Negative effects of COVID-19 on the implantation rate of cardiac resynchronization therapy with defibrillator device.

Introduction: COVID-19 drastically impacted the landscape of the United States' medical system. Limited data is available on the nationwide implantation trends in Cardiac Resynchronization Therapy Defibrillator (CRT-D) devices before and during the pandemic. We aimed to explore the impact of the COVID-19 pandemic on CRT-D insertion rates and adverse outcomes related to delays in care. Methods and Results: We conducted a retrospective cross-sectional analysis using the National Inpatient Sample database between 2017 and 2020. Variables were identified using their ICD-10 codes. Inclusion criteria: age ≥ 18 years, presenting for a nonelective admission, primary diagnosis of hypertensive heart disease, hypertensive heart, chronic kidney disease, or heart failure, and underwent insertion of a CRT-D. Between 2017 and 2020, CRT-D devices were inserted during 23,635 admissions. On average, 6198 devices were implanted yearly from 2017 to 2019, with only 5040 devices being implanted in 2020. Additionally, reduced implantation rates were noted for every cohort of hospital size, location, and teaching status during this year. The year 2020 also had the highest average death rate at 1.39%, but this difference was statistically insignificant (adjusted Wald test p = .767), and COVID-19 was not associated with an increased risk of inpatient mortality (OR 0.22, 95% CI 0.03-1.82, p = .162). Conclusion: The COVID-19 pandemic has affected all facets of the healthcare system, especially surgical volume rates. CRT-D procedures significantly decreased in 2020. This is the first retrospective study highlighting the trend of reduced rates of CRT-D implantation as a response to the COVID-19 pandemic.

Fatal ventricular arrhythmias in myocarditis: A review of current indications for defibrillator devices.

Historically, patients with myocarditis were considered for implantable cardioverter defibrillator (ICD) utilization only in the chronic phase of the disease following the development of persistent cardiomyopathy refractory to medical therapy or occurrence of a major ventricular arrhythmic event. However, recent literature has indicated that ventricular arrhythmias are frequently reported even in the acute phase of the disease, challenging the long-standing perception that this disease process was largely reversible. Given this changing environment of information, the latest US and European guidelines were recently updated in 2022 to now consider ICD implantation during the acute phase which has significantly increased the number of individuals eligible for these devices. Additionally, several studies with small subgroups of patients have demonstrated a possible benefit of wearable cardioverter defibrillators (WCDs) in this patient demographic. Assuming that larger studies confirm their utility, it is possible that WCDs can assist in detection of ventricular arrhythmias and selection of high-risk candidates for ICD implantation, while providing temporary protection for a small percentage of patients before the development of a major arrhythmic event. This review ultimately serves as a comprehensive review of the most recent guidelines for defibrillator use in acute and chronic myocarditis. OPINION STATEMENT: The latest US and European guidelines support ICD use for myocarditis patients following the development of persistent cardiomyopathy refractory to medical therapy or occurrence of a major ventricular arrhythmic event. Previously, patients in the acute phase were excluded from ICD utilization even after experiencing malignant ventricular tachycardia or ventricular fibrillation due to the long-standing perception that this disease process was largely reversible. However, recent literature has indicated that ventricular arrhythmias are frequently reported even in the acute phase of the disease. Additionally, we found that the myocardial damage that is inflicted persists many years after the initial episode. Given this changing environment of information, guidelines were recently updated in 2022 to now consider ICD implantation during the acute phase which has significantly increased the number of individuals eligible for these devices. We support possible ICD utilization for secondary prevention during the acute phase of myocarditis given the elevated risk of arrhythmia recurrence and the fact that any ventricular arrhythmia can induce sudden cardiac death. Future prospective studies are needed to assess which patients may benefit most from early ICD implantation. WCDs have improved survival in patient populations at high-risk for sudden cardiac death who are not candidates for ICD implantation. After analyzing several recent studies with small subgroups of patients, WCDs appear to demonstrate similar efficacy for myocarditis patients as well. Assuming that larger studies confirm their utility, we believe that WCDs can assist in detection of ventricular arrhythmias and selection of high-risk candidates for ICD implantation. Furthermore, WCDs have the additional benefit of acting as primary prevention by providing temporary protection for a small percentage of myocarditis patients before they develop a major arrhythmic event.

Clinical performance of implantable cardioverter-defibrillator lead monitoring diagnostics.

BACKGROUND: Implantable cardioverter-defibrillator (ICD) lead monitoring diagnostic alerts facilitate the diagnosis of structural lead failure. OBJECTIVE: The purpose of this study was to prospectively study the performance of Medtronic ICD lead monitoring alerts. METHODS: A prespecified ancillary substudy, World-Wide Randomized Antibiotic Envelope Infection Prevention Trial, was conducted in patients with an ICD with all available alerts enabled. The investigators reported possible lead system events (LSEs), with or without an alert. An independent committee reviewed all data and classified events as lead failure, other LSE, or nonlead system events (NLEs). RESULTS: In 4942 patients who were followed for 19.4 ± 8.7 months, there were 124 alerts (65 LSEs, 59 NLEs) and 19 LSEs without an alert. Lead monitoring alerts had 100% sensitivity for the 48 adjudicated lead failures (95% confidence interval 92.6%-100%) and for 10 events adjudicated as either lead failure or connection issue. The positive predictive value of alerts for lead failure was 38.7% (48 of 124). For 34 pace-sense lead failures, an alert that incorporated oversensing was more sensitive than the pacing impedance threshold alert (33 patients [97.1%] vs 9 patients [26.5%]; P < .0001). However, the sensitivity was only 13.6% for lead dislodgments or perforations. Inappropriate shocks occurred in 2 patients with pace-sense lead failure (5.9%). No patient had unnecessary lead replacement for any of the NLEs. CONCLUSION: In this first real-world prospective study, lead monitoring alerts had 100% sensitivity for identifying lead failures. Although their positive predictive value was modest, no false-positive alerts resulted in an unnecessary lead replacement. For the diagnosis of pace-sense lead failure, an alert for oversensing was more sensitive than a pacing impedance threshold alert. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02277990.

Heart Block Caused by Ticagrelor Use in a Patient Who Underwent Adenosine Diastolic Fractional Reserve Assessment: A Case Report.

Ticagrelor is a direct and rapid-acting antagonist of the P2Y12-adenosine diphosphate receptor found on platelets. The drug is recommended as a first-line antiplatelet agent in patients with acute coronary syndromes, as evidenced in its superiority compared to clopidogrel according to the Platelet Inhibition and Patient Outcomes study. Specifically, the mechanism of action has been proven to show higher inhibition and less variability in its action on P2Y12 receptors compared to clopidogrel. Additionally, ticagrelor inhibits the equilibrative nucleoside transporter 1 adenosine transporter protein leading to an increased concentration of adenosine in the blood, particularly at sites of ischemia. This effect increases the biological efficacy of ticagrelor in terms of cardioprotection, anticoagulation effects, and anti-inflammatory effects. However, the effects are also thought to be responsible for some of the adverse pharmacological effects reported with ticagrelor, such as bradycardia and ventricular pauses > 3 seconds. Herein, we report a case of recurrent sinus arrest and ventricular asystole in a patient pre-treated with ticagrelor and subsequent physiological assessment of a coronary lesion with fractional flow reserve using intravenous adenosine infusion.

Complete Pocket Resection with Regional Flap Closure for Treatment of Cardiac Implantable Device Infections.

BACKGROUND: Cardiac implantable electronic device infections are associated with substantial morbidity and mortality. There are varied recommendations in the literature about treatment of the wound after extraction of all hardware, but only conservative, time-consuming approaches such as open packing and negative-pressure therapy along with a long interval before reimplanting any hardware have generally been recommended for the treatment.1-4. METHODS: A retrospective review was performed of 42 patients treated at Jersey Shore University Medical Center for implantable cardioverter defibrillator and permanent pacemaker infections between July 2010 and April 2018 with an aggressive, multidisciplinary approach utilizing an invasive cardiologist and a plastic surgeon. Clinical and demographic data were collected, and a descriptive analysis was conducted. RESULTS: A total of 42 patients, with a median age of 76 years, were selected for our treatment of pacemaker pocket infection. Patients underwent removal of all hardware followed by debridement and flap closure of the wound soon after extraction. Reimplantation was performed when indicated typically within a week after initial extraction and typically on the contralateral side. There were no reports of reinfection and no mortality in all 42 patients treated. CONCLUSION: We found that the aggressive removal of all hardware and excisional debridement of the entire capsule followed by flap coverage and closure of the wound allowed for a shortened interval to reimplantation with no ipsilateral or contralateral infections during the follow-up period.

Advantage of optimizing V-V timing in cardiac resynchronization therapy devices.

BACKGROUND: There is little consensus as to the benefits of interventricular (V-V) timing optimization in cardiac resynchronization therapy (CRT). A variety of parameters are currently used to optimize device timing. This study was designed to investigate the potential advantage of using 3D ejection fraction (EF) and aortic velocity-time integral (VTI) as measures of global left ventricular (LV) function to optimize ventricular activation in CRT devices. METHODS: Seventy-four patients seen in the Optimization Clinic with adequate echocardiographic images were included. Three aortic VTI and two 3D EF values were recorded at five V-V settings and the average value used. Aortic VTI and 3D EF were classified as the best, worst, and simultaneous setting values. Data were analyzed using a two-tailed paired t-test. RESULTS: Comparing the best to worst V-V timing settings, VTI improved by 4.7 ± 7.5 cm (P < 0.0001) and 3D EF by 9.9%± 5.7% (P < 0.0001). Comparing the simultaneous setting to the best V-V timing setting, VTI improved by 2.4 ± 2.1 cm (P < 0.0001) and 3D EF by 3.8%± 4.9% (P < 0.0001). Aortic VTI improved in 85% of patients and 3D EF improved in 72%. However, only 26% of the patients had the same optimal setting using aortic VTI and 3D EF yielding an r(2) value of 0.003. CONCLUSIONS: Individualized echocardiographic V-V optimization of CRT devices improves global LV function as measured by aortic VTI and 3D EF. Substantial differences in function were seen over an 80-ms range of V-V timing and optimization resulted in improved LV function in the majority of patients.

Transfemoral snaring and stabilization of pacemaker and defibrillator leads to maintain vascular access during lead extraction.

BACKGROUND: Lead extraction is an effective method for removing pacemaker and defibrillator leads and to obtain venous access when central veins are occluded. OBJECTIVE: We report a series of patients who required lead extraction and preservation of vascular access requiring a vascular snare introduced from the femoral vein to provide traction on the lead. This technique allowed advancement of the extraction sheath beyond the level of vascular occlusion, preserving vascular access in all patients. METHODS: All patients had peripheral contrast venography performed immediately prior to the procedure to identify the site(s) of venous occlusion. An extraction sheath was employed and with direct manual traction, the lead tip pulled free from the myocardial surface prior to advancement of the sheath beyond the occlusion. A transfemoral snare was used to grasp the distal portion of the lead and traction was used to immobilize the lead. RESULTS: In all patients, transfemoral snaring of the leads was necessary to allow safe advancement of a sheath to open the occluded venous system. There were no complications in any of the patients. CONCLUSION: Our series demonstrates the simple and safe technique of transfemoral lead snaring to assist lead extraction and maintain vascular access in the setting of venous occlusion, when the distal lead tip pulls free of the myocardium before an extraction sheath is passed beyond the point of venous obstruction.

Lack of clinical predictors of optimal V-V delay in patients with cardiac resynchronization devices.

INTRODUCTION: Cardiac resynchronization therapy (CRT) is a well-established therapy for patients with moderate-to-severe heart failure (HF), left ventricular dysfunction with an ejection fraction or=130 msec. Device optimization is often performed, adjusting the timing of RV and LV stimulation to produce a pacing sequence that yields the best global cardiac performance. However, no standard guidelines exist for optimization and many invasive and non-invasive techniques have been employed with mixed results. The aim of the present study was to determine whether there are any clinical predictors of the optimal V-V settings in patients implanted with CRT devices. METHODS AND RESULTS: We prospectively evaluated 47 consecutive patients with HF who were referred to our device optimization clinic. The mean patient age was 64.9 +/- 12.7 years. Patients were in both sinus rhythm (83%) and atrial fibrillation. Prior to device implant, 51% of patients had left bundle branch block (LBBB), 17% had intra-ventricular conduction delay (IVCD) and 21% were RV paced. Sixty-two percent were male, the mean QRS duration was 152 +/- 29 ms, mean LVEF 26 +/- 8% and 60% had a non-ischemic cardiomyopathy. Overall, 82% of patients required sequential pacing with 69% requiring LV pre-excitation to produce the best global cardiac function as determined by aortic velocity time integrals (VTI). In our cohort, none of the clinical characteristics evaluated, including etiology of the cardiomyopathy, QRS duration, LVEF, pre-implant rhythm or AV delay were predictive of an optimal simultaneous or sequential V-V setting. CONCLUSIONS: None of the clinical variables tested in our analysis predicted optimal RV-LV settings. Our results suggest that individual optimization and programming of V-V settings is necessary. The inability to predict optimal settings likely reflects the unique characteristics of each patient and supports the need for individualized programming of each device.

The inoperable valvular heart disease patient:the pluses and minuses of percutaneous valvular replacement.

The spectrum of potentially successful treatment options for inoperable valvular disease is limited. Aortic valvuloplasty may offer temporary improvement in symptoms and some survival benefit in select non-surgical patients with aortic stenosis, but it does not improve long-term outcome. Mitral valve incompetence often responds well to surgical repair, though patients with significantly reduced left ventricular function have worsened outcomes. The design of a percutaneous implantable prosthetic heart valve is a promising alternative to valvuloplasty. Although not yet an established interventional method, Percutaneous Aortic Valve Replacement (PAVR) will likely take a position among the innovative catheter-based techniques currently in development. The appropriate clinical scenario for Percutaneous Mitral Valve Intervention (PMVI), however, may be significantly narrower. As with many other minimally invasive operations or procedures, the ethical considerations of a novel approach must be considered.

Effect of kidney transplantation on left ventricular systolic dysfunction and congestive heart failure in patients with end-stage renal disease.

OBJECTIVES: We examined the impact of kidney transplantation on left ventricular ejection fraction (LVEF) in end-stage renal disease (ESRD) patients with congestive heart failure (CHF). BACKGROUND: The ESRD patients with decreased LVEF and a poor New York Heart Association (NYHA) functional class are not usually referred for transplant evaluations, as they are considered to be at increased risk of cardiac and surgical complications. METHODS: Between June 1998 and November 2002, 103 recipients with LVEF < or =40% and CHF underwent kidney transplantation. The LVEF was re-assessed by radionuclide ventriculography gated-blood pool (MUGA) scan at six and 12 months and at the last follow-up during the post-transplant period. RESULTS: Mean pre-transplant LVEF% increased from 31.6 +/- 6.7 (95% confidence interval [CI] 30.3 to 32.9) to 52.2 +/- 12.0 (95% CI 49.9 to 54.6, p = 0.002) at 12 months after transplantation. There was no perioperative death. After transplantation, 69.9% of patients achieved LVEF > or =50% (normal LVEF). A longer duration of dialysis (in months) before transplantation decreased the likelihood of normalization of LVEF in the post-transplant period (odds ratio 0.82, 95% CI 0.74 to 0.91; p < 0.001). The NYHA functional class improved significantly in those with normalization of LVEF (p = 0.003). After transplantation, LVEF >50% was the only significant factor associated with a lower hazard for death or hospitalizations for CHF (relative risk 0.90, 95% CI 0.86 to 0.95; p < 0.0001). CONCLUSIONS: Kidney transplantation in ESRD patients with advanced systolic heart failure results in an increase in LVEF, improves functional status of CHF, and increases survival. To abrogate the adverse effects of prolonged dialysis on myocardial function, ESRD patients should be counseled for kidney transplantation as soon as the diagnosis of systolic heart failure is established.