Predictors and incidence of health status deterioration in patients with early atrial fibrillation

BACKGROUND

Various treatment approaches for atrial fibrillation (AF) have demonstrated improved health status, yet the significance of these therapeutic interventions in individual patients remains unclear.

OBJECTIVE

This study aimed to evaluate health status changes in patients with early AF, focusing on those who experience clinically significant deterioration after treatment initiation.

METHODS

We analyzed data from a multicenter, prospective registry of newly diagnosed patients with AF. One-year changes in health status across different treatment strategies were assessed by the Atrial Fibrillation Effect on QualiTy-of-life Overall Summary (AFEQT-OS) score. Clinically relevant deterioration and improvement in health status were defined as ≥5-point decrease and increase in AFEQT-OS score, respectively; no change was -5 to 5 points.

RESULTS

Overall, 1960 patients with AF were evaluated. Mean AFEQT-OS scores at baseline and 1-year follow-up were 76.7 ± 17.7 and 85.4 ± 14.8, respectively. Although most patients (53.9%) experienced clinically important improvement, a considerable proportion had no change (28.7%) or deterioration (17.4%) in their health status. Proportions of patients with no change or deterioration varied by treatment strategy: 59.9%, 53.9%, and 32.0% in rate control, antiarrhythmic drug, and catheter ablation groups, respectively. The multivariable model identified older age, female sex, heart failure, coronary artery disease, and higher baseline AFEQT-OS score as independent predictors of worsening health status, regardless of treatment strategy.

CONCLUSION

Many patients with early AF experience worsening or no change in health status irrespective of treatment strategy. Standardizing patients' health status assessment, especially for patients with comorbidities, may aid in patients' selection and their outcomes.

Prognostic Implications and Efficacy of Catheter Ablation by Atrial Fibrillation Type

Background Catheter ablation (CA) for atrial fibrillation (AF) is preferred for paroxysmal AF (PAF) but selectively performed in patients with persistent AF (PersAF). This study aimed to investigate the prognostic differences and consequences of CA based on the AF type. Methods and Results Data from a multicenter AF cohort study were analyzed, categorizing patients as PAF or PersAF according to AF duration (≤7 or >7 days, respectively). A composite of all-cause death, heart failure hospitalization, stroke, and bleeding events during 2-year follow-up and changes in the Atrial Fibrillation Effect on Quality-of-life score were compared. Additionally, propensity score matching was performed to compare clinical outcomes of patients with and without CA in both AF types. Among 2788 patients, 51.6% and 48.4% had PAF and PersAF, respectively. Patients with PersAF had a higher incidence of the composite outcome (12.8% versus 7.2%; P<0.001) and smaller improvements in Atrial Fibrillation Effect on Quality-of-life scores than those with PAF. After adjusting for baseline characteristics, PersAF was an independent predictor of adverse outcomes (adjusted hazard ratio, 1.35 [95% CI, 1.30-1.78], P=0.031) and was associated with poor improvements in Atrial Fibrillation Effect on Quality-of-life scores. Propensity score matching analysis showed that the CA group had significantly fewer adverse events than the medication group among patients with PAF (odds ratio, 0.31 [95% CI, 0.18-0.68]; P=0.002). Patients with PersAF showed a similar but nonsignificant trend. Conclusions PersAF is a risk factor for worse clinical outcomes, including patients' health status. CA is associated with fewer adverse events, although careful consideration is required based on the AF type.

Delineation of conduction gaps of linear lesions during atrial fibrillation ablation using ultra-high-density mapping

AIMS

Linear lesions are routinely created by radiofrequency catheter ablation. Unwanted electrical conduction gaps can be produced and are often difficult to ablate. This study aimed to clarify the characteristics of conduction gaps during atrial fibrillation ablation by analysing bidirectional activation maps using a high-density mapping system (RHYTHMIA).

METHODS AND RESULTS

This retrospective study included 31 patients who had conduction gaps along pulmonary vein (PV) isolation or box ablation lesions. Activation maps were sequentially created during pacing from the coronary sinus and PV to reveal the earliest activation site, defined by the entrance and exit. The locations, length between the entrance and exit (gap length), and direction were analysed. Thirty-four bidirectional activation maps were drawn: 21 were box isolation lesions (box group), and 13 were PV isolation lesions (PVI group). Among the box group, nine conduction gaps were present in the roof region and 12 in the bottom region, while nine in right PV and four in left PV among the PVI group. Gap lengths in the roof region were longer than those in the bottom region (26.8 ± 11.8 vs. 14.5 ± 9.8 mm; P = 0.022), while those in right PV tended to longer than those in left PV (28.0 ± 15.3 vs. 16.8 ± 8.0 mm, P = 0.201).

CONCLUSION

The entrances and exits of electrical conduction gaps were separated, especially in the roof region, indicating that epicardial conduction might contribute to gap formation. Identifying the bidirectional conduction gap might indicate the location and direction of epicardial conduction.

Characteristics and health-status outcomes in patients with atrial fibrillation detected via health screening

BACKGROUND

Early detection of atrial fibrillation (AF) is important. Japan has a universal screening system, and regular health screening (HS) is available to support AF detection without a hospital visit. However, health-related outcomes and other characteristics of HS-detected and conventionally diagnosed AF remain unknown.

HYPOTHESIS

That the characteristics and health-related outcomes of patients with HS-detected AF may differ from those of patients whose AF was detected by other procedures.

METHODS

In total, 3318 consecutive newly referred AF cases were enrolled; demographic characteristics and health-related and clinical outcomes were compared between two groups created based on the mode of AF detection (the HS and non-HS groups). Health-related outcomes were assessed using the AF Effect on QualiTy-of-life (AFEQT) questionnaire at baseline and after 1 year of follow-up.

RESULTS

AF was detected by HS in 25.0% of patients; these patients had lower CHADS₂ scores (1.01 vs. 1.50, p < .001), higher prevalence of persistent AF (odds ratio, 95% confidence interval; 2.21, 1.88-2.60) and asymptomatic presentation (3.19, 2.71-3.76), and better baseline QoL scores (83.6 vs. 75.0; p < .001). Catheter ablation was more frequently performed in the HS group at follow-up (44.4% vs. 34.1%; p < .001). At 1-year follow-up, the AFEQT scores of the HS group were significantly better in most subdomains.

CONCLUSIONS

In the Japanese registry, AF was detected via HS in 25% of patients referred to specialty centers for management. Notably, the overall health status of patients with HS-detected AF improved after medical interventions, including catheter ablations.

Advantage of POLARx over ARCTIC FRONT ADVANCE PRO during pulmonary vein isolation for paroxysmal atrial fibrillation

Introduction

The electrical pulmonary vein (PV) isolation has been established as a curative therapy for paroxysmal atrial fibrillation (AF). Arctic Front™cryoballoon has been used worldwide for AF cryoablation. Recently, a new cryoballoon, POLARxTM CRYOABLATION system have been introduced, of which material of the balloon is softer and the N2O gas flow rate is higher.

Purpose

The aim was to investigate the procedural parameter and efficacy of POLARx comparing with Arctic Front.

Methods

This retrospective single center study included 101 consecutive patients who underwent paroxysmal AF ablation using cryoballoon at Keio University hospital from April 2021 to March 2022. The procedural data including the cryoballoon temperature and the number and duration of cryoablation were compared between POLARx (POLARx group) and ARCTIC FRONT ADVANCE PRO (AFA group). After the cryoablation, we added the radiofrequency application in order to maximize the isolated area when the voltage was remained inside PV (Figure 1). The necessities of the additional radiofrequency applications were also compared.

Results

In the present study, 64 patients in AFA group and 37 patients in POLARx group were analyzed. POLARx group included younger population and less females (62.8±9.9 vs 67.5±9.4 year of age, P=0.02; 13.5 vs 32.8%, P=0.04). There was no significant difference in comorbidities and examination data such as left atrium diameter or brain natriuretic peptide level. The minimal cryoballoon temperatures reached in POLARx group were lower than AFA group (−59.3±6.2 vs −47.7±7.5°C, P&lt;0.01). No difference was found in the total number and duration of cryoablation and the time to isolate PV (6.1±2.1 vs 5.9±1.6, P=0.69; 790.2±256.1 vs 776.1±235.0 sec, P=0.69; 41.8±21.3 vs 47.1±29.6 sec, P=0.44, respectively). With regard to individual PVs, the total number and duration were tended to be larger at right superior PV in POLARx group (1.9±1.1 vs 1.4±0.7, P=0.01; 231.8±123.8 vs 193.2±83.0 sec, P=0.07), while there was no significant difference at the other PVs. The rate of successful PV isolation by a single cryo-application was not different between AFA and POLARx group (54.3 vs 61.4%, P=0.17). The additional radiofrequency applications were more frequent in AFA group (14.8 vs. 4.9%, P=0.003). There was a significant difference at right inferior PV (32.8 vs 8.1%, P=0.01), while not at left superior PV, left inferior PV and right superior PV (9.4 vs 2.9%, P=0.42; 9.4 vs 5.7%, P=0.71; 7.8 vs 2.7%, P=0.41). Phrenic nerve injury was occurred 1 case in both group and esophageal ulcer was occurred in 1 case in AFA group. No other complication including cardiac tamponade was occurred.

Conclusion

The total number and duration of cryoablation were not significantly different between AFA and POLARx group, except for right superior PV. There was an advantage in largely isolating right inferior PV in POLARx group comparing with AFA group.

Funding Acknowledgement

Type of funding sources: None.

Change in the local impedance and electrograms recorded by a micro-electrode tip catheter during initial atrial fibrillation ablation

BACKGROUND

A novel measurement of the local impedance (LI) and electrograms recorded from micro-electrodes on catheter tip has been developed. However, the data during pulmonary vein (PV) ablation is not sufficient. We aimed to investigate the utility of this measurement during initial atrial fibrillation (AF) ablation.

METHODS

We investigated 111 representative radiofrequency applications in 7 AF patients without a history of prior ablation (6 males, age 68 [65-72] years, 2 persistent AF). The ablation strategy was PV isolation for paroxysmal AF and single ring box isolation for persistent AF, using MiFi catheter. The correlation of the generator impedance (GI) drop and LI drop after radiofrequency applications and the predictive value of the initial LI elevation before radiofrequency applications for LI drop were analyzed. Also, the LI and GI drop were investigated according to the location of RF applications.

RESULTS

The LI drop was higher than GI drop (23.7 [16.4-35.7] and 9.0 [6.0-12.0]; P < .01). There were correlations between the initial LI elevation and LI drop (R 2 = 0.466, P < .01) and between the LI and GI drop (R 2 = 0.263, P < .01). The LI drops significantly differed according to the different anatomical localizations by the Kruskal-Wallis test, although the GI drops did not differ (P < .01 and P = .49, respectively).

CONCLUSION

LI drop was associated with initial LI elevation and was larger than GI drop. LI drop was different according to locations, although GI drop was not. These findings might indicate that LI drop would be a more sensitive marker for lesion formation than GI drop.

Blood levels of heme oxygenase-1 versus bilirubin in patients with coronary artery disease

OBJECTIVE

Heme oxygenase-1 (HO-1) degrades heme to CO, iron, and biliverdin/bilirubin. Although serum bilirubin levels were often reported in patients with coronary artery disease (CAD), HO-1 levels in patients with CAD and the association between HO-1 and bilirubin levels have not been clarified.

METHODS

We measured plasma HO-1 and serum total bilirubin levels in 262 patients undergoing coronary angiography.

RESULTS

HO-1 levels were higher in patients with CAD than without CAD (median 0.46 vs. 0.35 ng/mL, P < 0.01), but bilirubin were lower in patients with CAD than without CAD (0.69 vs. 0.75 mg/dL, P < 0.02). Notably, HO-1 levels in CAD(-), 1-vessel, 2-vessel, and 3-vessel disease were 0.35, 0.51, 0.45, and 0.44 ng/mL, and were highest in 1-vessel disease (P < 0.05). Bilirubin levels in CAD(-), 1-vessel, 2-vessel, and 3-vessel disease were 0.75, 0.70, 0.68, and 0.66 mg/dL (P = NS). No correlation was found between HO-1 and bilirubin levels. In multivariate analysis, HO-1 levels were a significant factor for CAD independent of atherosclerotic risk factors and bilirulin levels. Odds ratio for CAD was 2.32 (95%CI = 1.29-4.17) for high HO-1 (>0.35 ng/mL).

CONCLUSIONS

Patients with CAD were found to have high HO-1 and low bilirubin levels in blood, but no correlation was found between HO-1 and bilirubin levels.

Associations Between Plasma Betatrophin Levels and Coronary and Peripheral Artery Disease

Aim: Betatrophin, a recently identified circulating adipokine, affects lipid and glucose metabolism. However, association between plasma betatrophin levels and atherosclerotic diseases, such as coronary artery disease (CAD) and peripheral artery disease (PAD), has not been elucidated.

Methods: We investigated plasma betatrophin levels in 457 patients undergoing elective coronary angiography who also had ankle-brachial index (ABI) test for PAD screening.

Results: Of the 457 study patients, CAD was present in 241 patients (53%) (1-vessel [1-VD], n = 99; 2-vessel [2-VD], n = 71; 3-vessel disease [3-VD], n = 71). Compared to 216 patients without CAD, 241 with CAD had higher betatrophin levels (median 1120 vs. 909 pg/mL, p < 0.001). A stepwise increase in betatrophin levels was found depending on the number of > 50% stenotic coronary vessels: 909 in CAD(-), 962 in 1-VD, 1097 in 2-VD, and 1393 pg/ml in 3-VD (p < 0.001). Betatrophin levels correlated with the number of > 25% stenotic segments (r = 0.24, p < 0.001). PAD (ABI < 0.9) was found in 41 patients (9%). Plasma betatrophin levels were also significantly higher in 41 patients with PAD than in 416 without PAD (1354 vs. 981 pg/mL, p < 0.001). In the multivariate analysis, betatrophin levels were not a factor for CAD, but they were a significant factor for 3-VD and PAD independent of atherosclerotic risk factors. The odds ratios for 3-VD and PAD were 1.06 (95%CI = 1.01–1.11) and 1.07 (95%CI = 1.01–1.13) for a 100-pg/mL increase in betatrophin levels, respectively (p < 0.05).

Conclusion: Plasma betatrophin levels were associated with the presence and severity of CAD and PAD, suggesting betatrophin has a role in atherosclerosis.

Low Plasma Levels of Fibroblast Growth Factor-21 in Patients with Peripheral Artery Disease

AIM

Fibroblast growth factor-21 (FGF-21) is a metabolic regulator with beneficial effects on glucolipid metabolism. Since FGF-21 has lipid-lowering, anti-inflammatory and anti-oxidant properties, it may play a protective role against atherosclerosis. However, blood FGF-21 levels in coronary artery disease (CAD) or peripheral artery disease (PAD) have not been elucidated.

METHODS

We measured plasma FGF-21 levels in 417 patients undergoing coronary angiography, who also had ankle-brachial index test for PAD screening.

RESULTS

CAD was found in 224 patients (1-vessel [1-VD], n=92; 2-vessel [2-VD], n=65; 3-vessel disease [3-VD], n=67). No significant difference was found in the FGF-21 levels between 224 patients with CAD and 193 without CAD (median 26.0 vs. 25.9 pg/mL). FGF-21 levels in 4 groups of CAD(-), 1-VD, 2-VD, and 3-VD were 25.9, 37.2, 19.4, and 0.0 pg/mL. FGF-21 tended to be highest in 1-VD and lowest in 3-VD, but the difference did not reach statistical significance. PAD was found in 38 patients. Compared to the 379 patients without PAD, 38 with PAD had CAD more often (87% vs. 50%), especially 3-VD (P＜0.001). FGF-21 levels were lower in patients with PAD than in those without PAD (0.0 vs. 30.7 pg/mL, P＜0.02). In multivariate analysis, the FGF-21 level was an independent factor for PAD, but not for CAD. Odds ratio for PAD was 2.13 (95%CI=1.01-4.49) for a low FGF-21 level (＜15.6 pg/mL).

CONCLUSION

No significant difference was found in the FGF-21 levels between patients with and without CAD. However, FGF-21 levels were low in patients with PAD, and were a factor for PAD independent of atherosclerotic risk factors.

Low Levels of Plasma Osteoglycin in Patients with Complex Coronary Lesions

Aim: Osteoglycin is one of proteoglycans that are biologically active components of vascular extracellular matrix. However, the role of osteoglycin in atherosclerosis remains unclear.

Methods: We investigated plasma osteoglycin levels and the presence, severity, and lesion morphology of coronary artery disease (CAD) in 462 patients undergoing elective coronary angiography.

Results: Of 462 patients, 245 had CAD. Osteoglycin levels were higher in patients with CAD than without CAD (median 29.7 vs. 25.0 ng/mL, P < 0.05). However, osteoglycin levels did not differ among patients with one-vessel, two-vessel, or three-vessel disease (30.8, 30.6, and 29.4 ng/mL, respectively) and did not correlate with the number of stenotic segments. Among 245 CAD patients, 41 had complex coronary lesions, and 70 had total occlusion, of whom 67 had good collateralization. Between 70 patients with occlusion and 175 without occlusion, osteoglycin levels did not differ (30.4 vs. 29.5 ng/mL). Notably, osteoglycin levels were lower in 41 patients with complex lesions than in 204 without such lesions (24.2 vs. 31.6 ng/mL, P < 0.02). In multivariate analysis, osteoglycin levels were an independent factor for complex lesion but not for CAD. Odds ratio for complex lesion was 0.80 (95%CI = 0.67–0.96) for each 10 ng/mL increase in osteoglycin levels (P < 0.02).

Conclusion: Although plasma osteoglycin levels were high in patients with CAD, they did not correlate with the severity of CAD and were not an independent factor for CAD. Notably, osteoglycin levels were low in patients with complex lesions and were a factor for complex lesions, suggesting that osteoglycin plays a role in coronary plaque stabilization.

Tumor rejection by disturbing tumor stroma cell interactions

The stroma of solid tumors is a complex network of different cell types. We analyzed stroma cell interactions in two tumor models during cyclophosphamide (Cy)-induced tumor rejection. In growing tumors, tumor infiltrating macrophages (TIMs) produced interleukin (IL)-10. Beginning 6 h after Cy-treatment T cells in the tumor were inactivated and TIMs switched to interferon (IFN)-gamma production. Both, IL-10 production before and IFN-gamma production after Cy-treatment by TIMs required T cells. With the same kinetics as TIMs started to produce IFN-gamma the tumor vasculature was destroyed which required IFN-gamma receptor expression on host but not tumor cells. These events preceded hemorrhagic necrosis and residual tumor cell elimination by T cells. Together, T cells regulate the function of TIMs and tumor rejection can be induced by disturbing the stroma network.

Terminal deoxynucleotidyltransferase is negatively regulated by direct interaction with proliferating cell nuclear antigen

BACKGROUND

The repertoires of Ig and TcR are generated by a combinatorial rearrangement of variable (V), diversity (D), and joining (J) segments (V(D)J recombination) in B- and T-cells. Terminal deoxynucleotidyltransferase (TdT) adds extra nucleotides (N nucleotides) at the junctions of the gene segments to enhance the Ig and TcR genes diversity. Using an anti-TdT antibody column, TdT has been purified as a member of a megadalton protein complex from rat thymus. The N region would be synthesized with the large protein complex.

RESULTS

The cDNAs for proliferating cell nuclear antigen (PCNA) were isolated by yeast two-hybrid screening as the gene products which directly interacted with TdT. The interaction between PCNA and TdT was confirmed by co-immunoprecipitation, both in vitro and in vivo. TdT binds directly to a PCNA trimer, as shown by gel filtration. TdT interacts with PCNA in its DNA polymerization domain (DPD), but not in its BRCA-1 C-terminal (BRCT) domain. TdT activity was reduced to 17% of the maximum value by TdT/PCNA complex formation.

CONCLUSION

TdT interacts directly with PCNA through its DPD. A functional consequence of this interaction is the negative regulation of TdT activity. These findings suggest that TdT catalyses the addition of N nucleotides under the negative control of PCNA during V(D)J recombination.

Terminal deoxynucleotidyltransferase directly interacts with a novel nuclear protein that is homologous to p65

BACKGROUND

Terminal deoxynucleotidyltransferase (TdT) is a DNA polymerase that enhances Ig and TcR gene diversity in the N region in B- and T-cells. TdT is found as a member of a large protein complex in the lysate of the thymocytes. To elucidate the molecular mechanism of the synthesis of the N region, we first attempted to isolate the genes with products that are interacting directly with TdT.

RESULTS

Using a yeast two-hybrid system, we isolated a cDNA clone encoding a novel nuclear protein that interacts with TdT. This protein was designated as TdT interacting factor 1 (TdIF1). TdIF1 has a high degree of homology to the transcription factor p65, which belongs to the nuclear receptor superfamily. TdIF1 contains HMG-I and HMG-Y DNA binding domains (AT-hooks) and can bind to single- and double-stranded DNA. TdT and TdIF1 were co-eluted at position 232 kDa by gel filtration of MOLT4 lysate. TdIF1 can enhance TdT activity fourfold in vitro assay system using oligo(dT)16 as primers.

CONCLUSIONS

TdIF1 binds directly to TdT, both in vitro and in vivo. TdIF1 and TdT exist as the members of a 232 kDa protein complex. TdIF1 can enhance TdT activity maximum fourfold in vitro assay system, suggesting that it positively regulates the synthesis of the N region during V(D)J recombination in the Ig and TcR genes.

T helper cell type 1-associated and cytotoxic T lymphocyte-mediated tumor immunity is impaired in interleukin 4-deficient mice

It is widely accepted that cellular immune responses are induced by CD4(+) T helper 1 (Th1) cells secreting interleukin (IL)-2 and interferon (IFN)-gamma. Tumor immunity is often mediated by cytotoxic T lymphocytes (CTLs) whose activation is supported by Th1 cytokines. Since IL-4 directs Th2 development and has been shown to inhibit Th1-dominated responses, we assumed that IL-4-deficient (IL-4(-/-)) mice would develop vigorous CTL-mediated tumor immunity compared with IL-4-competent (IL-4(+/+)) mice. Surprisingly, IL-4(-/-) mice were severely impaired to develop tumor immunity to both a mammary adenocarcinoma line and a colon carcinoma line. The lack of tumor immunity in IL-4(-/-) mice was associated with reduced IFN-gamma production, diminished levels of tumor-reactive serum IgG2a, and undetectable CTL activity, indicating a defective Th1 response in the absence of endogenous IL-4. Anti-IL-4 monoclonal antibody blocked tumor immunity in IL-4(+/+) mice when administered at the time of immunization but not at the time of challenge. Additionally, tumor immunity could be induced in IL-4(-/-) mice, if IL-4 was provided by gene-modified cells together with immunizing tumor cells. These results demonstrate that tumor immunity requires IL-4 in the priming phase for the generation of effector cells rather than for their maintenance and exclude secondary, developmental defects in the "knockout" strain. Together, our results demonstrate a novel and previously unanticipated role of IL-4 for the generation of Th1-associated, CTL-mediated tumor immunity.

B cells inhibit induction of T cell-dependent tumor immunity

Cytotoxic T lymphocyte (CTL) mediated tumor immunity against major histocompatibility antigen (MHC) class I-positive but class II-negative tumors often requires help from CD4+ T cells. These CD4 cells are activated by MHC class II-positive cells that present tumor derived antigens. Considering that different antigen presenting cells, such as B cells, macrophages and dendritic cells compete for antigen and influence the outcome of an immune response, we analyzed tumor immunity in B cell-deficient mice. These mice appear normal with regard to T cell immunity and tolerance to some pure foreign antigens. We show here that the low immunogenicity of tumors is caused by B cells whose presence in the priming phase results in disabled CD4+ T cell help for CTL mediated tumor immunity. Instead, in the presence of B cells, a non-protective humoral immune response is induced. Our results may explain the enigmatic observation that tumor-reactive antibodies occur frequently in cancer patients.