Association between Serum TNF-α Levels and Recurrent Spontaneous Miscarriage: A Meta-analysis

Most recurrent spontaneous miscarriages (RSMs) are attributed to 'unexplained' factors, the majority of which are immune factors. Furthermore, clinically, only a small number of RSM patients get early diagnosis by testing for antiphospholipid antibodies, whereas most of the patients, present no specific diagnostic indicators. We performed a meta-analysis of observational studies to detect the association between RSM and TNF-α levels. We searched PubMed, EMBase, ScienceDirect, Web of Science, and Chinese databases (including: Wanfang Data, CNKI, and VIP databases) for articles published up to 2014. Of the 151 initially identified studies, 11 case-control studies with 1371 patients were finally analyzed. Overall, baseline TNF-α levels were higher in patients than in controls. The standardized mean difference of the TNF-α levels of the patients was 2.82 units (95% confidence interval 1.57-4.06) and the overall effect z-score was 4.42 (P < 0.0001). The heterogeneity test revealed significant differences among individual studies (P = 0.000, I(2)  = 98.7%). Serum TNF-α levels were significantly increased in patients relative to those in controls. The heterogeneity could be attributed to the differences in the detection methods and sampling times used in the different studies.

A functional variant in the promoter region regulates the C-reactive protein gene and is a potential candidate for increased risk of atrial fibrillation

OBJECTIVES

In a large population-based cohort, the level of C-reactive protein (CRP) in patients at baseline predicts an increased risk of future development of atrial fibrillation (AF). The mechanism of this increased risk is unknown. Furthermore, both the molecular effects of CRP on atrial myocytes and fibroblasts and whether genetic variants in the CRP gene predispose to AF are also unknown.

METHODS

A genetic association study between CRP gene polymorphisms and AF was performed in two independent populations (I: 100 AF patients and 101 controls; II: 348 AF patients and 356 controls), with functional studies to elucidate the mechanism of association.

RESULTS

Three polymorphisms (T-861C, A-821G and C-390A/C-390T) were found in the 1-kb promoter of CRP. A triallelic polymorphism (C-390A/C-390T) captured all haplotype information and determined the CRP gene promoter activity and the plasma CRP level, and was in nearly complete linkage disequilibrium with G1059C polymorphism in exon 2. The -390A variant was associated with a higher CRP gene promoter activity, a higher plasma CRP level and a higher risk of AF. Patients with AF also had a higher plasma CRP level than controls. CRP significantly increased the inward L-type calcium current in atrial myocytes with no changes in other ionic currents. CRP did not affect the expressions of type I alpha 1 (COL1A1), type III alpha 1 (COL3A1) and type 1 alpha 2 (COL1A2) procollagens in atrial fibroblasts.

CONCLUSION

A CRP gene promoter triallelic polymorphism was associated with CRP gene promoter activity, determined the plasma level of CRP, and predicted the risk of AF. The mechanism of this may be via augmention of calcium influx by CRP in atrial myocytes, but not because of atrial fibrosis.

C-reactive protein but not atrial dysfunction predicts recurrences of atrial fibrillation after cardioversion in patients with preserved left ventricular function

OBJECTIVES

Maintenance of sinus rhythm after cardioversion of atrial fibrillation is a major clinical challenge also in patients with preserved left ventricular function. Subclinical inflammation and atrial strain have been recognized as important contributors to atrial fibrillation onset and perpetuation. Aim of the study was to compare the predictive role of C-reactive protein (CRP) and indices of atrial dysfunction in relation to subacute arrhythmic recurrence rate in patients with persistent atrial fibrillation and normal left ventricular ejection fraction (LVEF).

METHODS

We studied 53 patients with a mean LVEF of 58.7 +/- 6%. Left atrial diameter and area, left atrial auricle emptying velocity, N-terminal pro-b-type natriuretic peptide (NT-proBNP) and CRP levels were determined few hours before electrical cardioversion. NT-proBNP and CRP levels were also measured 1 h and 3 weeks after cardioversion.

RESULTS

Subacute atrial fibrillation recurrences were documented in 18 (33.9%) patients. Whereas none of the parameters reflecting atrial dysfunction predicted arrhythmic outcome, higher CRP levels (>3.0 mg/l) were significantly associated with atrial fibrillation recurrences [odds ratio (OR): 1.6; 95% confidence interval (CI): 1.4-2.5; P = 0.031]. No changes in CRP levels were evident after cardioversion independently of underlying rhythm. On the contrary, NT-proBNP levels, which were correlated with left atrial auricle emptying velocity, significantly decreased only in patients who maintained sinus rhythm (from 638 +/- 329 to 295 +/- 261 pg/ml; P < 0.001).

CONCLUSION

The present study demonstrates that in patients with persistent atrial fibrillation and preserved LVEF, CRP level is an independent predictor of atrial fibrillation subacute recurrence rate, whereas none of the indices of atrial dysfunction is associated with arrhythmic outcome. NT-proBNP levels reflect, instead, the hemodynamic alterations secondary to arrhythmia presence.

Meta-analysis of association between C-reactive protein and immediate success of electrical cardioversion in persistent atrial fibrillation

Current evidence links atrial fibrillation (AF) to the inflammatory state. Also, increased C-reactive protein (CRP) levels have been associated with greater risk of recurrence of AF after successful electrical cardioversion (EC). We conducted a meta-analysis of observational studies to examine the association between baseline CRP levels and the immediate success of EC in persistent AF. We searched the literature published November 2007 or earlier. In addition, a manual search was performed using all review articles on this topic, reference lists of studies, and abstracts from conference reports. Of the 342 initially identified studies, 6 prospective observational studies with a combined 366 patients (297 with successful and 69 with failed EC) were analyzed. Overall, CRP levels were greater in patients with failed EC. The standardized mean difference in the CRP levels between patients with successful and those with failed EC was -0.41 units (95% confidence intervals -0.68 to -0.14) and the Z score for overall effect was 2.98 (p=0.003). The heterogeneity test showed that there were no significant differences between the individual studies (p=0.36; I(2)=9.1%). In conclusion, our meta-analysis suggests that increased CRP levels are associated with greater risk of EC failure. CRP assessment before cardioversion may provide prognostic information regarding the success of the procedure.

Preoperative statin therapy is not associated with a decrease in the incidence of postoperative atrial fibrillation in patients undergoing cardiac surgery

BACKGROUND

Atrial fibrillation (AF) after cardiac surgery is associated with significant morbidity. We investigated whether preoperative statin therapy was associated with decreased incidence of postoperative AF in patients undergoing cardiac surgery, including isolated valve surgery and patients with low ejection fraction (EF).

METHODS

A retrospective study of consecutive patients without history of AF (n = 4044) who underwent cardiac surgeries at St. Luke's Episcopal Hospital (Houston, TX), from January 1, 2003, through April 30, 2006, was conducted. Postoperative AF was assessed by continuous telemetry monitoring during hospitalization for cardiac surgery.

RESULTS

A total of 2096 patients (52%) received preoperative statins. Atrial fibrillation occurred in 1270 patients (31.4% in both the statin and nonstatin groups). In multivariate regression analysis, age >65 years, history of valvular heart disease, rheumatic disease, pulmonary disease, and New York Heart Association class III/IV were independent predictors of increased risk, whereas female sex was associated with decreased risk. Preoperative statin therapy was not associated with decreased risk in the entire cohort (odds ratio [OR] 1.13, 95% confidence interval [CI] 0.98-1.31) or in subgroups undergoing isolated coronary artery bypass grafting (OR 1.16, 95% CI 0.97-1.43), isolated valve surgery (OR 1.09, 95% CI 0.81-1.46), or both (OR 1.09, 95% CI 0.72-1.65), or the subgroup with EF <35% (OR 1.23, 95% CI 0.84-1.82). After propensity score analysis (n = 867 patients in each group), preoperative statin therapy was not associated with decreased AF incidence (OR 1.14, 95% CI 0.92-1.41).

CONCLUSIONS

Preoperative statin therapy was not associated with decreased incidence of postoperative AF in patients undergoing cardiac surgery, including patients with low EF.

[Inflammatory state in patients with atrial fibrillation before and after electrical cardioversion]

OBJECTIVE

To assess the inflammatory state in patients with persistent atrial fibrillation and to determine the predictive value in the success of cardioversion and recurrence at 30 days.

DESIGN

Prospective observational case-control study.

PATIENTS

We included consecutively 49 patients with atrial fibrillation previously to scheduled electrical cardioversion in Coronary Care Unit. Clinical and echocardiographic variables were registered and High-sensivity C-reactive protein, interleukin-1beta, interleukin-6 and Tumour Necrosis Factor-alpha were measured. At 30-days follow-up, rhythm and biomarkers were reassessed. As control groups, we recruited 27 healthy volunteers and 16 patients matched for age, gender and cardiovascular risk factors.

RESULTS

Median age was 66 +/- 10 years and 38% were women. All the markers were higher in patients than in both control groups (p < 0.05). FNT-alpha and Interleukin-6 levels were higher in non-cardiovertors but only an enlarged atria was related to unsuccessful cardioversion (p = 0.036). High-sensivity C-reactive protein values in the higher cuartile tended to be related to recurrence of persistent atrial fibrillation (p = 0.06).

CONCLUSIONS

There is an increased inflammatory state in patients with atrial fibrillation. FNT-alpha and Interleukin-6 levels were increased in non-cardiovertors, but no biomarker was associated with success of cardioversion or rhythm state at 30-days. However, higher levels of hs-CRP showed a trend to be related to recurrence of atrial fibrillation.

Association between C-reactive protein and recurrence of atrial fibrillation after successful electrical cardioversion: a meta-analysis

OBJECTIVES

We conducted a systematic review and meta-analysis of observational studies to examine the association between baseline C-reactive protein (CRP) levels and the recurrence of atrial fibrillation (AF) after successful electrical cardioversion (EC).

BACKGROUND

Current evidence links AF to the inflammatory state. Inflammatory indexes such as CRP have been related to the development and persistence of AF. However, inconsistent results have been published with regard to the role of CRP in predicting sinus rhythm maintenance after successful EC.

METHODS

Using PubMed, the Cochrane clinical trials database, and EMBASE, we searched for literature published June 2006 or earlier. In addition, a manual search was performed using all review articles on this topic, reference lists of papers, and abstracts from conference reports. Of the 225 initially identified studies, 7 prospective observational studies with 420 patients (229 with and 191 without AF relapse) were finally analyzed.

RESULTS

Overall, baseline CRP levels were greater in patients with AF recurrence. The standardized mean difference in the CRP levels between the patients with, and those without AF was 0.35 units (95% confidence interval 0.01 to 0.69); test for overall effect z-score = 2.00 (p = 0.05). The heterogeneity test showed that there were significant differences between individual studies (p = 0.02; I(2) = 60.2%). Further analysis revealed that differences between the CRP assays possibly account for this heterogeneity.

CONCLUSIONS

Our meta-analysis suggests that increased CRP levels are associated with greater risk of AF recurrence, although there was significant heterogeneity across the studies. The use of CRP levels in predicting sinus rhythm maintenance appears promising but requires further study.