Safety of cardioversion in atrial fibrillation lasting less than 48 h without post-procedural anticoagulation in patients at low cardioembolic risk

Currently, there is no unified consensus on short-term anticoagulation after cardioversion of atrial fibrillation lasting less than 48 h in low-cardioembolic-risk patients. The aim of this study is to evaluate the rate of transient ischemic attacks, stroke and death in this subset of patients after cardioversion without post-procedural anticoagulation. In a prospective observational study, patients with recent-onset AF undergoing cardioversion attempts in the Emergency Department were evaluated over the past 3 years. Inclusion criteria were conversion to sinus rhythm, low thromboembolic risk defined by a CHA2DS2VASc score of 0-1 points for males (0-2 points for females aged over 65 years), and hospital discharge without anticoagulant treatment. Patients with severe valvular heart disease, underlying systemic causes of AF, and those discharged with anticoagulant therapy were excluded. The main outcomes measured were TIA, stroke and death at thirty days' follow-up after discharge. During the study period, 218 successful cardioversions, obtained both electrically and pharmacologically, were performed on 157 patients. One hundred and eleven patients were males (71%), the mean age was 55.2 years (±standard deviation 10.7), 99 patients (63%) reported a CHA2DS2VASc score of 0, and the remaining 58 (37%) had a risk profile of 1 point. Of these, latter 8 were females (5%) older than 65 years (risk score 2 points). At the thirty days outcome, none of the 150 enrolled patients who completed a follow-up visit has reported TIA or stroke, nor died, in the overall 211 successful cardioversions evaluated. In our study, the rate of thromboembolic events after cardioversion of recent-onset AF of less than 48 h duration, in patients with a 0-1 CHA2DS2VASc risk profile (females 0-2), appeared to be extremely low even in absence of post-procedural anticoagulation. These findings seem to confirm data from previous studies, and suggest that routine post-procedural short-term anticoagulation may be considered as an overtreatment in this very low-risk subset of patients.

ARFI elastography in patients with chronic autoimmune liver diseases: A preliminary study

OBJECTIVE

Acoustic radiation force impulse (ARFI) is a new software-based technique that evaluates liver stiffness during B-mode ultrasonography. The purpose of this study was to evaluate the accuracy of ARFI in distinguishing patients with chronic autoimmune liver disease from healthy subjects.

MATERIAL AND METHODS

We enrolled 9 adult patients (8 women, 1 man; age 48.1 ± 12.8 years) with chronic autoimmune disease (primary biliary cirrhosis (PBC, n = 3), autoimmune hepatitis (AIH, n = 2), primary sclerosing cholangitis (PSC, n = 1) and overlap syndromes, (n = 3) who underwent a liver biopsy and 11 healthy volunteers (age 34.7 ± 10.4 years; 7 women, 4 men). Liver stiffness was evaluated and expressed as the shear wave velocity (SWV) in m/sec. We used a US scanner Siemens-Acuson S2000, evaluating the right liver lobe and the left liver lobe.

RESULTS

THE SWV WAS SIGNIFICANTLY HIGHER IN CASES (RIGHT LOBE: 1.51 ± 0.44; left lobe: 1.57 ± 0.40) than in controls (right lobe: 1.08 ± 0.10; left lobe: 1.12 ± 0.13) (right lobe: P = 0.002; left lobe: P = 0.013). We found no significant correlation between right and left lobe SWVs in cases (P = 0.779) or controls (P = 0.385). The SWV cut-off that best distinguished cases from controls was 1.25 m/sec (accuracy: AUC=0.885; sensitivity: 70.6%; specificity: 95.5%).

CONCLUSIONS

ARFI elastography is a noninvasive ultrasonographic technique that can differentiate healthy subjects from patients with fibrotic stages of chronic liver disease.

Real-time elastography as a noninvasive technique for quantification of fibrosis in patients with chronic viral liver disease: Preliminary findings

INTRODUCTION

Real-time elastography (RTE) is a novel technique for measuring tissue elasticity. The aims of this study were to prospectively measure liver stiffness with RTE in patients with chronic viral hepatitis and to evaluate the possible correlation between RTE data and the extent of fibrosis based on liver biopsy findings (Ishak score).

MATERIAL AND METHODS

Between February and October 2011, 26 patients (18M, 8F, mean age 41 ± 13 [standard deviation], range 22-62) with chronic viral hepatitis were prospectively evaluated with ultrasonography (US) that included RTE. All patients then underwent US-guided percutaneous liver biopsy (right lobe) for evaluation of fibrosis. Examinations were performed with a iU22 scanner (Philips, Bothell, WA, USA); a convex transducer (C5-1) was used for the US examination, and a linear transducer (L12-5) for RTE. In the RTE images, relative tissue stiffness is expressed according to a color scale with soft areas represented in green/red and hard areas in blue. Patients were examined in the supine position in suspended normal respiration; three loops of 20 RTE frames were recorded for each case. For each patient, we calculated the mean strain ratio (MSR) for the 3 loops. The Spearman correlation coefficient was used to assess correlation between the ASR and fibrosis stage (F) reflected by the Ishak score.

RESULTS

The Spearman coefficient showed significant correlation between the MSR and F (Rho = 0.470, p = 0.015).

CONCLUSIONS

RTE appears to be a useful tool for noninvasive evaluation of fibrosis in patients with chronic viral hepatitis although these findings need to be confirmed in larger case series.

Liver HCV-antigens and steatosis in chronic hepatitis C: role of different genotypes

BACKGROUND

HCV infection is frequently associated with liver steatosis.

AIMS AND METHODS

We studied 126 frozen liver HCV positive specimens (genotype-3=27) without any features of metabolic syndrome, searching for a correlation between the number of HCV infected hepatocytes and the presence, amount and distribution of steatosis in relation to different genotypes.

RESULTS

Mean steatosis score was higher in genotype-3 with respect to non-3 (1.11 vs 0.66, p=0.022). HCV-antigens were detected by an immunoperoxidase technique in 91/126 (72.2%) cases. A significant correlation between the number of HCV-antigen positive cells and the degree of liver steatosis was observed in genotype-3 (p=0.01) but not in non-3 patients, matched for sex and age. Steatotic cells usually outnumbered HCV-infected cells. Steatosis was observed both in HCV-antigen positive and negative hepatocytes, and HCV-antigens were detected in both hepatocytes with and without steatosis: while no lobular codistribution was found in genotype non-3, in genotype-3 steatosis and HCV-antigens were usually found in the same areas.

CONCLUSION

Our data support the role of HCV-antigen liver expression in the pathogenesis of steatosis in genotype-3, however, since the presence of HCV-antigens is not directly related to steatosis within single hepatocytes, an indirect mechanism might be operative too.

Antibodies to SS-A/Ro-52kD and centromere in autoimmune liver disease: a clue to diagnosis and prognosis of primary biliary cirrhosis

BACKGROUND

Primary biliary cirrhosis (PBC) may be associated with various rheumatological disorders.

AIM

To investigate the frequency and significance of 'rheumatological' antinuclear antibodies in the field of autoimmune chronic liver disease, with special regard to PBC.

METHODS

We studied 105 patients with PBC, 162 autoimmune liver disease controls (type 1 and 2 autoimmune hepatitis, primary sclerosing cholangitis), 30 systemic lupus erythematosus and 50 blood donors. Sera were tested for the presence of antibodies to extractable nuclear antigens (anti-ENA) by counterimmunoelectrophoresis, enzyme-linked and immunoblot (IB) assay, and for the presence of anti-centromere antibodies (ACA) by indirect immunofluorescence on HEp-2 cells and IB.

RESULTS

The overall prevalence of IB-detected anti-ENA in PBC (30%) was higher than in type 1 autoimmune hepatitis (2.5%, P < 0.0001), type 2 autoimmune hepatitis (0%, P < 0.0001) and primary sclerosing cholangitis (11.5%, P = 0.006) and lower than in systemic lupus erythematosus (53%, P = 0.03). The most frequent anti-ENA reactivity in PBC was anti-SSA/Ro-52kD (28%). ACA were detected by IB in 21% PBC patients and never in the other subjects (P < 0.0001). Anti-SS-A/Ro/52kD positive PBC patients had at the time of diagnosis a more advanced histological stage (P = 0.01) and higher serum levels of bilirubin (P = 0.01) and IgM (P = 0.03) compared with negative ones.

CONCLUSIONS

In the autoimmune liver disease setting, anti-SS-A/Ro-52kD and ACA have a high specificity for PBC and can thus be of diagnostic relevance in anti-mitochondrial antibodies negative cases. If confirmed in further studies with adequate follow-up, anti-SS-A/Ro-52kD antibodies might identify PBC patients with a more advanced and active disease.

Replacement of histidine 340 with alanine inactivates the group A Streptococcus extracellular cysteine protease virulence factor

Streptococcus pyogenes expresses a highly conserved extracellular cysteine protease that is a virulence factor for invasive disease, including soft tissue infection. Site-directed mutagenesis was used to generate a His340Ala recombinant mutant protein that was made as a stable 40-kDa zymogen by Escherichia coli. Purified His340Ala protein was proteolytically inactive when bovine casein and human fibronectin were used as substrates. Wild-type 28-kDa streptococcal protease purified from S. pyogenes processed the 40-kDa mutant zymogen to a 28-kDa mature form, a result suggesting that the derivative protein retained structural integrity. The data are consistent with the hypothesis that His340 is an enzyme active site residue, an idea confirmed by recent solution of the zymogen crystal structure (T. F. Kagawa, J. C. Cooney, H. M. Baker, S. McSweeney, M. Liu, S. Gubba, J. M. Musser, and E. N. Baker, Proc. Natl. Acad. Sci. USA 97:2235-2240, 2000). The data provide additional insight into structure-function relationships in this S. pyogenes virulence factor.