Dronedarone for the Treatment of Atrial Arrhythmias in Adults With Congenital Heart Disease.

BACKGROUND: Atrial tachyarrhythmias are common and difficult to treat in adults with congenital heart disease. Dronedarone has proven effective in patients without congenital heart disease, but data are limited about its use in adults with congenital heart disease of moderate to great complexity. METHODS: A single-center, retrospective chart review of 21 adults with congenital heart disease of moderate to great complexity who were treated with dronedarone for atrial tachyarrhythmias was performed. RESULTS: The median (IQR) age at dronedarone initiation was 35 (27.5-39) years. Eleven patients (52%) were male. Ten patients (48%) had New York Heart Association class I disease, 10 (48%) had class II disease, and 1 (5%) had class III disease. Ejection fraction at initiation was greater than 55% in 11 patients (52%), 35% to 55% in 9 patients (43%), and less than 35% in 1 patient (5%). Prior treatments included ß-blockers (71%), sotalol (38%), amiodarone (24%), digoxin (24%), and catheter ablation (38%). Rhythm control was complete in 5 patients (24%), partial in 6 (29%), and inadequate in 10 (48%). Two patients (10%) experienced adverse events, including nausea in 1 (5%) and cardiac arrest in 1 (5%), which occurred 48 months after initiation of treatment. There were no deaths during the follow-up period. The median (IQR) follow-up time for patients with complete or partial rhythm control was 20 (1-54) months. CONCLUSION: Dronedarone can be effective for adult patients with congenital heart disease and atrial arrhythmias for whom more established therapies have failed, and with close monitoring it can be safely tolerated.

Non-Invasive Radiofrequency Field Treatment of 4T1 Breast Tumors Induces T-cell Dependent Inflammatory Response.

Previous work using non-invasive radiofrequency field treatment (RFT) in cancer has demonstrated its therapeutic potential as it can increase intratumoral blood perfusion, localization of intravenously delivered drugs, and promote a hyperthermic intratumoral state. Despite the well-known immunologic benefits that febrile hyperthermia can induce, an investigation of how RFT could modulate the intra-tumoral immune microenvironment had not been studied. Thus, using an established 4T1 breast cancer model in immune competent mice, we demonstrate that RFT induces a transient, localized, and T-cell dependent intratumoral inflammatory response. More specifically we show that multi- and singlet-dose RFT promote an increase in tumor volume in immune competent Balb/c mice, which does not occur in athymic nude models. Further leukocyte subset analysis at 24, 48, and 120 hours after a single RFT show a rapid increase in tumoral trafficking of CD4+ and CD8+ T-cells 24 hours post-treatment. Additional serum cytokine analysis reveals an increase in numerous pro-inflammatory cytokines and chemokines associated with enhanced T-cell trafficking. Overall, these data demonstrate that non-invasive RFT could be an effective immunomodulatory strategy in solid tumors, especially for enhancing the tumoral trafficking of lymphocytes, which is currently a major hindrance of numerous cancer immunotherapeutic strategies.

Chemotherapy and Radiofrequency-Induced Mild Hyperthermia Combined Treatment of Orthotopic Pancreatic Ductal Adenocarcinoma Xenografts.

Patients with pancreatic ductal adenocarcinomas (PDAC) have one of the poorest survival rates of all cancers. The main reason for this is related to the unique tumor stroma and poor vascularization of PDAC. As a consequence, chemotherapeutic drugs, such as nab-paclitaxel and gemcitabine, cannot efficiently penetrate into the tumor tissue. Non-invasive radiofrequency (RF) mild hyperthermia treatment was proposed as a synergistic therapy to enhance drug uptake into the tumor by increasing tumor vascular inflow and perfusion, thus, increasing the effect of chemotherapy. RF-induced hyperthermia is a safer and non-invasive technique of tumor heating compared to conventional contact heating procedures. In this study, we investigated the short- and long-term effects (~20 days and 65 days, respectively) of combination chemotherapy and RF hyperthermia in an orthotopic PDAC model in mice. The benefit of nab-paclitaxel and gemcitabine treatment was confirmed in mice; however, the effect of treatment was statistically insignificant in comparison to saline treated mice during long-term observation. The benefit of RF was minimal in the short-term and completely insignificant during long-term observation.

Ultrasound Doppler as an Imaging Modality for Selection of Murine 4T1 Breast Tumors for Combination Radiofrequency Hyperthermia and Chemotherapy.

Noninvasive radiofrequency-induced (RF) hyperthermia has been shown to increase the perfusion of chemotherapeutics and nanomaterials through cancer tissue in ectopic and orthotopic murine tumor models. Additionally, mild hyperthermia (37°C-45°C) has previously shown a synergistic anticancer effect when used with standard-of-care chemotherapeutics such as gemcitabine and Abraxane. However, RF hyperthermia treatment schedules remain unoptimized, and the mechanisms of action of hyperthermia and how they change when treating various tumor phenotypes are poorly understood. Therefore, pretreatment screening of tumor phenotypes to identify key tumors that are predicted to respond more favorably to hyperthermia will provide useful mechanistic data and may improve therapeutic outcomes. Herein, we identify key biophysical tumor characteristics in order to predict the outcome of combinational RF and chemotherapy treatment. We demonstrate that ultrasound imaging using Doppler mode can be utilized to predict the response of combinational RF and chemotherapeutic therapy in a murine 4T1 breast cancer model.