Incidence Of Pacemaker Implantation Research Articles

Emergency interventional treatment of cardiogenic shock due to decompensated aortic stenosis: a systematic review and meta-analysis

Abstract Introduction Cardiogenic shock (CS) induced by severe aortic stenosis (AS) represents a critical condition with a high mortality rate. Its optimal treatment is still unclear due to the recent advances in interventions and supportive therapies. Emergency transcatheter aortic valve implantation (eTAVI) as definitive therapy and emergency balloon aortic valvuloplasty (eBAV) as bridge to intervention are viable therapeutic options, but it is still unclear which strategy provides the best outcomes. Purpose/Objective This meta-analysis aimed to investigate the effectiveness and safety of eTAVI versus eBAV in patients with cardiogenic shock due to severe aortic stenosis. The primary endpoint was mortality at 30-day. Secondary outcomes were 1-year mortality and vascular and bleeding complications as well as incidence of pacemaker implantation. Methods We performed a systematic literature review to identify relevant studies reporting outcomes of patients undergoing eBAV or eTAVI due to CS. Studies conducting eTAVI or eBAV in patients with cardiogenic shock due to severe aortic stenosis were included. Data extraction and analysis were performed to evaluate mortality rates at 30 days and 1 year, as well as secondary endpoints including procedural complications. Results 15 studies were included in the meta-analysis (6 for eTAVI, 10 for eBAV, one study comparing the two strategies) with a total of 2702 patients. The pooled estimated rate for mortality at 30 days was 19% (I²= 11.4%; CI 0.16, 0.22) for eTAVI and 40% (I²= 56%; CI 0.31, 0.49) for eBAV while the pooled estimated rate for mortality at one year were 66% (I²= 27.1%; CI 0.57, 0.75) and 45% (I²= 82.8%; CI 0.21, 0.69) for eBAV and eTAVI respectively. Pooled estimated rate for any bleeding was 11% (I²= 54.3%; CI 0.02, 0.21) for eBAV and 11% (I²= 88.3%; CI 0.02, 0.20) for eTAVI, while for major vascular complications were 6% (I²= 72.7%; CI 0.00, 0.13) and 7% (I²= 52.1%; CI 0.03, 0.11) for eBAV and eTAVI respectively. As expected, pooled estimates for pacemaker implantation was high for eTAVI 9 %(I²= 0%; CI 0.08, 0.10) while 1% (I²= 9.5%;CI 0.0, 0.05) for eBAV. Conclusion Using the totality of existing evidence, this study synthesizes the current evidence to elucidate the benefits and risks associated with eTAVI and eBAV in patients with CS due to AS. eTAVI procedure has beneficial survival rates, while it is associated with higher pacemaker implantations. While these findings are hypothesis generating only, as selection bias and other confounders cannot be excluded, they provide valuable insights to guide clinical decision-making in CS patients.30-day mortality

Predictors of pacemaker implantation within three months after catheter ablation of atrial fibrillation.

It is inevitable for patients to have a temporary or permanent pacemaker implanted during or after radiofrequency catheter ablation (RFCA) for treatment of atrial fibrillation (AF) in some cases. The aim of our study was to evaluate the incidence of pacemaker implantation (PMI) during or within 3 months of RFCA for AF and to identify the risk factors that were associated with PMI. We performed a retrospective analysis of consecutive AF patients who underwent RFCA between August 2018 and October 2020 at our center. The incidence of PMI within 3 months during or after RFCA were assessed. A multivariate logistic regression model was performed to identify predictors of PMI. One thousand and five patients (mean age, 60.2±10.3 years; 37.6% women) were included in this analysis. PVI was performed in all patients. A total of 23 (2.3%) patients had a pacemaker implanted within 3 months during or after ablation. Multivariable logistic regression analysis revealed that older age (OR: 1.08 [95% CI 1.03-1.13], p=.003), female sex (OR: 3.08 [95% CI 1.28-7.45], p=.012), paroxysmal AF (OR: 4.71 [95% CI 1.09-20.45], p=.038) and repeated ablation (OR: 2.78 [95% CI 1.04-7.40], p=.041) were the independent predictors for PMI. Older age, female sex, paroxysmal AF and repeated ablation were identified as predictive risk factors for PMI after RFCA in patients with AF. A "watch and wait" strategy could be taken for patients with temporary PMI after ablation, especially for those with prolonged sinus pause after AF termination.

Interventional versus Surgical Treatment of Degenerated Freestyle Prosthesis.

Bioprosthetic stentless aortic valves may degenerate over time and will require replacement. This study aimed to evaluate early- and mid-term outcomes after isolated surgical redo aortic valve replacement (redo-SAVR) and transcatheter valve-in-valve implantation (TAVI-VIV) for degenerated stentless Freestyle bioprostheses. We reviewed records of 56 patients at a single center. Overall, 37 patients (66.1%) received TAVI-VIV and 19 (33.9%) received redo-SAVR. Thirty-day survival was similar in both groups (100%). One-year survival was comparable between groups (97.3% in TAVI-VIV and 100% in redo-SAVR, p = 1.0). The difference in mid-term survival after adjusting for age and EuroScore II was not significant (p = 0.41). The incidence of pacemaker implantation after TAVI-VIV was higher than after redo-SAVR (19.4% vs. 0%, p = 0.08). The 30-day and 1-year survival rates after both procedures were outstanding, irrespective of baseline characteristics. Isolated redo-SAVR should be favored in young patients, as the pacemaker implantation rate is lower. TAVI-VIV for degenerated Freestyle prosthesis can be a method of choice in elderly patients and those with high operative risk.

Incidence and risk factors for pacemaker implantation in light chain and transthyretin cardiac amyloidosis

Abstract Background The incidence and risk factors of pacemaker (PM) implantation in patients with cardiac amyloidosis (CA) are largely unexplored. Purpose We sought to characterise the trends in the incidence of permanent PM and to identify baseline predictors of future PM implantation in light chain (AL) and transthyretin (ATTR) CA. Methods Multicentre, retrospective, observational study. Consecutive patients with AL and ATTR-CA diagnosed or referred at participating Centres between 2017 and 2020 were included. Clinical data recorded within ± 1 month from baseline evaluation were collected from electronic medical records. The primary outcome of the study was the need for clinically-indicated PM implantation. Reversible causes of conduction system disease were systematically ruled out before PM implantation. Patients with PM (n=41) and/or permanent defibrillator in situ (n=13) at the time of CA diagnosis were excluded. Results The study population consisted of 405 patients: 29.4% AL, 14.6% variant ATTR and 56% wild-type ATTR; 82.5% were males, with median age 76 years. During a median follow-up of 33 months (interquartile range 21–46), 36 (8.9%) patients experienced the primary outcome: 10 patients with AL-CA, 2 with variant ATTR-CA and 24 with wild-type ATTR-CA (p=0.08). At multivariable analysis, history of atrial fibrillation (hazard ratio [HR] 3.80, p=0.002), PR interval (HR 1.013, p=0.002) and QRS >120 ms (HR 4.7, p=0.001) on baseline ECG were independently associated with PM implantation (Figure 1). In the individual patient, the contemporary presence of these 3 factors yielded the highest risk of PM implantation (HR 6.26, p=0.003). Conclusion In a large cohort of AL and ATTR-CA, the incidence of PM implantation was high accounting for ≈9% of patients in the 3 years following the diagnosis. History of atrial fibrillation, longer PR interval and QRS >120 ms identified CA patients at high-risk of future PM implantation (Figure 2). CA patients with these features might need close monitoring during follow-up for the development of conduction system disease requiring PM implantation. Funding Acknowledgement Type of funding sources: None.

Incidence of and risk factors for pacemaker implantation after the modified Cryo-Maze procedure for atrial fibrillation

ObjectivesThe Maze procedure is a well-established treatment for atrial fibrillation. However, it is sometimes associated with bradycardia requiring pacemaker implantation. We assessed the rates of in-hospital and late-onset pacemaker implantation after the modified Cryo-Maze procedure and explored the risk factors for pacemaker implantation. MethodsThis study enrolled a series of 751 patients who underwent the modified Cryo-Maze procedure at our institution between 2001 and 2020. Multivariable Fine-Gray regression was used to analyze the risk factors for late-onset pacemaker implantation. ResultsTwelve patients (1.6%) underwent in-hospital pacemaker implantation, and 55 patients (7.3%) underwent late-onset pacemaker implantation during a median follow-up of 4.5 years (interquartile range, 1.4-10.0). The most common primary indication for pacemaker implantation was sick sinus syndrome (56 patients [7.5%]), followed by complete atrioventricular block (11 patients [1.5%]). The cumulative incidence of late-onset pacemaker implantation with death as a competing risk was 2.8% at 1 year, 7.7% at 5 years, and 10.8% at 10 years. Risk factors for late-onset pacemaker implantation included a longer preoperative atrial fibrillation duration (hazard ratio, 1.14; P < .001) and an older age (hazard ratio, 1.05; P = .001). The mortality, cumulative incidence of cerebrovascular accidents, and rate of atrial fibrillation recurrence were not significantly different between patients with and without pacemaker implantation. ConclusionsLonger preoperative atrial fibrillation duration and older age are risk factors for late-onset pacemaker implantation after the modified Cryo-Maze procedure. However, the incidence of pacemaker implantation is not associated with increased morbidity or atrial fibrillation recurrence.

Early and Midterm Clinical Outcomes of Transcatheter Valve-in-Valve Implantation Versus Redo Surgical Aortic Valve Replacement for Aortic Bioprosthetic Valve Degeneration: Two Faces of the Same Medal

To compare early and midterm outcomes of transcatheter valve-in-valve implantation (ViV-TAVI) and redo surgical aortic valve replacement (re-SAVR) for aortic bioprosthetic valve degeneration. Patients who underwent ViV-TAVI and re-SAVR for aortic bioprosthetic valve degeneration between January 2010 and October 2018 were retrospectively analyzed. Mean follow-up was 3.0 years. In-hospital, early, and mid-term outcomes. Eighty-eight patients were included in the analysis. Thirty-one patients (37.3%) had ViV-TAVI, and 57 patients (62.7%) had re-SAVR. In the ViV-TAVI group, patients were older (79.1 ± 7.4 v 67.2 ± 14.1, p < 0.01). The total operative time, intubation time, intensive care unit length of stay, total hospital length of stay, inotropes infusion, intubation >24 hours, total amount of chest tube losses, red blood cell transfusions, plasma transfusions, and reoperation for bleeding were significantly higher in the re-SAVR cohort (p < 0.01). There was no difference regarding in-hospital permanent pacemaker implantation (ViV-TAVI=3.2% v re-SAVR=8.8%, p=0.27), patient-prosthesis mismatch (ViV-TAVI=12 patients [mean 0.53 ± 0.07] and re-SAVR=ten patients [mean 0.56 ± 0.08], p=0.4), stroke (ViV-TAVI=3.2% v re-SAVR=7%, p=0.43), acute kidney injury (ViV-TAVI=9.7% v re-SAVR=15.8%, p=0.1), and all-cause infections (ViV-TAVI=0% v re-SAVR=8.8%, p=0.02), between the two groups. In-hospital mortality was 0% and 7% for ViV-TAVI and re-SAVR, respectively (p=0.08). At three-years' follow-up, the incidence of pacemaker implantation was higher in the re-SAVR group (ViV-TAVI=0 v re-SAVR=13.4%, p < 0.01). There were no differences in reintervention (ViV-TAVI=3.8% v re-SAVR=0%, p=0.32) and survival (ViV-TAVI=83.9% v re-SAVR=93%, p=0.10) between the two cohorts. ViV-TAVI is a safe, feasible, and reliable procedure.

Pacemaker need after sutureless aortic valve replacement: the role of the learning curve.

Aortic valve replacement (AVR) using sutureless prosthesis is a reasonable alternative in those patients with aortic stenosis who would benefit from reduced cross clamp time, such as elderly and high-risk patients. Actually, excellent performances have been demonstrated in hemodynamic outcomes and safety, but some questions remain open regarding long-term durability and the need for postoperative pacemaker implantation. Between January 2014 and August 2019, all 436 patients [male 40.6%, median age 78 years interquartile range (73-82)] treated with sutureless AVR with a Perceval prosthesis were included in our analysis. The univariate logistic regression showed previous aortic valve surgery [P = 0.028; odds ratio (OR) 3.248], dialysis (P = 0.036; OR 6.435), renal insufficiency (P = 0.021; OR 2.75), EuroSCORE II (P = 0.016; OR 1.051) and year of operation (P < 0.01; OR 0.658) as factors associated with the development of atrioventricular type II or type III block or junctional block requiring pacemaker implantation. The overall incidence of pacemaker implantation after sutureless AVR was 7.1% in the current study, but it dropped to 3.8 and 4.7%, respectively, in 2018 and 2019. The Perceval aortic valve is associated with encouraging postoperative results. The incidence of pacemaker implantation is strictly linked to the surgeons' experience, decreasing year by year after an adequate sizing, reaching a percentage comparable with sutured valve.

Immediate and long-term need for permanent cardiac pacing following aortic valve replacement

Introduction: Atrioventricular (AV) node conduction disturbances are common following surgical aortic valve replacement (SAVR), and in some cases the patient needs a permanent pacemaker (PPM) implantation before discharge from hospital. Little is known about the long-term need for PPM and the PPM dependency of these individuals. We determined the incidence of PPM implantation before and after discharge in SAVR patients. Methods: We studied 557 consecutive patients who underwent SAVR for aortic stenosis in Iceland between 2002 and 2016. Timing and indication for PPM were registered, with a new concept, ventricular pacing proportion (VPP), defined as ventricular pacing ≥90% of the time, being used to approximate pacemaker dependency. The median follow-up time was 73 months. We plotted the cumulative incidence of pacemaker implantation, treating death as a competing risk. Results: Of the 557 patients, 22 (3.9%) received PPM in the first 30 days after surgery, most commonly for complete AV block (n = 14) or symptomatic bradycardia (n = 8); Thirty-eight other patients (6.8%) had a PPM implanted >30 days postoperatively, at a median of 43 months after surgery (range 0‒181), most often for AV block (n = 13) or sick-sinus syndrome (n = 10). The cumulative incidence of PPM implantation at 1, 5, and 10 years postoperatively was 5.0%, 9.2%, and 12.3%, respectively. During follow-up, 45.0% of the 60 patients had VPP ≥90%. Conclusion: The cumulative incidence of permanent pacemaker implantation following SAVR was about 12% at 10 years, with every other patient having VPP ≥90% during follow-up. This suggests that AV node conduction disturbances extend significantly beyond the perioperative period.

P1259Right atrial low voltage zone as a novel predictor of sinus node dysfunction in patients with non-paroxysmal atrial fibrillation

Abstract Background Although sinus node dysfunction (SND) coexists with atrial fibrillation (AF) in some cases, SND in patients with Non-paroxysmal AF (Non-PAF) could not be estimated in conventional electrophysiological study. Atrial low voltage zone (LVZ), which may be surrogate for atrial fibrosis, is although reported to present in patients with Non-PAF, the association between SND and right atrial LVZ (RA-LVZ) has not been fully evaluated. The aim of the present study was to assess the relationship between SND and RA-LVZ in patients with Non-PAF. Method Eighty-six Non-PAF patients underwent high density voltage mapping of right atrium (RA) during AF before ablation procedure. We defined LVZ as that with electrogram amplitude &lt;0.1 mV in order to delineate strongly damaged area in RA. We evaluated the surface are of the RA-LVZ in Non-PAF patients with and without SND. Results Twenty-seven of 86 patients (31.4%) presented with SND after AF termination. There were no significant differences between patients with and without SND in variables such as age, sex, AF duration, left atrial diameter, and left ventricular ejection fraction. The mean value of RA-LVZ of all the patients was 12.1±11.4%, and RA-LVZ was significantly larger in patients with SND than in those without SND (22.8±14.6 vs 7.2±4.2%; P&lt;0.001). In multivariate logistic regression analysis for the incidence of subsequent pacemaker implantation (PMI), only RA-LVZ was a significant predictor of subsequent PMI (odd ratio 1.306; 95% confidence interval 1.159 - 1.473; P&lt;0.001). Receiving-operating characteristic curve for PMI following ablation procedure indicated cut-off value 10.5% for RA-LVZ with 85.2% sensitivity and 88.1% specificity (area under curve = 0.924, P&lt;0.001). Kaplan-Meier analysis of the incidence of PMI after AF termination showed that freedom from pacemaker implantation was significantly better in patients with RA-LVA &lt;10.5% than in those with RA-LVZ ≥10.5% (log-rank test; P&lt;0.001). Conclusions Broad RA-LVZ measured during AF was strongly associated with SND and PMI after AF termination in patients with Non-PAF. Evaluation of RA-LVZ during AF could be a potential target in predicting SND requiring PMI in patients with Non-PAF.

Electrocardiographic and clinical predictors of permanent pacemaker insertion following Perceval sutureless aortic valve implantation

BackgroundSutureless aortic valve replacement surgery (AVR) is a reasonable alternative surgical approach in those patients with aortic stenosis who would benefit from reduced cross clamp time, such as elderly and high-risk patients. We sought to evaluate the incidence of pacemaker (PM) implantation following sutureless AVR and to analyse possible pre-operative electrocardiographic and clinical predictors of PM implantation. Methods and resultsBetween November 2013 and March 2015, 58 patients (male 43%, age 77.9 ± 4.9 years) having undergone sutureless AVR with a Perceval prosthesis (Sorin Biomedica Cardio Srl, Saluggia, Italy) were taken into consideration for our analysis. During a mean follow up of 13.8 ± 5.0 months (median 13 months), 14 patients (24.1%) underwent pacemaker (PM) implantation following sutureless AVR procedure. Among these patients, 12 (86%) presented III degree atrioventricular (AV) block, 1 (7%) presented II degree AV block, and remaining one (7%) severe symptomatic bradycardia. The comparison of pre-operative characteristics between PM group and no PM group highlighted that QRS duration, EuroSCORE II index and chronic renal dysfunction were significantly associated with the development of AV conduction abnormalities/symptomatic bradycardia requiring PM implantation (respectively, p = 0.01, p = 0.02 and p = 0.03). ConclusionsThe incidence of PM implantation after sutureless AVR was 24.1% in the present study. The EuroSCORE II, QRS duration and renal dysfunction were significantly associated with higher risk of AV conduction abnormalities/symptomatic bradycardia requiring PM placement.

Rapid Deployment Versus Conventional Bioprosthetic Valve Replacement for Aortic Stenosis

BackgroundSurgical aortic valve replacement using conventional biological valves (CBVs) is the standard of care for treatment of old patients with aortic valve disease. Recently, rapid deployment valves (RDVs) have been introduced. ObjectivesThe purpose of this study was to report the nationwide German experience concerning RDVs for treatment of aortic valve stenosis and provide a head-to-head comparison with CBVs. MethodsA total of 22,062 patients who underwent isolated surgical aortic valve replacement using CBV or RDV between 2011 and 2015 were enrolled into the German Aortic Valve Registry. Baseline, procedural, and in-hospital outcome parameters were analyzed for CBVs and RDVs using 1:1 propensity score matching. Furthermore, 3 RDVs were compared with each other. ResultsA total of 20,937 patients received a CBV, whereas 1,125 patients were treated with an RDV. Patients treated with an RDV presented with significantly reduced procedure (160 min [25th to 75th percentile: 135 to 195 min] vs. 150 min [25th to 75th percentile: 127 to 179 min]; p < 0.001), cardiopulmonary bypass (83 min [25th to 75th percentile: 68 to 104 min] vs. 70 min [25th to 75th percentile: 56 to 87 min]; p < 0.001), and aortic cross clamp times (60 min [25th to 75th percentile: 48 to 75 min] vs. 44 min [25th to 75th percentile: 35 to 57 min]; p < 0.001), but showed significantly elevated rates of pacemaker implantation (3.7% vs. 8.8%; p < 0.001) and disabling stroke (0.9% vs. 2.2%; p < 0.001), whereas in-hospital mortality was similar (1.7% vs. 2.2%; p = 0.22). These findings persisted after 1:1 propensity score matching. Comparison of the 3 RDVs revealed statistically nonsignificant different pacemaker rates and significantly different post-operative transvalvular gradients. ConclusionsIn this large, all-comers database, the incidence of pacemaker implantation and disabling stroke was higher with RDVs, whereas no beneficial effect on in-hospital mortality was seen. The 3 RDVs presented different complication profiles with regard to pacemaker implantation and transvalvular gradients. (German Aortic Valve Registry [GARY]; NCT01165827)

Sutureless Perceval Aortic Valve Versus Conventional Stented Bioprostheses: Meta-Analysis of Postoperative and Midterm Results in Isolated Aortic Valve Replacement.

BackgroundAortic stenosis is the most common valvular disease and has a dismal prognosis without surgical treatment. The aim of this meta‐analysis was to quantitatively assess the comparative effectiveness of the Perceval (LivaNova) valve versus conventional aortic bioprostheses.Methods and ResultsA total of 6 comparative studies were identified, including 639 and 760 patients who underwent, respectively, aortic valve replacement with the Perceval sutureless valve (P group) and with a conventional bioprosthesis (C group). Aortic cross‐clamping and cardiopulmonary bypass duration were significantly lower in the P group. No difference in postoperative mortality was shown for the P and C groups (2.8% versus 2.7%, respectively; odds ratio [OR]: 0.99 [95% confidence interval (CI), 0.52–1.88]; P=0.98). Incidence of postoperative renal failure was lower in the P group compared with the C group (2.7% versus 5.5%; OR: 0.45 [95% CI, 0.25–0.80]; P=0.007). Incidence of stroke (2.3% versus 1.7%; OR: 1.34 [95% CI, 0.56–3.21]; P=0.51) and paravalvular leak (3.1% versus 1.6%; OR: 2.52 [95% CI, 0.60–1.06]; P=0.21) was similar, whereas P group patients received fewer blood transfusions than C group patients (1.16±1.2 versus 2.13±2.2; mean difference: 0.99 [95% CI, −1.22 to −0.75]; P=0.001). The incidence of pacemaker implantation was higher in the P than the C group (7.9% versus 3.1%; OR: 2.45 [95% CI, 1.44–4.17]; P=0.001), whereas hemodynamic Perceval performance was better (transvalvular gradient 23.42±1.73 versus 22.8±1.86; mean difference: 0.90 [95% CI, 0.62–1.18]; P=0.001), even during follow‐up (10.98±5.7 versus 13.06±6.2; mean difference: −2.08 [95% CI, −3.96 to −0.21]; P=0.030). We found no difference in 1‐year mortality.ConclusionsThe Perceval bioprosthesis improves the postoperative course compared with conventional bioprostheses and is an option for high‐risk patients.

Pacemaker Use Following Heart Transplantation.

The incidence of permanent pacemaker implantation after orthotopic heart transplantation has been reported to be 2%-24%. Transplanted hearts usually exhibit sinus rhythm in the operating room following reperfusion, and most patients do not exhibit significant arrhythmias during the postoperative period. However, among the patients who do exhibit abnormalities, pacemakers may be implanted for early sinus node dysfunction but are rarely used after 6 months. Permanent pacing is often required for atrioventricular block. A different cohort of transplant patients presents later with bradycardia requiring pacemaker implantation, reported to occur in approximately 1.5% of patients. The objectives of this study were to investigate the indications for pacemaker implantation, compare the need for pacemakers following bicaval vs biatrial anastomosis, and examine the long-term outcomes of heart transplant patients who received pacemakers. For this retrospective, case-cohort, single-institution study, patients were identified from clinical research and administrative transplant databases. Information was supplemented with review of the medical records. Standard statistical techniques were used, with chi-square testing for categorical variables and the 2-tailed t test for continuous variables. Survival was compared with the use of log-rank methods. Between January 1968 and February 2008, 1,450 heart transplants were performed at Stanford University. Eighty-four patients (5.8%) were identified as having had a pacemaker implanted. Of these patients, 65.5% (55) had the device implanted within 30 days of transplantation, and 34.5% (29) had late implantation. The mean survival of patients who had an early pacemaker implant was 6.4 years compared to 7.7 years for those with a late pacemaker implant (P<0.05). Sinus node dysfunction and heart block were the most common indications for pacemaker implantation. Starting in 1997, a bicaval technique was used for implantation. The incidence of pacemaker implantation by technique was 2.0% for bicaval and 9.1% for biatrial (P=0.001). Significantly more rejection episodes occurred in the pacemaker group (2.67 ± 2.18) compared with the no-pacemaker group (2.01 ± 2.05) (P<0.05). Our results show a decreased pacemaker need after bicaval anastomosis and that more patients who needed a pacemaker after transplantation had a pretransplant diagnosis of ischemic cardiomyopathy. In our cohort, the need for a permanent pacemaker was also associated with older donor grafts and an increase in the number of treated rejection episodes.

A single center's experience with pacemaker implantation after the Cox maze procedure for atrial fibrillation

ObjectiveThe Cox maze procedure (CM) is safe and effective for all atrial fibrillation (AF) types. A recent randomized trial found alarming rates of pacemaker implantation (PMI) during hospitalization after CM. The purpose of this study was to assess the rate of PMI and its impact on outcomes after CM. MethodsIncidence of PMI was captured for all CM patients (2005-2015; N = 739). Data were collected prospectively. Multivariable logistic regression was conducted to determine risk factors for PMI. Propensity score matching was conducted between concomitant CM patients and patients without surgical ablation since 2011. ResultsFifty-two patients (7.0%) had in-hospital PMI after CM. Most common primary indication for PMI was sick sinus syndrome (67%), followed by complete heart block (23%) and sinus bradycardia (10%). The only risk factor for in-hospital PMI was type of procedure (P = .020). Patients with multiple valve procedures were at greatest risk (P = .004-.035). STS-defined perioperative outcomes were similar for patients with and without in-hospital PMI. Sinus rhythm off antiarrhythmic drugs were similar by PMI. After propensity score matching (n = 180 per group), in-hospital PMI was similar in CM patients and those without surgical ablation (5% vs 4%, P = .609). ConclusionsThis study demonstrated lower incidence of PMI after CM procedures than recently reported. When indicated, PMI was not associated with increased short- or long-term morbidity or inferior freedom from atrial arrhythmia. Efforts to increase surgeon training with the CM procedure and postoperative management awareness are warranted to improve rhythm outcome and minimize adverse events and PMI.

22 Incidence and predictors of permanent pacemaker insertion after perceval sutureless aortic valve implantation – a retrospective single-centre study

Background Sutureless aortic valve replacement surgery (SAVR) is considered in patients with aortic stenosis who would benefit from reduced cross clamp time, such as elderly and high-risk patients. It serves as an alternative surgical approach to standard surgical AVR and TAVI (Figure 1). Objective The purpose of this study was to evaluate the incidence of PM implantation following sutureless aortic valve replacement using the Perceval S bioprosthesis (Sorin Group, Saluggia, Italy). In addition we sought to evaluate whether there were any pre-operative predictive indicators to identify those patients at higher risk of PM implantation using this technique. Methods During the study period a total amount of 58 consecutive patients (male 43%, age 77.9 ± 4.9 years) with severe aortic stenosis having undergone SAVR were included. Twenty-eight patients (48%) underwent an isolated AVR procedure; in the rest of study population AVR was performed in combination with coronary artery bypass graft (CABG) in 26 patients (45%), surgical pulmonary vein isolation in 2 (3%), tricuspid valve replacement (TVR) in 1 (2%) and both TVR and mitral valve replacement (MVR) in 1 (2%). Full median sternotomy was performed in all patients. Results During a mean follow up of 13.8 ± 5.0 months (median 13 months), 14 patients (24.1%) underwent dual-chamber pacemaker (PM) implantation after the SAVR procedure. The mean time to PM implantation was 5.4 ± 3.6 days (median 5 days). Ten out of 14 (71%) were found completely PM-dependent after PM implantation. The comparison of pre-operative characteristics between PM group and no PM group highlighted that QRS duration, EuroSCORE II index and chronic renal dysfunction were significantly associated with postoperative PM implantation (respectively, p = 0.01, p = 0.02 and p = 0.03). Conclusions In conclusion, we have found that chronic renal disease and QRSd are significant predictors of PM insertion post-Perceval SAVR.

Abstract 429: MicroRNA Control of the Pacemaker Channel and Training-induced Bradycardia

Background: Athletes are prone to bradyarrythmias and have a higher-than-normal incidence of pacemaker implantation but the underlying mechanisms are poorly understood. In previous work we demonstrated a training-induced electrical remodelling of the sinoatrial node (SAN), including a down regulation of the key pacemaker channel HCN4 that carries the pacemaker current I f . Here we investigated post-transcriptional regulation of HCN4 by microRNAs (miRNAs) in the trained SN. Methods and Results: Mice subjected to 60-min swimming twice daily for 28 days (TM) were compared to parallel sedentary mice (SM).TM were bradycardic (cycle length in vivo : SM, 81±1.3 ms; TM, 102±3 ms; n=6, p &lt;0.05). The cycle length of the isolated, denervated SAN (intrinsic heart rate) was also prolonged by exercise training (SM, 110±3 ms; TM, 150±5 ms; n=7, p &lt;0.05). Deep sequencing for miRNAs on SAN punch biopsies revealed 10 differentially expressed miRNAs in TM vs SM (FDR adjusted P &lt;0.05); 8 miRNAs were upregulated, 2 were downregulated. These findings were further confirmed by real-time PCR. We used the computation prediction tools Targetscan and Ingenuity Pathway Analysis to identify miR-423-5p and miR-486-3p as putative miRNAs participating in the post-transcriptional repression of HCN4 in the trained SAN. Both miRNAs had conserved seed sequences in the HCN4 3’UTR. To validate whether these miRNAs directly recognise the 3’UTR of HCN4, they were co-transfected with a construct containing HCN4 3’UTR fused downstream to a luciferase coding sequence in H9c2 cells. Transient transfection of precursor miR-423-5p and miR-486-3p decreased HCN4 3’UTR luciferase reporter activity in H9C2 cells by 47% and 22% respectively, compared with unaltered luciferase activity on co-transfection with control miR or miR-27a. Conclusions: This is the first report of miRNA dysregulation in the trained SAN. We describe a novel molecular mechanism whereby an altered miRNA profile in the trained SAN promotes HCN4 downregulation and altered sinus automaticity. Data suggest miR-423-5p as a potential therapeutic target for bradyarrythmias in the athlete.

A systematic review of surgical ablation versus catheter ablation for atrial fibrillation.

Atrial fibrillation (AF) is an increasingly prevalent condition in the ageing population, with significantly associated morbidity and mortality. Surgical and catheter ablative strategies both aim to reduce mortality and morbidity through freedom from AF. This review consolidates all currently available comparative data to evaluate these two interventions. A systematic search was conducted across MEDLINE, PubMed, Embase, Cochrane Central Register of Controlled Trials and the Cochrane Database of Systematic Reviews from January 2000 until August 2013. All studies were critically appraised and only those directly comparing surgical and catheter ablation were included. Seven studies were deemed suitable for analysis according to the inclusion criteria. Freedom from AF was significantly higher in the surgical ablation group versus the catheter ablation group at 6-month, 12-month and study endpoint follow-up periods. Subgroup analysis demonstrated similar trends, with higher freedom from AF in the surgical ablation group for paroxysmal AF patients. The incidence of pacemaker implantation was higher, while no difference in stroke or cardiac tamponade was demonstrated for the surgical versus catheter ablation groups. Current evidence suggests that epicardial ablative strategies are associated with higher freedom from AF, higher pacemaker implantation rates and comparable neurological complications and cardiac tamponade incidence to catheter ablative treatment. Other complications and risks were poorly reported, which warrants further randomized controlled trials (RCTs) of adequate power and follow-up duration.

Systematic review protocol: surgical ablation versus catheter ablation for atrial fibrillation.

Atrial fibrillation (AF) is an increasingly prevalent condition in the ageing population, with significantly associated morbidity and mortality. Surgical and catheter ablative strategies both aim to reduce mortality and morbidity through freedom from AF. This review consolidates all currently available comparative data to evaluate these two interventions.A systematic search was conducted across MEDLINE, PubMed, Embase, Cochrane Central Register of Controlled Trials and the Cochrane Database of Systematic Reviews from January 2000 until August 2013. All studies were critically appraised and only those directly comparing surgical and catheter ablation were included.Seven studies were deemed suitable for analysis according to the inclusion criteria. Freedom from AF was significantly higher in the surgical ablation group versus the catheter ablation group at 6-month, 12-month and study endpoint follow-up periods. Subgroup analysis demonstrated similar trends, with higher freedom from AF in the surgical ablation group for paroxysmal AF patients. The incidence of pacemaker implantation was higher, while no difference in stroke or cardiac tamponade was demonstrated for the surgical versus catheter ablation groups.Current evidence suggests that epicardial ablative strategies are associated with higher freedom from AF, higher pacemaker implantation rates and comparable neurological complications and cardiac tamponade incidence to catheter ablative treatment. Other complications and risks were poorly reported, which warrants further randomized controlled trials (RCTs) of adequate power and follow-up duration.

Minimally invasive mitral valve repair suggests earlier operations for mitral valve disease

Objective We began minimally invasive mitral valve surgery in August, 1996, to reduce hospital costs, to improve patient recovery, cosmetic appearance, and to decrease trauma, yet maintain the same quality of surgery. To validate this approach we reviewed our entire experience through May 2002. Methods From August 1996 to May 2002, we performed 413 minimally invasive mitral valve operations including 51 mitral valve replacements and 362 mitral valve repairs. Excluding 4 robotically assisted repairs, we evaluated 358 patients, using the mitral valve repairs as the basis for this retrospective survey. These operations were performed through a 6- to 8-cm minimally invasive incision, beginning with parasternal and, most recently, lower ministernotomy (181 patients). The mitral valve reparative techniques include repair of 94 prolapsed anterior leaflets, posterior leaflet resection, leaflet advancement, commissuroplasty, Polytetrafluoroethylene (PTFE; Gore-Tex, W. L. Gore & Associates, Inc, Flagstaff, Ariz) chordal placement, and ring annuloplasty. Cannulation sites varied but primarily utilized a miniaturized system of 24F catheters in both the inferior and superior venae cavae with assisted venous suction. The Cosgrove ring was used in 95% of the patients undergoing this procedure. Results The operative mortality was 0/358. Perioperative morbidity included a 26% incidence of new atrial fibrillation, 2% incidence of pacemaker implantation, 0.5% incidence of deep sternal wound infection, and 1.9% incidence of stroke after an operation. There were 10 arterial and 3 venous complications. The mean length of stay was 6 days and 208 patients stayed ≤5 days. Only 25% of the patients underwent homologous blood transfusion. The mean follow-up was 36 months with 1.4% lost to follow-up. There were 12 late deaths and a survival at 5 years of 95%. There were 21 valves requiring reoperation for structural valve failure of 5.8%. The probability of freedom from reoperation at 5 years was 92%. Conclusion This study documents the safety of minimally invasive mitral valve repair surgery in 358 patients. It also documents a low incidence of homologous blood use, requirement for post–hospital rehabilitation, and general morbidity.

Declining need for pacemaker implantation after cardiac transplantation.

The need for permanent pacemaker implantation was retrospectively reviewed in 436 consecutive cardiac transplant recipients at our center between 1985 and 1998. The incidence of pacemaker implantation was examined in three arbitrarily defined periods: period 1, 1985-1990, before a review of pacemaker implantation policy; period 2, 1991-1995, after a change in policy to delay pacemaker implantation resulting from the review; and period 3, 1996-1998, after audit of this policy change, and the introduction of a change in surgical technique, from the standard atrial anastomosis to the bicaval anastomosis. Pacemaker implantation was not required in any recipient after the change in surgical technique, suggesting that the bicaval technique preserves sinus node function much better than does the standard atrial anastomosis.