P824The clinical impact of polyunsaturated fatty acid on clinical outcomes in acute coronary syndrome with dyslipidemia: HIJ-PROPER sub-analysis

Background

Polyunsaturated fatty acids, especially omega-3 and -6 series, are key essential nutrients that play an important role in humans to maintain cell membranes and function. A recent randomized trial reported that adding eicosapentaenoic acid (EPA) to statins was beneficial to cardiovascular disease patients who had a residual risk factor. Further, several studies have reported that the low baseline value for EPA to arachidonic acid (AA) ratio is related to worse clinical outcome and plaque vulnerability in coronary artery disease patients. However, effects of baseline EPA/AA ratio on clinical outcomes in ACS patients have not been thoroughly evaluated.

Objectives

This study aimed to examine the impact of baseline eicosapentaenoic acid to arachidonic acid (EPA/AA) ratio on clinical outcomes of acute coronary syndrome (ACS) patients and how lipid-lowering therapy affects serum EPA/AA levels in these patients.

Methods

This is a sub-analysis of HIJ-PROPER assessing the effect of aggressive low-density lipoprotein cholesterol (LDL-C)-lowering treatment with pitavastatin+ezetimibe in 1,734 ACS patients with dyslipidemia. Patients were divided into two groups based on EPA/AA level on admission (cut-off: 0.34 μg/mL; median of baseline EPA/AA level) and clinical outcomes were examined.

Results

Percent reduction of LDL-C from baseline to follow-up and mean LDL-C level during follow-up were similar regardless of baseline EPA/AA ratio. In the low EPA/AA group, the Kaplan–Meier estimate for the primary endpoint at 3 years was 27.2% in the pitavastatin+ezetimibe group, compared with 36.6% in the pitavastatin-monotherapy group [hazard ratio (HR), 0.69; 95% confidence interval (CI), 0.52–0.93; P=0.015). However, in the high EPA/AA group, there was no significant reduction in the primary endpoint by pitavastatin+ezetimibe therapy (HR, 0.92; 95% CI, 0.70–1.20; P=0.52).

Conclusions

Aggressive lipid-lowering therapy with ezetimibe had a positive effect on clinical outcomes in the low EPA/AA group of ACS patients with dyslipidemia, but not in the high EPA/AA group. This effect was independent of LDL-C reduction and suggests that EPA/AA measurement on admission in ACS patients contributes to a “personalized” lipid-lowering approach.

P830Differences in the usefulness of aggressive lipid-lowering therapy among single-vessel and multi-vessel coronary artery disease patients: HIJ-PROPER sub-study

Background

Acute coronary syndrome (ACS) patients with multi-vessel disease (MVD) are at high risk of recurrent cardiovascular events. Previous study, examining stable atherosclerotic cardiac disease, reported that aggressive lipid-lowering therapy was more beneficial in MVD patients than in single-vessel disease (SVD) patients. However, no report has investigated the effects of aggressive lipid-lowering treatment according to the number of diseased coronary arteries in ACS patients.

Purpose

The purpose of the present study was to elucidate the efficacy of aggressive lipid-lowering therapy in ACS patients with MVD and SVD in modern early invasive strategy era.

Methods

The study population was derived from the HIJ-PROPER study, in which, ACS patients with dyslipidemia were randomized to pitavastatin + ezetimibe therapy (targeting LDL-C less than 70mg/dl) or pitavastatin-monotherapy (targeting LDL-C less than 90mg/dl). In the present study, the treatment efficacy was compared between patients with MVD and SVD. The primary end point was a composite of major advanced cardiovascular events (MACEs), including all-cause death, non-fatal myocardial infarction, non-fatal stroke, and ischemia driven revascularization.

Results

We identified 1702 eligible patients (mean age, 65.6 years; male, 75.6%); 869 patients (51.1%) had MVD and 833 (48.9%) patients had SVD. The rate of acute revascularization was 96.2%. The incidence of MACEs was significantly higher in MVD group compared to SVD group (43.7% vs 25.9%, hazard ratio 1.95, 95% confidence interval 1.65–2.31, p<0.001). In MVD group, there was no significant difference in MACEs between pitavastatin + ezetimibe therapy and pitavastatin-monotherapy group. (43.5% vs. 43.9%, 1.0, 0.82–1.23; p=0.95). However, in SVD group, pitavastatin + ezetimibe therapy showed significantly fewer MACEs than pitavastatin-monotherapy (34.6% vs. 47.4%, 0.72, 0.55–0.94, p=0.02). (Figure)

Conclusion

This study showed that ACS patients with SVD enjoyed significantly greater benefits from pitavastatin + ezetimibe therapy compared with pitavastatin monotherapy, whereas the patients with MVD did not. High rate of revascularization in acute phase of ACS might affect the efficacy of aggressive lipid-lowering therapy and our results in the present study suggest different treatment approach would be necessary in ACS patients with MVD in modern early invasive strategy era.

P6339Sequential organ failure assessment score on admission predicts long-time mortality of the patients with acute heart failure

Background

Despite the remarkable advances in the treatment options of acute heart failure (HF), prognosis assessment remains an ongoing challenge. Previous studies revealed only a moderate accuracy of models predicting mortality. Sequential Organ Failure Assessment (SOFA) Score are widely used in the intensive care unit (ICU) to predict outcome and predicted higher long-time mortality in unselected patients in cardiac ICU. In addition, the American Heart Association Get With the Guidelines–Heart Failure (GWTG-HF) risk score allows for risk stratification of 30-day outcome for patients hospitalized with HF. The purpose of this study was to evaluate whether SOFA score on admission is useful for long-time mortality prediction in acute HF patients and also to assess the discriminative performance as compared with GWTG-HF risk score.

Methods

This was a single-centre, retrospective cohort study. Between January 2007 and December 2016, we screened eligible 661 consecutive patients with acute HF administered at our hospital. SOFA score on admission of 294 patients was able to calculate retrospectively. We enrolled 269 patients who could complete follow up evaluation for more than 1 year. Endpoint was all-cause mortality after admission. Additive information of SOFA score was evaluated by area under the curve (AUC), net reclassification improvement (NRI), integrated discrimination improvement (IDI) and decision curve analysis (DCA).

Results

The 269 patients were included in this study (78.5±10.9 years; 136 men; left ventricular ejection fraction [EF], 49.8±16.6%) during a mean follow-up of 32.1±22.3 months. Patients with all-cause death had higher SOFA score (4.2±2.3 versus 2.8±1.8, p<0.001; AUC, 0.689) and GWTG-HF risk score (44.0±7.6 versus 38.1±7.9, P<0.001, AUC, 0.692).

Kaplan-Meier survival analysis demonstrated higher SOFA scores (P<0.001) and GWTG-HF risk scores (P<0.001) appears to be related to increase probabilities of all cause death. A multivariate Cox proportional hazard model were made with adjustment for SOFA score, GWTG-HF risk score, age, gender and ejection fraction. As a result, SOFA score (hazard ratio [HR] 1.227; 95% confidence interval [CI], 1.130 to 1.326; P<0.001), GWTG-HF (HR, 1.054; 95% CI, 1.029 to 1.078; P<0.001) and age (HR, 1.069; 95% CI 1.048 to 1.092; P<0.001) were independent predictors of all cause death and HR of SOFA score was the highest in these parameters. Incorporating SOFA score into GWTG-HF score yielded a significant NRI (0.528 (95% CI 0.291 to 0.765) and IDI (0.046 (95% CI 0.020 to 0.072). In DCA, compared with the reference model, the net benefit for SOFA score model was greater across the range of threshold probabilities.

Conclusions

The SOFA score, simple and validated mortality risk score can predict long-term all-cause mortality in patients with acute HF. Discriminative performance metrics such as NRI, IDI and DCA were improved on incorporation of the SOFA score for prediction of mortality.

P5577Preoperative transaortic pressure gradient predicts renal functional improvement after transcatheter aortic valve implantation in patients with chronic kidney disease

Introduction

Transcatheter aortic valve implantation (TAVI) theoretically increases renal blood flow through increasing cardiac output by relieving aortic valvular obstruction of blood flow from left ventricle, resulting in a renal functional recovery in patients with severe aortic valve stenosis (AS). However, procedural steps of TAVI including contrast use potentially damages renal medulla and may deteriorate renal function.

Purpose

The aim of this study was to investigate renal functional change and clarify preoperative predictors for renal functional improvement after TAVI in chronic kidney disease (CKD) patients with severe AS.

Methods

A total of 88 consecutive severe AS patients with CKD (grade >3) who underwent TAVI from 2015 to 2018 was enrolled in this observational study. They were divided into two groups depending on their renal functional improvement after TAVI that was defined as more than 10% increase in estimated glomerular filtration rate (eGFR) at discharge from their preoperative level.

Results

Among the whole candidates, 49 patients (55.7%) were improved their renal function. Patients with the lowest preoperative eGFR achieved the highest increase in eGFR after TAVI (CKD grade >4: +22.7±23.7%, Figure). Patients in the Improved group had lower hemoglobin level, higher mean transaortic pressure gradient (TAPG), and higher aortic valve gradient before TAVI, compared to those in the Non-improved group. However, contrast volume during the procedure was not significantly different between the groups. Multivariate logistic regression analysis revealed that high mean TAPG and low left ventricular ejection fraction (LVEF) before TAVI were independent predictors for the improvement of renal function (odds ratio (OR): 1.04, 95% confidence interval (CI): 1.00–1.08; OR: 0.94, 95% CI: 0.89–0.99, respectively), even after the adjustment of baseline eGFR level and hemoglobin level that were statistically significant on univariate logistic regression analysis. Receiver Operating Characteristic (ROC) curve showed the cut-off level of preoperative mean TAPG in renal functional improvement after TAVI as 47.0 mmHg (Sensitivity: 47.9%, Specificity: 79.5%, area under the curve: 0.62).

Correlation between CKDgrade and ΔeGFR

Conclusions

Preoperative high mean TAPG may predict renal functional improvement after TAVI in patients with deteriorated renal function. This non-invasive predictor may help clinicians to consider to perform TAVI in a challenging case with severe CKD.

Identification of Arabidopsis CCR4-NOT Complexes with Pumilio RNA-Binding Proteins, APUM5 and APUM2

CCR4/CAF1 are widely conserved deadenylases in eukaryotes. They form a large complex that includes NOT1 as a scaffold protein and various NOT proteins that are core components of multiple levels of gene expression control. The CCR4-NOT complex also contains several RNA-binding proteins as accessory proteins, which are required for target recognition by CCR4/CAF1 deadenylases. AtCCR4a/b, orthologs of human CCR4 in Arabidopsis, have various physiological effects. AtCCR4 isoforms are likely to have specific target mRNAs related to each physiological effect; however, AtCCR4 does not have RNA-binding capability. Therefore, identifying factors that interact with AtCCR4a/b is indispensable to understand its function as a regulator of gene expression, as well as the target mRNA recognition mechanism. Here, we identified putative components of the AtCCR4-NOT complex using co-immunoprecipitation in combination with mass spectrometry using FLAG-tagged AtCCR4b and subsequent verification with a yeast two-hybrid assay. Interestingly, four of 11 AtCAF1 isoforms interacted with both AtCCR4b and AtNOT1, whereas two isoforms interacted only with AtNOT1 in yeast two-hybrid assays. These results imply that Arabidopsis has multiple CCR4-NOT complexes with various combinations of deadenylases. We also revealed that the RNA-binding protein Arabidopsis Pumilio 5 and 2 interacted with AtCCR4a/b in the cytoplasm with a few foci.

Benign hilar bile duct strictures resected as perihilar cholangiocarcinoma

BACKGROUND

Differentiation between perihilar cholangiocarcinoma (PHCC) and benign strictures is frequently difficult. The aim of this study was to investigate the incidence and long-term outcome of patients with tumours resected because of suspicion of PHCC, which ultimately turned out to be benign (malignancy masquerade).

METHODS

Patients who underwent surgical resection with a diagnosis of PHCC between 2001 and 2016 were reviewed retrospectively.

RESULTS

Among 707 consecutive patients, 685 had PHCC and the remaining 22 (3·1 per cent) had benign biliary stricture. All patients with benign disease underwent major hepatectomy, with no deaths. Preoperative histological assessment using bile duct biopsy or aspiration cytology had a high specificity (90 per cent), low sensitivity (62 per cent) and unsatisfactory accuracy (63 per cent). Despite the increasing use of histological assessment, the incidence of benign strictures resected did not decrease over time, being 0·9 per cent in 2001-2004, 4·0 per cent in 2005-2008, 3·8 per cent in 2009-2012 and 2·9 per cent in 2013-2016. The final pathology of benign strictures included IgG4-related sclerosing cholangitis (9 patients), hepatolithiasis (4), granulomatous cholangitis (3), non-specific chronic cholangitis (3), benign strictures after cholecystectomy (2), and a benign stricture possibly caused by parasitic infection (1). The 10-year overall survival rate for the 22 patients with benign stricture was 87 per cent, without recurrence of biliary stricture.

CONCLUSION

The incidence of benign strictures resected as PHCC as a proportion of all resections was relatively low, at 3·1 per cent. Currently, unnecessary surgery for suspected PHCC is unavoidable.

Modulation of extrasynaptic GABAA alpha 5 receptors in the ventral hippocampus normalizes physiological and behavioral deficits in a circuit specific manner

Hippocampal hyperactivity is correlated with psychosis in schizophrenia patients and likely attributable to deficits in GABAergic signaling. Here we attempt to reverse this deficit by overexpression of the α5-GABAA receptor within the ventral hippocampus (vHipp). Indeed, this is sufficient to normalize vHipp activity and downstream alterations in dopamine neuron function in the MAM rodent model. This approach also attenuated behavioral deficits in cognitive flexibility. To understand the specific pathways that mediate these effects, we used chemogenetics to manipulate discrete projections from the vHipp to the nucleus accumbens (NAc) or prefrontal cortex (mPFC). We found that inhibition of the vHipp-NAc, but not the vHipp-mPFC pathway, normalized aberrant dopamine neuron activity. Conversely, inhibition of the vHipp-mPFC improved cognitive function. Taken together, these results demonstrate that restoring GABAergic signaling in the vHipp improves schizophrenia-like deficits and that distinct behavioral alterations are mediated by discrete projections from the vHipp to the NAc and mPFC.

Atrial fibrillation type matters: greater infarct volume and worse neurological defects seen in acute cardiogenic cerebral embolism due to persistent or permanent rather than paroxysmal atrial fibrillation

Aims

Some studies have shown that the type of atrial fibrillation (AF), whether paroxysmal AF (PAF) or persistent or permanent AF (PeAF), affects the incidence of ischaemic stroke. This study sought to determine the relationship between the AF pattern and the severity and brain volume of infarction in an AF population including transient ischaemic attack (TIA) patients.

Methods and results

This was a retrospective observational study. We studied 161 consecutive patients who were admitted to our stroke care unit with cardiogenic embolism or TIA related to non-valvular AF (age 79 ± 9.5, 78 females, and 87 PAF patients). We evaluated the differences in severity and infarct volume between the types of AF. Additionally, we divided the patients into three groups according to severe stroke (n = 38), TIA (n = 28), and those who were neither (stroke, n = 95) for the assessment of the predictors of severe stroke and TIA. Persistent or permanent atrial fibrillation patients with acute cardiogenic stroke or TIA had worse peak National Institute of Health Stroke Scale (NIHSS) scores [PAF median 4 (range 3-14), PeAF 17 (5.8-25); P < 0.0001] and worse NIHSS scores at discharge [PAF 2.0 (1-7), PeAF 11 (3-22); P < 0.0001]. Their infarct brain volume assessed by computed tomography or magnetic resonance imaging was also larger [PAF 4.4 (1.1-32) mL, PeAF 64 (6.9-170) mL; P < 0.0001]. Multivariate analysis of severe stroke vs. non-severe stroke patients showed that having PeAF was the only independent predictor of severe stroke [odds ratio (OR) 4.27, 95% confidence interval (CI) 1.91-10.2; P = 0.0003]. Comparison of TIA vs. non-TIA patients showed that PeAF (OR 0.120, 95% CI 0.0230-0.444; P = 0.0008) and anticoagulant use (OR 8.24, 95% CI 2.15-40.8; P = 0.0018) were independent predictors of TIA.

Conclusion

Cardiogenic emboli due to non-valvular PeAF are associated with a worse acute clinical course and greater volume of infarction than those due to PAF.

New implications for the recurrence mechanism of an upper septal ventricular tachycardia: a case report

Background

Verapamil-sensitive fascicular ventricular tachycardia (VT) is the most common type of idiopathic left ventricular tachycardia, and it is divided into three types. Upper septal ventricular tachycardia (US-VT) is likely in patients with prior episodes of left posterior fascicular (LPF)-VT ablation, however, little is known about the recurrence mechanism of US-VT.

Case summary

A 53-year-old man had an US-VT after two catheter ablation sessions for a common idiopathic LPF-VT. The US-VT was successfully treated by ablating the proximal site of the LPF without making any further branch or fascicular block. This successful ablation point corresponded completely with the earliest pre-systolic potential (P2) site of the LPF-VT during the 1st session of catheter ablation.

Discussion

An US-VT recurrence could occur if a critical slow conduction is not affected by the catheter ablation. This recurrence might be the result of changing the re-entrant circuit after damage to the LPF. In order to eliminate the LPF-VT and prevent an US-VT recurrence, the earliest P2 site should be investigated carefully and ablated sufficiently.

Prepatterning of Papilio xuthus caterpillar camouflage is controlled by three homeobox genes: clawless, abdominal-A, and Abdominal-B

Color patterns often function as camouflage to protect insects from predators. In most swallowtail butterflies, younger larvae mimic bird droppings but change their pattern to mimic their host plants during their final molt. This pattern change is determined during the early fourth instar by juvenile hormone (JH-sensitive period), but it remains unclear how the prepatterning process is controlled. Using Papilio xuthus larvae, we performed transcriptome comparisons to identify three camouflage pattern-associated homeobox genes [clawless, abdominal-A, and Abdominal-B (Abd-B)] that are up-regulated during the JH-sensitive period in a region-specific manner. Electroporation-mediated knockdown of each gene at the third instar caused loss or change of original fifth instar patterns, but not the fourth instar mimetic pattern, and knockdown of Abd-B after the JH-sensitive period had no effect on fifth instar patterns. These results indicate the role of these genes during the JH-sensitive period and in the control of the prepatterning gene network.

Relationships between blood pressure lowering therapy and cardiovascular events in hypertensive patients with coronary artery disease and type 2 diabetes mellitus: The HIJ-CREATE sub-study

OBJECTIVE

The effects of intensive blood pressure (BP) lowering for hypertensive patients with coronary artery disease (CAD) and diabetes mellitus on their clinical outcomes have not been fully evaluated. The aim was to explore the optimal systolic BP target in such patients in a substudy of a prospective, randomized trial.

METHODS

Of a total of 2049 hypertensive patients with CAD who were enrolled in the HIJ-CREATE study, type 2 diabetes was diagnosed in 780 (38.1%). Titration of antihypertensive agents was performed to reach the target BP of <130/85 mmHg. The primary endpoint was the occurrence of a first major adverse cardiovascular event (MACE). Achieved BP was defined as the mean value of systolic BP in patients who did not develop MACEs and as the mean value of systolic BP prior to MACEs in those who developed MACEs during follow-up.

RESULTS

During a median follow-up of 4.2 years, the primary outcome occurred in 259 (33.2%) diabetic patients and in 293 (23.1%) non-diabetic patients (p < 0.0001). The diabetic patients were divided into quartiles based on the mean systolic BP during follow-up. The relationships between achieved BP and the incidence of MACEs did not follow a J-shaped curve. Intensive systolic BP lowering to less than 120 mmHg did not correlate with an increased risk of MACEs.

CONCLUSIONS

Our results suggest that the intensive BP lowering may not impair patients' clinical courses even in a high-risk population. The establishment of an optimal management strategy for hypertensive patients with diabetes and CAD is essential.

Major hepatectomy with or without pancreatoduodenectomy for advanced gallbladder cancer

BACKGROUND

The indications for major hepatectomy for gallbladder cancer either with or without pancreatoduodenectomy remain controversial. The clinical value of these extended procedures was evaluated in this study.

METHODS

Patients who underwent major hepatectomy for gallbladder cancer between 1996 and 2016 were identified from a prospectively compiled database. Postoperative outcomes and overall survival were compared between patients undergoing major hepatectomy alone or combined with pancreatoduodenectomy (HPD).

RESULTS

Seventy-nine patients underwent major hepatectomy alone and 38 patients had HPD. The patients who underwent HPD were more likely to have T4 disease (P < 0·001), nodal metastasis (P = 0·015) and periaortic nodal metastasis (P = 0·006), but were less likely to receive adjuvant therapy (P = 0·006). HPD was associated with a high incidence of grade III or higher complications (P = 0·002) and death (P = 0·037). Overall survival was longer in patients who underwent major hepatectomy alone than in patients who underwent HPD (median survival time 32 versus 10 months; P < 0·001). In multivariable analysis, surgery in the early period (1996-2006) (P = 0·002), pathological T4 disease (P = 0·005) and distant metastasis (P < 0·001) were associated with shorter overall survival, and cystic duct tumour (P = 0·002) with longer overall survival.

CONCLUSION

Major hepatectomy alone for gallbladder cancer contributes to favourable overall survival with low morbidity and mortality, whereas HPD is associated with poor overall survival and high morbidity and mortality rates. HPD may eradicate locally spreading gallbladder cancer; however, the indication for the procedure is questioned from an oncological viewpoint.

Involvement of the membrane-localized ubiquitin ligase ATL8 in sugar starvation response in Arabidopsis

As major components of the ubiquitin system, ubiquitin ligases mediate the transfer of ubiquitin to specific target substrates, thereby playing important roles in regulating a wide range of cellular processes. The Arabidopsis Tóxicos en Levadura (ATL) family is a group of plant-specific RING-type ubiquitin ligases with N-terminal transmembrane-like domains. To date, 91 ATL isoforms have been identified in the Arabidopsis genome, with some reported to regulate plant responses to environmental stresses. However, the functions of most ATLs remain unclear. This study showed that ATL8 is a sugar starvation response gene and that ATL8 expression was significantly increased by sugar starvation conditions but repressed by exogenous sugar supply. The ATL8 protein was found to possess ubiquitin ligase activity in vitro and to localize to membrane-bound compartments in plant cells. In addition, Starch Synthase 4 was identified as a putative interactor with ATL8, suggesting that ATL8 may be involved in modulating starch accumulation in response to sugar availability. These findings suggest that ATL8 functions as a membrane-localized ubiquitin ligase likely to be involved in the adaptation of Arabidopsis plants to sugar starvation stress.

Comparison of direct oral anticoagulants and warfarin regarding midterm adverse events in patients with atrial fibrillation undergoing catheter ablation

BACKGROUND

Oral anticoagulants, including direct oral anticoagulants (DOACs), are usually required in atrial fibrillation (AF) patients who are at a high risk of thromboembolism (TE), even if they had undergone catheter ablation (CA). Although several studies have reported the safety and efficacy of DOACs around CA in AF patients, there are only limited data regarding the midterm incidence of TE and bleeding complications post-CA among AF patients treated with warfarin or DOACs.

METHODS

We studied 629 AF patients (mean age: 65.3 ± 10.3 years; 442 men) undergoing CA, to calculate the midterm incidence of TE and bleeding complications associated with warfarin or DOACs.

RESULTS

In total, 292 patients used warfarin and 337 used DOACs (dabigatran: 90 patients; rivaroxaban: 137; and apixaban: 110). At baseline, the CHA2DS2-VASc and HAS-BLED scores were similar between the 2 groups. During a median follow-up period of 7 months, no TE complications occurred. The warfarin group had a significantly higher bleeding event rate than did the DOACs group (all bleeding complications: 32 [11.0%] vs 15 [4.5%], respectively, P = .002). The rate of all bleeding complications was significantly higher in the warfarin group than in the DOACs group (10.1% vs 3.7%, respectively, at 10 months; P = .024). In Cox proportional hazards modeling, DOAC use was significantly associated with a decreased risk of bleeding (adjusted hazard ratio: 0.497; 95% confidence interval: 0.261-0.906, P = .022).

CONCLUSIONS

Direct oral anticoagulant use in AF patients undergoing CA may be associated with a similar risk of TE as warfarin but is associated with a lower risk of bleeding.

Sugar-responsive transcription factor bZIP3 affects leaf shape in Arabidopsis plants

Sugars are essential for plant metabolism, growth and development. Plants must therefore manage their growth and developmental processes in response to sugar availability. Sugar signaling pathways constitute a complicated molecular network and are associated with global transcriptional regulation. However, the molecular mechanisms underlying sugar signaling remain largely unclear. This study reports that the protein basic-region leucine zipper 3 (bZIP3) is a novel sugar-responsive transcription factor in Arabidopsis plants. The expression of bZIP3 was rapidly repressed by sugar. Genetic analysis indicated that bZIP3 expression was modulated by the SNF1-RELATED KINASE 1 (SnRK1) pathway. Moreover, transgenic plants overexpressing bZIP3 and dominant repressor form bZIP3-SRDX showed aberrant shaped cotyledons with hyponastic bending. These findings suggest that bZIP3 plays a role in plant responses to sugars and is also associated with leaf development.

Impact of impedance decrease during radiofrequency current application for atrial fibrillation ablation on myocardial lesion and gap formation

BACKGROUND

The clinical impact of a decrease in impedance during radiofrequency catheter ablation (RFCA) has not been fully clarified. The aim of the study was to analyze the impact of impedance decrease and to determine its optimal cutoff value during RFCA.

METHODS

We evaluated 34 consecutive patients (total 3264 lesions, mean age 66 ± 8.7 years, 10 females) who underwent their first ablation for atrial fibrillation (AF). The impedance decrease, average contact force (CF), application time, force-time integral (FTI), product of impedance decrease and application time (PIT), and the product of impedance decrease and FTI (PIFT) were measured for all lesions. Levels of cardiac troponin I (TrpI) were measured for assessment of myocardial injury. The incidence of intraprocedural pulmonary vein-left atrium reconnection or dormant conduction (reconnection) was determined. The relationships between the ablation parameters and the increase in TrpI (ΔTrpI) were evaluated. The predictive value of the parameters for reconnection was assessed using receiver operating characteristic (ROC) curve analysis.

RESULTS

Reconnection was detected in 18 patients. Average FTI and PIT were significantly correlated with ΔTrpI (FTI: r2 = .19, P = .0090, PIT: r2 = .21, P = .0058). PIFT was correlated with ΔTrpI and was the best of the three indexes (PIFT: r2 = .29, P = .0010). In ROC curve analysis, the area under the curve for predicting reconnection was 0.71 and the optimal cutoff value was 5200 for PIFT (sensitivity 78%, specificity 63%).

CONCLUSION

The combination of CF and a decrease in impedance could be important in the evaluation of myocardial lesions and reconnection during RFCA.