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Abstract Background and Aims Prior reports have demonstrated a favourable safety and efficacy profile of the Micra leadless pacemaker over mid-term follow-up; however, long-term outcomes in real-world clinical practice remain unknown. Updated performance of the Micra VR leadless pacemaker through five years from the worldwide post-approval registry (PAR) was assessed. Methods All Micra PAR patients undergoing implant attempts were included. Endpoints included system- or procedure-related major complications and system revision rate for any cause through 60 months post-implant. Rates were compared through 36 months post-implant to a reference dataset of 2667 transvenous pacemaker patients using Fine–Gray competing risk models. Results 1809 patients were enrolled between July 2015 and March 2018 and underwent implant attempts from 179 centres in 23 countries with a median follow-up period of 51.1 months (IQR: 21.6–64.2). The major complication rate at 60 months was 4.5% [95% confidence interval (CI): 3.6%–5.5%] and was 4.1% at 36 months, which was significantly lower than the 8.5% rate observed for transvenous systems (HR: .47, 95% CI: .36–.61; P < .001). The all-cause system revision rate at 60 months was 4.9% (95% CI: 3.9%–6.1%). System revisions among Micra patients were mostly for device upgrades (41.2%) or elevated thresholds (30.6%). There were no Micra removals due to infection noted over the duration of follow-up. At 36 months, the system revision rate was significantly lower with Micra vs. transvenous systems (3.2% vs. 6.6%, P < .001). Conclusions Long-term outcomes with the Micra leadless pacemaker continue to demonstrate low rates of major complications and system revisions and an extremely low incidence of infection.

Background: Premature ventricular contractions (PVCs) are associated with an increased risk of implanting implantable cardioverter defibrillator (ICD). Therefore, our study aimed to predict the risk factors for implantable cardioverter defibrillator in patients with premature ventricular contractions. Methods: A total of 309 patients (male 57%, mean age 66.73±16.12) in Olmstate Countywho had premature ventricular contractions and received a 24-hour electrocardiography monitoring were included between January 1994 and September 2010 at Mayo Clinic, Rochester, Minnesota. All these patients were continuously followed o Jun 2015. Student’s t-test, Chi-square, univariate and multivariate Logistic regression models were used to estimate the relationship between the risk factors and the incidence of implanting implantable cardioverter defibrillator (ICD) in PVCs patients. Kaplan–Meier curve of survival in PVCs patients with ICD or free-ICD. Results: The average follow-up time was 9.3±3.9 years, in which 43 (13.9%) patients died and 24 (7.8%) patients had received ICD therapy. Sex, age, pulse pressure, early repolarization syndrome (ERS), heart rate, PVC coupling interval, QRS duration, left ventricular ejection fraction (LVEF), left ventricular end-diastolic dimension (LVEDD) and left ventricular end-systolic dimension (LVESD), diabetes were significantly associated with the mortality and the incidence of implanting ICD. Using a multivariate logistic regression model adjusted for potential confounders, showed that LVEF (OR=0.916, 95% CI:0.881 to 0.953, p<0.001) and pulse pressure (OR=1.032, 95% CI:1.001-1.064, p=0.045) were independent factors for ICD implant in PVCs patients. Moreover, implantation of ICD may not reduce mortality in patients with ventricular premature. Conclusions: Increased pulse pressure was associated a higher incidence of ICD in PVCs patients, among many electrocardiographic and clinical variables studied. We also showed that PVs patients with ICD were at high risk of death, and the great pulse pressure was linked with higher morality in PVCs patients.

BACKGROUND: The incidence and prognosis of right bundle branch block (RBBB) following transcatheter aortic valve replacement (TAVR) are unknown. Hence, we sought to characterize the incidence of post-TAVR RBBB and determine associated risks of permanent pacemaker (PPM) implantation and mortality. METHODS: All patients 18 years and above without preexisting RBBB or PPM who underwent TAVR at US Mayo Clinic sites and Mayo Clinic Health Systems from June 2010 to May 2021 were evaluated. Post-TAVR RBBB was defined as new-onset RBBB in the postimplantation period. The risks of PPM implantation (within 90 days) and mortality following TAVR were compared for patients with and without post-TAVR RBBB using Kaplan-Meier analysis and Cox proportional hazards modeling. The risks of PPM implantation (within 90 days) and mortality following TAVR were compared for patients with and without post-TAVR RBBB using Kaplan-Meier analysis and Cox proportional hazards modeling. RESULTS: Of 1992 patients, 15 (0.75%) experienced new RBBB post-TAVR. There was a higher degree of valve oversizing among patients with new RBBB post-TAVR versus those without (17.9% versus 10.0%; P =0.034). Ten patients (66.7%) with post-TAVR RBBB experienced high-grade atrioventricular block and underwent PPM implantation (median 1 day; Q1, 0.2 and Q3, 4), compared with 268/1977 (13.6%) without RBBB. Following propensity score adjustment for covariates (age, sex, balloon-expandable valve, annulus diameter, and valve oversizing), post-TAVR RBBB was significantly associated with PPM implantation (hazard ratio, 8.36 [95% CI, 4.19–16.7]; P <0.001). No statistically significant increase in mortality was seen with post-TAVR RBBB (hazard ratio, 0.83 [95% CI, 0.33–2.11]; P =0.69), adjusting for age and sex. CONCLUSIONS: Although infrequent, post-TAVR RBBB was associated with elevated PPM implantation risk. The mechanisms for its development and its clinical prognosis require further study.

Background: The outcomes of leadless pacemaker (LP) implantation after transvenous lead removal (TLR) of infected cardiac implantable electronic devices (CIED) are not well-established. Objective: This study sought to describe the outcomes of LP implantation following TLR of infected CIED. Method: We conducted a literature search using PubMed and Embase for a combination of term including leadless pacemaker implantation, transvenous lead extraction, transvenous lead removal , transvenous lead explant , infected cardiac implantable electronic device . The inclusion criterion was LP implantation after TLR of infected CIED. The exclusion criterion was TLR for non-infectious reason. Study end-points were procedural complications and LP infection. Result: Of 132 publications reviewed, 13 studies with a total of 253 patients (74 ± 14 years of age, 69% males) were included. Amongst, 56.8% had systemic CIED infection and 43.2% had isolated pocket infection. Staphylococcus Aureus was the most common causative organism in 33% of the reported patients. Of 253 patients included, 105 patients (41.5%) underwent concomitant LP implantation during TLR procedure, and 36 patients (14.2%) had transvenous pacing as a bridge from TLR to LP implantation. During the LP implantation, 1 patient (0.4%) had an intra-procedural complication requiring sternotomy. Post-LP implantation, 2 patients (0.8%) developed groin hematoma, 2 patients (0.8%) developed femoral arteriovenous fistula, and 1 patient (0.4%) developed pericardial effusion requiring pericardiocentesis. During a mean follow-up of 11.3 ±10.6 months, 3 patients (1.2%) developed pacemaker syndrome, 1 patient (0.4%) developed acute on chronic heart failure exacerbation, and only 1 patient (0.4%) developed LP-related infection requiring LP retrieval. Conclusion: This study suggests that LP implant is feasible and safe post-removal of infected CIED with cumulative adverse events at 4% and a reinfection rate of 0.4%.

To date, biventricular pacing (BiVP) has been the standard pacing modality for cardiac resynchronisation therapy. However, it is non-physiological, with the activation spreading between the left ventricular epicardium and right ventricular endocardium. Up to one-third of patients with heart failure who are eligible for cardiac resynchronisation therapy do not derive benefit from BiVP. Conduction system pacing (CSP), which includes His bundle pacing and left bundle branch area pacing, has emerged as an alternative to BiVP for cardiac resynchronisation. There is mounting evidence supporting the benefits of CSP in achieving synchronous ventricular activation and repolarisation. The aim of this review is to summarise the current options and outcomes of CSP when used for cardiac resynchronisation in patients with heart failure.

AbstractIntroductionLeft bundle branch area pacing (LBBP) is a novel conduction system pacing method to achieve effective physiological pacing and an alternative to cardiac resynchronization therapy (CRT) with biventricular pacing (BVP) for patients with heart failure with reduced ejection fraction (HFrEF). We conduted this meta‐analysis and systemic review to review current data comparing BVP and LBBP in patients with HFrEF and indications for CRT.MethodsWe searched PubMed/Medline, Web of Science, and Cochrane Library from the inception of the database to November 2022. All studies that compared LBBP with BVP in patients with HFrEF and indications for CRT were included. Two reviewers performed study selection, data abstraction, and risk of bias assessment. We calculated risk ratios (RRs) with the Mantel–Haenszel method and mean difference (MD) with inverse variance using random effect models. We assessed heterogeneity using the I2 index, with I2 > 50% indicating significant heterogeneity.ResultsTen studies (9 observational studies and 1 randomized controlled trial; 616 patients; 15 centers) published between 2020 and 2022 were included. We observed a shorter fluoroscopy time (MD: 9.68, 95% confidence interval [CI]: 4.49–14.87, I2 = 95%, p < .01, minutes) as well as a shorter procedural time (MD 33.68, 95% CI: 17.80–49.55, I2 = 73%, p < .01, minutes) during the implantation of LBBP CRT compared to conventional BVP CRT. LBBP was shown to have a greater reduction in QRS duration (MD 25.13, 95% CI: 20.06–30.20, I2 = 51%, p < .01, milliseconds), a greater left ventricular ejection fraction improvement (MD: 5.80, 95% CI: 4.81–6.78, I2 = 0%, p < .01, percentage), and a greater left ventricular end‐diastolic diameter reduction (MD: 2.11, 95% CI: 0.12–4.10, I2 = 18%, p = .04, millimeter). There was a greater improvement in New York Heart Association function class with LBBP (MD: 0.37, 95% CI: 0.05–0.68, I2 = 61%, p = .02). LBBP was also associated with a lower risk of a composite of heart failure hospitalizations (HFH) and all‐cause mortality (RR: 0.48, 95% CI: 0.25–0.90, I2 = 0%, p = .02) driven by reduced HFH (RR: 0.39, 95% CI: 0.19–0.82, I2 = 0%, p = .01). However, all‐cause mortality rates were low in both groups (1.52% vs. 1.13%) and similar (RR: 0.98, 95% CI: 0.21–4.68, I2 = 0%, p = .87).ConclusionThis meta‐analysis of primarily nonrandomized studies suggests that LBBP is associated with a greater improvement in left ventricular systolic function and a lower rate of HFH compared to BVP. There was uniformity of these findings in all of the included studies. However, it would be premature to conclude based solely on the current meta‐analysis alone, given the limitations stated. Dedicated, well‐designed, randomized controlled trials and observational studies are needed to elucidate better the comparative long‐term efficacy and safety of LBBP CRT versus BIV CRT.

Background: Long-term outcomes of lead management strategies of lead abandonment (LA) or transvenous lead extraction (TLE) during cardiac implantable electronic devices (CIED) procedures requiring lead addition or replacement remain unclear. Hypothesis: We hypothesized that there is no difference in long-term (10-year) outcomes of LA versus TLE during CIED procedures requiring lead addition. Methods: We performed a retrospective cohort study of a population residing in seven adjacent counties of southeastern Minnesota with follow-up at the Mayo Clinic and its health systems. Patients who underwent LA or TLE for sterile leads from January 1, 2000, to January 1, 2011, and had follow-up for at least 10-years or until their death were included. Outcomes were identified through a detailed chart review of the electronic health record from within the Mayo Clinic system. Results: A total of 172 patients were included in the study with 153 patients who underwent LA and 19 who underwent TLE for sterile leads. In long-term follow-up, indications for subsequent lead extraction arose in 9.1% (n=14) of patients with initial LA and 5.3% (n=1) in patients with initial TLE, after an average of 7-years. Moreover, out of 14 patients, who required secondary extraction in the LA cohort, 28.6% did not proceed with the extraction. Of the remaining 10 patients, 60% had clinical success and 40% had a clinical failure with the extraction. Subsequent device upgrades or revisions were performed in 18.3% of patients in the LA group and 31.6% in the TLE group, with no significant differences in procedural challenges such as requiring balloon venoplasty or serial dilation (5.2% vs. 5.3%, P=1.0). There was no difference in 10-year survival probability among LA group and TLE group (P=0.64). Conclusion: Indications for subsequent extraction arose in 9.1% of patients with the initial LA approach for sterile leads after an average of 7.3 years and 28.6% did not proceed with the extraction. Of the patients who underwent the subsequent extraction, 60% had clinical success and 40% had a clinical failure. There was no difference in 10-year survival probability between patients with the initial LA approach or TLE approach.

Background: Recognition of the causes of early mortality after atrial fibrillation (AF) catheter ablation is essential for the improvement of patient safety. Objective: This study sought to determine the causes of early mortality (≤90-days) after AF ablation and to further understand the circumstances surrounding death after the procedure. Methods: We performed a retrospective analysis of AF ablation from January 1, 2013, to December 1, 2021 at the Mayo Clinic (Rochester, Phoenix, and Jacksonville). Causes of death were identified through a comprehensive chart review of the electronic health record from within the Mayo Clinic system and outside records when available. Results: A total of 6,723 patients were included in the study. The 30-day and 90-day all-cause mortality rates were 0.09% and 0.22%, respectively. Among all 90-day deaths, majority of the deaths (73.3%) did not have a direct relationship with the procedure. Sudden death was the most common cause of early death (20%), followed by peri-procedural stroke (13%), respiratory failure (13%), atrioesophageal fistula (13%), infection (7%), heart failure (7%), and traumatic brain injury (7%). The 90-day mortality rate directly due to AF ablation procedural complications was 0.06%. Most of the early deaths (93.3%) occurred after discharge from index hospitalization, among which 64.3% were readmitted before their death, 14% died at home, and 7% were discharged on comfort care and died in hospice. The main reason for readmission leading to death was respiratory failure (33%). Conclusion: Atrial fibrillation ablation procedure has a 90-day mortality of 0.22% and the most common cause of early mortality was sudden death. The majority (73.3%) of early mortality was not directly associated with a procedural complication, and the mortality rate due to complications associated with the AF ablation procedure was 0.06%.

Background: Recognition of the causes of early mortality after ventricular tachycardia (VT) ablation in patients with reduced left ventricular ejection fraction is an essential step toward improving post-procedural outcomes. Objective: This study sought to determine the causes of early mortality (≤30-days) after VT ablation in patients with reduced left ventricular ejection fraction and to understand further the circumstances surrounding death after the procedure. Methods: We performed a retrospective analysis of all patients undergoing VT ablation in patients with reduced left ventricular ejection fraction from January 1, 2013, to November 10, 2021, at the Mayo Clinic (Rochester, Phoenix, and Jacksonville). Causes of death were identified through a detailed chart review of the electronic health record within the Mayo Clinic system and outside records. Results: A total of 503 patients (mean age 63 ± 13 years, 11.2% female) with EF <50% were included in the study. The 30-day all-cause mortality rate was 5% (n=25), and the mortality rate due to a procedural complication was 0.4%. Among all 30-day deaths, recurrent VT was the most common primary cause of death (44%). This was followed by decompensated heart failure (28%), procedure-related death (8%), cerebrovascular accident (CVA) (4%), and infection (4%). Most patients (91%) who died from VT had the VT recurrence within three days of the ablation. 76% of patients with early mortality had delayed referral for VT ablation, and 72% opted for comfort care before death. Conclusions: The overall early mortality (≤30-days) rate after catheter ablation of VT in patients with reduced left ventricular ejection fraction was 5%, but the death rate directly due to a procedural complication was only 0.4%. The most common cause of death was recurrent VT, followed by heart failure. Further research into ablation strategies is vital to improving the safety, efficacy, and durability of VT ablation.