Impact of contact force on the lesion characteristics of very high-power short-duration ablation using a QDOT-MICRO catheter

Background

Lesion size is reported to become larger as contact force (CF) increases. However, this has not been systematically evaluated in temperature-guided very high-power short-duration (vHPSD) ablation, which was therefore the purpose of this study.

Methods

Radiofrequency applications (90 W/4 s, temperature-control mode) were performed in excised porcine myocardium with four different CFs of 5, 15, 25, and 35 g using QDOT-MICRO™ catheter. Ten lesions for each combination of settings were created, and lesion metrics and steam-pops were compared.

Results

A total of 320 lesions were analyzed. Lesion depth, surface area, and volume were smallest for CF of 5 g than for 15, 25, and 35 g (depth: 2.7 mm vs. 2.9 mm, 3.0 mm, 3.15 mm, p < .01; surface area: 38.4 mm2 vs. 41.8 mm2, 43.3 mm2, 41.5 mm2, p < .05; volume: 98.2 mm3 vs. 133.3 mm3, 129.4 mm3, 126.8 mm3, p < .01 for all pairs of groups compared to CF = 5 g). However, no significant differences were observed between CFs of 15-35 g. Average power was highest for CF of 5 g, followed by 15, 25, and 35 g (83.2 W vs. 82.1 W vs. 77.1 W vs. 66.1 W, p < .01 for all pairs), reflecting the higher incidence of temperature-guided power titration with greater CFs (5 g:8.8% vs. 15 g:52.5% vs. 25 g:77.5% vs. 35 g:91.2%, p < .01 for all pairs except for 25 g vs. 35 g). The incidence of steam-pops did not significantly differ between four groups (5 g:3.8% vs. 15 g:10% vs. 25 g:6.2% vs. 35 g:2.5%, not significant for all pairs).

Conclusions

For vHPSD ablation, lesion size does not become large once the CF reaches 15 g, and the risk of steam-pops may be mitigated through power titration even in high CFs.

Effect of reference electrode on intracardiac electrograms: Close indifferent electrode vs Wilson central terminal

BACKGROUND

Unipolar electrograms (uni-EGMs) are an essential part of intracardiac mapping. Although Wilson central terminal (WCT) is conventionally used as a reference for signals, avoidance of contamination by far-field and nonphysiologic signals is challenging.

OBJECTIVE

The aim of the study was to explore the impact of an intracardiac indifferent reference electrode close to the recording electrodes, in lieu of WCT, on electrograms.

METHODS

Sinus node activation was mapped in patients undergoing catheter ablation by a multielectrode array with a close indifferent electrode (CIE) embedded in the distal end of the catheter shaft. An equal number of points was sequentially acquired at each site with use of CIE as a reference first and subsequently with WCT. Uni-EGMs, bipolar EGMs, and the earliest activation area (defined as the area activated in the first 10 ms of the beat) were compared between CIE- and WCT-based activation maps.

RESULTS

Seventeen patients (61 ± 18 years; 76% male) were studied. Uni-EGM voltages acquired with CIE were significantly larger than (n = 11) or comparable to (n = 4) those acquired with WCT. When points from the entire cohort were analyzed altogether, unipolar voltages and their maximum negative dV/dT and bipolar voltages recorded with CIE were significantly larger than those recorded with WCT (2.36 [1.42-3.79] mV vs 1.96 [1.25-3.03] mV, P < .0001; 0.40 [0.18-0.77] mV/s vs 0.35 [0.15-0.71] mV/s, P < .0001; and 1.46 [0.66-2.81] mV vs 1.33 [0.54-2.64] mV, P < .0001, respectively). The earliest activation area was significantly smaller in CIE-based activation maps than in WCT-based ones (0.3 [0.7-1.4] cm2 vs 0.6 [1.0-1.8] cm2, P = .01).

CONCLUSION

CIE-based maps were associated with an approximately 20% increase in unipolar voltage and may highlight the origin of a focal activation more clearly than WCT-based ones.

Can phrenic nerve injury be anticipated by larger cryoballoons?

Recently, a novel size-adjustable cryoballoon has been introduced in clinical practice, which can be inflated to two different diameters (28 and 31 mm). The 31 mm cryoballoon is specifically designed to achieve better contact with remodeled pulmonary veins (PVs) that have wider ostia while avoiding deep cannulation, thereby potentially reducing the risk of phrenic nerve injury (PNI) associated with deep balloon cannulation. However, we encountered two cases of PNI during cryoballoon ablation using the novel system among our initial 25 consecutive case series. Herein, we present two cases that exhibited PNI during freezing of the right superior PV with a size-adjustable balloon. While larger balloons are expected to create a larger area of isolation, the safety of this novel balloon system needs to be evaluated in a large-scale clinical study.

Transcoronary mapping with an over-the-wire multielectrode catheter in scar-related ventricular tachycardia patients

AIMS

The usefulness of coronary venous system mapping has been reported for assessing intramural and epicardial substrates in patients with scar-related ventricular tachycardia (VT). However, there has been little data on mapping from coronary arteries. We investigated the safety and utility of mapping from coronary arteries with a novel over-the-wire multielectrode catheter in scar-related VT patients.

METHODS AND RESULTS

Ten consecutive scar-related VT patients with non-ischaemic cardiomyopathy who underwent mapping from a coronary artery were analysed. Six patients underwent simultaneous coronary venous mapping. High-density maps were created by combining the left ventricular endocardium and coronary vessels. Substrate maps were created during the baseline rhythm with 2438 points (IQR 2136-3490 points), including 329 (IQR 59-508 points) in coronary arteries. Abnormal bipolar electrograms were successfully recorded within coronary arteries close to the endocardial substrate in seven patients. During VT, isthmus components were recorded within the coronary vessels in three patients with no discernible isthmus components on endocardial mapping. The ablation terminated the VT from an endocardial site opposite the earliest site in the coronary arteries in five patients.

CONCLUSION

The transcoronary mapping with an over-the-wire multielectrode catheter can safely record abnormal bipolar electrograms within coronary arteries. Additional mapping data from the coronary vessels have the potential to assess three-dimensional ventricular substrates and circuit structures in scar-related VT patients.

Safety verification of a novel irrigation catheter with flexible tip of laser-cut kerfs and contact force sensor

BACKGROUND AND AIMS

The safety evaluation of TactiFlex, a novel contact-force sensing catheter with a flexible 4-mm tip irrigated through laser-cut kerfs, has been ongoing. This study aimed to verify the safety of this type of catheter.

METHODS

Study 1: Radiofrequency (RF) applications at a range of powers (30-50 W), contact forces (10-20 g), and durations (10-60 s) using perpendicular/parallel catheter orientation with half-normal (HNS) or normal saline irrigation were compared between TactiFlex (4-mm tip) and TactiCath (3.5-mm tip) with temperature-controlled mode in excised porcine hearts. Study 2: The relation between RF applications using TactiFlex and the incidence of steam-pops in the real clinical cases were examined.

RESULTS

Study-1: 576 RF lesions were examined. TactiFlex demonstrated a significantly lower risk of steam-pops (5[1.7%] vs. 59[20.5%], p < .0001). Compared to 3.5-mm-tip catheter (TactiCath), 4-mm-tip catheter (TactiFlex) produced smaller lesion volume at perpendicular (193[98-554]mm3 vs. 263[139-436]mm3 , p < .0001), but relatively similar lesion volume at parallel contact (243[105-443]mm3 vs. 278[180-440]mm3 , p = .06). HNS-irrigation tended to increase the lesion volume in both catheters and to increase the incidence of steam-pops with TactiCath, but not with TactiFlex. The cut-off value of %impedance-drop ( = absolute impedance-drop/initial impedance) of 20% predicted steam-pops with a sensitivity = 100% and specificity = 89.6% in TactiFlex. Study-2: 5496 RF applications in 84 patients (51AFs/8ATs/3AVNRTs/4AVRTs/17PVCs/4VTs) using TactiFlex were analyzed. Four steam-pops (0.07%) in three patients with pericardial effusion were observed (%impedance-drop = 24%/26%/29%/35%, respectively). The cut-off value of %impedance-drop = 20%, derived from ex-vivo study, showed sensitivity = 100% and specificity = 90.1% in detecting steam-pops.

CONCLUSION

TactiFlex reduced the risk of steam-pops than TactiCath. %impedance-drop ≤ 20% may be reasonable for safely use with a sufficient safety margin. For 4-mm-tip catheter, parallel-contact may be recommended for larger lesion creation.

Superiority of the Combination of Input and Output Parameters to the Single Parameter for Lesion Size Estimation

BACKGROUND

For lesion size prediction, each input parameter, including ablation energy (AE), and output parameter, such as impedance, is individually used. We hypothesize that using both parameters simultaneously may be more optimal.Methods and Results: Radiofrequency applications at a range of power (30-50 W), contact force (10 g and 20 g), duration (10-60 s), and catheter orientation with normal saline (NS)- or half-normal saline (HNS)-irrigation were performed in excised porcine hearts. The correlations, with lesion size of AE, absolute impedance drop (∆Imp-drop), relative impedance drop (%Imp-drop), and AE*%Imp-drop were examined. Lesion size was analyzed in 283 of 288 lesions (NS-irrigation, n=142; HNS-irrigation, n=141) without steam pops. AE*%Imp-drop consistently showed the strongest correlations with lesion maximum depth (NS-irrigation, ρ=0.91; HNS-irrigation, ρ=0.94), surface area (NS-irrigation, ρ=0.87; HNS-irrigation, ρ=0.86), and volume (NS-irrigation, ρ=0.94; HNS-irrigation, ρ=0.94) compared with the other parameters. Moreover, compared with AE alone, AE*%Imp-drop significantly improved the strength of correlation with lesion maximum depth (AE vs. AE*%Imp-drop, ρ=0.83 vs. 0.91, P<0.01), surface area (ρ=0.73 vs. 0.87, P<0.01), and volume (ρ=0.84 vs. 0.94, P<0.01) with NS-irrigation. This tendency was also observed with HNS-irrigation. Parallel catheter orientation showed a better correlation with lesion depth and volume using ∆Imp-drop, %Imp-drop, and AE*%Imp-drop than perpendicular orientation.

CONCLUSIONS

The combination of input and output parameters is more optimal than each single parameter for lesion prediction.

The effect of half-normal saline irrigation on lesion characteristics in temperature-flow-controlled ablation

PURPOSE

Radiofrequency (RF) ablation with half-normal saline (HNS) irrigation is reported to potentially enlarge local lesion compared to normal saline (NS) in power-controlled ablation (PC-Abl). However, the effect of HNS-irrigation in temperature-flow-controlled ablation (TFC-Abl) on lesion characteristics is unknown. We compared this between TFC-Abl with QDOT-Micro™ catheter and PC-Abl with Thermocool SmartTouch SF™ catheter (STSF).

METHODS

RF-application with NS (n = 480) and HNS (n = 480) irrigation were performed on swine myocardium placed in a circulating saline bath. Lesion characteristics without steam-pops under various conditions (target AI, 400/550; ablation power, 30/50 W; contact force, 10/20/30 g; catheter orientation, perpendicular/parallel) were assessed and compared between two irrigants.

RESULTS

After matching, 343 lesions without steam-pops in each group were evaluated. In PC-Abl, lesion size did not differ between two groups (NS, 188 ± 97 vs. HNS, 200 ± 95 mm3, p = 0.28 in volume; 33.9 ± 7.3 vs. 34.8 ± 9.5 mm2, p = 0.34 in surface area; and 4.0 ± 1.0 vs. 4.0 ± 1.0 mm, p = 0.81 in depth), but steam-pops were more frequently observed with HNS-irrigation (23.8% vs. 37.9%, p = 0.001). Contrary, in TFC-Abl, HNS-irrigation produced significantly larger (214 ± 106 vs. 243 ± 128 mm3, p = 0.017) and deeper (4.0 ± 1.0 vs. 4.3 ± 1.1 mm, p = 0.002) lesions without increasing the risk of steam-pops (15.0% vs 15.0%, p = 0.99). Automatic temperature-guided titration was more frequently observed in HNS-irrigation (54.8% vs. 78.5%, p < 0.001).

CONCLUSIONS

TFC-Abl with QDOT-Micro™ catheter utilizing HNS-irrigation might increase volume and depth of local lesion without increasing the risk of stem-pops compared to NS-irrigation. Power-controlled ablation with HNS-irrigation showed similar focal lesion with higher incidence of steam-pops (SPs) compared to normal saline (NS) irrigation. Contrary, temperature-flow-controlled ablation with HNS-irrigation provided larger and deeper lesion than NS-irrigation with similar incidence of SPs. ns, p > 0.05; *, 0.01 < p ≤ 0.05; **, 0.005 < p ≤ 0.01. HNS, half-normal saline; NS, normal saline.

Effect of isolation feasibility of non-pulmonary vein foci on efficacy of ablation for atrial fibrillation: comparison of the isolation and focal ablation methods

PURPOSE

Atrial fibrillation (AF) mainly originates from the pulmonary vein (PV). However, some AF triggers originate from other sites, namely non-PV foci, which are related to recurrence after AF ablation. This study aimed to evaluate the effects of isolation feasibility (isolability) of non-PV foci on the efficacy of AF ablation.

METHODS

Overall, 1855 patients with AF (age, 64.6 ± 10.9 years; 82% paroxysmal) underwent PV isolation, followed by induction and ablation of non-PV foci. Among them, 545 (29%) patients had non-PV foci; these patients were categorized into those with isolable non-PV foci (n = 196, 36%) and those with non-isolable non-PV foci (n = 349, 64%).

RESULTS

During a mean follow-up of 31.2 ± 15.6 months, recurrence was higher in the non-isolable group than in the isolable group (34% vs. 19%, P < 0.01). Kaplan-Meier analyses revealed a significantly better 1-year clinical outcome in the isolable group than in the non-isolable group (88.0% vs. 78.4%, P < 0.001; hazard ratio (HR), 0.56; 95% confidence interval (CI), 0.39-0.81). This outcome was not inferior to that of patients without non-PV foci (88.3% vs. 90.8%, P = 0.81). The non-isolable group showed poorer clinical outcomes than patients without non-PV foci (78.4% vs. 90.8%, P < 0.001; HR, 1.37; 95% CI, 1.22-1.53). Cox regression analysis revealed that isolability (HR, 0.56; 95% CI, 0.36-0.89) and unmappability (HR, 2.89; 95% CI, 1.55-5.37) of non-PV foci were significant predictors of arrhythmia recurrence.

CONCLUSION

The isolability of non-PV foci was a significant factor affecting the achievement of better clinical outcomes following AF ablation in patients with non-PV foci.

Impact of diagnosis-to-ablation time on non-pulmonary vein triggers and ablation outcomes in persistent atrial fibrillation

INTRODUCTION

Non-pulmonary vein (PV) triggers are a major cause of atrial tachyarrhythmia (ATA) recurrence after catheter ablation. However, the effect of the diagnosis-to-ablation time (DAT) on non-PV triggers in persistent atrial fibrillation is unknown.

METHODS AND RESULTS

This observational study evaluated 502 consecutive persistent AF patients who underwent initial ablation. We compared 408 patients whose DAT was <3 years with 94 patients whose DAT was ≥3 years. Following PV and posterior wall isolation, 193 non-PV triggers, including 50 AFs, 30 atrial tachycardias (ATs), and 113 repetitive atrial premature beats, were elicited and ablated in 137 (27%) patients. Specifically, 80 non-PV AF/AT triggers were provoked in 64 (13%) patients, being identified more frequently in the DAT ≥ 3 years group than in the DAT < 3 years group (20% vs. 11%, p = .025) especially with a higher prevalence of coronary sinus/inferior left atrial triggers. During a median follow-up of 770 days, the ATA recurrence-free rate was higher in the DAT < 3 years group than the DAT ≥ 3 years group (79% vs. 53% at 2 years, p < .001). In a multivariate analysis, female sex (odds ratio: 2.70, p = .002) and a longer DAT (odds ratio: 1.13/year, p = .008) were predictors of non-PV AF/AT triggers, and a longer DAT (hazard ratio: 1.12/year, p < .001) and non-PV AT/AF triggers (hazard ratio: 1.79, p = .009) were associated with ATA recurrence.

CONCLUSION

Early ablation after the first diagnosis of persistent AF may reduce emerging non-PV AF/AT triggers and ATA recurrence.

The impact of left atrium size on selection of the pulmonary vein isolation method for atrial fibrillation: Cryoballoon or radiofrequency catheter ablation

BACKGROUND

Pulmonary vein isolation (PVI) is the cornerstone of ablation strategies for atrial fibrillation (AF), and noninferiority of cryoballoon (CB) over radiofrequency (RF) ablation has been previously reported. One of the risk factors of recurrence is left atrium (LA) enlargement. This study aimed to analyze the impact of LA enlargement on the selection of CB or RF ablation for AF patients.

METHODS

A total of 2,224 AF patients (64.4 ± 10.7 years, 65.5% male) who underwent PVI were analyzed retrospectively. Left atrial diameter (LAD) and volume (LAV) were measured using echocardiography before the procedures. LA enlargement was defined as LAD ≥40 mm and LAV index (LAVI) ≥35 mL/m². Patients undergoing CB and RF ablation were propensity score matched, and 376 matched pairs were evaluated.

RESULTS

Cox proportional hazard analysis revealed that LAD (95% CI, 1.01-1.05), LAV (95% CI, 1.01-1.02), and LAVI (95% CI, 1.01-1.03) were independent predictors of recurrence. CB showed equivalent clinical outcomes to those of RF with shorter procedure time required for patients without LA enlargement. CB was inferior to RF in patients with LA enlargement (LAD, 74.5% vs 84.6%, P = .028; LAVI, 74.7% vs 83.4%, P = .015), and large LAVI was associated with a higher prevalence of non-PV foci (35% vs 29%, P = .008).

CONCLUSIONS

CB ablation may be recommended for patients without enlarged LA based on the short procedure time and efficacy, whereas RF would be more appropriate in large LAs. LAVI may be a valuable reference to predict PVI outcomes and in selecting the ablation method.

Pulmonary vein isolation for atrial fibrillation patients with reduced left ventricular ejection fraction

 

Background/Introduction Pulmonary vein isolation (PVI) is a cornerstone of curable treatment for atrial fibrillation (AF). Left ventricular (LV) ejection fraction (EF) occasionally improves after PVI in AF patients with reduced LVEF (rEF), the mechanism of which is not fully understood. CASTLE-AF trial have demonstrated that PVI with radiofrequency (RF) catheter for AF patients with rEF can reduce their mortality and heart failure. Nevertheless there are limited data about the clinical outcome of the PVI for patients with impaired LV function.

Purpose

This study was to evaluate the efficacy of PVI and improvement of LVEF after the procedure in AF patients with rEF.

Methods

A total of 2709 consecutive AF patients (age 65±39 y/o, male 67%) underwent their first PVI with cryoballoon or RF catheter in our facility from April 2014 to March 2019, and retrospectively analyzed. All the patients underwent echocardiogram before and half to one year after the procedure. Patients with LVEF under 40% before the PVI were selected (n=111) and divided into two groups based on whether there were specific etiologies of LV function impairment (group A) or not (group B).

Results

There were no significant difference in mean LVEF between group A (n=40) and group B (n=71) (32±6% vs 33±6%, p=0.12). The major etiology of rEF in group A were old myocardial infarction (n=20, 18%), hypertensive heart disease (n=6, 5.4%), and dilated cardiomyopathy (n=5, 4.5%). After mean follow-up of 2.7 years, there were no significant difference in clinical outcome after the procedure between two groups (1-year Kaplan–Meier event rate estimates; 72.2% vs 72.9%; p=0.85). The change amounts of LVEF after the PVI were significantly higher in group B (20±14%) compared to group A (2±10%) (p&lt;0.001). Multivariable Cox regression analysis revealed that age was the independent significant predictors of EF improvement over 10% in group B (p=0.048).

Conclusions

In AF patients with reduced LVEF, there were no significant difference in efficacy of PVI between those who have specific etiologies of LV function impairment other than AF and who have not. The improvement of LVEF after PVI was significantly larger in patients without specific etiologies compared to those with.

Funding Acknowledgement

Type of funding source: None

The Sequential Organ Failure Assessment (SOFA) score predicts mortality and neurological outcome in patients with post-cardiac arrest syndrome

BACKGROUND

Patients experiencing out-of-hospital cardiac arrest (OHCA) and subsequent post-cardiac arrest syndrome are often compromised by multi-organ failure. The Sequential Organ Failure Assessment (SOFA) score has been used to predict clinical outcome of patients requiring intensive care for multi-organ failure. Thus, the assessment of SOFA score is recommended as a criterion for sepsis. Although post-cardiac arrest patients frequently develop sepsis-like status in ICU, there are limited reports evaluating the SOFA score in post-cardiac arrest patients. We investigated the predictive value of the SOFA score in survival and neurological outcomes in patients with post-cardiac arrest syndrome.

METHODS

A total of 231 cardiovascular arrest patients achieving return of spontaneous circulation (ROSC) were finally extracted from the institutional consecutive database comprised of 1218 OHCA patients transferred to the institution between January 2015 and July 2018. The SOFA score was calculated on admission and after 48h. Predictors of survival and neurological outcome defined as having cerebral-performance-category (CPC) 1 or 2 at 30 days were determined.

RESULTS

SOFA score was lower in survived patients (5.0 vs 10.0, p<0.001) and those with favorable neurological outcome (5.0 vs 8.0, p<0.001) as compared with the counterparts. The SOFA score on admission was an independent predictor of survival (OR 0.68, 95% confidence interval [CI] 0.59-0.78; p<0.001) and favorable neurological performance (OR 0.79; 95% CI 0.69-0.90; p<0.001) at 30 days. Furthermore, a change in SOFA score (48-0h) was predictive of favorable 30-day neurological outcome (OR 0.71, 95% CI 0.60-0.85; p<0.001).

CONCLUSIONS

Evaluation of the SOFA score in the ICU is useful to predict survival and neurological outcome in post-cardiac arrest patients.

P1918Comparison of the clinical outcome of pulmonary vein isolation with cryoballoon and radiofrequency ablation for atrial fibrillation with pulmonary vein triggers

Background

Pulmonary vein isolation (PVI) using radiofrequency (RF) or cryoballoon (CB) has been an established treatment for atrial fibrillation. PVI using RF is the most common method with a rather complex technique of a point-by-point tissue heating and navigation of electro-anatomical-guided mapping system, and PVI with CB is also the common method with a relatively simple technique of freezing balloon occlusion. These 2 types of ablation are comparable in terms of the efficacy of the PVI procedure.

Purpose

The data on the clinical outcome of each AF type with PV triggers has been limited. We compared the outcome of success rate between RF and CB group with respect to each AF type, and further assessed the efficacy of pulmonary vein isolation for AF patients with the origin of only PV.

Methods

A total of 3402 AF patients (age 64±11; 2463 males) underwent initial PVI from May 2009 to July 2018 (PAF: 67%, non-PAF: 37%). Radiofrequency using irrigation-tip catheter was employed to 1796 patients since May 2009 (RF-PAF: 55%, RF-non-PAF: 45%). Second-generation cryoballoon was employed to other 1606 patients since September 2014 (CB-PAF: 81%, CB-non-PAF: 19%). In CB group, PV touch-up ablation with RF was needed for 113 patients (7%) (CB-PAF: 6%, CB-non-PAF: 13%; p<0.001). After PVI, additional ablation for non-PV foci was undergone after the induction by using isoproterenol infusion and rapid atrial pacing (RF-AF: 34%, CB-AF: 32%; p=0.107).

Results

In all PAF patients, AF free survival rate was significantly superior in CB group (2-years Kaplan-Meir event rate, CB 83.2%, RF 75.2%; log-rank p<0.001). The percentage of patients with non-PV foci was almost equivalent in both group (CB 30%, RF 31%, p=0.644). And in PAF patients with only PV-foci, AF free survival rate was significantly superior in CB group (2-years Kaplan-Meir event rate, CB 85.0%, RF 78.8%; log-rank p<0.001). On the other hand, in all non-PAF patients, AF free survival rate was almost equivalent in both non-PAF group (2-years Kaplan-Meir event rate, CB 65.5%, RF-non-PAF 70.0%; log-rank p=0.9). The percentage of patients with non-PV foci was almost equivalent in both group (CB 40%, RF 39%, p=0.731), And in non-PAF patients with only PV-foci, AF free survival rate was almost equivalent in both non-PAF group (2-years Kaplan-Meir event rate, CB 69.7%, RF 73.0%; log-rank p=0.376).

Conclusions

Our study showed better outcome of PVI with CB for PAF patients with PV triggers, and indicated the non-inferiority of PVI with CB for non-PAF patients with PV triggers to PVI with RF.

P6380The impact of coronary artery disease to predict mortality and neurological outcome in post-cardiac arrest patients

Background

Some studies reported that performing coronary angiography (CAG) for patients with out-of-hospital cardiac arrest (OHCA) is effective for the prognosis and neurological outcome. However, the impact of complexity of coronary artery disease (CAD) on CAG findings has not been evaluated sufficiently.

Purpose

We sought to investigate the complexity of CAD to predict the prognosis and neurological outcome in patients with OHCA.

Methods

A total of 1382 out-of-hospital cardiac arrest patients were transferred to our critical care center, of which 252 cardiovascular arrest patients achieving the return of spontaneous circulation (ROSC) were extracted from the institutional consecutive database between January 2015 and December 2018. Among those patients, we performed CAG for 160 patients. To predict mortality in hospital and neurological outcome at 30 days, we investigated basic patients' characteristics, pre-hospital information, coronary anatomical angiographical findings.

Results

Ventricular fibrillation (VF) (P=0.001), younger age (P=0.007), pre-hospital ROSC (P<0.001) and normal coronary artery on CAG findings (P=0.014) were associated with low 30-days mortality in hospital. VF (P=0.003), younger age (P=0.004), pre-hospital ROSC (P<0.001), bystander cardiopulmonary resuscitation (CPR) (P=0.043) and normal coronary artery (P=0.001) were associated with good neurological outcome (cerebral-performance-category (CPC) =1 or 2) at 30 days. We further investigated 100 patients who had any coronary artery stenosis on CAG findings. Among these patients, 55 patients (55.0%) had multi-vessel coronary artery disease and 29 patients (29.0%) had at least a chronic total occlusion lesion. VF survivor (P=0.035), without previous history of CAD (P=0.008), pre-hospital ROSC (P=0.013), and Syntax score (P=0.002) were associated with low 30-days mortality. In multivariate analysis, Syntax score (OR 0.94; 95% confidence interval (CI) 0.88–0.99; P=0.042) was independent predictor of mortality. Bystander CPR (P=0.001), pre-hospital ROSC (P<0.001) were associated with good neurological outcome at 30 days. Bystander CPR (OR 5.92; 95% CI 2.01–17.5; P<0.001) and pre-hospital ROSC (OR 9.22; 95% CI 3.34–25.5; P<0.001) were predictive for good neurological outcome.

Conclusions

OHCA patients with any coronary stenosis had high mortality and bad neurological outcome in comparison with those who had normal coronary arteries. OHCA patients with CAD had complex lesions such as multi-vessel disease or chronic total occlusion lesions. The coronary complexity in patients with OHCA was a predictor of in-hospital 30-days mortality. However, pre-hospital care such as bystander CPR and pre-hospital ROSC were the most important to achieve good neurological outcome at 30 days in the present study.

P2266The predictor of mortality and neurological outcome in out-of-hospital cardiac arrest patients with non-ST-segment elevation

Background

The prognosis of patients with out-of-hospital cardiac arrest (OHCA) remains poor. Coronary artery disease (CAD) is the most frequent cause of OHCA. The prompt evaluation and revascularization for coronary artery in OHCA patients with ST-segment elevation are recommended because they often have CAD. However, OHCA patients without ST-segment elevation also have any coronary stenosis in the non-negligible proportion. The predictor of mortality and neurological outcome in OHCA patients with no ST-segment elevation has not been sufficiently elucidated.

Purpose

We sought to investigate the predictor of mortality and neurological outcome at 30 days in OHCA patients without ST-segment elevation.

Methods

A total of 1382 out-of-hospital cardiac arrest patients were transferred to our critical care center, of which 252 cardiovascular arrest patients achieving the return of spontaneous circulation (ROSC) were extracted from the institutional consecutive database between January 2015 and December 2018. Among those patients, 183 patients' electrocardiogram after ROSC were without ST-segment elevation. We performed coronary angiography (CAG) for 103 patients, who were eligible for final analysis. To predict mortality in hospital and neurological outcome at 30 days, we investigated basic patients' characteristics, pre-hospital information, post-hospital care.

Results

Any coronary stenosis was founded in 50 patients (48.5%). Male (P=0.007), older age (P<0.001), past history of coronary artery disease (CAD) (P=0.037) and diabetes mellitus (P=0.087) were associated with coronary artery stenosis on CAG findings. Age (OR 1.05; 95% confidence interval (CI) 1.02–1.08; P<0.001), male (OR 5.33; 95% CI 1.37–20.7; P<0.001) were independent predictors of coronary artery stenosis. Among those who had stenosis, 34 patients (68.0%) survived and 27 patients (54.0%) achieved good neurological outcome (cerebral-performance-category (CPC) =1 or 2) at 30 days. Successful revascularization by percutaneous coronary intervention (PCI) was not associated with low mortality (P=0.77). Past history of CAD (P=0.014) and high Syntax score (P=0.030) were associated with mortality. Bystander cardiopulmonary resuscitation (CPR) (P-0.021), pre-hospital ROSC (P<0.001) was more frequent in patients with good neurological outcome. Pre-hospital ROSC (OR 14.7; 95% CI 3.1–69.3; P<0.001) was independently predictive for good neurological outcome.

Conclusions

Successful PCI for OHCA patients with no ST-segment elevation was not a predictor of mortality. CAD past history and complex CAD was associated with mortality. Pre-hospital information such as pre-hospital ROSC was important to achieve good neurological outcome.

P1919The assessment of the application and the efficacy of pulmonary vein isolation with cryoballoon for non-paroxysmal atrial fibrillation

Background

Pulmonary vein isolation (PVI) using second generation cryoballoon (CB) ablation has become an established treatment for paroxysmal atrial fibrillation (PAF) patients. On the other hand, PVI with radiofrequency (RF) has been an established treatment for non-PAF patients, in addition to PAF patients.

Purpose

The data on second generation CB ablation for non-PAF patients is limited. We assessed the application of PVI with CB for non-PAF patients and compared the outcomes of success rate, radiational time, and procedural time.

Methods

A total of 2632 AF patients (age 64±10; 1873 males) underwent initial PVI from September 2014 to June 2018. Second-generation CB was employed to 1587 patients (CB-PAF: 80%, CB-non-PAF: 20%) and RF using irrigation-tip catheter was employed to other 1045 patients (RF-PAF: 40%, RF-non-PAF: 60%). In CB group, PV touch-up ablation with RF was needed for 113 patients (7%) (CB-PAF: 6%, CB-non-PAF: 13%; p<0.001). After PVI, additional ablation for non-PV foci was undergone after the induction by using ISP infusion and rapid atrial pacing.

Results

AF free survival rate was almost equivalent in both non-PAF group (2-years Kaplan-Meir event rate, CB-non-PAF 66.3%, RF-non-PAF 69.8%; log-rank p=0.297). There was significantly difference in procedural time (CB-non-PAF 132±56min, RF-non-PAF: 189±52min, p<0.001), and radiation time (CB-non-PAF: 47±40min, RF-non-PAF: 75±31min, p<0.001). The percentage of patients with non-PV foci was significantly higher in CB group (CB-non-PAF 41%, RF-non-PAF 54%, p<0.001), and after excluding the patients with non-PV foci, AF free survival rate was almost equivalent in both group (2-years Kaplan-Meier event rate, CB-non-PAF 75.4%, RF-non-PAF 78.8%; log-rank p=0.577). On the other hand, in patients in CB, AF free survival rate was significantly superior in PAF group (2-years Kaplan-Meir event rate, CB-PAF 83.3%, CB-non-PAF 65.2%; log-rank p<0.001). There was significantly difference in procedural time (CB-PAF: 117±47min, CB-non-PAF: 132±56min, p<0.001), and radiation time (CB-PAF: 38±22min, CB-non-PAF: 46±27min, p<0.001). The percentage of patients with non-PV foci was significantly higher in non-PAF group (CB-PAF 30%, CB-non-PAF 41%, p<0.001), and after excluding the patients with non-PV foci, AF free survival rate was also significantly superior in PAF group (2-years Kaplan-Meier event rate, CB-PAF 85.1%, CB-non-PAF 69.8%; log-rank p<0.001).

Conclusions

For non-PAF patients with PV triggers, PVI with CB might be non-inferior to PVI with RF. Our study showed the efficacy of CB in terms of the shortening of procedural time, and the reduction of radiational exposure. PVI with CB for non-PAF patients was inferior to that for PAF patients.

Identification of an epicardial slow conduction channel using ripple mapping in ablation of postinfarct ventricular tachycardia

An 82-year-old man underwent redo catheter ablation of ventricular tachycardia (VT) after anterior infarction. A ripple mapping conducting channel (RMCC) was identified within the anterior scar in the left ventricular epicardium during sinus rhythm. Along the RMCC, delayed potentials during sinus rhythm, a good pace map with a long stimulus to the QRS interval, and mid-diastolic potentials during VT were recorded, and epicardial ablation at this site eliminated the VT. These findings suggested that the RMCC in the epicardial scar served as a critical isthmus of the postinfarct VT, and ablation targeting the RMCC was effective.

Pulmonary vein isolation plus left atrial posterior wall isolation and additional nonpulmonary vein trigger ablation using high-dose isoproterenol for long-standing persistent atrial fibrillation

BACKGROUND

Little evidence exists regarding the endpoint and optimum approach to catheter ablation for long-standing persistent atrial fibrillation (LSPAF). We examined the efficacy of pulmonary vein isolation (PVI) plus left atrium posterior wall isolation (PWI) and additional non-PV trigger ablation using high-dose isoproterenol for LSPAF.

METHODS

One-hundred and fifty-five patients (median AF duration, 36 months) underwent catheter ablation for LSPAF; After PVI plus PWI, they underwent provocation of non-PV triggers by high-dose isoproterenol and were divided into 3 groups based on the results: group A, PVI plus PWI alone, without induced non-PV triggers (single procedure: 105 patients, multiple procedures: 90 patients); group B, mappable non-PV triggers demonstrated and ablated (single procedure: 41 patients, multiple procedures: 45 patients); group C, if non-PV triggers were unmappable or could not be induced in repeated procedures, adjunctive complex fractionated atrial electrogram ablation was performed (single procedure: 9 patients, multiple procedures: 20 patients).

RESULTS

The Kaplan-Meier estimate of the 1-year freedom from atrial tachyarrhythmias without antiarrhythmic drugs was 65% in all patients, (73%, 56%, and 11% in groups A, B, and C, respectively) after a single procedure, which improved to 86% in all patients (93%, 86%, and 53% in groups A, B, and C, respectively) after multiple procedures.

CONCLUSION

Even for LSPAF, in approximately 60% of patients, non-PV triggers were not elicited, and PVI plus PWI alone achieved good outcomes. Although the inducibility of non-PV triggers was associated with recurrence of atrial tachyarrhythmias, additional non-PV trigger ablation may improve the outcome after multiple procedures.

Resistance exercise enhances cognitive function in mouse

Physical exercise has been shown to increase adult neurogenesis in the hippocampus and to enhance synaptic plasticity. It has been demonstrated that these neuroprotective effects can be observed following aerobic exercise. However, it remains unknown whether plasticity molecules, such as brain-derived neurotrophic factor (BDNF) and cyclic AMP response element-binding protein (CREB), are expressed in the hippocampus following resistance exercise. We applied voluntary progressive-resistance wheel exercise (RE) for 14 days, and measured BDNF and CREB in the hippocampus. The Morris water maze was also performed to estimate learning and memory. Furthermore, we measured RE effects on mammalian target of rapamycin (mTOR) and 70-kDa ribosomal protein S6 kinase (p70S6K) mediating muscle protein synthesis in the soleus. As a result, we found that RE enhanced cognition and elevated BDNF and CREB expressions in the hippocampus. Also, RE activated the mTOR-p70S6K signaling pathway in the soleus. We found that phosphorylated mTOR and p70S6K were significantly positively correlated with BDNF expression. Our results indicated that resistance exercise drove the protein synthesis signaling pathway in the soleus and enhanced hippocampal synaptic plasticity-related molecules. These results suggest the beneficial effects of resistance exercise on cognitive function.

Japanese men have larger areas of visceral adipose tissue than Caucasian men in the same levels of waist circumference in a population-based study

Visceral adipose tissue (VAT) is an independent risk factor for metabolic and cardiovascular disorders. There has been no study that demonstrated different abdominal fat distribution between Asian and Caucasian men. As the Japanese are less obese but more susceptible to metabolic disorders than Caucasians, they may have larger VAT than Caucasians at similar levels of obesity. We compared the abdominal fat distribution of the Japanese (n=239) and Caucasian-American (n=177) men aged 40-49 years in groups stratified by waist circumference in a population-based sample. We obtained computed tomography images and determined areas of VAT and subcutaneous adipose tissue (SAT). We calculated VAT to SAT ratio (VSR). The Japanese men had a larger VAT and VSR in each stratum, despite substantially less obesity overall. In multiethnic studies, difference in abdominal fat distribution should be considered in exploring factors related to obesity.

Relation of the stages of change for exercise behaviors, self-efficacy, decisional-balance, and diet-related psycho-behavioral factors in young Japanese women

BACKGROUND

A large proportion of young Japanese women is inactive. Exercise has important health benefits, however, abnormal weight/eating concerns and excessive dieting practices among physically active young women also have been reported in many cross-sectional studies. The purpose of this study was to examine the relationships between stages of change for exercise behaviors and exercise/dieting related psycho-behavioral factors using the Transtheoretical Model of behavior change as a theoretical framework.

METHODS

A cross-sectional study included 450 young Japanese women aged 18 to 21 (18.4+/-0.67 years). Subjects in precontemplation (n=111, 24.7%), contemplation (n=120, 26.7%), preparation (n=177, 39.3%), action (n=17, 3.8%), and maintenance (n=25, 5.6%) were compared on physique, body composition, current exercise practices, exercise self-efficacy, decisional balance (benefits and costs exercise), as well as dieting behaviors and weight/eating concerns.

RESULTS

Stages of change for exercise behaviors were significantly related to exercise self-efficacy and perceived benefits as well as to dieting behaviors and weight/eating concerns. Subjects in the higher stages had higher self-efficacy, perceived benefits of exercise, and healthy dieting behaviors; however, some of them also had unhealthier dietary practices, higher phobia of obesity and obsession with eating than those in lower stages.

CONCLUSIONS

These findings provide support for applying the transtheoretical model of exercise behavioral change to Japanese young women. Additionally, it is also important to pay attention to stage specific psycho-behavioral factors related to their dieting.

Effects of shift work on 24-hour ambulatory blood pressure and its variability among Japanese workers

OBJECTIVES

This study examined the effects of rotating shift work on blood pressure in a comparison of ambulatory blood pressure and long-term changes in blood pressure between shift and day workers.

METHODS

Ambulatory blood pressure was measured for 24-hour periods at an interval of 30 minutes for 27 shift workers and 26 day workers when they worked during the day. Blood pressure was compared between these 2 groups of workers for 4 time categories (awake, sleep, nonwork awake, and work periods). Their long-term blood pressures, recorded in annual surveys, were reviewed for long-term changes. These comparisons were adjusted for the effects of body mass index, alcohol intake, anger expression, and physical activity.

RESULTS

On the average, sleep time was shorter and the anger-in (ie, anger suppressed) score was higher for the shift workers than for the day workers, but body mass index and alcohol intake did not differ between the 2 groups. Even after adjustment for these co-variables, the mean systolic blood pressure during the 24-hour, awake, and work periods were higher among the shift workers than among the day workers. The 24-hour standard deviations of the systolic blood pressures were also higher for the shift workers than for the day workers. Among the shift workers, but not among the day workers, a significant long-term increase was observed in systolic blood pressure measured in the annual surveys.

CONCLUSIONS

These results suggest that shift work may increase systolic blood pressure levels among Japanese men.

The relationship between physical fitness and coronary risk factor profiles in Japanese women

The purpose of this study was to investigate the relationship between physical fitness and coronary risk factor profiles in Japanese women. The subjects were 1,483 women (ages 30 to 69) who participated in a practical health promotion program. After medical examination, physical fitness was evaluated by conducting a symptom limited maximal exercise test by ergometer to measure maximum oxygen uptake (peakVO(2)) with an expired gas analyzer. The subjects were classified into 3 groups (high fitness, moderate fitness, and low fitness) according to age and physical fitness level. The results showed that the subjects in higher fitness groups had lower levels in: body mass index (BMI), percentage of body fat, waist-hip ratio, resting blood pressure, and atherogenic index, and higher HDL-cholesterol compared to those in lower fitness group. Even after adjustment for the effects of age and BMI, die subjects in the higher fitness groups had better coronary risk factor profiles. These results suggest that among Japanese women a high level of physical fitness is related to favorable coronary risk factor profiles.

The frequencies of diabetic complications in elderly non-insulin dependent diabetic patients in Himeji

Data on 746 patients with non-insulin-dependent diabetes mellitus (NIDDM) were collected from the Internal Medical Association in Himeji by questionnaire, and the patients were divided into six groups according to the duration of illness. Frequencies of various complications according to the duration of illness and risk factors of complications were compared between men and women. Although the number of male patients was 417, significantly more than the 329 female patients, many female patients were elderly, and the age at initial onset was about 10 years older than that of the male patients. Fasting blood sugar and hemoglobin A1c levels increased with the duration of illness. The female patients showed a greater tendency to suffer from hypertension, hyperlipidemia and obesity than the male patients. There was positive correlation between the incidence of complications and duration of illness. This tendency was more marked in the female patients than in the male patients. Both male and female patients showed a tendency for microangiopathy to appear earlier than macroangiopathy. The increase in the frequency of complications accompanying the increase in the duration of illness was more marked for microangiopathy than for macroangiopathy.

The prevalence of diabetic complication of elderly diabetics in Himeji

Diabetes mellitus has recently markedly increased among elderly patient's diseases. There are no recent epidemiological reports on the relative number of male and female diabetic patients. So, an epidemiological study was performed on 746 Non-Insulin-Dependent Diabetes Mellitus patients, whose data were obtained from members of the Himeji Internal Medicine Association, divided into six groups according to sex and duration of illness. The following results were obtained. 1) The number of male patients was greater by about 20% than that of female patients, while elderly patients accounted for a larger proportion, nd age at onset of disease was about ten years higher in female than in male patients. 2) All indicators of diabetes mellitus became worse with longer duration of illness. 3) There was a correlation between the prevalence of complications and the duration of illness: The prevalence of complications increased in parallel with increasing duration of illness, and this tendency was more marked in female than in male patients. 4) Female patients had a more marked tendency to develop hypertension, hyperlipidemia and obesity than male patients. 5) Microangiopathy generally manifested itself earlier than macroangiopathy, and the increase in the prevalence of angiopathy in accordance with prolonged duration of illness was more marked for microangiopathy than for macroangiopathy. Clinical features of Japanese diabetics are found to be similar to those of Europeans, especially dominant in females. This might be due to the changing life style in japan.

[Periodical blood pressure variation during cardiopulmonary bypass--effects of cervicothoracic epidural anesthesia and phentolamine]

We studied the effects of cervicothoracic epidural anesthesia or intravenous phentolamine on periodical blood pressure variation during cardiopulmonary bypass in 12 adult patients undergoing open heart surgery under fentanyl anesthesia. Spontaneous periodical fluctuation of the blood pressure was analyzed by means of autoregressive power spectrum method. Amplitudes of the low frequency (0.02-0.15 Hz) component of the blood pressure variation amplitudes were calculated. The amplitudes decreased significantly 10 minutes after cervicothoracic epidural block with 15 ml of 2% lidocaine solution (P < 0.05), and after infusion of 0.4 mg.kg-1 of phentolamine (P < 0.05). Since amplitudes of the blood pressure variation were reduced by adequate epidural block or phentolamine, they are likely to reflect sympathetic vasomotor activity.

[Renal failure in paroxysmal nocturnal hemoglobinuria]

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired hemolytic disorder characterized by a membrane abnormality of red cells, and characterized by two major clinical features of gross hemoglobinuria and diffuse venous thrombosis. In Japan, the present report records the first case of acute renal failure complicating PNH with treated by hemodialysis and was almost completely reversible.

CASE

A 41 year-old woman was admitted for high fever (39.8 degrees C), dyspnea and clinical signs of a respiratory infection. She was started on Cefotax 1,000 mg 3 times daily. She subsequently developed acute renal failure and which treated by hemodialysis and was almost completely reversible. Following treatment of her renal failure, respiratory infection and anemia, she initially made good progress and was discharged.

[A case of polycystic kidney with bilateral nephrectomy]

A 56-year-old woman in chronic hemodialysis had been suffering from uncontrollable fever for the past 7 months. Her original disease was diagnosed as familial polycystic kidney and three of her five brothers were found to have the same disease. Her chromosome was 46,XX,21P+ and laboratory examination revealed severe anemia, malnutrition, liver dysfunction, pyuria and candidiasis of urine. Abdominal echogram and CT scan revealed polycystic kidneys and multiple liver cysts. She was admitted to our hospital and was diagnosed as having pyelonephritis of the right kidney. As her condition was not improved by conservative therapy right nephrectomy was performed. One month later, spiking fever and left tenderness reappeared. Those symptoms could not be controlled by conservative therapy and left nephrectomy was performed again. Pathological examination on nephrectomized kidneys showed interstitial nephritis, hyaline degeneration and proliferative change of glomeruli, microabscess, colloid of tubules and calcification of parts of Henle's loops. Nephrectomy has been performed in 1.6 to 10.0% of polycystic kidneys due to references since 1952. Eight of the 22 polycystic kidneys (36.3%) seen at our hospital during the past 10 years have been removed.

[Study on changes in plasma platinum concentrations after administration of CDDP to maintenance hemodialysis patients]

Changes in plasma platinum concentration after administration of CDDP were studied in six patients on maintenance hemodialysis with malignancies. Plasma exchange was carried out on three patients for the purpose of plasmapheresis. A therapeutic dose of 51 mg/m2 of CDDP was administered to each patient without any severe adverse reactions. Plasma platinum concentration was measured by atomic absorption spectrophotometry, and the decay curve of the agent showed a biphasic pattern with an initial steep alpha phase and an ensuing mild beta phase in both hemodialysis patients and normal controls. As these patterns showed no renal excretion of CDDP, it was suggested that the uptake of CDDP into tissue was one of the main causes of the steep alpha phase. In patients given plasma exchange one or two hours after the beginning of CDDP administration, the reduction rates of plasma platinum were 74.7-61.7%, but the collection rate of the agent in the exchanged plasma was only 22.2-7.5%. These results indicated that the uptake of CDDP into tissue might occur rapidly within a few hours after CDDP administration.

Clinical reports on plasma exchange in the Kidney Center, Tokai University School of Medicine

There were 72 patients (19 with hepatic failure, 10 with fulminant hepatitis, eight with paraquat poisoning, eight with rheumatoid arthritis, five with myasthenia gravis, four with hyperlipidemia, four with systemic arteriosclerosis including brain infarction, three with pemphigus vulgaris, two with multiple myeloma, two with systemic lupus erythematosus, two cases non-specific Ig-G antibody, two cases medication with an anticancer drug, one with multiple sclerosis, one with Crohn's disease with amyloid kidney and one with chronic myeloblastic leukemia) treated by plasma exchange in the Kidney Center, Tokai University School of Medicine from Jan. 1983 to Dec. 1986. We performed plasma exchange using fresh frozen plasma in 40 cases and Lactate-Ringer's solution containing albumin (4.0-5.0%) in 20 cases as the replacement fluid. In 17 cases, we performed double filtration plasma exchange with the recycle system and no replacement fluid. Although PE therapy did not constitute a basic therapy for hyperlipidemia, pemphigus vulgaris, rheumatoid arthritis, myasthenia gravis, and systemic lupus erythematosus, it was effective in relieving severe clinical symptoms. At the present time, conventional plasma exchange does not improve the survival rate of patients with hepatic failure and fulminant hepatitis. Developments of a new artificial liver support apparatus and identity of many toxic substances in hepatic failure are necessary. No hypotension, hypovolemic shock or other significant complications were experienced.