Left ventricular reverse remodeling is not related to biopsy-detected extracellular matrix fibrosis and serum markers of fibrosis in dilated cardiomyopathy, regardless of the definition used for LVRR

Relation between cardiac magnetic resonance-assessed interstitial fibrosis and diastolic dysfunction in heart failure due to dilated cardiomyopathy

Background

Dilated cardiomyopathy (DCM) is distinguished by left ventricle (LV) dilation accompanied by systolic dysfunction. However, some studies suggested also a high prevalence of LV diastolic dysfunction (LVDD), similar to a general cohort of heart failure (HF) with reduced ejection fraction (LVEF). The bulk of evidence, mostly arising from basic studies, suggests a causative link between cardiac fibrosis (CF) and LVDD. However, still, there remains a scarcity of data on LVDD and CF. Therefore, the aim of the study was to investigate the association between CF and LVDD in DCM patients.

Methods

The study population was composed of 102 DCM patients. Replacement CF was evaluated qualitatively (late gadolinium enhancement - LGE) and quantitively (LGE extent); interstitial cardiac fibrosis was assessed via extracellular volume (ECV). Based on echocardiography patients were divided into normal and elevated left atrial pressure (nLAP, eLAP) groups.

Results

42 % of patients had eLAP. They displayed higher troponin and NT-proBNP. Both groups did not differ in terms of LGE presence and extent; however, eLAP patients had larger ECV: 30.1 ± 5.6 % vs. 27.8 ± 3.9 %, p = 0.03. Moreover, ECV itself was found to be an independent predictor of LVDD (OR = 0.901; 95 %CI 0.810-0.999; p = 0.047; normalised for LVEF and RVOT diameter).

Conclusions

More than two-in-five DCM patients had at least moderate LVDD. The mere presence or extent of replacement cardiac fibrosis is similar in patients with nLAP and eLAP. On the other hand, interstitial cardiac fibrosis is more pronounced in those with a higher grade of LVDD. ECV was found to be an independent predictor of LVDD in DCM.

New Frontiers in Electrocardiography, Cardiac Arrhythmias, and Arrhythmogenic Disorders

In recent decades, diagnosing, risk-stratifying, and treating patients with primary electrical diseases, as well as heart rhythm disorders, have improved substantially [...].

Comparison of Clinical Course and Outcomes between Dilated and Hypokinetic Non-Dilated Cardiomyopathy

BACKGROUND

By definition, dilated cardiomyopathy (DCM) is characterized by enlargement of the left ventricular (LV) cavity, and systolic dysfunction. However, in 2016 ESC introduced a new clinical entity - hypokinetic non-dilated cardiomyopathy (HNDC). HNDC is defined as LV systolic dysfunction without LV dilatation. However, the diagnosis of HNDC has so far rarely been made by a cardiologist, and it is unknown whether "classic" DCM differs from HNDC in terms of clinical course and outcomes.

OBJECTIVES

Comparison of heart failure profiles and outcomes between patients with "classic" dilated (DCM) and HNDCs.

METHOD

We retrospectively analysed 785 DCM patients, defined as impaired left ventricle (LV) systolic function (ejection fraction [LVEF] <45%) in the absence of coronary artery disease, valve disease, congenital heart disease, and severe arterial hypertension. "Classic" DCM was diagnosed when LV dilatation was present (LV end-diastolic diameter >52 mm/58 mm in women/men); otherwise, HNDC was diagnosed. After 47 ± 31 months, the all-cause mortality and composite endpoint (all-cause mortality, heart transplant - HTX, left ventricle assist device implantation - LVAD) were assessed.

RESULTS

There were 617 (79%) patients with LV dilatation. Patients with "classic" DCM differed from HNDC in terms of clinically relevant parameters [hypertension (47% vs. 64%, p = 0.008), ventricular tachyarrhythmias (29% vs. 15%, p = 0.007), NYHA class (2.5 ± 0.9 vs. 2.2 ± 0.8, p = 0.003)], had lower cholesterol (LDL: 2.9 ± 1.0 vs. 3.2 ± 1.1 mmol/L, p = 0.049), and higher N-terminal pro-brain natriuretic peptide (3,351 ± 5,415 vs. 2,563 ± 8584 pg/mL, p = 0.0001) and required higher diuretics dosages (57.8 ± 89.5 vs. 33.7 ± 48.7 mg/day, p ≤ 0.0001). All of their chambers were larger (LVEDd: 68.3 ± 4.5 vs. 52.7 ± 3.5 mm, p < 0.0001) and they had lower LVEF (25.2 ± 9.4 vs. 36.6 ± 11.7%, p < 0.0001). During the follow-up, there were 145 (18%) composite endpoints ("classic" DCM vs. HNDC: 122 [20%] vs. 26 [18%], p = 0.22): deaths (97 [16%] vs. 24 [14%], p = 0.67), HTX (17 [4%] vs. 4 [4%], p = 0.97) and LVAD (19 [5%] vs. 0 [0%], p = 0.03). Both groups did not differ in terms of all-cause mortality (p = 0.70), cardiovascular (CV) mortality (p = 0.37) and composite endpoint (p = 0.26).

CONCLUSIONS

LV dilatation was absent in more than one-fifth of DCM patients. HNDC patients had less severe heart failure symptoms, less advanced cardiac remodelling, and required lower diuretics dosages. On the other hand, "classic" DCM and HNDC patients did not differ in terms of all-cause mortality, CV mortality, and composite endpoint.

Relationships between Pulmonary Hypertension Risk, Clinical Profiles, and Outcomes in Dilated Cardiomyopathy

Pulmonary hypertension (PH) in patients with heart failure (HF) contributes to a poorer prognosis. However, in those with dilated cardiomyopathy (DCM), the true prevalence and role of PH is unclear. Therefore, this study aimed to analyze the profile of DCM patients at various levels of PH risk, determined via echocardiography, and its impact on outcomes. The 502 DCM in- and out-patient records were retrospectively analyzed. Information on patient status was gathered after 45.9 ± 31.3 months. Patients were divided into 3 PH-risk groups based on results from echocardiography measurements: low (L, n = 239, 47.6%), intermediate (I, n = 153, 30.5%), and high (H, n = 110, 21.9%). Symptom duration, atrial fibrillation, ventricular tachyarrhythmia, ejection fraction, right atrial area, and moderate or severe mitral regurgitation were found to be independently associated with PH risk. During the follow-up period, 83 (16.5%) DCM patients died: 29 (12.1%) in L, 31 (20.3%) in I, and 23 (20.9%) in H. L-patients had a significantly lower risk of all-cause death (L to H: HR 0.55 (95%CI 0.32–0.98), p = 0.01), while no differences in prognosis were found between I and H. In conclusion, over one in five DCM patients had a high PH risk, and low PH risk was associated with better prognoses.

Wisteria floribunda agglutinin staining for the quantitative assessment of cardiac fibrogenic activity in a mouse model of dilated cardiomyopathy

Cardiac fibrosis is a typical phenomenon in failing hearts for most cardiac diseases, including dilated cardiomyopathy (DCM), and its specific detection and quantification are crucial for the analysis of cardiac remodeling. Since cardiac fibrosis is characterized by extensive remodeling of the myocardial extracellular matrix (ECM), in which glycoproteins are the major components, we assumed that fibrosis-related alterations in the cardiac glycome and glycoproteome would be suitable targets for the detection of cardiac fibrosis. Here, we compared protein glycosylation between heart tissues of normal and DCM model mice by laser microdissection-assisted lectin microarray. Among 45 lectins, Wisteria floribunda agglutinin (WFA) was selected as the most suitable lectin for staining cardiac fibrotic tissues. Although the extent of WFA staining was highly correlated (r > 0.98) with that of picrosirius red staining, a common collagen staining method, WFA did not bind to collagen fibers. Further histochemical analysis with N-glycosidase revealed that WFA staining of fibrotic tissues was attributable to the binding of WFA to N-glycoproteins. Using a mass spectrometry-based approach, we identified WFA-binding N-glycoproteins expressed in DCM hearts, many of which were fibrogenesis-related ECM proteins, as expected. In addition, the identified glycoproteins carrying WFA-binding N-glycans were detected only in DCM hearts, suggesting their cooperative glycosylation alterations with disease progression. Among these WFA-binding ECM N-glycoproteins, co-localization of the collagen α6(VI) chain protein and WFA staining in cardiac tissue sections was confirmed with a double-staining analysis. Collectively, these results indicate that WFA staining is more suitable for the quantitative assessment of cardiac fibrogenic activity than current collagen staining methods. Furthermore, given that plasma WFA-binding glycoprotein levels were significantly correlated with the echocardiographic parameters for left ventricular remodeling, cardiac WFA-binding glycoproteins are candidate circulating glyco-biomarkers for the quantification and monitoring of cardiac fibrogenesis.

Relationships between left ventricular geometry and remodeling in dilated cardiomyopathy

BACKGROUND

Since left ventricular reverse remodeling (LVRR) and sphericity index (SI) are correlated with DCM patients' survival, we attempted to establish the relationship between LVRR, SI and left ventricle (LV) dimensions.

METHODS

In 70 DCM patients, we measured EF, LV transverse (sLVd) and longitudinal (lLVd) diameters at hospital admission, then after 3 and 12 months. SI was assessed thus: SI=sLVd/lLVd.

RESULTS

LVRR was present in 32 patients (52%). SI measurements were similar in LVRR-present and -absent groups at baseline (0.71 vs. 0.70) and differed after 3 and 12 months (0.61 vs. 0.72, P<0.005; 0.59 vs. 0.73, P<0.001; respectively). During 12 months, SI and sLVd decreased in the LVRR-present (0.71 vs. 0.61 vs. 0.59, P<0.05; 5.75 vs. 5.00 vs. 4.82 cm, P<0.001; respectively) and increased in the LVRR-absent cohort (0.70 vs. 0.72 vs. 0.73, P<0.001; 6.01 vs. 6.15 vs. 6.67, P<0.001; respectively). lLVd remained stable (8.23 vs. 8.16 vs. 8.38cm; 8.66 vs. 8.85 vs. 9.13 cm; respectively). SI was significantly correlated with sLVd but not with lLVd. At 3-month follow-up, SI (P<0.005, OR=14000 [95% CI: 5 - 3.9*107]) was found to be a significant LVRR predictor via univariate logistic regression.

CONCLUSIONS

To summarize, changes in sLVd are crucial for changes in LV geometry, whereas lLVd has a negligible effect on this process. The presence of LVRR was not always associated with an improvement in SI and its absence with increase in SI. Since the assessment of SI is less complex than LVRR, SI as a significant LVRR predictor can be useful part of a regular echocardiography examination.