Zbyněk Straka

Comparison of cardiac surgery with left atrial surgical ablation vs. cardiac surgery without atrial ablation in patients with coronary and/or valvular heart disease plus atrial fibrillation: final results of the PRAGUE-12 randomized multicentre study †

Aims Surgical 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 results This 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.

Treatment of stand-alone atrial fibrillation with a right thoracoscopic approach employing a microwave or monopolar radiofrequency energy source: long-term results

OBJECTIVES Minimally invasive surgery for atrial fibrillation (AF) has rapidly evolved recently. The long-term efficacy of most of these procedures is poorly known. METHODS Between 2006 and 2010, 38 drug-resistant, symptomatic patients with stand-alone AF underwent unilateral, thoracoscopic, off-pump ablation. The mean age was 60 ± 8.2 (range 42-75) years and the mean AF duration was 46 ± 62 (range 3-240) months. Sixteen patients (42%) had paroxysmal, 9 (24%) had persistent and 13 (34%) had long-standing persistent AF. A box lesion was created using a microwave (26 patients) or monopolar radiofrequency (12 patients) system. Patients were prospectively followed with repeat electrocardiograms (ECGs) and ECG Holters. Additional catheter ablation was offered to patients with recurrence of arrhythmia. RESULTS All procedures were completed as planned with one conversion to sternotomy, zero mortality and minimal in-hospital complications. The mean follow-up duration was 70 ± 19 (range 20-88) months. Arrhythmia-free survival rates after the procedure were 50, 44.4, 24.1 and 10.8% at 6, 12, 36 and 60 months, respectively, with most recurrences in the first 6 months. Twelve patients underwent additional catheter ablation(s); from the last intervention, 75% of them were in sinus rhythm (SR) with a mean follow-up of 31 ± 23 (range 4-86) months. Overall, at the end of follow-up, only 3 patients were still in SR without any arrhythmia recurrence. Major complications (cerebral, peripheral embolism or bleeding) occurred in 5 patients. CONCLUSIONS Unilateral, thoracoscopic AF ablation is safe and technically feasible. However, the results of the microwave and monopolar radiofrequency devices were less than satisfactory, with a gradual decline in arrhythmia-free survival over a very long-term follow-up.

Design and Rationale of the PRAGUE-12 Trial: A Large, Prospective, Randomized, Multicenter Trial That Compares Cardiac Surgery With Left Atrial Surgical Ablation With Cardiac Surgery Without Ablation in Patients With Coronary and/or Valvular Heart Disease Plus Atrial Fibrillation

Surgical 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 clinical outcomes. There is a need for a randomized trial with long‐term follow‐up to study the outcome of surgical ablation in patients with coronary and/or valve disease and AF. Patients are prospectively enrolled and randomized either to group A (cardiac surgery with left atrial ablation) or group B (cardiac surgery alone). The primary efficacy outcome is the SR presence (without any AF episode) during a 24‐hour electrocardiogram after 1 year. The primary safety outcome is the combined end point of death, myocardial infarction, stroke, and renal failure at 30 days. Long‐term outcomes are a composite of total mortality, stroke, bleeding, and heart failure at 1 and 5 years. We finished the enrollment with a total of 224 patients from 3 centers in 2 countries in December 2011. Currently, the incomplete 1‐year data are available, and the patients who enrolled first will have their 5‐year visits shortly. PRAGUE‐12 is the largest study to be conducted so far comparing cardiac surgery with surgical ablation of AF to cardiac surgery without ablation in an unselected population of patients who are operated on for coronary and/or valve disease. Its long‐term results will lead to a better recognition of ablations potential clinical benefits.

Values of osteoprotegerin in aortic valve tissue in patients with significant aortic stenosis depend on the existence of concomitant coronary artery disease

INTRODUCTION Calcific aortic valve stenosis (CAVS) is a serious clinical problem. The strongest predictor of CAVS progression is the amount of calcium in the aortic valve. The pathogenesis of CAVS is largely consistent with the pathogenesis of atherosclerosis; however, about 50% of patients with CAVS do not exhibit significant atherosclerosis. Cardiovascular calcification is currently considered an actively regulated process, in which the important role is attributed to the RANKL/RANK/OPG (receptor activator of nuclear factor κB ligand/RANK/osteoprotegerin) axis. We measured OPG levels in the tissue of calcified, stenotic aortic valves in relation to the presence or absence of coronary artery disease (CAD). MATERIALS AND METHODS Aortic valve samples were collected from 105 patients with calcified, mainly severe aortic stenosis, who were divided into two groups according to the presence of CAD. In Group A (n=44), there were normal coronary artery findings, while in Group B (n=61), there was angiographically demonstrated >50% stenosis of at least one coronary artery. The control Group C (n=21) consisted of patients without aortic stenosis and with normal angiographic findings on coronary arteries. RESULTS The highest tissue concentrations of OPG [median (pmol/L), 25th-75th percentile] were found in Group A [6.95, 3.96-18.37], which was significantly different compared to the other two groups (P=.026 and .001, respectively). The levels of OPG in Group B [4.15, 2.47-9.16] and in Group C [2.25, 1.01-5.08] did not differ significantly (P=.078); however, the lowest concentrations of OPG were found in Group C. Neither age nor gender in our study had effect on tissue levels of OPG (P=.994 for gender; P=.848 for age). CONCLUSION Calcified and narrowed aortic valves, compared to the normal valves, were accompanied by a change in tissue concentrations of OPG, which is, in addition, dependent on the presence or absence of CAD. The highest tissue concentrations of OPG in our work were found in patients with significant aortic stenosis without concomitant CAD.

Prognostic impact and change of concomitant mitral regurgitation after surgical or transcatheter aortic valve replacement for aortic stenosis.

BACKGROUND Significant aortic stenosis (AS) is frequently associated with mitral regurgitation (MR) of varying degrees. We sought to assess the change in MR grade after the aortic valve procedure, to find predictors of MR improvement and finally to determine the prognostic impact of persistent MR. METHODS We retrospectively analyzed a group of 101 AS patients who underwent aortic valve replacement (AVR) or transcatheter aortic valve implantation (TAVI) at our institution between January 2007 and March 2014 and who presented with MR grade 2 or higher on preoperative echocardiogram - 35 patients underwent an isolated AVR, 18 underwent TAVI, and the rest underwent a combined procedure, which included coronary artery bypass grafting. The mean follow-up was 28.5±21 months. RESULTS MR improved significantly after the procedures (2.4±0.5 vs. 1.9±0.9, p<0.001) and a decline in the severity of MR was observed regardless of etiology (degenerative/post-rheumatic, functional/ischemic, combined) without significant changes between groups (p=0.667). Downgrading of MR severity was associated with improvement in ejection fraction (p=0.021) and reduction in the size of cardiac chambers, especially the left atrium (left atrial diameter, p<0.001). None of the preoperatively evaluated factors (severity of AS, MR etiology, ejection fraction, cardiac chamber dimensions, coronary artery disease, and New York Heart Association functional class) was a significant predictor of MR improvement. Persistence of higher degrees of MR was associated with a more frequent need for cardiovascular hospitalization, while the survival rate 3 years after procedure was not affected (p=0.146). CONCLUSIONS In the majority of AS patients, an aortic valve procedure leads to reduction in coexistent MR. A significant decrease in the severity of MR in our study was observed regardless of etiology and preoperative grade of MR. Persistence of higher degrees of MR was associated with increased patient morbidity.