Right Atrial Epidermoid Cyst: An Unusual Mass Discovered in the Workup for Arrhythmia in Pregnancy

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Cardiac heterotopia (noncardiac tissue in the heart) is a rare condition.

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It is thought to be related to disrupted cell migration during development.

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Cardiac heterotopia can give rises to masses that present with symptoms decades later.

Usefulness of Long-Term Anticoagulation After Catheter Ablation of Atrial Fibrillation

Although atrial fibrillation (AF) is strongly associated with stroke, previous studies have shown suboptimal use of anticoagulation (AC). In particular, there is a lack of data on the long-term use of AC after AF catheter ablation. We followed up patients 1 to 5 years out from catheter ablation at the Johns Hopkins Hospital (JHH) to assess their long-term use of AC. We sent a survey to patients from the JHH AF database who underwent an AF catheter ablation between 01/01/2014 and 03/31/2018. Patients were asked whether they were still on AC, if they thought the ablation was successful in controlling AF symptoms and whether they had follow-up rhythm monitoring. Replies were compared with risk scores and demographic data from the electronic medical record. We sent the survey to 628 patients in the database meeting our inclusion criteria, and we received 289 responses. The average age of patients was 67 ± 10 with a median CHA₂DS₂-VASc of 2 and a median follow-up of 3.6 years. Overall, 81.6% of patients with a CHA₂DS₂-VASc >2 reported taking AC. Use of AC was positively correlated with a higher CHA₂DS₂-VASc score (p = 0.012) and older age (p = 0.028), but negatively correlated with a successful ablation (p = 0.040). The most common reason (50.0%) for not being on AC was that doctors were recommending stopping it after a successful ablation. In general, higher risk patients (older, higher CHA₂DS₂-VASC score) were more likely to remain on AC. However, patients who self-reported a successful ablation were less likely to remain on AC. There may be many patients who can tolerate AC, but are recommended to stop due to a successful ablation. It is still debated how successful AF ablation affects stroke risk. In conclusion, there is considerable variation in the long-term management of AC after an ablation, but for the present, it seems prudent to continue AC based on stroke risk scores until more definite data are available.

Wavefront Field Mapping Reveals a Physiologic Network Between Drivers Where Ablation Terminates Atrial Fibrillation

BACKGROUND

Localized drivers are proposed mechanisms for persistent atrial fibrillation (AF) from optical mapping of human atria and clinical studies of AF, yet are controversial because drivers fluctuate and ablating them may not terminate AF. We used wavefront field mapping to test the hypothesis that AF drivers, if concurrent, may interact to produce fluctuating areas of control to explain their appearance/disappearance and acute impact of ablation.

METHODS

We recruited 54 patients from an international registry in whom persistent AF terminated by targeted ablation. Unipolar AF electrograms were analyzed from 64-pole baskets to reconstruct activation times, map propagation vectors each 20 ms, and create nonproprietary phase maps.

RESULTS

Each patient (63.6±8.5 years, 29.6% women) showed 4.0±2.1 spatially anchored rotational or focal sites in AF in 3 patterns. First, a single (type I; n=7) or, second, paired chiral-antichiral (type II; n=5) rotational drivers controlled most of the atrial area. Ablation of 1 to 2 large drivers terminated all cases of types I or II AF. Third, interaction of 3 to 5 drivers (type III; n=42) with changing areas of control. Targeted ablation at driver centers terminated AF and required more ablation in types III versus I (P=0.02 in left atrium).

CONCLUSIONS

Wavefront field mapping of persistent AF reveals a pathophysiologic network of a small number of spatially anchored rotational and focal sites, which interact, fluctuate, and control varying areas. Future work should define whether AF drivers that control larger atrial areas are attractive targets for ablation.

Comparing phase and electrographic flow mapping for persistent atrial fibrillation

BACKGROUND

An increasing number of methods are being used to map atrial fibrillation (AF), yet the sensitivity of identifying potential localized AF sources of these novel methods are unclear. Here, we report a comparison of two approaches to map AF based upon (1) electrographic flow mapping and (2) phase mapping in a multicenter registry of patients in whom ablation terminated persistent AF.

METHODS

Fifty-three consecutive patients with persistent AF in whom ablation terminated AF in an international multicenter registry were enrolled. Electrographic flow mapping (EGF) and phase mapping were applied to the multipolar simultaneous electrograms recorded from a 64-pole basket catheter in the chamber (left vs right atrium) where AF termination occurred. We analyzed if the mapping methods were able to detect localized sources at the AF termination site. We also analyzed global results of mapping AF for each method, patterns of activation of localized sources.

RESULTS

Patients were 64.3 ± 9.4 years old and 69.8% were male. EGF and phase mapping identified localized sources at AF termination sites in 81% and 83% of the patients, respectively. Methods were complementary and in only n = 2 (3.7%) neither method identified a source. Globally, EGF identified more localized sources than phase mapping (5.3 ± 2.8 vs 1.8 ± 0.5, P < 0.001), with a higher prevalence of focal (compared to rotational) activation pattern (49% vs 2%, P < 0.01).

CONCLUSIONS

EGF is a novel vectorial-based AF mapping method, which can detect sites of AF termination, agreeing with, and complementary to, an alternative AF mapping method using phase analysis.

Cancer-Associated Fibroblasts Drive Glycolysis in a Targetable Signaling Loop Implicated in Head and Neck Squamous Cell Carcinoma Progression

Despite aggressive therapies, head and neck squamous cell carcinoma (HNSCC) is associated with a less than 50% 5-year survival rate. Late-stage HNSCC frequently consists of up to 80% cancer-associated fibroblasts (CAF). We previously reported that CAF-secreted HGF facilitates HNSCC progression; however, very little is known about the role of CAFs in HNSCC metabolism. Here, we demonstrate that CAF-secreted HGF increases extracellular lactate levels in HNSCC via upregulation of glycolysis. CAF-secreted HGF induced basic FGF (bFGF) secretion from HNSCC. CAFs were more efficient than HNSCC in using lactate as a carbon source. HNSCC-secreted bFGF increased mitochondrial oxidative phosphorylation and HGF secretion from CAFs. Combined inhibition of c-Met and FGFR significantly inhibited CAF-induced HNSCC growth in vitro and in vivo (P < 0.001). Our cumulative findings underscore reciprocal signaling between CAF and HNSCC involving bFGF and HGF. This contributes to metabolic symbiosis and a targetable therapeutic axis involving c-Met and FGFR.Significance: HNSCC cancer cells and CAFs have a metabolic relationship where CAFs secrete HGF to induce a glycolytic switch in HNSCC cells and HNSCC cells secrete bFGF to promote lactate consumption by CAFs. Cancer Res; 78(14); 3769-82. ©2018 AACR.

Independent mapping methods reveal rotational activation near pulmonary veins where atrial fibrillation terminates before pulmonary vein isolation

OBJECTIVE

To investigate mechanisms by which atrial fibrillation (AF) may terminate during ablation near the pulmonary veins before the veins are isolated (PVI).

INTRODUCTION

It remains unstudied how AF may terminate during ablation before PVs are isolated, or how patients with PV reconnection can be arrhythmia-free. We studied patients in whom PV antral ablation terminated AF before PVI, using two independent mapping methods.

METHODS

We studied patients with AF referred for ablation, in whom biatrial contact basket electrograms were studied by both an activation/phase mapping method and by a second validated mapping method reported not to create false rotational activity.

RESULTS

In 22 patients (age 60.1 ± 10.4, 36% persistent AF), ablation at sites near the PVs terminated AF (77% to sinus rhythm) prior to PVI. AF propagation revealed rotational (n  =  20) and focal (n  =  2) patterns at sites of termination by mapping method 1 and method 2. Both methods showed organized sites that were spatially concordant (P < 0.001) with similar stability (P < 0.001). Vagal slowing was not observed at sites of AF termination.

DISCUSSION

PV antral regions where ablation terminated AF before PVI exhibited rotational and focal activation by two independent mapping methods. These data provide an alternative mechanism for the success of PVI, and may explain AF termination before PVI or lack of arrhythmias despite PV reconnection. Mapping such sites may enable targeted PV lesion sets and improved freedom from AF.

Abstract B37: Targeting tumor-stroma metabolic symbiosis for head and neck cancer therapy

Despite aggressive therapies, head and neck squamous cell carcinoma (HNSCC), which affects 50,000 new patients annually in the United States, is associated with less than 50% 5-year survival. HNSCC tumors display increased glycolysis, even in the presence of oxygen. Consequently, there is an increase in lactic acid (LA) production. However, the effect of lactic acid in the tumor microenvironment and the mechanisms whereby HNSCC tumors survive in highly acidic conditions remain unknown. HNSCC consist of up to 80% tumor-associated fibroblasts (TAFs). We previously reported that activation of receptor tyrosine kinase, c-Met, by TAF-secreted hepatocyte growth factor (HGF) contributes to HNSCC progression (1,2). The mechanism associated with tumor-stroma metabolic symbiosis is not well understood. On this basis, we hypothesized that TAF-secreted HGF regulates HNSCC glycolysis. We demonstrate that HNSCC-secreted basic fibroblast growth factor (bFGF) induces oxidative phosphorylation (OXPHOS) in TAFs. In addition, bFGF regulates secretion of HGF from TAFs. TAF-secreted HGF increases HNSCC glycolysis and induces bFGF secretion from HNSCC. Thus, HNSCC and TAFs engage in reciprocal signaling through paracrine effects of HGF and bFGF. Inhibition of c-Met with small molecule inhibitor PF-02341066 or specific knockdown with c-Met siRNA decreased TAF-facilitated HNSCC glycolysis, lactic acid production and bFGF expression. In addition, inhibition of FGFR with small molecule inhibitor AZD-4547 decreased OXPHOS and HGF expression in TAFs. Inhibition of FGFR also reduced HNSCC-stimulated phosphorylation of p42/44 mitogen activated protein kinase, proliferation and migration in TAFs. Further, we tested the efficacy of AZD-4547 in combination with c-Met inhibitor PF-02341066 in mitigating TAF-induced HNSCC growth in vitro and in vivo. Combined treatment with AZD-4547 and PF-02341066 significantly inhibited TAF-induced proliferation of HNSCC in vitro compared to the vehicle control treated cells (p&lt;0.001). Further, combined treatment significantly reduced growth of admixed HNSCC and TAF xenograft tumors (p&lt;0.001). Our cumulative findings underscore the therapeutic potential of combinatorial treatment with PF-02341066 and AZD-4547 in HNSCC. The therapeutic approach developed in this study may be a feasible in HNSCC.

1. Wheeler SE, Shi H, Lin F, Dasari S, Bednash J, Thorne S, et al. Enhancement of head and neck squamous cell carcinoma proliferation, invasion, and metastasis by tumor-associated fibroblasts in preclinical models. Head & neck 2014;36(3):385-92.

2. Knowles LM, Stabile LP, Egloff AM, Rothstein ME, Thomas SM, Gubish CT, et al. HGF and c-Met participate in paracrine tumorigenic pathways in head and neck squamous cell cancer. Clinical cancer research : an official journal of the American Association for Cancer Research 2009;15(11):3740-50.

Citation Format: Dhruv Kumar, Vikalp Vishwakarma, Jacob New, Wade Gutierrez, Hemant Chavan, Partha Kasturi, Ossama Tawfik, Douglas Girod, Bennett Van Houten, George Leef, Radhika Joshi, Shary Shelton, Jeffrey Straub, Yelizaveta Shnayder, Kiran Kakarala, Terance Tsue, Fangchen Lin, Sumana Dasari, Sufi Thomas. Targeting tumor-stroma metabolic symbiosis for head and neck cancer therapy. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr B37.

Abstract WP169: Racial Disparities n Risk of Stroke and Mortality Among Patients Undergoing Rhythm Control of Atrial Fibrillation

Introduction: Racial disparities in cardiovascular therapies and outcomes have been previously reported. We sought to investigate the risks of stroke and death in African American (AA) and white patients undergoing rhythm control of atrial fibrillation (AF).

Hypothesis: AA patients have greater risk of stroke and death compared to white patients.

Methods: We collected data on 5632 white and 241 AA patients that initiated rhythm control therapy for AF at our institution from 2006-2013. Cox proportional-hazards models were used to assess risk factors for stroke and mortality by race.

Results: Patients were followed for a median of 40 months (range 1-101). AA patients had higher risk of stroke (6.6% vs. 3.9%, p=0.01) and all-cause mortality (16.2% vs. 13.1%, p=0.03) than white patients. Multivariate modeling confirmed the higher risk of stroke (HR=1.98, 95% CI [1.18-3.31], p=0.01) and mortality (HR=1.49, 95% CI [1.04-2.06], p=0.02) in AA patients after adjusting for baseline differences between race groups (age, HTN, DM, heart failure, and chronic kidney disease). AA patients with DM had an especially high risk of stroke (see Figure).

Conclusions: African-American patients treated with a rhythm management strategy had significantly greater risk of stroke and all-cause mortality compared to white patients. AA patients with DM had an especially high risk, but the difference between AA patients vs. white patients was not explained by differences in baseline risk factors. Further investigation is required to determine the root causes of these racial disparities.

Mortality risk of long-term amiodarone therapy for atrial fibrillation patients without structural heart disease

BACKGROUND

Amiodarone is often prescribed in the management of atrial fibrillation (AF) but is known to cause significant end-organ toxicities. In this study, we examined the impact of amiodarone on all-cause mortality in AF patients with structurally normal hearts.

METHODS

We performed a retrospective cohort analysis of all AF patients with structurally normal hearts who were prescribed antiarrhythmic drugs (AAD) for rhythm control of AF at our institution from 2006 to 2013 (n = 2,077). Baseline differences between the amiodarone (AMIO: n = 403) and other AADs (NON-AMIO: n = 1,674) groups were corrected for using propensity score matching.

RESULTS

Amiodarone use as first-line therapy decreased significantly with a higher degree of prescriber specialization in arrhythmia management (31%, 22%, and 9% for primary care physicians, general cardiologists and cardiac electrophysiologists, respectively, p < 0.001). After propensity score matching, baseline comorbidities were balanced between the AMIO and NON-AMIO groups. Over a median follow-up of 28.2 months (range 6.0-100.9 months), amiodarone was associated with increased all-cause (HR 2.41, p = 0.012) and non-cardiac (HR 3.55, p = 0.008) mortality, but not cardiac mortality. AF recurrence and cardiac hospitalizations were similar between the two study groups.

CONCLUSIONS

Amiodarone treatment of AF is associated with increased mortality in patients without structural heart disease and therefore should be avoided or only used as a second-line therapy, when other AF therapies fail. Adherence to guideline recommendations in the management of AF patients impacts clinical outcome.

Comparative effectiveness of antiarrhythmic drugs for rhythm control of atrial fibrillation

INTRODUCTION

Although there are many different antiarrhythmic drugs (AADs) approved for rhythm management of atrial fibrillation (AF), little comparative effectiveness data exist to guide drug selection.

METHODS

We followed 5952 consecutive AF patients who were prescribed amiodarone (N=2266), dronedarone (N=488), dofetilide (N=539), sotalol (N=1718), or class 1C agents (N=941) to the primary end point of AF recurrence.

RESULTS

Median follow-up time was 18.2 months (range 0.1-101.6 months). Patients who were prescribed amiodarone had the highest, while patients on class 1C agents had the lowest baseline CHA2DS2-VASc score, Charlson comorbidity index, and burden of comorbid illnesses including coronary artery disease, congestive heart failure, diabetes mellitus, hyperlipidemia, chronic obstructive lung disease, chronic kidney disease, or cancer (p<0.05 for all comparisons). After adjusting for baseline characteristics, using dronedarone as benchmark, amiodarone [hazard ratio (HR) 0.58, p<0.001], class 1C agents (HR 0.70, p<0.001), and sotalol (HR 0.79, p=0.008), but not dofetilide (HR 0.87, p=0.178) were associated with less AF recurrence. In addition, compared to dronedarone, amiodarone and class 1C agents were associated with lower rates of admissions for AF (HR 0.55, p<0.001 for amiodarone; HR 0.71, p=0.021 for class 1C agents) and all-cause mortality was lowest in patients treated with class 1C agents (HR 0.42, p=0.018). The risk of stroke was similar among all groups.

CONCLUSION

Compared with dronedarone, amiodarone, class 1C agents, and sotalol are more effective for rhythm control, while dofetilide had similar efficacy. These findings have important implications for clinical practice.

Patient outcomes according to adherence to treatment guidelines for rhythm control of atrial fibrillation

Background

Although guidelines for antiarrhythmic drug therapy in atrial fibrillation (AF) were published in 2006, it remains uncertain whether adherence to these guidelines affects patient outcomes.

Methods and Results

We retrospectively evaluated the records of 5976 consecutive AF patients who were prescribed at least 1 antiarrhythmic drug between 2006 and 2013. Patients with 1 or more prescribed antiarrhythmic drugs that did not comply with guideline recommendations comprised the non–guideline‐directed group (=2920); the remainder constituted the guideline‐directed group (=3056). Time to events was assessed using the survival analysis method and adjusted for covariates using Cox regression. Rates of adherence to the guidelines increased significantly with a higher degree of prescriber specialization in arrhythmias (49%, 55%, and 60% for primary care physicians, general cardiologists, and cardiac electrophysiologists, respectively, P=0.001) for the first prescribed antiarrhythmic drug. Compared to the non–guideline‐directed group, the guideline‐directed group had higher rates of heart failure, but lower baseline CHADS2‐VASc scores (P<0.001) and lower rates of coronary artery disease, valvular disease, hypertension, hyperlipidemia, pulmonary disease, and renal insufficiency (P<0.05 for all). During 45±26 months follow‐up, the guideline‐directed group had a lower risk of AF recurrence (hazard ratio=0.86, 95% CI=0.80 to 0.93), fewer hospital admissions for AF (hazard ratio=0.87, 95% CI=0.79 to 0.97), and fewer procedures for recurrent AF, including electrical cardioversion, pacemaker implantation, and atrioventricular nodal ablation (P<0.01 for all). The mortality and stroke risks were similar between the groups.

Conclusions

Adherence to published guidelines in the antiarrhythmic management of AF is associated with improved patient outcomes.

Molecular communication between tumor-associated fibroblasts and head and neck squamous cell carcinoma

Over the past few decades, it has become increasingly clear that the lethality of cancers depends on more than the malignant cells themselves. The environment those malignant cells are exposed to is just as important a determinant of their behavior. Head and neck squamous cell carcinoma (HNSCC) is both common and deadly. It is the 6th most frequently occurring cancers, and prognosis is still generally poor. Recent evidence indicates that activated fibroblasts residing within the tumor stroma play a significant role in promoting the aggressive spread often seen in head and neck cancer. Tumor associated fibroblasts (TAFs) have also been implicated in facilitating angiogenesis and suppressing the normal anti-tumor function of immune cells. Studying the signaling molecules involved in these processes will facilitate the development of promising targets and inhibitors to prevent tumor-associated fibroblasts from exerting their reinforcing effects on the tumor. In this article, we review the recent literature on the signals used in tumor associated fibroblast communication, with a focus on potential therapeutic targets. Further, we highlight the lead candidates for TAF-targeted therapeutic interventions. Future anti-cancer strategies may achieve better results than current approaches by targeting the support cells in tumor stroma in addition to the cancerous cells.

Utility of 3'-[(18)F]fluoro-3'-deoxythymidine as a PET tracer to monitor response to gene therapy in a xenograft model of head and neck carcinoma

Noninvasive imaging methodologies are needed to assess treatment responses to novel molecular targeting approaches for the treatment of squamous cell carcinoma of the head and neck (SCCHN). Computer tomography and magnetic resonance imaging do not effectively distinguish tumors from fibrotic tissue commonly associated with SCCHN tumors. Positron emission tomography (PET) offers functional non-invasive imaging of tumors. We determined the uptake of the PET tracers 2-deoxy-2-[(18)F]fluoro-D-glucose ([(18)F]FDG) and 3'-[(18)F]Fluoro-3'-deoxythymidine ([(18)F]FLT) in several SCCHN xenograft models. In addition, we evaluated the utility of [(18)F]FLT microPET imaging in monitoring treatment response to an EGFR antisense approach targeted therapy that has shown safety and efficacy in a phase I trial. Two of the 3 SCCHN xenograft models tested demonstrated no appreciable uptake or retention of [(18)F]FDG, but consistent accumulation of [(18)F]FLT. The third tumor xenograft SCCHN model (Cal33) demonstrated variable uptake of both tracers. SCCHN xenografts (1483) treated with EGFR antisense gene therapy decreased tumor volumes in 4/6 mice. Reduced uptake of [(18)F]FLT was observed in tumors that responded to epidermal growth factor antisense (EGFRAS) gene therapy compared to non-responding tumors or tumors treated with control sense plasmid DNA. These findings indicate that [(18)F]FLT PET imaging may be useful in monitoring SCCHN response to molecular targeted therapies, while [(18)F]FDG uptake in SCCHN xenografts may not be reflective of the level of metabolic activity characteristic of human SCCHN tumors.