Relationship between diffuse fibrosis assessed by CMR and depressed myocardial strain in different stages of heart failure

Computer-Assisted Algorithm for Quantification of Fibrosis by Native Cardiac CT: A Pilot Study

Background/Objectives: Recent advances in artificial intelligence, particularly in cardiac imaging, can potentially enhance patients' diagnosis and prognosis and identify novel imaging markers. We propose an automated, computer-aided algorithm utilizing native cardiac computed tomography (CT) imaging to identify myocardial fibrosis. This study aims to evaluate its performance compared to CMR markers of fibrosis in a cohort of patients diagnosed with breast cancer. Methods: The study included patients diagnosed with early HER2+ breast cancer, who presented LV dysfunction (LVEF < 50%) and myocardial fibrosis detected on CMR at the time of diagnosis. The patients were also evaluated by cardiac CT, and the extracted images were processed for the implementation of the automatic, computer-assisted algorithm, which marked as fibrosis every pixel that fell within the range of 60-90 HU. The percentage of pixels with fibrosis was subsequently compared with CMR parameters. Results: A total of eight patients (n = 8) were included in the study. High positive correlations between the algorithm's result and the ECV fraction (r = 0.59, p = 0.126) and native T1 (r = 0.6, p = 0.112) were observed, and a very high positive correlation with LGE of the LV(g) and the LV-LGE/LV mass percentage (r = 0.77, p = 0.025; r = 0.81, p = 0.015). A very high negative correlation was found with GLS (r = -0.77, p = 0.026). The algorithm presented an intraclass correlation coefficient of 1 (95% CI 0.99-1), p < 0.001. Conclusions: The present pilot study proposes a novel promising imaging marker for myocardial fibrosis, generated by an automatic algorithm based on native cardiac CT images.

Collagen Triple Helix Repeat-Containing Protein 1 Is a Novel Biomarker of Right Ventricular Involvement in Pulmonary Hypertension

BACKGROUND

Pulmonary hypertension leads to right ventricular failure, which is a major determinant of prognosis. Circulating biomarkers for right ventricular function are poorly explored in pulmonary hypertension. This study aimed to clarify the significance of collagen triple helix repeat-containing protein 1 (CTHRC1) as a biomarker of right ventricular failure in pulmonary hypertension.

METHODS

A monocrotaline-induced pulmonary hypertension rat model was used to evaluate right ventricular CTHRC1 expression and its relationship with fibrosis. Next, human plasma CTHRC1 levels were measured in controls (n = 20), pulmonary arterial hypertension (n = 46), and patients with chronic thromboembolic pulmonary hypertension (CTEPH) (n = 64) before the first and after the final balloon pulmonary angioplasty.

RESULTS

CTHRC1 expression was higher in the right ventricles of rats with monocrotaline-induced pulmonary hypertension than in those of controls. CTHRC1 was colocalized with vimentin and associated with fibrosis in the right ventricles. Plasma CTHRC1 levels were higher in human patients with pulmonary arterial hypertension (P = 0.006) and CTEPH (P = 0.011) than in controls. Plasma CTHRC levels were correlated with B-type natriuretic peptide (R = 0.355, P < 0.001), tricuspid lateral annular peak systolic velocity (R = -0.213, P = 0.029), and right ventricular fractional area change (R = -0.225, P = 0.017). Finally, plasma CTHRC1 levels were decreased after the final balloon pulmonary angioplasty (P < 0.001) in CTEPH.

CONCLUSIONS

CTHRC1 can be a circulating biomarker associated with right ventricular function and fibrosis in pulmonary hypertension and might reflect the therapeutic efficacy of balloon pulmonary angioplasty in CTEPH.

Distinguishing heart failure subtypes: the diagnostic power of different cardiac magnetic resonance imaging parameters

Objectives

The aim of this retrospective study was to explore the diagnostic potential of various cardiac parameters in differentiating between heart failure with preserved ejection fraction (HFpEF) and heart failure with mid-ranged and reduced ejection fraction (HFm + rEF), and to discern their relationship with normal cardiac function.

Methods

This research encompassed a comparative analysis of heart failure subtypes based on multiple indicators. Participants were categorized into HFm + rEF, HFpEF, and control groups. For each participant, we investigated indicators of left ventricular function (LVEDVi, LVESVi, and LVEF) and myocardial strain parameters (GLS, GCS, GRS). Additionally, quantitative tissue evaluation parameters including native T1, enhanced T1, and extracellular volume (ECV) were examined.For comprehensive diagnostic performance analysis, receiver operating characteristic (ROC) curve evaluations for each parameters were conducted.

Results

HFm + rEF patients exhibited elevated LVEDVi and LVESVi and decreased LVEF compared to both HFpEF and control groups. Myocardial strain revealed significant reductions in GLS, GCS, and GRS for HFm + rEF patients compared to the other groups. HFpEF patients showed strain reductions relative to the control group. In cardiac magnetic resonance imaging (CMR) evaluations, HFm + rEF patients demonstrated heightened native T1 times and ECV fractions. Native T1 was particularly effective in distinguishing HFpEF from healthy subjects.

Conclusion

Native T1, ECV, and myocardial strain parameters have substantial diagnostic value in identifying HFpEF. Among them, native T1 displayed superior diagnostic efficiency relative to ECV, offering critical insights into early-stage HFpEF. These findings can play a pivotal role in refining clinical management and treatment strategies for heart failure patients.