First human safety and effectiveness study of defibrillation with a novel patch wearable cardioverter-defibrillator.

AIMS: Wearable cardioverter-defibrillators (WCDs) are indicated in patients at risk of sudden cardiac arrest who are not immediate candidates for implantable defibrillator therapy. Limitations of existing WCDs include poor compliance and high false alarm rates. The Jewel is a novel patch-WCD (P-WCD) that addresses these limitations with an adhesive-based design for near-continuous wear and a machine learning algorithm designed to minimize inappropriate detections. This was a first-in-human study of the Jewel P-WCD conducted in an electrophysiology (EP) lab to determine the safety and effectiveness of the device in terminating ventricular tachycardia/ventricular fibrillation (VT/VF) with a single shock. The aim was to evaluate the safety and effectiveness of terminating VT/VF with a single shock using the Jewel P-WCD. METHODS AND RESULTS: This was a first-in-human, prospective, single-arm, single-centre study in patients scheduled for an EP procedure in which VT/VF was expected to either spontaneously occur or be induced. The Jewel P-WCD was placed on consented patients; upon confirmation of VT/VF, a single shock (150 J) was delivered via the device. A group sequential design and Pocock alpha spending function was used to measure the observed proportion of successful VT/VF single-shock terminations. The endpoint was achieved if the lower confidence limit exceeded the performance goal of 62%, using a one-sided lower 97.4% exact confidence bound. Of 18 eligible subjects, 16 (88.9%, 97.4% confidence bound: 65.4%) were successfully defibrillated with a single shock, exceeding the primary endpoint performance goal with no adverse events. CONCLUSION: This first-in-human evaluation of the Jewel P-WCD demonstrated the safety and effectiveness of terminating VT/VF. CLINICAL TRIAL REGISTRATION: URL: https://clinicaltrials.gov/; Unique identifier: NCT05490459.

Coronary Arterial Spasm During Pulsed Field Ablation to Treat Atrial Fibrillation.

BACKGROUND: Pulsed field ablation (PFA) has a unique safety profile when used to treat atrial fibrillation, largely related to its preferentiality for myocardial tissue ablation, in particular, esophageal sparing. A pentaspline catheter was the first such PFA system studied clinically for atrial fibrillation ablation; in these initial regulatory trials, the catheter was used for pulmonary vein isolation and left atrial posterior wall ablation. Since its regulatory approval in Europe, in clinical practice, physicians have ablated beyond pulmonary vein isolation and left atrial posterior wall ablation to expanded lesion sets in closer proximity to coronary arteries. This is an unstudied important issue because preclinical and clinical data have raised the potential for coronary arterial spasm. Herein, we studied the vasospastic potential of PFA lesion sets, both remote from and adjacent to coronary arteries. METHODS: During routine atrial fibrillation ablation using the pentaspline PFA catheter, coronary angiography was performed before, during, and after pulsed field applications. The lesion sets studied included: (1) those remote from the coronary arteries such as pulmonary vein isolation (n=25 patients) and left atrial posterior wall ablation (n=5), and (2) ablation of the cavotricuspid isthmus (n=20) that is situated adjacent to the right coronary artery. RESULTS: During pulmonary vein isolation and left atrial posterior wall ablation, coronary spasm did not occur, but cavotricuspid isthmus ablation provoked severe subtotal vasospasm in 5 of 5 (100%) consecutive patients, and this was relieved by intracoronary nitroglycerin in 5.5±3.5 minutes. ST-segment elevation was not observed. However, no patient (0%, P=0.004) had severe spasm if first administered parenteral nitroglycerin, either intracoronary (n=5) or intravenous (n=10), before treatment. CONCLUSIONS: Coronary vasospasm was not provoked during PFA at locations remote from coronary arteries, but when the energy is delivered adjacent to a coronary artery, PFA routinely provokes subclinical vasospasm. This phenomenon is attenuated by nitroglycerin, administered either post hoc to treat spasm or as prophylaxis.

Nonprocedural bleeding after left atrial appendage closure versus direct oral anticoagulants: A subanalysis of the randomized PRAGUE-17 trial.

INTRODUCTION: Observational studies have shown low bleeding rates in patients with atrial fibrillation (AF) treated by left atrial appendage closure (LAAC); however, data from randomized studies are lacking. This study compared bleeding events among patients with AF treated by LAAC and nonvitamin K anticoagulants (NOAC). METHODS: The Prague-17 trial was a prospective, multicenter, randomized trial that compared LAAC to NOAC in high-risk AF patients. The primary endpoint was a composite of a cardioembolic event, cardiovascular death, and major and clinically relevant nonmajor bleeding (CRNMB) defined according to the International Society on Thrombosis and Hemostasis (ISTH). RESULTS: The trial enrolled 402 patients (201 per arm), and the median follow-up was 3.5 (IQR 2.6-4.2) years. Bleeding occurred in 24 patients (29 events) and 32 patients (40 events) in the LAAC and NOAC groups, respectively. Six of the LAAC bleeding events were procedure/device-related. In the primary intention-to-treat analysis, LAAC was associated with similar rates of ISTH major or CRNMB (sHR 0.75, 95% CI 0.44-1.27, p = 0.28), but with a reduction in nonprocedural major or CRNMB (sHR 0.55, 95% CI 0.31-0.97, p = 0.039). This reduction for nonprocedural bleeding with LAAC was mainly driven by a reduced rate of CRNMB (sHR for major bleeding 0.69, 95% CI 0.34-1.39, p = .30; sHR for CRNMB 0.43, 95% CI 0.18-1.03, p = 0.059). History of bleeding was a predictor of bleeding during follow-up. Gastrointestinal bleeding was the most common bleeding site in both groups. CONCLUSION: During the 4-year follow-up, LAAC was associated with less nonprocedural bleeding. The reduction is mainly driven by a decrease in CRNMB.

Quantification of artifacts during cardiac magnetic resonance in patients with leadless Micra pacemakers.

INTRODUCTION: When cardiac magnetic resonance (MR) is performed after previous leadless transcatheter pacemaker implantation, an image distortion has to be expected in the heart region and evaluation of myocardial tissue can be affected. In this clinical prospective study, we aim to assess the extent and impact of this artifact on individual ventricular segments and compare it to conventional pacing devices. METHODS: Total of 20 patients with leadless pacemaker placed in the right ventricle underwent cardiac MR imaging in a 1.5 Tesla scanner. A multiplanar segmentation was used to demarcate the left and right ventricular myocardium as well as the pacemaker-caused image artifact in systolic and diastolic time frames. Artifact size and its relative influence on myocardial segments were quantitatively assessed and expressed in AHA-17 model. RESULTS: Implanted leadless pacemaker caused an image artifact with a volume of 48 ± 5 ml. Most distorted were the apical septal (53 ± 23%), apical inferior (30 ± 18%), and midventricular inferoseptal (30 ± 20%) segments. The artifact intersection with basal and lateral segments was none or negligible (up to 2%). The portion of left ventricular (LV) myocardium affected by the artifact was significantly higher in systole (8 ± 4%) compared to diastole (10 ± 3%; p < .001). CONCLUSION: Implantation of leadless pacemaker represents no obstacle for cardiac MR imaging but causes an image artifact located mostly in septal, inferoseptal, and anteroseptal segments of apical and midventricular LV myocardium. With the exception of the apex, diastolic timing reduces the image distortion of all segments and improves global ventricular assessment.

The effect of left atrial appendage closure on heart failure biomarkers: A PRAGUE-17 trial subanalysis.

INTRODUCTION: The randomized PRAGUE-17 trial demonstrated noninferiority of left atrial appendage closure (LAAC) to non-vitamin K anticoagulants (NOACs) for the prevention of major cardiovascular or cerebrovascular events. However, the left atrial appendage is an important source of natriuretic peptides and plays a role in left atrial reservoir function. Changes of heart failure (HF) biomarkers after LAAC compared to NOAC has not been studied. The aim of the study was to compare the changes in concentrations of HF biomarkers between LAAC and NOAC patients. METHODS: Of 402 patients randomized in the PRAGUE-17 trial, biomarkers were analyzed in 144 patients (73 in the NOAC and 71 in the LAAC group). Both groups had similar baseline characteristics. Serum concentration of NT-proBNP, NT-proANP, Galectin-3, and GDF-15 were measured at baseline (before the procedure in the LAAC group), at the 6-month (and at 24-month for NT-proBNP) follow-up timepoint. RESULTS: There were no significant differences in baseline, 6 month, and delta (δ = baseline - 6 month) concentrations of NT-proANP between the groups (NOAC: baseline 2.6 [0.5; 4.9], 6-month 3.1 [1.8; 4.8], p = .068; LAAC: baseline 3.3 [1.1; 4.6], 6-month 2.6 [0.9; 5.3], p = .51; p value for δ in concentrations between groups = 0.42). Similarly, there were no significant differences in baseline, 6, 24 months, and delta concentrations of NT-proBNP between the groups (NOAC: baseline 461.0 [113.5; 1342.0], 6 month 440.0 [120.5; 1291.5], 24 month 798 [274; 2236], p = .39; LAAC: baseline 421.0 [100.0; 1320.0], 6 month 601.0 [145.0; 1230.0], 24 month 855 [410; 1367], p = .28; p value for δ in concentrations between groups = 0.73 at 6 months, and 0.58 at 24 months). Finally, no significant differences were present in baseline, 6 month, and δ concentrations of Galectin-3 and GDF-15 between the two groups. CONCLUSION: LAAC did not significantly influence the levels of HF biomarkers 6 months after the procedure.

Intracardiac echocardiography-guided implantation of the Watchman FLX left atrial appendage closure device.

BACKGROUND: The next-generation Watchman FLX left atrial appendage closure (LAAC) device has: (1) an atraumatic closed distal end, (2) reduced height, (3) a recessed screw hub to decrease device-related thrombus (DRT), (4) two rows of J-shape anchors so redeployment is possible after full recapture, and (5) ability to treat a greater size range of LAA ostia. OBJECTIVE: To report, for the first time, the feasibility and safety of intracardiac echocardiography (ICE)-guided Watchman FLX implantation. METHODS: A single-center prospective registry of atrial fibrillation patients planned for LAAC with the FLX device underwent ICE-guided implantation with conscious sedation. Transesophageal echocardiography (TEE) imaging was done preprocedure (to assess LAA size and exclude thrombus) and at clinical follow-up at 6-12 weeks. Clinical outcomes were LAA closure success, complications, leak, or DRT on follow-up TEE and major safety events. RESULTS: The study included 30 patients: age 75 ± 8 years, 53% men, CHA2 DS2 -VASc 4.6 ± 1.6, and HAS-BLED 3.4 ± 1.1. The primary indication was prior bleeding in 60% (72% GI bleeding). The LAA orifice width and length were 22.7 ± 3.1 and 25.7 ± 5.7 mm, respectively. Technical success was 100% (the first-choice device was used in 28 of 30). Procedure time was less than 30 min in 27 of 30 cases, with 36 ± 15 ml contrast used. The final device size was 29.2 ± 4.7 mm with 21.6 ± 4.5% compression. There were no procedure-related complications. Follow-up TEE at a median 47 days follow-up showed 100% device success with no DRT or peridevice leak ≥5 mm. Major safety events occurred in 6.6% (2/30). CONCLUSION: The Watchman FLX device can be safely implanted with intraprocedural ICE imaging instead of TEE.

Increasing venoarterial extracorporeal membrane oxygenation flow puts higher demands on left ventricular work in a porcine model of chronic heart failure.

BACKGROUND: Venoarterial extracorporeal membrane oxygenation (VA ECMO) is widely used in the treatment of circulatory failure, but repeatedly, its negative effects on the left ventricle (LV) have been observed. The purpose of this study is to assess the influence of increasing extracorporeal blood flow (EBF) on LV performance during VA ECMO therapy of decompensated chronic heart failure. METHODS: A porcine model of low-output chronic heart failure was developed by long-term fast cardiac pacing. Subsequently, under total anesthesia and artificial ventilation, VA ECMO was introduced to a total of five swine with profound signs of chronic cardiac decompensation. LV performance and organ specific parameters were recorded at different levels of EBF using a pulmonary artery catheter, a pressure-volume loop catheter positioned in the LV, and arterial flow probes on systemic arteries. RESULTS: Tachycardia-induced cardiomyopathy led to decompensated chronic heart failure with mean cardiac output of 2.9 ± 0.4 L/min, severe LV dilation, and systemic hypoperfusion. By increasing the EBF from minimal flow to 5 L/min, we observed a gradual increase of LV peak pressure from 49 ± 15 to 73 ± 11 mmHg (P = 0.001) and an improvement in organ perfusion. On the other hand, cardiac performance parameters revealed higher demands put on LV function: LV end-diastolic pressure increased from 7 ± 2 to 15 ± 3 mmHg, end-diastolic volume increased from 189 ± 26 to 218 ± 30 mL, end-systolic volume increased from 139 ± 17 to 167 ± 15 mL (all P < 0.001), and stroke work increased from 1434 ± 941 to 1892 ± 1036 mmHg*mL (P < 0.05). LV ejection fraction and isovolumetric contractility index did not change significantly. CONCLUSIONS: In decompensated chronic heart failure, excessive VA ECMO flow increases demands and has negative effects on the workload of LV. To protect the myocardium from harm, VA ECMO flow should be adjusted with respect to not only systemic perfusion, but also to LV parameters.

Interventional left atrial appendage closure vs novel anticoagulation agents in patients with atrial fibrillation indicated for long-term anticoagulation (PRAGUE-17 study).

Atrial fibrillation (AF), with a prevalence of 1% to 2%, is the most common cardiac arrhythmia. Without antithrombotic treatment, the annual risk of a cardioembolic event is 5% to 6%. The source of a cardioembolic event is a thrombus, which is usually formed in the left atrial appendage (LAA). Prevention of cardioembolic events involves treatment with anticoagulant drugs: either vitamin K antagonists or, recently, novel oral anticoagulants (NOAC). The other (nonpharmacologic) option for the prevention of a cardioembolic event involves interventional occlusion of the LAA. OBJECTIVE: To determine whether percutaneous LAA occlusion is noninferior to treatment with NOAC in AF patients indicated for long-term systemic anticoagulation. STUDY DESIGN: The trial will be a prospective, multicenter, randomized noninferiority trial comparing 2 treatment strategies in moderate to high-risk AF patients (ie, patients with history of significant bleeding, or history of cardiovascular event(s), or a with CHA2DS2VASc ≥3 and HAS-BLED score ≥2). Patients will be randomized into a percutaneous LAA occlusion (group A) or a NOAC treatment (group B) in a 1:1 ratio; the randomization was done using Web-based randomization software. A total of 396 study participants (198 patients in each group) will be enrolled in the study. The primary end point will be the occurrence of any of the following events within 24months after randomization: stroke or transient ischemic attack (any type), systemic cardioembolic event, clinically significant bleeding, cardiovascular death, or a significant periprocedural or device-related complications. CONCLUSION: The PRAGUE-17 trial will determine if LAA occlusion is noninferior to treatment with NOAC in moderate- to high-risk AF patients.

Inducibility of ventricular fibrillation during mild therapeutic hypothermia: electrophysiological study in a swine model.

INTRODUCTION: Mild therapeutic hypothermia (MTH) is being used after cardiac arrest for its expected improvement in neurological outcome. Safety of MTH concerning inducibility of malignant arrhythmias has not been satisfactorily demonstrated. This study compares inducibility of ventricular fibrillation (VF) before and after induction of MTH in a whole body swine model and evaluates possible interaction with changing potassium plasma levels. METHODS: The extracorporeal cooling was introduced in fully anesthetized swine (n = 6) to provide MTH. Inducibility of VF was studied by programmed ventricular stimulation three times in each animal under the following: during normothermia (NT), after reaching the core temperature of 32°C (HT) and after another 60 minutes of stable hypothermia (HT60). Inducibility of VF, effective refractory period of the ventricles (ERP), QTc interval and potassium plasma levels were measured. RESULTS: Starting at normothermia of 38.7 (IQR 38.2; 39.8)°C, HT was achieved within 54 (39; 59) minutes and the core temperature was further maintained constant. Overall, the inducibility of VF was 100% (18/18 attempts) at NT, 83% (15/18) after reaching HT (P = 0.23) and 39% (7/18) at HT60 (P = 0.0001) using the same protocol. Similarly, ERP prolonged from 140 (130; 150) ms at NT to 206 (190; 220) ms when reaching HT (P < 0.001) and remained 206 (193; 220) ms at HT60. QTc interval was inversely proportional to the core temperature and extended from 376 (362; 395) at NT to 570 (545; 599) ms at HT. Potassium plasma level changed spontaneously: decreased during cooling from 4.1 (3.9; 4.8) to 3.7 (3.4; 4.1) mmol/L at HT (P < 0.01), then began to increase and returned to baseline level at HT60 (4.6 (4.4; 5.0) mmol/L, P = NS). CONCLUSIONS: According to our swine model, MTH does not increase the risk of VF induction by ventricular pacing in healthy hearts. Moreover, when combined with normokalemia, MTH exerts an antiarrhythmic effect despite prolonged QTc interval.

Increasing venoarterial extracorporeal membrane oxygenation flow negatively affects left ventricular performance in a porcine model of cardiogenic shock.

BACKGROUND: The aim of this study was to assess the relationship between extracorporeal blood flow (EBF) and left ventricular (LV) performance during venoarterial extracorporeal membrane oxygenation (VA ECMO) therapy. METHODS: Five swine (body weight 45 kg) underwent VA ECMO implantation under general anesthesia and artificial ventilation. Subsequently, acute cardiogenic shock with signs of tissue hypoxia was induced. Hemodynamic and cardiac performance parameters were then measured at different levels of EBF (ranging from 1 to 5 L/min) using arterial and venous catheters, a pulmonary artery catheter and a pressure-volume loop catheter introduced into the left ventricle. RESULTS: Myocardial hypoxia resulted in a decline in mean (±SEM) cardiac output to 2.8 ± 0.3 L/min and systolic blood pressure (SBP) to 60 ± 7 mmHg. With an increase in EBF from 1 to 5 L/min, SBP increased to 97 ± 8 mmHg (P < 0.001); however, increasing EBF from 1 to 5 L/min significantly negatively influences several cardiac performance parameters: cardiac output decreased form 2.8 ± 0.3 L/min to 1.86 ± 0.53 L/min (P < 0.001), LV end-systolic volume increased from 64 ± 11 mL to 83 ± 14 mL (P < 0.001), LV stroke volume decreased from 48 ± 9 mL to 40 ± 8 mL (P = 0.045), LV ejection fraction decreased from 43 ± 3 % to 32 ± 3 % (P < 0.001) and stroke work increased from 2096 ± 342 mmHg mL to 3031 ± 404 mmHg mL (P < 0.001). LV end-diastolic pressure and volume were not significantly affected. CONCLUSIONS: The results of the present study indicate that higher levels of VA ECMO blood flow in cardiogenic shock may negatively affect LV function. Therefore, it appears that to mitigate negative effects on LV function, optimal VA ECMO blood flow should be set as low as possible to allow adequate tissue perfusion.

Acute and long-term results with the 3rd generation visually guided laser balloon ablation system for pv isolation.

BACKGROUND: Visually guided laser balloon ablation is known as an effective pulmonary vein (PV) isolation device. The third-generation laser balloon ablation system (X3) equipped with compliant balloon and an automated motor-driven laser output mechanism, namely RAPID mode, has been clinically proven for PV isolation. METHODS: PV isolation with X3 was performed in all the patients with paroxysmal and early-stage persistent atrial fibrillation (AF). Acute data for PV isolation and clinical outcomes including supraventricular tachyarrhythmia (SVT: AF, atrial flutter, or atrial tachycardia)-free survival rate beyond 1 year were analyzed. RESULTS: A total of 110 patients (62 ± 13 years old, 80% of paroxysmal AF) were treated with X3. RAPID mode with was utilized to achieve PV isolation in all cases. In combination with RAPID mode and spot mode laser ablation, 91.1% (380/417) of veins were isolated on the first circumferential lesion set and did not require touch-up ablation and during the index procedure 100% of attempted veins were isolated. The mean procedure time was 77.0 ± 22.7 min and LA dwell time was 61.9 ± 22.0 min. Total duration of laser application was 5.1 ± 2.3 min per vein. At 1 year, SVT-free survival rate was 93.7% in paroxysmal AF patients, and 81.1% in persistent AF patients. CONCLUSIONS: A novel continuous automatic laser balloon ablation system was proved to be safe and effective for both paroxysmal and persistent AF patients. The clinical result demonstrated that PV isolation with X3 could achieve a high SVT-free survival rate.

Coronary Artery Spasm During Pulsed Field vs Radiofrequency Catheter Ablation of the Mitral Isthmus.

Importance: In treating atrial fibrillation, pulsed field ablation (PFA) is a novel energy modality with comparable efficacy to conventional thermal ablation, such as radiofrequency ablation (RFA), but with the benefit of some preferentiality to myocardial tissue ablation. Studies have demonstrated important safety advantages, including the absence of esophageal injury or pulmonary vein stenosis and only rare phrenic nerve injury. However, there is emerging evidence of coronary artery vasospasm provoked by PFA. Objective: To compare the incidence and severity of left circumflex arterial vasospasm between PFA and RFA during adjacent ablation along the mitral isthmus. Design, Setting, and Participants: This prospective cohort study enrolled consecutive adult patients receiving first-ever PFA or RFA of the mitral isthmus during catheter ablation of atrial fibrillation in 2022 with acute follow-up at a single referral European center. Exposure: A posterolateral mitral isthmus line was created using either a multielectrode pentaspline PFA catheter (endocardial ablation) or a saline-irrigated RFA catheter. Simultaneous diagnostic coronary angiography was performed before, during, and after catheter ablation. Nitroglycerin was planned for spasm persisting beyond 20 minutes or for significant electrocardiographic changes. Main Outcomes and Measures: The frequency and severity of left circumflex arterial vasospasm was assessed and monitored, as were time to remission and any need for nitroglycerin administration. Results: Of 26 included patients, 19 (73%) were male, and the mean (SD) age was 65.5 (9.3) years. Patients underwent either PFA (n = 17) or RFA (n = 9) along the mitral isthmus. Coronary spasm was observed in 7 of 17 patients (41.2%) undergoing PFA: in 7 of 9 (77.8%) when the mitral isthmus ablation line was situated superiorly and in 0 of 8 when situated inferiorly. Conversely, coronary spasm did not occur in any of the 9 patients undergoing RFA. Of 5 patients in whom crossover PFA was performed after RFA failed to achieve conduction block, coronary spasm occurred in 3 (60%). Most instances of spasm (9 of 10 [90%]) were subclinical, with 2 (20%) requiring nitroglycerin administration. The median (range) time to resolution of spasm was 5 (5-25) minutes. Conclusion and Relevance: When creating a mitral isthmus ablation line during catheter ablation of atrial fibrillation, adjacent left circumflex arterial vasospasm frequently occurred with PFA and not RFA but was typically subclinical.

Nitroglycerin to Ameliorate Coronary Artery Spasm During Focal Pulsed-Field Ablation for Atrial Fibrillation.

BACKGROUND: In treating atrial fibrillation, pulsed-field ablation (PFA) has comparable efficacy to conventional thermal ablation, but with important safety advantages: no esophageal injury or pulmonary vein stenosis, and rare phrenic nerve injury. However, when PFA is delivered in proximity to coronary arteries using a pentaspline catheter, which generates a broad electrical field, severe vasospasm can be provoked. OBJECTIVES: The authors sought to study the vasospastic potential of a focal PFA catheter with a narrower electrical field and develop a preventive strategy with nitroglycerin. METHODS: During atrial fibrillation ablation, a focal PFA catheter was used for cavotricuspid isthmus ablation. Angiography of the right coronary artery (some with fractional flow reserve measurement) was performed before, during, and after PFA. Beyond no nitroglycerin (n = 5), and a few testing strategies (n = 8), 2 primary nitroglycerin administration strategies were studied: 1) multiple boluses (3-2 mg every 2 min) into the right atrium (n = 10), and 2) a bolus (3 mg) into the right atrium with continuous peripheral intravenous infusion (1 mg/min; n = 10). RESULTS: Without nitroglycerin, cavotricuspid isthmus ablation provoked moderate-severe vasospasm in 4 of 5 (80%) patients (fractional flow reserve 0.71 ± 0.08). With repetitive nitroglycerin boluses, severe spasm did not occur, and mild-moderate vasospasm occurred in only 2 of 10 (20%). Using the bolus + infusion strategy, severe and mild-moderate spasm occurred in 1 and 3 of 10 patients (aggregate 40%). No patient had ST-segment changes. CONCLUSIONS: Ablation of the cavotricuspid isthmus using a focal PFA catheter routinely provokes right coronary vasospasm. Pretreatment with high doses of parenteral nitroglycerin prevents severe spasm.

Severity of Ischemic Stroke After Left Atrial Appendage Closure vs Nonwarfarin Oral Anticoagulants.

BACKGROUND: Strokes after left atrial appendage closure (LAAC) prophylaxis are generally less severe than those after warfarin prophylaxis-thought to be secondary to more hemorrhagic strokes with warfarin. Hemorrhagic strokes are similarly infrequent with direct oral anticoagulant (DOAC) prophylaxis, so the primary subtype after either LAAC or DOAC prophylaxis is ischemic stroke (IS). OBJECTIVES: The purpose of this study was to compare the severity of IS using the modified Rankin Scale in atrial fibrillation patients receiving prophylaxis with DOACs vs LAAC. METHODS: A retrospective analysis was performed of consecutive patients undergoing LAAC at 8 centers who developed an IS (ISLAAC) compared with contemporaneous consecutive patients who developed IS during treatment with DOACs (ISDOAC). The primary outcome was disabling/fatal stroke (modified Rankin Scale 3-5) at discharge and 3 months later. RESULTS: Compared with ISDOAC patients (n = 322), ISLAAC patients (n = 125) were older (age 77.2 ± 13.4 years vs 73.1 ± 11.9 years; P = 0.002), with higher HAS-BLED scores (3.0 vs 2.0; P = 0.004) and more frequent prior bleeding events (54.4% vs 23.6%; P < 0.001), but similar CHA2DS2-VASc scores (5.0 vs 5.0; P = 0.28). Strokes were less frequently disabling/fatal with ISLAAC than ISDOAC at both hospital discharge (38.3% vs 70.3%; P < 0.001) and 3 months later (33.3% vs 56.2%; P < 0.001). Differences in stroke severity persisted after propensity score matching. By multivariate regression analysis, ISLAAC was independently associated with fewer disabling/fatal strokes at discharge (OR: 0.22; 95% CI: 0.13-0.39; P < 0.001) and 3 months (OR: 0.25; 95% CI: 0.12-0.50; P < 0.001), and fewer deaths at 3 months (OR: 0.28; 95% CI: 0.12-0.64; P < 0.001). CONCLUSIONS: Ischemic strokes in patients with atrial fibrillation are less often disabling or fatal with LAAC than DOAC prophylaxis.

Three-dimensional echocardiography in the evaluation of global and regional function in patients with recent myocardial infarction: a comparison with magnetic resonance imaging.

We aimed to compare three-dimensional (3D) and two-dimensional (2D) echocardiography in the evaluation of patients with recent myocardial infarction (MI), using late-enhancement magnetic resonance imaging (LE-MRI) as a reference method. Echocardiography and LE-MRI were performed approximately 1 month after first-time MI in 58 patients. Echocardiography was also performed on 35 healthy controls. Left ventricular (LV) ejection fraction by 3D echocardiography (3D-LVEF), 3D wall-motion score (WMS), 2D-WMS, 3D speckle tracking-based longitudinal, circumferential, transmural and area strain, and 2D speckle tracking-based longitudinal strain (LS) were measured. The global correlations to infarct size by LE-MRI were significantly higher (P < 0.03) for 3D-WMS and 2D-WMS compared with 3D-LVEF and the 4 different measurements of 3D strain, and 2D global longitudinal strain (GLS) was more closely correlated to LE-MRI than 3D GLS (P < 0.03). The segmental correlations to infarct size by LE-MRI were also significantly higher (P < 0.04) for 3D-WMS, 2D-WMS, and 2D LS compared with the other indices. Three-dimensional WMS showed a sensitivity of 76% and a specificity of 72% for identification of LV infarct size >12%, and a sensitivity of 73% and a specificity of 95% for identification of segments with transmural infarct extension. Three-dimensional WMS and 2D gray-scale echocardiography showed the strongest correlations to LE-MRI. The tested 3D strain method suffers from low temporal and spatial resolution in 3D acquisitions and added diagnostic value could not be proven.

Translational Rabbit Model of Chronic Cardiac Pacing.

Animal models of cardiac pacing are beneficial for testing novel devices, studying the pathophysiology of artificially paced heart rhythms, and studying arrhythmia-induced cardiomyopathies and subsequent heart failure. Currently, only a few such models are available, and they mostly require extensive resources. We report a new experimental cardiac pacing model in small mammals with the potential to study arrhythmia-induced heart failure. In six New Zealand white rabbits (mean weight: 3.5 kg) under general inhalational anesthesia the jugular region was dissected and a single pacing lead was inserted via the right external jugular vein. Using fluoroscopic guidance, the lead was further advanced to the right ventricular apex, where it was stabilized using passive fixation. A cardiac pacemaker was then connected and buried in a subcutaneous pocket. The pacemaker implantation was successful with good healing; the rabbit anatomy is favorable for the lead placement. During 6 months of follow-up with intermittent pacing, the mean sensed myocardial potential was 6.3 mV (min: 2.8 mV, max: 12 mV), and the mean lead impedance measured was 744 Ω (min: 370 Ω, max: 1014 Ω). The pacing threshold was initially 0.8 V ± 0.2 V and stayed stable during the follow-up. This present study is the first to present successful transvenous cardiac pacing in a small-mammal model. Despite the size and tissue fragility, human-size instrumentation with adjustments can safely be used for chronic cardiac pacing, and thus, this innovative model is suitable for studying the development of arrhythmia-induced cardiomyopathy and consequent heart failure pathophysiology.

Therapeutic Effect of Argatroban During Cardiopulmonary Resuscitation and Streptokinase During Extracorporeal Cardiopulmonary Resuscitation in a Porcine Model of Prolonged Cardiac Arrest.

Prolonged cardiac arrest (CA) causes microvascular thrombosis which is a potential barrier to organ reperfusion during extracorporeal cardiopulmonary resuscitation (ECPR). The aim of this study was to test the hypothesis that early intra-arrest anticoagulation during cardiopulmonary resuscitation (CPR) and thrombolytic therapy during ECPR improve recovery of brain and heart function in a porcine model of prolonged out-of-hospital CA. DESIGN: Randomized interventional trial. SETTING: University laboratory. SUBJECTS: Swine. INTERVENTIONS: In a blinded study, 48 swine were subjected to 8 minutes of ventricular fibrillation CA followed by 30 minutes of goal-directed CPR and 8 hours of ECPR. Animals were randomized into four groups (n = 12) and given either placebo (P) or argatroban (ARG; 350 mg/kg) at minute 12 of CA and either placebo (P) or streptokinase (STK, 1.5 MU) at the onset of ECPR. MEASUREMENTS AND MAIN RESULTS: Primary outcomes included recovery of cardiac function measured by cardiac resuscitability score (CRS: range 0-6) and recovery of brain function measured by the recovery of somatosensory-evoked potential (SSEP) cortical response amplitude. There were no significant differences in recovery of cardiac function as measured by CRS between groups (p = 0.16): P + P 2.3 (1.0); ARG + P = 3.4 (2.1); P + STK = 1.6 (2.0); ARG + STK = 2.9 (2.1). There were no significant differences in the maximum recovery of SSEP cortical response relative to baseline between groups (p = 0.73): P + P = 23% (13%); ARG + P = 20% (13%); P + STK = 25% (14%); ARG + STK = 26% (13%). Histologic analysis demonstrated reduced myocardial necrosis and neurodegeneration in the ARG + STK group relative to the P + P group. CONCLUSIONS: In this swine model of prolonged CA treated with ECPR, early intra-arrest anticoagulation during goal-directed CPR and thrombolytic therapy during ECPR did not improve initial recovery of heart and brain function but did reduce histologic evidence of ischemic injury. The impact of this therapeutic strategy on the long-term recovery of cardiovascular and neurological function requires further investigation.

Intracardiac Echocardiography-Guided Left Atrial Appendage Closure With a Novel Foam-Based Conformable Device: Safety and 1-Year Outcomes.

OBJECTIVES: This is a first report of the safety and 1-year outcomes of left atrial appendage closure (LAAC) using a novel foam-based conformable device, guided by intracardiac echocardiography (ICE). BACKGROUND: Limitations of current transcatheter LAAC devices include the need for precise coaxial delivery into the left atrial appendage (LAA), potential for traumatic implantation, incomplete LAA seal, and device-related thrombus. METHODS: The device (Conformal Left Atrial Appendage Seal, Conformal Medical Inc) is a self-expanding occluder consisting of a cylindrical nitinol endoskeleton with low-profile anchor barbs around the midpoint, covered with a porous foam cup. In a prospective single-center series, under conscious sedation, the device was delivered under fluoroscopic and ICE guidance. After positioning, a transesophageal echocardiography probe was placed to confirm ICE findings before device release. After closure, dual antiplatelet therapy was administered for 6 months. Follow-up imaging was planned for 45 days and 6 and 12 months. RESULTS: A total of 15 patients (age 71.3 ± 10.8 years, 33% men, CHA2DS2-VASc 4.1 ± 1.7, HAS-BLED 3.4 ± 1.4) underwent LAAC, 100% successfully. There were no procedure/device-related complications requiring intervention. Asymptomatic pericardial effusion occurred in 2 patients. The 45-day, 6-month, and 12-month follow-up imaging in 11, 9, and 13 patients, respectively, revealed adequate LAA seal (leak ≤5 mm) in all patients; device-related thrombus was detected in 1 patient at 6 months. Over 1-year follow-up, there were no ischemic strokes and 1 minor bleed. Nonprocedure-/device-related death occurred in 2 patients. CONCLUSIONS: This first report indicates that LAAC with the conformable implant guided by ICE imaging is feasible with encouraging 1-year clinical outcomes. (The Conformal Prague Study; NCT04193826).

4-Year Outcomes After Left Atrial Appendage Closure Versus Nonwarfarin Oral Anticoagulation for Atrial Fibrillation.

BACKGROUND: The PRAGUE-17 (Left Atrial Appendage Closure vs Novel Anticoagulation Agents in Atrial Fibrillation) trial demonstrated that left atrial appendage closure (LAAC) was noninferior to nonwarfarin direct oral anticoagulants (DOACs) for preventing major neurological, cardiovascular, or bleeding events in patients with atrial fibrillation (AF) who were at high risk. OBJECTIVES: This study sought to assess the prespecified long-term (4-year) outcomes in PRAGUE-17. METHODS: PRAGUE-17 was a randomized noninferiority trial comparing percutaneous LAAC (Watchman or Amulet) with DOACs (95% apixaban) in patients with nonvalvular AF and with a history of cardioembolism, clinically-relevant bleeding, or both CHA2DS2-VASc ≥3 and HASBLED ≥2. The primary endpoint was a composite of cardioembolic events (stroke, transient ischemic attack, or systemic embolism), cardiovascular death, clinically relevant bleeding, or procedure-/device-related complications (LAAC group only). The primary analysis was modified intention-to-treat. RESULTS: This study randomized 402 patients with AF (201 per group, age 73.3 ± 7.0 years, 65.7% male, CHA2DS2-VASc 4.7 ±1.5, HASBLED 3.1 ± 0.9). After 3.5 years median follow-up (1,354 patient-years), LAAC was noninferior to DOACs for the primary endpoint by modified intention-to-treat (subdistribution HR [sHR]: 0.81; 95% CI: 0.56-1.18; P = 0.27; P for noninferiority = 0.006). For the components of the composite endpoint, the corresponding sHRs were 0.68 (95% CI: 0.39-1.20; P = 0.19) for cardiovascular death, 1.14 (95% CI: 0.56-2.30; P = 0.72) for all-stroke/transient ischemic attack, 0.75 (95% CI: 0.44-1.27; P = 0.28) for clinically relevant bleeding, and 0.55 (95% CI: 0.31-0.97; P = 0.039) for nonprocedural clinically relevant bleeding. The primary endpoint outcomes were similar in the per-protocol (sHR: 0.80; 95% CI: 0.54-1.18; P = 0.25) and on-treatment (sHR: 0.82; 95% CI: 0.56-1.20; P = 0.30) analyses. CONCLUSIONS: In long-term follow-up of PRAGUE-17, LAAC remains noninferior to DOACs for preventing major cardiovascular, neurological, or bleeding events. Furthermore, nonprocedural bleeding was significantly reduced with LAAC. (PRAGUE-17 [Left Atrial Appendage Closure vs Novel Anticoagulation Agents in Atrial Fibrillation]; NCT02426944).

Retrieval of Long-Term Implanted Leadless Pacemakers: A Single-Center Experience.

OBJECTIVES: The authors report their single-center experience with the retrieval and replacement of long-term implanted leadless cardiac pacemakers (LPs) and the factors contributing to success. BACKGROUND: LPs are a clinically effective and safe alternative to standard transvenous pacemakers for single-chamber ventricular pacing. However, the feasibility of retrieving and replacing long-term implanted LPs is not well known. METHODS: A total of 34 patients with implanted Nanostim LPs (mean implantation duration 1,570 ± 479 days) subsequently underwent retrieval. On the basis of fluoroscopic imaging, the cohort was divided into 2 groups: those with remarkable swinging movement (SM) of the LP docking button (n = 25) and those without SM (n = 9). RESULTS: The overall LP retrieval success rate was 85% (n = 29). New leadless devices were implanted in 27 patients immediately after LP retrieval. No procedure-related adverse events occurred. The rate of successful LP retrieval was significantly higher in the SM group (25 of 25 [100%]) than in the no-SM group (4 of 9 [44%]) (p < 0.001), and fluoroscopy time during the retrieval procedure was shorter in the SM group (12.7 ± 8.6 min) than in the no-SM group (45.6 ± 19 min) (p < 0.001). CONCLUSIONS: This study demonstrated the feasibility and safety of retrieval of long-term implanted LPs after a mean duration of 4 years. Retrieval was most successful in patients whose docking buttons exhibited significant SM.