Clinical and electrophysiological characteristics of extra-pulmonary vein triggers in patients who underwent catheter ablation for atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Background

Extra-pulmonary vein (PV) triggers play significant roles in atrial fibrillation (AF) recurrence after AF catheter ablation (AFCA).

Purpose

We explore the clinical and electrophysiological characteristics of extra-PV triggers in de novo and repeat-AFCA procedure.

Methods

We included 2,151 patients who had de novo AFCA and 319 repeat AFCA (female 28.0%, 59.1 ± 10.8 years old, paroxysmal AF 65.1%) those underwent post-procedural isoproterenol (ISO) provocation tests. We analysed the clinical, electrophysiological, and procedure-related factors associated with extra-PV triggers.

Results

Extra-PV triggers were documented in 11.9% (1.19 ± 0.42 foci) after de novo-AFCA and 27.0% (1.37 ± 0.65 foci) after repeat-AFCA (p = 0.004). LA volume index (OR 1.02 [1.01-1.03], p = 0.004), history of vascular disease (OR 0.55[0.31-0.91], p = 0.028) and Lead I amplitude of electrocardiogram (OR <0.01 [<0.01-0.62], p = 0.032) were independently associated with the existence of extra-PV triggers in de-novo procedure. Women (OR 1.84 [1.03-3.25], p = 0.037) and LA appendage volume (OR 1.04 [1.01-1.07] p = 0.027) were independently associated with extra-PV triggers during the redo-mapping procedure. Septum (28.4%), coronary sinus (24.0%), and superior vena cava (19.6%) were common extra-PV foci, and septal foci were more commonly found in repeat mapping (38.4% vs. 25.0%, p = 0.025). Among 65 patients who showed extra-PV at the repeat procedures, 19 (29.2%) matched with previous focal or empirical extra-PV ablation sites and 9 (13.8%) were multiple or unmappable sites. AF recurrence rates were significantly higher in both patients with extra-PV triggers after de novo procedures (Log-rank P <0.001; HR 1.93 [1.58-2.36], p= <0.001) and repeat procedures (Log-rank P <0.001, HR 1.87 [1.29-2.70], p= <0.001).

Conclusion

ISO provoked extra-PV triggers commonly found in AF patients with significant remodelling and previous empirical or focal extra-PV ablations. Existence of extra-PV triggers were independently associated with poorer rhythm outcome after both de novo and repeat AFCA. Denovo AF ablation outcome OverallExtra-PV triggers (-)Extra-PV triggers (+)p-value(n = 2151)(n = 1895)(n = 256)Age, yrs58.98 ± 10.9558.73 ± 11.0360.76 ± 10.200.006Male, (%)1550 ( 72.1)1389 ( 73.3)161 ( 62.9)0.001Follow up duration, month50.30 (37.71)51.65 (37.95)40.71 (34.58)<0.001Early recurrence (%)579 ( 27.8)455 ( 24.9)124 ( 48.4)<0.001Clinical recurrence (%)699 ( 33.6)584 ( 32.0)115 ( 44.9)<0.001Abstract Figure. AF free survival according to Extra PVT

Long-term outcomes of empirical extra-pulmonary vein linear ablation in patients with persistent atrial fibrillation

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by grants [HI18C0070] and [HI19C0114] from the Korea Health 21 R&D Project, Ministry of Health and Welfare, and a grant [NRF-2020R1A2B01001695] from the Basic Science Research Program run by the National Research Foundation of Korea (NRF).

Background

Although extra-pulmonary vein (PV) left atrial (LA) linear ablation has been performed during catheter ablation (CA) of persistent atrial fibrillation (PeAF), the long-term efficacy and safety of this procedure have not yet been verified.

Purpose

We investigated whether an anterior line (AL) and posterior box ablation (POBA) in addition to circumferential PV isolation (CPVI) improves the rhythm without worsening the LA function in PeAF patients.

Methods

We retrospectively compared the additional AL + POBA and CPVI alone groups in 604 patients with PeAF who underwent regular rhythm follow-ups (16.9%; males 79.3%, 58.5 ± 10.7 years of age) after propensity score matching. The primary endpoint was AF recurrence after single procedures and secondary endpoints were the cardioversion rate, response to anti arrhythmic drugs, LA changes, and re-conduction rates of the de-novo ablation lesion set.

Results

After a mean follow-up of 45.2 ± 33.6 months, the clinical recurrence rate did not significantly differ between the two groups (log-rank p = 0.554) despite longer procedure times in the AL + POBA group (p < 0.001). Atrial tachycardia recurrences (p = 0.001) and the cardioversion rates after ablation (p < 0.001) were higher in the AL + POBA group than CPVI group. AL + POBA was associated with better rhythm outcomes in patients with large anterior LA volume indices (p for interaction 0.037) and low mean LAA(left atrial appendage) voltages (p for interaction 0.019). In repeat procedures, the LA pulse pressure elevation was significant after the AL + POBA.

Conclusion

In patients with PeAF, an AL + POBA in addition to the CPVI did not improve the rhythm outcomes nor influence the long-term safety, and lead to more extended procedures. Procedure outcomes OverallAL + POBACPVIp-value(n = 604)(n = 302)(n = 302)Procedure time, min190.8 ± 62.6226.9 ± 49.4154.6 ± 52.8<0.001Ablation time, sec5079 ± 19566420 ± 13723738± 1475<0.001Overall complications24 (4.0)13 (4.3)11 (3.6)0.835Early recurrence, n (%)277 (45.9)129 (42.7)148 (49.0)0.142Recurrence type AT, n (% in early recur)77 (27.8)51 (39.5)26 (17.6)<0.001Clinical recurrence within 1-year, n(%)116 (19.2)52 (17.2)65 (21.5)0.256Recurrence type AT, n (% in clinical recur)60 (23.1)46 (30.7)14 (12.7)0.001Cardioversion, n (% in total recur/ % overall)105 (40.4/17.4)74 (49.3/24.5)31 (28.1/10.3)<0.001POBA, posterior box ablation; AL, anterior line; CPVI, circumferential pulmonary vein isolation; AT, atrial tachycardia;Abstract Figure. Long term ablation outcome

Downstream changes in river avulsion style are related to channel morphology

One of the most dramatic events in river environments is the natural diversion, or avulsion, of a channel across its floodplain. Though rarely witnessed, avulsions can cause massive floods, and over geologic time they create most of the fluvial stratigraphic record. Avulsions exhibit behavior ranging from reoccupying abandoned channels to constructing new channels and splay complexes. To quantify avulsion behavior, or style, we measure avulsion-related floodplain disturbance in modern environments. We show that for 63 avulsions from Andean, Himalayan, and New Guinean basins, avulsion style correlates with channel morphology and changes systematically downstream. Avulsions in braided rivers reoccupy abandoned channels, whereas avulsions in meandering rivers often produce flooding and sediment deposition during channel construction. These downstream changes in avulsion style can explain the abrupt transition from channel-dominated to floodplain-dominated facies commonly observed in foreland basin stratigraphy. These dynamics also explain why some avulsions are more hazardous than others.

River avulsions are dramatic events that can cause the loss of many human lives. The authors here investigate how river avulsion style changes with river morphology, and how these changes impact flooding and stratigraphy.

Prediction of radiographic abnormalities by the use of bag-of-features and convolutional neural networks

This study evaluated the feasibility of bag-of-features (BOF) and convolutional neural networks (CNN) for computer-aided detection in distinguishing normal from abnormal radiographic findings. Computed thoracic radiographs of dogs were collected. For the purposes of this study, radiographic findings were used to distinguish between normal and abnormal in the following areas: (1) normal cardiac silhouette vs. cardiomegaly, (2) normal lung vs. abnormal lung patterns, (3) normal mediastinal position vs. mediastinal shift, (4) normal pleural space vs. pleural effusion, and (5) normal pleural space vs. pneumothorax. Images for training and testing the models consisted of ventrodorsal and lateral projection images of the same scale. The number of images used for each finding are as follow: 3142 for cardiomegaly (1571 normal and 1571 abnormal from 1143 dogs), 2086 for lung pattern (1043 normal and 1043 abnormal from 1247 dogs), 892 for mediastinal shift (446 normal and 446 abnormal from 387 dogs), 940 for pleural effusion (470 normal and 470 abnormal from 284 dogs), and 78 for pneumothorax (39 normal and 39 abnormal from 61 dogs). All data samples were divided so that 60% would be used for training the algorithms and 40% for testing the two models. The performance of the classifiers was evaluated by calculating the accuracy, sensitivity and specificity. The accuracy of both models ranged from 79.6% to 96.9% in the testing set. CNN showed higher accuracy (CNN; 92.9-96.9% and BOF; 79.6-96.9%) and sensitivity (CNN; 92.1-100% and BOF; 74.1-94.8%) than BOF. In conclusion, both BOF and CNN have potential to be useful for improving work efficiency by double reading.

A phase II study of gemcitabine-based chemoradiotherapy (CCRT) after triplet induction chemotherapy (ICT) for locally advanced pancreatic cancer (LAPC): A Taiwan Cooperative Oncology Group (TCOG) study

e15562

The optimal management of LAPC remains controversial. The efficacy of CCRT is hampered by early systemic dissemination. To treat undetectable metastases and to select patients who are likely to benefit from CCRT, ICT followed by CCRT has recently been extensively evaluated in LAPC. Recently, we showed that triplet chemotherapy consisting of gemcitabine 800 mg/m2 (10 mg/m2/min) followed by oxaliplatin 85 mg/m2 and 48-hour infusion of 5-FU/LV 3,000 and 150 mg/m2 Q 2 weeks, the GOFL regimen, is feasible and active for pts with APC. Chemo-naïve pts with histo- /cytologically proven unresectable LAPC, and bi-dimensionally measurable diseases were eligible. Patients who did not experience disease progression (PD) after 6 cycles of GOFL would had CCRT consisting of weekly gemcitabine 400mg/m2 plus 50.4Gy/28 fractions of radiation 4–6 weeks later. After CCRT, pts were re-evaluated for surgical intervention and those with unresectable disease would continue GOFL until PD, unacceptable toxicity, patient's refusal or death. Among the 50 enrolled pts (24F/26M, median age 58.5 years), 48 had definitively unresectable diseases. After induction GOFL, 16 (32%) pts were off-studied because of PD in 12 (24%) and ICT-related toxicity in 4 (8%, PD/UE group). Among the 34 (68%) with objective response or stable disease after 6 cycles of ICT, 27 (54%) who completed the assigned multimodality treatment are categorized as CCRT group; whiles 7 (14%) who either declined CCRT (in 5) or still on ICT (in 2) are categorized as non-CCRT group. The median PFS and OS for the ITT population were 9.1 and 14.5 months, respectively. The median PFS for PD/UE, non-CCRT and CCRT groups were 2.1, 8.2 and 12.8 months, respectively; whiles the OS were 8.5, 15.0 and 18.3 months, respectively. The most common grade 3–4 toxicities were neutropenia (40%), anemia (14%), infection (16%), nausea (26%), vomiting (20%). Grade 2–3 peripheral neuropathy was observed in 7 of 29 who received post-CCRT GOFL. Conclusion: Three months of triplet ICT followed by gemcitabine-based CCRT is feasible and likely to prolong the survival of selected LAPC pts. Prospective, randomization study is warranted to validate the findings.

No significant financial relationships to disclose.

A phase II study of gefitinib as first line treatment for good performance advanced or metastatic non-small cell lung cancer in East Asian patients

7167

Background: Gefitinib is an effective treatment for chemotherapy-treated nonsmall cell lung cancer (NSCLC) in East Asian patients. There were only limited prospective studies on the use of gefitinib in chemonaive advanced or metastatic NSCLC patients. Methods: Eligibility included histological or cytological proven chemonaive stage IIIB/IV NSCLC, measurable disease, ECOG performance status of 0–2, good organ functions and candidate for platinum-based chemotherapy. Patients were treated with 250mg gefitinib per day. Tumor assessments were performed every two months by RECIST criteria. Responding patients were treated until progression. Patients with stable disease more than 2 months may continue treatment or shift to chemotherapy. The primary objective of this study was overall response rate of patients. Secondary objectives included 1-year progression-free survival, overall survival, and ancillary biomarker studies. Simon’s two-stage design was used to aim at a response rate more than 20%. Forty-four patients were planned in stage one and the study will be terminated if 5 or less patients responded to the treatment. A total of 106 patients are planned. Results: The planned interim analysis on the first 44 patients is reported here. There were 13 male and 31 female, median age was 63 (range 39–86), ECOG performance status of 0/1/2 were 0/40/4. 33 patients were nonsmokers. 39 patients had adenocarcinoma. The side effects of the treatment were mild and well accepted by patients. There were 24/9/10/1 patients with PR/SD/PD/NE. Overall response rate was 54.5% and disease control rate was 75%. The response rates for female / adenocarcinoma / nonsmoker were 58%/59%/61% respectively. The response rates for male / non-adenocarcinoma / smoker patients were 46%/20%/36%. The median time to progression for all patients was 6.3 months. Conclusions: Gefitinib is a very effective treatment for East Asian chemonaive advanced or metastatic NSCLC patients. Although the patients’ number was small, the response rates for patients with one unfavorable predictive factor were comparable to the response rates of patients receiving combination chemotherapy. The response rates and duration for 106 patients will be presented in the meeting.

[Table: see text]

Selective cytotoxicity of azatyrosinamides against ras-transformed NIH 3T3 cells

This study aims to develop novel azatyrosinamide compounds structurally modified from ras-specific antioncogenic azatyrosine. Analogues 4-15 were prepared and their inhibition on the growth of wild-type and ras-transformed NIH 3T3 cell lines was compared. Compound 12 was found to be the most active with IC50 16.5+/-2.2 microM which is 458-fold more potent than that of azatyrosine. The selective toxicity, defined as IC(50 wild-type)/IC(50 ras-transformed) for this compound was 138.5.

Does experience influence judgments of pain behaviour? Evidence from relatives of pain patients and therapists

OBJECTIVE

Judgments about an individual's pain can be profoundly important to sufferers. Relatively few studies have examined variables that may affect observers' judgments of the pain of others. The present article reports two studies investigating the relationship between different kinds of exposure to pain problems and observers' ratings of the pain intensity of patients.

DESIGN

In the first study, 82 observers were classified into groups with positive and negative family histories of chronic pain. They viewed a videotape showing the facial expressions of shoulder pain patients undergoing physiotherapy assessments and rated the pain experienced by the subjects. In the second study, the data from observers having no experience with pain problems were compared with data collected from therapists having considerable experience with pain problems.

RESULTS

Observers with a positive family history of chronic pain attributed greater pain to the patients than those with a negative family history of chronic pain. Professionals' pain judgments were lower than those of control subjects.

CONCLUSIONS

Together, the findings imply that one's experiences with the different problems of pain patients may affect pain judgments. Alternative interpretations of the findings are considered.

Parenteral nutrition support after bone marrow transplantation: comparison of total and partial parenteral nutrition during the early posttransplantation period

OBJECTIVE

Bone marrow transplantation (BMT) usually is indicated if the patient's malignant disease involves the marrow or if hazard to the normal marrow is the limiting factor in the aggressive treatment of disease. The success of BMT depends on a complete team with all the resources needed to ensure optimal results. Aggressive nutrition support after BMT is very important. Adequate parenteral nutrition, total (TPN) or partial, followed by enteral nutrition according to the patient's gastrointestinal function is the important principle.

METHODS

Between 1996 and 2000, 60 patients, 46 male and 14 female, received BMT in Chang Gung Memorial Hospital. Their ages ranged from 6 to 54 y. Standard TPN was used in 40 patients after BMT, and partial parenteral nutrition was used in the remaining 20 patients. TPN was enriched with branched-chain amino acids (BCAA) when the patient's liver functions were impaired, and cyclic TPN was shifted when the patient's liver functions persistently deteriorated.

RESULTS

Most patients improved their nutrition status and increased their body weights, especially those receiving TPN. The patients receiving partial parenteral nutrition decreased their visceral proteins significantly during the course of parenteral nutrition. The BCAA-TPN can maintain a patient's visceral protein better than standard TPN. Only two patients expired because of graft rejection and sepsis; their body weights and nutrition status showed deterioration despite aggressive nutrition support.

CONCLUSIONS

We conclude that the nutrition support for patients with BMT is related to the success of marrow transplantation. Parenteral nutrition support, especially with TPN, is important because of frequent gastrointestinal dysfunction during the posttransplantational period, and it is better at maintaining the nutrition status and body weights of patients after BMT. An oral diet can be resumed after the patient's gastrointestinal function has improved and it can be tolerated.

Inhibition of the expression of inducible nitric oxide synthase and cyclooxygenase-2 in macrophages by 7HQ derivatives: involvement of IkappaB-alpha stabilization

Nitric oxide is an important biological mediator associated with multiple pathophysiological phenomena, such as platelet aggregation, vasodilation, septic shock, and autoimmune diseases. Prostaglandins, derived from cyclooxygenases, play prominent roles in homeostasis and inflammation. In this study, we characterized the effects of 7HQ derivatives (7-[(4-methylene-5-oxo-2-R-2-tetrahydrofuranyl) methoxy]-3,4-dihydrocarbostyril, where R is methyl, phenyl, p-fluorophenyl and p-phenylphenyl; 7HQ-1,-2,-3 and-4, respectively) in murine RAW 264.7 cells, a macrophage-like cell line. Lipopolysaccharide, the active component of endotoxin, significantly induced the expression of inducible nitric oxide synthase and cyclooxygenase-2, leading to the accumulation of nitrite and prostaglandin E(2), respectively. These actions of lipopolysaccharide were inhibited by 7HQ derivatives; additionally, the inhibition of the expression, rather than the activity, of inducible nitric oxide synthase correlated well with that of nitric oxide formation. Western blotting and electrophoretic mobility shift assay results demonstrated that the 7HQ derivatives could effectively inhibit IkappaB-alpha degradation and nuclear factor kappaB (NF-kappaB) translocation. At higher concentrations, 7HQ derivatives also inhibited cyclooxygenase-2 enzyme activity. These results suggest that 7HQ derivatives exhibit inhibitory effects on lipopolysaccharide-induced nitric oxide production and expression of inducible nitric oxide synthase and cyclooxygenase-2 through inhibition of IkappaB-alpha degradation and NF-kappaB activation.