Myocardial Fibrosis in Dilated Cardiomyopathy: Moving From Stratifying Risk to Improving Outcomes

Abstinence Restores Cardiac Function in Mice with Established Alcohol-Induced Cardiomyopathy

Alcohol-induced cardiomyopathy (ACM) has a poor prognosis with up to a 50% chance of death within four years of diagnosis. There are limited studies investigating the potential of abstinence for promoting repair after alcohol-induced cardiac damage, particularly in a controlled preclinical study design. Here, we developed an exposure protocol that led to significant decreases in cardiac function in C57BL6/J mice within 30 days; dP/dt max decreased in the mice fed alcohol for 30 days (8054 ± 664.5 mmHg/s compared to control mice: 11,188 ± 724.2 mmHg/s, p < 0.01), and the dP/dt min decreased, as well (-7711 ± 561 mmHg/s compared to control mice: -10,147 ± 448.2 mmHg/s, p < 0.01). Quantitative PCR was used to investigate inflammatory and fibrotic biomarkers, while histology was used to depict overt changes in cardiac fibrosis. We observed a complete recovery of function after abstinence (dP/dt max increased from 8054 ± 664 mmHg/s at 30 days to 11,967 ± 449 mmHg/s after abstinence, p < 0.01); further, both inflammatory and fibrotic biomarkers decreased after abstinence. These results lay the groundwork for future investigation of the molecular mechanisms underlying recovery from alcohol-induced damage in the heart.

Your Heart Function Has Normalized-What Next After TRED-HF?

PURPOSE OF REVIEW

With the widespread implementation of contemporary disease-modifying heart failure therapy, the rates of normalization of ejection fraction are continuously increasing. The TRED-HF trial confirmed that heart failure remission rather than complete recovery is typical in patients with dilated cardiomyopathy who respond to therapy. The present review outlines key points related to the management and knowledge gaps of this growing patient group, focusing on patients with non-ischaemic dilated cardiomyopathy.

RECENT FINDINGS

There is substantial heterogeneity among patients with normalized ejection fraction. The specific etiology is likely to affect the outcome, although a multiple-hit phenotype is frequent and may not be identified without comprehensive characterization. A monogenic or polygenic genetic susceptibility is common. Ongoing pathophysiological processes may be unraveled with advanced cardiac imaging, biomarkers, multi-omics, and machine learning technologies. There are limited studies that have investigated the withdrawal of specific heart failure therapies in these patients. Diuretics may be safely withdrawn if there is no evidence of congestion, while continued therapy with at least some disease-modifying therapy is likely to be required to reduce myocardial workload and sustain remission for the vast majority. Understanding the underlying disease mechanisms of patients with normalized ejection fraction is crucial in identifying markers of myocardial relapse and guiding individualized therapy in the future. Ongoing clinical trials should inform personalized approaches to therapy.

Cardiological Challenges Related to Long-Term Mechanical Circulatory Support for Advanced Heart Failure in Patients with Chronic Non-Ischemic Cardiomyopathy

Long-term mechanical circulatory support by a left ventricular assist device (LVAD), with or without an additional temporary or long-term right ventricular (RV) support, is a life-saving therapy for advanced heart failure (HF) refractory to pharmacological treatment, as well as for both device and surgical optimization therapies. In patients with chronic non-ischemic cardiomyopathy (NICM), timely prediction of HF's transition into its end stage, necessitating life-saving heart transplantation or long-term VAD support (as a bridge-to-transplantation or destination therapy), remains particularly challenging, given the wide range of possible etiologies, pathophysiological features, and clinical presentations of NICM. Decision-making between the necessity of an LVAD or a biventricular assist device (BVAD) is crucial because both unnecessary use of a BVAD and irreversible right ventricular (RV) failure after LVAD implantation can seriously impair patient outcomes. The pre-operative or, at the latest, intraoperative prediction of RV function after LVAD implantation is reliably possible, but necessitates integrative evaluations of many different echocardiographic, hemodynamic, clinical, and laboratory parameters. VADs create favorable conditions for the reversal of structural and functional cardiac alterations not only in acute forms of HF, but also in chronic HF. Although full cardiac recovery is rather unusual in VAD recipients with pre-implant chronic HF, the search for myocardial reverse remodelling and functional improvement is worthwhile because, for sufficiently recovered patients, weaning from VADs has proved to be feasible and capable of providing survival benefits and better quality of life even if recovery remains incomplete. This review article aimed to provide an updated theoretical and practical background for those engaged in this highly demanding and still current topic due to the continuous technical progress in the optimization of long-term VADs, as well as due to the new challenges which have emerged in conjunction with the proof of a possible myocardial recovery during long-term ventricular support up to levels which allow successful device explantation.

Visualization of fibroblast activation using 68Ga-FAPI PET/CT after pulmonary vein isolation with pulsed field compared with cryoballoon ablation

BACKGROUND

Pulsed-field ablation (PFA) is a novel ablation modality for atrial fibrillation (AF) ablating myocardium by electroporation without tissue-heating. With its different mechanism of tissue ablation, it is assumed that lesion creation is divergent to thermal energy sources. 68Ga-fibroblast-activation protein inhibitor (FAPI) PET/CT targets FAP-alpha expressed by activated fibroblasts. We aimed to assess 68Ga-FAPI uptake in pulmonary veins as surrogate for ablation damage after PFA and cryoballoon ablation (CBA).

METHODS

26 patients (15 PFA, 11 CBA) underwent 68Ga-FAPI-PET/CT after ablation. Standardized uptake values (SUV) and fibroblast-activation volumes of localized tracer uptake were assessed.

RESULTS

Patient characteristics were comparable between groups. In PFA, focal FAPI uptake was only observed in 3/15 (20%) patients, whereas in the CBA cohort, 10/11 (90.9%) patients showed atrial visual uptake. We observed lower values of SUVmax (2.85 ± 0.56 vs 4.71 ± 2.06, P = 0.025) and FAV (1.13 ± 0.84 cm3 vs 3.91 ± 2.74 cm3, P = 0.014) along with a trend towards lower SUVpeak and SUVmean in PFA vs CBA patients, respectively.

CONCLUSION

Tissue response with respect to fibroblast activation seems to be less pronounced in PFA compared to established thermal ablation systems. This functional assessment might contribute to a better understanding of lesion formation in thermal and PFA ablation potentially contributing to better safety outcomes.

A Mouse Model of Dilated Cardiomyopathy Produced by Isoproterenol Acute Exposure Followed by 5-Fluorouracil Administration

Appropriate dilated cardiomyopathy (DCM) animal models are highly desirable considering the pathophysiological and clinical heterogeneity of DCM. Genetically modified mice are the most widely and intensively utilized research animals for DCM. However, to translate discoveries from basic science into new and personalized medical applications, research in non-genetically based DCM models remains a key issue. Here, we characterized a mouse model of non-ischemic DCM induced by a stepwise pharmacologic regime of Isoproterenol (ISO) high dose bolus followed by a low dose systemic injection of the chemotherapy agent, 5-Fluorouracil (5-FU). C57BL/6J mice were injected with ISO and, 3 days after, were randomly assigned to saline or 5-FU. Echocardiography and a strain analysis show that ISO + 5FU in mice induces progressive left ventricular (LV) dilation and reduced systolic function, along with diastolic dysfunction and a persistent global cardiac contractility depression through 56 days. While mice treated with ISO alone recover anatomically and functionally, ISO + 5-FU causes persistent cardiomyocyte death, ensuing in cardiomyocyte hypertrophy through 56 days. ISO + 5-FU-dependent damage was accompanied by significant myocardial disarray and fibrosis along with exaggerated oxidative stress, tissue inflammation and premature cell senescence accumulation. In conclusions, a combination of ISO + 5FU produces anatomical, histological and functional cardiac alterations typical of DCM, representing a widely available, affordable, and reproducible mouse model of this cardiomyopathy.

Efficacy and Safety of Qili Qiangxin Capsule on Dilated Cardiomyopathy: A Systematic Review and Meta-Analysis of 35 Randomized Controlled Trials

Objective: Qili Qiangxin Capsule (QQC), a Chinese patent medicine, is clinically effective in treating dilated cardiomyopathy (DCM). However, the meta-analysis of QCC combined with conventional western medicine (CWM) on DCM remains unexplored. This study aimed to systematically evaluate the efficacy and safety of QCC in the treatment of DCM.

Methods: Searched the studies of the combination of QQC and CWM in the treatment of DCM, from databases like PubMed, Cochrane Library, Web of Science, Wan Fang Databases, Chinese Biomedical Literature Database, China Science and Technology Journal Database, China National Knowledge Infrastructure, prior to 15 January 2022. Two reviewers respectively regulated research selection, data extraction, and risk of bias assessment. Review Manager Software 5.4 was used for meta-analysis. Furthermore, GRADE pro3.6.1 software was selected to grade the current evidence in our findings. This meta-analysis has been registered in PROSPERO (CRD42022297906).

Results: There were 35 studies pertaining to 3,334 patients included. The meta-analysis showed compared with CWM alone, the combination therapy had significant advantages in improving the clinical efficiency rate (RR = 1.24, 95% CI: 1.19 to 1.29, p < 0.00001), 6 min walking distance (6MWD) (MD = 41.93, 95%CI: 39.82 to 44.04, p < 0.00001), superior in ameliorating the left ventricular ejection fraction (LVEF) (MD = 5.73, 95%CI: 4.70 to 6.77, p < 0.00001), left ventricular end-diastolic dimension (LVEDD) (MD = −4.09, 95%CI: −4.91 to −3.27), p < 0.00001), left ventricular end-systolic diameter (LVESD) (MD = −4.73, 95%CI: −5.63 to −3.84), p < 0.00001) and BNP (MD = −101.09, 95%CI: -132.99 to −69.18), p < 0.00001), and also superior in reducing hypersensitive-C-Reactive Protein (hs-CRP) (MD = −3.78, 95%CI: −4.35 to −3.21), p < 0.00001), Interleukin- 6 (IL-6) (MD = −25.92, 95%CI: −31.35 to -20.50), p < 0.00001), tumor necrosis factor-α (TNF-α) (MD = -5.04, 95%CI: −6.13 to −3.95), p < 0.00001), high mobility group protein B1 (HMGB1) (MD = −4.34, 95%CI: −5.22 to −3.46), p < 0.00001), and adverse reactions (ARs) (RR = 0.70, 95%CI: 0.51–0.97), p = 0.03). The GRADE evidence quality rating presented with moderate or low quality of evidence for the available data.

Conclusion: Compared with the control group, QQC combined with CWM may be effective in treating DCM. However, the conclusion of this study must be interpreted carefully due to the inferior quality and ambiguity of bias in the included trials.

Systematic Review Registration: https://www.crd.york.ac.uk/prospero, identifier [CRD42022297906].