters at baseline. Follow-up E/e’ was significantly improved in tofogliflozin compared to control (11.7 ± 3.5 vs. 14.4 ± 4.5, p = 0.037). Moreover, the change in LVEF from baseline to follow up was 5.8± 7.2% in tofogliflozin group and 1.2 ± 6.9% in control group; difference significant: p = 0.047. Conclusions In addition to conventional oral glucose-lowering drugs, additional tofogliflozin administration had a favorable effect on left ventricular systolic and diastolic function in patients with T2DM.