Extensive ablation strategy for persistent atrial fibrillation impairs left atrial function but reduces recurrence rate

Background

In catheter ablation for persistent atrial fibrillation (AF), extensive ablation strategy, such as linear ablation and/or complex fractionated atrial electrogram (CFAE) ablation in addition to pulmonary vein isolation (PVI-plus), might impair left atrial function more severely than PVI-alone strategy.

Purpose

The aim of this study is to investigate the impact of extensive ablation strategy on LA function and assess the relationship between post-ablation LA function and recurrence.

Methods

This study is a post-hoc subanalysis of the EARNEST-PVI randomized controlled trial, which investigated the efficacy of the PVI-alone strategy in comparison with PVI-plus strategy for persistent AF. From the 497 participants of EARNEST-PVI trial, we enrolled 191 patients with full datasets of pre- and post-ablation cardiac computed tomography (CT) at our Hospital. Patients were divided into PVI-alone and PVI-plus groups. Within one month before and 3 months after ablation, LA volume index (LAVI) and LA emptying fraction (LAEF) were calculated by using the Comprehensive Cardiac Analysis software on the Extended Brilliance Workspace. We assessed i) post-ablation LA function, ii) AF/atrial tachycardia (AT) -free rate after single and final session, and iii) relationship between post-ablation LAEF and ablation success in each group.

Results

The indices of baseline LA remodeling were not different between PVI-alone (N=96) and PVI-plus groups (N=95) [LAVI: 71.4 (57.8, 82.0) vs. 68.7 (61.0, 78.1), P=0.92, LAEF: 13.7 (10.0, 17.4) vs. 13.0 (10.0, 16.9), PVI-alone vs. PVI-plus, P=0.78]. In overall patients, post-ablation LAEF did not differ among them [34.4 (26.1, 40.7) vs. 31.6 (26.0, 37.4), P=0.13]. In the analysis of patients showing sinus rhythm during the CT study, LAEF was significantly higher in PVI-alone (N=87) than in PVI-plus group (N=93) [35.7 (29.0, 41.0) vs. 31.7 (26.1, 37.5), P=0.011] (Figure 1A). AF/AT-free survival rate during median follow-up of 44 months was not different after first session (63.5% vs. 68.4%, P=0.33), while PVI-plus had a tendency towards higher success rate after final session (72.9% vs. 84.2%, P=0.053) (Figure 2). In receiver operating characteristics analysis for recurrence after first session, post-ablation decreased LAEF had significantly related to recurrence after PVI-alone (AUC: 0.733, P<0.0001), but not after PVI-plus (AUC: 0.567, P=0.31) (Figure 1B, C).

Conclusion

Compared with PVI-alone strategy, PVI-plus strategy damaged LA function more severely, but tended to be related to higher success rate. Post-ablation LA function was related to recurrence in PVI-alone, but not in PVI-plus. Extensive ablation might have additional anti-arrhythmic effect regardless of iatrogenic myocardial damage. Myocardial injury by extensive ablation may less attribute to recurrence than intrinsic damage of LA.

Funding Acknowledgement

Type of funding sources: None.

Development of the new risk score to predict occurrence of atrial fibrillation early after acute myocardial infarction

Background/Introduction

New onset of atrial fibrillation (AF) is associated with adverse short- and long-term outcomes after acute myocardial infarction (AMI), and its prediction is relevant for the risk stratification in patients with AMI. Although several risk scores were developed for AF in the general population, there is no established risk score for AF occurrence after AMI.

Purpose

To develop a risk score to predict occurrence of AF early after AMI.

Methods

We enrolled consecutive 751 patients with AMI who admitted to our hospital between April 2006 and September 2012 for the present study. New occurrence of AF was defined as AF detected during hospital stay in a patient showing normal regular sinus rhythm at admission. Parameters relevant to the occurrence of AF was selected from the clinical characteristics, physical status and blood test data at admission, and peak CK/CK-MB, by stepwise logistic regression analysis. We constructed a risk score model to predict the new occurrence of AF, using selected parameters and their logistic regression coefficients. C-statistics was determined by constructing a receiver operating characteristic curve to evaluate the accuracy of the risk score for prediction of AF occurrence.

Results

We excluded 48 patients (6.4%) who had AF at admission, and 208 patients without sufficient data at admission, and thus, the study group consisted of 459 patients (age; 65±13 years, male gender; 79.6%). New AF occurrence was observed in 72 patients (14.5%). The following 7 parameters was selected as parameters related with AF (as p<0.1); Inferior/posterior AMI, use of β blockers, use of diuretics, single vessel disease, absence of reperfusion therapy, systolic blood pressure (sBP) at admission, and smoking. One point was given to sBP>128mmHg, 2 points to absence of reperfusion, and one point to other parameters. Sum of these points was calculated as the AF risk score (Table 1). AF occurred in 27.1% of patients with ≥5 points whereas it was observed 5.2% of those with <5 points. C-statistics of the risk score was 0.75 (95% CI 0.68–0.83).

Conclusion

We developed a novel risk score to estimate the risk of AF occurrence early after AMI, which can be a useful tool for the risk stratification after AMI.

Funding Acknowledgement

Type of funding sources: None.

Untreated sleep apnea and left atrial dilatation in patients with atrial fibrillation prior to catheter ablation

Background

Sleep apnea and left atrial dilatation are both risk factors for an arrhythmia recurrence after catheter ablation (CA) of atrial fibrillation (AF). Negative intrathoracic pressure fluctuations during an obstructive apnea episode may cause the left atrium to distend and stretch its wall. Whether sleep apnea is associated with left atrial dilatation in patients receiving CA of AF remains unknown.

Purpose

We sought to elucidate whether moderate or severe untreated sleep apnea was associated with left atrial dilatation in patients with AF before CA.

Methods

This study was conducted under a retrospective, single-center, observational design. The data were derived from screening tests for sleep apnea, which were routinely performed in patients scheduled to receive CA of AF in our institution. After excluding patients who were already diagnosed with sleep apnea, we enrolled 1265 consecutive patients (age 65±11 years, 27.8% females, and 46.2% of non-paroxysmal AF) who underwent both home sleep apnea testing and multidetector computed tomography (MDCT) before the CA of AF. The severity of the sleep apnea was evaluated by the apnea-hypopnea index (AHI) using a watch-type peripheral arterial tonometry. Left atrial dilatation was evaluated by the left atrial maximum volume (LA max V) using 256-slice MDCT.

Results

The age was 65±11 years, 27.8% were females, and 46.2% had non-paroxysmal AF. The mean AHI was 20.3±15.3 and LA max V 105±34 ml (R2=0.075, p<0.0001). LA dilatation was defined by larger than mean LA max V (LA max V≥105 ml). We examined an LA max V≥105 ml as a predictor. After an adjustment by an advanced age (≥65 years), non-paroxysmal AF, male sex, obesity, hypertension, and congestive heart failure, all of which were significant predictors of an LA max V≥105ml in the univariate analysis, moderate or severe sleep apnea (AHI≥15) was a significant predictor of an LA max V≥105 ml (odds ratio 1.63, 95% confidence interval 1.24–2.14, p=0.0005).

Conclusion

Among the patients scheduled to receive catheter ablation of AF, moderate or severe sleep apnea was independently associated with left atrial dilatation.

Funding Acknowledgement

Type of funding sources: None.

Sex differences in terms of recurrent atrial fibrillation after catheter ablation according to the history of heart failure: insights from the Kansai Plus Atrial Fibrillation (KPAF) registry

Background

There are significant differences in the prevalence and prognosis of cardiovascular diseases between male and female. We previously reported that catheter ablation (CA) of atrial fibrillation (AF) was less effective in female than male, but whether their history of heart failure influence the recurrence after CA of AF remains still unknown.

Purpose

We sought to clarify sex differences in terms of AF recurrence after RFCA of AF according to the history of heart failure.

Methods

We conducted a large-scale, prospective, multicenter, observational study (Kansai Plus Atrial Fibrillation Registry). We enrolled 5010 consecutive patients who underwent an initial RFCA of AF at 26 centers (64±10 years; 1369 [27.3%] females; non-paroxysmal AF, 35.7%). The median follow-up duration was 2.9 years.

Results

Fourteen % of female had a history of heart failure prior to CA, while 12.8% of male had a history of heart failure at baseline (p=0.29). The 3-year cumulative incidence of AF recurrence after a single procedure was 43.3% in female and 39.0% in male (log rank P=0.0046). In patients with the history of heart failure, AF recurrence rates were 42.2% in female and 45.8% in male (log rank P=0.51). On the other hand, in patients without history of heart failure, more females experienced AF recurrence (female vs. male, 43.5% vs. 38.0%, log rank P=0.001).

The rate of AF recurrence after multiple procedures was higher in female (24.2% vs. 19.6%, log rank P<0.0001). AF recurrence rates were similar between sexes in patients with history of heart failure (female vs. male, 26.0% vs. 26.7%, log rank P=0.86), while AF recurrence rates were higher in female without history of heart failure than those in male (females vs. males, 23.9% vs. 18.5%, log rank P<0.0001).

Conclusion

The Kansai Plus Atrial Fibrillation Registry revealed a distinct sex difference in terms of the AF recurrence after CA of AF. Females had higher recurrence rates compared with males in patients without history of heart failure, while recurrence rates were similar between sexes in patients with history of heart failure.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Research Institute for Production Development in Kyoto, Japan.

Association between myocardial wall thickness and left ventricular functional recovery after catheter ablation of atrial fibrillation in patients with reduced ejection fraction

Background

Catheter ablation of atrial fibrillation (AFCA) is an effective treatment to develop left ventricular (LV) functional recovery. However, the degree of recovery differs between individuals due to the different extent of myocardial fibrosis and scarring.

Purpose

To examine whether pre-ablation LV wall thickness (WT) and its regional heterogeneity predict LV functional recovery after AFCA in patients with LV systolic dysfunction.

Methods

Of 3682 consecutive patients who underwent first-time AFCA between January 2012 and September 2020 in our institution, 174 (age, 63±10 years; male, 83%; ischemic cardiomyopathy, 14%) with a baseline LV ejection fraction (LVEF) of <40% were retrospectively evaluated. They were subjected to 256-slice MDCT scanning at baseline and 3 months after AFCA. Baseline WT was evaluated by 16-segment model. Mean and standard deviation (SD) of 16 regional WT were calculated in both end-systolic and end-diastolic phase.

Results

LVEF significantly improved from 30±7% to 57±17% (p<0.001) after AFCA. Increase in LVEF (delta-LVEF) was positively correlated with baseline end-diastolic WT (r=0.31, p<0.001) and negatively correlated with SD of end-systolic WT (r=−0.21, p=0.007). Independent of WT measurements, delta-LVEF was negatively correlated with LV end-diastolic volume (r=−0.42, p<0.001). We created a scoring system to predict the degree of wall motion recovery using the median value of the 3 variables; assigned 1 point each for end-diastolic WT >7.4mm, SD of end-systolic WT <1.61mm, and LV end-diastolic volume <125ml. The model successfully predicted improvement in LVEF after AFCA (0 point (N=13) vs. 1 point (N=72) vs. 2–3 point (N=89), 11±16% vs. 20±17% vs. 33±12%, p<0.001).

Conclusion

Myocardial WT and its regional heterogeneity as well as LV end-diastolic volume predicted functional recovery after AFCA in patients with reduced LVEF.

Funding Acknowledgement

Type of funding sources: None.

The utility of a novel approach to quantify dyssynchrony by multidetector computed tomography

Funding Acknowledgements

Type of funding sources: None.

Background

Quantification of left ventricular (LV) dyssynchrony is of great interest for resynchronization therapy (CRT). Recently, cardiac computed tomography (CCT) is feasible for evaluation of dyssynchrony. Our aim was to assess a novel simplified approach using CCT to quantify LV dyssynchrony.

Methods

We studied 346 consecutive patients with a wide range of QRS width and ejection fractions (EF). Electrocardiogram-gated contrast-enhanced 256-slice multidetector CT (Brilliance 256 iCT, Philips Medical Systems) was performed before CRT. After CCT scan, the LV endocardial boundaries from short-axis images reconstructed at 5% increments of cardiac cycle were automatically detected, and a time from R-wave to maximal wall motion was calculated for each of the 16 standardized segments for all slices using software "Myocardial Contraction Map" (Argus, Inc Ehime, Japan). The standard deviation of all segments modified by mean heart rate (%SD) was respectively calculated as the global parameter of dyssynchrony. LVEF was also measured using MDCT.

Results

%SD was feasible in all patients, respectably. %SD was significantly different between the different QRS duration groups; narrow QRS (<120ms): 9 ± 5%, relatively wide QRS (120-150 ms): 11 ± 6%, and significantly wide QRS (>150 ms): 14 ± 7% (p <0.001). Moreover, there was significantly difference in %SD between the different morphology groups; normal: 9 ± 7%, Non-left bundle branch block (Non-LBBB): 10 ± 6%, LBBB: 17 ± 7% (p <0.001).

Conclusion

This novel simplified approach by CCT can quantify dyssynchrony in different QRS duration and morphology groups. This method has promise for clinical applications to the evaluation of patients for CRT.

Abstract Figure.

29 The effect of vitrification at the immature stage on DNA methylation in porcine oocytes and its relevance to subsequent embryo development

Oocyte vitrification is an important approach for invitro gene banking of female germplasm; however, in pigs, it hampers embryo development. In cattle, vitrification at the MII stage was reported to alter epigenetic status in oocytes and even in subsequently developing embryos (Chen et al. 2016 Theriogenology 86, 868-878). The present study investigated the effect of vitrification at the immature stage of porcine oocytes on DNA methylation status and its relevance to subsequent embryo development. Immature cumulus–oocyte complexes were vitrified in microdrops and warmed (vitrified group) or treated with cryoprotectant agents (17.5% ethylene glycol + 17.5% propylene glycol, CPA group) by our method (Appeltant et al. 2018 Cryobiology 85, 87-94). Then they were subjected to IVM, parthenogenetic activation (PA), and embryo culture. From each batch, a group of oocytes was processed without treatment (control group). Oocyte survival and polar body extrusion were recorded after IVM. Cleavage and blastocyst developmental rates were recorded on Day 2 and 6 of culture, respectively (Day 0=PA). In each replication, DNA methylation was assayed in representative oocytes at the MII stage after IVM and in embryos at the 2- to 4-cell stage on Day 2 by immunostaining with 5-methylcytosine (5mC). Relative fluorescent intensity of 5mC in the chromatin was compared among groups. The experiment was replicated 3 times. Data were analysed by ANOVA. After IVM, there was no significant difference among the control, CPA, and vitrified groups in terms of the percentage of live oocytes (99.3, 96.4, and 94.0%, respectively) or polar body extrusion (88.6, 86.9, and 79.6%, respectively). After PA of oocytes with a polar body, there was no difference between the control and CPA groups in the percentage of cleavage (84.1 and 80.7%, respectively) or blastocyst development of cleaved embryos (63.3 and 79.3%, respectively). However, in the vitrified group, cleavage and blastocyst development rates (46.6 and 33.5%, respectively) were reduced (P<0.05) compared with the other groups. The 5mC fluorescence in the DNA of oocytes at the MII stage in the CPA and vitrified groups were similar and significantly lower than that in the control group (0.88±0.02, 0.87±0.001, and 1.0±0.02, respectively) but higher than that in the negative control processed without primary antibody (0.33±0.02). In the embryos at the 2- to 4-cell stage, 5mC fluorescence was not significantly different among the control, CPA, and vitrified groups (1.0±0.1, 0.99±0.1, and 0.96±0.1, respectively) but was significantly higher than that of the negative control (0.36±0.04). In conclusion, CPA treatment reduced DNA methylation levels in oocytes. However, it was restored during early embryo development and did not affect blastocyst development. The results suggest that reduced DNA methylation in vitrified oocytes is caused by CPA but it may not be responsible for their reduced ability to develop to blastocysts.

30 The importance of cumulus cells for the survival and timing of meiotic resumption of porcine oocytes vitrified at the immature stage

Previous research revealed that vitrification at the immature (the germinal vesicle, GV) stage triggers premature meiotic resumption in cumulus-enclosed porcine oocytes and causes a damage in gap junctions (Appeltant et al. 2017 Reprod. Fertil. Dev. 29, 2419-2429). However, the correlation between the two phenomena was not investigated yet. The present research was conducted to clarify whether premature meiotic resumption is caused by gap junction disruption and to assess the importance of cumulus cells for the survival of porcine oocytes vitrified at the GV stage. Cumulus–oocyte complexes (COCs) were collected from 3- to 6-mm antral follicles of slaughtered gilts. Immediately after collection, approximately half of them were denuded mechanically (DOs). In each replicate, groups of COCs and DOs were processed without vitrification (control groups). Treatment groups of COCs and DOs were vitrified on Cryotop sheets in a combination of 17.5% propylene glycol and 17.5% ethylene glycol and warmed in 0.4M sucrose. The oocytes were then cultured for 22h in a chemically defined porcine oocyte medium (POM) supplemented with 10ngmL−1 epidermal growth factor, 10IUmL−1 equine chorionic gonadotrophin, 10IUmL−1 human chorionic gonadotrophin, and 1mM dibutyryl cAMP. After culture, COCs were denuded and oocyte survival was assessed by morphological evaluation of membrane integrity under a stereo microscope. Then, live oocytes were fixed and stained with 1% orcein and nuclear status was evaluated under a phase-contrast microscope. The experiment was replicated 5 times. Data were analysed by ANOVA followed by Tukey’s multiple comparisons test. After vitrification and culture, the survival rate in the COC group was higher (P<0.05) than that of the DO group (160/191=84.7±3.4% vs. 153/237=65.0±6.2%, respectively) but reduced (P<0.05) compared with those in the control COC and DO groups (138/143=96.6±1.0% and 152/153=99.3±0.6%, respectively). The majority of the control COCs and DOs were at the GV stage with similar percentages (95.6±2.2% and 94.0±2.2%, respectively). In contrast, the percentages of oocytes at the GV stage in the vitrified COC and DO groups were reduced (71.6±9.4% and 45.7±10.5%, respectively; P<0.05) compared with the control groups, which were associated with increased frequencies of diakinesis and MI stages. Percentages of oocytes at the GV stage in the vitrified COC and DO groups were not significantly different (P=0.23). In conclusion, cumulus cells can prevent vitrification-related membrane damage of oocytes. Furthermore, vitrification induced premature meiosis both in the cumulus-enclosed and denuded oocytes even in the presence of the meiotic inhibitor, dibutyryl cAMP. Nevertheless, cumulus removal without vitrification did not induce premature meiosis in the oocytes. Therefore, disruption in communication with cumulus cells might not be the primary reason for premature meiosis in vitrified oocytes.

High incidence of left atrial dysfunction and low voltage zone in patients requiring multiple atrial fibrillation ablation

Background

While multiple catheter ablation for recurrent atrial fibrillation (AF) is effective for the maintenance of sinus rhythm, some of patients have ablation-refractory AF. Left atrial (LA) dysfunction and the presence of low voltage zone (LVZ) are associated with recurrence after AF ablation. The association between recurrence and LA dysfunction/ LVZ among patients undergoing multiple AF ablation remains unclear.

Purpose

We aimed to compare (i)LA function, (ii)the prevalence of LVZ among patients undergoing first, second and third or more AF ablation procedures. Further, we investigated whether LA dysfunction and LVZ are associated with recurrence after multiple procedures.

Methods

We retrospectively analyzed 460 patients undergoing AF ablation procedures including first, second and third or more sessions from January 2017 to October 2019 in our institute. Before each session, 256-slice MDCT was performed under sinus rhythm to measure pre-ablation LA emptying fraction (LAEF) as the representative of LA function. At the end of each session, we checked the presence of LVZ, which was defined as regions where bipolar peak-to-peak voltage was <0.5mV. All patients underwent pulmonary vein isolation (PVI). If necessary, additional ablation (e.g. linear ablation, non-PV foci ablation and LVZ ablation) was performed.

Results

Out of 460 sessions, 295 were first (follow-up years: 1.5 [0.8, 2.0]), 134 were second (1.0 [0.5, 1.8]), and 31 were third or more sessions (1.2 [0.7, 2.0]). As the number of sessions increased, the recurrence rate was increased (19% vs. 31% vs. 61%, first vs. second vs. ≥third, P<0.0001), LAEF decreased (39.7±10.5% vs. 32.6±10.1% vs. 25.3±11.8%, P<0.0001) and the incidence of LVZ increased (18% vs. 34% vs. 68%, P<0.0001) (Figure 1). In patients with recurrence (N=104) after multiple ablation (second or more sessions), LAEF was lower and the prevalence of LVZ was higher than those without recurrence (N=61) (LAEF: 27.3±10.3% vs. 33.5±10.5%, with vs. without, P=0.0003; LVZ: 57% vs. 31%, P=0.0014).

Conclusions

As the number of sessions increased, the recurrence rate was increased. The prevalence of LA dysfunction and LVZ was high in patients requiring multiple ablation procedure. LA dysfunction and LVZ possibly reflect arrhytmogenic substrate causing recurrence of ablation-refractory AF. We should carefully consider repeated AF ablation in patients with severe LA dysfunction and extensive LVZ.

Figure 1

Funding Acknowledgement

Type of funding source: None

Pre-ablation left atrial function predicts the presence of low voltage zone in patients undergoing paroxysmal atrial fibrillation ablation: OLAF-LVZ predictive score

Background

Preoperative left atrial (LA) function is associated with paroxysmal atrial fibrillation (PAF) ablation outcome. The presence of left atrial low voltage zone (LVZ) is also associated with recurrence. We hypothesized that reduced pre-ablation LA function reflects the presence of LVZ.

Purpose

We investigated the association between baseline LA function and the presence of LVZ in patients undergoing initial PAF ablation. Further, we sought to create the new predictive scoring for the presence of LVZ.

Methods

Consecutive 305 patients who underwent LA voltage mapping during initial PAF ablation from January 2017 to October 2019 in our institute were retrospectively analyzed. We performed 256-slice MDCT at baseline. As the representative of LA function, we calculated LA emptying fraction (LAEF), where LAEF = {[(maximum LAV) − (minimum LAV)]/(maximum LAV)} x 100. LVZ was defined as regions where bipolar peak-to-peak voltage was <0.5mV. We performed the univariate and multivariate analysis to assess the association between LAEF and the presence of LVZ. Second, we performed receiver operating characteristic (ROC) analysis for the prediction of LVZ. We combined multivariate predictors and created the predictive scoring for LVZ.

Results

Out of 305 pts, 56 pts (18%) had LVZ in LA. In univariate analysis, low body mass index, higher percentage of female sex, higher age, higher E/e', larger maximum LA volume and lower LAEF (29.3±11.8% vs. 41.2±9.7, P<0.0001) was associated with the presence of LVZ. In multivariate logistic regression analysis, Low LAEF revealed the strongest predictor for LVZ (LAEF; Odds ratio [OR]/10% increase: 0.54, 95% CI: 0.39–0.82, P=0.0016). High age and female sex also remained as the independent predictors (Age; OR/10 y.o. increase: 1.80, 1.23–3.03, P=0.0042, Female; OR: 2.51, 1.15–5.49, P=0.0213). In ROC analysis, LAEF had moderate predictive accuracy for the presence of LVZ. (Area under the ROC curve: 0.77, Best cut-off value: 31%, P<0.0001) (Figure 1). We created OLAF-LVZ predictive score by combining Old age (1 point, ≥65), LAEF (2 points, LAEF ≤31%) and Female sex (1 point). OLAF score had gradient effect on the incidence of LVZ (2%, 11%, 25%, 45%, 71%, OLAF score; 0, 1, 2, 3, 4, respectively, P<0.0001) (Figure 2).

Conclusions

In PAF patients, preoperative LAEF was strongly associated with the presence of LVZ. LVZ might reflect the myocardial injury causing LA dysfunction. OLAF-LVZ predictive score: combination of Old age (≥65), Female sex, and LAEF (≤31%) could be useful to stratify the risk of the presence of LVZ.

Funding Acknowledgement

Type of funding source: None

Quantitative analysis of dyssynchrony assessed by multidetector computed tomography can predict clinical outcome after cardiac resynchronization therapy

Background

The degree of mechanical dyssynchrony has been suggested as a predictor for long-term survival after cardiac resynchronization therapy (CRT). There have been little reports of dyssynchrony assessment with the use of cardiac computed tomography (CCT).

Methods

We studied 35 heart failure (HF) patients (average age 67±10 years) referred for CRT with NYHA III-IV heart failure, left ventricular (LV) ejection fraction (EF) 20±10% (all ≤35%), and QRS duration 156±22 ms (all ≥120ms). Electrocardiogram-gated contrast-enhanced 256-slice multidetector CT was performed before CRT. Based on CCT, the LV endocardial boundaries from short-axis images reconstructed at 5% increments of cardiac cycle were automatically detected, and the time from R-wave to maximal wall motion was calculated for each of the 16 standardized segments for all slices using software “Myocardial Contraction Map”. The standard deviation modified by mean heart rate (%SD) was respectively calculated as the global parameter of dyssynchrony. LVEF was also measured using MDCT. The predefined primary end-point was the first HF hospitalization or death over 2 years.

Results

%SD was feasible in all patients, respectably. There were 16 events over 2 years; 11 HF hospitalizations and 5 deaths. Patients with %SD ≥22% (optimal cutoff for outcome by ROC curve analysis) had a better clinical outcome than patients with %SD <22% (p=0.01, Figure).

Conclusion

Patients who had %SD ≥22% assessed by MDCT had a particularly favorable event-free survival following CRT, and this appears to be an important prognostic marker.

Funding Acknowledgement

Type of funding source: None

Evaluation of the local atrial function by regional speckle tracking imaging using intracardiac echocardiography

Background

It has been reported that low voltage areas and conduction abnormalities detected by electrophysiology catheters in the left atrium (LA) represent regional degeneration and fibrosis of the atrium and are related to a poor atrial fibrillation (AF) ablation outcome. Assessment of the local atrial function is clinically useful because atrial degeneration does not occur uniformly throughout the atrium. Though evaluating the global atrial function using speckle tracking imaging (STI) by transthoracic echocardiography (TTE) has been attempted, TTE does not have a sufficient image quality to assess local atrial STI.

Purpose

To evaluate the local atrial function by STI using intracardiac echocardiography (ICE) and to elucidate the characteristics of the STI in normal and abnormal voltage regions in the LA.

Methods

We included 9 patients undergoing AF ablation with written informed consent for this prospective observational study. After pulmonary vein isolation, we performed voltage mapping of the LA in sinus rhythm using a CARTO system (Biosense). Abnormal regions and normal regions were defined as those with low voltage areas (<0.5 mV) and those with normal voltages, respectively. Echo images were recorded by an ACUSON SC2000 (Siemens) and SOUNDSTAR catheter (Biosense). We inserted the SOUNDSTAR catheter into the LA to obtain clear images, recorded the STI of the anterior and inferior wall, and performed an offline analysis of the atrial strain with an eSie VVI work station (Siemens) and the LA voltage data with CARTO system at each site simultaneously (left figure). We compared the strain during the atrial contraction phase (Sct) between the normal and abnormal regions.

Results

Among the study population, 5 patients had low voltage areas in the LA. We evaluated the STI at 26 normal regions and 44 abnormal regions. The typical regional speckle tracking waveform in the normal region was similar to a jugular vein pressure waveform (right figure). There was a difference in the amplitude of the Sct between the groups; it was significantly smaller in the abnormal regions (normal and abnormal regions, 9.8±5.0% and 5.6±3.8%, p=0.0001). The duration of the Sct was significantly more prolonged in the abnormal regions than normal regions (98.8±26.3ms and 118.2±33.9ms, p=0.015).

Conclusions

This pilot study demonstrated that the local atrial function was evaluable by STI using ICE and that the regional strain tracking waveform during the atrial contraction phase in abnormal voltage regions was smaller and more prolonged than that in normal regions. An evaluation of the regional STI with an ICE may be useful to detect regional abnormalities of the atrium.

Representative case

Funding Acknowledgement

Type of funding source: None

Screening for obstructive sleep apnea in atrial fibrillation patients at their home before catheter ablation using watch peripheral arterial tonometry

Background

Catheter ablation of atrial fibrillation (AF) is effective, but certain patients experience AF recurrences. Obstructive sleep apnea (OSA) is a risk factor for AF recurrence. Watch peripheral arterial tonometry (WP) has a good correlation with polysomnography (PSG) in terms of the apnea-hypopnea index (AHI) and is easier to perform than PSG. Patients in AF have a high prevalence of OSA. Whether all patients with AF should be evaluated for OSA before catheter ablation is still controversial.

Purpose

To elucidate the prevalence and predictors of OSA using WP as a home sleep apnea test in AF patients before catheter ablation.

Methods

This study was conducted under a retrospective, single-center, observational design. Patients who received AF ablation without a prior diagnosis of sleep apnea and assessment of their AHI using WP were included in this analysis. The patients were mounted with a WP device by themselves at their own home. Twenty-two patients who were already diagnosed with OSA were excluded.

Results

Seven hundred seventy-four (65±11 years, 567 males, 440 paroxysmal AF) out of 776 patients were successfully mounted with WP devices on their own and underwent an OSA assessment. Their mean body mass index (BMI) was 24.1±3.5 kg/m2. The mean AHI was 20.1±15.6. Only 88 (11.4%) patients had a normal AHI (AHI<5). Mild OSA (5≤AHI<15), moderate OSA (15≤AHI<30), and severe OSA (AHI≥30) were observed in 274 (35.4%), 252 (32.6%), and 160 (20.7%) patients, respectively. A BMI≥25 (odds ratio [OR]; 2.42, 95% confidence interval [CI]; 1.74–3.37, p<0.001), male sex (1.70, 1.19–2.44, p=0.0037), non-paroxysmal AF (1.90, 1.35–2.66, p=0.0002), hypertension (1.70, 1.24–2.33, p=0.009), and left atrial volume index ≥30 (OR=1.51, CI 1.06–2.16, p=0.022) were significant predictors of moderate or severe OSA by a multivariate analysis, while an Epworth sleepiness scale ≥11 was not a predictor of moderate or severe OSA (OR=0.99, CI 0.66–1.49, p=0.95). However, 44.2% of non-obese patients (BMI <25) had moderate-severe OSA.

Conclusion Almost

All patients successfully underwent WP to diagnose OSA. AF patients had a high prevalence of OSA, and screening OSA would be important in AF patients receiving ablation even if patients do not have sleepiness or are obese. We cannot deny OSA in AF patients before catheter ablation without performing screening tests for OSA.

Funding Acknowledgement

Type of funding source: None

1677 Global longitudinal strain during dobutamine stress echocardiography can predict left ventricular remodeling after anterior wall acute myocardial infarction

Background

Although dobutamine stress echocardiography (DSE) at the early stage of acute myocardial infarction (AMI) is useful for the prediction of functional and clinical prognosis, the interpretation requires expertise. In this study, we sought to investigate if global longitudinal strain (GLS) during DSE after AMI can predict left ventricular remodeling (LVR).

Methods

Consecutive 30 patients with anterior wall AMI (18 male, age = 58 ± 13 years) were performed DSE 3 days after AMI. GLS was calculated as an averaged value of peak longitudinal strain in the apical 4- and 2-chamber views at baseline echocardiography, low-dose DSE (10 μg/kg/min) using available software (QLAB, Philips Medical Systems). Left ventricular remodeling (LVR) was defined as an echocardiographically determined increase in both EDVI and ESVI of 20% or more from baseline to the 6 month follow-up echocardiography.

Results

12 patients (40%) evolved with LVR. The change in GLS during low-dose DSE was significantly different between the remodeling and non-remodeling group (8 ± 5% v.s. 27 ± 20%, p < 0.05). Interestingly, it predicted LVR with sensitivity of 88%, specificity of 92% at the cut-off value of 12% (Area under the curve = 0.94, p < 0.0001).

Conclusion

The change in GLS during low-dose DSE can be used as a predictor for the LVR after AMI. This observation has promise for clinical applications.

Abstract 1677 Figure.

P5652Catheter ablation outcome and heart failure hospitalization in atrial fibrillation patients with preserved left ventricular ejection fraction: insights from the Kansai plus atrial fibrillation (KPAF)

Background

Heart failure (HF) is the leading cause of death in patients with atrial fibrillation (AF), and AF is an independent prognostic factor in HF patients with preserved left ventricular ejection fraction (LVEF). Radiofrequency catheter ablation (RFCA) for AF is effective to maintain sinus rhythm.

Purpose

We sought to clarify incidence of HF hospitalization and whether AF ablation outcome influenced incidence of HF hospitalization after the procedures in patients with preserved LVEF.

Methods

We conducted a large-scale, prospective, multicenter, observational study. A total of 4522 consecutive patients with normal LVEF (>/- 50%) who underwent an initial RFCA for AF in 26 centers were enrolled (average age, 64±10 years; non-paroxysmal AF, 33.7%). The median follow-up duration was 2.9 years.

Results

The 3-year cumulative incidence of AF recurrence after a single procedure was 40.3%. Hospitalization for HF was observed in 60 patients (1.3%) and was significantly higher in patients with AF recurrence than those without it (2.63% vs 0.44%, log-rank p<0.001). After adjustment by age ≥65 years, estimated glomerular filtration rate ≤60ml/min, history of HF, and female, all of which were statistically associated with a risk of HF hospitalization, AF recurrence after the index RFCA was an independent predictor of HF hospitalization (hazard ratio; 4.75, 95% confidence interval; 2.59–9.42, p<0.001).

Conclusions

Recurrence after RFCA for AF was a significant risk of HF hospitalization among AF patients with preserved LVEF.

Acknowledgement/Funding

This study was supported by the Research Institute for Production Development in Kyoto, Japan.

P1029Catheter ablation outcome and heart failure hospitalization in atrial fibrillation patients: insights from the Kansai plus atrial fibrillation (KPAF) registry

Background

Heart failure (HF) is the leading cause of death in patients with atrial fibrillation (AF). Radiofrequency catheter ablation (RFCA) for AF is effective to maintain sinus rhythm.

Purpose

We sought to clarify whether AF ablation outcome influenced incidence of HF hospitalization after the procedures.

Methods

We conducted a large-scale, prospective, multicenter, observational study. A total of 5010 consecutive patients who underwent an initial RFCA for AF in 26 centers were enrolled (average age, 64±10 years; non-paroxysmal AF, 35.6%). The median follow-up duration was 2.9 years.

Results

The 3-year cumulative incidence of AF recurrence after a single procedure was 40.2%. The 3-year incidence of hospitalization for HF was observed in 92 patients (1.8%) and was significantly higher in patients with AF recurrence than those without it (3.3% vs 0.84%, log-rank p<0.001). After adjustment by advanced age,(≥65 years), reduced left ventricular ejection fraction (≤50%), low estimated glomerular filtration rate (≤60ml/min), and history of HF, all of which were statistically associated with a risk of HF hospitalization (p<0.1, respectively), AF recurrence after the index RFCA was an independent predictor of HF hospitalization (hazard ratio [HR]; 3.17, 95% confidence interval [CI]; 2.06–5.04, p<0.001).Even after multiple procedures (1425 re-ablation sessions in 1274 patients [25.4%]), AF recurrence after the last procedure was an independent predictor of HF hospitalization (HR; 2.83, 95% CI; 1.89–4.24, p<0.001).

Conclusions

Among AF patients receiving RFCA, those with AF recurrence were at greater risk of heart failure hospitalization than were patients without AF recurrence. These differences should be noted when treating AF patients in actual clinical practice.

Acknowledgement/Funding

This study was supported by the Research Institute for Production Development in Kyoto, Japan.

P980Post-procedural plasma brain natriuretic peptide level early after catheter ablation predicts the future clinical outcome in patients with persistent atrial fibrillation and reduced ejection fraction

Background

Successful restoration of sinus rhythm (SR) by catheter ablation (CA) for persistent atrial fibrillation (AF) improves cardiac function, resulting in decrease of plasma brain natriuretic peptide (BNP) level. The exact significance and prognostic implications of this change have yet to be determined.

Purpose

To examine the impact of pre- and post-procedural BNP level on the clinical outcome after CA in patients with persistent AF and reduced left ventricular ejection fraction (LVEF).

Methods

Out of 242 patients with LVEF <50% who underwent first-time CA for persistent AF between March 2012 and September 2018 at our institute, we enrolled 137 patients (61±10 years, 83% male) whose plasma BNP level was available both at baseline and early after CA (during 1–3 month). We evaluated the impact of the BNP levels on future AF recurrence 3 months after CA as the primary endpoint. Additional secondary endpoints included heart failure (HF) hospitalization and cardiovascular death.

Results

All patients successfully restored SR at the end of CA. Within 3 months of a blanking period (BP), improvement of LVEF (from 39±10% to 65±12%, p<0.001) and reduction of BNP levels (from 178 [107–332] pg/ml to 42.3 [21.1–78.6] pg/ml, p<0.001) were observed. During the median follow-up of 21 months after BP, the incidence of AF recurrence, HF hospitalization, and cardiovascular death was 37% (n=50), 3% (n=4), and 1% (n=1), respectively. Cox proportional hazard regression analysis after adjustment for age and gender revealed that post-procedural BNP level was a significant predictor of the AF recurrence (hazard ratio [HR] per 100-pg/ml increase, 1.13; 95% confidence interval [CI], 1.02–1.25; p=0.023), but pre-procedural BNP level was not (1.02; 0.95–1.09; p=0.56). Receiver operating curve analysis determined the post-procedural BNP level of 55.5 pg/ml as the best cut-off value for predicting the AF recurrence, with area under the curve of 0.620 (95% CI, 0.534–0.702; p=0.018). The incidence of AF recurrence was significantly higher in patients with post-procedural BNP level >55.5 pg/ml (n=50) than the others (50% vs. 29%; HR, 3.99; 95% CI, 2.07–7.68; p<0.001). No patients with post-procedural BNP level ≤55.5 pg/ml experienced HF hospitalization and cardiovascular death (8% vs. 0% and 2% vs. 0%, p=0.006 and p=0.17, respectively)

Conclusions

Not pre-procedural but post-procedural BNP level early after CA predicted the future clinical outcome in patients with persistent AF and reduced LVEF. Decreased but still elevated BNP level after restoration of SR would identify the residual risk for developing unfavorable outcome.

129 Embryo Production from Fully Grown and Growing Stage Oocytes in Japanese Black Calves

Before fattening of Japanese Black female calves, the ovaries are sometimes removed and discarded. Production of embryos from the oocytes residing in such ovaries is beneficial for the rescue of genetic resources. The aim of this study was to establish an embryo production system using oocytes collected from the ovaries of calves just before fattening and to investigate the correlation between the developmental competence of oocytes and the onset of puberty. Ovaries were collected from Japanese Black calves (9.5 ± 0.1 months old, n = 30, 3 replicates) in a fattening farm and separated according to the presence or absence of corpus luteum as the indicator of puberty (CL+ and CL– groups, respectively). Immature fully grown oocytes (IM oocytes), ~120 μm in diameter, were aspirated from follicles of 2 to 6 mm in diameter (CL+; n = 132, CL–; n = 41) and cultured for 22 to 23 h for maturation (IVM). After in vitro fertilization (IVF) for 6 h (designated Day 0), the oocytes were cultured for 9 days (in vitro culture, IVC) (Matoba et al. 2014 J. Dairy Sci. 97, 743-753). Growing oocytes, ~100 μm in diameter, were also collected by dissecting the follicles smaller than 1 mm in diameter. The growing oocytes were cultured for 14 days on membrane inserts for in vitro growth (IVG) (Hirao et al. 2013 Biol. Reprod. 89, 1-11). Then, IVG oocytes (CL+; n = 29, CL–; n = 32) were subjected to IVM, IVF, and IVC. Presumptive zygotes were cultured individually in microwells in culture dishes. Mitochondrial DNA (mtDNA) copy numbers (COX1 gene) of oocytes were examined (Takeda et al. 2010 Mitochondrion 10, 137-142). A comparison was made between the oocytes derived from calf ovaries and those of oocytes collected from cow ovaries by transvaginal ovum pick-up or by aspiration of the ovaries obtained at a local slaughterhouse. In IM oocytes, the rate of embryos developed to the blastocyst stage on Day 7 to 9 was higher in the CL+ group than in the CL– group (38.9 ± 2.6 v. 10.0 ± 7.1%, respectively; P < 0.05, t-test). However, IVG oocytes were compared, there was no significant difference in the blastocyst formation rate between the CL+ or CL– groups (34.7 ± 5.2 v. 19.8 ± 10.1%, respectively). The mtDNA copy numbers of matured oocytes were similar between IM and IVG oocytes irrespective of the maturity of the donor animals. In conclusion, we demonstrated the possibility of embryo production by IVM/IVF/IVC using fully grown and growing oocytes that are present in the ovaries of calves before fattening. Puberty positively affected the developmental competence of IM oocytes but the effect was not significant in IVG oocytes. Utilisation of both fully grown oocytes and growing oocytes may double the chance of rescuing genetic resources of high-breeding-value calves. This study was partly supported by grants from the Ito Foundation. We thank staff at Mie-Katoubokujou for allowing access to calves’ ovaries.

Randomised phase III study of neoadjuvant chemotherapy with methotrexate, doxorubicin, vinblastine and cisplatin followed by radical cystectomy compared with radical cystectomy alone for muscle-invasive bladder cancer: Japan Clinical Oncology Group Study JCOG0209

BACKGROUND

This study aimed to determine the clinical benefit of neoadjuvant methotrexate, doxorubicin, vinblastine, and cisplatin (MVAC) in patients with muscle-invasive bladder cancer (MIBC) treated with radical cystectomy.

PATIENTS AND METHODS

Patients with MIBC (T2-4aN0M0) were randomised to receive two cycles of neoadjuvant MVAC followed by radical cystectomy (NAC arm) or radical cystectomy alone (RC arm). The primary end point was overall survival (OS). Secondary end points were progression-free survival, surgery-related complications, adverse events during chemotherapy, proportion with no residual tumour in the cystectomy specimens, and quality of life. To detect an improvement in 5-year OS from 45% in the RC arm to 57% in the NAC arm with 80% power, 176 events were required per arm.

RESULTS

Patients (N = 130) were randomly assigned to the RC arm (N = 66) and the NAC arm (N = 64). The patient registration was terminated before reaching the initially planned number of patients because of slow accrual. At the second interim analysis just after the early stoppage of patient accrual, the Data and Safety Monitoring Committee recommended early publication of the results because the trial did not have enough power to draw a confirmatory conclusion. OS of the NAC arm was better than that of the RC arm, although the difference was not statistically significant [hazard ratio 0.65, multiplicity adjusted 99.99% confidence interval 0.19-2.18, one-sided P = 0.07]. In the NAC arm and the RC arm, 34% and 9% of the patients had pT0, respectively (P < 0.01). In subgroup analyses, OS in almost all subgroups was in favour of NAC.

CONCLUSIONS

This trial showed a significantly increased pT0 proportion and favourable OS of patients who received neoadjuvant MVAC. NAC with MVAC can still be considered promising as a standard treatment.

UMIN CLINICAL TRIALS REGISTRY IDENTIFIER

C000000093.

157 LEUKEMIA INHIBITORY FACTOR IMPROVES OOCYTE MATURATION AND DEVELOPMENTAL COMPETENCE IN PIGS

A variety of growth factors and cytokines that are present in follicular fluid provide oocytes with a suitable environment for their maturation. One such cytokine is leukemia inhibitory factor (LIF). Although LIF-supplemented medium enhances embryo development in human, mouse, and bovine, studies investigating the effects of LIF on in vitro maturation (IVM) and subsequent embryo development are inconclusive. Additionally, the underlying mechanisms of LIF in oocyte maturation and embryo development after IVF have not been studied yet. In the present study, we examined the effect of recombinant porcine LIF (pLIF), produced in our laboratory, on porcine oocyte maturation and the mechanism of how LIF involves in oocyte maturation process at molecular level. The biological activity of pLIF was evaluated by sustenance of mouse embryonic stem (ES) cells with an undifferentiating state in ES medium supplemented with pLIF, and the final concentration (1 : 200, equivalent to 1000 U mL–1 of mouse LIF) was determined by serial dilution. Porcine cumulus–oocyte complexes (COC) were cultured in modified NCSU-37 medium supplemented with pLIF during the first 22 h [pLIF (+, –)], the latter 22 h [pLIF (–, +)], or whole 44 h [pLIF (+, +)] of IVM and the proportion of metaphase II (M-II) stage oocytes was observed. Oocyte maturation was enhanced in each group by supplementation with pLIF [pLIF (+, –): 76.1%, n = 138; pLIF (–, +): 82.1%, n = 140; pLIF (+, +): 86.6%, n = 127], when compared with control [pLIF (–, –): 69.6%, n = 112], in which a significant increase of M-II rate (P < 0.05 by ANOVA) and cumulus expansion were observed in the pLIF (+, +) group. The effect of pLIF was only seen for COC but not for denuded oocytes. When oocytes were subjected to IVF (Kikuchi et al. 2002), those matured in pLIF (+, +)-supplemented medium demonstrated higher blastocyst developmental rates (21.1% v. 16.2%; P = 0.07) with increased cell numbers (50.2 cells v. 45.0 cells; P = 0.12) compared with pLIF (–, –) on Day 6 of embryo culture (IVF = 0). Examination of transcripts and proteins of the LIF signalling pathway revealed that mRNA and protein levels of LIF, LIF receptors, and signal transducer and activator of transcription 3 (STAT3) were similar in both pLIF (–, –) and pLIF (+, +) samples. However, notable phosphorylation of STAT3 was observed in the pLIF (+, +) sample. These results suggest that the LIF/STAT3-pathway is functional during oocyte maturation in pigs. Therefore, supplementation of maturation medium with pLIF could improve the developmental competence of oocytes by activation of this pathway. This project was supported by JSPS and HAS under the Japan-Hungary Research Cooperative Program.

47 DIFFERENCES IN MITOCHONDRIAL DNA COPY NUMBER AND EPIGENETIC PATTERNS OF MITOCHONDRIA-RELATED GENES IN CLONED COWS FROM THE SAME DONOR CELLS

The genetic codes of cloned animals and the donor are identical; however, incomplete reprogramming of donor nuclei during NT causes epigenetic abnormalities in cloned animals. Due to the genetic identity and epigenetic differences among clones, we can study epigenetic effects on the phenotypes by analyzing genetically identical clones. During the NT process, donor cell mitochondria (mt) are transferred into the recipient oocytes and mtDNA heteroplasmy is observed. Previous studies have reported various mtDNA transmission patterns not only in the cloned animal itself but also in the offspring of clones. However, differences in mtDNA copy number in cloned animals have not been reported, especially genetically identical ones. To analyze the genetic effects on mtDNA copy number in cattle, we compared actual mtDNA copy number per diploid genome in various tissues of clones derived from the same donor cells. From 5 genetically identical cloned cows (Japanese Black cattle, ages 68 to 82 months) and 6 non-cloned cows (Japanese Black cattle, ages 52 to 129 months), we isolated DNA from 8 kinds of tissues (heart, lung, liver, kidney, spleen, small intestine, muscle, and spinal cord) and measured mtDNA copy number by using real-time PCR. The absolute copy numbers of 2 mtDNA-encoded genes (COX1 and CytB) and 2 nuclear-encoded genes (H19 and IGF2) were measured and analyzed. To examine the epigenetic effects on mitochondria-related genes, we also analyzed DNA methylation patterns of mitochondria-related gene ANT4 (mitochondrial ADP-ATP translocase) in these tissues by the combined bisulfite restriction analysis (COBRA) method. The actual mtDNA copy number per diploid genome varied in tissues and individuals both in clones and non-clones (average in clones v. non-clones: heart: 11 839 ± 6210 v. 9569 ± 2555; lung: 2027 ± 1153 v. 1383 ± 173; liver: 5644 ± 2278 v. 4799 ± 1848; spleen: 1080 ± 844 v. 393 ± 265; kidney: 7034 ± 4448 v. 2939 ± 784; small intestine: 1330 ± 573 v. 437 ± 171; muscle: 9861 ± 3640 v. 7907 ± 3229; spinal cord: 3961 ± 1819 v. 2756 ± 496). The variability of mtDNA copy number in clones was significantly higher in the lung, spleen, kidney, small intestine, and spinal cord (P = 0.001, 0.026, 0.005, 0.021, and 0.014, respectively; F-test), but not in other tissues. Methylation of the ANT4 gene is quite tissue dependent: hypomethylated in the liver, muscle and spinal cord; moderately methylated in the heart, lung, and kidney; and highly methylated in the spleen and small intestine. The methylation patters of ANT4 were not different between clones and non-clones. These results suggest that mtDNA copy number is more influenced by nongenetic factors than genetic background.

299 A FEATURE OF SELF-RENEWAL PORCINE EMBRYONIC STEM CELL-LIKE CELL LINES ESTABLISHED BY INHIBITORS

Despite meticulous attempts for more than two decades, establishment of authentic porcine embryonic stem cell (ESC) from pig has never been successful. Although putative porcine ESC-like cells have been reported, such cell lines easily lose the ability of self-renewal, becoming extinct or differentiating after only a limited number of passages in culture. Porcine ESC-like cells exhibiting the property of self-renewal rather than pluripotency are considered a valuable resource in applications such as drug screening and toxicology testing in humans and livestock, and in veterinary medicine. In the present study, we evaluated the effect of glycogen synthase kinase 3β (GSK3β) inhibitor CHIR99021 and Erk signalling inhibitor PD184352 for use in establishing ESC-like cell lines derived from the inner cell mass (ICM) of porcine blastocysts produced in vitro. These ICM-derived cell lines were initially cultured and passaged in conventional human ES medium. They displayed so-called ESC-like morphology; for example, the isolated colonies began to grow as a monolayer with coarse cell–cell boundaries, in which the cells exhibited polygonal boundaries, high nuclear/cytoplasmic ratios, abundant lipid-like inclusions, alkaline phosphatase activity, and expression of markers of undifferentiated cells such as OCT4 and NANOG. After transfer to culture in ES medium containing the inhibitors, the morphology of the colony was dramatically changed, displaying a closely packed and smooth-edged colony with tight cell–cell boundaries. Remarkably, growth of the established cell lines is leukemia inhibitory factor (LIF)-dependent. The inclusion of inhibitors supports self-renewal, thus enabling continuous culture for over 100 passages while maintaining an undifferentiated state. High-passage-number cells continued to express undifferentiated marker genes and showed alkaline phosphatase activity and telomerase activity with an X chromosome status of XaXi. We further investigated the potential for differentiation of the established cell lines. The cells could easily form embryoid body-like spheres in suspension culture. When either the spheres or ESC-like cells were inoculated under the kidney or testis capsules of nude mice, classical teratoma formation was not observed after 2 to 3 months. However, histological analyses revealed apparent invasive proliferation derived from porcine cells. Although further analyses are required to characterise the property of the porcine ESC-like cells, we have recently succeeded in establishment of green fluorescent protein (GFP)-expressing stable cells lines, which will be useful for further investigation.

79 A COMBINATION OF ETHYLENE GLYCOL AND PROPYLENE GLYCOL IS SUPERIOR TO INDIVIDUAL CRYOPROTECTANTS FOR THE VITRIFICATION OF IMMATURE PORCINE OOCYTES

We compared the feasibility of ethylene glycol (EG) and propylene glycol (PG) for the vitrification of immature porcine cumulus–oocyte complexes (COC). Porcine COC collected from 3- to 6-mm follicles of slaughterhouse-derived ovaries were subjected to solid-surface vitrification (Somfai et al. 2010 Theriogenology 73, 147–156) either in 35% (v/v) EG or 35% (v/v) PG or in the mixture of 17.5% (v/v) EG and 17.5% (v/v) PG. After warming, the COC were subjected to in vitro maturation, IVF, and embryo culture according to Kikuchi et al. (2002 Biol. Reprod. 66, 1033–1041). Oocyte survival and maturation rates were assessed after in vitro maturation by evaluating membrane integrity and the extrusion of the first polar body. All live oocytes were subjected to IVF and in vitro culture. Cleavage and blastocyst rates were calculated from the total number of oocytes subjected to IVF on Day 2 (Day 0 = IVF) and Day 7, respectively. Total-cell (blastomeres) numbers in blastocysts were recorded on Day 7 after staining with Hoechst 33342. In Experiment 1, competence parameters of oocytes vitrified either in EG-based (EG group; n = 310) or a PG-based (PG group; n = 265) vitrification media were compared with those in the nonvitrified control (n = 160). The experiment was replicated 4 times. In Experiment 2, the competence parameters of oocytes vitrified with the combination of 17.5% EG and 17.5% PG (EG+PG group; n = 397) were compared with those in nonvitrified control (n = 245) and toxicity control (TC, exposed to cryoprotectants without cooling; n = 245) groups. Five replications were performed. Results were analyzed by ANOVA. Differences with P < 0.05 were considered significant. In Experiment 1, the mean survival rate of vitrified oocytes was significantly higher (P < 0.05) in 35% PG compared with that in 35% EG (73.3 and 25.9%, respectively). Maturation rates of surviving oocytes did not differ among vitrified (PG and EG) and nonvitrified control groups (71.1, 62.4, and 64.0%, respectively). After IVF of surviving oocytes, blastocyst formation rate in the group vitrified in EG was higher (P < 0.05) compared with that vitrified in PG but was lower (P < 0.05) compared with control (10.8, 2.0, and 25.0%, respectively). Mean cell numbers in blastocysts did not differ among EG, PG, and control groups (50.5, 47.7, and 48.7, respectively). In Experiment 2, survival of immature oocytes in the EG+PG group was 42.6%. After IVF, 10.7% of oocytes developed to the blastocyst stage in the EG+PG group, which was lower (P < 0.05) than those of the control (18.1%) and TC (23.3%) groups. Blastocyst rates in the control and TC groups were not statistically different. Mean cell numbers in blastocysts did not differ significantly among the EG+PG, control, and TC groups (61.6, 59.3, and 53.3, respectively). In conclusion, 35% PG provided a higher oocyte survival rate after vitrification compared with 35% EG. However, presumably due to toxic effects, 35% PG greatly reduced the development competence of oocytes. The combination of 17.5% EG and 17.5% PG yielded higher survival rates than did 35% EG, without any toxic effect on oocytes.

186 EFFECT OF POLYVINYLPYRROLIDONE SUPPLEMENTATION IN CULTURE MEDIUM ON THE GROWTH OF MOUSE OOCYTES

A high volume of polyvinylpyrrolidone (PVP) supplementation in culture medium has a significant impact on the growth of bovine oocytes. The objective of the present study was to determine whether or not PVP affects oocyte growth in the mouse. Oocyte–granulosa cell complexes were isolated from 11- or 12-day-old mice (ICR) by mechanical isolation of follicles, followed by a collagenase treatment (0.1%; 10 min). Twenty complexes were placed on each insert fit in the 24-well culture plate and cultured for 10 days in an atmosphere of 5% CO2 in air at 37°C. The culture medium was a modified α-MEM supplemented with 5% fetal bovine serum and 1 ng mL–1 FSH. The concentration of PVP (molecular weight of 360 000) was 0%, 1%, 2%, or 3% (w/v). During the first 2 days, only medium with 0% PVP was used. The oocytes recovered on Day 10 were subjected to in vitro maturation, IVF, and embryo culture. In 12 replications, the total numbers of oocytes cultured in medium with 0%, 1%, 2%, and 3% PVP were 235, 233, 233, and 231, respectively. In some additional experiments, oocytes were fixed on Day 10 and processed for transmission electron microscopy (TEM). The oocytes in medium with 0% PVP became located within an enlarged dome-like structure. In medium with 2% PVP and 3% PVP, no such domes were formed, and the oocytes within several granulosa cell layers were exposed to medium; however, the cumulus cell mass specifically became larger than that in medium with 0% PVP. The viabilities of oocytes recovered from medium with 0%, 1%, 2%, and 3% PVP were 83%, 81%, 91%, and 93%, respectively. The survival rate was significantly higher in medium with 3% PVP than in medium with 0% PVP or 1% PVP (P < 0.05). The mean oocyte diameter increased from 59 µm (Day 0) to 72, 71, 71, and 72 µm in medium with 0, 1, 2, and 3% PVP, respectively, but they continued to be smaller than in vivo grown oocytes (81.0 µm; P < 0.01). When maturation was induced, cumulus cell mucification occurred irrespective of PVP concentration during the growth. No significant differences were found between the groups in the percentage of polar body extrusion (ranging from 78 to 88%). Developmental outcomes based on oocytes used for in vitro fertilization were the following: cleavage rates were 67, 78, 74, and 76%; and blastocyst rates were 37, 44, 47, and 36% of oocytes that had been grown in medium with 0, 1, 2, and 3% PVP, respectively. The numbers of oocytes included were 60, 59, 68, and 66, respectively. The TEM observation suggests that more intimate contacts were maintained between the oocyte and cumulus cells in medium with 2% PVP than in medium with 0% PVP. Taken together, PVP supplementation in medium has a considerable influence on the morphology of mouse oocyte–granulosa cell complexes and close contacts within the complexes in the long-term culture, as having been observed with bovine oocytes.

Prognostic significance of CD45RO+ memory T cells in renal cell carcinoma

Background:

Memory T cells are well known to have a critical role for host defense in humans. However, their role in actual human cancer remains largely unknown. In this study, we tried to reveal the clinical importance of tumour-infiltrating CD45RO+ memory T cells in renal cell carcinoma (RCC).

Methods:

We analysed 105 patients with RCC, who received radical or partial nephrectomy. Those were 65 in TNM stage I, 7 in stage II, 15 in stage III, and 18 in stage IV, respectively. CD45RO expression was evaluated by immunohistochemistry. CD4 and CD8 expressions were also systematically assessed in the same manner.

Results:

Patients with higher TNM stage or high nuclear grade were found to have higher densities of CD45RO. Furthermore, CD45RO status was positively correlated with preoperative C-reactive protein level. In prognostic analysis, CD45RO+lo patients had a significantly better prognosis than CD45RO+hi patients. There was also a significant difference between CD4+lo and CD4+hi groups, whereas no significant difference was observed in CD8 T-cell status. Finally, multivariate analysis revealed that CD45RO+ status was the independent prognostic factor for patient overall survival.

Conclusion:

CD45RO+ memory T-cell status has a significant independent prognostic value, indicating that the adaptive immune response is functionally critical in human RCC.

A randomized trial of personalized peptide vaccine (PPV) plus low-dose estramustine (EMP) versus full-dose EMP in patients with hormone-refractory prostate cancer

3007

Background: Personalized selection of the right peptides for each patient could be a novel peptide-based immunotherapy for boosting anti-cancer immunity in many patients (pts). This randomized study evaluated the anti-tumor effect and safety of PPV plus a low-dose EMP compared with full dose EMP for patients with hormone-refractory prostate cancer (HRPC). Methods: This was a randomized (1:1), open labeled, cross-over study in pts with HRPC. Pts were randomized to arm A; PPV plus low-dose EMP (280 mg/day) or arm B; full dose EMP (560 mg/day) according to age and PSA levels. In arm A, prevaccination plasma were measured for their IgG levels for each of the 14 or 12 candidate peptides which can induce HLA-A2 or A24-restricted CTL activity against cancer cells followed by biweekly subcutaneous administration of the top four peptides (3mg each) showing the strongest IgG responses. Disease progression (PD) was defined as three consecutive and 125% increase from baseline PSA levels at least two weeks apart or objective PD by RECIST criteria. After PD, pts were treated with the opposite regime. The primary endpoint was progression-free survival (PFS), and the secondary endpoints were overall survival and toxicity. The planned sample size was 80. Results: A total of 54 pts from 4 institutions were enrolled between June 2006 and December 2008. The accural into arms A and B was 27 and 27 pts, respectively. The main pts characteristics are (arm A/B): median age 71/69 years, EOCG performance status 0/1 96%/4% and 100%/0%, HLA A2/A24/A2A24 40%/32%/28% and 54%/27%/19%, median PSA 27/25 ng/ml, and metastatic HRPC 96%/85%. All pts were evaluable for their response at the time of interim analysis. The personalized peptide vaccination was well tolerated with no major adverse effects. Increased levels of IgG responses to the vaccinated peptides were observed in 20 of 23 (87%) patients tested. The median PFS time was 246 days in the arm A group and 85 days in the arm B, respectively. The PFS time in the arm A was statistically longer than that in the arm B (log-rank test: p = 0.0007, hazard ratio: 0.27, 95%CI: 0.12 to 0.615). Conclusions: PPV plus low-dose EMP was associated with improvement in PSA-based PFS compared to full-dose EMP alone.

No significant financial relationships to disclose.

Age-stratified serum levels of isoflavones and proportion of equol producers in Japanese and Korean healthy men

Racial differences in the incidence of prostate cancer are manifest worldwide, possibly due to the different dietary habits. To elucidate the relationship between the recent trend of phytoestrogenic isoflavone intake and the increased incidence of prostate cancer in Japan, we conducted an age-stratified dietary survey of soybean foods in 102 Japanese healthy men (age range: 10-59 years) and measured the serum isoflavones and equol levels in them and 100 Korean healthy men. The intergroup comparison among the age-stratified groups showed significant differences in the daily intake of genistein and daidzein between the teenager group and the other groups of age >or=30 years (P<0.05). In the Japanese study, the proportion of equol producers in the teenager group was 10%, being significantly the lowest among the age-stratified groups. The proportions of equol producers in the age-stratified groups from 10 to 49 years were also significantly lower than those in the fifties. The equol non-producers consumed significantly less amounts of isoflavones than the equol producers. In the Korean study, the proportions of equol producers were 45% in the teenager and 40% in the twenties and thirties, being significantly lower than in the forties (80%) and fifties (65%). The decreased intake of isoflavones, low serum level of equol and low incidence of equol production in the young generation may become potential risk factors for prostate cancer not only in Japan but also in Korea in the near future. Elucidating the mechanism of equol production may be promising in developing strategies for chemoprevention against prostate cancer.

Endocrine response to a single injection of goserelin 3.6 mg or leuprolide 3.75 mg in men with prostate cancer

Hormonal responses were assessed in men with prostate cancer (T2-4, Nx, Mx) who were randomized to receive either a single injection of goserelin 3.6 mg or leuprolide 3.75 mg. Testosterone increased over the first week, with a significantly higher mean rate of change of total testosterone (day 3) and free testosterone (days 3 and 7) with leuprolide. Following the initial rise in luteinizing hormone (LH), the rate of decrease in LH levels was significantly greater with goserelin by day 28. There are significant differences in endocrine response to goserelin and leuprolide in the 4 weeks following administration.

Prostatic volume and volume-adjusted prostate-specific antigen as predictive parameters for prostate cancer patients with intermediate PSA levels

The object of the study was to examine the usefulness of volume-adjusted prostate-specific antigen (PSA) parameters for prediction of prostate cancer in the patients with intermediate PSA levels. The subjects were 235 patients with intermediate PSA levels (range: 4.1-10.0 ng/ml) whose prostate volume (PV) and prostate transition zone volume (TZV) were evaluated between August 1996 and April 2004. PSA, PV, TZV, PSA density (PSAD) (PSA/PV) and PSA transition zone density (PSATZD) (PSA/TZV) were assessed with the receiver operating characteristic (ROC) curve and the area under the curve (AUC). Simple and multivariate logistic regression analyses were used to analyze the odds ratios of age, PSA, PSAD, PSATZD, PV, TZV, digital rectal examination (DRE) and transrectal ultrasonography (TRUS) findings. Fifty-five patients (23.4%) of 235 patients had biopsy-proven prostate cancer. The univariate analysis revealed significant differences in the mean values of age, PSAD, PSATZD, PV, TZV and DRE between the patients with cancer and the non-cancer patients. The ROC curve analysis revealed that PV, TZV, PSAD and PSATZD had significant predictive values as compared with that of PSA. However, there was no difference in AUC between them. The stepwise logistic regression analysis showed that the age, PV, PSATZD and DRE had significant predictive values, and that PSATZD had the most predictive power. In conclusion, both PSAD and PSATZD had significant predictive values in discriminating prostate cancer. Furthermore, the stepwise logistic regression analysis showed that PSATZD had the strongest predictive value.