Scott, Luis R.

Background: Despite the optimal efficacy of catheter ablation for ventricular tachycardia (VT), recurrence of VT can occur post-procedurally. However, data on the high-risk population for VT recurrence and the in-hospital outcomes remain scarce. Objective: This study aimed to determine the predictors of 30-day readmission for recurrent VT after catheter ablation of VT and assess the in-hospital outcomes. Method: Using the all-payer, nationally representative Nationwide Readmissions Database, we identified the patients aged ≥18 years who underwent catheter ablation for VT and were readmitted within 30 days because of recurrent VT from 2017 to 2020. We performed unweighted univariable and multivariable analyses to determine the outcomes and to identify the patient and hospital variables that were predictive of 30-day readmissions for recurrent VT. A p-value of <0.05 is considered statistically significant. Results: In our analysis, a total of 4,102 patients were discharged alive after VT ablation, of which 278 (6.8%) were readmitted within 30 days for recurrent VT. Recurrent VT was also the most common cause of 30-day readmission (47.7%, n=278/583). Compared to non-recurrent VT readmission, readmission due to recurrent VT had higher mortality during rehospitalization (7.55% vs 3.72%, p<0.01) and higher cumulative hospitalization cost ($57584 vs $37846, p<0.01). Via multivariable analysis, congestive heart failure (aOR: 1.84; 95% CI: 1.07-3.17; P=0.03) and non-elective index admissions (aOR: 1.88; 95% CI: 1.32-2.68; P<0.01) were the independent predictors of 30-day readmission for recurrent VT. Conclusion: Recurrent VT was the most common cause of 30-day readmission following VT ablation. Congestive heart failure and non-elective index admissions were the independent predictors of 30-day readmissions for recurrent VT. These highlight the importance of further research in ablation strategies to improve the efficacy of VT ablation.

AbstractBackgroundReal‐world clinical data on the adverse events related to the use of cryoballoon catheter for pulmonary vein isolation remains limited.ObjectiveTo report and describe the adverse events related to the use of Artic Front cryoballoon catheters (Arctic Front, Arctic Front Advance, and Arctic Front Advance Pro) reported in the Food and Drug Administration's (FDA) Manufacturers and User Defined Experience (MAUDE) database.MethodsWe reviewed all the adverse events reported to the FDA MAUDE database over a 10.7‐year study period from January 01, 2011 to September 31, 2021. All events were independently reviewed by two physicians.ResultsDuring the study period, a total of 320 procedural‐related adverse events reported in the MAUDE database were identified. The most common adverse event was transient or persistent phrenic nerve palsy (PNP), accounting for 48% of all events. This was followed by cardiac perforation (15%), pulmonary vein stenosis (8%), transient ischemic attack or stroke (6%), vascular injury (4%), transient or persistent ST‐elevation myocardial infarction (3%), hemoptysis (2%), pericarditis (2%), and esophageal ulcer or fistula (1%). There were six reported intra‐procedural death events as a result of cardiac perforation.ConclusionThe two most common procedural adverse events associated with cryoballoon ablation were PNP and cardiac perforation. All cases of procedural mortality were due to cardiac perforation.

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 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.

Background: Recognition of the infectious characteristics among the sepsis-related early mortality after transvenous lead removal (TLR) is an essential step to improving patient outcomes. Objective: This study sought to understand the infectious characteristic and circumstances among the sepsis-related early mortality after TLR. Methods: We performed a retrospective analysis of all patients undergoing TLR from January 1, 2001, to January 1, 2021 at the Mayo Clinic (Rochester, Phoenix, and Jacksonville). Patient details were identified through a detailed chart review of the electronic health record from within the Mayo Clinic system and outside records when available. Results: A total of 2,319 patients were included in the study. The overall 30-day sepsis-related mortality rate was 1.25% (n=29). Among the sepsis-related deaths, 24 patients (83%) had systemic cardiac implantable electronic device (CIED) infection, and 4 patients (14%) initially had isolated pocket infection. The average time from admission to TLR was 11 days. MSSA was the most common organism (n=8, 28%), and this was followed by MRSA (n=4, 14%) and Candida (n=3, 10%). Twenty of these patients (69%) had vegetation on the echocardiogram: vegetation on lead only in 9 patients, vegetation on both valve and lead in 8 patients, and vegetation on valve only in 3 patients. Among valvular vegetations, 5 patients had tricuspid valve vegetations, 3 patients had aortic valve vegetations, 2 patients had mitral valve vegetations, and 1 patient had both mitral and aortic valve vegetation. The average size of vegetation was 1.3±0.8 x 1.1±0.6 cm. Conclusions: The 30-day sepsis-related mortality rate was 1.25%. Among the sepsis-related early deaths, MSSA was the most common organism, and more than two-thirds (69%) of the patients had vegetations on cardiac imaging. This highlights the importance of further research to improve the infection outcome in TLR patients.

Background: Recognition of the causes of early mortality after transvenous lead removal (TLR) is an essential step for the development of quality improvement programs. Objective: This study sought to determine the causes of early mortality after TLR and to further understand the circumstances surrounding death after TLR. Methods: We performed a retrospective analysis of all patients undergoing TLR from January 1, 2001, to January 1, 2021 at the Mayo Clinic (Rochester, Phoenix, and Jacksonville). Causes of death were identified through a detailed chart review of the electronic health record from within the Mayo Clinic system and outside records when available. The causes of death were further characterized based on whether it was related to the TLR procedure. Results: A total of 2,319 patients were included in the study. The overall 30-day all-cause mortality rate was 3%. Among all 30-day deaths, infection was the most common primary cause of death (42%). This was followed by decompensated heart failure (17%), procedure-related death (10%), sudden cardiac arrest (7%), and respiratory failure (6%). The 30-day mortality rate directly due to complications associated with the TLR procedure was 0.3% due to vascular tear and cardiac perforation. A third of deaths (33%) occurred after discharge from index hospitalization, among which 43% were readmitted before their death, 35% died at home or a nursing facility, and 22% were discharged on comfort care and died in hospice. The main reasons for readmission prior to death were sepsis and decompensated heart failure. Conclusions: The majority (90%) of 30-day mortality after TLR was not due to complications associated with TLR procedures. The primary causes were infection and decompensated heart failure. This highlights the importance of further research to reduce postoperative mortality from these factors, including deaths after hospital discharge.

Background: Recognition of the causes of early mortality after atrial fibrillation (AF) catheter ablation is essential for the improvement of patient safety. This study sought to determine the causes of early mortality (≤90 days) after AF ablation. 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 6723 patients were included in the study. The 90-day all-cause mortality rate was 0.22% (n=15). 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% (n=4). Conclusions: AF 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 low at 0.06%. Further studies are required to investigate causes and risk factors associated with sudden death in this patient population.

Abstract Primary cardiac sarcoma is a rare type of intracardiac mass. This report describes a patient with atrial flutter who had a new right atrial mass incidentally discovered on transesophageal echocardiography. A thrombus was suspected based on radiographic appearance, but there was minimal change with anticoagulation. The mass was resected and found to be an undifferentiated pleomorphic cardiac sarcoma, an uncommon sub-type within the already rare category of primary cardiac neoplasms. This report highlights the importance of considering primary malignancy and thoroughly correlating radiographic and clinical evidence during the diagnostic workup of patients with intracardiac masses.

AbstractObjectivesWe aimed to investigate the outcomes of pulmonary vein isolation in athletes.MethodsWe retrospectively identified endurance athletes who underwent catheter ablation at our institution (2004–2018). Endurance athletes were defined as participating in competitive athletics for at least 1500 lifetime hours in sports at the IB or IIA Bethesda classification or higher. Primary endpoints were freedom from atrial arrhythmias at 12, 24, and 36 months after the procedure. Secondary endpoints were defined as qualitative improvement in symptoms allowing athletes to return to their previous level of activity. Athletes were compared with a control group of nonathletes in a 3‐to‐1 matched analysis by age and sex.ResultsA total of 39 endurance athletes who underwent catheter ablation were identified during the study period. At 12 months, there was no difference in treatment outcomes for athletes versus nonathletes (relative risk [RR], 1.06; 95% CI, 0.92–1.22; p = .40). Freedom from atrial arrhythmias was 35% less likely in athletes than nonathletes at 24 months (RR, 0.65; 95% CI, 0.50–0.83; p < .001) and 42% less likely at 36 months (RR, 0.58; 95% CI, 0.41–0.79; p < .001). Overall, 77% of the athletes were able to return to their previous level of activity following catheter ablation.ConclusionEndurance athletes with atrial fibrillation appear to have higher rates of atrial arrhythmia recurrence than nonathletes after catheter ablation, with higher rates of atypical flutter. The majority of athletes were able to return to their previous level of activity after ablation.

Background: Cellular transplantation has emerged as promising approach for treating cardiac diseases. However, a poor engraftment rate limits our understanding on how transplanted cardiomyocytes contribute to cardiac function in the recipient’s heart. Methods: The CRISPR/Cas9 technique was employed for stable and constitutive gene expression in human-induced pluripotent stem-cell-derived cardiomyocytes (hiPSC-CMs). Myocardial infarction was induced in adult immunodeficient mice, followed by intramyocardial injection of hiPSC-CMs expressing either CCND2/channelrhodopsin 2 (hiPSC-CCND2OE/ChR2OECMs) or CCND2/luciferase (hiPSC-CCND2OE/LuciOECMs). Six months later, hemodynamics and intramural electrocardiogram were recorded upon blue light illuminations in anesthetized, open-chest mice. Results: Blue light resets automaticity of spontaneously beating hiPSC-CCND2OE/ChR2OECMs in culture, but not that of hiPSC-CCND2OE/LuciOECMs. Response to blue light was also observed in mice carrying large (>106 cells) intracardiac grafts of hiPSC-CCND2OE/ChR2OECM but not in mice carrying hiPSC-CCND2OE/LuciOECMs. The former exhibited single premature ventricular contractions upon light illumination or ventricular quadrigeminy upon second-long illuminations. At the onset of premature ventricular contractions, maximal systolic ventricular pressure decreased while ventricular volume rose concomitantly. Light-induced changes reversed upon resumption of sinus rhythm. Conclusions: We established an in vivo model for optogenetic-based modulation of the excitability of donor cardiomyocytes in a functional, reversible, and localized manner. This approach holds unique value for studying electromechanical coupling and molecular interactions between donor cardiomyocytes and recipient hearts in live animals.