Correlation between extent of myocardial fibrosis assessed by cardiac magnetic resonance and cardiac troponin T release in patients with nonischemic heart failure

Associations Between Biomarkers of Myocardial Injury and Systemic Inflammation and Risk of Incident Ventricular Arrhythmia

BACKGROUND

Cardiac troponins (cTns) and biomarkers of inflammation are elevated in heart failure (HF) and predict cardiovascular risk. Whether these biomarkers associate with risk of ventricular arrhythmias (VAs) is unclear.

OBJECTIVES

This study sought to assess whether cTnT, growth differentiation factor 15 (GDF-15), interleukin-6 (IL-6), and C-reactive protein (CRP) concentrations are associated with incident VA.

METHODS

In a prospective, observational study of patients treated with implantable cardioverter-defibrillator, cTnT, GDF-15, IL-6, and CRP were measured at baseline and after 1.4 ± 0.5 years and were associated with implantable cardioverter-defibrillator-detected incident VA, HF hospitalizations, and mortality.

RESULTS

This study included 489 patients aged 66 ± 12 years and 83% were men. Median concentrations of cTnT were 15 (Q1-Q3: 9-25) ng/L at inclusion, and higher concentrations were associated with higher age, male sex, diabetes mellitus, coronary artery disease, and HF. During 3.1 ± 0.7 years of follow-up, 137 patients (28%) had ≥1 VA. cTnT concentrations were associated with an increased VA risk (per log-unit, HR: 1.63; 95% CI: 1.31-2.01; P < 0.001), also after adjustment for age, sex, body mass index, coronary artery disease, HF, renal function, and left ventricular ejection fraction (P < 0.001). GDF-15, IL-6, and CRP concentrations were not associated with incident VA, but all (including cTnT) were associated with HF hospitalization and mortality. Changes in cTnT, GDF-15, IL-6, and CRP from baseline to 1.4 years were not associated with subsequent VA.

CONCLUSIONS

Higher concentrations of cTnT, GDF-15, IL-6, and CRP associate with HF hospitalization and death, but only cTnT predict incident VA. These findings suggest that myocardial injury rather than inflammation may play a pathophysiological role in VA and sudden cardiac death.

CARDIOTOXICITY IN BREAST CANCER PATIENTS: RELATIONSHIP OF HS-TROPONIN T CHANGES AND HEART FUNCTION IN CANCER TREATMENT

Breast cancer patients (BC) have a high risk of cardiotoxicity (CT) due to a combination of cancer treatments.Cardiovascular (CV) complications lead to delay or withdrawal of BC therapy and worsen the survival. Therefore, it isimportant to detect CT at the early stages before the occurrence of cardiac dysfunction and heart failure (HF) signs.

OBJECTIVE

to study the dynamic changes of high-sensitivity (hs) troponin (Tn) T (hs-TnT) level in BC patients during cancer treatment with the use of chemotherapy and radiation therapy (RT) to predict and prevent CV complications during individualized management.

MATERIAL AND METHODS

40 BC patients were included in the pilot study. The analysis of the dynamic changes of hs-TnT and ejection fraction (EF) of the left ventricle (LV) was performed before and within 6 months of cancer treatment. Based on the data analysis, a definition of a significant increase in hs-TnT was developed and proposed. Therise of hs-TnT was calculated by the difference (%) between its baseline level and in the 6 months of cancer treatment. BC patients are grouped into tertiles according to the hs-TnT increase: group 1 - low level (0-50 %), group 2 -moderate level (> 50-100 %), and group 3 - high level (> 100 %).

RESULTS

Before the start of cancer treatment, LVEF did not differ significantly between groups (mean EF (62.6 ± 1.0) %)and the hs-TnT level was also within normal values (0.008±0.001 ng/ml). In 6 months of cancer treatment, LVEF waswithin the normal ranges and did not differ significantly in patients of group 1. However, in patients of groups 2and 3 - LVEF drop (δLV EF) was 5.7 % (р < 0.01) and 10.8 % (р < 0.01), consequently. According to the correlationanalysis, the percentage of increase in hs-TnT (δhs-TnT) was associated with δEF LV (r = 0.39, р < 0.05) and the useof anthracyclines (AC) (r = 0.37, р < 0.05). Using logistic regression and ROC analysis, the diagnostic threshold valueof the hs-TnT increase > 165 % was defined, which can be considered as a reliable marker of early biochemical CT,with a sensitivity of 99 % and a specificity of 56 %.

CONCLUSIONS

In BC patients, based on the level of hs-TnT increase, proposed a new early biochemical CT detectionmethod. Under the new approach, BC patients with hsTnT increase of > 165 % from baseline can be considered as areliable marker of early biochemical CT, with a sensitivity of 99 % and a specificity of 56 %.

Serum Galectin-3 and Aldosterone: potential biomarkers of cardiac complications in patients with COVID-19

BACKGROUND

Despite severe acute respiratory syndrome (SARS)-Coronavirus (CoV2) primarily targeting the lungs, the heart represents another critical virus target. Thus, the identification of SARS-CoV-2 disease of 2019 (COVID-19)-associated biomarkers would be beneficial to stratify prognosis and the risk of developing cardiac complications. Aldosterone and galectin-3 promote fibrosis and inflammation and are considered a prognostic biomarker of lung and adverse cardiac remodeling. Here, we tested whether galectin-3 and aldosterone levels can predict adverse cardiac outcomes in COVID-19 patients.

METHODS

To this aim, we assessed galectin-3 and aldosterone serum levels in 51 patients diagnosed with COVID-19, using a population of 19 healthy subjects as controls. In in vitro studies, we employed 3T3 fibroblasts to assess the potential roles of aldosterone and galectin-3 in fibroblast activation.

RESULTS

Serum galectin-3 levels were more elevated in COVID-19 patients than healthy controls and correlated with COVID-19 severity classification and cardiac Troponin-I (cTnI) serum levels. Furthermore, we observed an augmented secretion of aldosterone in COVID-19 patients. This adrenal hormone is a direct stimulator of galectin-3 secretion; therefore, we surmised that this axis could perpetrate fibrosis and adverse remodeling in these subjects. Thus, we stimulated fibroblasts with 10% of serum from COVID-19 patients. This challenge markedly rose the expression of smooth muscle alpha (α)-2 actin (ACTA2), a myofibroblast marker.

CONCLUSIONS

Our study suggests that COVID-19 can affect cardiac structure and function by triggering aldosterone and galectin-3 release that may serve as prognostic and therapeutic biomarkers while monitoring the course of cardiac complications in patients suffering from COVID-19.

Identification of Functional Genetic Determinants of Cardiac Troponin T and I in a Multiethnic Population and Causal Associations With Atrial Fibrillation

BACKGROUND

Elevated cardiac troponin levels in blood are associated with increased risk of cardiovascular diseases and mortality. Cardiac troponin levels are heritable, but their genetic architecture remains elusive.

METHODS

We conducted a transethnic genome-wide association analysis on high-sensitivity cTnT (cardiac troponin T; hs-cTnT) and high-sensitivity cTnI (cardiac troponin I; hs-cTnI) levels in 24 617 and 14 336 participants free of coronary heart disease and heart failure from 6 population-based cohorts, followed by a series of bioinformatic analyses to decipher the genetic architecture of hs-cTnT and hs-cTnI.

RESULTS

We identified 4 genome-wide significant loci for hs-cTnT including a novel locus rs3737882 in PPFIA4 and 3 previously reported loci at NCOA2, TRAM1, and BCL2. One known locus at VCL was replicated for hs-cTnI. One copy of C allele for rs3737882 was associated with a 6% increase in hs-cTnT levels (minor allele frequency, 0.18; P=2.80×10-9). We observed pleiotropic loci located at BAG3 and ANO5. The proportions of variances explained by single-nucleotide polymorphisms were 10.15% and 7.74% for hs-cTnT and hs-cTnI, respectively. Single-nucleotide polymorphisms were colocalized with BCL2 expression in heart tissues and hs-cTnT and with ANO5 expression in artery, heart tissues, and whole blood and both troponins. Mendelian randomization analyses showed that genetically increased hs-cTnT and hs-cTnI levels were associated with higher odds of atrial fibrillation (odds ratio, 1.38 [95% CI, 1.25-1.54] for hs-cTnT and 1.21 [95% CI, 1.06-1.37] for hs-cTnI).

CONCLUSIONS

We identified a novel genetic locus associated with hs-cTnT in a multiethnic population and found that genetically regulated troponin levels were associated with atrial fibrillation.

Proteomic Biomarkers in the Cardiorenal Syndrome: Toward Deciphering Molecular Pathophysiology

Cardiorenal syndrome (CRS) is defined by coexisting heart and renal dysfunctions. Malfunction of 1 organ may cause dysfunction of the other with variable causative disease that defines the type of CRS (1-5). Numerous studies showed that the prevalence of cardiovascular disease is increased in patients with chronic kidney disease (CKD). Similarly, CKD affects a large proportion of patients with heart failure. This overlap between primary heart or primary kidney disease blurs cause-effect inferences of the initiator/target organ. The classical subdivision of CRS in 5 categories does not provide pathophysiological suggestions for targeted intervention. It seems timely to revisit the value of CRS biomarkers in a pathophysiology-centered approach. We systematically reviewed the literature in CRS, which revealed 53 clinical studies describing the use of 44 biomarkers and 4 proteomic panels. All biomarkers are involved in at least one of the CRS comorbidities. Among the pathways affected, inflammation, aberrant glucose metabolism, neurohormonal activation, and oxidative stress are well described. There is growing evidence that fibrosis may be the "cornerstone" that unifies most of the pathways leading to CRS. Formation of excess fibrous connective tissue antedates CRS in many cases. This review highlights that biomarkers reflecting fibrosis may be of substantial clinical value in the early detection, prognostication, and guiding treatment of CRS. Biomarkers detecting changes in collagen turnover in the extracellular matrix of heart and kidney appear able to depict subclinical changes in the fibrotic remodeling of tissues and constitute a promising approach toward personalized intervention in CRS.

Transmethylamine-N-Oxide Is Associated With Diffuse Cardiac Fibrosis in People Living With HIV

Background People living with HIV are at increased risk of developing diastolic dysfunction, heart failure, and sudden cardiac death, all of which have been characterized by higher levels of myocardial fibrosis. Transmethylamine-N-oxide (TMAO), a dietary gut metabolite, is linked to the development of myocardial fibrosis in animal models. However, it is unclear whether TMAO plays a role in the development of myocardial fibrosis in people living with HIV. Methods and Results The study population consisted of participants enrolled in the multisite cross-sectional study called CHART-HIV (Characterizing Heart Function on Anti-Retroviral Therapy). Participants underwent echocardiography, cardiac magnetic resonance imaging, biomarker analysis, and targeted assessment of gut-related circulating metabolites; diastolic dysfunction was determined by study-specific criteria. Multivariable linear regression models were performed to examine the relationship of gut-related metabolites with serum and imaging measures of myocardial fibrosis. Models were adjusted for traditional cardiovascular, inflammatory, and HIV-related risk factors. Diastolic dysfunction was present in 94 of 195 individuals (48%) in CHART-HIV; this cohort demonstrated higher prevalence of hypertension, hyperlipidemia, and chronic kidney disease as well as higher plasma levels of both TMAO and choline. TMAO levels were associated with parameters reflecting increased left ventricular filling pressures and with a marker of the innate immune system. TMAO levels correlated with diffuse myocardial fibrosis (R=0.35; P<0.05) as characterized by myocardial extracellular volume fraction as well as biomarkers reflective of myocardial fibrosis. Conclusions In this study of people living with HIV, the gut metabolite TMAO was associated with underlying diffuse myocardial fibrosis and found to be a potential marker of early structural heart disease. The mechanistic role of the gut microbiome in HIV-associated cardiovascular disease warrants further investigation. Registration URL: https://clinicaltrials.gov; Unique identifier: NCT02860156.

Molecular remodeling of Cx43, but not structural remodeling, promotes arrhythmias in an arrhythmogenic canine model of nonischemic heart failure

BACKGROUND

Both gap junctional remodeling and interstitial fibrosis have been linked to impaired electrical conduction velocity (CV) and fatal ventricular arrhythmias in nonischemic heart failure (HF). However, the arrhythmogenic role of the ventricular gap junctional Cx43 in nonischemic HF remains in debate. Here, we assessed this in a newly developed arrhythmogenic canine model of nonischemic HF.

METHODS AND RESULTS

Nonischemic HF was induced in canines by combined aortic valve insufficiency and aortic constriction. Left ventricular (LV) myocardium from HF dogs showed similar pathological changes to that of humans. HF dogs had reduced LV function, widened QRS complexes, and spontaneous nonsustained ventricular tachycardia. CV was measured in intact LV epicardium with high-density grid mapping. Total (Cx43-T) and nonphosphorylated Cx43 (Cx43-NP) and histological interstitial fibrosis were assessed from these mapped LV tissues. Longitudinal CV, which was slowed in HF (49 ± 1 vs. 65 ± 2 cm/s in Ctl), was positively correlated with reduced total junctional Cx43 and negatively correlated with markedly increased junctional Cx43-NP (2-fold) in HF. Cx43 dephosphorylation in HF was associated with enhanced colocalization of PP2A at the level of Cx43. Unchanged action potential upstroke and transverse CV were associated with unaltered Cx43 lateralization and interstitial fibrosis in the nonischemic HF canine LV.

CONCLUSION

Our unique arrhythmogenic canine model of HF resembles human nonischemic HF (prior to the end stage). Cx43 remodeling occurs prior to the structural remodeling (with lack of fibrosis) in HF and it is crucial in slowed CV and ventricular arrhythmia development. Our findings suggest that altered Cx43 alone is arrhythmogenic and modulation of Cx43 has the anti-arrhythmic therapeutic potential for HF patients.

The prognostic role of high-sensitivity cardiac troponin T over time in ischemic and non-ischemic heart failure

INTRODUCTION

High-sensitivity cardiac troponin T (hs-cTnT) as a prognostic biomarker can be detected in patients with heart failure (HF).

AIM

This study focuses on hs-cTnT to evaluate its prognostic role in ischemic heart failure (IHF) and non-ischemic heart failure (NIHF).

MATERIAL AND METHODS

One hundred and sixty patients with HF were divided into IHF and NIHF groups. Hs-cTnT measured at baseline, 2-5 h, 6-24 h and 24 h-7 d after admission was analyzed by generalized estimating equations. Patients were followed up for 1 year at the endpoint events of re-hospitalization for HF and all-cause death that was tested by the Kaplan-Meier method and the Cox regression method.

RESULTS

Hs-cTnT varied significantly over time, first increasing and then decreasing in IHF while showing a continuously elevated trend in NIHF. Patients with hs-cTnT levels > 0.014 ng/ml had a significantly higher re-hospitalization rate compared with those with hs-cTnT levels ≤ 0.014 ng/ml (23.7% vs. 7.0%, p < 0.05). Adjusted for age, New York Heart Association class, N-terminal pro-B-type natriuretic peptide, and left ventricular ejection fraction, baseline hs-cTnT was independently associated with re-hospitalization and all-cause death in HF (p < 0.05). Optimal hs-cTnT cut-off of 0.0275 ng/ml was derived to predict the re-hospitalization and death in IHF (AUC = 0.709, 95% CI: 0.561-0.856, sensitivity: 76.9%, specificity: 63.5%, p < 0.05).

CONCLUSIONS

Hs-cTnT varying over time is an important risk factor for the prognosis of patients with IHF and NIHF.

Why does Russia have such high cardiovascular mortality rates? Comparisons of blood-based biomarkers with Norway implicate non-ischaemic cardiac damage

Background

Russia has one of the highest rates of mortality from cardiovascular disease (CVD). At age 35–69 years, they are eight times higher than in neighbouring Norway. Comparing profiles of blood-based CVD biomarkers between these two populations can help identify reasons for this substantial difference in risk.

Methods

We compared age-standardised mean levels of CVD biomarkers for men and women aged 40–69 years measured in two cross-sectional population-based studies: Know Your Heart (KYH) (Russia, 2015–2018; n=4046) and the seventh wave of the Tromsø Study (Tromsø 7) (Norway, 2015–2018; n=17 646). A laboratory calibration study was performed to account for inter-laboratory differences.

Results

Levels of total, low-density lipoprotein-, high-density lipoprotein-cholesterol and triglycerides were comparable in KYH and Tromsø 7 studies. N-terminal pro-b-type natriuretic peptide (NT-proBNP), high-sensitivity cardiac troponin T (hs-cTnT) and high-sensitivity C-reactive protein (hsCRP) were higher in KYH compared with Tromsø 7 (NT-proBNP was higher by 54.1% (95% CI 41.5% to 67.8%) in men and by 30.8% (95% CI 22.9% to 39.2%) in women; hs-cTnT—by 42.4% (95% CI 36.1% to 49.0%) in men and by 68.1% (95% CI 62.4% to 73.9%) in women; hsCRP—by 33.3% (95% CI 26.1% to 40.8%) in men and by 35.6% (95% CI 29.0% to 42.6%) in women). Exclusion of participants with pre-existing coronary heart disease (279 men and 282 women) had no substantive effect.

Conclusions

Differences in cholesterol fractions cannot explain the difference in CVD mortality rate between Russia and Norway. A non-ischemic pathway to the cardiac damage reflected by raised NT-proBNP and hs-cTnT is likely to contribute to high CVD mortality in Russia.

Exercise Hemodynamics After Aortic Valve Replacement for Severe Aortic Stenosis

BACKGROUND

Severe aortic stenosis (AS) is often accompanied by diastolic dysfunction. After aortic valve replacement (AVR), the left ventricle often undergoes considerable reverse remodeling. Despite this, diastolic dysfunction may persist after AVR. The aims of this study were to determine the incidence of elevated left ventricular (LV) filling pressure at rest and during exercise among patients with severe AS after AVR and to describe factors related to elevated LV filling pressure, especially its association with LV and left atrial remodeling and myocardial fibrosis.

METHODS

Thirty-seven patients undergoing AVR were included. Echocardiography, cardiac computed tomography, and magnetic resonance imaging were performed before AVR. An LV biopsy sample was obtained during AVR and analyzed for collagen fraction. One year after AVR, right heart catheterization with exercise was performed. A mean pulmonary capillary wedge pressure (PCWP) ≥ 28 mm Hg during exercise was considered elevated.

RESULTS

Twelve patients (32%) had elevated exercise PCWP 1 year after AVR. Exercise PCWP was highest among patients undergoing concomitant coronary artery bypass graft surgery (30 ± 7 vs 25 ± 6 mm Hg, P = .04) and among patients with preoperative stroke volume index < 35 mL/m² (28 ± 8 vs 23 ± 4 mm Hg, P < .05). Baseline LV ejection fraction was lower among patients with elevated PCWP (56 ± 8% vs 64 ± 8%, P = .01), and coronary calcium score was significantly higher (median 870 AU [interquartile range, 454-2,491 AU] vs 179 AU [interquartile range, 63-513 AU], P = .02). Conversely, exercise PCWP was not related to the presence of high LV wall mass or to the severity of AS. Among patients undergoing isolated AVR, there was a correlation between LV interstitial volume fraction and PCWP (r = 0.57, P = .01) and mean pulmonary artery pressure (r = 0.51, P = .03) during exercise.

CONCLUSIONS

Elevated filling pressure during exercise was seen in one third of patients after AVR in this population and was seen primarily among patients with coexisting ischemic heart disease or diffuse myocardial fibrosis but was unrelated to preoperative severity of AS and LV remodeling.

Biomarkers in patients with myocardial fibrosis

Myocardial fibrosis is observed in many cardiovascular diseases including hypertension, heart failure and cardiomyopathy. Myocardial fibrosis has been proved to be reversible and treatable only under timely intervention, which makes early detection and assessment of fibrosis crucial. Aside from tissue biopsy as the gold standard for the diagnosis of myocardial fibrosis, circulating biomarkers have been adopted as noninvasive assessment of this lesion. Dysregulated collagen deposition is thought to be the major cause of myocardial fibrosis. Collagens, procollagens, TGF-β, TIMP, galectin-3, and microRNAs are thought to be indicators of myocardial fibrosis. In this review, we summarize the molecules that are frequently used as biomarkers in diagnosis of cardiac fibrosis. Mechanisms of fibrosis that they take part in are also introduced.

High-Sensitive Cardiac Troponin T as an Early Biochemical Signature for Clinical and Subclinical Heart Failure: MESA (Multi-Ethnic Study of Atherosclerosis)

BACKGROUND

Although small elevations of high-sensitive cardiac troponin T (hs-cTnT) are associated with incident heart failure (HF) in the general population, the underlying mechanisms are not well defined. Evaluating the association of hs-cTnT with replacement fibrosis and progression of structural heart disease before symptoms is fundamental to understanding the potential of this biomarker in a HF prevention strategy.

METHODS

We measured hs-cTnT at baseline among 4986 participants in MESA (Multi-Ethnic Study of Atherosclerosis), a cohort initially free of overt cardiovascular disease (CVD). Cardiac magnetic resonance imaging was performed at baseline. Repeat cardiac magnetic resonance was performed 10 years later among 2831 participants who remained free of interim CVD events; of these, 1723 received gadolinium-enhanced cardiac magnetic resonance for characterization of replacement fibrosis by late gadolinium enhancement. Progression of subclinical CVD was defined by 10-year change in left ventricular structure and function. Associations of hs-cTnT with incident HF, CV-related mortality, and coronary heart disease were estimated using Cox regression models.

RESULTS

Late gadolinium enhancement for replacement fibrosis was detectable in 6.3% participants without interim CVD events by follow-up cardiac magnetic resonance. A graded association was observed between higher baseline hs-cTnT categories and late gadolinium enhancement (≥7.42 ng/L versus <limit of detection [<3 ng/L]; adjusted odds ratio, 2.87; 95% confidence interval, 1.38-5.94). Higher hs-cTnT was also associated with a greater probability of an increase in LV mass >12% (highest category versus <limit of detection; odds ratio, 1.50; 95% confidence interval, 1.09-2.07), but not with decline in left ventricular ejection fraction. The risk of incident HF was greater for higher hs-cTnT (≥8.81 ng/L versus <limit of detection; adjusted hazards ratio, 5.59; 95% CI, 2.97-10.68).

CONCLUSIONS

hs-cTnT levels are associated with replacement fibrosis and progressive changes in left ventricular structure in CVD-free adults, findings that may precede HF symptoms by years. Minor elevations of hs-cTnT may represent a biochemical signature of early subclinical cardiac disease, providing an opportunity for targeted preventive interventions.

Late gadolinium enhancement on cardiac magnetic resonance predicts coronary vasomotor abnormality and myocardial lactate production in patients with chronic heart failure

Myocardial fibrosis and microvascular dysfunction are key determinants of outcome in heart failure (HF); we examined their relationship in patients with HF. Our study included 61 consecutive patients with HF but without coronary stenosis. All underwent gadolinium-enhanced cardiac magnetic resonance to evaluate late gadolinium enhancement (LGE) and an acetylcholine (ACh) provocation test to evaluate microvascular dysfunction. During the ACh provocation test, we sampled blood simultaneously from the coronary sinus and aortic root to compare lactate concentrations. We quantified coronary blood flow volume using an intracoronary Doppler-tipped guidewire. We detected LGE in 34 patients (LGE-positive); 27 were LGE-negative. Coronary blood flow volume increased significantly after the ACh provocation test only in LGE-negative patients (before vs. after ACh, 47.5 ± 36.8 vs. 69.2 ± 48.0 ml/min, respectively; p = 0.004). The myocardial lactate extraction ratio (LER) significantly decreased after the ACh test in both groups (LGE-negative, p = 0.001; LGE-positive, p < 0.001), significantly more so in the LGE-positive group (p = 0.017). Multivariate logistic regression analysis showed that a post-ACh LER < 0 (indicating myocardial lactate production) was a significant predictor of LGE-positivity (odds ratio 4.54; 95 % confidence interval 1.38-14.93; p = 0.013). In the LGE-positive group, an LGE volume greater than the median significantly predicted a post-ACh LER of <0 (p = 0.042; odds ratio 6.02; 95 % confidence interval 1.07-33.86). ACh-provoked coronary vasomotor abnormality is closely correlated with myocardial fibrosis in patients with HF but without organic coronary stenosis. Coronary vasomotor abnormalities in fibrotic myocardium may worsen HF.

Troponin T-release associates with cardiac radiation doses during adjuvant left-sided breast cancer radiotherapy

Background

Adjuvant radiotherapy (RT) for left-sided breast cancer increases cardiac morbidity and mortality. For the heart, no safe radiation threshold has been established. Troponin T is a sensitive marker of myocardial damage. Our aim was to evaluate the effect of left-sided breast cancer RT on serum high sensitivity troponin T (hscTnT) levels and its association with cardiac radiation doses and echocardiographic parameters.

Methods

A total of 58 patients with an early stage, left-sided breast cancer or ductal carcinoma in situ (DCIS) who received adjuvant breast RT without prior chemotherapy were included in this prospective, non-randomized study. Serum samples were taken before, during and after RT. An increase of hscTnT >30 % was predefined as significant. A comprehensive 2D echocardiograph and electrocardiogram (ECG) were performed before and after RT. Dose-volume histograms (DVHs) were generated for different cardiac structures.

Results

The hscTnT increased during RT from baseline in 12/58 patients (21 %). Patients with increased hscTnT values (group A, N = 12) had significantly higher radiation doses for the whole heart (p = 0.02) and left ventricle (p = 0.03) than patients without hscTnT increase (group B, N = 46). For the left anterior descending artery (LAD), differences between groups A and B were found in volumes receiving 15 Gy (p = 0.03) and 20 Gy (p = 0.03) Furthermore, after RT, the interventricular septum thickened (p = 0.01), and the deceleration time was prolonged (p = 0.008) more in group A than in group B.

Conclusions

The increase in hscTnT level during adjuvant RT was positively associated with the cardiac radiation doses for the whole heart and LV in chemotherapy-naive breast cancer patients. Whether these acute subclinical changes increase the risk of excessive long-term cardiovascular morbidity or mortality, will be addressed in the follow-up of our patients.

Relationship between high-sensitivity cardiac troponin I and blood pressure among young and healthy adults

BACKGROUND

The aim of this study was to evaluate the relationship of cardiac troponin (cTn) levels with conventional and ambulatory blood pressure (BP) in young and healthy adults.

METHODS

We performed a population based cross-sectional analysis among 2,072 young and healthy adults aged 25-41 years free of cardiovascular disease and diabetes mellitus. cTnI was measured using a highly sensitive (hs) assay. The relationships of high sensitivity cardiac tropononin I (hs-cTnI) with office and 24-hour BP were assessed using multivariable regression analyses.

RESULTS

Median age was 37 years and 975 (47%) participants were male. hs-cTnI levels were detectable in 2,061 (99.5%) individuals. Median (interquartile range) hs-cTnI levels were 0.98 (0.71; 1.64) ng/L among men and 0.48 (0.33; 0.71) ng/L among women. Systolic BP, but not diastolic BP, gradually increased across hs-cTnI quartiles (118, 120, 121, and 122 mm Hg for conventional BP; P = 0.0002; 122, 123, 124, and 124 mm Hg for 24-hour BP, P = 0.0001). In multivariable linear regression analyses, the β estimates for systolic BP per 1-unit increase in log transformed hs-cTnI were 2.52 for conventional BP (P = 0.0001); 2.75 for 24-hour BP (P < 0.0001); 2.71 and 2.41 (P < 0.0001 and P = 0.0002) for day and nighttime BP, respectively. There was a significant relationship between hs-cTnI and the Sokolow-Lyon Index (odds ratio (95% confidence interval): 2.09 (1.37; 3.18), P < 0.001).

CONCLUSION

Using a hs assay, hs-cTnI was detectable in virtually all participants of a young and healthy population. hs-cTnI was independently associated with systolic BP and left ventricular hypertrophy.

Galectin-3 and myocardial fibrosis in nonischemic dilated cardiomyopathy

BACKGROUND

Left ventricular (LV) fibrosis, assessed by late gadolinium enhancement (LGE) at cardiac magnetic resonance imaging (MRI), is a marker of LV remodeling, and holds prognostic value in nonischemic dilated cardiomyopathy (NICM). Galectin-3 has been shown to participate in tissue fibrogenesis and to be a prognosticator in heart failure. Our aim was to investigate the relationships between galectin-3 circulating level and myocardial fibrosis at MRI in patients with NICM.

METHODS AND RESULTS

One-hundred-fifty patients were enrolled (males 73%; age 58, SD 14 years), with a NICM diagnosis according to the World Health Organization criteria. All patients underwent a comprehensive clinical assessment and biohumoral characterization, including galectin-3 assay, and cardiac MRI, with LGE assessment of fibrosis. Median galectin-3 value was 14.4 ng/mL (IQR 11.7-19.0 ng/mL), and LGE was detected in 106 (71%) patients. Patients with LGE had higher galectin-3 than those without (15.4, 11.8-21.0, vs 13.1, 11.7-16.4 ng/mL, p=0.006). Among univariate predictors of LGE presence (galectin-3, male sex, disease duration, arterial hypertension, left and right ventricular ejection fraction, left ventricular stroke volume), galectin-3 maintained its predictive value at multivariate analysis, together with sex, hypertension, disease duration and right ventricular ejection fraction. At receiver operating characteristic analysis the optimal galectin-3 cut-off for LGE prediction was 14.6 ng/mL (AUC 0.651, sensitivity 57%, specificity 73%).

CONCLUSIONS

Galectin-3 is associated with LGE-assessed myocardial replacement fibrosis in patients with NICM. These results support the hypothesis that galectin-3 is involved in cardiac fibrosis and remodeling in NICM, and that its assay may help to select subgroups at higher risk.