In a randomized trial, 4811 patients with atrial fibrillation were assigned to undergo or not undergo left atrial appendage occlusion during cardiac surgery for another indication. At 3 years, 77% of ...the patients continued to receive oral anticoagulation. At 3.8 years, the risk of ischemic stroke or systemic embolism was significantly lower with occlusion than without it.
Impaired myocardial bioenergetics is a hallmark of many cardiac diseases. There is a need of a simple and reproducible method of assessment of mitochondrial function from small human myocardial ...tissue samples. In this study we adopted high-resolution respirometry to homogenates of fresh human cardiac muscle and compare it with isolated mitochondria. We used atria resected during cardiac surgery (n = 18) and atria and left ventricles from brain-dead organ donors (n = 12). The protocol we developed consisting of two-step homogenization and exposure of 2.5% homogenate in a respirometer to sequential addition of 2.5 mM malate, 15 mM glutamate, 2.5 mM ADP, 10 μM cytochrome c, 10 mM succinate, 2.5 μM oligomycin, 1.5 μM FCCP, 3.5 μM rotenone, 4 μM antimycin and 1 mM KCN or 100 mM Sodium Azide. We found a linear dependency of oxygen consumption on oxygen concentration. This technique requires < 20 mg of myocardium and the preparation of the sample takes <20 min. Mitochondria in the homogenate, as compared to subsarcolemmal and interfibrillar isolated mitochondria, have comparable or better preserved integrity of outer mitochondrial membrane (increase of respiration after addition of cytochrome c is up to 11.7±1.8% vs. 15.7±3.1%, p˂0.05 and 11.7±3.5%, p = 0.99, resp.) and better efficiency of oxidative phosphorylation (Respiratory Control Ratio = 3.65±0.5 vs. 3.04±0.27, p˂0.01 and 2.65±0.17, p˂0.0001, resp.). Results are reproducible with coefficient of variation between two duplicate measurements ≤8% for all indices. We found that whereas atrial myocardium contains less mitochondria than the ventricle, atrial bioenergetic profiles are comparable to left ventricle. In conclusion, high resolution respirometry has been adapted to homogenates of human cardiac muscle and shown to be reliable and reproducible.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background
Hybrid ablation (i.e., a combination of a thoracoscopic surgical ablation followed by a catheter ablation) is a treatment option for patients with non-paroxysmal atrial fibrillation (AF). ...Despite its promising efficacy, it is a surgical procedure with a relatively high risk of complications that could affect the quality of life (QoL) of patients, even when sinus rhythm is restored.
Objective
To describe changes in the QoL of patients with non-paroxysmal AF before and after a hybrid ablation.
Methods
Patients after hybrid ablation for persistent or long-standing persistent AF were prospectively studied. Follow-up visits were scheduled at 1, 3, 6, 9, and 12 months. The maintenance of SR was assessed using 1-week Holter recordings at 6 and 12 months and 24-h Holter recordings at 3 and 9 months, or via an implantable loop recorder. QoL was assessed using the Atrial Fibrillation Effect on Quality-of-life (AFEQT) and the EuroQoL-5Dimensions (EQ-5D) questionnaires before and 12 months after ablation.
Results
Seventy-five patients (49 men, age 62.9 ± 8.45 years, 48 (64%) with long-standing persistent AF) were enrolled. Fifty-two (69.3%, SR group) were AF-free during the 12-month follow-up, 16 (21.3%, PAROX group) had only paroxysms of AF after ablation, and 7 (9.3%, PERM group) were on rate control due to permanent AF reoccurrence. The AFEQT score increased significantly in the SR group from 59.9 ± 19.4 to 91.4 ± 10.8 (
p
< 0.001), and in the PAROX group from 58.8 ± 19.0 to 81.5 ± 14.1 (
p
= 0.002) but remained unchanged in the PERM group (44.6 ± 7.5 vs. 47.4 ± 5.5,
p
= 0.24). The EQ-5D score significantly decreased in the descriptive part (from 7.90 ± 2.61 to 6.64 ± 1.90,
p
= 0.0001) and increased on the visual analog scale (from 63.56 ± 19.11 to 79.30 ± 16.9,
p
< 0.0001) in the SR group. In the PAROX group, no significant change was present on either the descriptive part (
p
= 0.3) or in the visual analog scale (
p
= 0.48). Similarly, no significant changes were present on either the descriptive part (
p
= 0.93) or the visual analog scale (
p
= 0.4) in the PERM group.
Conclusion
The QoL of patients with non-paroxysmal AF and patients with AF paroxysms, after successful hybrid ablation, improved significantly in patients with SR. No significant improvement was present in patients on rate control after an unsuccessful ablation.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Hybrid ablation (a combination of thoracoscopic epicardial ablation and catheter ablation) has become a new technique for atrial fibrillation treatment.
The goal of this study was to evaluate the ...success and electrophysiological follow-up after using the COBRA Fusion device to deliver a circumferential lesion set anterior to the pulmonary veins in an attempt to isolate the posterior left atrium (box isolation).
Surgical ablation was carried out via a thoracoscopic approach using the COBRA Fusion radiofrequency catheter. An electrophysiology study was done 2-3 months later to verify box isolation (and to complete it, if needed) and to perform right-sided isthmus ablation. Fat thickness along the presumed box lesion line was measured using preprocedural computed tomography.
Thirty patients (mean age 60.0 ± 11.6 years; 22 men; 8 with long-standing persistent AF and 22 with persistent atrial fibrillation) were enrolled. The duration of the EP study was 216.3 ± 64.2 minutes. Box isolation, based on the EP study, was complete in 12 patients (40%) and incomplete in 18 patients (60%). Successful box isolation was achieved with catheter ablation in 16 of 18 patients (89%). A total of 39 gaps in these 16 patients were identified. Typical gap locations were the anterior-superior part of the superior pulmonary veins and the roofline. Fat thickness along the roofline was substantially higher than that along the inferior line (4.58 ± 1.61 mm vs 2.37 ± 0.76 mm; P < .001).
There is a relatively low rate of complete isolation using the COBRA catheter ablation system. The superior line and anterior parts of superior pulmonary veins have most conduction gaps.
Abstract Objectives Current recommendations support surgical treatment of atrial fibrillation (AF) in patients indicated for cardiac surgery. These procedures are referred to as concomitant and may ...be carried out using radiofrequency energy or cryo-ablation. This study aimed to assess the electrophysiological findings in patients undergoing concomitant cryo-ablation. Methods Patients with non-paroxysmal AF undergoing coronary artery bypass grafting and/or valve repair/replacement were included in the trial if concomitant cryo-ablation was part of the treatment plan according to current guidelines. The patients reported in this study were assigned to undergo staged percutaneous radiofrequency catheter ablation (PRFCA), i.e., hybrid treatment, as a part of the SURHYB trial protocol. Results We analyzed 103 patients who underwent PRFCA 105 ± 35 days after surgery. Left and right pulmonary veins (PVs) were found isolated in 65 (63.1%) and 63 (61.2%) patients, respectively. The LA posterior wall isolation and mitral isthmus conduction block were found in 38 (36.9%) and 18 (20.0%) patients, respectively. Electrical reconnections (gaps) in the left PVs were more often localized superiorly than inferiorly (57.9% vs. 26.3%, P = 0.005) and anteriorly than posteriorly (65.8% vs. 31.6%, P = 0.003). Gaps in the right PVs were more equally distributed anteroposteriorly but dominated in superior segments (72.5% vs. 40.0%, P = 0.003). There was a higher number of gaps on the roof line compared to the inferior line (131 (67.2%) vs. 67 (42.2%), P < 0.001). Compared to epicardial cryo-ablation, endocardial was more effective in creating PVs and LA posterior wall isolation ( P < 0.05). Cryo-ablation using nitrous oxide (N 2 0) or argon (Ar) gas as cooling agents was similarly effective ( P = NS). Conclusions The effectiveness of surgical cryo-ablation in achieving transmural and durable lesions in the left atrium is surprisingly low. Gaps are located predominantly in the superior and anterior portions of the PVs and on the roof line. Endocardial cryo-ablation is more effective than epicardial ablation, irrespective of the cooling agent used.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Abstract 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.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Post-operative atrial fibrillation (PoAF) occurs in ~ 30% of patients after cardiac surgery. The etiology of PoAF is complex, but a disbalance in autonomic systems plays an important role. The goal ...of this study was to assess whether pre-operative heart rate variability analysis can predict the risk of PoAF.
Patients without a history of AF with an indication for cardiac surgery were included. Two-hour ECG recordings one day before surgery was used for the HRV analysis. Univariate and multivariate logistic regression, including all HRV parameters, their combination, and clinical variables, were calculated to find the best predictive model for post-operative AF.
One hundred and thirty-seven patients (33 women) were enrolled in the study. PoAF occurred in 48 patients (35%, AF group); the remaining 89 patients were in the NoAF group. AF patients were significantly older (69.1 ± 8.6 vs. 63.4 ± 10.5 yrs., p = 0.002), and had higher CHA
DS
-VASc score (3 ± 1.4 vs. 2.5 ± 1.3, p = 0.01). In the multivariate regression model, parameters independently associated with higher risk of AF were pNN50, TINN, absolute power VLF, LF and HF, total power, SD2, and the Porta index. A combination of clinical variables with HRV parameters in the ROC analysis achieved an AUC of 0.86, a sensitivity of 0.95, and a specificity of 0.57 and was more effective in PoAF prediction than a combination of clinical variables alone.
A combination of several HRV parameters is helpful in predicting the risk of PoAF. Attenuation of heart rate variability increases the risk for PoAF.
Background Catheter and surgical ablation of atrial fibrillation (AF) can be associated with a risk of thromboembolic events. The goal of this study was to assess optimal anticoagulation management ...during thoracoscopic ablation of AF. Methods Fifty-two patients with persistent or long-standing persistent AF underwent hybrid ablation consisting of thoracoscopic ablation followed by electrophysiologic (EP) evaluation and consecutive ablation if indicated. The thoracoscopic ablation was performed using three different anticoagulation protocols: (1) without periprocedural heparin and without occlusion of the left atrial appendage; (2) with periprocedural heparin but without left atrial appendage occlusion; and (3) with periprocedural heparin and left atrial appendage occlusion. Transesophageal echocardiography (TEE) was obligatorily used to screen for intraatrial thrombi before the surgical and EP procedure and before hospital discharge for patients in protocols 2 and 3. Results In group 1 (n = 20), 1 patient (5%) had a postoperative stroke with persistent neurologic deficit, and 6 other patients (30%) had a new thrombus in the left atrial appendage seen on the pre-EP TEE. In group 2 (n = 6), 3 left atrial appendage thrombi occurred (50%; 2 on predischarge TEE and 1 on pre-EP TEE). In group 3 (n = 26), no intracardiac thrombi were found on predischarge and pre-EP TEE, and there were no strokes in this group of patients, namely, the rates of thrombus or stroke were significantly reduced when compared with groups 1 and 2 ( p = 0.001). Conclusions Thoracoscopic ablation of AF can be associated with a risk of left atrial appendage thrombus formation and possibly also stroke. With administration of heparin during the ablation, followed by occlusion of the left atrial appendage as a part of the procedure, this risk can be effectively reduced.
Off-pump coronary artery bypass graft surgery (OPCAB) is an established alternative to on-pump surgical revascularization. Previous studies in patients with low or intermediate risk showed no ...significant differences between off-pump and on-pump surgical revascularization. The aim of this study was to compare the two techniques in patients with high operative risk.
PRAGUE-6 is a prospective randomized single-center study of 206 patients, with an additive EuroSCORE ≥ 6, scheduled for isolated coronary surgery: Group A - on-pump (n = 108) versus Group B - off-pump (n = 98). The primary outcome was a combined endpoint of all-cause deaths, stroke, myocardial infarction, or renal failure requiring new hemodialysis, within 30 days and 1 year after randomization. All data were analyzed using the "intention-to-treat" principle.
Early postoperative myocardial infarction was detected in 12.1% (A) vs. 4.1% (B) of patients (P = 0.048, hazard ratio 0.32, 95% CI 0.11-0.99). There was a significantly higher incidence of primary combined end-point in group A (20.6% vs. 9.2%, P = 0.028, HR 0.41, 95% CI 0.19-0.91) in the first 30 days, but not after 1 year (30.8% vs. 21.4%, P = 0.117, HR 0.65, CI 0.37-1.12).
Off-pump surgical revascularization in patients with high operative risks can significantly reduce the incidence of major postoperative complications during the first 30 days. There was no statistically significant difference in the incidence of these complications after 1 year.
A case of macro-reentrant tachycardia associated with a box lesion after thoracoscopis left atrial surgical atrial fibrillation (AF) ablation yet to be described. The goal was to clarify the ...mechanisms and electrophysiological characteristics of this type of tachycardia.
A patient was admitted for an EP study following surgical thoracoscopic AF ablation (box lexion formation by right-sided Cobra thoracoscopic ablation). Thoracoscopic ablation was done as the first step of the hybrid ablation approach to the persistent AF; the second step was the EP study. At the EP study, he presented with incessant regular tachycardia (cycle length of 226 ms). An EP study with conventional, 3D activation and entrainment mapping was done to assess the tachycardia mechanism. Two conduction gaps in the superior line (roofline) between the superior pulmonary veins were discovered. The tachycardia was successfully treated with a radiofrequency application near the gap close to the left superior pulmonary vein; however, following tachycardia termination, pulmonary vein isolation was absent. A second radiofrequency application, close to the roof of the right superior pulmonary, vein closed the gap in the box and led to the isolation of all 4 pulmonary veins. No atrial tachycardia recurred during the 6-month follow-up.
Conduction gaps in box lesion created by thoracospcopic ablation can present as a novel type of man-made tachycardia after surgical ablation of atrial fibrillation. Activation and entrainment mapping is necessary for an accurate diagnosis.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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