Postoperative Permanent Pacemaker Research Articles

Early hemodynamics and clinical outcomes of isolated aortic valve replacement with stentless or transcatheter valve in intermediate-risk patients

ObjectiveStentless aortic valves have been developed to overcome obstructive limitations associated with stented bioprostheses. The aim of the current multi-institutional study was to compare hemodynamics of transcatheter (TAVR) and the Freedom SOLO Stentless (FS) valve in an intermediate risk population undergoing surgical aortic valve replacement. MethodsFrom 2010 to 2014, 420 consecutive patients underwent isolated surgical aortic valve replacement with FS and 375 patients underwent TAVR. Only patients with intermediate operative risk (Society of Thoracic Surgeons score 4-10) and small aortic annulus (≤23 mm) were included. After a propensity matched analysis 142 patients in each group were selected. Thirty-day postoperative clinical and echocardiographic parameters were evaluated. ResultsMean prosthesis diameter was 22.2 ± 0.9 mm for FS and 22.4 ± 1.0 mm for TAVR. In-hospital mortality was 2.1% for FS and 6.3% for TAVR (P = .02). Postoperative FS peak gradients were 19.1 ± 9.6 mm Hg (mean 10.8 ± 5.9 mm Hg); TAVR peak gradients were 20.2 ± 9.5 mm Hg (mean 10.7 ± 6.9 mm Hg) P = .57 (P = .88). Postoperative effective orifice area was 1.93 ± 0.52 cm2 for FS and 1.83 ± 0.3 cm2 for TAVR (P = .65). There was no prostheses-patient mismatch in either group. Postoperative grade 2-3 paravalvular leak was present in 3.5% for TAVR and 0.7% for FS. Postoperative permanent pacemaker implant rate was 12% for TAVR and only 1 case (0.7%) in the FS group (P < .001). ConclusionsIn patients with small aortic annulus and intermediate risk, both FS and TAVR demonstrated similar excellent hemodynamic performance. TAVR demonstrated greater mortality and rates of pacemaker insertion. Further studies are warranted to validate TAVR indications in this subset of patients.

Conduction Disorders After Sutureless Aortic Valve Replacement

Sutureless self-expandable aortic bioprostheses rely on radial forces for stabilization, raising concern that these devices may increase the risk of postoperative conduction disease. The purpose of this study was to determine the incidence of conduction disorders after sutureless aortic valve replacement (AVR) with the Perceval S (Sorin Group, Saluggia, Italy) bioprosthesis. Between June 2011 and March 2013, 108 consecutive patients underwent sutureless AVR with the Perceval S prosthesis. Six patients (6%) had a permanent pacemaker (PPM) preoperatively and were excluded from the present study. Mean electrocardiographic follow-up was 14.6 ± 6.0 months. Mean age was 79.2 ± 4.8 years (52% female). During the postoperative period, 34 patients (34%) had first-degree atrioventricular block, 2 (2%) had Mobitz-II atrioventricular block, and 16 (16%) had complete atrioventricular block. New-onset left bundle branch block and right bundle branch block were observed in 33patients (33%) and 22 patients (22%), respectively. Inhospital postoperative PPM implantation was required in 23 patients (23%). Preoperative aortic valve area, age more than 85 years, and preoperative right bundle branch block were found to be independently associated with inhospital PPM implantation or new-onset postoperative conduction disorder. At follow-up, 3 more patients (3%) underwent PPM implantation. The cumulative incidences of PPM dependency and ventricular pacing more than 25% of the time were 18% ± 11% and 21% ± 10%, respectively, at 18 months. In the present study, the postoperative PPM implantation rate (23%) after sutureless AVR with the Perceval S prosthesis was high. Surgical strategies aimed at mitigating this risk should be further investigated.

A Novel Minimally Invasive Approach for Surgical Septal Myectomy

BackgroundTransaortic septal myectomy is the gold standard for the treatment of symptomatic hypertrophic obstructive cardiomyopathy that is refractory to medical therapy. The aim of this study was to assess early outcomes of minimally invasive septal myectomy performed through a right anterior minithoracotomy. MethodsBetween 2011 and 2014, 24 consecutive patients underwent isolated septal myectomy through a 4-5–cm right parasternal minithoracotomy. Perioperative clinical and echocardiographic outcomes in these patients were compared with those of a historical cohort of 26 consecutive patients who underwent isolated septal myectomy performed through a median sternotomy between 2002 and 2010. ResultsAge and sex distribution were similar between the groups. Median aortic cross-clamp time was 57 minutes in the minithoracotomy group vs 43 minutes in the sternotomy group (P = 0.149). There was no in-hospital mortality in either group. Intraoperative conversion to sternotomy was required in 1 patient. Postoperative permanent pacemaker implantation was required in 5 patients from each group (P = 0.999). Both groups demonstrated similar reductions in left ventricular outflow tract gradient and septal thickness. Residual obstructive systolic anterior motion of the mitral valve was observed in 2 patients (8%) in the minithoracotomy group and 1 patient (4%) in the sternotomy group (P = 0.602). ConclusionsThis study demonstrates the feasibility of transaortic septal myectomy through a right minithoracotomy. Our early results suggest that this technique yields clinical and echocardiographic outcomes similar to those obtained with standard sternotomy.

Predictors of Permanent Pacemaker Implantation After Coronary Artery Bypass Grafting and Valve Surgery in Adult Patients in Current Surgical Era.

BackgroundPermanent pacemaker (PPM) implantation after cardiac surgery is required in 0.4-6% of patients depending on cardiac surgery type. PPM implantation in the early postoperative period may reduce morbidity and postoperative hospital stay. We performed a retrospective review of electronic medical records of adult patients with coronary artery bypass grafting (CABG), valve surgery, or both, over a 3-year period. Our aim was to identify predictors of PPM requirements and PPM dependency on follow-up in the current surgical era.MethodsAfter exclusion of patients with congenital heart disease, patients who already had a PPM or implantable cardioverter defibrillator (ICD), and patients with an indication for PPM or ICD before surgery, we identified 1,234 adult patients who underwent cardiac surgery between January 2007 and December 2009. A retrospective review of electronic medical records and pacemaker clinic data was performed.ResultsPatients’ mean age was 46.65 ± 16 years, and 59% were males. CABG was performed in 575 (46.6%) cases, aortic valve replacement in 263 (21.3%), mitral valve replacement in 333 (27%), and tricuspid valve replacement in 76 patients (6.2%). Twenty patients (1.6%) required implantation of a PPM postoperatively. Indications for PPM implantation included complete atrioventricular (AV) block in 13 (65%), sick sinus syndrome in three (15%), and atrial fibrillation (AF) with a slow ventricular rate in four (20%). Predictors for PPM requirement by multivariate analysis were the presence of pulmonary hypertension (P-HTN), reoperation, and left bundle branch block (LBBB) (P < 0.05). Late follow-up was available in 18 patients, at 84.5 ± 30 months. Eleven patients (61%) were PPM dependent on long-term follow-up.ConclusionsPatients at high risk for PPM implantation after cardiac surgery include those with P-HTN, reoperation, and pre-existing LBBB. Of those receiving a PPM, about one-third will recover at least partially at long-term follow-up. We recommend preoperative assessment for risk of requiring postoperative PPM, to counsel patients about this risk and early PPM implantation in high-risk patients who are PPM dependent after surgery.

Pacemaker implantation in pediatric heart transplant recipients: Predictors, outcomes, and impact on survival.

Little is known about the incidence of permanent pacemaker (PPM) implantation after heart transplantation (HTx) in the pediatric population. The purpose of this study was to investigate the incidence, predictors, and outcomes of acute need for PPM implantation in pediatric HTx recipients. We queried the United Network for Organ Sharing (UNOS) database for all pediatric (age <18 years) patients who received HTx (1994-2014). Regression models are reported for prediction of PPM implantation. A total of 6156 patients were analyzed, of whom 69 (1.1%) required posttransplant PPM implantation acutely. PPM use decreased over the study period (hazard ratio [HR] 0.95, P = .01). Compared with the non-PPM group, PPM group was more likely to be older (10 vs 5.0 years, P <.001), used antiarrhythmics (35.6% vs 18.3%, P = .006), required intraaortic balloon pump (2.9% vs 0.5%, P = .049), and had undergone biatrial anastomosis (68.1% vs 48.2%, P = .007). In a multivariable model, PPM implantation was predicted by higher donor age (HR 1.05, P = .002), biatrial anastomosis (HR 2.53, P = .04) and antiarrhythmic use (HR 2.12, P = .02). After adjusting for baseline characteristics, PPM recipients were at increased risk for posttransplant infection (47.8% vs 26.4%, P = .001) and dialysis (15.9% vs 6.6%, P = .003). Adjusted graft survival did not differ between the 2 groups (P = .78). Acute postoperative PPM implantation in pediatric HTx recipients is rare and has decreased over time. Acute PPM use is associated with biatrial anastomosis, antiarrhythmic use, and older donor age. Although PPM recipients had higher incidences of infections and dialysis, PPM implantation did not adversely impact survival.

Effect of Surgical Atrial Fibrillation Ablation at the Time of Cardiac Surgery on Risk of Postoperative Pacemaker Implantation

The aim of this study was to retrospectively investigate whether performing surgical atrial fibrillation (AF) ablation in conjunction with cardiac surgery (CS) increases the risk for postoperative permanent pacemaker (PPM) requirement. The 30-day risk for PPM requirement was analyzed in consecutive patients who underwent CS from January 2007 to August 27, 2013. Patients were divided into 3 groups: (1) those who underwent AF ablation concomitant with CS (AF ABL), (2) patients with any history of AF who underwent surgery who did not undergo ablation (AF NO ABL), and (3) those with no histories of AF who underwent surgery (NO AF). Logistic regression analysis was performed adjusting for age, gender, and surgery type. Of 13,453 CS patients, 353 (3%) were in the AF ABL group, 1,701 (12%) in the AF NO ABL group, and 11,399 (85%) in the NO AF group. A total of 7,651 patients (57%) underwent coronary artery bypass grafting, 4,384 (33%) underwent valve surgery, and 1,418 (10%) underwent coronary artery bypass grafting and valve surgery. The overall PPM risk was 1.6% (212 of 13,453); risk was 5.7% (20 of 353) in the AF ABL group, 3.1% (53 of 1,701) in the AF NO ABL group, and 1.2% (139 of 11,399) in the NO AF group. The unadjusted and adjusted odds of PPM were higher in the AF ABL and AF NO ABL groups than in the NO AF group (adjusted odds ratio [OR] 2.7, 95% confidence interval [CI] 1.7 to 4.4, and adjusted OR 1.7, 95% CI 1.2 to 2.4, respectively). The unadjusted OR comparing the AF ABL group and the AF NO ABL group was significant (unadjusted OR 1.9, 95% CI 1.9 to 3.2); however, the OR adjusted for surgery type, age, and gender showed a trend toward significance (adjusted OR 1.6, 95% CI 0.9 to 2.7). In conclusion, in this large cohort of patients who underwent CS, surgical AF ablation appeared to carry an increased risk for postoperative PPM implantation.

Efficiency of different annuloplasty in treating functional tricuspid regurgitation and risk factors for recurrence

BackgroundFunctional tricuspid regurgitation (FTR) is frequent in patients with mitral valve disease. Untreated tricuspid regurgitation (TR) may cause poor clinical outcomes. The surgical factors involved in annuloplasty for FTR remain controversial. Our objective was to compare effectiveness of different tricuspid annuloplasty (TVP), and reveal the risk factors of recurrence. MethodsWe analyzed the clinical details of 399 consecutive patients who underwent mitral surgery with concomitant TVP, from 2006 to 2011, in two Chinese single-centers. Three methods were used for TVP: De Vega surgery was completed in 242 patients; annuloplasty using a flexible band was completed in 98 patients; and surgery with a rigid ring was performed in 59 patients. ResultsThe operative mortality rate was 2.3%. After surgery, the TR grade of all patients decreased significantly. At three years postoperatively, 13.7% of patients were diagnosed with recurrent FTR. At the three year time point, severe TR in the De Vega group was 18%, which was higher than those in the flexible (8.4%) and rigid planner ring groups (5.2%). During follow-up, the recurrent rates in the rigid group were significantly lower than in the flexible group. Multivariate analysis revealed that pre-operative atrial fibrillation, severe TR, large left atrial, ejection fraction (EF)<40%, De Vega annuloplasty, and postoperative permanent pacemaker installation were independent risk factors for severe recurrent TR. ConclusionsRigid ring annuloplasty efficaciously improved post-operative tricuspid valve function in patients with FTR. Atrial fibrillation, a large left atrium, low EF and postoperative permanent pacemaker installation were independent risk factors for severe recurrent TR.

ONE-YEAR FOLLOW-UP OF SUTURELESS AORTIC VALVE REPLACEMENT USING THE PERCEVAL S PROSTHESIS

Sutureless aortic valve replacement (AVR) is an emerging alternative to standard AVR in elderly, high-risk surgical patients. Several published series have demonstrated good perioperative outcomes. However, there is little data in the literature on the durability of this technique and on the clincial follow-up of patients who undergo sutureless AVR. The purpose of this study was to report the one-year clinical and echocardiographic outcomes of patients undergoing sutureless AVR. Between June 2011 and March 2013, 108 consecutive patients underwent sutureless AVR with the Perceval S prosthesis. Patients were followed annually at our institution’s valve clinic. Mean follow-up was 14.1±5.7 months. Mean age was 79.2±4.7 years and 55(51%) patients were female. Mean Logistic EuroSCORE II was 7.0±8.6%. The approach used was a median sternotomy in 74(69%) patients, a ministernotomy in 12(11%) and right anterior parasternal minithoracotomy in 22(20%) patients. Concomitant procedures included CABG in 37 (34%) patients, mitral valve surgery in 9 (8%), septal myectomy in 7 (7%) and tricuspid valve plasty in 3 (3%). Eleven patients (10%) had undergone previous cardiac surgery. Mean aortic cross-clamp time was 40.1±12.3 minutes for isolated AVR and 61.9±21.5 minutes for combined procedures. Operative mortality was 4.6%. Twelve patients (11%) suffered from complete atrioventricular block. Postoperative permanent pacemaker implantation was performed in 23(21%) patients. Mean transaortic gradient was reduced from 45.1±16.6 mmHg preoperatively to 15.0±5.9 mmHg at discharge (p<.001). Indexed aortic effective orifice area was improved from 0.47±0.18 cm2/m2 preoperatively to 0.90±0.21 cm2/m2 at discharge (p<.001). Pre-discharge echocardiographic evaluation showed mild (1/4) paravalvular leak in 14(13%) patients. Among perioperative survivors, one-year survival was 92±3%. No patient underwent reoperation during the follow-up period. At last follow-up, all but one patient were in NYHA class I or II. At a mean echocardiographic follow-up of 14.1±4.6 months, mild (1/4) and moderate (2/4) paravalvular leaks were observed in 2 and 5 patients, respectively. Mean indexed left ventricular mass was 103±27 g/m2 compared to 107±27 g/m2 at baseline (p=.19). Left ventricular mass regression was observed in 57% of patients. Upon univariate analysis, indexed aortic effective orifice area at discharge was a significant predictor of left ventricular mass regression (OR 1.3 [1.0-1.6] per 0.10 cm2/m2; p=.05). Sutureless AVR yields good survival at one year considering the high baseline risk of this population. Paravalvular leak is a marginal occurrence. Left ventricular mass regression seems to be dependent on the complete relief of left ventricular outflow tract obstruction.

Permanent pacemaker requirement after concomitant surgical ablation for atrial fibrillation

In their recent review of ablation options for atrial fibrillation, Pinho-Gomes et al. [1] omitted permanent pacemaker requirement as a complication of surgical ablation. In their series of 594 patients undergoing concomitant surgical ablation of atrial fibrillation, of whom 6.9% required permanent pacemakers postoperatively, Pecha et al. [2] identified biatrial lesion sets as a statistically significant risk factor for permanent pacemaker insertion after surgical ablation, confirming the findings of Soni et al. [3] in their series of 305 patients. We analysed 17 983 patients undergoing valve surgery with concomitant ablation identified from the Nationwide Inpatient Sample between 2002 and 2010. This administrative database is sponsored by the Agency for Healthcare Research and Quality, and contains information on all inpatient episodes in approximately one-fifth of US hospitals selected to provide a representative sample of national practice: the individual hospitals sampled vary each year. Pacemakers were implanted in 6.9% of patients undergoing valve surgery. After adjusting for baseline patient comorbidity, concomitant ablation procedure [odds ratio (OR) 1.31, 95% confidence interval (CI) 1.27–1.41] was one of the main independent predictors of permanent pacemaker implantation in patients undergoing valve surgery. In patients undergoing ablation, valve procedures associated with the greatest risk of permanent pacemaker requirement were mitral replacement (OR 1.37, 95% CI 1.2–1.67) and combined mitral replacement and tricuspid valve surgery (OR 1.79, 95% CI 1.69– 2.77) (isolated aortic valve replacement was used as the reference). Mitral repair was less likely to result in permanent pacemaker (OR 0.84, 95% CI 0.72–0.98), unless concomitant tricuspid surgery was undertaken (OR 1.79, 95% CI 1.37–2.33). These surgical predictors of permanent pacemaker requirement are consistent with data from a previous single-centre series [4], and the overall incidence of pacemaker insertion we observed is similar to that reported in an analysis of the Society of Thoracic Surgeons database [5]. The main limitation of the Nationwide Inpatient Sample in this context is that it does not provide information on the ablation lesion sets employed, or provide sufficient data to adjust for other potential confounding variables. However, this analysis indicates that patients undergoing concomitant surgical ablation at the time of valve surgery have a significantly increased risk of postoperative permanent pacemaker requirement in comparison with those who do not undergo concomitant ablation.

Pacemaker dependency after isolated aortic valve replacement: do conductance disorders recover over time?†

Permanent pacemaker (PPM) implantation is required in 3-8% of all patients undergoing aortic valve replacement (AVR). Our aim was to evaluate long-term PPM dependency and recovery of atrioventricular (AV) conduction disorders during follow-up in these patients. Since January 1997, a total of 2106 consecutive patients underwent isolated AVR at our institution. Of these, 138 patients (6.6%, 72 female, median age 71 (37-89) years) developed significant conduction disorders leading to PPM implantation postoperatively. Preoperative ECG showed normal sinus rhythm (n = 64), first degree AV block (n = 19), left bundle branch block (n = 13), right bundle branch block (n = 16), left anterior hemiblock (n = 14) and AV block with ventricular escape rhythm (n = 10). Atrial fibrillation was present in 23 patients. Pacemakers were implanted after a median of 7 (1-30) days following AVR. PPM dependency was analysed by ECG and pacemaker check during follow-up. A total of 45 of 138 patients with postoperative PPM Implantation died during a mean follow-up time of 5.3 ± 4.7 years. A further 9 patients were lost to follow-up. Long-term survivals at 1, 5 and 10 years were 88%, 79% and 59%, respectively. Only 8 (10%) of 84 survivors were no longer pacemaker-dependent. The majority of patients (n = 66, 79%) required permanent ventricular stimulation, and the remaining 10 (13%) showed intermittent stimulation with a mean ventricular stimulation fraction of 73% (22-98%). The majority of patients do not recover from AV conduction disorders after AVR. Since higher-grade AV blocks expose patients to a high risk of sudden death after surgery, we recommend early implantation of permanent pacemaker.

A Case of Transient Advanced Atrioventricular Block after Aortic Valve Replacement, Report of a Case

Approximately 3%-11.8% of cases require permanent pacemaker implantation due to atrioventricular block (AVB) after aortic valve replacement (AVR), and determination of conduction disturbances such as left or right bundle branch block by preoperative electrocardiography is correlated with high risk postoperative permanent pacemaker implantation. Intraoperative risk factors include severe calcification of the aortic valve, prolonged cardiopulmonary bypass time, aortic clamp time. Recently, there have been reports of high rates of pacemaker implantation (14.2%) after transcatheter aortic valve implantation. The time of permanent pacemaker implantation after AVB is often 4-10 days, and the European Society of Cardiology guidelines recommend a period of seven days of persistent atrioventricular block postsurgery prior to permanent pacemaker implantation. We report a 79-year-old woman in which the patient developed high-degree AVB after AVR was performed for severe aortic stenosis with complete right bundle branch block. However, her pulse returned to sinus rhythm 7 days postsurgery.

Predictors of permanent pacemaker implantation after Medtronic CoreValve bioprosthesis implantation

High-grade conduction disturbances requiring permanent pacemaker (PPM) implantation occur in up to 40% of patients following transcatheter aortic valve implantation (TAVI). The aim of this study was to identify pre-operative risk factors for PPM implantation after TAVI with the Medtronic CoreValve prosthesis (CVP). We retrospectively analysed 109 patients following transfemoral CVP implantation performed between 2008 and 2009 at the Leipzig Heart Center. Patients who had indwelling PPM at the time of TAVI (n = 21) were excluded, leaving 88 patients for analysis. Mean age was 80.3 ± 6.6 years and logistic EuroScore predicted risk of mortality was 23.3 ± 12.1%. A total of 32 patients (36%) underwent PPM implantation post-TAVI during the same hospital admission. A total of 27/88 (31%) had evidence of pre-operative abnormal conduction, including first degree AV block and left bundle brunch block. Statistically significant risk factors for the need for post-operative PPM were patient age >75 years [P = 0.02, odds ratio (OR) 4.6], pre-operative heart rate <65 beats per minute (b.p.m.; P = 0.04, OR 2.9), CVP oversizing >4 mm (P = 0.03, OR 2.8), CVP prosthesis >26 mm (OR 2.2), atrial fibrillation (P = 0.001, OR 5.2), and ventricular rate <65 b.p.m. at the first post-operative day (P = 0.137, OR 6.0). PPM implantation occurs frequently after transfemoral TAVI with the CVP. Older age, chronic atrial fibrillation, pre-operative bradycardia, and larger or significantly oversized prostheses were independent risk factors for PPM implantation following TAVI with the CVP.

Double venous drainage through the superior vena cava in minimally invasive aortic valve replacement: a retrospective study

AimTo compare the outcomes of patients who underwent upper mini-sternotomy or right mini-thoracotomy and those who underwent full sternotomy and to report a technical improvement in venous drainage by means of double venous cannulation of the superior vena cava (SVC) in mini surgical procedures.MethodsWe retrospectively analyzed the outcome of 217 patients who underwent aortic valve replacement through upper mini-sternotomy or right mini-thoracotomy at the Department of Cardiovascular Surgery, University Medical Centre Ljubljana, Slovenia from 1996 till 2010. Cannulation of SVC and right atrial appendage was performed in 142/217 (65%) patients, while in the remaining 75 (35%) patients, double cannulation of SVC was used for venous drainage. The results of patients who underwent mini approaches were compared to 236 patients who underwent full sternotomy for the same purpose from 2009 to 2010 at the same center.ResultsWe found a shorter mean length of intensive care unit stay, less volume chest-tube drainage, shorter crossclamp and cardio pulmonary bypass times, and less postoperative permanent pacemaker implantations in the minimally invasive group patients than in full sternotomy group patients. Using double cannulation of the SVC for venous drainage made venous cannulation in mini approaches easier and eliminated the need for obtaining femoral venous access.ConclusionOur study confirmed that even though technically challenging, upper mini-sternotomy and right mini-thoracotomy approaches for aortic valve replacement have potential advantages over conventional median sternotomy. They were proved to be safe, efficacious, and can significantly reduce surgical trauma and are therefore particularly valuable in some higher risk, obese, diabetic and elderly patients. Using double cannulation of SVC for venous drainage made venous cannulation easier and eliminated the need for obtaining femoral venous access.

Permanent pacemaker implantation rate after transapical transcatheter aortic valve replacement with a balloon-expandable prosthesis is low and has no impact on follow-up mortality

Objectives: Rate and determinants of postoperative permanent pacemaker implantation (PPMI) after transcatheter aortic valve implantation (TAVI) have been investigated in small cohorts of patients treated using different approaches (transfemoral and transapical) and different prostheses (Medtronic CoreValve and Edwards SAPIEN valve). The aim of this single institution study was to determine the incidence of PPMI in a large cohort of patients undergoing transapical TAVI using a balloon-expandable prosthesis (Edwards SAPIEN THV, Edwards Lifesciences, Irvine, CA).

Incidence rate and predictors of permanent pacemaker implantation after transcatheter aortic valve implantation with self-expanding CoreValve prosthesis

Conduction disorders and permanent pacemaker (PPM) implantation are common complications in patients undergoing transcatheter aortic valve implantation (TAVI). Previous studies, evaluating small populations, have identified several different predictors of PPM implantation after TAVI. The aim of this study was to assess the incidence rate of conduction disorders and the predictors of postoperative PPM requirement in a large series of patients undergoing TAVI. Data were analyzed from 181 consecutive patients at high-risk surgery who underwent TAVI at our institute between July 2007 and April 2011. All patients underwent implantation of the third-generation percutaneous self-expanding CoreValve® prosthesis (CoreValve, Inc., Irvine, CA, USA). In all patients, a 12-lead electrocardiogram and a 24-h holter monitoring was recorded before and after the procedure in order to assess the presence of conduction disorders. Clinical data, preoperative conduction disorders, echocardiographic patterns, and procedural data were tested as predictors of PPM implantation after TAVI. Left bundle branch block (LBBB) was the most common conduction disorder, with an incidence of 50.3% at discharge. Fifty-two (32.1%) patients developed a persistent complete AVB requiring PPM implantation. PPM implantation was strongly correlated with the presence of preoperative right bundle branch block (RBBB) which was found to be the only independent predictor of PPM implantation (HR 16.5, CI 3.3-82.3, p < 0.001). LBBB and PPM implantation requirement after TAVI are common occurrences using the self-expanding CoreValve prosthesis. In this large series of consecutive patients, only RBBB was found to be a strong predictor of PPM requirement.

583 Cost Impact of Permanent Pacemaker Insertion in Orthotopic Heart Transplant Recipients: A Comparison of Bi-Atrial and Bi-Caval Techniques

Bi-atrial and bi-caval anastomotic techniques have been compared in heart transplant populations and their respective rates of postoperative permanent pacemaker (PPM) placement described. Previous studies suggest that the rate of PPM placement is higher with the bi-atrial technique because of postoperative atrial distortion. The aim of this study is to confirm this finding among our patient population - now just over 700 since the program's inception - and, further, to analyze the cost impact of these two techniques in relation to their rates of PPM placement.

Postoperative permanent pacemaker implantation in patients undergoing trans-catheter aortic valve implantation: what is the incidence and are there any predicting factors?

A best evidence topic was written according to a structured protocol. The issue was to determine the incidence and predictors of postoperative permanent pacemaker (PPM) implantation in patients undergoing trans-catheter aortic valve implantation (TAVI) for symptomatic calcific aortic stenosis and to compare this to the known risks of this complication following surgical aortic valve replacement (AVR). Using the reported search method 3071 articles were identified, of which 94 were relevant to the procedure of TAVI and 14 were deemed to represent the best evidence. All 14 studies, including both multi-centre registries and single-centre retrospective case series containing ≥30 patients, reported incidence of postoperative PPM implantation. Five of these studies also assessed predictors of the need for postoperative PPM implantation. The author, journal, date and country of publication, study type, level of evidence, patient group, outcomes and results were tabulated for these studies. We conclude that the current best available evidence suggests that the mean incidence of PPM implantation following TAVI is 14.2% (range 0-34%, median 9.7%), although this appears higher with the CoreValve prosthesis (five studies, mean 20.8%, range 9.3-30.0%) than with the Edwards-Sapien prosthesis (six studies, mean 5.4%, range 0-10.1%). The mean incidences of PPM implantation overall and when using the CoreValve prosthesis are higher than the mean incidence of 7.0% (range 3-11.8%, median 7.2%) following conventional AVR and may be explained by distinct differences between the patient groups involved and the procedure performed. Indications for PPM implantation appear to occur early in the postoperative period following TAVI and there is little evidence of recovery following atrioventricular block (AVB). New onset persistent left bundle branch block is common following TAVI but the significance and follow-up required is unclear. Independent predictors of PPM requirement following TAVI include use of the CoreValve prosthesis and evidence of conduction system dysfunction, either pre-existing right bundle branch block or AVB at the time of TAVI. All patients should be made aware of the high risk of PPM implantation with TAVI.

Standard versus bicaval techniques for orthotopic heart transplantation: An analysis of the United Network for Organ Sharing database

Most studies of anastomotic technique have been underpowered to detect subtle differences in survival. We analyzed the United Network for Organ Sharing database for trends in use and outcomes after either bicaval or traditional (biatrial) anastomoses for heart implantation. Review of United Network for Organ Sharing data identified 20,999 recipients of heart transplants from 1997 to 2007. Patients were stratified based on the technique of atrial anastomosis: standard biatrial (atrial group, n = 11,919, 59.3%), bicaval (caval group, n = 7661, 38.1%), or total orthotopic (total group, n = 519, 2.6%). The use of the bicaval anastomosis is increasing, but many transplantations continue to use a biatrial anastomosis (1997, 0.2% vs 97.6%; 2007, 62.0% vs 34.7%; P < .0001). Atrial group patients required permanent pacemaker implantation more often (odds ratio, 2.6; 95% confidence interval, 2.2-3.1). Caval group patients had a significant advantage in 30-day mortality (odds ratio, 0.83; 95% confidence interval, 0.75-0.93), and Cox regression analysis confirmed the decreased long-term survival in the atrial group (hazard ratio, 1.11; 95% confidence interval, 1.04-1.19). Heart transplantations performed with bicaval anastomoses require postoperative permanent pacemaker implantation at lower frequency and have a small but significant survival advantage compared with biatrial anastomoses. We recommend that except where technical considerations require a biatrial technique, bicaval anastomoses should be performed for heart transplantation.

CARDIAC RHYTHM AND ATRIAL TRANSPORT FUNCTION AFTER SURGICAL ABLATION OF ATRIAL FIBRILLATION USING CRYOENERGY: PREDICTORS AND EFFECTIVENESS OF THE PROCEDURE

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. 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. 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. 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.

Permanent pacemaker implantation after isolated aortic valve replacement: incidence, risk factors and surgical technical aspects

Conducting system defects are common in patients with aortic valve disease. Aortic valve replacement may result in further conduction abnormalities requiring permanent pacemaker implantation. The aim of our study was to identify the incidence and predictors for postoperative 30-day permanent pacemaker implantation in patients undergoing isolated aortic valve replacement, and the effect of an accurate surgical technique in order to prevent permanent pacemaker implantation. Data from 261 consecutive patients (mean age 69 +/- 12 years, 136 men) undergoing isolated aortic valve replacement from January 2004 to January 2008 were analyzed retrospectively. Indications for aortic valve replacement were aortic valve stenosis (n = 156), stenoinsufficiency (n = 63), regurgitation (n = 42). Aortic bicuspid valve was present in 25% of cases (n = 64), redo operation was the indication in 7% (n = 18). Preoperative conducting system disease, defined as first-degree atrioventricular block, left or right bundle-branch block or left anterior hemiblock, was present in 25.6% (n = 67) of patients. An accurate surgical technique for debridement of calcific material was performed. In-hospital mortality was 0.8% (2 out of 261 patients). Postoperatively, 8 out of 261 patients (3%) required permanent pacemaker implantation, for second-degree (n = 1) or complete atrioventricular block (n = 7). Incidence of permanent pacemaker implantation was similar for patients either with or without preoperative conducting system disease (25 vs. 25.7%, P = NS). Independent predictors of permanent pacemaker implantation were greater preoperative end-systolic diameter (P = 0.026) and left ventricular septum hypertrophy (P = 0.041). Need of permanent pacemaker implantation after aortic valve replacement seems to be related more to preoperative advanced aortic valve disease rather than pre-existing conducting system abnormalities. An accurate surgical technique for aortic valve replacement probably helps to prevent further impairment of conducting system function requiring early postoperative permanent pacemaker implantation.