Diastolic left ventricular function in relation to the retinal microvascular fractal dimension in a Flemish population

Fractal analysis provides a global assessment of vascular networks (e.g., geometric complexity). We examined the association of diastolic left ventricular (LV) function with the retinal microvascular fractal dimension. A lower fractal dimension signifies a sparser retinal microvascular network. In 628 randomly recruited Flemish individuals (51.3% women; mean age, 50.8 years), we measured diastolic LV function by echocardiography and the retinal microvascular fractal dimension by the box-counting method (Singapore I Vessel Assessment software, version 3.6). The left atrial volume index (LAVI), e′, E/e′ and retinal microvascular fractal dimension averaged (±SD) 24.3 ± 6.2 mL/m2, 10.9 ± 3.6 cm/s, 6.96 ± 2.2, and 1.39 ± 0.05, respectively. The LAVI, E, e′ and E/e′ were associated (P < 0.001) with the retinal microvascular fractal dimension with association sizes (per 1 SD), amounting to −1.49 mL/m2 (95% confidence interval, −1.98 to −1.01), 2.57 cm/s (1.31–3.84), 1.34 cm/s (1.07–1.60), and −0.74 (−0.91 to −0.57), respectively. With adjustments applied for potential covariables, the associations of E peak and E/e′ with the retinal microvascular fractal dimension remained significant (P ≤ 0.020). Over a median follow-up of 5.3 years, 18 deaths occurred. The crude and adjusted hazard ratios expressing the risk of all-cause mortality associated with a 1-SD increment in the retinal microvascular fractal dimension were 0.36 (0.23–0.57; P < 0.001) and 0.57 (0.34–0.96; P = 0.035), respectively. In the general population, a lower retinal microvascular fractal dimension was associated with greater E/e′, a measure of LV filling pressure. These observations can potentially be translated into new strategies for the prevention of diastolic LV dysfunction.

The role of thyrostatic agents in the treatment of chronic heart failure patients with comorbid coronary artery disease and thyrotoxicosis

Background: Thyroid dysfunction exerts a pronounced effect on the cardiovascular system, and, if comorbid with an existing cardiovascular disorder, may lead to a significant deterioration in the outcome, thus obviating the need for timely diagnosis and therapy optimization.Aim: To evaluate the effect of combination therapy, including thyrostatics, on the clinical symptoms of chronic heart failure (CHF), heart rate variability, NT-proBNP concentration, and structural and functional parameters of the left heart in patients with comorbid coronary artery disease (CAD) and thyrotoxicosis.Materials and methods: This open-label comparative study included 77 patients aged 45–65 years. The study group consisted of 36 patients with thyrotoxicosis, CAD and CHF II–III functional class, whereas the comparison group consisted of 41 patients with thyrotoxicosis without cardiovascular diseases. The patients were assessed clinically at baseline and after 6 months of therapy with addition of a thyrostatic, with tolerance to physical activity, measurements of NT-proBNP levels, 24-hour Holter monitoring, and echocardiography.Results: At 6 months of the combination therapy including a thyrostatic, with stable drug-induced euthyroidism, the patients in the group 1 showed an increase in the distance of a 6-minute walking test (p<0.001) and a decrease in CHF clinical symptoms. The incidence of heart rhythm disorders decreased (supraventricular extra systoles from 31% to 16%, ventricular extra systoles from 21% to 4%, atrial fibrillation from 32% to 23%; p<0.05), with a positive trend for spectral and temporal parameters of heart rate variability. The NT-proBNP level in patients with CAD, CHF and thyrotoxicosis decreased by 42.9% (p=0.001). During euthyrosis, echocardiography in the patients with ischemic CHF and concomitant thyrotoxicosis showed a significant increase in stroke volume (p=0.03), stroke ejection index (p=0.04), left ventricular ejection fraction (p=0.01), a decrease in the value of myocardial stress (p=0.02), and transmitral blood flow parameters (E/A, p<0.05). This indicates an improvement in systolic and diastolic left ventricular function after normalization of thyroid function.Conclusion: The inclusion of thyreostatics to the combination therapy and the achievement of euthyrosis have contributed to increased tolerance to physical activity, reduction of sympathetic activity level of the autonomic nervous system and frequency of heart rhythm disorders, reduced the NT-proBNP levels, improved systolic and diastolic left ventricular function in patients with ischemic CHF and concomitant thyrotoxicosis.

Diastolic left ventricular function in relation to circulating metabolic biomarkers in a population study

Aims We studied the association of circulating metabolic biomarkers with asymptomatic left ventricular diastolic dysfunction, a risk-carrying condition that affects 25% of the population. Methods and results In 570 randomly recruited people, we assessed in 2005–2010 and in 2009–2013 the multivariable-adjusted correlations of e’ (early left ventricular relaxation) and E/e’ (left ventricular filling pressure) measured by Doppler echocardiography with 43 serum metabolites, quantified by magnetic resonance spectroscopy. In 2009–2013, e’ cross-sectionally increased (Bonferroni corrected p ≤ 0.016) with the branched-chain amino acid valine (per one standard deviation increment, +0.274 cm/s (95% confidence interval, 0.057–0.491)) and glucose+the amino acid (AA) taurine (+0.258 cm/s (0.067–0.481)), while E/e’ decreased ( p ≤ 0.017) with valine (–0.264 (–0.496– –0.031)). The risk of developing left ventricular diastolic dysfunction over follow-up (9.4%) was inversely associated ( p ≤ 0.0059) with baseline glucose+amino acid taurine (odds ratio, 0.64 (0.44–0.94). In partial least squares analyses of all the baseline and follow-up data, markers consistently associated with better diastolic left ventricular function included the amino acids 2-aminobutyrate and 4-hydroxybutyrate and the branched-chain amino acids leucine and valine, and those consistently associated with worse diastolic left ventricular function glucose+amino acid glutamine and fatty acid pentanoate. Branched-chain amino acid metabolism (–log10 p = 12.6) and aminoacyl-tRNA biosynthesis (9.9) were among the top metabolic pathways associated with left ventricular diastolic dysfunction. Conclusion The associations of left ventricular diastolic dysfunction with circulating amino acids and branched-chain amino acids were consistent over a five-year interval and suggested a key role of branched-chain amino acid metabolism and aminoacyl-tRNA biosynthesis in maintaining diastolic left ventricular function.