Effectiveness of the maze procedure using cooled-tip radiofrequency ablation in patients with permanent atrial fibrillation and rheumatic mitral valve disease
University of São Paulo, San Paulo, São Paulo, Brazil Circulation
(Impact Factor: 14.43).
09/2005; 112(9 Suppl):I20-5. DOI: 10.1161/CIRCULATIONAHA.104.526301
Although the Cox-Maze III procedure is effective for treating permanent atrial fibrillation (AF), its high complexity limits its use. The Saline-Irrigated Cooled-tip Radiofrequency Ablation (SICTRA) System is an alternative source of energy used to ablate AF. The aim of this study was to evaluate the effectiveness of the SICTRA for the treatment of permanent AF in patients with rheumatic mitral valve (MV) disease.
Between February 2002 and April 2003, 70 patients with permanent AF and rheumatic MV disease were randomly assigned to undergo a modified Maze III procedure using SICTRA associated with MV surgery (group A) or MV surgery alone (group B). Groups A and B were similar in terms of baseline characteristics. The in-hospital mortality rate was 2.3% (1 death) in group A versus 0% (no deaths) in group B (P>0.99). The additional time required for the left-sided radiofrequency ablation in group A was 14.2+/-5.1 minutes and for right-sided ablation was 12.3+/-4.2 minutes. The mean postoperative follow-up periods were 13.8+/-3.4 and 11.5+/-7.3 months, respectively, in groups A and B. The overall mid-term survival rate was 95.1% in group A and 92.8% in group B (P>0.99). The cumulative rates of sinus rhythm were 79.4% in group A and 26.9% in group B (P=0.001). Doppler echocardiography documented biatrial transport function in 90.3% of group A patients in sinus rhythm.
The SICTRA is effective for treating permanent AF associated with rheumatic MV disease.
Available from: Petr Budera
- "Only a few randomized studies have been published to date and they suffered from relatively
small sample sizes, involving various groupings of patients and with inconsistent published
data relative to mid- and long-term results.8–16 These studies
enrolled only patients scheduled for mitral valve surgery—thus, the efficacy of
surgical ablation in patients undergoing other types of surgery, e.g. "
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ABSTRACT: AimsSurgical ablation procedure can restore sinus rhythm (SR) in patients with atrial fibrillation (AF) undergoing cardiac surgery. However, it is not known whether it has any impact on long-term clinical outcomes.Methods and resultsThis multicentre study randomized 224 patients with AF scheduled for valve and/or coronary surgery: group A (left atrial surgical ablation, n = 117) vs. group B (no ablation, n = 107). The primary efficacy outcome was the SR presence (without any AF episode) during a 24 h electrocardiogram (ECG) after 1 year. The primary safety outcome was the combined endpoint of death/myocardial infarction/stroke/renal failure at 30 days. A Holter-ECG after 1 year revealed SR in 60.2% of group A patients vs. 35.5% in group B (P = 0.002). The combined safety endpoint at 30 days occurred in 10.3% (group A) vs. 14.7% (group B, P = 0.411). All-cause 1-year mortality was 16.2% (A) vs. 17.4% (B, P = 0.800). Stroke occurred in 2.7% (A) vs. 4.3% (B) patients (P = 0.319). No difference (A vs. B) in SR was found among patients with paroxysmal (61.9 vs. 58.3%) or persistent (72 vs. 50%) AF, but ablation significantly increased SR prevalence in patients with longstanding persistent AF (53.2 vs. 13.9%, P < 0.001).Conclusion
Surgical ablation improves the likelihood of SR presence post-operatively without increasing peri-operative complications. However, the higher prevalence of SR did not translate to improved clinical outcomes at 1 year. Further follow-ups (e.g. 5-year) are warranted to show any potential clinical benefit which might occur later.
Available from: Julius Liobikas
- "This treatment method is reasoned as myocardial heating and is easily achievable by transcatheter radiofrequency energy delivery. Furthermore, it has been demonstrated to be an effective and technically simple means of making the focal myocardial thermal injury (Cosman E.R. 1988, Nakagawa H. 1995, Nakagawa H.1998). Since the cardiac conduction paths and other anatomical structures are of a complex morphology, the distances between them are small and vary a dozen or a few millimeters within the limits (Jongbloed M.R.M. 2010, Güden M. 2002, Filho C.A., 2005). Consequently, it is important to know the size and the severity of the violations that will be caused by myocardial destruction of controlled thermal treatment ( "
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ABSTRACT: During the last decades, one of the most common nondrug therapies used for patients cardiac arrhythmia treatment is a controlled thermal destruction of certain myocardial structures and tissues. However, the investigations of small microstructural changes of thermal tissue destruction are neglected. This study investigated the effect of radiofrequency ablation with active electrode cooling, on dog thigh muscle damage character and size. Three experiment sessions were performed on thirteen mongrel dogs. The first radiofrequency ablation session was done without cooling. In the second session the electrode was cooled with a 0.1% NaCl solution and during the third session, cooling was made with a 0.9% NaCl solution. In all cases the duration of ablation was 30 s and the power was 40 W. Lastly, the calculations of a theoretical model were accomplished. Our experimental results show that the strongest impact of the ablation on tissue damage was observed in the first session, medium in the second session and the lowest in the third session. The average damaged area of ablated tissue was the largest in the first session, medium in the third session and the smallest in the second session (p<0.05). The highest temperature on the surface of the heated tissues at the ablating electrode contact site during the ablation procedure was measured in the first session, medium in the second session and smallest in the third session. Experimental results and theoretical calculations allow making an assumption that the different concentrations of cooling solution influence the ablating tissue damage size and character, due to the redistribution of electric field strength lines. The examination of histological preparations revealed that in the tissues affected by the ablation procedure the enclosed "ring" shape stripe of damaged area is detectable.
Available from: Philippe Chevalier
- "Interestingly, the average efficacy of 50% correlates with the left atrial catheter ablation in patients with heart failure and chronic AF . By comparison, Cox-Maze III RFA has been evaluated in one randomized study involving 70 patients with permanent AF . The efficacy of this extensive ablation lesion set that yields a 79% freedom from arrhythmias is in accord with the critical mass hypothesis . "
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ABSTRACT: Randomized studies evaluating left atrial radiofrequency ablation (RFA) in patients with persistent atrial fibrillation undergoing mitral valve surgery are scarce and monocentric.
To evaluate the efficacy of left atrial RFA concomitant with mitral valve surgery to restore and maintain sinus rhythm.
The SAFIR is a multicentre, double-blinded, centrally randomized study involving four university hospitals. Between December 2002 and September 2005, 43 patients with mitral valve disease and long-standing, persistent atrial fibrillation (duration>6 months) were included. We compared valvular surgery alone (n=22) or with left atrial RFA (n=21). The main endpoint was sinus rhythm at 12 months without recurrence of arrhythmia during follow-up. Secondary endpoints were surgical adverse events, atrial fibrillation relapses, stroke and echocardiographic measurements after three and 12 months' follow-up. Analyses of the efficacy criteria were performed on an intention-to-treat basis.
The primary endpoint occurred significantly more often in the RFA group than in the control group (respectively, 12/21 patients [57%] vs 1/22 patients [4%]; p=0.004). There were more patients with sinus rhythm in the RFA group than in the control group at discharge (72.7% vs 4.8%; p<0.005), 3-month follow-up (85.7% vs 23.8%; p<0.01) and 12-month follow-up (95.2% vs 33.3%; p<0.005). The patients in the RFA group had similar rates of postoperative complications and stroke during follow-up as those in the control group.
This multicentre study suggests that left atrial RFA is effective and safe in patients with chronic atrial fibrillation and mitral valve disease.
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