Amyloid myopathy: expanding the clinical spectrum of transthyretin amyloidosis-case report and literature review.

We identified two patients with transthyretin (ATTR) amyloid myopathy (one ATTR variant amyloidosis, ATTRv; one wild-type ATTR amyloidosis, ATTRwt). Myopathy was the initial manifestation in ATTRwt, whereas it followed neuropathy and cardiomyopathy in ATTRv. The ATTRwt patient showed muscular tracer uptake on 99mTc-DPD planar scintigraphy at the time of initial diagnosis, consistent with ATTR amyloid myopathy. The ATTRv patient underwent heart transplantation because of progressive heart failure. Within the next two years, progressive myopathic symptoms and extracardiac tracer uptake on 99mTc-DPD planar scintigraphy were documented, attributable to ATTR amyloid myopathy. Interstitial amyloid deposits were confirmed by muscle biopsy in both patients, with a particularly high amyloid burden in the adipose tissue. This case report highlights the frequent concomitant presence of cardiac ATTR amyloidosis and ATTR amyloid myopathy. ATTR amyloid myopathy may precede cardiac manifestation in ATTRwt or occur after heart transplantation in ATTRv. Due to the high diagnostic accuracy of 99mTc-DPD scintigraphy for detecting ATTR amyloid myopathy and the emergence of novel therapeutics, it is important to increase the awareness of its presence.

Smooth Muscle Specific Ablation of CXCL12 in Mice Downregulates CXCR7 Associated with Defective Coronary Arteries and Cardiac Hypertrophy.

The chemokine CXCL12 plays a fundamental role in cardiovascular development, cell trafficking, and myocardial repair. Human genome-wide association studies even have identified novel loci downstream of the CXCL12 gene locus associated with coronary artery disease and myocardial infarction. Nevertheless, cell and tissue specific effects of CXCL12 are barely understood. Since we detected high expression of CXCL12 in smooth muscle (SM) cells, we generated a SM22-alpha-Cre driven mouse model to ablate CXCL12 (SM-CXCL12-/-). SM-CXCL12-/- mice revealed high embryonic lethality (50%) with developmental defects, including aberrant topology of coronary arteries. Postnatally, SM-CXCL12-/- mice developed severe cardiac hypertrophy associated with fibrosis, apoptotic cell death, impaired heart function, and severe coronary vascular defects characterized by thinned and dilated arteries. Transcriptome analyses showed specific upregulation of pathways associated with hypertrophic cardiomyopathy, collagen protein network, heart-related proteoglycans, and downregulation of the M2 macrophage modulators. CXCL12 mutants showed endothelial downregulation of the CXCL12 co-receptor CXCR7. Treatment of SM-CXCL12-/- mice with the CXCR7 agonist TC14012 attenuated cardiac hypertrophy associated with increased pERK signaling. Our data suggest a critical role of smooth muscle-specific CXCL12 in arterial development, vessel maturation, and cardiac hypertrophy. Pharmacological stimulation of CXCR7 might be a promising target to attenuate adverse hypertrophic remodeling.

High Body Mass Index is Associated with Elevated Blood Levels of Progerin mRNA.

Obesity is a well-described risk factor resulting in premature aging of the cardiovascular system ultimately limiting longevity. Premature cardiac death and aging is the hallmark of Hutchinson-Gilford syndrome (HGPS), a disease caused by defined mutations in the lamin A gene leading to a shortened prelamin A protein known as progerin. Since small amounts of progerin are expressed in healthy individuals we aimed to investigate the association of Body-Mass-Index (BMI) with respect to expression of progerin mRNA in blood samples of patient with known cardiovascular disease. In this cross-sectional retrospective analysis, 111 patients were consecutively included of which 46 were normal (BMI < 25 kg/m2) and 65 overweight (BMI ≥ 25.0 kg/m2). Blood samples were analyzed for quantitative expression of progerin mRNA. Progerin as well as high-sensitive C-Reactive Protein (hs-CRP) levels were significantly upregulated in the overweight group. Linear regression analyses showed a significant positive correlation of BMI and progerin mRNA (n = 111; r = 0.265, p = 0.005), as well as for hs-CRP (n = 110; r = 0.300, p = 0.001) and for Hb1Ac (n = 110; r = 0.336, p = 0.0003). Our data suggest that BMI strongly correlates with progerin mRNA expression and inflammation. Progerin might contribute to well described accelerated biologic aging in obese individuals.

Aetiology, ejection fraction and mortality in chronic heart failure: a mediation analysis.

OBJECTIVE: Clinical decision making in chronic heart failure (CHF) is based primarily on left ventricular ejection fraction (LVEF), and only secondarily on aetiology of the underlying disease. Our aim was to investigate the mediating role of LVEF in the relationship between aetiology and mortality. METHODS: Using data of 2056 Austrian patients with CHF (mean age 57.2 years; mean follow-up 8.8 years), effects of aetiology on LVEF and overall mortality were estimated using multivariable-adjusted linear and Cox regression models. In causal mediation analyses, we decomposed the total effect of aetiology on mortality into direct and indirect (mediated through LVEF) effects. RESULTS: For the analysed aetiologies (dilated (DCM, n=1009) and hypertrophic (HCM, n=89) cardiomyopathy; ischaemic (IHD, n=529) and hypertensive (HHD, n=320) heart disease; cardiac amyloidosis (CA, n=109)), the effect of LVEF on mortality was similar (HR5%-points lower LVEF=1.07, 95% CI 1.04 to 1.10; pinteraction=0.718). HCM and CA were associated with significantly higher, and IHD and DCM with significantly lower LVEF compared with other aetiologies. Compared with respective other aetiologies, the corresponding total effect HRs for mortality were 0.77 (95% CI 0.67 to 0.89), 0.47 (95% CI 0.25 to 0.88), 1.40 (95% CI 1.21 to 1.62), 0.79 (95% CI 0.67 to 0.95) and 2.36 (95% CI 1.81 to 3.08) for DCM, HCM, IHD, HHD and CA, respectively. CA had the highest mortality despite a HRindirect effect of 0.74 (95% CI 0.65 to 0.83). For all other aetiologies, <20% of the total mortality effects were mediated through LVEF. CONCLUSIONS: The direct effect of aetiology on mortality dominates the indirect effect through LVEF. Therefore, clarification of aetiology is as important as measurement of LVEF.

Imbalance of Iron Availability and Demand in Patients With Acute and Chronic Heart Failure.

BACKGROUND: Iron deficiency (ID) is a frequent comorbidity in patients with acute (AHF) and chronic heart failure (CHF) associated with morbidity and death. We aimed to better characterize iron homeostasis in patients with heart failure applying different biomarkers and to evaluate the accuracy of current ID definition by the European Society of Cardiology/American College of Cardiology/American Heart Association to indicate tissue iron availability and demand. METHODS AND RESULTS: We performed a retrospective cohort study investigating 277 patients with AHF and 476 patients with CHF between February 2021 and May 2022. Patients with AHF had more advanced ID than patients with CHF, reflected by increased soluble transferrin receptor and soluble transferrin receptor-ferritin index, and lower ferritin, serum iron, transferrin saturation, hepcidin, and reticulocyte hemoglobin. Decreased iron availability or increased tissue iron demand, reflected by increased soluble transferrin receptor-ferritin index and decreased reticulocyte hemoglobin, was found in 84.1% (AHF) and 28.0% (CHF) with absolute ID and in 50.0% (AHF) and 10.5% (CHF) with combined ID according to the current European Society of Cardiology/American College of Cardiology/American Heart Association-based ID definition. Low hepcidin expression as an indicator of systemic ID was found in 91.1% (AHF) and 80.4% (CHF) of patients with absolute ID and in 32.3% (AHF) and 18.8% (CHF) of patients with combined ID. ID definitions with higher specificity reduce the need for iron supplementation by 25.5% in patients with AHF and by 65.6% in patients with CHF. CONCLUSIONS: Our results suggest that the current European Society of Cardiology/American College of Cardiology/American Heart Association-based ID definition might overestimate true ID, particularly in CHF. More stringent thresholds for ID could more accurately identify patients with heart failure with reduced tissue iron availability who benefit from intravenous iron supplementation.

Roxadustat Attenuates Adverse Remodeling Following Myocardial Infarction in Mice.

Activation of the CXCL12/CXCR4/ACKR3 axis is known to aid myocardial repair through ischemia-triggered hypoxia-inducible factor-1α (HIF-1α). To enhance the upregulation of HIF-1α, we administered roxadustat, a novel prolyl hydroxylase inhibitor (PHI) clinically approved by the European Medicines Agency 2021 for the treatment of renal anemia, with the purpose of improving LV function and attenuating ischemic cardiomyopathy. METHODS: We evaluated roxadustat's impact on HIF-1 stimulation, cardiac remodeling, and function after MI. Therefore, we analyzed nuclear HIF-1 expression, the mRNA and protein expression of key HIF-1 target genes (RT-PCR, Western blot), inflammatory cell infiltration (immunohistochemistry), and apoptosis (TUNEL staining) 7 days after MI. Additionally, we performed echocardiography in male and female C57BL/6 mice 28 days post-MI. RESULTS: We found a substantial increase in nuclear HIF-1, associated with an upregulation of HIF-1α target genes like CXCL12/CXCR4/ACKR3 at the mRNA and protein levels. Roxadustat increased the proportion of myocardial reparative M2 CD206+ cells, suggesting beneficial alterations in immune cell migration and a trend towards reduced apoptosis. Echocardiography showed that roxadustat treatment significantly preserved ejection fraction and attenuated subsequent ventricular dilatation, thereby reducing adverse remodeling. CONCLUSIONS: Our findings suggest that roxadustat is a promising clinically approved treatment option to preserve myocardial function by attenuating adverse remodeling.

Decongestion in Acute Heart Failure-Time to Rethink and Standardize Current Clinical Practice?

Most episodes of acute heart failure (AHF) are characterized by increasing signs and symptoms of congestion, manifested by edema, pleura effusion and/or ascites. Immediately and repeatedly administered intravenous (IV) loop diuretics currently represent the mainstay of initial therapy aiming to achieve adequate diuresis/natriuresis and euvolemia. Despite these efforts, a significant proportion of patients have residual congestion at discharge, which is associated with a poor prognosis. Therefore, a standardized approach is needed. The door to diuretic time should not exceed 60 min. As a general rule, the starting IV dose is 20-40 mg furosemide equivalents in loop diuretic naïve patients or double the preexisting oral home dose to be administered via IV. Monitoring responses within the following first hours are key issues. (1) After 2 h, spot urinary sodium should be ≥50-70 mmol/L. (2) After 6 h, the urine output should be ≥100-150 mL/hour. If these target measures are not reached, the guidelines currently recommend a doubling of the original dose to a maximum of 400-600 mg furosemide per day and in patients with severely impaired kidney function up to 1000 mg per day. Continuous infusion of loop diuretics offers no benefit over intermittent boluses (DOSE trial). Emerging evidence by recent randomized trials (ADVOR, CLOROTIC) supports the concept of an early combination diuretic therapy, by adding either acetazolamide (500 mg IV once daily) or hydrochlorothiazide. Acetazolamide is particularly useful in the presence of a baseline bicarbonate level of ≥27 mmol/L and remains effective in the presence of preexisting/worsening renal dysfunction but should be used only in the first three days to prevent severe metabolic disturbances. Patients should not leave the hospital when they are still congested and/or before optimized long-term guideline-directed medical therapy has been initiated. Special attention should be paid to AHF patients during the vulnerable post-discharge period, with an early follow-up visit focusing on up-titrate treatments of recommended doses within 2 weeks (STRONG-HF).

Correlation of 99mTc-DPD bone scintigraphy with histological amyloid load in patients with ATTR cardiac amyloidosis.

BACKGROUND: The significance of measuring 99mTc-labelled-3,3-diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) in transthyretin (ATTR) cardiac amyloidosis has not been adequately studied. This single-centre observational study evaluated the correlation between 99mTc-DPD scintigraphy and histological amyloid load in endomyocardial biopsy (EMB). METHODS: Twenty-eight patients with biopsy-proven ATTR amyloidosis and concomitantly available 99mTc-DPD scintigraphy were included. Visual Perugini scoring, and (semi-)quantitative analysis of cardiac 99mTc-DPD uptake by planar whole-body imaging and single photon emission computed tomography (SPECT/CT) using regions of interest (ROI) were performed. From this, heart-to-whole-body ratio (H/WB) and heart-to-contralateral-chest ratio (H/CL) were calculated. The histological amyloid load was quantified using two different staining methods. RESULTS: Increased cardiac tracer uptake was documented in all patients (planar: ROImean 129 ± 37 cps; SPECT/CT: ROImean 369 ± 142 cps). Histological amyloid load (19 ± 13%) significantly correlated with Perugini score (r = 0.69, p < .001) as well as with cardiac 99mTc-DPD uptake (planar: r = 0.64, p < .001; H/WB: r = 0.50, p = .014; SPECT/CT: r = 0.53, p = .008; H/CL: r = 0.43, p = .037) (results are shown for correlations with Congo Red-staining). CONCLUSION: In ATTR, cardiac 99mTc-DPD uptake significantly correlated with histological amyloid load in EMB. Further studies are needed to implement thresholds in cardiac 99mTc-DPD uptake measurements for risk stratification and guidance of therapy.

Eosinophilic myocarditis complicated by permanent atrioventricular nodal block: a case report.

Background: Eosinophilic myocarditis (EM) is a rare disease with different clinical pictures and disease courses. Little literature is available on the various courses of the disease. Case summary: A previously healthy 44-year-old male patient presented with acute heart failure and developed complete atrioventricular (AV) block requiring pacing. Acute heart failure was managed with inotropic support, non-invasive ventilation, and implantation of a permanent AV-sequential pacemaker. Cardiac magnetic resonance imaging was suggestive of myocarditis and endomyocardial biopsy diagnosed EM histologically. Endomyocardial biopsy was essential for definite aetiologic assignment, thus dispelling initial reservations about immunosuppressive therapy. Final treatment strategy consisted of steroids and Azathioprine. Discussion: Endomyocardial biopsy is essential to establish diagnosis and targeted treatment in EM, which can rapidly lead to life-threatening conditions. Left ventricular function recovered within 2 weeks in response to immunosuppression and the patient was consistently well during follow-up. Despite the otherwise good response to immunosuppression, complete AV block continued over time.

ZMPSTE24 Is Associated with Elevated Inflammation and Progerin mRNA.

Lamins are important filaments forming the inner nuclear membrane. Lamin A is processed by zinc metalloproteinase (ZMPSTE24). Failure to cleave a truncated form of prelamin A-also called progerin-causes Hutchinson-Gilford progeria syndrome a well-known premature aging disease. Minor levels of progerin are readily expressed in the blood of healthy individuals due to alternative splicing. Previously, we found an association of increased progerin mRNA with overweight and chronic inflammation (hs-CRP). Here, we aimed to elucidate correlations of ZMPSTE24, lamin A/C and progerin with the inflammatory marker hs-CRP. In this retrospective, cross-sectional study we analyzed blood samples from 110 heart failure patients for quantitative mRNA expression of ZMPSTE24, lamin A/C, progerin and hs-CRP protein. Spearman correlations and linear regression analyses including adjustments for age, gender and ejection fraction showed a significant positive correlation of lnprogerin with lnZMPSTE24 (n = 110; r = 0.33; p = 0.0004) and lnlamin A/C (n = 110; r = 0.82, p < 0.0001), whereas no association was observed between lnlamin A/C and lnZMPSTE24 expression. Further analyses showed a significant positive correlation of lnhs-CRP with lnZMPSTE24 (n = 110; r = 0.21; p = 0.01) and lnlamin A/C (n = 110; r = 0.24; p = 0.03). We conclude that chronic inflammation is associated with increased expression of ZMPSTE24 and lamin A/C mRNA. Both markers also positively correlate with increased expression of the premature aging marker progerin which may be linked to cardiovascular aging.

Heart failure from ATTRwt amyloid cardiomyopathy is associated with poor prognosis.

AIMS: Amyloid cardiomyopathy is an underappreciated cause of morbidity and mortality. Recent evidence suggests that ATTR wild-type cardiomyopathy (ATTRwt-CM) is probably much more common than widely appreciated. So far, no data are available on comparison of mortality from ATTRwt-CM and other heart failure aetiologies. METHODS AND RESULTS: This was a retrospective, observational, cohort study of 2251 patients and their data collected prospectively from May 2000 to June 2018. Long-term mortality was the main outcome measure. Underlying cardiomyopathies were classified as amyloid CM (6.1%) [ATTRwt 3.0%; light-chain amyloidosis (AL) 3.1%], dilated CM (dCMP) (46.4%), ischaemic heart disease (IHD) (24.4%), hypertensive heart disease (HHD) (14.6%), hypertrophic CM (HCM) (5.1%), and valvular heart disease (VHD) (3.4%). Median duration of follow-up was 7.1 years (interquartile range 3.4-11.3). Five-year overall survival in the whole cohort was 80.1%. In multivariate analysis, individuals with amyloid CM were 3.74 times [95% confidence interval (CI) 2.72-5.14; P < 0.001] more likely to die of any reason than were individuals with dCMP. Mortality was higher in AL-CM compared with ATTRwt-CM [hazard ratio (HR) 2.88; 95% CI 1.48-5.58; P = 0.002]. Mortality rates in patients with ATTRwt-CM were higher than in patients with dCMP (HR 1.96; 95% CI 1.24-3.22; P = 0.007), HCM (HR 2.94; 95% CI 1.28-6.67; P = 0.011), HHD (HR 2.08; 95% CI 1.27-3.45; P = 0.004), VHD (HR 2.38; 95% CI 1.30-4.35; P = 0.005), or left ventricular ejection fraction ≥ 40% (HR 1.99; 95% CI 1.12-3.52; P = 0.018). CONCLUSIONS: Our study demonstrates that amyloid CM is independently associated with poor survival among patients with various causes of heart failure. ATTRwt-CM had a better long-term prognosis than did AL-CM, but was associated with higher mortality than were dCMP, HCM, HHD, VHD, and heart failure with preserved or mid-range ejection fraction.

Catheter-based edge-to-edge mitral valve repair for pulmonary pressure reduction and to postpone heart transplantation in a teenaged patient.

We report a case of catheter-based edge-to-edge mitral valve repair in a teenage male patient with non-ischaemic cardiomyopathy to improve pulmonary hypertension secondary to severe functional mitral regurgitation (FMR) to defer anticipated heart transplantation. A 19-year-old patient with previous history of fulminant myocarditis followed by markedly left ventricular dysfunction presented with severe mitral regurgitation 3 years after initial recovery. Slightly over time, deterioration of FMR was associated with gradual increase in pulmonary artery pressures despite optimal medical therapy. MitraClip implantation in this young patient was successfully performed with sustainable improvement of pulmonary hypertension.

Upregulation of the aging related LMNA splice variant progerin in dilated cardiomyopathy.

BACKGROUND: Mutations in the LMNA gene are a common cause (6-8%) of dilated cardiomyopathy (DCM) leading to heart failure, a growing health care problem worldwide. The premature aging disease Hutchinson-Gilford syndrome (HGPS) is also caused by defined mutations in the LMNA gene resulting in activation of a cryptic splice donor site leading to a defective truncated prelamin A protein called progerin. Low levels of progerin are expressed in healthy individuals associated with ageing. Here, we aimed to address the role of progerin in dilated cardiomyopathy. METHODS AND RESULTS: mRNA expression of progerin was analyzed in heart tissue of DCM (n = 15) and non-failing hearts (n = 10) as control and in blood samples from patients with DCM (n = 56) and healthy controls (n = 10). Sequencing confirmed the expression of progerin mRNA in the human heart. Progerin mRNA levels derived from DCM hearts were significantly upregulated compared to controls (1.27 ± 0.42 vs. 0.81 ± 0.24; p = 0.005). In contrast, progerin mRNA levels in whole blood cells were not significantly different in DCM patients compared to controls. Linear regression analyses revealed that progerin mRNA in the heart is significantly negatively correlated to ejection fraction (r = -0.567, p = 0.003) and positively correlated to left ventricular enddiastolic diameter (r = 0.551, p = 0.004) but not with age of the heart per se. Progerin mRNA levels were not influenced by inflammation in DCM hearts. Immunohistochemistry and Immunofluorescence analysis confirmed increased expression of progerin protein in cell nuclei of DCM hearts associated with increased TUNEL+ apoptotic cells. CONCLUSION: Our data suggest that progerin is upregulated in human DCM hearts and strongly correlates with left ventricular remodeling. Progerin might be involved in progression of heart failure and myocardial aging.

Prolyl-hydroxylase inhibition induces SDF-1 associated with increased CXCR4+/CD11b+ subpopulations and cardiac repair.

SDF-1/CXCR4 activation facilitates myocardial repair. Therefore, we aimed to activate the HIF-1α target genes SDF-1 and CXCR4 by dimethyloxalylglycine (DMOG)-induced prolyl-hydroxylase (PH) inhibition to augment CXCR4+ cell recruitment and myocardial repair. SDF-1 and CXCR4 expression was analyzed under normoxia and ischemia ± DMOG utilizing SDF-1-EGFP and CXCR4-EGFP reporter mice. In bone marrow and heart, CXCR4-EGFP was predominantly expressed in CD45+/CD11b+ leukocytes which significantly increased after myocardial ischemia. PH inhibition with 500 µM DMOG induced upregulation of SDF-1 mRNA in human microvascular endothelial cells (HMEC-1) and aortic vascular smooth muscle cells (HAVSMC). CXCR4 was highly elevated in HMEC-1 but almost no detectable in HAVSMC. In vivo, systemic administration of the PH inhibitor DMOG without pretreatment upregulated nuclear HIF-1α and SDF-1 in the ischemic mouse heart associated with increased recruitment of CD45+/CXCR4-EGFP+/CD11b+ cell subsets. Enhanced PH inhibition significantly upregulated reparative M2 like CXCR4-EGFP+ CD11b+/CD206+ cells compared to inflammatory M2-like CXCR4-EGFP+ CD11b+/CD86+ cells associated with reduced apoptotic cell death, increased neovascularization, reduced scar size, and an improved heart function after MI. In summary, our data suggest increased PH inhibition as a promising tool for a customized upregulation of SDF-1 and CXCR4 expression to attract CXCR4+/CD11b+ cells to the ischemic heart associated with increased cardiac repair. KEY MESSAGES: DMOG-induced prolyl-hydroxylase inhibition upregulates SDF-1 and CXCR4 in human endothelial cells. Systemic application of DMOG upregulates nuclear HIF-1α and SDF-1 in vivo. Enhanced prolyl-hydroxylase inhibition increases mainly CXCR4+/CD11b+ cells. DMOG increased reparative M2-like CD11b+/CD206+ cells compared to M1-like cells after MI. Enhanced prolyl-hydroxylase inhibition improved cardiac repair and heart function.