Homolka Hospital

Prague, Czech Republic

Homolka Hospital

Prague, Czech Republic
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Reddy V.Y.,Mount Sinai School of Medicine | Reddy V.Y.,Homolka Hospital | Reddy V.Y.,St Johns Health Center | Holmes D.,Mayo Medical School | And 3 more authors.
Circulation | Year: 2011

Background- The Watchman Left Atrial Appendage System for Embolic Protection in Patients With AF (PROTECT AF) randomized trial compared left atrial appendage closure against warfarin in atrial fibrillation (AF) patients with CHADS2 1. Although the study met the primary efficacy end point of being noninferior to warfarin therapy for the prevention of stroke/systemic embolism/cardiovascular death, there was a significantly higher risk of complications, predominantly pericardial effusion and procedural stroke related to air embolism. Here, we report the influence of experience on the safety of percutaneous left atrial appendage closure. Methods and Results- The study cohort for this analysis included patients in the PROTECT AF trial who underwent attempted device left atrial appendage closure (n=542 patients) and those from a subsequent nonrandomized registry of patients undergoing Watchman implantation (Continued Access Protocol [CAP] Registry; n=460 patients). The safety end point included bleeding- and procedure-related events (pericardial effusion, stroke, device embolization). There was a significant decline in the rate of procedure- or device-related safety events within 7 days of the procedure across the 2 studies, with 7.7% and 3.7% of patients, respectively, experiencing events (P=0.007), and between the first and second halves of PROTECT AF and CAP, with 10.0%, 5.5%, and 3.7% of patients, respectively, experiencing events (P=0.006). The rate of serious pericardial effusion within 7 days of implantation, which had made up >50% of the safety events in PROTECT AF, was lower in the CAP Registry (5.0% versus 2.2%, respectively; P=0.019). There was a similar experience-related improvement in procedure-related stroke (0.9% versus 0%, respectively; P=0.039). Finally, the functional impact of these safety events, as defined by significant disability or death, was statistically superior in the Watchman group compared with the warfarin group in PROTECT AF. This remained true whether significance was defined as a change in the modified Rankin score of 1, 2, or 3 (1.8 versus 4.3 events per 100 patient-years; relative risk, 0.43; 95% confidence interval, 0.24 to 0.82; 1.5 versus 3.7 events per 100 patient-years; relative risk, 0.41; 95% confidence interval, 0.22 to 0.82; and 1.4 versus 3.3 events per 100 patient-years; relative risk, 0.43; 95% confidence interval, 0.22 to 0.88, respectively). Conclusion- As with all interventional procedures, there is a significant improvement in the safety of Watchman left atrial appendage closure with increased operator experience. CLINICAL TRIAL REGISTRATION-: URL: http://clinicaltrials.gov. Unique identifier: NCT00129545. Copyright © 2011 American Heart Association. All rights reserved.


Reddy V.Y.,Mount Sinai School of Medicine | Knops R.E.,University of Amsterdam | Sperzel J.,Kerckhoff Heart and Thorax Center | Miller M.A.,Mount Sinai School of Medicine | And 12 more authors.
Circulation | Year: 2014

Background-: Conventional cardiac pacemakers are associated with several potential short-and long-term complications related to either the transvenous lead or subcutaneous pulse generator. We tested the safety and clinical performance of a novel, completely self-contained leadless cardiac pacemaker. Methods and Results-: The primary safety end point was freedom from complications at 90 days. Secondary performance end points included implant success rate, implant time, and measures of device performance (pacing/sensing thresholds and rate-responsive performance). The mean age of the patient cohort (n=33) was 77±8 years, and 67% of the patients were male (n=22/33). The most common indication for cardiac pacing was permanent atrial fibrillation with atrioventricular block (n=22, 67%). The implant success rate was 97% (n=32). Five patients (15%) required the use of >1 leadless cardiac pacemaker during the procedure. One patient developed right ventricular perforation and cardiac tamponade during the implant procedure, and eventually died as the result of a stroke. The overall complication-free rate was 94% (31/33). After 3 months of follow-up, the measures of pacing performance (sensing, impedance, and pacing threshold) either improved or were stable within the accepted range. Conclusions-: In a prospective nonrandomized study, a completely self-contained, single-chamber leadless cardiac pacemaker has shown to be safe and feasible. The absence of a transvenous lead and subcutaneous pulse generator could represent a paradigm shift in cardiac pacing. Clinical Trial Registration-: URL: http://clinicaltrials.gov. Unique identifier: NCT01700244. © 2014 American Heart Association, Inc.


Knops R.E.,University of Amsterdam | Tjong F.V.Y.,University of Amsterdam | Neuzil P.,Homolka Hospital | Sperzel J.,Kerckhoff Heart and Thorax Center | And 10 more authors.
Journal of the American College of Cardiology | Year: 2015

Background A leadless cardiac pacemaker (LCP) system was recently introduced to overcome lead-related complications of conventional pacing systems. To date, long-term results of an LCP system are unknown. Objectives The aim of this study was to assess the complication incidence, electrical performance, and rate response characteristics within the first year of follow-up of patients implanted with an LCP. Methods We retrospectively assessed intermediate-term follow-up data for 31 of 33 patients from the LEADLESS trial cohort who had an indication for single-chamber pacing and received an LCP between December 2012 and April 2013. Results The mean age of the cohort was 76 ± 8 years, and 65% were male. Between 3 and 12 months of follow-up, there were no pacemaker-related adverse events reported. The pacing performance results at 6- and 12-month follow-up were, respectively, as follows: mean pacing threshold (at a 0.4-ms pulse width), 0.40 ± 0.26 V and 0.43 ± 0.30 V; R-wave amplitude 10.6 ± 2.6 mV and 10.3 ± 2.2 mV; and impedance 625 ± 205 Ω and 627 ± 209 Ω. At the 12-month follow-up in 61% of the patients (n = 19 of 31), the rate response sensor was activated, and an adequate rate response was observed in all patients. Conclusions The LCP demonstrates very stable performance and reassuring safety results during intermediate-term follow-up. These results support the use of the LCP as a promising alternative to conventional pacemaker systems. Continued evaluation is warranted to further characterize this system. (Evaluation of a New Cardiac Pacemaker; NCT01700244) © 2015 American College of Cardiology Foundation.


Reddy V.Y.,Mount Sinai School of Medicine | Reddy V.Y.,St Johns Health Center | Reddy V.Y.,Homolka Hospital | Doshi S.K.,St Johns Health Center | And 6 more authors.
Circulation | Year: 2013

Background-The multicenter PROTECT AF study (Watchman Left Atrial Appendage System for Embolic Protection in Patients With Atrial Fibrillation) was conducted to determine whether percutaneous left atrial appendage closure with a filter device (Watchman) was noninferior to warfarin for stroke prevention in atrial fibrillation. Methods and Results-Patients (n=707) with nonvalvular atrial fibrillation and at least 1 risk factor (age >75 years, hypertension, heart failure, diabetes, or prior stroke/transient ischemic attack) were randomized to either the Watchman device (n=463) or continued warfarin (n=244) in a 2:1 ratio. After device implantation, warfarin was continued for ≈45 days, followed by clopidogrel for 4.5 months and lifelong aspirin. Study discontinuation rates were 15.3% (71/463) and 22.5% (55/244) for the Watchman and warfarin groups, respectively. The time in therapeutic range for the warfarin group was 66%. The composite primary efficacy end point included stroke, systemic embolism, and cardiovascular death, and the primary analysis was by intention to treat. After 1588 patient-years of follow-up (mean 2.3±1.1 years), the primary efficacy event rates were 3.0% and 4.3% (percent per 100 patient-years) in the Watchman and warfarin groups, respectively (relative risk, 0.71; 95% confidence interval, 0.44%-1.30% per year), which met the criteria for noninferiority (probability of noninferiority >0.999). There were more primary safety events in the Watchman group (5.5% per year; 95% confidence interval, 4.2%-7.1% per year) than in the control group (3.6% per year; 95% confidence interval, 2.2%-5.3% per year; relative risk, 1.53; 95% confidence interval, 0.95-2.70). Conclusions-The "local" strategy of left atrial appendage closure is noninferior to "systemic" anticoagulation with warfarin. PROTECT AF has, for the first time, implicated the left atrial appendage in the pathogenesis of stroke in atrial fibrillation. Clinical Trial Registration:-URL: http://www.clinicaltrials.gov. Unique identifier: NCT00129545. (Circulation. 2013;127:720-729.). © 2013 American Heart Association, Inc.


Reddy V.Y.,Mount Sinai School of Medicine | Dukkipati S.R.,Mount Sinai School of Medicine | Neuzil P.,Homolka Hospital | Natale A.,The Texas Institute | And 9 more authors.
Circulation | Year: 2015

Background-Contact force (CF) is a major determinant of lesion size and transmurality and has the potential to improve efficacy of atrial fibrillation ablation. This study sought to evaluate the safety and effectiveness of a novel irrigated radiofrequency ablation catheter that measures real-time CF in the treatment of patients with paroxysmal atrial fibrillation. Methods and Results-A total of 300 patients with symptomatic, drug-refractory, paroxysmal atrial fibrillation were enrolled in a prospective, multicenter, randomized, controlled trial and randomized to radiofrequency ablation with either a novel CF-sensing catheter or a non-CF catheter (control). The primary effectiveness end point consisted of acute electrical isolation of all pulmonary veins and freedom from recurrent symptomatic atrial arrhythmia off all antiarrhythmic drugs at 12 months. The primary safety end point included device-related serious adverse events. End points were powered to show noninferiority. All pulmonary veins were isolated in both groups. Effectiveness was achieved in 67.8% and 69.4% of subjects in the CF and control arms, respectively (absolute difference,-1.6%; lower limit of 1-sided 95% confidence interval,-10.7%; P=0.0073 for noninferiority). When the CF arm was stratified into optimal CF (≥90% ablations with ≥10 g) and nonoptimal CF groups, effectiveness was achieved in 75.9% versus 58.1%, respectively (P=0.018). The primary safety end point occurred in 1.97% and 1.40% of CF patients and control subjects, respectively (absolute difference, 0.57%; upper limit of 1-sided 95% confidence interval, 3.61%; P=0.0004 for noninferiority). Conclusions-The CF ablation catheter met the primary safety and effectiveness end points. Additionally, optimal CF was associated with improved effectiveness. © 2015 American Heart Association, Inc.


Miller M.A.,Mount Sinai School of Medicine | Gangireddy S.R.,Mount Sinai School of Medicine | Doshi S.K.,Pacific Heart Institute | Aryana A.,Mercy Heart and Vascular Institute | And 6 more authors.
Heart rhythm : the official journal of the Heart Rhythm Society | Year: 2014

BACKGROUND: Pericardial suture ligation of the left atrial appendage (LAA) may be an alternative to endoluminal devices for stroke prevention in patients with atrial fibrillation, but multicenter safety and efficacy data in high-risk patients with contraindications to oral anticoagulation are lacking.OBJECTIVE: The purpose of this study was to report the outcomes of consecutive cases of pericardial suture ligation of the LAA in high-risk patients performed at 4 centers.METHODS: The cohort included 41 consecutive patients who underwent LAA closure with the LARIAT system. Epicardial and transeptal access was obtained, and the epicardial snare was advanced over an endo-epicardial magnetic-tipped guidewire to close the LAA. Transesophageal echocardiography was used to confirm LAA exclusion.RESULTS: Mean age was 75 ± 10 years, mean CHADS2 score was 3.0 ± 1.3, and mean HAS-BLED score was 4.4 ± 1.4. These patients accumulated 24.6 person-years of follow-up. Acute LAA closure was achieved in 38 patients (93%). Transesophageal echocardiography or computerized tomographic angiography performed up to 3.3 ± 0.8 months after the procedure demonstrated LAA leakage in 24% of patients. One patient (2%) had a transient ischemic attack, and 8 (20%) developed pericardial effusions requiring pericardiocentesis. Four cases (9%) were complicated by perforation of the LAA, with 2 of these patients requiring open surgical correction.CONCLUSION: This multicenter experience revealed that pericardial suture ligation with the LARIAT system is technically feasible and acutely efficacious. However, additional improvements are required to minimize the rate of pericardial complications. A randomized study is warranted to accurately define the long-term efficacy and safety profile of percutaneous epicardial suture ligation. Copyright © 2014. Published by Elsevier Inc.


Miller M.A.,Helmsley Electrophysiology Center | Neuzil P.,Homolka Hospital | Dukkipati S.R.,Helmsley Electrophysiology Center | Reddy V.Y.,Helmsley Electrophysiology Center
Journal of the American College of Cardiology | Year: 2015

Despite significant advances in battery longevity, lead performance, and programming features since the first implanted permanent pacemaker was developed, the basic design of cardiac pacemakers has remained relatively unchanged over the past 50 years. Because of inherent limitations in their design, conventional (transvenous) pacemakers are prone to multiple potential short- and long-term complications. Accordingly, there has been intense interest in a system able to provide the symptomatic and potentially lifesaving therapies of cardiac pacemakers while mitigating many of the risks associated with their weakest link - the transvenous lead. Leadless cardiac pacing represents the future of cardiac pacing systems, similar to the transition that occurred from the use of epicardial pacing systems to the familiar transvenous systems of today. This review summarizes the current evidence and potential benefits of leadless pacing systems, which are either commercially available (in Europe) or under clinical investigation. © 2015 American College of Cardiology Foundation.


Reddy V.Y.,Mount Sinai School of Medicine | Mobius-Winkler S.,University of Leipzig | Miller M.A.,Mount Sinai School of Medicine | Neuzil P.,Homolka Hospital | And 4 more authors.
Journal of the American College of Cardiology | Year: 2013

Objectives The purpose of this study was to assess the safety and efficacy of left atrial appendage (LAA) closure in nonvalvular atrial fibrillation (AF) patients ineligible for warfarin therapy. Background The PROTECT AF (Watchman Left Atrial Appendage System for Embolic Protection in Patients With Atrial Fibrillation) trial demonstrated that LAA closure with the Watchman device (Boston Scientific, Natick, Massachusetts) was noninferior to warfarin therapy. However, the PROTECT AF trial only included patients who were candidates for warfarin, and even patients randomly assigned to the LAA closure arm received concomitant warfarin for 6 weeks after Watchman implantation. Methods A multicenter, prospective, nonrandomized study was conducted of LAA closure with the Watchman device in 150 patients with nonvalvular AF and CHADS2 (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, and prior stroke or transient ischemic attack) score ≥1, who were considered ineligible for warfarin. The primary efficacy endpoint was the combined events of ischemic stroke, hemorrhagic stroke, systemic embolism, and cardiovascular/unexplained death. Results The mean CHADS2 score and CHA2DS2-VASc (CHADS2 score plus 2 points for age ≥75 years and 1 point for vascular disease, age 65 to 74 years, or female sex) score were 2.8 ± 1.2 and 4.4 ± 1.7, respectively. History of hemorrhagic/bleeding tendencies (93%) was the most common reason for warfarin ineligibility. Mean duration of follow-up was 14.4 ± 8.6 months. Serious procedure- or device-related safety events occurred in 8.7% of patients (13 of 150 patients). All-cause stroke or systemic embolism occurred in 4 patients (2.3% per year): ischemic stroke in 3 patients (1.7% per year) and hemorrhagic stroke in 1 patient (0.6% per year). This ischemic stroke rate was less than that expected (7.3% per year) based on the CHADS2 scores of the patient cohort. Conclusions LAA closure with the Watchman device can be safely performed without a warfarin transition, and is a reasonable alternative to consider for patients at high risk for stroke but with contraindications to systemic oral anticoagulation. (ASA Plavix Feasibility Study With Watchman Left Atrial Appendage Closure Technology [ASAP]; NCT00851578).© 2013 by the American College of Cardiology Foundation Published by Elsevier Inc.


Ahmed H.,Mount Sinai School of Medicine | Ahmed H.,Homolka Hospital | Neuzil P.,Homolka Hospital | Skoda J.,Homolka Hospital | And 5 more authors.
JACC: Cardiovascular Interventions | Year: 2012

Objectives: This study sought to assess whether renal sympathetic denervation (RSDN) can be achieved using an off-the-shelf saline-irrigated radiofrequency ablation (RFA) catheter typically employed for cardiac tissue ablation. Background: RSDN using a specialized solid-tip RFA catheter has recently been demonstrated to safely reduce systemic blood pressure in patients with refractory hypertension. For cardiac tissue ablation, RFA technology has evolved from nonirrigated to saline-irrigated ablation electrodes to improve both safety and effectiveness. Methods: Ten patients with resistant hypertension underwent renal angiography, followed by bilateral RSDN with a saline-irrigated RFA catheter. Ambulatory blood pressure recordings (24 h) were obtained at baseline, 1, 3, and 6 months after the procedure. Repeat renal angiography was performed during follow-up to assess for arterial stenosis or aneurysm. In 5 patients, pre- and post-procedural serum measures of renal function and sympathetic activity were obtained: aldosterone; metanephrine; normetanephrine; plasma renin activity; and creatinine. Results: Over a 6-month period: 1) the systolic/diastolic blood pressure decreased by -21/-11 mm Hg; 2) all patients experienced a decrease in systolic blood pressure of at least 10 mm Hg (range 10 to 40 mm Hg); 3) there was no evidence of renal artery stenosis or aneurysm at repeat angiography; and 4) there was a significant decrease in metanephrine (-12 ± 4, p = 0.003), normetanephrine (-18 ± 4, p = 0.0008), and aldosterone levels (-60 ± 33 ng/l, p = 0.02) at 3 months. There was no significant change in plasma renin activity (-0.2 mg/l/hod, p = 0.4). There was no significant change in serum creatinine (-1 mmol/l, p = 0.4). Conclusions: These data provide the proof-of-principle that RSDN can be performed using an off-the-shelf saline-irrigated RFA catheter. © 2012 by the American College of Cardiology Foundation.


Neuzil P.,Na Homolce Hospital | Reddy V.Y.,Homolka Hospital | Reddy V.Y.,Mount Sinai School of Medicine
Current Cardiology Reports | Year: 2015

Traditional transvenous approach for permanent cardiac pacing can be associated with significant acute and chronic complications related partly to either the insertion of transvenous lead or subcutaneous placement of pacemaker device. We summarize the current status of a novel self-contained leadless cardiac pacemaker in the first-in-human and subsequent series of feasibility studies in patients indicated for ventricular rate-responsive pacing (VVI). Using a femoral venous approach, the device is implanted at the right ventricular apical septum region. We describe the technical and clinical characterization of this innovative technology. Two different systems of leadless pacemakers are currently implanted to the patients. Up to now, the electrical parameters, such as pacing thresholds, sensing parameters, and pacing impedances, either improved or remained stable within the accepted range. In this chapter, we also discuss the potential benefit for the future, but in summary, all available data demonstrate the feasibility of leadless cardiac pacing. © 2015, Springer Science+Business Media New York.

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