Initial Experience, Safety, and Feasibility of Left Bundle Branch Area Pacing: A Multicenter Prospective Study.

OBJECTIVES: This study sought to evaluate the safety and feasibility of conduction system pacing by performing left bundle branch area pacing (LBBAP). BACKGROUND: There are limited data from single centers showing that LBBAP may circumvent the technical and electrophysiological challenges encountered with His bundle pacing. METHODS: Patients referred for pacemaker implantation at 2 centers between February 1, 2019, and March 31, 2020, were considered for LBBAP. LBBAP was performed by implanting a lumen-less, exposed helix lead approximately 2 cm distal to the His bundle and deep into the septum using a specialized delivery sheath. Implant success rates, complications, and electrophysiological parameters were assessed. RESULTS: LBBAP was successful in 305 of 341 patients (89%). Mean age was 72 ± 12 years; 45% were women; and 39% had QRS duration (QRSd) >130 ms, 22% right bundle branch block, 11% left bundle branch block, and 6% intraventricular conduction defect. Pacing indications were sinus node dysfunction in 28.7%, atrioventricular block in 52.5%, cardiac resynchronization therapy in 8.8%, and refractory atrial fibrillation in 10% of patients. Procedural duration was 74.7 ± 34 min and fluoroscopic time was 10.4 ± 8.1 min. The mean baseline QRSd and paced QRSd in the overall cohort was 114 ± 29.8 ms versus 112 ± 11.7 ms (p < 0.001) and in patients with infra-Hisian disease was 144.5 ± 19 ms versus 115 ± 12 ms (p < 0.001), respectively. Mean left ventricular activation time was 71.7 ± 11 ms at high output and 74.7 ± 11 ms at low output. LBB potentials were noted in 41% patients. Pacing threshold and R waves were 0.74 ± 0.3 V at 0.4 ms and 10.7 ± 4.9 mV at time of implantation and were stable at 1-, 3-, 6-, and 12-month follow-ups. The only major complications were 3 LBBAP lead dislodgements, 2 within 24 h and 1 at 2 weeks. CONCLUSIONS: LBBA pacing is safe, feasible, and a reliable alternative to His bundle pacing for providing physiological pacing. Randomized controlled studies are needed to confirm the safety, feasibility, and clinical outcomes of LBBAP.

Morbidity and mortality in patients precluded for transvenous pacemaker implantation: Experience with a leadless pacemaker.

BACKGROUND: The Micra transcatheter pacemaker is a safe and effective alternative to transvenous permanent pacemakers (TV-PPMs). However, the safety profile and mortality outcomes of Micra implantation in patients deemed poor candidates for TV-PPM are incompletely understood. OBJECTIVE: The purpose of this study was to evaluate safety and all-cause mortality in patients undergoing Micra implantation stratified by whether they were precluded for therapy with a TV-PPM. METHODS: Patients from the Micra clinical trials were divided into groups on the basis of whether the implanter considered the patient to be precluded from receiving a TV-PPM. Micra groups were compared with one another as well as with a historical cohort of patients who received a single-chamber TV-PPM. RESULTS: A total of 2817 patients underwent a Micra implantation attempt, of whom 546 (19%) patients deemed ineligible for TV-PPM implantation for reasons such as venous access issues or prior device infections. Both acute mortality (2.75% vs 1.32%; P=.022) and total mortality at 36 months (38.1% vs 20.6%; P<.001) were significantly higher in the precluded group than in the nonprecluded group. Mortality was similar among nonprecluded patients and patients implanted with a TV-PPM. The major complication rate through 36 months was similar between the 2 Micra groups (3.81% vs 4.30%; P=.40). CONCLUSION: All-cause mortality is higher in Micra patients deemed ineligible for TV-PPM implantation than in nonprecluded Micra patients and those who received a TV-PPM, in part related to a higher incidence of chronic comorbidities in these patients. The overall major complication rate was low and did not differ by preclusion status. CLINICAL TRIAL REGISTRATION: Micra Post-Approval Registry ClinicalTrials.gov identifier: NCT02536118; Micra Continued Access Study ClinicalTrials.gov identifier: NCT02488681; Micra Transcatheter Pacing Study ClinicalTrials.gov identifier: NCT02004873; Medtronic Product Surveillance Registry ClinicalTrials.gov identifier: NCT01524276.

Painful Left Bundle Branch Block Syndrome Successfully Treated With Left Bundle Branch Area Pacing.

Chest pain may be rarely associated with left bundle branch block (LBBB)-mediated ventricular dys-synchrony has been reported. This article reports 2 such cases, where left bundle branch area pacing resulted in resolution of the LBBB and associated symptoms. By adjusting the atrioventricular delays, the QRS duration was narrowed further by achieving fusion with the intrinsic activation wavefront. (Level of Difficulty: Beginner.).

Full stent expansion of chronic total occlusion lesions requires prolonged inflation.

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has been associated in some studies with higher target vessel revascularization (TVR) rates than non-CTO PCI. Optimal stent inflation time and its effect on TVR in CTO PCI is unknown. We investigated the time required for stent deployment using the previously described pressure optimized protocol (POP), which uses stent balloon pressure stability rather than an arbitrary inflation time as an end point for balloon deflation. We also compared TVR with CTO PCI vs non-CTO using the POP protocol in both groups. METHODS: Patients with successful CTO PCI using POP between 2012 and 2015 were included. Patients having non-CTO PCI using POP and matched for stent diameter and length and temporal proximity constituted the control group to compare inflation time (n=83 each). TVR at 1year was compared between PCI during the time period using POP (CTO=83, non-CTO=263). RESULTS: Stent inflation time to achieve optimal stent inflation using POP was longer in CTO vs non-CTO lesions (136±60 vs 108±51s, p=0.001). TVR at 365days was similar in CTO and non-CTO cohorts (2.4% vs 2.6%, p=0.9). CONCLUSION: Stent expansion using POP in CTO lesions requires longer inflation duration but leads to similar TVR rates at 1year in CTO PCI compared with non-CTO PCI.

Incidence of Thromboembolic Complications Within 30 Days of Electrical Cardioversion Performed Within 48 Hours of Atrial Fibrillation Onset.

OBJECTIVES: This study sought to compare the risk of thromboembolism after cardioversion within 48 h of atrial fibrillation (AF) onset in patients therapeutically versus not therapeutically anticoagulated. BACKGROUND: Although guidelines do not mandate anticoagulation for cardioversion within 48 h of AF onset, risk of thromboembolism in this group has been understudied. METHODS: Patients undergoing cardioversion within 48 h after AF onset were identified from a prospectively collected database and retrospectively reviewed to determine anticoagulation status and major thromboembolic events within 30 days of cardioversion. RESULTS: Among 567 cardioversions in 484 patients without therapeutic anticoagulation (mean CHA2DS2-VASc score, 2.3 ± 1.7), 6 had neurological events (1.06%), all in patients on aspirin alone. Among 898 cardioversions in 709 patients on therapeutic anticoagulation (mean CHA2DS2-VASc score, 2.6 ± 1.7; p = 0.017), 2 neurological events occurred (0.22%; OR: 4.8; p = 0.03), both off anticoagulation at the time of stroke. No thromboembolic events occurred in patients with CHA2DS2-VASc score <2 (p = 0.06) or in patients with postoperative AF. CONCLUSIONS: In patients with acute-onset AF, odds of thromboembolic complications were almost 5 times higher in patients without therapeutic anticoagulation at the time of cardioversion. However, no events occurred in post-operative patients and in those with CHA2DS2-VASc scores of <2, supporting the utility of accurate assessment of AF onset and risk stratification in determining the need for anticoagulation for cardioversion of AF <48 h in duration.

In-hospital mortality and stroke after surgical aortic valve replacement: A nationwide perspective.

BACKGROUND: Stroke is a widely recognized complication after aortic valve replacement (AVR), especially among elderly patients. The literature contains substantial variability in reports of the actual incidence of stroke after AVR among high-risk patients. Our objective was to define risk of stroke in patients undergoing surgical AVR, using a large national database. METHODS: We used the 2002 to 2011 Nationwide Inpatient Sample database for this analysis. All patients undergoing isolated AVR, or AVR with coronary artery bypass grafting (AVR + CABG), were identified using standard International Classification of Diseases codes. In-hospital mortality and any adverse neurologic event were the primary outcomes of the study. RESULTS: The incidence of in-hospital mortality was 3.0% and 5.1%, respectively, among patients undergoing isolated AVR and AVR + CABG; it was significantly lower in high-volume centers. The incidence of any adverse neurologic event was 2.0% and 2.9%, respectively, among patients undergoing isolated AVR, and AVR + CABG. We demonstrated a progressive increase in the risk of in-hospital mortality and adverse neurologic events with increasing age. Neurologic events increased with age, from 1.3% for patients aged <70 years, to 3.2% for those aged >85 years, for isolated AVR; and from 2.3% to 3.6% for AVR + CABG. The incidence of in-hospital mortality was as high as 5.7% and 7.4%, respectively, among patients aged >85 years undergoing isolated AVR, and AVR + CABG. Similarly, the incidence of any adverse neurologic event was 3.2% and 3.6%, respectively, among patients aged >85 years undergoing isolated AVR, and AVR + CABG. In addition, the risk of adverse neurologic events was significantly higher in the high-risk surgical cohort, compared with the low-risk surgical cohort (odds ratio [95% confidence interval]; isolated AVR: 2.38 [1.99-2.86]; AVR + CABG: 1.88 [1.57-2.24]). CONCLUSIONS: The incidence of in-hospital mortality and adverse neurologic events was significantly higher among patients with advanced age and elevated surgical risk.

Length of stay and long-term mortality following ST elevation myocardial infarction.

BACKGROUND: Over the last few decades, there has been a significant reduction in hospital length of stay (LOS) among patients undergoing percutaneous intervention (PCI) for ST elevation myocardial infarction (STEMI). Although studies have looked at predictors of long hospital stay after STEMI, the impact of LOS on long-term outcomes after PCI remains unknown. We aimed to evaluate the association between LOS at the time of index hospitalization for PCI and long-term mortality among patients presenting with STEMI. METHODS: We examined all patients undergoing PCI for STEMI at the Cleveland Clinic Catheterization Laboratory between 2002 and 2011. Long-term all-cause mortality was assessed using the Social Security Death Index and electronic medical record review. LOS was extracted from the discharge summary of the index hospitalization. RESULTS: A total of 1,963 patients were included in the study. Of these 1,963 patients undergoing PCI for STEMI, 126 (6.4%) died during the index hospitalization. Among survivors of this hospitalization, we observed a significant increase in long-term mortality with an increase in LOS during index hospitalization (P < 0.001). Adjustment for demographic and clinical characteristics yielded statistically significant increased mortality among patients with LOS of 6-10 days [HR (95% CI): 2.2 (1.3-3.5)] and LOS > 10 days [HR (95% CI): 2.6 (1.6-4.3)], in comparison with patients with LOS of 1-2 days. CONCLUSIONS: Long hospital stay after PCI among patients with STEMI was associated with an increased long-term mortality. A long hospital stay may be used as a marker to identify patients at higher risk for long-term mortality.

Renin-Angiotensin System Antagonists in Patients Without Left Ventricular Dysfunction After Percutaneous Intervention for ST-Segment Elevation Myocardial Infarction.

There is a paucity of evidence on the impact of angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB) on long-term outcomes in patients with ejection fraction (EF) >40% after primary percutaneous coronary intervention for ST-segment elevation myocardial infarction (STEMI). We compared long-term all-cause mortality between patients with left ventricular ejection fraction (LVEF) >40% discharged on ACEi/ARB with patients who were discharged on neither of these agents. Patients discharged after percutaneous intervention for STEMI from our catheterization laboratories from January 2002 to December 2011 were considered for inclusion. Patients were excluded if they had LVEF <40% or chronic kidney disease or hypotension (systolic blood pressure <90 mm Hg any time after the procedure). Long-term mortality and discharge medications were determined using the Social Security Death Index and electronic medical record review, respectively. A total of 988 patients were included. The median follow-up duration was 4.6 years. Kaplan-Meier analysis showed no significant difference in long-term all-cause mortality in patients discharged on ACEi/ARB compared with those who were not discharged on these medications. The number needed to treat to prevent 1 death at 1 year was 714. In addition, multivariable Cox proportional hazard modeling failed to demonstrate any beneficial effect of ACEi/ARB similar to Kaplan-Meir analysis (hazard ratio 0.88, 95% confidence interval 0.57 to 1.36). In conclusion, we found no significant benefit in long-term mortality using ACEi/ARB in patients with LVEF >40% after primary percutaneous coronary intervention for STEMI.

Comparison of acute elastic recoil between the SAPIEN-XT and SAPIEN valves in transfemoral-transcatheter aortic valve replacement.

BACKGROUND: The SAPIEN-XT is a newer generation balloon-expandable valve created of cobalt chromium frame, as opposed to the stainless steel frame used in the older generation SAPIEN valve. We sought to determine if there was difference in acute recoil between the two valves. METHODS: All patients who underwent transfemoral-transcatheter aortic valve replacement using the SAPIEN-XT valve at the Cleveland Clinic were included. Recoil was measured using biplane cine-angiographic image analysis of valve deployment. Acute recoil was defined as [(valve diameter at maximal balloon inflation) - (valve diameter after deflation)]/valve diameter at maximal balloon inflation (reported as percentage). Patients undergoing SAPIEN valve implantation were used as the comparison group. RESULTS: Among the 23 mm valves, the mean (standard deviation-SD) acute recoil was 2.77% (1.14) for the SAPIEN valve as compared to 3.75% (1.52) for the SAPIEN XT valve (P = 0.04). Among the 26 mm valves, the mean (SD) acute recoil was 2.85% (1.4) for the SAPIEN valve as compared to 4.32% (1.63) for the SAPIEN XT valve (P = 0.01). Multivariable linear regression analysis demonstrated significantly greater adjusted recoil in the SAPIEN XT valves as compared to the SAPIEN valves by 1.43% [(95% CI: 0.69-2.17), P < 0.001]. However, the residual peak gradient was less for SAPIEN XT compared to SAPIEN valves [18.86 mm Hg versus 23.53 mm Hg (P = 0.01)]. Additionally, no difference in paravalvular leak was noted between the two valve types (P = 0.78). CONCLUSIONS: The SAPIEN XT valves had significantly greater acute recoil after deployment compared to the SAPIEN valves. Implications of this difference in acute recoil on valve performance need to be investigated in future studies.

Outcomes and resource utilization in ST-elevation myocardial infarction in the United States: evidence for socioeconomic disparities.

BACKGROUND: Socioeconomic status (SES) as reflected by residential zip code status may detrimentally influence a number of prehospital clinical, access-related, and transport variables that influence outcome for patients with ST-elevation myocardial infarction (STEMI) undergoing reperfusion. We sought to analyze the impact of SES on in-hospital mortality, timely reperfusion, and cost of hospitalization following STEMI. METHODS AND RESULTS: We used the 2003-2011 Nationwide Inpatient Sample database for this analysis. All hospital admissions with a principal diagnosis of STEMI were identified using ICD-9 codes. SES was assessed using median household income of the residential zip code for each patient. There was a significantly higher mortality among the lowest SES quartile as compared to the highest quartile (OR [95% CI]: 1.11 [1.06 to 1.17]). Similarly, there was a highly significant trend indicating a progressively reduced timely reperfusion among patients from lower quartiles (OR [95% CI]: 0.80 [0.74 to 0.88]). In addition, there was a lower utilization of circulatory support devices among patients from lower as compared to higher zip code quartiles (OR [95% CI]: 0.85 [0.75 to 0.97]). Furthermore, the mean adjusted cost of hospitalization among quartiles 2, 3, and 4, as compared to quartile 1 was significantly higher by $913, $2140, and $4070, respectively. CONCLUSIONS: Patients residing in zip codes with lower SES had increased in-hospital mortality and decreased timely reperfusion following STEMI as compared to patients residing in higher SES zip codes. The cost of hospitalization of patients from higher SES quartiles was significantly higher than those from lower quartiles.

Percutaneous left atrial appendage occlusion for stroke prophylaxis in nonvalvular atrial fibrillation: a systematic review and analysis of observational studies.

OBJECTIVES: The goal of this study was to provide a systematic review and analysis of observational studies on percutaneous left atrial appendage (LAA) occlusion for stroke prophylaxis in nonvalvular atrial fibrillation (NVAF). BACKGROUND: A recent randomized controlled trial in patients with NVAF suggested noninferiority of percutaneous LAA occlusion versus medical management for stroke prevention. However, the use of percutaneous devices remains controversial because of limited literature on their efficacy and safety. We performed a systematic analytical review of existing observational studies to assess the rate of neurological events for patients treated with occlusion devices. METHODS: A comprehensive search of the Medline, Scopus, and Web of Science databases from inception through August 1, 2013, was conducted using pre-defined criteria. We included studies reporting implantation in at least 10 patients and a follow-up of 6 months or more. RESULTS: In 17 eligible studies, a total of 1,052 devices were implanted in 1,107 patients with 1,586.4 person-years (PY) of follow-up. The adjusted incidence rate of stroke was 0.7/100 PY (95% confidence interval [CI]: 0.3 to 1.1/100 PY), of transient ischemic attacks was 0.5/100 PY (95% CI: 0.1 to 1.8/100 PY), and of combined neurological events (strokes or transient ischemic attacks) was 1.1/100 PY (95% CI: 0.6 to 1.6/100 PY). Access site vascular complications and pericardial effusion were the most commonly observed procedural complications at a rate of 8.6% (95% CI: 6.3% to 11.7%) and 4.3% (95% CI: 3.1% to 5.9%), respectively. CONCLUSIONS: Our systematic review suggested comparable efficacy of LAA occlusion devices compared with historical controls treated with adjusted-dose warfarin and other anticoagulation strategies for prevention of stroke in patients with NVAF.