Obesity and postoperative atrial fibrillation in patients undergoing cardiac surgery : systematic review and meta-analysis

Introduction: Post-operative atrial fibrillation (POAF) is one of the most common complications following cardiac surgery. However, it is unclear whether there is a relationship between obesity and POAF. We thus assessed all available evidence investigating the association between obesity and POAF, also considering any link between POAF and other post-operative conditions such as mortality, stroke, myocardial infarctions and respiratory complications. Methods: Five electronic databases were searched and relevant studies were identified. Data was extracted and meta-analyzed from the identified studies. Results: We found that obese patients had significantly higher odds of POAF when compared with non-obese patients (P=0.006). There was also significant heterogeneity among the identified studies. POAF when compared with no-POAF was associated with an increased risk of stroke (P<0.0001), 30-day mortality (P=0.005) and respiratory complications (P<0.00001). However, we found no significant link between POAF and myocardial infarctions (P=0.79). Conclusions: Our findings suggest that obesity is associated with a moderately higher risk of POAF. While POAF is also associated with an increased incidence of stroke, 30-day mortality and respiratory complications, further studies must be conducted before conclusions can be made about the long-term outcomes.9 page(s

Bioprosthetic versus mechanical prostheses for valve replacement in end-stage renal disease patients : systematic review and meta-analysis

Background: Patients with end-stage renal disease (ESRD) indicated for dialysis are increasingly requiring cardiac valve surgery. The choice of bioprosthetic or mechanic valve prosthesis for such patients requires careful risk assessment. A systematic review and meta-analysis was performed to assess current evidence available. Methods: A comprehensive search from six electronic databases was performed from their inception to February 2015. Results from patients with ESRD undergoing cardiac surgery for bioprosthetic or mechanical valve replacement were identified. Results: Sixteen studies with 8,483 patients with ESRD undergoing cardiac valve replacement surgery were included. No evidence of publication bias was detected. Prior angioplasty by percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) surgery was significantly higher in the bioprosthetic group compared to the mechanical group (16.0% vs. 12.0%, P=0.04); all other preoperative baseline patient characteristics were similar. There was no significant difference in 30-day mortality or all-cause mortality between the two comparisons. Compared with the mechanical group, the frequency of bleeding (5.2% vs. 6.4%, P=0.04) and risk of thromboembolism (2.7% vs. 12.8%, P=0.02) were significantly lower in the bioprosthetic group. There were similar rates of reoperation and valve endocarditis. Conclusions: The present study demonstrated that patients with ESRD undergoing bioprosthetic or mechanical valve replacement had similar mid-long term survival. The bioprosthetic group had lower rates of bleeding and thromboembolism. Further studies are required to differentiate the impact of valve location. The presented results may be applicable for ESRD patients requiring prosthetic valve replacement.9 page(s

Effectiveness and safety of simultaneous hybrid thoracoscopic endocardial catheter ablation of atrial fibrillation in obese and non-obese patients

Background: We evaluated the safety and effectiveness of the hybrid thoracoscopic endocardial epicardial ablation technique for the treatment of atrial fibrillation (AF) in obese versus non-obese patients.Methods: Between January 2010 and January 2015, a cohort of 61 patients were retrospectively identified to undergo ablation of AF as a stand-alone procedure using a thoracoscopic, hybrid epicardial-endocardial technique. All patients underwent continuous 7-day Holter monitoring at 3, 6 months, 1 year and yearly thereafter.Results: A total of 40% of the obese cohort had persistent or long-standing AF, compared to 54.9% of the non-obese cohort. There were no deaths or conversion to cardiopulmonary bypass required. At 3-year follow-up, 60% of the obese group were in sinus rhythm (SR) with no episode of AF, atrial flutter or atrial tachycardia lasting 30 s off anti-arrhythmic drugs. This was compared to 70.6% in the non-obese group, with no significant difference between the groups (P= 0.468). For success rates on anti-arrhythmic drugs, this was 80% in the obese group compared to 86% in the non-obese group at 3-year follow-up (P= 0.637). No patient died and no thromboembolic/bleeding events or procedure-related complications occurred during the follow-up.Conclusions: In a retrospective cohort with approximately half with persistent or long-standing AF, thoracoscopic hybrid epicardial endocardial ablation proved to be equally effective and safe in obese versus non-obese patients. Current preliminary findings require further validation in multi-institutional prospective studies with larger sample sizes.</p