Impact of 12-Month Angioscopic Thrombi and Yellow Plaque After Drug-Eluting Stent Implantation.

BACKGROUND: Coronary angioscopy (CAS) has 2 unique abilities: direct visualization of thrombi and plaque color. However, in the recent drug-eluting stent (DES) era, serial CAS findings after DES implantation have not been fully elucidated. We investigated the impact of CAS findings after implantation of a polymer-free biolimus A9-coated stent (PF-BCS) or durable polymer everolimus-eluting stent (DP-EES).Methods and Results: We investigated serial CAS and optical coherence tomography (OCT) findings at 1 and 12 months in 99 patients who underwent PF-BCS or DP-EES implantation. We evaluated factors correlated with angioscopic thrombi and yellow plaque, and the clinical impact of both thrombi and yellow plaque at 12 months (BTY). The BTY group included 17 (22%) patients. The incidence and grade of thrombi and yellow plaque decreased from 1 to 12 months. Although no patients had newly appearing thrombi at 12 months, 2 DP-EES patients had newly appearing yellow plaque at 12 months. Multivariable analysis revealed HbA1c, minimum stent area, and adequate strut coverage were significant factors correlated with 12-month angioscopic thrombi, and DP-EESs were significantly correlated with 12-month yellow plaque. However, BTY was not correlated with clinical events. CONCLUSIONS: The management of diabetes, stent area, and adequate stent coverage are important for intrastent thrombogenicity and polymer-free stents are useful for stabilizing plaque vulnerability.

Risk factors for tachycardia-induced cardiomyopathy due to atrial fibrillation.

BACKGROUND: Tachycardia-induced cardiomyopathy (TIC) is a reversible cardiomyopathy with ventricular dysfunction caused by tachyarrhythmias. Notably, atrial fibrillation (AF) is the most common causal arrhythmia leading to TIC. However, the risk factors for the development of TIC due to AF remain unclear. This study aimed to identify the associated factors of TIC due to AF. METHODS: Persistent AF patients with heart rate (HR) ≥100 beats per minute who underwent initial catheter ablation were enrolled in this study. TIC was diagnosed as left ventricular ejection fraction (LVEF) < 50% during AF rhythm, which was recovered after the restoration of sinus rhythm. Non-TIC was defined as LVEF ≥ 50% despite AF rhythm. The patient backgrounds were compared between the TIC group and the non-TIC group to reveal the contributing factors of TIC. RESULTS: The TIC group comprised 57 patients, while the non-TIC group consisted of 101 patients. The TIC group was younger than the non-TIC group (median 64 vs. 70, p = 0.006). Male sex was more frequent in the TIC group than the non-TIC group (82.5% vs. 58.4%, p = 0.003). HR was higher in the TIC group than in the non-TIC group (median 130 bpm vs. 111 bpm, p < 0.001). The number of smokers was significantly higher in the TIC group than in the non-TIC group (p < 0.001). Multivariable analysis demonstrated that higher HR (odds ratio [OR]: 1.74; 95% confidence interval [CI]: 1.37-2.21; p < 0.001) and current smokers (OR: 5.27; 95% CI: 1.60-17.4; p = 0.006) were the independent factors leading to TIC. CONCLUSION: Higher HR and current smokers were independent risk factors for the development of TIC due to AF.

Clinical Impact of Perfusion Balloon for ST-Segment Elevated Myocardial Infarction: RYUSEI Study.

Drug-eluting stents have significantly contributed to reducing mortality in patients with ST-segment elevation myocardial infarctions (STEMIs), but slow-flow/no-reflow phenomenon (SFNR) and in-stent restenosis are still clinical problems. In contrast, perfusion balloons (PBs) can compress thrombi and ruptured plaque for long inflation without ischemia and can be used as a delivery device for infusion of nitroprusside to distal risk area during ballooning. We conducted a Reduction of risk bY perfUsion balloon for ST-segment Elevated myocardial Infarction (RYUSEI) study to evaluate whether PBs before stenting are more effective than conventional stenting for STEMIs. We divided consecutive patients with STEMIs who underwent optical coherence tomography (OCT)-guided percutaneous coronary intervention into PB group who were treated with PBs (Ryusei; Kaneka Medix Corporation, Osaka, Japan) before stenting and the conventional percutaneous coronary intervention (CP) group. We compared clinical results including SFNR, OCT findings, and clinical events between the 2 groups. We finally analyzed 34 patients in PB group and 90 in CP group. After propensity score-matching, PB and CP groups consisted of 23 patients, respectively. In the propensity score-matched cohort, SFNR and maximum protrusion area detected by OCT were significantly lower (p = 0.047 and p = 0.019), and thrombolysis in myocardial infarction flow grade 3 was higher (p = 0.022) in the PB group than CP group. Kaplan-Meier analysis revealed a significantly better clinical outcome in PB group than CP group (p = 0.038). In conclusion, the RYUSEI study revealed a pre-stent lesion modification in addition to nitroprusside infusion using PB is useful to achieve better clinical courses in STEMI patients.

Changes in QRS morphology during antidromic atrioventricular reentrant tachycardia.

We report a case of a 44-year-old male who underwent an electrophysiological study for symptomatic supraventricular tachycardia (SVT) with wide QRS complex. The SVT was diagnosed as an antidromic atrioventricular reentrant tachycardia (AVRT) via antegrade conduction of left-sided accessory pathway (AP). However, the QRS morphology changed during the SVT, and then the SVT was terminated spontaneously. The mapping of AP was performed during sinus rhythm, and the radiofrequency application successfully eliminated the AP, which rendered tachycardias non-inducible. This was a rare case of antidromic AVRT during which the QRS morphology changed.

Impact of residual induction number of non-pulmonary vein foci on the 2-year outcomes in patients with paroxysmal atrial fibrillation.

BACKGROUND: Residual non-pulmonary vein (PV) foci are significantly associated with atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI). However, we previously reported among patients with non-PV foci induced only once, none experienced AF recurrence. Thus, we aimed to investigate the correlation between the residual induction number of non-PV foci and ablation outcome in paroxysmal AF patients. METHODS AND RESULTS: We investigated 55 paroxysmal AF patients with residual non-PV foci after PVI and ablation of non-PV-foci. Study patients were classified into the residual one-time induction of non-PV foci (residual OTI-nPVF) group (n = 23) and residual repeatedly induced non-PV foci (residual RI-nPVF) group (n = 32). Furthermore, the residual RI-nPVF group was divided into the low inducibility group (n = 10) and high inducibility group (n = 22) according to the presence or absence of non-PV foci provoked by two sets of drug induction tests (non-PV foci inducibility). In addition, the latter was divided into the ablation group (n = 14) or observation group (n = 8). The 2-year AF recurrence-free rate in the residual RI-nPVF group was significantly lower compared to the residual OTI-nPVF group (53% vs. 90%, p = 0.018). There was no significant difference of the 2-year AF recurrence-free rates in the inducibility of non-PV foci (p = 0.913) and the presence or absence of ablation (p = 0.812) in the residual RI-nPVF group. CONCLUSIONS: Among paroxysmal AF patients, the presence of residual RI-nPVF was associated with higher AF recurrence compared to residual OTI-nPVF. Furthermore, within residual RI-nPVF subgroup, non-PV foci inducibility or ablation of some residual RI-nPVF did not affect ablation outcome.

Predictors of 30-day survival after emergent percutaneous coronary intervention following ventricular tachyarrhythmias complicating acute myocardial infarction.

BACKGROUND: Little has been reported on the predictors of 30-day survival after emergent percutaneous coronary intervention (PCI) following life-threatening ventricular tachyarrhythmias associated with acute myocardial infarction (AMI). METHODS: We analyzed 55 consecutive patients who underwent an emergent PCI after ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT) complicating AMI between September 2014 and March 2023 in our hospital. These patients were categorized into two groups: survival group (S group) who survived >30 days after the emergent PCI and death group (D group) who died by 30 days after the emergent PCI. We compared the patient characteristics, coronary angiographic findings, and PCI procedures between the two groups. RESULTS: S group consisted of 40 patients. In the univariate analysis, absence of diabetes mellitus, presence of immediate cardiopulmonary resuscitation (CPR), low arterial lactate, and single-vessel coronary artery disease (CAD) were associated with 30-day survival after the emergent PCI (P = 0.048, P < 0.001, P = 0.009, and P = 0.003, respectively). In the multivariate analysis, presence of immediate CPR and single-vessel CAD were independently associated with 30-day survival after the emergent PCI (P = 0.023 and P = 0.032, respectively). CONCLUSIONS: Immediate CPR and single-vessel CAD were significant predictors of 30-day survival after the emergent PCI following VF or pulseless VT complicating AMI. Absence of diabetes mellitus and low arterial lactate were associated with 30-day survival in the univariate analysis.

Prognostic Comparison of Octogenarian vs. Non-Octogenarian With Acute Decompensated Heart Failure　- AURORA Study.

BACKGROUND: Acute decompensated heart failure (ADHF) is the main cause of hospitalization and death of octogenarians, but no data on the 1-year post-discharge mortality rate. We evaluated the clinical status and predictors of 1-year mortality in octogenarians with ADHF.Methods and Results: From the AURORA (Acute Heart Failure Registry in Osaka Rosai Hospital) study, we examined 1,246 hospitalized ADHF patients. We compared the in-hospital mortality rate and the proportion of heart failure (HF) with preserved ejection fraction (HFpEF) between octogenarians and non-octogenarians. After discharge we compared the 1-year mortality rate between these groups, and we also evaluated the predictors of death in both groups. The proportion of HFpEF among the in-hospital deaths of octogenarians was significantly higher than in non-octogenarians (46.2% vs. 15.0%, P=0.031). The 1-year mortality rate after discharge was significantly higher in the octogenarians than non-octogenarians (P=0.014). Multivariable Cox regression analysis revealed that albumin ≤3.0 g/dL and antiplatelet agents were useful predictors of 1-year death after discharge of octogenarians whereas chronic kidney disease was a predictor in the non-octogenarians. CONCLUSIONS: The proportion of HFpEF among in-hospital deaths of octogenarians with ADHF was high as compared with non-octogenarians. When octogenarians with ADHF have severe hypoalbuminemia and antiplatelet agents, early nutritional and medical interventions after discharge may be important to improve the 1-year prognosis.

Clinical Impact of Cryoballoon Ablation for Paroxysmal Atrial Fibrillation in Patients With Enlarged Left Atrium.

The impact of cryoballoon ablation (CBA) for atrial fibrillation (AF) in patients with enlarged left atrium (E-LA) has not been sufficiently clarified. A total of 306 patients underwent an initial CBA for paroxysmal AF between February 2017 and March 2022 in our hospital. These patients were categorized into 2 groups according to the preprocedural left atrium (LA) diameter (LAD): E-LA group with LAD ≥40 mm and normal LA (N-LA) group with LAD <40 mm. We compared late recurrence (LR, defined as a recurrence of atrial tachyarrhythmia more than 3 months after the ablation) between the 2 groups. In addition, we made a further classification of the E-LA group into a severely E-LA (SE-LA) group with LAD ≥50 mm and mildly enlarged LA (ME-LA) group with LAD <50 mm and compared LR in the SE-LA, ME-LA, and N-LA groups. In the patients who experienced a second ablation procedure owing to LR, subsequent recurrences were also evaluated. After initial CBA, there was no significant difference in recurrence-free survival between E-LA and N-LA groups (p = 0.447). In contrast, the SE-LA group showed the lowest incidence of recurrence-free survival in the SE-LA, ME-LA, and N-LA groups (p = 0.012). However, when we analyzed recurrences after the ablation including second ablation procedure, there were no significant differences in recurrence-free survival among these 3 groups (p = 0.103). In conclusion, patients with paroxysmal AF with enlarged LA showed favorable outcomes compared with those with N-LA after CBA.

Direct Comparison of Rotational vs Orbital Atherectomy for Calcified Lesions Guided by Optical Coherence Tomography.

BACKGROUND: There are several retrospective studies comparing rotational atherectomy (RA) and orbital atherectomy (OA), but all percutaneous coronary interventions (PCIs) in those studies were not performed under intracoronary imaging guidance. OBJECTIVES: This study sought to compare the efficacy and safety of optical coherence tomography (OCT)-guided PCI with RA vs OA. METHODS: The DIRO (To directly compare RA and OA for calcified lesions, a prospective randomized trial) trial was conducted. We enrolled patients with de novo calcified lesions (arc >180°) assessed by OCT or angiographically moderate or severe calcifications if the OCT catheter could not cross the lesion before any intervention. Eligible patients were randomly 1:1 allocated to lesion preparation with RA vs OA. Stent expansion was defined as the minimum stent area divided by the distal reference area multiplied by 100. Tissue modification was assessed using preatherectomy and postatherectomy OCT images. Procedural outcomes including periprocedural myocardial infarctions were evaluated. Furthermore, clinical events and vascular healing evaluated by OCT at 8 months postprocedure were assessed. RESULTS: The stent expansion was significantly greater in the RA group vs the OA group (99.5% vs 90.6%; P = 0.02). The maximum atherectomy area was significantly larger in the RA group than in the OA group (1.34 [IQR: 1.02-1.89] mm2 vs 0.83 [IQR: 0.59-1.11] mm2; P = 0.004). The procedural outcomes and clinical events at 8 months did not differ between the groups. The vascular healing was sufficient in both groups. CONCLUSIONS: The prospective randomized DIRO trial revealed that RA could produce a more favorable tissue modification, which may lead to a larger stent expansion than OA in heavily calcified lesions.

Impact of a Novel Score to Predict Left Ventricular Diastolic Dysfunction After Catheter Ablation of Nonparoxysmal Atrial Fibrillation With Preserved Ejection Fraction.

The impact of catheter ablation of atrial fibrillation (AFCA) on left ventricular (LV) diastolic function is still unknown. This study aimed to develop a novel risk score to predict LV diastolic dysfunction (LVDD) 12 months after AFCA (12-month LVDD) and to evaluate whether the risk score was associated with cardiovascular events (cardiovascular death, transient ischemic attack/stroke, myocardial infarction, or heart failure hospitalization). We studied 397 patients with nonparoxysmal AF with preserved ejection fraction who underwent initial AFCA (age: 69 years, women: 32%). LVDD was diagnosed if more than 2 of 3 variables (average E/e' ratio >14, septal e' velocity <7 cm/s or lateral e' velocity <10 cm/s, and tricuspid valve regurgitation velocity >2.8 m/s) were present. The 12-month LVDD was observed in 89 patients (23%). A total of 4 preprocedural variables (woman, average E/e' ratio ≥9.6, age ≥74 years, and left atrial diameter ≥50 mm [WEAL]) were identified as predictors of 12-month LVDD on multivariable analysis. We developed a WEAL score. The prevalence of 12-month LVDD increased as WEAL scores increased (p <0.001). There was a statistically significant difference in cardiovascular events-free survival between those at high risk (WEAL score: 3 or 4) and those at low risk (WEAL score: 0, 1, or 2). (86.6% vs 97.2%, log-rank p = 0.009). The WEAL score before AFCA is useful to predict 12-month LVDD after AFCA in patients with nonparoxysmal AF with preserved ejection fraction and is associated with cardiovascular events after AFCA.

Predictors and outcomes of tricuspid regurgitation improvement after radiofrequency catheter ablation for persistent atrial fibrillation.

INTRODUCTION: Little has been reported on the predictors and outcomes of improvement of tricuspid regurgitation (TR) after radiofrequency catheter ablation (RFCA) for persistent atrial fibrillation (AF). METHODS: We enrolled 141 patients with persistent AF and moderate or severe TR assessed by transthoracic echocardiography (TTE) who underwent an initial RFCA between February 2015 and August 2021. These patients underwent follow-up TTE at 12 months after the RFCA, and were categorized into two groups based on the improvement (defined as at least one-grade improvement of TR) and non-improvement of TR: IM group and Non-IM group, respectively. We compared the patient characteristics, ablation procedures, and recurrences after the RFCA between the two groups. In addition, we examined the major event (defined as admission for heart failure or all-cause death) more than 12 months after the RFCA. RESULTS: IM group consisted of 90 patients (64%). A multivariate analysis revealed that age <71 years old and absence of late recurrence (LR, defined as recurrence of atrial tachyarrhythmia between 3 and 12 months after the RFCA) were independently associated with the improvement of TR after the RFCA. Furthermore, IM group had the higher incidence of major event-free survival than Non-IM group. CONCLUSIONS: Relatively young age and absence of LR were good predictors of improvement of TR after the RFCA for persistent AF. In addition, the improvement of TR was related to better clinical outcomes.

Early vascular healing of ultra-thin strut polymer-free sirolimus-eluting stents in acute coronary syndrome: USUI-ACS study.

Ultra-thin strut polymer-free sirolimus-eluting stent (UPF-SES) have two novel characteristics, ultra-thin strut and polymer-free coating, which have the potential to achieve early re-endotherialization. However, a little is known whether early vascular healing of UPF-SES can be achieved in patients with acute coronary syndrome (ACS). The aim of this study was to evaluate the vascular healing after an implantation of UPF-SES in patients with ACS using optical coherence tomography (OCT) at 3 months after the stent implantation. From September 2020 and January 2021, a total of 31 consecutive patients presenting with ACS who underwent OCT-guided percutaneous coronary intervention (PCI) and 3 month follow-up OCT examination were enrolled in the USUI-ACS study. The endpoints of this study were neointimal strut coverage, malapposition, and mean neointimal hyperplasia (NIH) thickness at 3 month follow-up. Over a mean follow-up of 91 days after the initial PCI, the follow-up OCT was examined. The median percentage of covered struts was 98.4% and malapposed struts 0%, and the mean NIH thickness was 80 µm. UPF-SES exhibited an excellent early vascular healing at 3 months in patients with ACS.

Comparison of advanced generation cryoballoon ablation and ablation index-guided pulmonary vein isolation with non-pulmonary vein trigger induction test and additional ablation in paroxysmal atrial fibrillation.

BACKGROUND: An ablation index (AI)-guided pulmonary vein isolation (PVI) or 2nd generation cryoballoon (CB)-PVI has been shown to reduce the atrial fibrillation (AF) burden by 99% despite the absence of ablation of non-pulmonary vein (PV) triggers in patients with paroxysmal AF. The purpose of this study was to investigate the effects of PVI alone strategy using 2nd generation CB compared with AI-guided PVI with an additional induction test and subsequent AF trigger ablation. METHODS AND RESULTS: We investigated 223 patients with symptomatic paroxysmal AF who underwent an initial PVI between August 2018 and August 2020. The study patients were divided into 2 groups: CB-PVI without an induction test (CB-PVI alone group, n = 82) and AI-guided PVI with an induction test and subsequent additional ablation of non-PV triggers (AI-PVI plus group, n = 141). In the AI-PVI plus group, a total of 62 non-PV triggers were induced in 38 patients, and non-PV triggers in 22 patients were completely ablated. The procedure time and left atrium dwell time were significantly shorter in the CB-PVI alone group than AI-PVI plus group. There were no significant differences in the incidence of procedural complications between the 2 groups (P = 0.650). The AF free survival rate in the CB-PVI alone group and AI-PVI plus group was 80% vs. 80% at 24 months (P = 0.969). CONCLUSIONS: An PVI alone strategy using advanced generation CB did not differ in the clinical outcomes compared with an AI-guided PVI strategy with an induction test and subsequent ablation of non-PV triggers in the patients with paroxysmal AF.

Association of the -173 G/C polymorphism of the macrophage migration inhibitory factor gene with ulcerative colitis.

BACKGROUND: Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine and has been shown to be involved in the development of chronic murine colitis. In the +173 G/C polymorphism of the MIF gene, the presence of C creates the binding motif of activator protein 4. This study explored the association of this polymorphism with ulcerative colitis (UC). METHODS: Genotyping was carried out, with a tetra-primer polymerase chain reaction (PCR) method, for 659 DNA specimens from 438 healthy volunteers and 221 patients with UC. Genotype distribution between cases and controls and the association of patients' genotypes with clinical parameters were statistically evaluated. RESULTS: No significant difference in genotype distribution was found between UC patients and healthy controls. However, when the relation of the C/C genotype to clinical parameters in UC patients was evaluated by Fisher's exact test, it was found that the frequency of the C/C genotype was higher in patients with pancolitis type than in those with other types restricted to the distal or left-sided colon (odds ratio [OR], 10.781; 95% confidence interval [CI], 1.342-86.619; P = 0.0074). CONCLUSIONS: These data suggest that the MIF -173 G/C polymorphism may be related to the extent of disease in UC in a Japanese population.

Relationship between matrix metalloproteinase-7 and pit pattern in early stage colorectal cancer.

BACKGROUND: The surface pit pattern of early stage colorectal cancer changes with tumor growth and invasion. It was postulated by us that the expression of matrix metalloproteinase-7 is related to tumor invasiveness and disturbance of the pit pattern. METHODS: Sixty-eight colorectal epithelial tumors were examined, and the pit pattern was classified by stereoscopic microscopy. Immunostaining for matrix metalloproteinase-7 and its substrate laminin were performed. RESULTS: The rate of matrix metalloproteinase-7 positive staining was significantly higher for mucosal (70.6%) and submucosal cancer (80.0%) than for adenoma (18.6%) (p<0.0083). The rate of matrix metalloproteinase-7 positive specimens was significantly higher for type IV and type V compared with type III pit patterns. Where the tumor surface was positive for matrix metalloproteinase-7, expression of laminin was negative in 40% of specimens with a type IV pit pattern and 100% of those with the type V pit pattern. CONCLUSIONS: The results of this study indicate that expression of matrix metalloproteinase-7 is related to both the invasiveness of colorectal epithelial tumors and the disturbance of the pit pattern on the tumor surface.

Association between the interleukin-1 receptor antagonist polymorphism and ulcerative colitis with younger age at diagnosis.

The VNTR polymorphism in intron 2 of the interleukin-1 receptor antagonist (IL-1RA) gene has been shown associated with ulcerative colitis (UC) in some populations. This study aimed to assess the relationship between the IL-1RA polymorphism and UC in a Japanese population. Genotyping was carried out with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for 468 DNA specimens from 239 healthy volunteers and 229 patients with UC. Genotype distribution was compared between cases and controls, and association of patients' genotype with clinical parameters was evaluated. No significant difference of genotype distribution was found between UC patients and healthy controls. However, when the relation of the carriage rate of allele 2 with clinical parameters was evaluated by Fisher's exact test, it was found that the allele 2 carriage rate was higher in patients with lower ages at diagnosis (< 30) than those with higher ages (> or =30) (odds ratio (OR), 5.049; 95% confidence interval (CI), 1.667-15.288; P= 0.0020). In addition, it tended to be higher in patients with pancolitis type than those with other types restricted to the distal or left-sided colon (OR, 3.005; 95% CI, 1.186-7.616; P=0.0256). These data suggest that the IL-1RA polymorphism is associated with UC with younger age at diagnosis.

Simple genotype analysis of the Asp299Gly polymorphism of the Toll-like receptor-4 gene that is associated with lipopolysaccharide hyporesponsiveness.

A nonsynonymous single nucleotide polymorphism (Asp299Gly) in the Toll-like receptor-4 (TLR-4) gene affects the responsiveness to lipopolysaccharide in humans. To analyze this important polymorphism more efficiently, we developed a simple polymerase chain reaction (PCR) restriction length fragment polymorphism (RFLP) assay and examined the Asp299Gly allele frequency in a Japanese population. The PCR primer was designed with 1- or 2-bp mismatches, creating the recognition sequence for restriction enzyme BsaBI or BstXI, allowing RFLP analysis of the digested products. Genotyping was carried out with this assay for 275 DNA specimens from 107 healthy volunteers and 168 patients with various diseases, including ulcerative colitis (n = 86). The Asp299Gly allele of the TLR-4 gene was not detected in any of the specimens, suggesting that it is very rare in Japanese.

Polymorphisms of the IL-1beta and IL-1beta-inducible genes in ulcerative colitis.

BACKGROUND: Ulcerative colitis (UC) is a chronic disorder of undetermined etiology, but a genetic predisposition to UC is well recognized. Among cytokines induced in UC, interleukin 1 (IL-1) appears to have a central role because of its immunological upregulatory and proinflammatory activities. The aim of this study was to assess whether UC is associated with polymorphisms of the IL-1beta gene and three additional genes inducible with IL-1beta in Japanese subjects. METHODS: A total of 96 patients with UC and 106 ethnically matched controls were genotyped at polymorphic sites in IL-1beta, matrix metalloproteinase 1 (MMP-1), matrix metalloproteinase 3 (MMP-3), and inducible nitric oxide synthase (iNOS) genes, using polymerase chain reaction (PCR)-based methods. RESULTS: There was no significant difference in genotype distributions of IL-1beta, MMP-1, MMP-3, and iNOS genes between controls and UC patients in a Japanese population. Also, no significant association of those polymorphisms with various clinical parameters of the patients was found. However, concerning association of age at onset with clinical factors in UC, the frequency of pancolitis was significantly higher in UC patients with age at onset being less than 30 years than in those more than 30 years of age (P = 0.049). CONCLUSIONS: No association of the IL-1beta and three IL-1beta-inducible gene polymorphisms with UC was observed in a Japanese population.