A novel ablation strategy for recurrent atrial fibrillation: Fractionated signal area in the atrial muscle ablation 1-year follow-up.

INTRODUCTION: Treatment of recurrent atrial fibrillation (AF) is sometimes challenging due to non-pulmonary vein (PV) foci. Fractionated signal area in the atrial muscle (FAAM) is a valid predictor of the location of non-PV foci. FAAM ablation has the potential to decrease the recurrence rate of atrial tachyarrhythmia in patients with recurrent AF. We compared the clinical impact of FAAM ablation for recurrent AF, using 1 year follow up date. METHODS: A total of 230 consecutive patients with symptomatic recurrent AF who underwent catheter ablation specifically targeting non-PV foci as FAAM-guided ablation (n = 113) and non-FAAM-guided ablation (n = 117) were retrospectively analyzed. FAAM was assigned a parameter (peaks slider, which indicates the number of components of fractionated signals), ranging from 1 to 15, indicating the location of the FAAM (1: largest, 15: smallest). FAAM-guided ablation was performed by ablating FAAM until none inducibility of non-PV foci. On the other hand, non-FAAM-guided ablation was performed via linear ablation, complex fractionated atrial electrogram ablation, superior vena cava isolation, and focal ablation according to the location of the non-PV foci. The RHYTHMIA system was used to perform all the procedures. The primary endpoints were AF recurrence, atrial flutter, and/or atrial tachycardia. RESULTS: After a 1-year follow up, freedom from atrial tachyarrhythmia was achieved in 90.3% and 75.2% of patients in the FAAM and non-FAAM groups, respectively (hazard ratio = 0.438 [95% confidence interval: 0.243-0.788], p = .005). CONCLUSIONS: FAAM ablation showed a promising decrease in the recurrence rate of atrial tachyarrhythmia in patients with recurrent AF during a 1-year follow-up.

Clinical impact of eliminating nonpulmonary vein triggers of atrial fibrillation and nonpulmonary vein premature atrial contractions at initial ablation for persistent atrial fibrillation.

BACKGROUND: The role of nonpulmonary vein (PV) triggers ablation in persistent atrial fibrillation (PEAF) was suggested but it is still under debate. OBJECTIVES: We aimed to assess the effectiveness of non-PV trigger-targeted ablation for patients with PEAF. METHODS: Consecutive patients with PEAF undergoing catheter ablation (CA) between January 2015 and April 2017 were enrolled. Isoproterenol plus adenosine challenge was performed to provoke non-PV triggers. Non-PV triggers were defined as the trigger beats inducing AF (non-PV AF triggers) and/or frequent premature contractions (non-PV PACs) from other than PVs. Three groups were defined: Group 1 (n = 186) without non-PV triggers; Group 2 (n = 65) with non-PV triggers that could be completely eliminated with CA; Group 3 (n = 49) with non-PV triggers still inducible after CA. The primary endpoint was freedom from any atrial tachyarrhythmia (ATa) recurrence. RESULTS: A total of 300 patients (230 males, age 64 ± 10) were enrolled. The mean follow-up period was 27 ± 10 months. Freedom from ATa recurrence at 1 and 2 years were significantly lower in Group 3 compared to the other two groups (Group 1; 74.7%, 67.2% vs. Group 2; 75.8%, 68.3% vs. Group 3: 52.1%, 38.6%, p = .0005), irrespective of the type of non-PV triggers (non-PV AF triggers vs. non-PV PACs). On multivariate analysis, unsuccessful elimination of non-PV triggers was an independent predictor for ATa recurrence (hazard ratio = 1.80, 95% confidence interval = 1.07-2.95, p = .026). CONCLUSION: Successful non-PV triggers elimination can improve the ATa recurrence rate in PEAF ablation. ATa recurrence rate is higher, if non-PV AF triggers or even non-PV PACs remain in patients with PEAF.

Evaluation of Proteins and Cells that Adsorb to Dialysis Membranes Used in Continuous Hemodiafiltration: Comparison of AN69ST, Polymethylmethacrylate, and Polysulfone Membranes.

OBJECTIVE: In intensive care medicine, continuous renal replacement therapy (CRRT) is important for critically ill patients. Various types of dialysis membranes are currently used in clinical settings, each having unique structures and characteristics. This study aimed to perform a detailed analysis of the characteristics of polysulfone (PS), polymethylmethacrylate (PMMA), and polyacrylonitrile (AN69ST) membranes, and to determine differences in the adsorption of proteins and blood cells by membrane material. METHODS: Subjects were patients undergoing CRRT in the ICU of the Kokura Memorial Hospital. After use, membranes were collected and analyzed. Semi-quantitative analysis of the membrane surface was performed by scanning electron microscopy. We determined the identity of proteins adsorbed to the surface of membranes by TOF/MS analysis, and measured the amount of adsorbed chemical mediators. RESULTS: Electron microscopy revealed that, compared to PS and PMMA membranes, AN69ST membranes had a greater amount of adsorbed activated white blood cells (WBCs). A large amount of platelets was adsorbed to PMMA membranes. In terms of the amount of adsorbed protein, significantly more proteins adsorbed to AN69ST membranes compared to PS and PMMA membranes. Moreover, TOF/MS analysis revealed a difference in the types of adsorbed proteins by membrane. Chemokines were particularly prevalent among adsorbed proteins for all 3 membranes. CONCLUSION: Compared to PS and PMMA membranes, AN69ST membranes had a higher capacity to remove activated WBCs. Moreover, apparent differences were noted in the types of proteins that adsorbed to each type of membrane. These differences in membrane properties may impact clinical outcomes.

Performance comparison of a new automated cuff pressure controller with currently available devices in both basic research and clinical settings.

BACKGROUND: The management of tracheal tube cuff pressure in patients receiving mechanical ventilation is important for the prevention of ventilator-associated pneumonia. Currently, cuff pressure is intermittently monitored with a pressure gauge and adjusted when necessary in a routine practice. However, this method results in wide variations in pressure, and adequate management is difficult due to the spontaneous release of air from the cuff, which reduces cuff pressure. In order to continuously maintain a uniform cuff pressure, we developed a new automated cuff pressure controller and compared its properties with existing devices. METHODS: The effectiveness of the new device was assessed with a model trachea/lung and tracheal tube by measuring cuff pressure while on mechanical ventilation. An electrically powered automatic cuff controller or manual cuff pressure control was used for comparison purposes. The effectiveness of the new device was also examined in patients receiving mechanical ventilation by continuously measuring cuff pressure for a 24-h period. RESULTS: Cuff pressure was uniformly maintained with the new device. Moreover, in the clinical setting, variation in pressure from the set pressure was minimal with both the new device and existing device, relative to the intermittent monitoring method. This suggests that, as with the existing device, uniform cuff pressure management is possible with the new device. CONCLUSIONS: Our results demonstrate the ability of the new cuff pressure controller to manage cuff pressure without the need of a power source, highlighting its potential utility in clinical settings.

Lead extractions in patients with cardiac implantable electronic device infections: Single center experience.

BACKGROUND: Lead extraction using laser sheaths is performed mainly for cardiac implantable electronic device (CIED) infections. However, there are few reports concerning the management of CIED infections in Japan. METHODS AND RESULTS: Lead extraction procedures were performed in 183 patients targeting 450 leads (atrial leads: 170, ventricular: 181, implantable cardioverter-defibrillators (ICDs): 79, and coronary sinus: 20). One hundred twenty patients (65.6%) presented with pocket infections without the presentation of an endovascular infection. Blood cultures were positive at least once in 63 patients (34.4%). Complete procedure success was achieved for 437 leads (97.1%) while partial removal occurred in nine, and failure in four leads. Major complications directly related to the procedure occurred in five patients (2.7%). Two of the four patients with a cardiac tamponade required a surgical repair. All patients received intravenous antibiotics, at least, one week after the procedure. Pocket or systemic infections were successfully controlled in 181 patients (98.9%). Coagulase-negative staphylococci (30.1%) and Staphylococcus aureus (37.1%) were the most common causes of CIED infections. CONCLUSION: The current status of CIED infections in Japan seems to be similar to that previously reported from foreign countries. The optimal treatment of CIED infections involves the complete explantation of all hardware, followed by antibiotic therapy.

Long-term outcomes of catheter ablation of ventricular tachycardia in patients with structural heart disease.

BACKGROUND: Catheter ablation of ventricular tachycardia (VT) is feasible. However, the long-term outcomes for different underlying diseases have not been well defined. METHODS: Eighty-eight consecutive patients who underwent catheter ablation of VT using a three-dimensional mapping system were analyzed. The primary endpoint was any VT or ventricular fibrillation (VF) recurrence. Secondary endpoints were a composite of death or any VT/VF recurrence. Underlying heart diseases were remote myocardial infarction (remote MI) in 51 patients and non-ischemic cardiomyopathy in 37 (arrhythmogenic right ventricular cardiomyopathy [ARVC] in 18 patients, and dilated cardiomyopathy [NIDCM] in 19). RESULTS: Acute success was achieved in 82 of 88 (93%) patients. During a follow-up period of 39.2±4.6 months, VT recurred in 26 of 87 (30%), and VT/VF recurrence or death occurred in 39 of 87 (45%) patients. ARVC had better outcomes than NIDCM for the primary (p<0.05) and secondary endpoints (p<0.05). Remote MI-VT revealed a midrange outcome. CONCLUSIONS: The long-term outcomes after catheter ablation of VT varied according to the underlying heart disease. ARVC-VT ablation was associated with better long-term prognosis than NIDCM. Remote MI-VT demonstrated a midrange outcome.