Cancer Chemotherapy-Induced Sinus Bradycardia: A Narrative Review of a Forgotten Adverse Effect of Cardiotoxicity

Fludarabine-induced bradycardia in allogeneic hematopoietic stem cell transplantation: A retrospective study

INTRODUCTION

Fludarabine, a purine analog, is getting more attention with the increasing use of reduced intensive conditioning regimens in allogeneic hematopoietic stem cell transplantation (allo-HSCT). The side effect of bradycardia was observed in only a few cases reported in the literature. In clinical practice, bradycardia can be asymptomatic or cause syncope and cardiac arrest. This study aimed to evaluate the bradycardia side effect of fludarabine used in the conditioning regimen in allo-HSCT recipients and to increase awareness of this issue.

METHODS

This retrospective study included 73 patients who received fludarabine in the allo-HSCT conditioning regimen between January 2015 and January 2021. Patients with and without bradycardia were compared regarding demographic data, allo-HSCT characteristics, electrolyte values, fludarabine administration dose and duration, and survival. Univariate and multivariate analyzes were performed to evaluate independent predictors for fludarabine-induced bradycardia.

RESULTS

Fludarabine administration doses and days were higher in the bradycardia group, but no statistically significant difference was observed. In the multivariate analysis, age was the only independent predictor of fludarabine-induced bradycardia (odds ratio (OR) 0.93, 95% confidence interval (CI): 0.89-0.98, p = 0.007). The median age in the group with bradycardia was 19 years younger than those without bradycardia (34 (19-49) vs 53 (19-69), p = 0.005). In 11 (84.6%) of the patients who had bradycardia, bradycardia improved with the discontinuation of fludarabine alone, but atropine was administered in 2 (15.4%) patients.

CONCLUSION

Age was the only independent predictor of fludarabine-induced bradycardia; therefore, close heart rate monitoring is recommended during fludarabine administration, especially in younger patients.

Untargeted metabolic profiling of high-dose methotrexate toxicity shows alteration in betaine metabolism

Cardiotoxicity is a well-established adverse effect of several drugs across multiple therapeutic indications. It is particularly prevalent following anticancer therapy. In order to evaluate the changes in cellular metabolism associated with methotrexate cardiotoxicity, we treated Wistar rats with a single high dose of methotrexate (HDMTX), and after five days, the animals were sacrificed. We then analyzed the cardiotoxicity parameters in serum like Cardiac enzymes(CK-MB, Troponin T, ALP), Inflammatory markers (TNF-α and IL-6), oxidative stress markers (NO, NOX-2), histopathology and cardiac tissue with the goal of identifying a metabolic signature of cardiotoxicity using discovery-based metabolomics. The biochemical parameters for cardiac enzymes, oxidative stress and inflammatory markers showed a significant increase in all three categories in rats treated with HDMTX. These findings were mirrored in the histopathological analysis confirming cardiotoxicity due to HDMTX. The results showed a total of 95 metabolites that were found to be significantly (p < 0.05) modulated: either up- or downregulated in the HDMTX-treated group when compared with the control group. Using integrated pathway analysis we found these metabolites were associated with many important cardiac tissue metabolic pathways, such as the malate aspartate shuttle, taurine and hypotaurine metabolism, betaine metabolism, spermidine biosynthesis, and homocysteine degradation. Among them, L-arginine, homocysteine, and betaine were significantly upregulated, suggesting their possible association with cardiac tissue injury. Overall, we provided evidence for using untargeted metabolomics to identify novel metabolites associated with HDMTX cardiac toxicity.

Azilsartan improves doxorubicin-induced cardiotoxicity via inhibiting oxidative stress, proinflammatory pathway, and apoptosis

Azilsartan, a known angiotensin receptor blocker, has shown potential in reducing 24-hour blood pressure and may have protective effects against cardiac complications. Increased oxidative stress in cardiac tissue is directly related to the cardiac complications of doxorubicin. This study investigated whether azilsartan could mitigate doxorubicin-induced cardiotoxicity. We divided 28 male rats into four groups: the control group receiving a standard diet and water, the vehicle group given DMSO orally for two weeks, doxorubicin group receiving 2.5 mg/kg of doxorubicin three times a week for two weeks, and azilsartan group treated with 5 mg/kg/day of azilsartan orally and doxorubicin. Doxorubicin-induced cardiotoxicity was evidenced by a significant increase in TNF-α, IL-1β, MDA, and caspase-3 levels and significantly decreased TAC and Bcl-2 levels in the cardiac tissues of treated rats compared to the DMSO and control groups. Azilsartan significantly decreased doxorubicin-induced cardiotoxicity, as evidenced by a decline in serum levels of both TNF-α and IL-1β. Additionally, MDA significantly decreased in the cardiac tissue, although TAC was significantly increased when comparing the azilsartan group to the group receiving doxorubicin-only. These results suggest that azilsartan effectively reduced doxorubicin-induced cardiotoxicity, likely by mitigating apoptosis, inflammation, and oxidative stress in cardiac tissues.

Multimodality imaging in cardio-oncology: the added value of CMR and CCTA

During the last 30 years, we have assisted to a great implementation in anticancer treatment with a subsequent increase of cancer survivors and decreased mortality. This has led to an ongoing interest about the possible therapy-related side-effects and their management to better guide patients therapy and surveillance in the chronic and long-term setting. As a consequence cardio-oncology was born, involving several different specialties, among which radiology plays a relevant role. Till the end of August 2022, when European Society of Cardiology (ESC) developed the first guidelines on cardio-oncology, no general indications existed to guide diagnosis and treatment of cancer therapy-related cardiovascular toxicity (CTR-CVT). They defined multimodality imaging role in primary and secondary prevention strategies, cancer treatment surveillance and early CTR-CVT identification and management. Cardiac computed tomography angiography (CCTA) has acquired a central role in coronary assessment, as far as coronary artery disease (CAD) exclusion is concerned; but on the side of this well-known application, it also started to be considered in left ventricular function evaluation, interstitial fibrosis quantification and cardiac perfusion studies. Cardiac magnetic resonance (CMR), instead, has been acknowledged as the gold standard alternative to trans-thoracic echocardiography (TTE) poor acoustic window in quantification of heart function and strain modifications, as well as pre- and post-contrast tissue characterization by means of T1-T2 mapping, early Gadolinium enhancement (EGE), late Gadolinium enhancement (LGE) and extracellular volume (ECV) evaluation. Our review is intended to provide a focus on the actual role of CMR and CCTA in the setting of a better understanding of cardiotoxicity and to draw some possible future directions of cardiac imaging in this field, starting from the recently published ESC guidelines.

Prediction Performance of Deep Learning for Colon Cancer Survival Prediction on SEER Data

Colon and rectal cancers are the most common kinds of cancer globally. Colon cancer is more prevalent in men than in women. Early detection increases the likelihood of survival, and treatment significantly increases the likelihood of eradicating the disease. The Surveillance, Epidemiology, and End Results (SEER) programme is an excellent source of domestic cancer statistics. SEER includes nearly 30% of the United States population, covering various races and geographic locations. The data are made public via the SEER website when a SEER limited-use data agreement form is submitted and approved. We investigate data from the SEER programme, specifically colon cancer statistics, in this study. Our objective is to create reliable colon cancer survival and conditional survival prediction algorithms. In this study, we have presented an overview of cancer diagnosis methods and the treatments used to cure cancer. This paper presents an analysis of prediction performance of multiple deep learning approaches. The performance of multiple deep learning models is thoroughly examined to discover which algorithm surpasses the others, followed by an investigation of the network's prediction accuracy. The simulation outcomes indicate that automated prediction models can predict colon cancer patient survival. Deep autoencoders displayed the best performance outcomes attaining 97% accuracy and 95% area under curve-receiver operating characteristic (AUC-ROC).

Discovery of 1,3,4-oxadiazole derivatives containing a bisamide moiety as a novel class of potential cardioprotective agents

Myocardial injury is a nonnegligible problem in cardiovascular diseases and cancer therapy. The functional feature of N-containing heterocycles in the cardiovascular field has attracted much attention in recent years. Herein, we discovered a lead compound 12a containing 1,3,4-oxadiazole by extensive screening of anticancer derivatives containing nitrogen-heterocycle, which exhibited potential protective activity against oxidative stress in cardiomyocytes. Follow-up structure-activity relationship (SAR) studies also highlighted the role of substitution sites and bisamide moiety in enhancing the protective activity against oxidative stress. Specifically, compound 12d exhibited low cytotoxicity under high concentration and potent myocardial protection against oxidative stress in H9c2 cells. Preliminary mechanistic studies showed compound 12d could decrease the expression of cardiac hypertrophy and oxidative stress-related proteins/genes and reduce mitochondria-mediated cell apoptosis, thereby enhancing the cell vitality of injured cardiomyocytes. In this study, 1,3,4-oxadiazole may represent a novel pharmacophore that possesses potential myocardial protection and provides more choices for future optimization of cardiovascular drugs, especially for the treatment of onco-cardiology.