Low mortality in SARS-CoV-2 infected heart transplant recipients at a single center.

Immunosuppressed heart transplant (HT) recipients are thought to be at higher risk of infection and mortality from SARS-CoV-2 infection coronavirus disease 2019 (COVID-19); however, evidence guiding management of HT patients are limited. Retrospective search of electronic health records from February 2020 to February 2021, identified 28 HT recipients out of 400 followed by UC San Diego who tested positive for SARS-CoV-2. Patient demographics, COVID-19 directed therapies, hospital course and outcomes were compared to control HT recipients who tested negative for SARS-CoV-2 during the same period (n = 80). Among 28 HT recipients who tested positive for SARS-CoV-2, 15 were admitted to the hospital and 13 were monitored closely as outpatients. Among inpatients, five developed severe illness and two died (7% mortality). Nine patients were treated with remdesivir, and four received dexamethasone and remdesivir. Two outpatients received neutralizing monoclonal antibody therapy and one outpatient received dexamethasone for persistent dyspnea. Immunosuppressed HT recipients, especially Hispanic patients and patients with higher body mass index, were at greater risk of infection and mortality from COVID-19 than the general population. Use of remdesivir and dexamethasone may have improved outcomes in our HT recipients compared to HT recipients at other centers.

Ablation of mitral annular flutter ablation utilizing a left atrial anterior line versus a lateral mitral isthmus line: a systematic review and meta-analysis.

PURPOSE: Mitral annular flutter (MAF) is a common arrhythmia after atrial fibrillation ablation. We sought to compare the efficacy and safety of catheter ablation utilizing either a left atrial anterior wall (LAAW) line or a lateral mitral isthmus (LMI) line. METHODS: We performed a systematic review for all studies that compared LAAW versus LMI lines. Risk ratio (RR) and mean difference (MD) 95% confidence intervals were measured for dichotomous and continuous variables, respectively. RESULTS: Four studies with a total of 594 patients were included, one of which was a randomized control trial. In the LMI ablation group, 40% of patients required CS ablation. There were no significant differences in bidirectional block (RR 1.26; 95% CI, 0.94-1.69) or ablation time (MD -1.5; 95% CI, -6.11-3.11), but LAAW ablation was associated with longer ablation line length (MD 11.42; 95% CI, 10.69-12.14) and longer LAA activation delay (MD 67.68; 95% CI, 33.47-101.89.14) when compared to LMI. There was no significant difference in pericardial effusions (RR 0.36; 95% CI, 0.39-20.75) between groups and more patients were maintained sinus rhythm (RR 1.19; 95% CI, 1.03-1.37, p = 0.02) who underwent LAAW compared to LMI. CONCLUSION: Ablation of mitral annular flutter with a LAAW line compared to a LMI line showed no difference in rates of acute bidirectional block, ablation time, or pericardial effusion. However, LAAW ablation required a longer ablation line length, resulted in greater LAA activation delayed and was associated with more sinus rhythm maintenance, with the added advantage of avoiding ablation in the CS.

Early Versus Delayed Lead Extraction in Patients With Infected Cardiovascular Implantable Electronic Devices.

OBJECTIVES: This study sought to assess the impact of early versus delayed lead extraction in patients with an infected cardiovascular implantable electronic device (CIED). BACKGROUND: CIED infections are associated with poor outcomes. Prior studies have demonstrated improved survival with CIED extraction compared with antibiotic therapy alone. The impact of timing of CIED extraction has not been well characterized. METHODS: All infected CIED extraction cases at our medical center from 2006 to 2019 were reviewed. Patients were divided into 2 groups based on the presence of bacteremia or isolated pocket infection. We assessed the in-hospital morbidity and 1-year mortality for early versus delayed lead extraction, using hospitalization day 7 as cutoff. RESULTS: Of 233 patients who underwent CIED extraction, 127 patients had bacteremia and 106 patients had pocket infection. Delayed extraction (15.2 days) in bacteremic patients was associated with septic shock (odds ratio [OR]: 5.39; 95% confidence interval [CI]: 1.23 to 23.67; p = 0.026), acute kidney injury (OR: 5.61; 95% CI: 2.15 to 14.63; p < 0.001), respiratory failure (OR: 5.52; 95% CI: 1.25 to 24.41; p = 0.024), and decompensated heart failure (OR: 3.32; 95% CI: 1.10 to 10.05; p = 0.033). Locally infected patients with delayed extraction (10.7 days) were associated with acute kidney injury (OR: 3.45; 95% CI: 1.11 to 10.77; p = 0.033) and respiratory failure (OR: 10.29; 95% CI: 1.26 to 83.93; p = 0.030). Delayed CIED extraction in both groups was associated with increased 1-year mortality. CONCLUSIONS: Delayed infected CIED extraction is associated with worse outcomes. This underscores the importance of early detection and a strategy for prompt management including lead extraction.

Association between implantable cardioverter-defibrillator and survival in patients awaiting heart transplantation: A meta-analysis and systematic review.

BACKGROUND: Patients with end-stage heart failure are at high risk for sudden cardiac death. However, implantable cardioverter-defibrillator (ICD) is not routinely implanted given the high competing risk of pump failure. A unique population worth separate consideration are patients with end-stage heart failure awaiting heart transplantation, as prolonged survival improves the chances of receiving transplant. OBJECTIVE: To compare clinical outcomes of heart failure patients with and without an ICD awaiting heart transplant. METHODS: We performed an extensive literature search and systematic review of studies that compared end-stage heart failure patients with and without an ICD awaiting heart transplantation. We separately assessed the rates of total mortality, sudden cardiac death, nonsudden cardiac death, and heart transplantation. Risk ratio (RR) and 95% confidence intervals were measured using the Mantel-Haenszel method. The random effects model was used owing to heterogeneity across study cohorts. RESULTS: Ten studies with a total of 36,112 patients were included. A total of 62.5% of patients had an ICD implanted. Patients with an ICD had decreased total mortality (RR 0.60, 95% CI 0.51-0.71, P < .00001) and sudden cardiac death (RR 0.27, 95% CI 0.11-0.66, P = .004) and increased rates of heart transplantation (RR 1.09, 95% CI 1.05-1.14, P < .0001). There was no difference in prevalence of nonsudden cardiac death (RR 0.68, 95% CI 0.44-1.04, P = .07). CONCLUSION: ICD implantation is associated with improved outcomes in patients awaiting heart transplant, characterized by decreased total mortality and sudden cardiac death as well as higher rates of heart transplantation.

Thromboembolism in Heart Failure Patients in Sinus Rhythm: Epidemiology, Pathophysiology, Clinical Trials, and Future Direction.

Despite advances in medical and device therapy, patients with heart failure remain at high risk for morbidity and mortality. Experimental and clinical studies have shown an association between heart failure and a hypercoagulable state, and that patients with heart failure experience an increased incidence of stroke and other thromboembolic events, regardless of whether they are in atrial fibrillation. Although oral anticoagulation is recommended when atrial fibrillation is present, the benefits of this therapy in patients with heart failure in sinus rhythm are uncertain. Older randomized controlled trials comparing warfarin with antiplatelet therapy were, for the most part, underpowered and failed to show convincing benefits of warfarin therapy in this population. Several recent studies that assessed the effects of low-dose direct-acting oral anticoagulant therapy in patients with coronary artery disease in sinus rhythm either included or specifically targeted patients with heart failure. Post hoc analysis of their results showed that this treatment strategy was associated with improved outcomes in patients with acute coronary syndrome or stable coronary artery disease and also a significant reduction in thromboembolic events, including ischemic stroke. This review presents the rationale for anticoagulant therapy in patients with heart failure in sinus rhythm, discusses gaps in our knowledge base, offers suggestions for when anticoagulation might be considered, and identifies potential directions for future research.

Linking Electrical Drivers With Atrial Cardiomyopathy for the Targeted Treatment of Atrial Fibrillation.

The relationship between atrial fibrillation (AF) and underlying functional and structural abnormalities has received substantial attention in the research literature over the past decade. Significant progress has been made in identifying these changes using non-invasive imaging, voltage mapping, and electrical recordings. Advances in computed tomography and cardiac magnetic resonance imaging can now provide insight regarding the presence and extent of cardiac fibrosis. Additionally, multiple technologies able to identify electrical targets during AF have emerged. However, an organized strategy to employ these resources in the targeted treatment of AF remains elusive. In this work, we will discuss the basis for mechanistic importance of atrial fibrosis and scar as potential sites promoting AF and emerging technologies to identify and target these structural and functional substrates in the electrophysiology laboratory. We also propose an approach to the use of such technologies to serve as a basis for ongoing work in the field.

Safety and Efficacy of Cardiovascular Implantable Electronic Device Extraction in Elderly Patients: A Meta-Analysis and Systematic Review.

BACKGROUND: Transvenous lead extraction of cardiovascular implantable electronic device (CIED) has been proven safe in the general patient population with the advances in extraction techniques. Octogenarians present a unique challenge given their comorbidities and the perceived increase in morbidity and mortality. OBJECTIVE: To assess the safety and outcomes of CIED extraction in octogenarians to younger patients. METHODS: We performed an extensive literature search and systematic review of studies that compared CIED extraction in octogenarians versus non-octogenarians. We separately assessed the rate of complete procedure success, clinical success, procedural mortality, major and minor complications. Risk ratio (RR) 95% confidence intervals were measured using the Mantel-Haenszel method. The random effects model was used due to heterogeneity across study cohorts. RESULTS: Seven studies with a total of 4,182 patients were included. There was no difference between octogenarians and non-octogenarians in complete procedure success (RR 1.01, 95% CI 1.00 - 1.02, p = 0.19) and clinical success (RR 1.01, 95% CI 1.00 - 1.01, p = 0.13). There was also no difference in procedural mortality (RR 1.43, 95% CI 0.46 - 4.39, p = 0.54), major complication (RR 1.40, 95% CI 0.68 - 2.88, p = 0.36), and minor complication (RR 1.43, 95% CI 0.90 - 2.29, p = 0.13). CONCLUSION: In this study, there was no evidence to suggest a difference in procedural success and complication rates between octogenarians and younger patients. Transvenous lead extraction can be performed safely and effectively in the elderly population.

Ventricular arrhythmias in patients with biventricular assist devices.

PURPOSE: Ventricular arrhythmias (VAs) are common in patients after left ventricular assist device (LVAD) implant and are associated with worse outcomes. However, the prevalence and impact of VA in patients with durable biventricular assist device (BIVAD) is unknown. We performed a retrospective cohort study of patients with BIVADs to evaluate the prevalence of VA and their clinical outcomes. METHODS: Consecutive patients who received a BIVAD between June 2014 and July 2017 at our medical center were included. The prevalence of VA, defined as sustained ventricular tachycardia or fibrillation requiring defibrillation or ICD therapy, was compared between BIVAD patients and a propensity-matched population of patients with LVAD from our center. The occurrence of adverse clinical events was compared between BIVAD patients with and without VA. RESULTS: Of the 13 patients with BIVADs, 6 patients (46%) experienced clinically significant VA, similar to a propensity-matched LVAD population (38%, p = 1.00). There were no differences in baseline characteristics between the two cohorts, except patients in the non-VA group who had worse hemodynamics (mitral regurgitation and right-sided indices), had less history of VA, and were younger. BIVAD patients with VA had a higher incidence of major bleeding (MR 3.05 (1.07-8.66), p = 0.036) and worse composite outcomes (log-rank test, p = 0.046). The presence of VA was associated with worse outcomes in both LVAD and BIVAD groups. CONCLUSIONS: Ventricular arrhythmias are common in patients with BIVADs and are associated with worse outcomes. Future work should assess whether therapies such as ablation improve the outcome of BIVAD patients with VA.

Role of adjunctive posterior wall isolation in patients undergoing atrial fibrillation ablation: a systematic review and meta-analysis.

BACKGROUND: The posterior wall of the left atrium may promote atrial fibrillation (AF) due to its propensity for fibrosis, in addition to a high prevalence of non-pulmonary vein triggers. Multiple smaller studies have assessed the incremental value of posterior wall isolation (PWI) in addition to standard atrial fibrillation. Similarly, this method has shown promise as an ablation strategy for patients with persistent AF, when PVI alone has shown only modest efficacy. METHODS: We performed an extensive literature search and systematic review of studies that compared AF ablation plus PWI versus control. We separately assessed the recurrence rates of all atrial arrhythmias (AF/AFL/AT), as well as separate recurrence rates of AF and atrial tachycardia/atrial flutter (AT/AFL) after ablation. Risk ratio (RR) 95% confidence intervals were measured using the Mantel-Haenszel method. The random effects model was used due to heterogeneity (I2) > 25%. RESULTS: Seven studies with a total of 1151 patients were included. Patients who underwent concomitant PWI experienced less recurrence of all atrial arrhythmias post ablation (RR 0.77; 95% CI 0.62-0.96, p = 0.02) and less recurrence of AF (RR 0.55; 95% CI 0.39-0.77, p < 0.01). There was no difference in onset of AT/AFL (RR 0.96; 95% CI 0.62-1.48, p = 0.85) after ablation. These results were replicated in subgroup analysis of patients with persistent AF. CONCLUSIONS: Based on the results of this meta-analysis, concomitant PWI is associated with less recurrence of AF and all atrial arrhythmias after ablation, without an increase in the risk for post-ablation AFL/AT.

Skin sympathetic nerve activity precedes the onset and termination of paroxysmal atrial tachycardia and fibrillation.

BACKGROUND: Skin sympathetic nerve activity (SKNA) is useful for estimating sympathetic tone in humans. OBJECTIVE: The purpose of this study was to test the hypotheses that (1) increased SKNA is associated with the onset and termination of paroxysmal atrial tachycardia (AT) and atrial fibrillation (AF) and (2) sinoatrial node response to SKNA is reduced in patients with more frequent AT or AF episodes. METHODS: SKNA and electrocardiogram were recorded in 11 patients (4 men and 7 women; average age 66 ± 10 years), including 3 patients with AT (11 ± 18 episodes per patient) and 8 patients with AF (24 ± 26 episodes per patient). RESULTS: The average SKNA (aSKNA) 10 seconds before AT onset was 1.07 ± 0.10 µV and 10 seconds after termination was 1.27 ± 0.10 µV; both were significantly (P = .032 and P < .0001) higher than that during sinus rhythm (0.97 ± 0.09 µV). The aSKNA 10 seconds before AF onset was 1.34 ± 0.07 µV and 10 seconds after termination was 1.31 ± 0.07 µV; both were significantly (P < .0001) higher than that during sinus rhythm (1.04 ± 0.07 µV). The aSKNA before onset (P < .0001) and after termination (P = .0011) was higher in AF than in AT. The sinus rate correlated (P < .0001) with aSKNA in each patient (average r = 0.74; 95% confidence interval 0.65-0.84). The r value in each patient negatively correlated with the number of AT and AF episodes (r = -0.6493; 95% confidence interval -0.8990 to -0.08073; P = .0306). CONCLUSION: Increased SKNA was observed both at the onset and termination of AT and AF. Patients with more frequent AT and AF episodes had a weak correlation between sinus rate and aSKNA, suggesting sinoatrial node remodeling by tachycardia.

Intermittent left cervical vagal nerve stimulation damages the stellate ganglia and reduces the ventricular rate during sustained atrial fibrillation in ambulatory dogs.

BACKGROUND: The effects of intermittent open-loop vagal nerve stimulation (VNS) on the ventricular rate (VR) during atrial fibrillation (AF) remain unclear. OBJECTIVE: The purpose of this study was to test the hypothesis that VNS damages the stellate ganglion (SG) and improves VR control during persistent AF. METHODS: We performed left cervical VNS in ambulatory dogs while recording the left SG nerve activity (SGNA) and vagal nerve activity. Tyrosine hydroxylase (TH) staining and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining were used to assess neuronal cell death in the SG. RESULTS: We induced persistent AF by atrial pacing in 6 dogs, followed by intermittent VNS with short ON-time (14 seconds) and long OFF-time (66 seconds). The integrated SGNA and VR during AF were 4.84 mV·s (95% confidence interval [CI] 3.08-6.60 mV·s) and 142 beats/min (95% CI 116-168 beats/min), respectively. During AF, VNS reduced the integrated SGNA and VR, respectively, to 3.74 mV·s (95% CI 2.27-5.20 mV·s; P = .021) and 115 beats/min (95% CI 96-134 beats/min; P = .016) during 66-second OFF-time and to 4.07 mV·s (95% CI 2.42-5.72 mV·s; P = .037) and 114 beats/min (95% CI 83-146 beats/min; P = .039) during 3-minute OFF-time. VNS increased the frequencies of prolonged (>3 seconds) pauses during AF. TH staining showed large confluent areas of damage in the left SG, characterized by pyknotic nuclei, reduced TH staining, increased percentage of TH-negative ganglion cells, and positive TUNEL staining. Occasional TUNEL-positive ganglion cells were also observed in the right SG. CONCLUSION: VNS damaged the SG, leading to reduced SGNA and better rate control during persistent AF.