Surgical Ablation of Atrial Fibrillation in High-Risk Patients: Success versus Risk.

BACKGROUND: Surgical atrial ablation is evaluated by surgeons in relation to the estimated surgical risk. We analyze whether high-risk patients (HRPs) experience risk escalation by ablation procedures. METHODS: The CASE-Atrial Fibrillation (AF) registry is a prospective, multicenter, all-comers registry of atrial ablation in cardiac surgery. We analyzed the 1-year outcome regarding survival and rhythm endpoints of 1,000 consecutive patients according to the operative risk classification (EuroSCORE II ≤ 2 vs. >2). RESULTS: Higher NYHA (New York Heart Association) score, ischemic heart failure, status poststroke, renal insufficiency, chronic obstructive pulmonary disease, and diabetes mellitus were strongly represented in HRPs. HRPs exhibit more left ventricular ejection fraction < 40% (19.2 vs. 8.8%; p < 0.001) but identical left atrial diameter and left ventricular end-diastolic diameter compared with low-risk patients (LRPs). CHA2DS-Vasc-score (2.4 ± 1 vs. 3.6 ± 1.5; p < 0.001), sternotomies, combination surgeries, coronary artery bypass graft, and mitral valve procedures were increased in HRPs. LRPs underwent stand-alone ablations as well. Ablation energy did not differ. Left atrial appendage closure was performed in up to 86.1% (mainly cut-and-sew procedures). Mortality corresponded to the original risk class without an escalation that may be related to ablation, stroke rate, or myocardial infarction. A total of 60.6% of HRPs versus 75.1% of LRPs were discharged in sinus rhythm. Long-term EHRA (European Heart Rhythm Association) score symptoms were lower in HRPs. Repeated rhythm therapies were rare. Additional antiarrhythmics received a minority without group dependency. A total of 1.6 versus 4.1% of HRPs (p = 0.042) underwent long-term stroke; excess mortality was not observed. Anticoagulation remained common in HRPs. CONCLUSION: Surgical risk and long-term mortality are determined by the underlying disease. In HRPs, freedom from AF and symptom relief can be achieved. Preoperative risk scores should not lead to withholding an ablation procedure.

Research Opportunities in Stroke Prevention for Atrial Fibrillation: A Report From a National Heart, Lung, and Blood Institute Virtual Workshop.

Atrial fibrillation (AF) is one of the strongest risk factors for ischemic stroke, which is a leading cause of disability and death. Given the aging population, increasing prevalence of AF risk factors, and improved survival in those with cardiovascular disease, the number of individuals affected by AF will continue increasing over time. While multiple proven stroke prevention therapies exist, important questions remain about the optimal approach to stroke prevention at the population and individual patient levels. Our report summarizes the National Heart, Lung, and Blood Institute virtual workshop focused on identifying key research opportunities related to stroke prevention in AF. The workshop reviewed major knowledge gaps and identified targeted research opportunities to advance stroke prevention in AF in the following areas: (1) improving risk stratification tools for stroke and intracranial hemorrhage; (2) addressing challenges with oral anticoagulants; and (3) delineating the optimal roles of percutaneous left atrial appendage occlusion and surgical left atrial appendage closure/excision. This report aims to promote innovative, impactful research that will lead to more personalized, effective use of stroke prevention strategies in people with AF.

The German CArdioSurgEry Atrial Fibrillation Registry: In-Hospital Outcomes.

BACKGROUND: The aim of this study was to describe outcomes of patients undergoing surgical ablation for atrial fibrillation (AF) as either stand-alone or concomitant cardiosurgical procedures in Germany. METHODS: Patients with AF undergoing concomitant or stand-alone surgical ablation were included in the registry. Cardiac surgery centers across Germany were invited to participate and sought to enroll 1,000 consecutive patients. Data was obtained through electronic case report forms. The protocol mandated follow-up interviews at 1 year. RESULTS: Between January 2017 and April 2020, 17 centers enrolled 1,000 consecutive patients. Among concomitant surgical patients (n = 899), paroxysmal AF was reported in 55.4% patients. Epicardial radio frequency (RF) bilateral pulmonary vein isolation (PVI) with excision of the left atrial appendage (LAA) was the most common operative strategy. In the stand-alone cohort (n = 101), persistent AF forms were reported in 84.1% of patients. Moderate-to-severe symptoms were reported in 85.1%. Sixty-seven patients had previously underwent at least two failed catheter ablative procedures. Thoracoscopic epicardial RF bilateral PVI and completion of a "box-lesion" with LAA closure were frequently preformed. Major cardiac and cerebrovascular complications occurred in 38 patients (4.3%) in the concomitant group. No deaths were reported in the stand-alone group. At discharge, sinus rhythm was achieved in 88.1% of stand-alone and 63.4% concomitant patients. CONCLUSION: The CArdioSurgEry Atrial Fibrillation registry provides insights into surgical strategies for AF ablation in a considerable cohort across Germany. This in-hospital data demonstrates that concomitant and stand-alone ablation during cardiac surgery is safe and effective with low complication rates.

The German Cardiosurgery Atrial Fibrillation Registry: 1-Year Follow-up Outcomes.

OBJECTIVES: This study of German Cardiosurgery Atrial Fibrillation (CASE-AF) registry aims to describe the 1-year outcomes of patients undergoing ablative procedures for atrial fibrillation (AF) in a cardiosurgical setting. METHODS: Between January 2017 and April 2020, 17 German cardiosurgical units enrolled 1,000 consecutive patients undergoing concomitant or stand-alone ablation for AF. In-hospital and 1-year follow-up data were collected on web-based electronic case report forms. The protocol mandated telephone-based follow-up contact after 1 year. RESULTS: At 1-year follow-up (median, 14.5 months [12.6-18.2 months]), significant improvement (p < 0.0001) in baseline modified European Heart Rhythm Association Class I was reported in both concomitant and stand-alone patients. Follow-up examinations were completed in 97.9% of cases, and a sinus rhythm was reported in 60.2 and 63.6% of stand-alone and concomitant patients, respectively. Statistically significant factors determining late recurrence were female gender (p = 0.013), preoperative persistent AF (p < 0.0001), and presence of cardiac implantable electronic device (p = 0.011). All-cause mortality at 1 year was 1% (n = 1) in stand-alone patients and 6.7% (n = 58) in concomitant patients. CONCLUSION: Surgical ablation of AF is safe and provides satisfactory results at short-term follow-up, with significant improvement in patient symptoms. Adequate cardiac rhythm monitoring should be prioritized for higher quality data acquisition.

A randomized prospective multicenter trial for stroke prevention by prophylactic surgical closure of the left atrial appendage in patients undergoing bioprosthetic aortic valve surgery--LAA-CLOSURE trial protocol.

Patients undergoing surgical aortic valve replacement (SAVR) are at high risk for atrial fibrillation (AF) and stroke after surgery. There is an unmet clinical need to improve stroke prevention in this patient population. The LAA-CLOSURE trial aims to assess the efficacy and safety of prophylactic surgical closure of the left atrial appendage for stroke and cardiovascular death prevention in patients undergoing bioprosthetic SAVR. This randomized, open-label, prospective multicenter trial will enroll 1,040 patients at 13 European sites. The primary endpoint is a composite of cardiovascular mortality, stroke and systemic embolism at 5 years. Secondary endpoints include cardiovascular mortality, stroke, systemic embolism, bleed fulfilling academic research consortium (BARC) criteria, hospitalization for decompensated heart failure and health economic evaluation. Sample size is based on 30% risk reduction in time to event analysis of primary endpoint. Prespecified reports include 30-day safety analysis focusing on AF occurrence and short-term outcomes and interim analyses at 1 and 3 years for primary and secondary outcomes. Additionally, substudies will be performed on the completeness of the closure using transesophageal echocardiography/cardiac computed tomography and long-term ECG recording at one year after the operation.

Patient selection for LIVE therapy: From clinical indications to multimodality imaging individual case planning.

BACKGROUND: Less Invasive Ventricular Enhancement (LIVE) with Revivent TC is an innovative therapy for symptomatic ischemic heart failure (HF). It is designed to reconstruct a negatively remodeled left ventricle (LV) after an anterior myocardial infarction (MI) by plication of the scar tissue. Its indications are specific, and as with any other structural heart intervention, the success of the procedure starts with appropriate patient selection. We aim to present the indications of the technique, crucial aspects in patient selection, and individual case planning approach. METHODS AND RESULTS: After clinical evaluation, transthoracic echocardiography is the first imaging modality to be performed in a potential candidate for the therapy. However, definitive indication and detailed case planning rely on late gadolinium-enhanced cardiac magnetic resonance imaging or multiphasic contrast-enhanced cardiac computed tomography. These imaging modalities also assist with relative or absolute contra-indications for the procedure. Individual assessment is done to tailor the procedure to the specifics of the LV anatomy and location of the myocardial scar. CONCLUSION: LIVE procedure is a unique intervention to treat symptomatic HF and ischemic cardiomyopathy after anterior MI. It is a highly customizable intervention that allows a patient-tailored approach, based on multimodality imaging assessment and planification.

Device-based prevention of neurological events in coronary artery bypass patients with calcified ascending aorta.

Patients with severely calcified aorta undergoing conventional cardiac surgery are at increased risk for postoperative neurologic deficits. Implementation of cerebroprotective devices may substantially reduce or even eliminate the risk of the adverse neurologic events, thus enabling surgical therapy, especially when interventional treatment cannot be considered an alternative option.

Does Preoperative Sinus Rhythm Influence Surgical Ablation's Perioperative Safety in Patients with Atrial Fibrillation?

BACKGROUND: Despite excellent data on lowering long-term stroke and all-cause mortality rates, currently, only 25-40% of atrial fibrillation (AF) patients undergo simultaneous surgical ablation therapy (SA) during cardiac surgery. Surgeon's fear exposing their patients to an additional, unjustified, and disproportionate risk when performing SA in AF patients presenting with sinus rhythm (SR) before surgery. To clarify the influence of preoperative SR before SA for AF, we conducted a subgroup analysis of the German Cardiosurgical Atrial Fibrillation (CASE-AF) register. METHODS: Between September 2016 and August 2020, 964 AF patients with an underlying cardiac disease were scheduled for surgery with SA and enrolled in the CASE-AF register. Data prospectively were collected and analyzed retrospectively. We divided the entire cohort into an SR-group (38.2%, N = 368) and an AF-group (61.8%, N = 596), based on preoperative heart rhythm. RESULTS: Over half of the patients were moderately affected by their AF, with no difference between the groups (European Heart Rhythm Association class ≥IIb: SR-group 54.2% versus AF-group 58.5%, P = .238). The AF-group had a higher preoperative EuroSCORE II (4.8 ± 8.0% versus 4.2 ± 6.3%, P = .014). In-hospital mortality (SR-group 0.8% versus AF-group 1.7%, P = .261), major perioperative adverse cardiac and cerebrovascular events (SR-group 2.7% versus AF-group 3.5%, P = .500), and the new pacemaker implantation rate (SR-group 6.0% versus AF-group 5.9%, P = .939) were low and showed and no group difference. Logistic regression analysis showed a protective effect for preoperative SR to perioperative complications in AF patients undergoing SA (odds ratio (OR) 0.72 (95% CI 0.52 - 0.998); P = .0485). CONCLUSIONS: Concomitant SA in AF patients presenting in SR before cardiac surgery is safe, has a low perioperative risk profile, and should be carried out with almost no exceptions.

Six-Month Performance of a 3-Dimensional Annuloplasty Ring for Repair of Functional Tricuspid Regurgitation.

BACKGROUND: Functional tricuspid regurgitation (FTR) secondary to left-sided heart disease may lead to poor quality of life and reduced long-term survival. This study evaluated clinical and functional outcomes of patients undergoing tricuspid valve (TV) repair using a rigid three-dimensional ring (Contour 3D, Medtronic) concomitant with another procedure. METHODS: From September 2011 to July 2015, 112 patients (mean age 70.9 ± 9.0 years) were enrolled at 10 centers in Europe, Israel, and the United States. Inclusion criteria were FTR ≥ moderate and/or tricuspid annular diameter (TAD) ≥ 40 mm. Echocardiography was planned before surgery and at discharge with echocardiographic and clinical follow-ups performed 6 months postoperatively. RESULTS: Three fourths (74.4%) of patients had higher than moderate TR. Mean TAD was 41.0 ± 7.3 mm; 61.7% of patients were in the New York Heart Association (NYHA) class III/IV. The most common concomitant procedure was mitral valve repair (57 patients, 53.3%). The 30-day mortality rate was 0.9% (n = 1). The mean EuroSCORE II was 8.9 ± 8.4% (median: 5.9%; interquartile range: 3.5-11.5%). The observed to expected ratio (O/E) based on the median was 0.1. Six deaths occurred during follow-up (three cardiac related). Mean implanted ring size was 30.3 ± 2.7. At 6 months, 94.4% of patients showed ≤ mild TR, and 92.0% were in NYHA class I/II (p < 0.001 vs baseline for both). Mean pressure gradient across the TV was 2.0 ± 1.1 mm Hg; leaflet coaptation length was 7.5 ± 3.3 mm. CONCLUSION: The Contour 3D annuloplasty ring used for treatment of FTR substantially reduced TR for up to 6 postoperative months with low mean pressure gradients across the TV and significant improvement in NYHA class. REGISTRATION: www.ClinicalTrials.gov, NCT01532921.

Effect of Xenon Anesthesia Compared to Sevoflurane and Total Intravenous Anesthesia for Coronary Artery Bypass Graft Surgery on Postoperative Cardiac Troponin Release: An International, Multicenter, Phase 3, Single-blinded, Randomized Noninferiority Trial.

BACKGROUND: Ischemic myocardial damage accompanying coronary artery bypass graft surgery remains a clinical challenge. We investigated whether xenon anesthesia could limit myocardial damage in coronary artery bypass graft surgery patients, as has been reported for animal ischemia models. METHODS: In 17 university hospitals in France, Germany, Italy, and The Netherlands, low-risk elective, on-pump coronary artery bypass graft surgery patients were randomized to receive xenon, sevoflurane, or propofol-based total intravenous anesthesia for anesthesia maintenance. The primary outcome was the cardiac troponin I concentration in the blood 24 h postsurgery. The noninferiority margin for the mean difference in cardiac troponin I release between the xenon and sevoflurane groups was less than 0.15 ng/ml. Secondary outcomes were the safety and feasibility of xenon anesthesia. RESULTS: The first patient included at each center received xenon anesthesia for practical reasons. For all other patients, anesthesia maintenance was randomized (intention-to-treat: n = 492; per-protocol/without major protocol deviation: n = 446). Median 24-h postoperative cardiac troponin I concentrations (ng/ml [interquartile range]) were 1.14 [0.76 to 2.10] with xenon, 1.30 [0.78 to 2.67] with sevoflurane, and 1.48 [0.94 to 2.78] with total intravenous anesthesia [per-protocol]). The mean difference in cardiac troponin I release between xenon and sevoflurane was -0.09 ng/ml (95% CI, -0.30 to 0.11; per-protocol: P = 0.02). Postoperative cardiac troponin I release was significantly less with xenon than with total intravenous anesthesia (intention-to-treat: P = 0.05; per-protocol: P = 0.02). Perioperative variables and postoperative outcomes were comparable across all groups, with no safety concerns. CONCLUSIONS: In postoperative cardiac troponin I release, xenon was noninferior to sevoflurane in low-risk, on-pump coronary artery bypass graft surgery patients. Only with xenon was cardiac troponin I release less than with total intravenous anesthesia. Xenon anesthesia appeared safe and feasible.

Does Undersizing of Transcatheter Aortic Valve Bioprostheses during Valve-in-Valve Implantation Avoid Coronary Obstruction? An In Vitro Study.

Background The transcatheter aortic valve-in-valve implantation (TAViVI) is an evolving treatment strategy for degenerated surgical aortic valve bioprostheses (SAVBs) in patients with high operative risk. Although hemodynamics is excellent, there is some concern regarding coronary obstruction, especially in SAVB with externally mounted leaflet tissue, such as the Trifecta (St. Jude Medical Inc., St. Paul, Minnesota, United States). We investigated coronary flow and hydrodynamics before and after TAViVI in a SAVB with externally mounted leaflet tissue (St. Jude Medical, Trifecta) with an undersized transcatheter aortic valve bioprosthesis (Edwards Sapien XT; Edwards Lifesciences LLC, Irvine, California, United States) in an in vitro study. Materials and Methods An aortic root model was constructed incorporating geometric dimensions known as risk factors for coronary obstruction. Investigating the validity of this model, we primarily performed recommended TAViVI with the Sapien XT (size 26 mm) in a Trifecta (size 25 mm) in a mock circulation. Thereafter, hydrodynamic performance and coronary flow (left/right coronary diastolic flow [lCF/rCF]) after TAViVI with an undersized Sapien XT (size 23 mm) in a Trifecta (size 25 mm) were investigated at two different coronary ostia heights (COHs, 8 and 10 mm). Results Validation of the model led to significant coronary obstruction (p < 0.001). Undersized TAViVI showed no significant reduction with respect to coronary flow (lCF: COH 8 mm, 0.90-0.87 mL/stroke; COH 10 mm, 0.89-0.82 mL/stroke and rCF: COH 8 mm, 0.64-0.60 mL/stroke; COH 10 mm, 0.62-0.58 mL/stroke). Mean transvalvular gradients (4-5 mm Hg, p < 0.001) increased significantly after TAViVI. Conclusions In our in vitro model, undersized TAViVI with the balloon-expandable Sapien XT into a modern generation SAVB (Trifecta) successfully avoided coronary flow obstruction.

Cytomegalovirus Serostatus as Predictor for Adverse Events After Cardiac Surgery: A Prospective Observational Study.

OBJECTIVE: To clarify whether reactivated cytomegalovirus (CMV) infections in critically ill patients lead to worse outcome or just identify more severely ill patients. If CMV has a pathogenic role, latently infected (CMV-seropositive) patients should have worse outcome than seronegative patients because only seropositive patients can experience a CMV reactivation. DESIGN: Post-hoc analysis of a prospective observational study. SETTING: Single university hospital. PARTICIPANTS: The study comprised 983 consecutive patients scheduled for on-pump surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: CMV antibodies were analyzed in preoperative plasma samples. Postoperative adverse events (reintubation, low cardiac output or reinfarction, dialysis, stroke) and 30-day and 1-year mortality were evaluated prospectively. The plasma of reintubated patients and matched control patients was tested for CMV deoxyribonucleic acid, and 618 patients were found to be seropositive for CMV (63%). Among these, the risk for reintubation was increased (10% v 4%, p = 0.001). This increase remained significant after correction for confounding factors (odds ratio 2.70, p = 0.003) and was detectable from the third postoperative day throughout the whole postoperative period. Other outcome parameters were not different. Reintubated seropositive patients were more frequently CMV deoxyribonucleic acid-positive than were matched control patients (40% v 8%, p<0.001). CONCLUSIONS: CMV-seropositive patients had an increased risk of reintubation after cardiac surgery, which was associated with reactivations of their CMV infections. Additional studies should determine whether this complication may be prevented by monitoring of latently infected patients and administering antiviral treatment for reactivated CMV infections.

Atrial fibrillation burden estimates derived from intermittent rhythm monitoring are unreliable estimates of the true atrial fibrillation burden.

BACKGROUND: Estimates of atrial fibrillation (AF) burden (AFB) derived from intermittent rhythm monitoring (IRM) are increasingly being used as an outcome measure after therapeutic interventions; however, their accuracy has never been validated. The aim of this study was to compare IRM-derived AFB estimates to the true AFB as measured by implantable continuous monitoring (CM) devices. METHODS: Rhythm histories from 647 patients (mean AFB: 12 ± 22%; 687 patient·years) with CM devices were analyzed. IRM of various frequencies and durations were simulated and the obtained IRM-derived AF burdens were compared to the true AFB measured by CM. RESULTS: The relative error of the IRM burden estimates was dependent on the IRM length (P < 0.001), frequency of IRM (P < 0.001), the true AFB (P < 0.001), and its temporal aggregation (AF density, P < 0.001). In paroxysmal AF patients, the relative error even with aggressive IRM strategies was >80% of the true AFB. The relative error decreased with higher true AF burdens, lower AF densities, and higher IRM frequency or duration (P < 0.001). However, even in patients with high AF burdens and/or low AF densities, IRM estimates of AFB significantly deviated from the true AFB (relative error >20%, P < 0.001) and resulted in a substantial measurement error. CONCLUSION: IRM-derived AFB estimates are unreliable estimators of the true AFB. Particularly for paroxysmal AF patients, IRM-derived AFB estimates should not be used to evaluate outcomes after AF interventions.

Clinical outcomes and lessons learned with aortic valve repair in 508 patients.

BACKGROUND AND AIM OF THE STUDY: Aortic valve repair is an attractive alternative to valve replacement. Herein is presented the authors' single-center experience and lessons learned from 508 patients undergoing AVR, in three different groups. METHODS: Between 1993 and 2010, a total of 508 patients (148 females, 360 males; mean age 54 ± 17 years) underwent aortic valve repair. Operations included valve-sparing surgery (n = 253), isolated leaflet intervention (n = 158), and sinotubular junction (STJ) remodeling (n = 97). Aortic valve repair was defined as any primary or concomitant procedure performed at the level of the aortic valve or root for the restoration of function and/or anatomy of the valve. The mean follow up was 6.9 ± 3.8 years (range: 0-18 years; median: 6.3 years; total: 3,477 patient-years). The completeness of clinical follow up was 95%. RESULTS: The 30-day mortality with and without dissection was 4.4% (8/180) and 1.8% (6/328), respectively. Late survival without dissection, although statistically inferior, followed closely the expected general population. In total, 53 patients required a cardiac, valve-related reoperation. Among the valve-sparing group, no significant difference in freedom from reoperation at 10 years was observed between the David and Yacoub types (n = 147 (89%) versus n = 113 (79%); p = 0.373, respectively). Among patients who underwent isolated leaflet interventions, the number required to restore valve function (repair score) significantly affected the durability and incidence of reoperations (hazard ratio 1.47; 95% CI 1.1-2.0; p = 0.01), with the risk for failure being higher early after the operation. Patients with functional aortic insufficiency (AI) requiring only STJ remodeling resulted in the most durable outcome (freedom from reoperation 97.5% at 10 years). At the latest echocardiographic follow up (448 patients; total: 2,755 pt-yr; mean: 6.4 ± 3.7 years; completeness 88%), 97% of patients had AI of grade ≤ 2. CONCLUSION: Aortic valve repair is an attractive alternative to conventional replacement in many patients and pathologies. In particular, pathologies requiring multiple leaflet interventions and repair techniques may lead to suboptimal results. Leaflet quality and leaflet-adjusted root stabilization/reconstruction are key elements for durable results.

Epicardial and Endocardial Surgical Ablation of Atrial Fibrillation: Outcomes from CASE-AF Registry.

OBJECTIVES: The German CArdioSurgEry Atrial Fibrillation Registry is a prospective, multicentric registry analyzing outcomes of patients undergoing surgical ablation for atrial fibrillation as concomitant or stand-alone procedures. This data sub-analysis of the German CArdioSurgEry Atrial Fibrillation Registry aims to describe the in-hospital and one-year outcomes after concomitant surgical ablation, based on two different ablation approaches, epicardial and endocardial surgical ablation. MATERIALS AND METHODS: Between January 2017 and April 2020 seventeen German cardiosurgical units enrolled 763 consecutive patients after concomitant surgical ablation. In the epicardial group, 413 patients (54.1%), 95.6% underwent radiofrequency ablation. In the endocardial group, 350 patients (45.9%), 97.7% underwent cryoablation. 61.5% of patients in the epicardial- and 49.4% of patients in the endocardial group presenting with paroxysmal atrial fibrillation. Pre-, intra-, and post-operative data were gathered. RESULTS: Upon discharge, 32.3% (n = 109) of patients after epicardial- and 24.0% (n = 72) of patients after endocardial surgical ablation showed recurrence of AF. The in-hospital mortality rate was low, 2.2% (n = 9) in the epi- and 2.9% (n = 10) in the endocardial group. The overall one-year procedural success rate was 58.4% in the epi- and 62.2% in the endocardial group, with significant symptom improvement in both groups. The one-year mortality rate was 7.7% (n = 30) in epi- and 5.0% (n = 17) in the endocardial group. CONCLUSIONS: Concomitant surgical ablation is safe and effective with significant improvement in patient symptoms and freedom from atrial fibrillation. Adequate cardiac rhythm monitoring should be prioritized for higher-quality data acquisition.

A comprehensive evaluation of rhythm monitoring strategies for the detection of atrial fibrillation recurrence: insights from 647 continuously monitored patients and implications for monitoring after therapeutic interventions.

BACKGROUND: Intermittent rhythm monitoring (IRM) to detect atrial fibrillation (AF) recurrence is employed to evaluate the success of therapeutic interventions. In a large population of patients with continuous monitoring (CM), we investigated the sensitivity of various frequencies and durations of IRM strategies on the detection of AF recurrence, the dynamics behind AF recurrence detection, and we describe measures to evaluate temporal AF recurrence. METHODS AND RESULTS: Rhythm histories of 647 patients (mean AF burden, 0.12±0.22; median, 0.014; 687 patient-years) with implantable CM devices were reconstructed and analyzed. With the use of computationally intensive simulation, the sensitivity of IRM of various frequencies and durations on the identification of AF recurrence was evaluated. Prolonged-duration IRM was superior to shorter IRM (P<0.0001). However, even with aggressive IRM strategies, AF recurrence was not detected in a great proportion of patients. The temporal AF burden aggregation (AF density) was directly related to IRM sensitivity (P<0.0001). Even at similar AF burdens, patients with high-density AF required higher-frequency or prolonged-duration IRM to achieve the same sensitivity as in low-density AF (P<0.0001). Patients with high-density, low-burden AF benefit the most from CM for detection of AF recurrence. CONCLUSIONS: IRM follow-up is significantly inferior to CM. IRM strategies will not identify AF recurrence in a great proportion of patients at risk. Temporal AF characteristics play a significant role in AF recurrence detection with the use of IRM. For the scientific, evidence-based evaluation of AF treatments, CM should be strongly recommended. Prospective studies are required to evaluate whether CM to guide clinical management can also improve patient outcomes. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00806689.

The Strengths and Weaknesses of Left Atrial Appendage Ligation or Exclusion (LARIAT, AtriaClip, Surgical Suture).

Left atrial appendage (LAA) epicardial exclusion has been associated with addressing 2 potential deleterious consequences attributed to the LAA, namely, thrombus formation and an arrhythmogenic contributor in advanced forms of atrial fibrillation. With more than 60 years of history, the surgical exclusion of the LAA has been firmly established. Numerous approaches have been used for surgical LAA exclusion including surgical resections, suture ligation, cutting and non-cutting staples, and surgical clips. Additionally, a percutaneous epicardial LAA ligation approach has been developed. A discussion of the various epicardial LAA exclusion approaches and their efficacy will be discussed, along with the salient beneficial affects on LAA thrombus formation, LAA electrical isolation and neuroendocrine homeostasis.

A perioperative infusion of sodium bicarbonate does not improve renal function in cardiac surgery patients: a prospective observational cohort study.

INTRODUCTION: Cardiac-surgery-associated-acute-kidney-injury (CSA-AKI) is associated with increased morbidity and mortality. Recent data from patients undergoing on-pump coronary artery bypass grafting suggest that a perioperative infusion of sodium-bicarbonate may decrease the incidence of CSA-AKI. The present study aims to analyze the renoprotective effects of a 24h infusion of sodium-bicarbonate in a large, heterogeneous group of cardiac surgical patients METHODS: Starting in 4/2009, all patients undergoing cardiac surgery at our institution were enrolled in a prospective trial analyzing the relationship between preoperative cerebral oxygen saturation and postoperative organ dysfunction. We used this prospectively sampled data set to perform a cohort analysis of the renoprotective efficiency of a 24h continuous perioperative infusion of sodium-bicarbonate on the incidence of CSA-AKI that was routinely introduced in 7/2009. After exclusion of patients with endstage chronic kidney disease, off-pump procedures, and emergency cases, perioperative changes in renal function were assessed in 280 patients treated with a perioperative infusion of 4 mmol sodium-bicarbonate / kg body weight in comparison with a control cohort of 304 patients enrolled from April to June in this prospective cohort study. RESULTS: With the exception of a lower prevalence of a history of myocardial infarction and a lower preoperative use of intravenous heparin in the bicarbonate-group, no significant between group differences in patient demographics, surgical risk, type, and duration of surgery were observed. Patients in the bicarbonate group had a lower mean arterial blood pressure after induction of anesthesia, needed more fluids, more vasopressors, and a longer treatment time in the high dependency unit. Despite a higher postoperative diuresis, no differences in the incidence of AKI grade 1 to 3 and the need for renal replacement were observed. CONCLUSIONS: Routine perioperative administration of sodium bicarbonate failed to improve postoperative renal function in a large population of cardiac surgical patients.