Echocardiographic Parameters as Predictors for the Efficiency of Resynchronization Therapy in Patients with Dilated Cardiomyopathy and HFrEF

Cardiac resynchronization therapy (CRT) represents an increasingly recommended solution to alleviate symptomatology and improve the quality of life in individuals with dilated cardiomyopathy (DCM) and heart failure (HF) with reduced ejection fraction (HFrEF) who remain symptomatic despite optimal medical therapy (OMT). However, this therapy does have the desired results all cases, in that sometimes low sensing and high voltage stimulation are needed to obtain some degree of resynchronization, even in the case of perfectly placed cardiac pacing leads. Our study aims to identify whether there is a relationship between several transthoracic echocardiographic (TTE) parameters characterizing left ventricular (LV) performance, especially strain results, and sensing and pacing parameters. Between 2020–2021, CRT was performed to treat persistent symptoms in 48 patients with a mean age of 64 (53.25–70) years, who were diagnosed with DCM and HFrEF, and who were still symptomatic despite OMT. We documented statistically significant correlations between global longitudinal strain, posterolateral strain, and ejection fraction and LV sensing (r = 0.65, 0.469, and 0.534, respectively, p < 0.001) and LV pacing parameters (r = −0.567, −0.555, and −0.363, respectively, p < 0.001). Modern imaging techniques, such as TTE with cardiac strain, are contributing to the evaluation of patients with HFrEF, increasing the chances of CRT success, and allowing physicians to anticipate and plan for case management.

Marathon-Induced Cardiac Strain as Model for the Evaluation of Diagnostic microRNAs for Acute Myocardial Infarction

Background: The current gold standard biomarker for myocardial infarction (MI), cardiac troponin (cTn), is recognized for its high sensitivity and organ specificity; however, it lacks diagnostic specificity. Numerous studies have introduced circulating microRNAs as potential biomarkers for MI. This study investigates the MI-specificity of these serum microRNAs by investigating myocardial stress/injury due to strenuous exercise. Methods: MicroRNA biomarkers were retrieved by comprehensive review of 109 publications on diagnostic serum microRNAs for MI. MicroRNA levels were first measured by next-generation sequencing in pooled sera from runners (n = 46) before and after conducting a full competitive marathon. Hereafter, reverse transcription quantitative real-time PCR (qPCR) of 10 selected serum microRNAs in 210 marathon runners was performed (>10,000 qPCR measurements). Results: 27 potential diagnostic microRNA for MI were retrieved by the literature review. Eight microRNAs (miR-1-3p, miR-21-5p, miR-26a-5p, miR-122-5p, miR-133a-3p, miR-142-5p, miR-191-5p, miR-486-3p) showed positive correlations with cTnT in marathon runners, whereas two miRNAs (miR-134-5p and miR-499a-5p) showed no correlations. Upregulation of miR-133a-3p (p = 0.03) and miR-142-5p (p = 0.01) went along with elevated cTnT after marathon. Conclusion: Some MI-associated microRNAs (e.g., miR-133a-3p and miR-142-5p) have similar kinetics under strenuous exercise and MI as compared to cTnT, which suggests that their diagnostic specificity could be limited. In contrast, several MI-associated microRNAs (miR-26a-5p, miR-134-5p, miR-191-5p) showed different release behavior; hence, combining cTnT with these microRNAs within a multi-marker strategy may add diagnostic accuracy in MI.

Global Longitudinal Myocardial Strain Correlates with Degree of Anemia in Sickle Cell Disease but Not Transfusion-Dependent Thalassemia

Cardiac failure is one of the leading causes of death in sickle cell disease (SCD) and transfusion-dependent thalassemia (TDT). For this reason, early detection of silent cardiac dysfunction is crucial for treatment and prevention of heart failure. Speckle-tracking echocardiography (STE) is an easily accessible tool for analyzing myocardial function and this modality has increased sensitivity in detecting asymptomatic disease. Attenuation in cardiac strain has been correlated to early systolic dysfunction among patients with cardiomyopathies. This technique has not been consistently evaluated in children with SCD and TDT. Due to the role of anemia and siderosis in the pathology of cardiac dysfunction, we hypothesized that early myocardial dysfunction correlates with the degree of anemia and hyperferritinemia in SCD. We analyzed the clinical, echocardiographic, STE and laboratory parameters in SCD and compared them to children with TDT and normal controls. We retrospectively analyzed date from consecutive patients with SCD and TDT who received treatment at our institution from 2008 to 2018. Echocardiographic data from children with benign murmurs served as normal controls (NC). Data was independently verified by a pediatric cardiologist. Descriptive and correlation analysis were used; a p-value &lt; 0.05 was considered significant. Echocardiographic data were available for 77 SCD (HbSS and HbS/ ß 0 Thal), 25 TDT (ß 0/ ß 0 and ß +/ ß + Thal)and 138 NC. Mean hemoglobin (Hg) and ferritin values were 9.8 g/dl (6.8-14.6 g/dl); 392 ng/ml (19.3-8,3437.67 ng/ml), respectively for SCD patients and 9.3 g/dl (7-17.03 ng/dl); 2,960 ng/ml (13-13,831 ng/ml), respectively for TDT. Standard echocardiographic parameters left ventricular ejection fraction (LVEF), right VEF and LV shortening fraction (LVSF) were within the normal limits in SCD, TDT, and NC children. Significant differences were observed in the steady-state global circumferential strain (GCS) between the three groups SCD, TDT and NC [-26.5 (mean), 3.6 (SD); -27.6 (mean), 4.8(SD); -25.0 (mean), 3.6 (SD), respectively; p = 0.002] (Table 1). Subset analysis based on ferritin levels (&gt; or &lt; 1000 ng/ml), revealed no significant difference in GCS between the SCD or TDT groups (Table 2). However, global longitudinal strain (GLS) was significantly lower among SCD compared to TDT with ferritin levels greater than 1,000 ng/ml (Table 2). A positive correlation (r = 0.25, p = 0.046) was found between GLS and Hg in SCD patients (n=63) (Figure 1). No significant correlation was found between Hg and GLS in the TDT group (Figure 2). No significant correlation was found between GCS and Hg (r = 0.1, p = 0.42); GLS and GCS and ferritin in the SCD group. LVEF was found to be normal in patients with abnormal strain indices. Cardiac strain indices are abnormal in children with SCD and TDT compared to normal children. Significantly abnormal GLS was noted in hyperferritinemic SCD patients compared to TDT patients. A positive correlation between severity of anemia and GLS was observed in this study in SCD children. Based on these results, we speculate that therapies aimed at ameliorating anemia can potentially improve GLS and thus, early cardiac dysfunction in SCD patients. However, further studies are warranted to understand the contributory role of anemia and hyperferritinemia and its therapeutic implications on early myocardial dysfunction in SCD. Figure 1 Figure 1. Disclosures Sathi: Vertex Pharmaceuticals: Consultancy.

Left-Ventricular Reference Myocardial Strain Assessed by Cardiovascular Magnetic Resonance Feature Tracking and fSENC—Impact of Temporal Resolution and Cardiac Muscle Mass

Aims: Cardiac strain parameters are increasingly measured to overcome shortcomings of ejection fraction. For broad clinical use, this study provides reference values for the two strain assessment methods feature tracking (FT) and fast strain-encoded (fSENC) cardiovascular magnetic resonance (CMR) imaging, including the child/adolescent group and systematically evaluates the influence of temporal resolution and muscle mass on strain.Methods and Results: Global longitudinal (GLS), circumferential (GCS), and radial (GRS) strain values in 181 participants (54% women, 11–70 years) without cardiac illness were assessed with FT (CVI42® software). GLS and GCS were also analyzed using fSENC (MyoStrain® software) in a subgroup of 84 participants (60% women). Fourteen patients suffering hypertrophic cardiomyopathy (HCM) were examined with both techniques. CMR examinations were done on a 3.0T MR-system.FT-GLS, FT-GCS, and FT-GRS were −16.9 ± 1.8%, −19.2 ± 2.1% and 34.2 ± 6.1%. fSENC-GLS was higher at −20.3 ± 1.8% (p &lt; 0.001). fSENC-GCS was comparable at−19.7 ± 1.8% (p = 0.06). All values were lower in men (p &lt; 0.001). Cardiac muscle mass correlated (p &lt; 0.001) with FT-GLS (r = 0.433), FT-GCS (r = 0.483) as well as FT-GRS (r = −0.464) and acts as partial mediator for sex differences. FT-GCS, FT-GRS and fSENC-GLS correlated weakly with age. FT strain values were significantly lower at lower cine temporal resolutions, represented by heart rates (r = −0.301, −0.379, 0.385) and 28 or 45 cardiac phases per cardiac cycle (0.3–1.9% differences). All values were lower in HCM patients than in matched controls (p &lt; 0.01). Cut-off values were −15.0% (FT-GLS), −19.3% (FT-GCS), 32.7% (FT-GRS), −17.2% (fSENC-GLS), and −17.7% (fSENC-GCS).Conclusion: The analysis of reference values highlights the influence of gender, temporal resolution, cardiac muscle mass and age on myocardial strain values.

Diabetes status-related differences in risk factors and mediators of heart failure in the general population: results from the MORGAM/BiomarCaRE consortium

Background The risk of heart failure among diabetic individuals is high, even under tight glycemic control. The correlates and mediators of heart failure risk in individuals with diabetes need more elucidation in large population-based cohorts with long follow-up times and a wide panel of biologically relevant biomarkers. Methods In a population-based sample of 3834 diabetic and 90,177 non-diabetic individuals, proportional hazards models and mediation analysis were used to assess the relation of conventional heart failure risk factors and biomarkers with incident heart failure. Results Over a median follow-up of 13.8 years, a total of 652 (17.0%) and 5524 (6.1%) cases of incident heart failure were observed in participants with and without diabetes, respectively. 51.4% were women and the mean age at baseline was 48.7 (standard deviation [SD] 12.5) years. The multivariable-adjusted hazard ratio (HR) for heart failure among diabetic individuals was 2.70 (95% confidence interval, 2.49–2.93) compared to non-diabetic participants. In the multivariable-adjusted Cox models, conventional cardiovascular disease risk factors, such as smoking (diabetes: HR 2.07 [1.59–2.69]; non-diabetes: HR 1.85 [1.68–2.02]), BMI (diabetes: HR 1.30 [1.18–1.42]; non-diabetes: HR 1.40 [1.35–1.47]), baseline myocardial infarction (diabetes: HR 2.06 [1.55–2.75]; non-diabetes: HR 2.86 [2.50–3.28]), and baseline atrial fibrillation (diabetes: HR 1.51 [0.82–2.80]; non-diabetes: HR 2.97 [2.21–4.00]) had the strongest associations with incident heart failure. In addition, biomarkers for cardiac strain (represented by nT-proBNP, diabetes: HR 1.26 [1.19–1.34]; non-diabetes: HR 1.43 [1.39–1.47]), myocardial injury (hs-TnI, diabetes: HR 1.10 [1.04–1.16]; non-diabetes: HR 1.13 [1.10–1.16]), and inflammation (hs-CRP, diabetes: HR 1.13 [1.03–1.24]; non-diabetes: HR 1.29 [1.25–1.34]) were also associated with incident heart failure. In general, all these associations were equally strong in non-diabetic and diabetic individuals. However, the strongest mediators of heart failure in diabetes were the direct effect of diabetes status itself (relative effect share 43.1% [33.9–52.3] and indirect effects (effect share 56.9% [47.7-66.1]) mediated by obesity (BMI, 13.2% [10.3–16.2]), cardiac strain/volume overload (nT-proBNP, 8.4% [-0.7–17.4]), and hyperglycemia (glucose, 12.0% [4.2–19.9]). Conclusions The findings suggest that the main mediators of heart failure in diabetes are obesity, hyperglycemia, and cardiac strain/volume overload. Conventional cardiovascular risk factors are strongly related to incident heart failure, but these associations are not stronger in diabetic than in non-diabetic individuals. Active measurement of relevant biomarkers could potentially be used to improve prevention and prediction of heart failure in high-risk diabetic patients.

Sex differences in the physiological responses to exercise-induced dehydration: Consequences and mechanisms?

Physiological strain during exercise is increased by mild dehydration (~1-3% body mass loss). This response may be sex-dependent but there are no direct comparative data in this regard. This review aimed to develop a framework for future research by exploring the potential impact of sex on thermoregulatory and cardiac strain associated with exercise-induced dehydration. Sex-based comparisons were achieved by comparing trends from studies that implemented similar experimental protocols but recruited males and females separately. This revealed a higher core temperature (Tc) in response to exercise-induced dehydration in both sexes, however it seemingly occurred at a lower percent body mass loss in females. Although less clear, similar trends existed for cardiac strain. The average female may have a lower body water volume per body mass compared to males, and therefore the same % body mass loss between the sexes may represent a larger portion of total body water in females potentially posing a greater physiological strain. Additionally, the rate which Tc increases at exercise onset might be faster in females and induce a greater thermoregulatory challenge earlier into exercise. The Tc response at exercise onset is associated with lower sweating rates in females, which is commonly attributed to sex-differences in metabolic heat production. However, a reduced sweat gland sensitivity to stimuli, lower fluid output per sweat gland, and sex hormones promoting fluid retention in females may also contribute. In conclusion, the limited evidence suggests sex-based differences exist in thermoregulatory and cardiac strain associated with exercise-induced dehydration, and this warrants future investigations.

Cytoprotective effects of spirulina extract against doxorubicin‐induced cardiotoxicity: Biochemical evidences and translational perspectives in cardio-oncology.

e15042 Background: Spirulina, a blue-green algae used in the daily diet of natives of Africa and America, has antioxidant, anticancer, antiviral, hepatoprotective, immune enhancing and lipid-lowering effects. Considering that doxorubicin-induced cardiotoxicity involves myocardial inflammation, ferroptosis and overexpression of several cytokines involved in cell dead and apoptosis, the use of spirulina during exposure to doxorubicin could be an intriguing method to reduces myocardial injuries in cancer patients undergoing treatment with anthracyclines. Methods: Human fetal cardiomyocytes (HFC cell line) were exposed to doxorubicin (from 10 to 500 nM), alone or in combination with spirulina extract (from 10 to 100 µg/ml) for 24 and 48h. After the incubation period, we performed the following tests: determination of cell viability, through analysis of mitochondrial dehydrogenase activity, study of lipid peroxidation (quantifying cellular Malondialdehyde and 4-hydroxynonenal), intracellular Ca2+ homeostasis. Moreover, pro-inflammatory studied were also performed (activation of NLRP3 inflammasome; expression of TLR4/MyD88; mTORC1 Fox01/3a; transcriptional activation of p65/NF-κB and secretion of cytokines involved in cardiotoxicity (Interleukins 1β, 8, 6). Results: Spirulina extract, co-incubated with doxorubicin exerts cardioprotective effects, enhancing cell viability of 20-36.7 % compared to untreated cells (p<0,01 for all); spirulina extract reduced significantly the cardiotoxicity through MyD88/NF-KB/cytokines axis and mTORC1 Fox01/3α mediated mechanisms and reduces oxidative damages of doxorubicin resulting in lower intracellular calcium content. Conclusions: For the first time, it was demonstrated that spirulina extract exert anti-inflammatory and cytoprotective properties in myocardial cells exposed to growing concentration of doxorubicin leading to preclinical studies in mice analyzing any effects on cardiac strain and left ventricular ejection function.

Pregnancy-specific reference intervals for BNP and NT-pro BNP – changes in natriuretic peptides related to pregnancy

Background Cardiac disease is the leading cause of maternal mortality in the UK, so accurate cardiovascular diagnoses in pregnancy are essential. BNP (B-type natriuretic peptide) and NT-pro BNP (N-terminal-pro BNP) are useful clinical tools for investigating suspected peripartum cardiomyopathy but, as the pregnancy-specific reference intervals are undefined, it is uncertain how they should be interpreted in pregnant women. Methods Longitudinal study of 260 healthy pregnant women, with sampling in each trimester to define 95% reference intervals. Results The upper reference limit for NT-pro BNP was 200 pg/mL in the first and second trimesters, and 150 pg/mL in the third. Levels were significantly reduced in overweight women in the third trimester (p=0.0001), which supports the partitioning of reference intervals by BMI. The upper limit for BNP was 50 pg/mL, with no detectable trimester-related differences. Whilst other biomarkers (haemoglobin and platelets) fell throughout pregnancy, both natriuretic peptides were initially elevated before falling by the third trimester, suggesting that the observed changes in natriuretic peptides are driven by dynamic interplay between cardiac strain and progressive haemodilution. NT-pro BNP in the first trimester was inversely associated with neonatal birthweight at term (p=0.011). Conclusions Cardiac biomarkers have an important role for investigating suspected disease in high-risk pregnant women, but a robust assessment of the levels expected in healthy pregnant women is an essential prerequisite to their application in clinical practice. This study has defined trimester- and BMI-specific reference intervals for NT-pro BNP and BNP, which may improve how women with suspected cardiovascular disease are investigated in pregnancy.