Early and Late Results of Permanent Atrial Fibrillation Ablation Surgery in Aortic Valve and CABG Patients

Comparison of modified MAZE with minimally invasive monopolar ablation and traditional bipolar radiofrequency ablation in the treatment of atrial fibrillation

Background and aim of the study

Atrial fibrillation (AF) is the most common atrial arrhythmia. Our aim was to compare the outcomes of atrial fibrillation treatment with original modified minimally invasive MAZE using monopolar radiofrequency ablation (mi-MAZE) and open surgery MAZE using bipolar radiofrequency ablation (os-MAZE).

Methods

We searched the associated patients’ information on the medical record system of the First Affiliated Hospital, School of Medicine, Zhejiang University. Statistical Package for Social Sciences (SPSS) was used to analyse the data. The primary outcome is the atrial fibrillation ablation rate 3 months, 6 months, 12 months after operation. And secondary outcome is the postoperative quality of life.

Results

The mi-MAZE group included 42 patients and the os-MAZE group had 65 patients. Three months after surgery, we found that 31 patients (77.5%) in the mi-MAZE group were sinus rhythm and 44 (71.0%) recovered sinus rhythm in the os-MAZE group. We followed up these patients on the phone or in person and scored them on the SF-36 scale. The results were found to be 120.2 ± 8.10 vs 110.6 ± 6.58 (mi-MAZE vs os-MAZE, P < 0.001).

Conclusions

There was no significant difference of atrial fibrillation ablation rate (sinus rhythm recovery rate) between the mi-MAZE group and the os-MAZE group. The postoperative quality of life in mi-MAZE group was higher than that in os-MAZE group.

Levels of vitamin C In the blood plasma patients treated with coronary artery bypass grafting increases significantly after surgery

One strong risk factor of coronary artery disease (CAD), which affects the levels of vitamin C in the blood is cigarette smoking. The supplementary effects of coronary artery bypass grafting (CABG) is smoking cessation by patients. Therefore, the aim of this study was to examine the level of vitamin C in the blood plasma one day before and one month after CABG. Human blood were collected from 20 patients (men); 1day before and 1 month after CABG. All patients were smoker and after CABG they declared their not smoking. The concentration of vitamin C in the blood plasma was assayed by FIA method with spectrophotometric detection. The mean value of the vitamin C concentration 1day before CABG was 12.36±2.84μmol/L (mean±SD), 1 month after CABG 40.07±10.95μmol/L (mean±SD). The average increase in the concentration of vitamin C was 3.27±0.73 times (mean±SD) and showed significant positive correlations (Pearson r=0.657, p=0.002). It should be consider incorporating the recommendations of preoperative smoking cessation for at least one month prior to CABG and/or additional supplementation. In addition it would be relevant to monitor the level of vitamin C in the patients' blood in the preoperative period.

Effect of novel modified bipolar radiofrequency ablation for preoperative atrial fibrillation combined with off-pump coronary artery bypass grafting surgery

We described a novel modified bipolar radiofrequency (RF) ablation for preoperative atrial fibrillation (AF) combined with off-pump coronary artery bypass grafting (OPCABG) for patients with AF and coronary artery disease (CAD). The aim of this study was to assess the effect of this novel procedure and to determine whether it can eliminate AF for CAD patients. From January 2007 to June 2013, 45 patients (26 male patients) with AF (9 paroxysmal, 17 persistent, and 19 long-standing persistent) and CAD underwent the novel modified bipolar RF ablation combined with OPCABG in our department. After median sternotomy, the modified bipolar RF ablation and OPCABG were performed on beating heart without cardiopulmonary bypass. Pulmonary vein isolation and left atrium ablation were achieved using a bipolar RF champ. Mitral annular lesion and ganglionic plexus were ablated with a bipolar RF pen. The left atrial appendage was excluded using a surgical stapler. 24 h holter monitoring and echocardiography were performed at discharge and 3, 6, 12 months postoperatively as well as every year thereafter. The modified bipolar RF ablation and OPCABG were performed successfully in all patients. Mean AF ablation time was 33.6 ± 4.2 min, and mean OPCABG time was 87.6 ± 13.3 min. Mean postoperative hospital stay was 12.6 ± 5.5 days. The maintenance of sinus rhythm was 95.6 % (43/45) at discharge. There was no early death and permanent pacemaker implantation in perioperation. At a mean follow-up of 29.8 ± 10.2 months, 38 of 45 (84.4 %) patients were in sinus rhythm. Follow-up TTE at 6 months postoperatively showed that left atrial diameter was significantly reduced and left ventricular ejection fraction was significantly increased. The novel modified bipolar RF ablation procedure was safe, feasible and effective. It may be useful in selecting the best ablation approaches for patients with AF and CAD.

Guideline for the surgical treatment of atrial fibrillation

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and its prevalence is ∼1-2% of the general population, but higher with increasing age and in patients with concomitant heart disease. The Cox-maze III procedure was a groundbreaking development and remains the surgical intervention with the highest cure rate, but due to its technical difficulty alternative techniques have been developed to create the lesions sets. The field is fast moving and there are now multiple energy sources, multiple potential lesion sets and even multiple guidelines addressing the issues surrounding the surgical treatment of AF both for patients undergoing this concomitantly with other cardiac surgical procedures and also as stand-alone procedures either via sternotomy or via videothoracoscopic techniques. The aim of this document is to bring together all major guidelines in this area into one resource for clinicians interested in surgery for AF. Where we felt that guidance was lacking, we also reviewed the evidence and provided summaries in those areas. We conclude that AF surgery is an effective intervention for patients with all types of AF undergoing concomitant cardiac surgery to reduce the incidence of AF, as demonstrated in multiple randomized studies. There is some evidence that this translates into reduced stroke risk, reduced heart failure risk and longer survival. In addition, symptomatic patients with AF may be considered for surgery after failed catheter intervention or even as an alternative to catheter intervention where either catheter ablation is contraindicated or by patient choice.

How effective is bipolar radiofrequency ablation for atrial fibrillation during concomitant cardiac surgery?

A best evidence topic in cardiothoracic surgery was written according to a structured protocol. The question addressed was whether, in patients undergoing cardiac surgery, concomitant bipolar radiofrequency ablation had an acceptable success rate to justify the additional procedure. Altogether 263 papers were found using the reported search, of which 12 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. The consensus in the literature was that bipolar radiofrequency ablation was highly successful in restoring sinus rhythm. One meta-analysis of six non-randomized studies demonstrated that 76% of patients were in sinus rhythm compared with 16% in atrial fibrillation 3 months postoperatively. One randomized controlled trial found that the sinus rhythm conversion rate for any maze procedure was highly significant compared with the control group (P = 0.001). Another found that Cardioblate radiofrequency ablation was significantly better at restoring sinus rhythm at 1 year (75 vs 39% control, P = 0.019). Prospective studies showed a similar rate of sinus rhythm return at 1 year (89%). Notably some studies demonstrated a significant reduction in the New York Heart Association class when sinus rhythm was restored compared with those remaining in atrial fibrillation (P < 0.0001), demonstrating the value of this procedure beyond simply restoring sinus rhythm. In another study, the investigators found that both ablation and total procedure times were shorter with bipolar compared with monopolar ablation. These authors strongly recommend bipolar radiofrequency ablation due to a shorter procedure time, ability to avoid performing a standard left atriotomy and a greater guarantee of transmurality. With the current limited evidence, we conclude that bipolar radiofrequency ablation has a higher success rate in restoring sinus rhythm as an adjunct to cardiac surgery compared with no ablation for at least 1 year. The procedure had a high survival rate. There is randomized evidence to suggest the superiority of bipolar radiofrequency ablation over microwave ablation but limited evidence to suggest the superiority of bipolar over unipolar radiofrequency ablation. Factors found to be accurate predictors of ablation failure include a larger preoperative atrial diameter, permanent vs paroxysmal atrial fibrillation and longer duration of atrial fibrillation.