Postoperative atrial fibrillation after isolated aortic valve replacement: a cause for concern?

Cerebrovascular events after perioperative paroxysmal atrial fibrillation in patients undergoing aortic valve replacement

BACKGROUND

Postoperative atrial fibrillation (POAF) is common after aortic valve replacement (AVR). However, the long-term risk of cerebrovascular ischemic events (CVA) associated with POAF in this scenario is not known. The study objective was to look at the long-term risk of stroke in patients undergoing AVR with POAF compared to those with no POAF, particularly in patients having a bioprosthetic valve and not discharged on anticoagulation. We also looked at the risk of peri-operative stroke and long-term mortality.

METHODS

A retrospective study of 831 patients undergoing AVR were followed up for a median of 6.5 years. The primary outcome was the occurrence of CVA after discharge, comparing those with to those without POAF, after excluding patients with a past history of atrial fibrillation (AF). They were divided into two cohorts, those having bioprosthetic valves (without oral anticoagulation), and those with a mechanical valve (with oral anticoagulation). Other outcomes studied were the incidence of early perioperative CVA comparing patients with a history of AF to those with no history, and long-term mortality in the different cohorts.

RESULTS

There was no increased risk of long-term stroke in patients with POAF when compared to those without POAF, neither in bioprosthetic valves (adjusted HR 1.14; CI 95% 0.46-2.83, P=0.78)-nor in mechanical valves (adjusted HR 1.41; CI 95% 0.55-3.65, P=0.48). Patients with a history of AF had an increased risk of perioperative stroke (OR 1.5; CI 95% 1.3-13.8, P=0.01).

CONCLUSIONS

Patients undergoing bioprosthetic AVR who develop POAF are not at an increased risk of stroke despite not being on any oral anticoagulation.

Effect of Postoperative Atrial Fibrillation After Cardiac Surgery: A Meta-Analysis

BACKGROUND

A meta-analysis study was conducted to determine how to predict the effect of postoperative atrial fibrillation after cardiac surgery.

HYPOTHESIS

Long-term mortality and cardiovascular morbidity are linked to postoperative atrial fibrillation.

METHOD

Until August 2024, a comprehensive literature study was completed, and 3486 connected studies were revised. The 38 selected studies included 241 299 cardiac surgery participants at the beginning of the study. The odds ratio (OR) and 95% confidence intervals (CIs) were used to look at the effect of atrial fibrillation after heart surgery using two-sided methods and either a fixed or random model.

RESULTS

Individuals with cardiac surgery with postoperative atrial fibrillation had significantly higher mortality at 1 year (OR, 1.39; 95% CI, 1.12-1.72, p < 0.001), mortality at 5 years (OR, 1.61; 95% CI, 1.33-1.94, p < 0.001), mortality at 10 years (OR, 1.61; 95% CI, 1.39-1.87, p < 0.001), and overall stroke (OR, 1.61; 95% CI, 1.34-1.94, p < 0.001) compared to without postoperative atrial fibrillation.

CONCLUSIONS

Individuals with cardiac surgery with postoperative atrial fibrillation had significantly higher mortality at 1 year, mortality at 5 years, mortality at 10 years, and overall stroke compared to those without postoperative atrial fibrillation. To validate this discovery, more research and caution must be implemented when interacting with its values.

Differences in Postoperative Atrial Fibrillation Incidence and Outcomes After Cardiac Surgery According to Assessment Method and Definition: A Systematic Review and Meta-Analysis

BACKGROUND

Postoperative atrial fibrillation (POAF) is the most frequent complication of cardiac surgery. Despite clinical and economic implications, ample variability in POAF assessment method and definition exist across studies. We performed a study-level meta-analysis to evaluate the influence of POAF assessment method and definition on its incidence and association with clinical outcomes.

METHODS AND RESULTS

A systematic literature search was conducted to identify studies comparing the outcomes of patients with and without POAF after cardiac surgery that also reported POAF assessment method. The primary outcome was POAF incidence. The secondary outcomes were in-hospital mortality, stroke, intensive care unit length of stay, and postoperative length of stay. Fifty-nine studies totaling 197 774 patients were included. POAF cumulative incidence was 26% (range: 7.3%-53.1%). There were no differences in POAF incidence among assessment methods (27%, [range: 7.3%-53.1%] for continuous telemetry, 27% [range: 7.9%-50%] for telemetry plus daily ECG, and 19% [range: 7.8%-42.4%] for daily ECG only; P>0.05 for all comparisons). No differences in in-hospital mortality, stroke, intensive care unit length of stay, and postoperative length of stay were found between assessment methods. No differences in POAF incidence or any other outcomes were found between POAF definitions. Continuous telemetry and telemetry plus daily ECG were associated with higher POAF incidence compared with daily ECG in studies including only patients undergoing isolated coronary artery bypass grafting.

CONCLUSIONS

POAF incidence after cardiac surgery remains high, and detection rates are variable among studies. POAF incidence and its association with adverse outcomes are not influenced by the assessment method and definition used, except in patients undergoing isolated coronary artery bypass grafting.

Atrial fibrillation after cardiac surgery: A systematic review and meta-analysis

OBJECTIVE

New-onset postoperative atrial fibrillation (POAF) after cardiac surgery is common, with rates up to 60%. POAF has been associated with early and late stroke, but its association with other cardiovascular outcomes is less known. The objective was to perform a meta-analysis of the studies reporting the association of POAF with perioperative and long-term outcomes in patients with cardiac surgery.

METHODS

We performed a systematic review and a meta-analysis of studies that presented outcomes for cardiac surgery on the basis of the presence or absence of POAF. MEDLINE, EMBASE, and the Cochrane Library were assessed; 57 studies (246,340 patients) were selected. Perioperative mortality was the primary outcome. Inverse variance method and random model were performed. Leave-one-out analysis, subgroup analyses, and metaregression were conducted.

RESULTS

POAF was associated with perioperative mortality (odds ratio [OR], 1.92; 95% confidence interval [CI], 1.58-2.33), perioperative stroke (OR, 2.17; 95% CI, 1.90-2.49), perioperative myocardial infarction (OR, 1.28; 95% CI, 1.06-1.54), perioperative acute renal failure (OR, 2.74; 95% CI, 2.42-3.11), hospital (standardized mean difference, 0.80; 95% CI, 0.53-1.07) and intensive care unit stay (standardized mean difference, 0.55; 95% CI, 0.24-0.86), long-term mortality (incidence rate ratio [IRR], 1.54; 95% CI, 1.40-1.69), long-term stroke (IRR, 1.33; 95% CI, 1.21-1.46), and longstanding persistent atrial fibrillation (IRR, 4.73; 95% CI, 3.36-6.66).

CONCLUSIONS

The results suggest that POAF after cardiac surgery is associated with an increased occurrence of most short- and long-term cardiovascular adverse events. However, the causality of this association remains to be established.

Impact of atrial fibrillation on in-hospital outcomes among hospitalizations for cardiac surgery: an analysis of the National Inpatient Sample

The short-term impact of atrial fibrillation (AF) on cardiac surgery hospitalizations has been previously reported in cohorts of various sizes, but results have been variable. Using the 2005-2014 National Inpatient Sample, we identified all adult hospitalizations for cardiac surgery using the International Classification of Diseases, Ninth Revision, Clinical Modification as any procedure code and AF as any diagnosis code. We estimated the impact of AF on inpatient mortality, length of stay (LOS), and cost of hospitalization using survey-weighted, multivariable logistic, accelerated failure-time log-normal, and log-transformed linear regressions, respectively. Additionally, we exact-matched AF to non-AF hospitalizations on various confounders for the same outcomes. A total of 1,269,414 hospitalizations were noted for cardiac surgery during the study period. Coexistent AF was found in 44.9% of these hospitalizations. Overall mean age was 65.6 years, 40.9% were female, mean LOS was 11.6 days, and inpatient mortality was 4.5%. Stroke rate was lower in AF hospitalizations (1.8% vs 2.1%, p<0.001). Mortality was lower in the AF (3.9%) versus the non-AF (5%) group (exact-matched OR or emOR=0.48, 95% CI 0.29 to 0.80, p<0.001; 987 matched pairs, n=2423), with similar results after procedural stratification: isolated valve replacement/repair (emOR=0.38, p<0.001), isolated coronary artery bypass graft (CABG) (emOR=0.33, p<0.001), and CABG with valve replacement/repair (emOR=0.55, p<0.001). A 12% increase was seen in LOS in the AF subgroup (exact-matched time ratio=1.12, 95% CI 1.10 to 1.14, p<0.001) among hospitalizations which underwent valve replacement/repair with or without CABG. Hospitalizations for cardiac surgery which had coexistent AF were found to have lower inpatient mortality risk and stroke prevalence but higher LOS and hospitalization costs compared with hospitalizations without AF.

Rhythm outcomes after aortic valve surgery: Treatment and evolution of new-onset atrial fibrillation

BACKGROUND

The impact of new-onset atrial fibrillation (AF) after aortic valve (AV) surgery on mid- and long-term outcomes is under debate. Here, we sought to follow up heart rhythms after AV surgery, and to evaluate the mid-term prognosis and effectiveness of treatment for patients with new-onset AF.

METHODS

This single-center cohort study included 978 consecutive patients (median age, 59 years; male, 68.5%) who underwent surgical AV procedures between 2017 and 2018. All patients with postoperative new-onset AF were treated with Class III antiarrhythmic drugs with or without electrical cardioversion (rhythm control). Status of survival, stroke, and rhythm outcomes were collected and compared between patients with and without new-onset AF.

RESULTS

New-onset AF was detected in 256 (26.2%) patients. For them, postoperative survival was comparable with those without new-onset AF (1-year: 96.1% vs. 99.3%; adjusted P = .30), but rate of stroke was significantly higher (1-year: 4.0% vs. 2.2%; adjusted P = .020). With rhythm control management, the 3-month and 1-year rates of paroxysmal or persistent AF between patients with and without new-onset AF were 5.1% versus 1.3% and 7.5% versus 2.1%, respectively (both P < .001). Multivariate models showed that advanced age, impaired ejection fraction, new-onset AF and discontinuation of beta-blockers were predictors of AF at 1 year.

CONCLUSIONS

In most cases, new-onset AF after AV surgery could be effectively converted and suppressed by rhythm control therapy. Nevertheless, new-onset AF predisposed patients to higher risks of stroke and AF within 1 year, for whom prophylactic procedures and continuous beta-blockers could be beneficial.

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.

Postoperative Atrial Fibrillation or Flutter Following Transcatheter or Surgical Aortic Valve Replacement: PARTNER 3 Trial

OBJECTIVES

The aim of this study was to assess the incidence and prognostic impact of early and late postoperative atrial fibrillation or flutter (POAF) in patients with severe aortic stenosis (AS) treated with transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR).

BACKGROUND

There is an ongoing controversy regarding the incidence, recurrence rate, and prognostic impact of early (in-hospital) POAF and late (postdischarge) POAF in patients with AS undergoing TAVR or SAVR.

METHODS

In the PARTNER (Placement of Aortic Transcatheter Valve) 3 trial, patients with severe AS at low surgical risk were randomized to TAVR or SAVR. Analyses were performed in the as-treated population excluding patients with preexistent atrial fibrillation or flutter.

RESULTS

Among 781 patients included in the analysis, early POAF occurred in 152 (19.5%) (18 of 415 [4.3%] and 134 of 366 [36.6%] following TAVR and SAVR, respectively). Following discharge, 58 new or recurrent late POAF events occurred within 1 year following the index procedure in 55 of 781 patients (7.0%). Early POAF was not an independent predictor of late POAF following discharge (odds ratio: 1.04; 95% CI: 0.52-2.08; P = 0.90). Following adjustment, early POAF was not an independent predictor of the composite outcome of death, stroke, or rehospitalization (hazard ratio: 1.10; 95% CI: 0.64-1.92; P = 0.72), whereas late POAF was associated with an increased adjusted risk for the composite outcome (hazard ratio: 8.90; 95% CI: 5.02-15.74; P < 0.0001), irrespective of treatment modality.

CONCLUSIONS

In the PARTNER 3 trial, early POAF was more frequent following SAVR compared with TAVR. Late POAF, but not early POAF, was significantly associated with worse outcomes at 2 years, irrespective of treatment modality.

Late incidence and recurrence of new-onset atrial fibrillation after isolated surgical aortic valve replacement

OBJECTIVES

Atrial fibrillation (AF) is a common complication after cardiac surgery. More knowledge is needed about long-term AF recurrence and adverse outcomes related to new-onset AF (NOAF) during the index hospitalization.

METHODS

A total of 1073 patients underwent isolated surgical aortic valve replacement at the 4 participating hospitals (2002-2014). After the exclusion of patients with a history of any preoperative AF, the final study population included 529 patients in the bioprosthetic and 253 patients in the mechanical valve prosthesis cohort. Median follow-up time was 5.4 (interquartile range, 3.4-8.2) years in the combined cohort.

RESULTS

Altogether 333 (42.6%) patients had in-hospital NOAF and 250 (32.0%) AF after hospital discharge. In the mechanical cohort, 64 (25.3%) experienced in-hospital NOAF and 74 (29.2%) AF after hospital discharge, whereas in the bioprosthetic cohort, 269 (50.9%) patients had in-hospital NOAF and 176 (33.3%) AF after hospital discharge. Patients with NOAF during the index hospital stay had a multifold risk of AF after hospital discharge in the combined cohort (hazard ratio [HR], 3.68; 95% confidence interval [CI], 2.82-4.81; P < .0001) as well as in both cohorts separately (bioprosthetic: HR, 4.35; 95% CI, 3.05-6.22; P < .001; mechanical: HR, 2.54; 95% CI, 1.59-4.03; P < .001). Patients with an in-hospital NOAF also had a significantly higher adjusted risk of death during the follow-up in the mechanical (HR, 2.05; 95% CI, 1.10-3.82; P = .025) and bioprosthetic (HR, 1.63; 95% CI, 1.17-2.28; P = .004) valve prosthesis cohorts.

CONCLUSIONS

NOAF during the index hospitalization is associated with a 2- to 4-fold risk of later AF and 1.6- to 2.0-fold risk of all-cause mortality after mechanical and bioprosthetic surgical aortic valve replacement.

Postoperative Atrial Fibrillation After Cardiac Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Postoperative atrial fibrillation (POAF) after cardiac surgery is associated with longer hospital stay and increased in-hospital death and stroke, but its long-term implications remain incompletely understood. A systematic literature review was undertaken to investigate the impact of POAF on long-term death and stroke in adult patients who undergo cardiac operations.

METHODS

Electronic databases (Cochrane, Embase, Ovid MEDLINE, and PubMed) were queried from inception to October 2018. Included studies compared long-term outcomes after cardiac operations in patients with and without POAF. Adjusted and unadjusted meta-analyses examined death, stroke, and major adverse cardiac and cerebrovascular events. Risk of bias was evaluated with the Newcastle-Ottawa Scale.

RESULTS

The inclusion criteria were met by 32 studies describing 155,575 patients who had undergone cardiac operations. POAF occurred in 36,988 patients (23.7%). Meta-analysis of 10 studies (44,367 patients) demonstrated increased 1-year death in patients with POAF (odds ratio, 2.60; 95% confidence interval, 2-3.38; P < .01). Aggregate adjusted hazard of death (16 studies, n = 84,295) was also increased in patients with POAF (hazard ratio, 1.25; 95% confidence interval, 1.2-1.3; P < .01).

CONCLUSIONS

This systematic review and meta-analysis identified an association between POAF and long-term death after cardiac surgery. More comprehensive POAF prevention and management, including more stringent follow-up for POAF recurrence after hospital discharge, may be indicated. The included studies used inconsistent definitions of POAF and variable exclusion criteria; however, estimates of heterogeneity are low. Differences in preoperative comorbidities, such as age, ejection fraction, and obesity, may not be fully accounted for in adjusted analyses. Future work is required to delineate mechanisms linking POAF and death in this population.

New Onset Atrial Fibrillation Following Transcatheter and Surgical Aortic Valve Replacement: A Systematic Review and Meta-Analysis

BACKGROUND

New-onset atrial fibrillation (NOAF) is a well-recognised, although variably reported complication following surgical aortic valve replacement (SAVR). Rates of NOAF following transcatheter aortic valve implantation (TAVI) seem to be notably less than SAVR, even though this population is typically older and of higher risk. The aim of this study was to determine the prevalence of NOAF in both these populations and associated postoperative outcomes.

METHODS

We conducted a systematic review and meta-analysis of studies reporting rates of NOAF post SAVR or TAVI, along with early postoperative outcomes. Twenty-five (25) studies with a total of 13,010 patients were included in the final analysis.

RESULTS

The prevalence of NOAF post SAVR was 0.4 (95% CI 0.36-0.44) and post TAVI 0.15 (95% CI 0.11-0.18). NOAF was associated with an increased risk of postoperative cerebrovascular accident (CVA) for SAVR and TAVI (RR 1.44 95% CI 1.01-2.06 and RR 2.24 95% CI 1.46-3.45 respectively). NOAF was associated with increased mortality in the TAVI group (RR 3.02 95% CI 1.55-5.9) but not the SAVR group (RR 1.00, 95% CI 0.54-1.84). Hospital length of stay was increased for both TAVI and SAVR patients with NOAF (MD 2.54 days, 95% CI 2.0-3.00) and (MD 1.64 days, 95% CI 0.04-3.24 respectively).

CONCLUSIONS

The prevalence of NOAF is significantly less following TAVI, as compared to SAVR. While NOAF is associated with increased risk of postoperative stroke for both groups, for TAVI alone NOAF confers increased risk of early mortality.

Revisiting Atrial Fibrillation in the Transcatheter Aortic Valve Replacement Era

Atrial fibrillation (AF) is a known complication of many cardiac procedures, including those undergoing surgical aortic valve replacement (SAVR). In the transcatheter aortic valve replacement (TAVR) era, AF has been noted not only to be present in these patients but also associated with morbidity and mortality. In this article, we first outline the significance of AF in general and then more specifically in patients undergoing cardiac surgery. We then compare and contrast specific clinical issues related to AF in patients with aortic stenosis undergoing aortic valve replacement, traditionally with SAVR, but now increasingly more common with TAVR.

Atrial fibrillation in patients undergoing transcatheter aortic valve implantation: epidemiology, timing, predictors, and outcome

Atrial fibrillation (AF) is a common arrhythmia in patients with aortic stenosis. When these patients are treated medically or by surgical aortic valve replacement, AF is associated with increased risk of adverse events including death. Growing evidence suggests a significant impact of AF on outcomes also in patients with aortic valve stenosis undergoing transcatheter aortic valve implantation (TAVI). Conversely, limited evidence is available regarding the optimal management of this condition. This review aims to summarize prevalence, pathophysiology, prognosis, and treatment of AF in patients undergoing TAVI.

Teaching an Old Dog New Tricks: Colchicine in Cardiovascular Medicine

Colchicine is one of the oldest known drugs that remains part of the current pharmacopeia. Recent studies have examined the efficacy of colchicine in cardiology with promising results. We conducted a search of electronic databases for studies on colchicine in cardiovascular medicine published through October 2016. As the utilization of colchicine in the management of cardiac conditions grows, it is paramount that internists and cardiologists are familiarized with its benefits and risks. We present a comprehensive review of the role of colchicine in the management of cardiovascular diseases with a strong emphasis on side effects and potential drug interactions.

Atrial Fibrillation is Associated with Increased Pacemaker Implantation Rates in the Placement of AoRTic Transcatheter Valve (PARTNER) Trial

Atrial fibrillation (AF) is associated with worse outcomes in many cardiovascular diseases. There are few data examining pacemaker implantation rates and indications in patients with AF who undergo transcatheter aortic valve replacement (TAVR). To examine the impact of AF on the incidence of and indications for pacemakers in patients undergoing TAVR, we evaluated data of 1723 patients without pre-existing pacemakers who underwent TAVR in the Placement of AoRTic TraNscathetER Valve (PARTNER) trial. Permanent pacemaker implantation rates and indications were compared in groups based on baseline and discharge heart rhythm: sinus rhythm (SR) vs. AF. 1211 patients manifested SR at baseline/SR at discharge (SR/SR), 105 SR baseline/AF discharge (SR/AF), and 407 AF baseline/AF discharge (AF/AF). Patients who developed and were discharged with AF (SR/AF) had the highest rates of pacemaker implantation at 30 days (13.7% SR/AF vs. 5.4% SR/SR, p=0.0008 and 5.9% AF/AF, p=0.008) and 1 year (17.7% SR/AF vs. 7.1% SR/SR, p=0.0002 and 8.1% AF/AF, p=0.0034). Conversion from SR to AF by discharge was an independent predictor of increased pacemaker implantation at 30 days (HR 2.19 vs. SR/SR, 95% CI 1.23-3.93, p=0.008) and 1 year (HR 1.91 vs. SR/SR, 95% CI 1.33-3.80). Pacemaker indications differed between groups, with relatively more implanted in the AF groups for sick sinus syndrome (SSS) versus AV block. In conclusion, conversion to AF is an independent predictor of permanent pacemaker implantation in TAVR patients. Indications differ depending on heart rhythm, with patients in AF manifesting clinically significant tachy-brady syndrome versus AV block.

Preoperative Antihypertensive Medication in Relation to Postoperative Atrial Fibrillation in Patients Undergoing Cardiac Surgery: A Meta-Analysis

Background. We undertake a systematic review and meta-analysis to evaluate the effect of preoperative hypertension and preoperative antihypertensive medication to postoperative atrial fibrillation (POAF) in patients undergoing cardiac surgery. Methods. We searched PubMed, Embase, and Cochrane Library (from inception to March 2016) for eligible studies. The outcomes were the effects of preoperative hypertension, preoperative calcium antagonists regimen, preoperative ACE inhibitors regimen, and preoperative beta blocking agents regimen with POAF. We calculated pooled risk ratios (OR) and 95% CIs using random- or fixed-effects models. Results. Twenty-five trials involving 130087 patients were listed. Meta-analysis showed that the number of preoperative hypertension patients in POAF group was significantly higher (P < 0.05), while we found that there are no significant differences between two groups in Asia patients by subgroup analysis, which is in contrast to other outcomes. Compared with the Non-POAF group, the number of patients who used calcium antagonists and ACE inhibitors preoperatively in POAF group was significantly higher (P < 0.05). And we found that there were no significant differences between two groups of preoperative beta blocking agents used (P = 0.08). Conclusions. Preoperative hypertension and preoperative antihypertensive medication in patients undergoing cardiac operations seem to be associated with higher risk of POAF.

Long-term consequences of atrial fibrillation after aortic valve replacement

Background

Atrial fibrillation is a common complication after cardiac surgery, but the risk factors and long-term outcome after primary isolated aortic valve replacement remains to be clarified.

Methods

A single-center retrospective study was conducted on 157 patients who underwent first-time isolated aortic valve replacement between April 1999 and February 2015. Fifty-eight patients developed new-onset atrial fibrillation within 6 months postoperatively, and they were compared with patients who remained in sinus rhythm. Multivariate analyses, which incorporated the propensity score patient matching technique, were conducted to evaluate the long-term outcome of new-onset postoperative atrial fibrillation and identify patients at risk of developing this arrhythmia.

Results

At a mean follow-up of 52.4 months (range 8.4–200.7 months), mortality was significantly higher in patients who developed atrial fibrillation compared to those who remained in sinus rhythm (2.8%/patient-year vs. 0.2%/patient-year, respectively; p < 0.05). Patients developing atrial fibrillation were also at an independently increased risk of stroke and readmission during follow-up. Risk analysis revealed that advanced age (>70 years) and absence of a postoperative β-blocker were predictors of atrial fibrillation.

Conclusions

New-onset atrial fibrillation after first-time isolated aortic valve replacement correlated significantly with late morbidity and mortality. Advanced age and absence of a postoperative β-blocker may increase the incidence of atrial fibrillation.

Atrial Fibrillation Is Associated With Increased Mortality in Patients Undergoing Transcatheter Aortic Valve Replacement: Insights From the Placement of Aortic Transcatheter Valve (PARTNER) Trial

BACKGROUND

This study sought to evaluate the impact of atrial fibrillation (AF) on clinical outcomes in patients undergoing transcatheter aortic valve replacement.

METHODS AND RESULTS

Data were evaluated in 1879 patients with baseline and discharge ECGs who underwent transcatheter aortic valve replacement in the Placement of AoRTic TraNscathetER Valve (PARTNER) trial. A total of 1262 patients manifested sinus rhythm (SR) at baseline/SR at discharge, 113 SR baseline/AF discharge, and 470 AF baseline/AF discharge. Patients who converted from SR to AF by discharge had the highest rates of all-cause mortality at 30 days (P<0.0001 across all groups; 14.2% SR/AF versus 2.6% SR/SR; adjusted hazard ratio [HR]=3.41; P=0.0002) and over 2-fold difference at 1 year (P<0.0001 across all groups; 35.7% SR/AF versus 15.8% SR/SR; adjusted HR=2.14; P<0.0001). The presence of AF on baseline or discharge ECG was a predictor of 1-year mortality (adjusted HR=2.14 for SR/AF group and HR=1.88 for AF/AF groups; P<0.0001 for both groups versus SR/SR). For patients discharged in AF, those with lower ventricular response (ie, <90 bpm) experienced less 1-year all-cause mortality (HR=0.74; P=0.04).

CONCLUSIONS

After transcatheter aortic valve replacement, the presence of AF at discharge, and particularly, the conversion to AF by discharge and higher ventricular response are associated with increased mortality. These data underscore the deleterious impact of AF, as well as the need for targeted interventions to improve clinical outcomes, in patients undergoing transcatheter aortic valve replacement.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00530894.

Duration of Postoperative Atrial Fibrillation After Cardiac Surgery Is Associated With Worsened Long-Term Survival

BACKGROUND

Studies of the effects of postoperative atrial fibrillation (poAF) on long-term survival are conflicting, likely because of comorbidities that occur with poAF and the patient populations studied. Furthermore, the effects of poAF duration on long-term survival are poorly understood.

METHODS

We utilized a prospectively collected database on outcomes of cardiac surgery at a large tertiary care institution between August 2001 and December 2010 with survival follow-up through June 2015 to analyze long-term survival of patients with poAF. In addition, we identified patient- and procedure-related variables associated with poAF, and estimated overall comorbidity burden using the Elixhauser comorbidity index. Survival was compared between patients with poAF (n = 513) and a propensity score matched control cohort, both for all patients and separately for subgroups of patients with poAF lasting less than 2 days (n = 218) and patients with prolonged poAF (n = 265).

RESULTS

Patients with poAF were older and had a higher burden of comorbidities. Survival was significantly worse for patients with poAF than for the matched control group (hazard ratio 1.43, 95% confidence interval: 1.11 to 1.86). That was driven by decreased survival among patients with prolonged poAF (hazard ratio 1.97, 95% confidence interval: 1.37 to 2.80), whereas survival of patients with poAF for less than 2 days was not significantly different from that of matched controls (hazard ratio 0.91, 95% confidence interval: 0.60 to 1.39).

CONCLUSIONS

After close matching based on comorbidity burden, prolonged poAF is still associated with decreased survival. Therefore, vigilance is warranted in monitoring and treating patients with prolonged poAF after cardiac surgery.

Abnormal heart rate variability and atrial fibrillation after aortic surgery

Introduction

Complete denervation of transplanted heart exerts protective effect against postoperative atrial fibrillation; various degrees of autonomic denervation appear also after transection of ascending aorta during surgery for aortic aneurysm.

Objective

This study aimed to evaluate if the level of cardiac denervation obtained by resection of ascending aorta could exert any effect on postoperative atrial fibrillation incidence.

Methods

We retrospectively analysed the clinical records of 67 patients submitted to graft replacement of ascending aorta (group A) and 132 with aortic valve replacement (group B); all episodes of postoperative atrial fibrillation occurred during the 1-month follow-up have been reported. Heart Rate Variability parameters were obtained from a 24-h Holter recording; clinical, echocardiographic and treatment data were also evaluated.

Results

Overall, 45% of patients (group A 43%, group B 46%) presented at least one episode of postoperative atrial fibrillation. Older age (but not gender, abnormal glucose tolerance, ejection fraction, left atrial diameter) was correlated with incidence of postoperative atrial fibrillation. Only among a subgroup of patients with aortic transection and signs of greater autonomic derangement (heart rate variability parameters below the median and mean heart rate over the 75^th percentile), possibly indicating more profound autonomic denervation, a lower incidence of postoperative atrial fibrillation was observed (22% vs. 54%).

Conclusion

Transection of ascending aorta for repair of an aortic aneurysm did not confer any significant protective effect from postoperative atrial fibrillation in comparison to patients with intact ascending aorta. It could be speculated that a limited and heterogeneous cardiac denervation was produced by the intervention, creating an eletrophysiological substrate for the high incidence of postoperative atrial fibrillation observed.

Effects of levosimendan in patients with left ventricular hypertrophy undergoing aortic valve replacement

BACKGROUND

Left ventricular hypertrophy is associated with adverse outcomes, including death, during cardiac surgery. This may be facilitated by an increased oxygen demand and diastolic dysfunction. Levosimendan augments haemodynamics without further oxygen consumption and improves echocardiographic indices of diastolic dysfunction. This study aimed to describe the haemodynamic effects of short-term pre- and intra-operative levosimendan infusion including advanced echocardiographic measures of diastolic and systolic heart function.

METHODS

The study was randomised, double-blinded and placebo-controlled performed at a single-centre university hospital. Patients with left ventricular hypertrophy and ejection fraction > 45% scheduled for single procedure aortic valve replacement were included and randomised to infusion of either levosimendan 0.1 μg/kg/min or placebo from 4 h before anaesthesia to the end of surgery. Outcome measures were echocardiographic indices of left ventricular diastolic function: E/e' (primary endpoint), e', e'/a' and indices of systolic function: longitudinal strain, ejection fraction and s'. Patients were followed until 6 months after surgery. In addition, invasive haemodynamic measures were obtained perioperatively.

RESULTS

The trial was prematurely terminated due to an overall high incidence of post-operative atrial fibrillation (15/20, P = 0.002) after inclusion of 20 patients. The relative decrease in perioperative cardiac index was lower (P = 0.016) in the levosimendan group. There was no difference in E/e', and similar results were found for all measures of systolic function.

CONCLUSION

Short-term levosimendan caused a transient relative increase in cardiac index, but no effect was seen on the first post-operative day and up to 6 months post-operatively with indices of systolic and diastolic heart function.

Transcatheter aortic valve replacement has improved short-term but similar midterm outcomes in isolated aortic valve replacement after prior coronary artery bypass grafting

BACKGROUND

An increasing number of patients with prior coronary artery bypass grafting (CABG) now present with severe aortic stenosis. The proposed benefit of surgical (SAVR) vs transcatheter aortic valve replacement (TAVR) is unknown. The objective of this study was to compare short-term and midterm outcomes of patients undergoing isolated SAVR vs TAVR in those with prior CABG.

METHODS

A retrospective analysis was performed of 255 patients who underwent isolated SAVR after prior CABG from January 2002 to February 2013 at Emory University. Outcomes of 148 patients undergoing SAVR (2002 to 2013) and 107 undergoing TAVR (2007 to 2013) were compared using multivariable logistic regression and analysis of variance techniques, adjusting for The Society of Thoracic Surgeons (STS) risk score. Kaplan-Meier plots were used to determine survival rates, and midterm survival between groups was compared using the Cox proportional hazards model.

RESULTS

TAVR patients were older (79.8 ± 7.9 years vs 72.5 ± 8.8 years, p < 0.001) but were gender equivalent (female: 24% vs 22%, p = 0.61). The preoperative ejection fraction was similar between groups (TAVR: 0.433 ± 0.131 vs SAVR: 0.469 ± 0.148%, p = 0.60). The TAVR group had a significantly higher the STS risk scores (11.8% vs 7.1%, p < 0.001). All-cause 30-day mortality was 1.9% for TAVR and 4.1% for SAVR (p = 0.32), a result that marginally favors TAVR after risk adjustment (adjusted odds ratio, 0.19; p = 0.07). Postoperative morbidity and resource utilization was significantly higher in the SAVR patients. Midterm survival was similar between the two groups after adjustment (adjusted hazard ratio, 0.78, p = 0.46).

CONCLUSIONS

Excellent outcomes can be achieved in SAVR or TAVR after prior CABG. Although TAVR improves short-term outcomes and resource utilization compared with SAVR, midterm mortality outcomes are similar.

Anticoagulation strategies for the management of postoperative atrial fibrillation

Patients undergoing thoracic and cardiac procedures are at the highest risk for postoperative atrial fibrillation (POAF). POAF is associated with poor short-term and long-term outcomes, including high rates of early and late stroke, and late mortality. Patients with POAF that persists for longer than 48 hours should be anticoagulated on warfarin. Three new oral anticoagulants are available for the treatment of nonvalvular atrial fibrillation and have been found to be as efficacious or superior to warfarin in the prevention of stroke in high-risk patients, with similar to lower rates of major bleeding, and lower rates of intracranial hemorrhage.