Clinical Study Of The Predictors Of Atrial Fibrillation Recurrence After Catheter Ablation

Background and objective：Although radiofrequency catheter ablation of atrial fibrillation(AF)is an effectiverhythm control strategy, there is a substantial recurrence rate[1,2]. Therefore, thedevelopment of clinical and electrophysiological predictors of recurrence after AF ablationmay reduce the number of unnecessary invasive procedures, the risk of complications, ormedical cost, and improve clinical outcomes of selected patients. Knowledge of thesepredictors would also contribute to a better understanding of AF pathophysiology. Althoughprevious reports have suggested various predictors, such as left atrial size[3], biomarkersand so on, the results are inconsistent. Our research includes two parts:(1) We collected andcollated the clinical data of hospitalized patients and then evaluated the related factorsinfluence curative effects of AF using catheter ablation in guidance of CARTO in order toprovide evidence for the selection of patients.(2) We researched internal or external medicalliterature about the association between C-reactive protein (CRP) and AF recurrence aftercatheter ablation, and then conducted a meta-analysis in order to make our study realisticand believable. Importantly, our researcher provides new evidence about this issue.MethodsPart1A retrospective analysis was carried out after clinical follow-up, divided patients intotwo groups: maintenance of sinus rhythm group and recurrence of AF group. The clinicaldata of two groups were analyzed 1. We selected hospitalized patients in our hospital from January2012to September2012who underwent catheter ablation in guidance of CARTO;2. The catheter ablation had been done by specialists.3. All patients were tested with preoperative “three great regular tests”,“bloodbiochemistry test”,“Transthoracic Echocardiography (TTE)”, electrocardiogram (ECG) and24hour holter monitoring.4. Monitoring of ECG, oxygen saturation and blood pressure a day after the catheterablation. On the first day gave patients “blood biochemistry test”, one the third to fifth dayafter operation, made the ECG and and24hour holter monitoring. Postoperative takewarfarin and amiodarone three months for paroxysmal AF, six months for persistent AF.5. All patients were followed in postoperative1month,3months,6months and12months, ask patients about their symptoms and collect the data of ECG and24hour holtermonitoring.Part2We conducted a meta-analysis about the association between CRP and AF recurrenceafter catheter ablation in order to evaluate the predictive value of CRP.1. We carefully searched PubMed, Embase, Medline, ISI Web of Knowledge, andScienceDirect databases.2. We searched database for original articles published before December31,2012toevaluate the associations between CRP and AF recurrence after catheter ablation.3. The medical subject headings and key words used for search were “C-reactiveprotein” and “atrial fibrillation”.4. To screen articles according to inclusion and exclusion criteria.5. To assess article quality according to Cochrane Reviewer’s Handbook6. All statistical analyses were conducted using Review Manager5.2(The CochraneCollaboration, Copenhagen, Denmark) and Stata11.0software (StataCorp, College Station,TX)ResultsPart11. This study included100patients, After9.82±1.26(6-12months) months of follow-up，there were71cases of sinus arrhythmia，29cases of AF recurrence.2. The results of univariate analysis by non-conditional logistic regression analysisshowed persistent AF, elevated high-sensitivity C-reactive protein(hs-CRP) levels,N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, enlarged Left atrial diameter(LAD), left atrial maximum volume index (LAVImax) and mitral regurgitation weresignificantly associated with AF recurrence(P<0.05).3. The results of multivariate analysis by non-conditional logistic regression analysisshowed elevated hs-CRP levels (HR:5.12；95%CI:1.87-14.06，P=0.002) and mitralregurgitation were independent predictors of AF recurrence. Baseline hs-CRP cansuccessfully predict AF recurrence with relatively high sensitivity and specificity.4. The hs-CRP level increased after catheter ablation, and the trend had significantlystatistical in two groups. Furthermore, the raising level(Δhs-CRP)has no significantlystatistical between two groups.Part21. Seven relevant studies involving526patients were included in our meta-analysis:179individuals were in AF-recurrence group, and347were in no AF-recurrence group.2. Four studies showed that greater baseline CRP was related to AF recurrence andanother three showed no association.3. Overall, there was significantly positive association between CRP concentration andAF recurrence from our meta-analysis (Z=3.70, P<0.001).4. On the subgroup analyses by sample, CRP concentration was greater in patients withAF recurrence both in the sample size less than100group (SMD:0.40,95%CI:0.14-0.66)and more than100group(SMD:1.08，95%CI:0.80-1.36). Furthermore, the largersample size showed the more obvious trend.5. On the subgroup analyses by ethnicity of population, greater CRP concentration hadassociation with post-ablation AF recurrence in Caucasians (SMD:0.39，95%CI:0.07-0.71)and Asians (SMD:0.84，95%CI:0.42-1.27).6. Heterogeneity test showed that there was moderate difference between individualstudies (P=0.006; I2=67%) and the sample size was the most probable origin of thisheterogeneity from meta-regression analysis.7. Publication bias analysis: Begg’s funnel plot and Egger’s test confirmed the absence of publication bias.Conclusions:1. The increasing hs-CRP levels and moderate and severe mitral regurgitation beforecatheter ablation represent high risk of AF recurrence.2. Baseline hs-CRP level can predict AF recurrence after catheter ablation withrelatively high sensitivity and specificity.3. Catheter ablation can cause inflammation, but the difference between inflammatoryresponse (Δ hs-CRP) had no significant statistical between two groups.4. The trend that elevated CRP lead to high risk of AF recurrence becomes moreobvious because of the larger sample size.5. The result that greater CRP concentration has association with post-ablation AFrecurrence hold true for Caucasians and Asians.