The impact of end-stage kidney disease on mortality in patients after acute myocardial infarction: A nationwide study.

BACKGROUND: This study aimed to evaluate the impact of end-stage kidney disease (ESKD) on mortality in patients with first-time acute myocardial infarction (AMI). METHODS: This was a retrospective nationwide cohort study. Patients diagnosed with first-time AMI between January 1, 2000, and December 31, 2012, were included. All patients were followed-up until death or December 31, 2012, whichever occurred first. A one-to-one propensity score matching technique was used to match patients with ESKD to those without ESKD of similar sex, age, comorbidities, and coronary intervention (including percutaneous coronary intervention [PCI] and coronary artery bypass grafting [CABG]). Kaplan-Meier cumulative survival curves were constructed to compare AMI patients with and without ESKD. RESULTS: A total of 186 112 patients were enrolled and 8056 patients with ESKD were identified. Propensity score matched 8056 patients without ESKD were included in the comparison. Overall, the 12-year mortality rate was significantly higher in patients with ESKD than in those without ESKD (log-rank p < 0.0001), including the sex, age, and PCI and CABG subgroups. In Cox proportional-hazard regression analysis, ESKD was an independent risk factor for mortality after patients suffered from first-time AMI (hazard ratio, 1.77; 95% CI, 1.70-1.84; p < 0.0001). A forest plot for subgroup analysis revealed that in AMI patients, ESKD had a higher impact on mortality in male; younger age; without comorbidities such as hypertension, diabetes mellitus, peripheral vascular disease, heart failure, cerebrovascular accident, and chronic obstructive pulmonary disease; and receiving PCI and CABG subgroups. CONCLUSION: ESKD significantly increases the mortality risk in patients with first-time AMI, including both sexes, different ages, and whether PCI or CABG was performed. In patients with AMI, ESKD has a high impact on mortality in male, younger age, without comorbidities, and those undergoing PCI and CABG.

Long-term outcomes after stent implantation in very small vessel coronary artery disease.

BACKGROUND: Percutaneous coronary interventions (PCI) in very small vessel lesions represent an intriguing aspect of coronary artery disease (CAD). Uncertainty still exists in stent implantation in very small caliber vessels. This study aimed to evaluate the long-term outcomes of patients treated with 2.0-mm drug-eluting stent (DES). METHOD: This retrospective observational study included 134 patients undergoing PCI with 2.0-mm zotarolimus DES from December 2016 to May 2020. The primary endpoint was major adverse cardiovascular events (MACE) at 2-year follow-up, which was composed of all-cause mortality, target vessel myocardial infarction, and ischemia-driven target lesion revascularization. Multiple logistic regression analysis was used to identify the independent predictors of MACE, and odds ratios (OR) and 95% confidence intervals (CI) were calculated. RESULT: The lesions were diffuse (mean length 20.9 ± 5.51 mm) and belong to type B2/C lesions (90.3%). On follow-up, the MACE rate was 20.1% and mostly driven by late lumen loss demanding revascularization (11.9%). In multivariable analysis, chronic kidney disease (CKD) (OR: 4.291, 95% CI: 1.574-11.704, p = 0.004) and calcified lesions (OR: 3.688, 95% CI: 1.311-10.371, p = 0.013) were the independent predictors of subsequent cardiovascular events, whereas statin was associated with better outcomes (OR: 0.335, 95% CI: 0.119-0.949, p = 0.040). CONCLUSION: 2.0-mm DES is a feasible option for treating very small vessel CAD in complex lesions. Patients with CKD and calcified lesions carry the hazard of worse outcomes, and careful consideration should be taken before stenting in this high-risk population.

Impact of medications on outcomes in patients with acute myocardial infarction and chronic obstructive pulmonary disease: A nationwide cohort study.

BACKGROUND: Various inhaled bronchodilators have been associated with cardiovascular safety concerns. This study aimed to investigate the long-term impact of chronic obstructive pulmonary disease (COPD) and the safety of COPD medications in patients after their first acute myocardial infarction (AMI). METHODS: This nationwide cohort study was conducted using data from the Taiwan National Health Insurance Research Database. Patients hospitalized between 2000 and 2012 with a primary diagnosis of first AMI were included and divided into three cohorts (AMI, ST-elevation myocardial infarction [STEMI], and non-STEMI [NSTEMI]). Each cohort was propensity score matched (1:1) with patients without COPD. A Cox proportional hazards regression model was used to estimate hazard ratios (HRs) with 95% CIs. RESULTS: A total of 186 112 patients with AMI were enrolled, and COPD was diagnosed in 13 065 (7%) patients. Kaplan-Meier curves showed that patients with COPD had a higher mortality risk than those without COPD in all cohorts (AMI, STEMI, and NSTEMI). The HR of mortality in AMI, STEMI, and NSTEMI patients with COPD was 1.12 (95% CI, 1.09-1.14), 1.20 (95% CI, 1.14-1.25), and 1.07 (95% CI, 1.04-1.10), respectively. Short-acting inhaled bronchodilators and corticosteroids increased mortality risk in all three cohorts. However, long-acting inhaled bronchodilators reduced mortality risk in patients with AMI (long-acting beta-agonist [LABA]: HR, 0.87; 95% CI, 0.81-0.94; long-acting muscarinic antagonist [LAMA]: HR, 0.82; 95% CI, 0.69-0.96) and NSTEMI (LABA: HR, 0.89; 95% CI, 0.83-0.97; LAMA: HR, 0.80; 95% CI, 0.68-0.96). CONCLUSION: This study demonstrated that AMI patients with COPD had higher mortality rates than those without COPD. Using inhaled short-acting bronchodilators and corticosteroids reduced survival, whereas long-acting bronchodilators provided survival benefits in AMI and NSTEMI patients. Therefore, appropriate COPD medication for acute AMI is crucial.

Reverse structural left atrial remodeling and atrial tachycardia in patients with repeat ablation for atrial fibrillation.

BACKGROUND: Catheter ablation has been evolved to a cornerstone in the therapy of atrial fibrillation (AF); however, atrial tachycardias (AT) after AF ablation are still an important issue. Besides the electrical recurrence of atrial tachyarrhythmia after ablation, left atrial (LA) remodeling has received attention as a consequence of AF. OBJECTIVE: The aim of this study is to evaluate predictors for AT recurrence and LA remodeling in patients with repeat AF ablation procedures. METHODS AND RESULTS: One hundred thirteen patients who underwent repeat AF ablation with 3D electro-anatomical mapping system were evaluated. Mean age was 63.1 ± 9.3 years, and 2.3 ± 0.5 ablation procedures were performed during a time period of 22 [IQR 7;48] months. Reverse structural LA remodeling (LA volume decreased more than 15%) was observed in 25 (22.1%) patients. LA volume index (LAVI) during first procedure was the only predictor for positive reverse structural LA remodeling (hazard ratio (HR): 1.03, 95% CI: 1.00-1.07, p = .036) in multivariate analysis. Fifty-nine (52.2%) patients experienced only AF and 54 (47.8%) patients AT after first procedure. Female gender (HR: 5.21, 95% CI: 1.66-18.08, p = .006), LAVI (HR: 1.06, 95% CI: 1.02-1.11, p = .008) and LA scar percentage (HR: 1.08, 95% CI: 1.02-1.17, p = .019) were independent significant predictors for AT recurrence in multivariate analysis. CONCLUSIONS: Reverse structural LA remodeling occurred in a quarter of patients with repeat ablation procedures for AF. Only larger LAVI during first procedure predicted reverse structural LA remodeling. Half of the patients experienced AT between first and last ablation procedure. Female gender, larger LAVI and larger scar area were significant predictors for AT after catheter ablation for AF.

The Association between Iron-Deficiency Anemia (IDA) and Septic Arthritis (SA): The Real-World Data.

Background and Objectives: Iron-deficiency anemia (IDA) could predispose the afflicted individuals to various infections and musculoskeletal disorders. This study attempted to investigate the association between IDA and septic arthritis (SA), a musculoskeletal disease. Materials and Methods: We investigated all the eligible subjects in the Taiwanese longitudinal health insurance database (LHID) between 2000 and 2012. Subjects with the diagnosis of IDA (International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM): 280) were allocated to the IDA cohort. The control subjects were randomly matched to every subject with IDA coding by age and sex at the 1:4 ratio. All of the recruited subjects were followed since the index date to the onset of SA (ICD-9-CM: 711.0), withdrawal from the insurance (including death), or 31 December 2013. Results: The cumulative incidence of SA was assessed. We showed that the cumulative incidence of SA was higher in the IDA cohort than in the control cohort (p-value < 0.0001). After adjustment of the comorbidities, the IDA patients had a 2.53-fold risk of SA compared to control subjects (aHR = 2.53, 95% CI = 1.89−3.38). Conclusions: IDA was associated with an increased risk of SA.

Quality care in ST-segment elevation myocardial infarction.

Over the past decades, the treatment of ST-segment elevation myocardial infarction (STEMI) has been redefined with the incorporation of evidence from multiple clinical trials. Recommendations from guidelines are updated regularly to reduce morbidity and mortality. However, heterogeneous care systems, physician perspectives, and patient behavior still lead to a disparity between evidence and clinical practice. The quality of care has been established and become an integral part of modern healthcare in order to increase the likelihood of desired health outcomes and adhere to professional knowledge. For patients with STEMI, measuring the quality of care is a multifactorial and multidimensional process that cannot be estimated solely based on patients' clinical outcomes. The care of STEMI is similar to the concept of "the chain of survival" that emphasizes the importance of seamless integration of five links: early recognition and diagnosis, timely reperfusion, evidence-based medications, control of cholesterol, and cardiac rehabilitation. Serial quality indicators, reflecting the full spectrum of care, have become a widely used tool for assessing performance. Comprehension of every aspect of quality assessment and indicators might be too demanding for a physician. However, it is worthwhile to understand the concepts involved in quality improvement since every physician wants to provide better care for their patients. This article reviews a fundamental approach to quality care in STEMI.

Pulmonary arterial hypertension in the elderly population.

Pulmonary arterial hypertension (PAH) was a disease predominantly affecting young females about 40 years ago; however, it has been increasingly diagnosed in elderly individuals. Few studies have investigated the features of elderly patients with PAH. This review provides an overview of the characteristics of elderly patients with PAH compared to young patients. The examination of the changing demographics of the population with PAH revealed that the mean age has increased over the years. In addition, the investigation into the diagnostic challenges in elderly patients with PAH revealed the difficulty in differentiating PAH from pulmonary hypertension secondary to diastolic heart failure. Moreover, it was noted that elderly patients underwent combination drug regimens less frequently and exhibited poorer treatment responses than young patients. Finally, it was found that elderly PAH patients experienced poorer survival than young patients. The differences among five survival prediction models and their applicability in predicting the prognosis of PAH patients are discussed.

The influence of testosterone on the risk of cardiovascular events after percutaneous coronary intervention.

Methods: Between 2015 and 2018, 580 men undergoing PCI at a tertiary referral hospital were divided into low (<3.25 ng/mL) and normal (≥3.25 ng/mL) testosterone groups. Major adverse cardiovascular event (MACE) was defined as the composite outcome of CV death, myocardial infarction, and target lesion revascularization/target vessel revascularization (TLR/TVR) during up to 48 months follow-up after PCI. Results: There were 111 and 469 patients in the low and normal testosterone groups, respectively, with the overall MACE rate of the former being higher than the latter (26.13% vs. 13.01%, p = 0.0006). Moreover, the overall TLR/TVR (20.72% vs. 11.73%, p = 0.0125) and myocardial infarction (3.6% vs. 0.85%, p = 0.0255) rates were significantly higher in those with low serum testosterone who also had a shorter average event-free survival analysis of MACE (25.22 ± 0.88 months) than those with normal testosterone levels (35.09 ± 0.47 months, log-rank p = 0.0004). Multiple logistic regression demonstrated an association between low serum testosterone (<3.25 ng/mL) and a higher MACE rate [odds ratio: 2.06, 95% confidence interval (CI) 1.21-3.51, p = 0.0081]. After adjusting for variables in a Cox regression model, hazard ratios (HRs) for MACE (HR: 1.88, 95% CI: 1.20-2.95, p = 0.0058) and TLR/TVR (HR: 1.73, 95% CI: 1.06-2.83, p = 0.0290) rates were higher in the low testosterone group than those in the normal testosterone group. Conclusion: Low serum testosterone concentrations were associated with a higher risk of MACE and TLR/TVR after PCI than those with normal testosterone levels.

The risk of stroke after acute myocardial infarction in patients with and without atrial fibrillation: A nationwide cohort study.

BACKGROUND: Acute myocardial infarction (AMI) and atrial fibrillation (AF) are risk factors for stroke. The risk of stroke after AMI may differ between patients with and without AF. The aim of this study was to evaluate the impact of AF on stroke in patients after the first AMI. METHODS: This was a retrospective, nationwide cohort study. Patients with a primary diagnosis of a first AMI between 2000 and 2012 were included. All patients were followed up until ischemic stroke or transient ischemic attack (TIA), or December 31, 2012, whichever occurred first. Kaplan-Meier cumulative survival curves were constructed to compare ischemic stroke or TIA between AMI patients with and without AF. RESULTS: A total of 170 472 patients were enrolled in this study. Among them, 8530 patients with AF were identified. The propensity score matching technique was used to match 8530 patients without AF of similar ages and sexes. Overall, the 12-year stroke rate was significantly higher in patients with AF than in those without AF (log-rank p < 0.001), including different sexes, ages, and interventional therapy subgroups. Patients with pre-existing AF had higher stroke rates than those with newly diagnosed AF in male sex, age below 65 years, and those receiving interventional therapy subgroups. In Cox proportional-hazard regression analysis, AF was an independent risk factor for stroke after the first AMI (hazard ratio, 1.67; 95% CI: 1.5-1.87). CONCLUSION: AF significantly increases stroke risk after the first AMI. In patients with AF, those with pre-existing AF have higher stroke risks in male sex, age below 65 years, and those with interventional therapy than those with newly diagnosed AF.

Comparison of Different Timing of Multivessel Intervention During Index-Hospitalization for Patients With Acute Myocardial Infarction.

Background: Many patients presenting with acute myocardial infarction (AMI) were found to have a multivessel disease. Uncertainty still exists in the optimal revascularization strategy in AMI patients. The purpose of this study was to assess the outcome of immediate multivessel revascularization compared with staged multivessel percutaneous coronary intervention (PCI) in patients with AMI. Method: This was a nationwide cohort study of 186,112 patients first diagnosed with AMI, 78,699 of whom received PCI for revascularization. Patients who received repetitive PCI during the index hospitalization were referred to as staged multivessel PCI. Immediate multivessel PCI was defined as patients with two-vessel PCI or three-vessel PCI during the index procedure. Cox proportional hazards regression models were performed to evaluate the different indicators of mortality risks in AMI. Result: Immediate multivessel PCI was associated with a worse long-term outcome than staged multivessel PCI during the index admission (log-rank P < 0.001). There was a higher incidence of stroke in patients with multivessel PCI during hospitalization. In Cox analysis, immediate multivessel PCI was an independent risk factor for mortality compared to those with staged multivessel PCI, regardless of the type of myocardial infarction. Conclusion: This study demonstrated that performing immediate multivessel PCI for AMI may lead to worse long-term survival than staged multivessel PCI. Our findings emphasized the importance of PCI timing for non-infarct-related artery stenosis and provided information to supplement current evidence.

Impact of statin on long-term outcome among patients with end-stage renal disease with acute myocardial infarction (AMI): a nationwide case-control study.

BACKGROUND: Use of statin has been associated with reduced risk of cardiovascular diseases events and mortality. However, in patients with end-stage renal disease (ESRD), the protective effects of statin are controversial. To evaluate the impact of chronic statin use on clinical outcomes of patients with acute myocardial infarction (AMI) with ESRD. METHODS: We enrolled 8056 patients with ESRD who were initially diagnosed and admitted for first AMI from Taiwan's National Health Insurance Research Database. Of which, 2134 patients underwent statin therapy. We randomly selected and use age, sex, hypertension, diabetes mellitus (DM), peripheral vascular diseases (PVD), heart failure (HF), cerebrovascular accidents (CVA), chronic obstructive pulmonary disease, matched with the study group as controls (non-stain user). We compared the effects of statin use in term of all-cause death among patients with AMI with ESRD. RESULTS: Statin use resulted in a significantly higher survival rate in patients ith AMI with ESRD compared with non-statin users. After adjusted the comorbidities the male patients and patients with DM, PVD, HF and CVA had lower long-term survival rate (all p<0.001). Patients who underwent percutaneous coronary intervention (p<0.001), ACE inhibitors/angiotensin II receptor blockers (p<0.001), ß receptor blockers (p<0.001) and statin therapy (p=0.007) had better long-term survival rate. Patients with AMI with ESRD on statin therapy exhibited a significantly lower risk of mortality compared with non-statin users (p<0.0001). CONCLUSION: Among patients with ESRD with AMI, statin therapy was associated with reduced all-cause mortality.

Comparison of effects of triple antithrombotic therapy and dual antiplatelet therapy on long-term outcomes of acute myocardial infarction.

Warfarin is an alternate choice for patients who are not eligible for non-vitamin K oral anticoagulants after acute myocardial infarction (AMI). This study aimed to compare the long-term outcome of triple antithrombotic therapy (TAT) with that of dual antiplatelet therapy (DAPT) after AMI. This was a nationwide, propensity score-matched, case-control study of 186,112 first AMI patients, of whom 2,825 received TAT comprising aspirin, clopidogrel, and warfarin. Propensity score matching in a ratio of 1:4 by age, sex, comorbidities, and treatment was adopted, Finally, 2,813 AMI patients and 11,252 matched controls that were administered TAT and DAPT (aspirin and clopidogrel), respectively, were included in our analysis. The 12-year overall survival rate did not differ between both strategies (P = .3167). TAT was beneficial in old age (hazard ratio [HR] = 0.92), female sex (HR = 0.86), atrial fibrillation (AF) (HR = 0.80), hypertension (HR = 0.92), cerebrovascular accident (HR = 0.90), and in the absence of percutaneous coronary intervention (HR = 0.79). TAT reduced the rate of recurrent myocardial infarction (P = .0108) but did not affect the rate of stroke (P = .4867), gastrointestinal bleeding (P = .3889), or intracranial hemorrhage (ICH) (P = .3449). TAT reduces the incidence of recurrent myocardial infarction and does not increase the risk of major bleeding, while compared to DAPT.

Combination Therapy with Dipyridamole and Clopidogrel for Secondary Stroke Prevention in Aspirin-Intolerant Patients After Myocardial Infarction: Results of a Nationwide Case-Control Study.

BACKGROUND AND PURPOSE: Combination therapy with dipyridamole and clopidogrel in stroke prevention and long-term outcomes in aspirin-intolerant patients with acute myocardial infarction (AMI) and previous stroke are unknown. This nationwide study analyzed the impact of dipyridamole and clopidogrel on secondary stroke prevention and long-term outcomes in aspirin-intolerant stroke patients after AMI. METHODS: This was a nationwide, case-control study involving 186,112 first AMI patients, 78,607 of whom had a previous history of stroke. In the final analysis, we included 4637 patients taking clopidogrel alone and 208 patients using a combination of clopidogrel and dipyridamole. RESULTS: The 12-year survival rate was not different between clopidogrel and clopidogrel-dipyridamole groups (log-rank p = 0.6247). Furthermore, there were no differences in event-free survival after stroke (log-rank p = 0.6842), gastrointestinal (GI) bleeding (log-rank p = 0.9539), or intracerebral hemorrhage (ICH; log-rank p = 0.6191) between the two groups. Dipyridamole did not contribute significantly to AMI survival (hazard ratio 0.98, 95% confidence interval 0.84-1.15), and did not show benefits in any of the subgroups regardless of sex, age (younger or older than 75 years), comorbidities, percutaneous coronary intervention, or medications. CONCLUSION: No differences were observed in the 12-year survival rate between clopidogrel and clopidogrel-dipyridamole groups. The two groups had balanced event-free survival in recurrent stroke, ICH, GI bleeding, and myocardial infarction.

Comparison of long-term mortality in patients with acute myocardial infarction associated with or without sepsis.

OBJECTIVES: Although the association between systemic infection and cardiovascular events has been identified, uncertainty remains regarding the incidence and prognosis of sepsis in acute myocardial infarction (AMI). The purpose of this research was to assess the impact of sepsis on survival after first AMI. METHODS: This was a nationwide cohort study involving the analysis of data from the Taiwan National Health Insurance Research Database for the period 2000-2012, for patients with a primary diagnosis of first AMI. Among the 186112 prospective patients, sepsis was diagnosed in 13065 (7.0%). The propensity score matching technique was used to match 13065 controls to the patients with sepsis and AMI with similar baseline characteristics. Cox proportional hazards regression models, including sepsis, percutaneous coronary intervention (PCI), and comorbidities, were performed to further evaluate the different influences on the mortality risk in patients hospitalized for first AMI. RESULTS: Overall, the 12-year survival rate was lower in AMI patients with sepsis than in those without sepsis (log rank p-value <0.001); this was also shown in the different age and sex groups. The AMI patients with sepsis had a longer length of hospital stay than those without sepsis (32.5days vs. 11.74 days, p<0.001). In the Cox proportional hazards regression analysis, sepsis was an independent risk factor for mortality in patients after AMI (hazard ratio 1.78; 95% confidence interval 1.72-1.83). Interventional management with PCI or coronary artery bypass grafting improved survival in both the sepsis and non-sepsis patients after first AMI. CONCLUSIONS: In conclusion, sepsis significantly increased the mortality risk of patients after first AMI. PCI may improve the long-term survival of patients in comparison to those managed conservatively.

Tacticity effects in side-chain photoluminescent polymers.

Stereoregular side-chain photoluminescent (PL) polymers were synthesized via the stereospecific polymerization of 9,9-dibutyl-2-(4-vinylphenyl)-9H-fluorene. The resulting isotactic, syndiotactic and atactic poly(9,9-dibutyl-2-(4-vinylphenyl)-9H-fluorene) polymers were used as stereoregular polymer samples for examining the configurational tacticity effect on their PL properties. Our results revealed a unique tacticity-dependent effect as observed by an obvious red-shifting of the PL emission by increasing the degree of isotacticity of these stereoregular polymers; despite the ultraviolet spectra of these polymers exhibited similar absorption patterns. This study provides a new structural design for the syntheses of PL polymers.

NADH/NADPH bi-cofactor-utilizing and thermoactive ketol-acid reductoisomerase from Sulfolobus acidocaldarius.

Ketol-acid reductoisomerase (KARI) is a bifunctional enzyme in the second step of branched-chain amino acids biosynthetic pathway. Most KARIs prefer NADPH as a cofactor. However, KARI with a preference for NADH is desirable in industrial applications including anaerobic fermentation for the production of branched-chain amino acids or biofuels. Here, we characterize a thermoacidophilic archaeal Sac-KARI from Sulfolobus acidocaldarius and present its crystal structure at a 1.75-Å resolution. By comparison with other holo-KARI structures, one sulphate ion is observed in each binding site for the 2'-phosphate of NADPH, implicating its NADPH preference. Sac-KARI has very high affinity for NADPH and NADH, with K M values of 0.4 µM for NADPH and 6.0 µM for NADH, suggesting that both are good cofactors at low concentrations although NADPH is favoured over NADH. Furthermore, Sac-KARI can catalyze 2(S)-acetolactate (2S-AL) with either cofactor from 25 to 60 °C, but the enzyme has higher activity by using NADPH. In addition, the catalytic activity of Sac-KARI increases significantly with elevated temperatures and reaches an optimum at 60 °C. Bi-cofactor utilization and the thermoactivity of Sac-KARI make it a potential candidate for use in metabolic engineering or industrial applications under anaerobic or harsh conditions.

Ventricular arrhythmias originating from the cardiac crux and the basal inferior segment of the interventricular septum in the patients with structural heart diseases: characteristics, mapping, and electrophysiological properties.

PURPOSE: There are few reports describing ventricular arrhythmias (VAs) from the crux and the corresponding endocardial site, i.e., the basal inferior segment of the interventricular septum (IVS). We aimed to investigate a distinct clinical group of VAs arising from the endocardium at this area in patients with structural heart diseases (SHD). METHODS: We included 17 patients with SHD and clinically documented VAs. Thirteen patients underwent endocardial mapping only. Three patients underwent both epicardial and endocardial approaches and one had only epicardial mapping. Eighteen VAs were identified, 14 focal and 4 reentrant VAs, confirmed by entrainment. RESULTS: There were 2 VAs from the crux, 5 VAs from the corresponding endocardial site in the right ventricle (RV), and 11 from the site in the left ventricle (LV). Compared with the VAs from RV endocardium, VAs from LV endocardium had a higher R wave in V3 than V2 (V2R/V3R ratio, 1.83 ± 0.84 vs. 0.86 ± 0.38, P = 0.008) and a higher V3 transition ratio percentage (2.16 ± 2.07 vs. 0.58 ± 0.62, P = 0.008). Combining all 16 patients with endocardial mapping, there were also lower bipolar voltages (1.21 ± 1.05 vs. 3.10 ± 2.65 mv, P < 0.0001), lower unipolar voltages (4.05 ± 1.92 vs. 5.75 ± 2.90 mv, P < 0.0001), and longer local electrocardiogram (EGM) lateness (157.6 ± 47.9 vs.140.3 ± 52.5 ms, P = 0.0001) in the dominant chambers. CONCLUSIONS: In VAs from the crux and the corresponding endocardial site, the complete ECG V2R/V3R ratio and V3 transition ratio percentage could differentiate the VAs from the RV or LV endocardium. The lower unipolar, bipolar voltage mapping, and longer EGM lateness are helpful to identify the abnormal substrate in the endocardium in these patients.

The Arginine Pairs and C-Termini of the Sso7c4 from Sulfolobus solfataricus Participate in Binding and Bending DNA.

The Sso7c4 from Sulfolobus solfataricus forms a dimer, which is believed to function as a chromosomal protein involved in genomic DNA compaction and gene regulation. Here, we present the crystal structure of wild-type Sso7c4 at a high resolution of 1.63 Å, showing that the two basic C-termini are disordered. Based on the fluorescence polarization (FP) binding assay, two arginine pairs, R11/R22' and R11'/R22, on the top surface participate in binding DNA. As shown in electron microscopy (EM) images, wild-type Sso7c4 compacts DNA through bridging and bending interactions, whereas the binding of C-terminally truncated proteins rigidifies and opens DNA molecules, and no compaction of the DNA occurs. Moreover, the FP, EM and fluorescence resonance energy transfer (FRET) data indicated that the two basic and flexible C-terminal arms of the Sso7c4 dimer play a crucial role in binding and bending DNA. Sso7c4 has been classified as a repressor-like protein because of its similarity to Escherichia coli Ecrep 6.8 and Ecrep 7.3 as well as Agrobacterium tumefaciens ACCR in amino acid sequence. Based on these data, we proposed a model of the Sso7c4-DNA complex using a curved DNA molecule in the catabolite activator protein-DNA complex. The DNA end-to-end distance measured with FRET upon wild-type Sso7c4 binding is almost equal to the distance measured in the model, which supports the fidelity of the proposed model. The FRET data also confirm the EM observation showing that the binding of wild-type Sso7c4 reduces the DNA length while the C-terminal truncation does not. A functional role for Sso7c4 in the organization of chromosomal DNA and/or the regulation of gene expression through bridging and bending interactions is suggested.

Impact of aortic encroachment to left atrium on non-pulmonary vein triggers of atrial fibrillation.

BACKGROUND: Aortic dilatation was frequently observed in patients with atrial fibrillation (AF) and non-pulmonary vein (PV) triggers are important for mapping and ablation of AF. We hypothesized that the aortic encroachment area over left atrium (LA) could contribute to the local substrate characteristics. METHODS: We studied 32 consecutive patients of AF (age=57.34±8.07, male=30), including 26 paroxysmal and 6 persistent AFs. Anatomic relationship between LA and aorta, and electrophysiological characteristics of the encroachment areas were investigated. IRB approval was taken. RESULTS: The LA bipolar voltage (mean 0.49±0.26mV) was lower at aortic encroached area compared to global LA (mean 1.52±0.48mV) and it was statistically significant (p<0.001). There was a linear correlation between the voltages of LA and distance from the aorta to the aortic encroachment area of LA (p<0.001, R=0.616). Non-PV triggers were observed in 34.37% (n=11) of total patients. The initiation of AF in aortic encroached area was seen in 45.45% (n=5) of non-PV trigger and 15.62% of total patients. All the patients were followed up for 6months and 4 (14.81%) out of 27 patients without trigger at aortic encroached site of LA and 1 (20%) out of 5 patients with trigger at aortic encroached site of LA had recurrence of AF. CONCLUSION: The aorta contributed to low voltages on its encroachment area over the anterior wall of LA. Non-pulmonary vein triggers originating from the aortic encroachment area were found in 15.62% of total patients. Careful evaluation of the anatomical relationship between LA and aorta is important during AF ablation for a better long term outcome.

Crystal Structure Analysis of the Repair of Iron Centers Protein YtfE and Its Interaction with NO.

Molecular mechanisms underlying the repair of nitrosylated [Fe-S] clusters by the microbial protein YtfE remain poorly understood. The X-ray crystal structure of YtfE, in combination with EPR, magnetic circular dichroism (MCD), UV, and (17) O-labeling electron spin echo envelope modulation measurements, show that each iron of the oxo-bridged Fe(II) -Fe(III) diiron core is coordinatively unsaturated with each iron bound to two bridging carboxylates and two terminal histidines in addition to an oxo-bridge. Structural analysis reveals that there are two solvent-accessible tunnels, both of which converge to the diiron center and are critical for capturing substrates. The reactivity of the reduced-form Fe(II) -Fe(II) YtfE toward nitric oxide demonstrates that the prerequisite for N2 O production requires the two iron sites to be nitrosylated simultaneously. Specifically, the nitrosylation of the two iron sites prior to their reductive coupling to produce N2 O is cooperative. This result suggests that, in addition to any repair of iron centers (RIC) activity, YtfE acts as an NO-trapping scavenger to promote the NO to N2 O transformation under low NO flux, which precedes nitrosative stress.