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Background: Atrial fibrillation (AF) has a substantial genetic basis. Identification of individuals at greatest AF risk could minimize the incidence of cardioembolic stroke., Methods: To determine whether genetic data can stratify risk for development of AF, we examined associations between AF genetic risk scores and incident AF in 5 prospective studies comprising 18 919 individuals of European ancestry. We examined associations between AF genetic risk scores and ischemic stroke in a separate study of 509 ischemic stroke cases (202 cardioembolic [40%]) and 3028 referents. Scores were based on 11 to 719 common variants (≥5%) associated with AF at P values ranging from <1×10 -3 to <1×10 -8 in a prior independent genetic association study., Results: Incident AF occurred in 1032 individuals (5.5%). AF genetic risk scores were associated with new-onset AF after adjustment for clinical risk factors. The pooled hazard ratio for incident AF for the highest versus lowest quartile of genetic risk scores ranged from 1.28 (719 variants; 95% confidence interval, 1.13-1.46; P =1.5×10 -4 ) to 1.67 (25 variants; 95% confidence interval, 1.47-1.90; P =9.3×10 -15 ). Discrimination of combined clinical and genetic risk scores varied across studies and scores (maximum C statistic, 0.629-0.811; maximum ΔC statistic from clinical score alone, 0.009-0.017). AF genetic risk was associated with stroke in age- and sex-adjusted models. For example, individuals in the highest versus lowest quartile of a 127-variant score had a 2.49-fold increased odds of cardioembolic stroke (95% confidence interval, 1.39-4.58; P =2.7×10 -3 ). The effect persisted after the exclusion of individuals (n=70) with known AF (odds ratio, 2.25; 95% confidence interval, 1.20-4.40; P =0.01)., Conclusions: Comprehensive AF genetic risk scores were associated with incident AF beyond associations for clinical AF risk factors but offered small improvements in discrimination. AF genetic risk was also associated with cardioembolic stroke in age- and sex-adjusted analyses. Efforts are warranted to determine whether AF genetic risk may improve identification of subclinical AF or help distinguish between stroke mechanisms., (© 2016 American Heart Association, Inc.)

Aim: The aim of this prospective study was to assess the presence of sinus rhythm and atrial transport function after surgical ablation of atrial fibrillation using cryoenergy, and to evaluate predictors of the success of the procedure., Methods: Between January 2005 and September 2006, 100 consecutive patients underwent left atrial cryoablation as a concomitant surgical procedure (46 patients with paroxysmal or persistent atrial fibrillation and 54 with permanent atrial fibrillation). Mitral valve surgery was performed in 74%. The mean and the median times of follow-up were 20 +/- 8.5, and 24 months respectively. Atrial mechanical function was assessed by echocardiography., Results: Sinus rhythm was achieved during the postoperative follow-up in 71-81% of patients - significantly more often in the group with paroxysmal and persistent atrial fibrillation (90-98%), than patients with permanent atrial fibrillation prior to surgery (51-65%) (p<0.002). At 12 and 24 months after the surgery, a total of 68.2% and 51.2% of the patients were free from atrial fibrillation; 73.9% and 60.7% of the patients from the paroxysmal and persistent atrial fibrillation group, and 60.3% and 37.7% of patients with permanent atrial fibrillation (p=0.05). Five per cent of patients required postoperative permanent pacemaker implantation. An effective left and right atrial mechanical function was detected in 70-90%, and 96-98% of patients with sinus rhythm respectively. The following circumstances were identified as negative predictors of the presence of sinus rhythm after the ablation procedure: growing diameter of the left atrium, the duration of atrial fibrillation and the severity of mitral and tricuspid regurgitation before surgery (p<0.05). Restoration of the left atrial transport function was negatively predicted by the preoperative diameter of the left atrium, the presence of mitral valve stenosis and the severity of tricuspid regurgitation (p<0.05). A total of 95.4% of patients were free from stroke at one-year follow-up, and 94.1% at 2 years after surgery., Conclusion: Stable sinus rhythm and effective left atrial transport function are the main factors resulting in decreased morbidity after successful ablation of atrial fibrillation. A careful post-operative follow-up of the patients and individualised treatment are necessary.

Background: Atrial fibrillation is the most frequent sustained arrhythmia. It is associated with higher morbidity and mortality of patients. Cryoablation was introduced to the current practise in cardiac surgery as a non-pharmacological method of therapy of atrial fibrillation. The aim of the study was to assess the effect of surgical ablation of atrial fibrillation on the attainment and maintenance of sinus rhythm in patients undergoing concomitant cardiac surgery., Methods and Results: Ninety four consecutive patients with atrial fibrillation (paroxysmal, persistent or permanent) were followed up prospectivelly. The mean age was 67.8 years; there were 39 (41.5%) women in the study group. Forty two patients (44.7%) had paroxysmal or persistent atrial fibrillation and 52 (55.3%) of them had permanent atrial fibrillation before surgery. Patients with permanent atrial fibrillation had significantly bigger preoperative left atrial diameter (51.2 versus 46.6 mm) and more severe tricuspid regurgitation (grade 2.3/4 versus grade 1.4/4) compared to the group with paroxysmal and persistent atrial fibrillation. Mitral valve surgery was significantly more frequent in patients with permanent atrial fibrillation too. Operations were performed between January 2005 and July 2006 using flexible argon-based cryoablative device. Sinus rhythm was achieved statistically significantly more frequently in patients with preoperative paroxysmal and persistent atrial fibrillation in comparison with patients with permanent atrial fibrillation--at discharge, 1, 3.5 and 6 months after operation (90.5-96.3 % versus 50-65.9%). At 12 months it was only statistical trend (84.6% versus 63.3%). Kaplan-Meier analysis demonstrated a 79.4% freedom from atrial fibrillation at 12 months. Preoperative atrial size and duration of atrial fibrillation were the most significant negative predictors of maintenance of sinus rhythm. Four patients (9.3%) required postoperative permanent pacemaker placement. Ischemic stroke occured in 5 (5.3%) patients. Thirty-day motality was 12.9% (12 patients)., Conclusions: Perioperative ablation of atrial fibrillation using cryoenergy is effective therapeutic method for restoring and maintenance of sinus rhythm in relatively high proportion of patients. The most significant predictors of late recurrence are preoperative atrial size and duration of atrial fibrillation. This non-pharmacological method should be routinely used in patients undergoing concomitant cardiac surgery.

Background: Surgical ablation is one of the most effective techniques for treatment of atrial fibrillation. Stable sinus rhythm is achieved and effective atrial contractions are restored in the majority of patients. The aim of the prospective study is to assess the presence of atrial transport function after surgical ablation of atrial fibrillation using cryoenergy and to evaluate predictors of the procedural success., Methods and Results: Between January 2005 and September 2006, 100 consecutive patients underwent left atrium cryoablation as a concomitant cardiac procedure. Their mean age was 67.6 years (range 50 to 82 years), there were 41 (41 %) women. Forty six patients (46 %) suffered from paroxysmal or persistent atrial fibrillation and 54 (54 %) of them from permanent atrial fibrillation before surgery. Atrial mechanical function was assessed by echocardiography (pulsed Doppler examination of the mitral and tricuspidal inflow, presence of the atrial filling [A] wave) after 3.5, 6, 12 and 18 months postoperatively. 79.6 % of patients, who have had sinus rhythm at 3.5 months, were free from atrial fibrillation at 18 months after surgery. The effective left atrial contractions were present at 3.5, 6, 12 and 18 months postoperatively in 70.2 %, 71.9 %, 81.4 % and 73.5 % of patients and we found right atrial transport function in 97 %, 95.3 %, 97.7 % and 97.1 % of patients. There was no significant difference between group with paroxysmal or persistent atrial fibrillation and permanent fibrillation. Negative predictors for restoration of the left atrial transport function were: preoperative mitral stenosis (at 3.5 and 6 months, p=0.02 and p=0.03 respectively), bigger left atrial dimension prior to procedure (only at 3.5 months, p=0.01) and severity of tricuspid regurgitation before surgery (only at 18 months, p=0.01). An ischaemic stroke occured in 7 %. Thirty-day motality was 12 % (12 patients)., Conclusions: Left atrial mechanical funtion was detected in 70-80 % of patients and right atrial function in 95-98 % of patients with sinus rhythm during follow-up of 18 months. Preoperative left atrial dimension, presence of mitral stenosis and severity of tricuspid regurgitation were the most significant predictors for postoperative restoration of the left atrial transport function. Significant reduction in occurence of ischaemic stroke by surgical ablation was not achieved.