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ABSTRACT: OBJECTIVES: To assess the safety and efficacy of left atrial appendage closure (LAA) in non-valvular atrial fibrillation (AF) patients ineligible for warfarin therapy. BACKGROUND: The PROTECT AF trial demonstrated that LAA closure with the Watchman device was non-inferior to warfarin therapy. However, PROTECT AF only included patients that were candidates for warfarin, and even patients randomized to the LAA closure arm received concomitant warfarin for 6 weeks after Watchman implantation. METHODS: Multi-center, prospective, non-randomized study of LAA closure with the Watchman device in 150 patients with non-valvular AF and CHADS2 ≥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 and CHA2DS2-VASc scores 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 (13/150 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.
Journal of the American College of Cardiology 04/2013; · 14.16 Impact Factor
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Srinivas R Dukkipati,
Karl-Heinz Kuck,
Petr Neuzil,
Ian Woollett,
Josef Kautzner,
H Thomas McElderry,
Boris Schmidt,
Edward P Gerstenfeld,
Shephal K Doshi,
Rodney Horton,
Andreas Metzner,
Andre d'Avila,
Jeremy N Ruskin,
Andrea Natale, Vivek Y Reddy
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ABSTRACT: BACKGROUND: -Because of the technical difficulty with achieving pulmonary vein (PV) isolation in the treatment of patients with paroxysmal atrial fibrillation (PAF), novel catheter designs to facilitate the procedure are in development. A visually-guided laser ablation (VGLA) catheter was designed to allow the operator to directly visualize target tissue for ablation, and then deliver laser energy to perform point-to-point circumferential ablation. Single center studies have demonstrated favorable safety and efficacy. We sought to determine the multicenter feasibility, efficacy, and safety of performing PV isolation using the VGLA catheter. METHODS AND RESULTS: -This study includes the first 200 PAF patients treated with the VGLA catheter (33 operators, 15 centers). After transseptal puncture, the VGLA catheter was used to perform PV isolation. Electrical isolation was assessed using a circular mapping catheter. Using the VGLA catheter, 98.8% (95% CI, 97.8-99.5%) of targeted PVs were isolated using a mean of 1.07 catheters/patient. Fluoroscopy and procedure times were 31±21 (mean±sd) and 200±54 min respectively, and improved with operator experience. There were no instances of stroke, TIA, atrio-esophageal fistulas or significant PV stenosis. There was a 2% incidence of cardiac tamponade and 2.5% incidence of phrenic nerve palsy. At 12 months, the drug-free rate of freedom from atrial arrhythmias after one or two procedure was 60.2% (95% CI, 52.7-67.4%) CONCLUSIONS: -In this multicenter experience of the first 200 patients treated with the VGLA catheter, PV isolation can be achieved in virtually all patients using a single VGLA catheter with an efficacy similar to radiofrequency ablation.
Circulation Arrhythmia and Electrophysiology 04/2013; · 6.46 Impact Factor
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ABSTRACT: BACKGROUND: -Pulmonary vein (PV) isolation is the most prevalent approach for catheter ablation of paroxysmal atrial fibrillation (PAF). Long-term success of the procedure is diminished by arrhythmia recurrences occurring predominantly due to reconnections in previously isolated PVs. The aim of the EFFICAS I multicenter study was to demonstrate the correlation between contact force (CF) parameters during initial procedure and the incidence of isolation gaps ('gap') at 3 month follow-up (FU). Method and Results-A radiofrequency ablation catheter with integrated contact force sensor (TactiCath®, Endosense, Geneva, Switzerland) was used to perform PV isolation in 46 patients with PAF. During the ablation procedure, the operator was blinded to CF information. At FU, an interventional diagnostic procedure was performed to assess gap location as correlated to index procedure ablation parameters. At FU, 65% (26/40) of patients showed one or more gaps. Ablations with Minimum Force-Time integral (FTI) < 400 g.s showed increased likelihood for reconnection (p<0.001). Reconnection correlated strongly with Minimum CF (p<0.0001) and Minimum FTI (p=0.0007) at the site of gap. Gap occurrence showed a strong trend with lower average CF and average FTI. CF and FTI are generally higher on the right side, although the left anterior segment presents a unique challenge to achieve stable position with good CF. CONCLUSIONS: -Minimum CF and Minimum FTI values are strong predictors of gap formation. Optimal contact force parameter recommendations are a target CF of 20 g and a minimum FTI of 400 g.s for each new lesion.
Circulation Arrhythmia and Electrophysiology 03/2013; · 6.46 Impact Factor
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Heart rhythm: the official journal of the Heart Rhythm Society 02/2013; · 4.56 Impact Factor
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ABSTRACT: AIMS: The aim of the study was to assess the impact of isthmus location of atypical atrial flutters/atrial tachycardias (ATs) on outcomes of catheter ablation. Atrial tachycardias are clinically challenging arrhythmias that can occur in the presence of atrial scar-often due to either cardiac surgery or prior ablation for atrial fibrillation. We previously demonstrated a catheter ablation approach employing rapid multielectrode activation mapping with targeted entrainment manoeuvrs. However, the role that AT isthmus location plays in acute and long-term success of ablation remains uncertain.METHODS AND RESULTS: Retrospective multicenter analysis of 91 consecutive AT patients undergoing ablation using a systematic four-step approach: (i) high-density activation mapping; (ii) analysis of atrial activation to identify wavefronts of electrical propagation; (iii) targeted entrainment of putative channels; and (iv) irrigated radiofrequency ablation of constrained regions of the circuit. Clinical outcomes, procedural details, and clinical profiles were determined. A total of 171 ATs (1.9 ± 1.0 per patient, 26% septal ATs) were targeted for ablation. The acute success rates were 97 and 77% for patients with either non-septal ATs or septal ATs, respectively (P = 0.0023). Similarly, the long-term success rates were 82 and 67% for patients with either no septal ATs or at least one septal AT, respectively (P = 0.1057). The long-term success rates were 75, 88, and 57% for patients with ATs associated with prior catheter ablation, cardiac surgery or MAZE, and idiopathic atrial scar, respectively.CONCLUSION: Catheter ablation of AT can be successfully performed employing a strategy of combined high-density activation and entrainment mapping. Septal ATs are associated with higher rates of acute and long-term recurrences.
Europace 02/2013; · 1.98 Impact Factor
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ABSTRACT: BACKGROUND: The multicenter PROTECT AF study was conducted to determine whether percutaneous left atrial appendage (LAA) closure with a filter device (Watchman) was noninferior to warfarin for stroke prevention in atrial fibrillation (AF). METHODS AND RESULTS: Patients (n = 707) with nonvalvular AF and at least one risk factor (age > 75, hypertension, heart failure, diabetes or prior stroke/TIA) 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 endpoint included stroke, systemic embolism and cardiovascular death, and the primary analysis was by intention-to-treat. After 1,588 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 (RR = 0.71, 95% CI 0.44-1.30%/y), meeting the criteria for non-inferiority (probability of non-inferiority > 0.999). There were more primary safety events in the Watchman group (5.5%/y, 95% CI 4.2-7.1%/y) than in the control group (3.6%/y; 95% CI 2.2-5.3%/y; RR 1.53, 95% CI 0.95-2.70). CONCLUSIONS: The "local" strategy of LAA closure is noninferior to "systemic" anticoagulation with Warfarin. PROTECT AF has, for the first time, implicated the LAA in the pathogenesis of stroke in AF. CLINICAL TRIAL REGISTRATION INFORMATION: Clinicaltrials.gov; Unique Identifier: NCT00129545.
Circulation 01/2013; · 14.74 Impact Factor
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Humera Ahmed,
Marc A Miller,
Srinivas R Dukkipati,
Sam Cammack,
Jacob S Koruth,
Sandeep Gangireddy,
Betsy A Ellsworth,
Andre D'Avila,
Michael Domanski,
Annetine C Gelijns,
Alan Moskowitz, Vivek Y Reddy
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ABSTRACT: BACKGROUND: Hypertension is the most important risk factor directly attributable to the high prevalence of atrial fibrillation (AF), and is one of the few modifiable risk factors for AF. Activation and overactivity of the sympathetic nervous system (SNS) have been implicated in the pathogenesis of both essential hypertension and AF. Catheter-based renal sympathetic denervation (RSDN) appears to be an effective adjunctive treatment for refractory hypertension, and may be beneficial in other conditions characterized by SNS overactivity, such as left ventricular hypertrophy and atrial arrhythmias. OBJECTIVE: The H-FIB study is a multicenter prospective, double-blind, randomized (1:1) controlled trial. The primary efficacy endpoint is antiarrhythmic drug-free freedom from AF recurrence through 12 months. METHODS: Patients with a history of significant hypertension who are receiving treatment with at least one antihypertensive agent who are planned for a first time ablation for symptomatic paroxysmal or persistent AF will be randomized to either AF ablation alone (control group) or AF ablation + RSDN (study group). CONCLUSIONS: H-FIB is a multicenter, randomized trial that will test the hypothesis that adjunctive renal sympathetic denervation, at the time of AF ablation, will increase the freedom from recurrent AF.
Journal of Cardiovascular Electrophysiology 01/2013; · 3.06 Impact Factor
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ABSTRACT: BACKGROUND: -Percutaneous left ventricular assist devices (pLVADs) are increasingly being utilized to facilitate ablation of unstable ventricular tachycardia (VT), but the safety profile and hemodynamic benefits of these devices have not been described in a systematic, prospective manner. METHODS AND RESULTS: -Twenty patients with scar-VT underwent ablation with a pLVAD. Neuromonitoring utilizing cerebral oximetry was performed to evaluate a cerebral desaturation threshold to guide the duration of activation/entrainment mapping. The efficacy of pLVAD support was tested in a controlled manner with simulated VT. Complete procedural success was achieved in 50% (n=8) of patients who were initially inducible for sustained VT, and partial procedural success in 37% (n=6). Using a cerebral desaturation level of 55% as a lower safety limit to guide the duration of sustained VT, 3 patients (15%) developed mild acute kidney injury (all resolved), and 1 (5%) patient developed mild cognitive dysfunction. During fast simulated VT (300 ms), cerebral desaturation to ≤ 55% occurred in over half (53%) of patients tested without pLVAD support, compared to only 5% with full pLVAD support (p=0.003). CONCLUSIONS: -In a consecutive series of patients with severe left ventricular dysfunction, pLVAD-supported scar-VT ablation was safe and feasible. During fast simulated VT, a miniaturized axial flow pump imparted a more favorable hemodynamic profile compared to pharmacological agents alone. Cerebral oximetry is a complimentary monitoring modality during scar-VT ablation, and avoidance of cerebral desaturations below a threshold of 55% may safely guide the duration of mapping during unstable VT. Clinical Trials Registration Information-www.clinicaltrials.gov; Identifier: NCT01294267.
Circulation Arrhythmia and Electrophysiology 12/2012; · 6.46 Impact Factor
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ABSTRACT: AIMS: Although complex fractionated atrial electrograms (CFAEs) are purported to represent critical sites for atrial fibrillation (AF) perpetuation, the mechanism and the significance of CFAE in the genesis of AF remain poorly understood. This study evaluated the relationship between CFAE and areas of abnormal atrial tissue defined by low-voltage electrograms (LVE) and signal average of the P-wave (SAPW).METHODS AND RESULTS: Complex fractionated atrial electrogram maps were obtained after pulmonary vein isolation in 15 patients with persistent AF. Patients were then cardioverted and voltage/activation maps were acquired in normal sinus rhythm (NSR). Total left atrium (LA), CFAE and LVE areas were measured as % of total LA area (mean ± SD). Conduction velocities of normal, LVE and CFAE areas were also measured during NSR. Patients underwent signal averaged ECG of the P-wave in NSR within 24 h of the procedure. Complex fractionated atrial electrograms areas accounted for 33 ± 24% of total LA. In NSR, only 12 ± 10% of LA area had LVE. There was no anatomic correlation between CFAE sites and LVE; the area of overlap between CFAE and LVE was only 1.6 ± 1.5%. Conduction velocity was faster in CFAE areas (2.3 ± 1.4 m/s) than in normal voltage areas (1.3 ± 0.3 m/s), and LVE areas (1.1 ± 0.7 m/s, P = 0.06). A positive correlation was only found between LVE areas and SAPW duration (r = 0.7, P = 0.04).CONCLUSION: Areas of CFAEs correspond to areas of normal atrial voltage and normal conduction velocity during NSR. Complex fractionated atrial electrogram probably represents the response of normal healthy atrial tissue to rapid pulmonary vein activation.
Europace 11/2012; · 1.98 Impact Factor
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Petr Ostadal,
Mikulas Mlcek,
Frantisek Holy,
Svatava Horakova,
Stepan Kralovec,
Jan Skoda,
Jan Petru,
Andreas Kruger,
Vladimir Hrachovina,
Tomas Svoboda,
Otomar Kittnar, Vivek Y Reddy,
Petr Neuzil
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ABSTRACT: BACKGROUND: -Several percutaneous circulatory support systems have been recently introduced into clinical practice for the treatment of cardiogenic shock or refractory non-tolerated ventricular tachycardia, in support of high-risk catheter interventions and occasionally, cardiopulmonary resuscitation. To date, however, a direct comparison of the available systems has not been performed. METHODS AND RESULTS: -Adult female pigs (weight 50 kg to 60 kg) were used throughout the experiment. Under deep anesthesia and mechanical ventilation, three percutaneous circulatory support systems were compared: (i) right atrium - aorta (RA-Ao), extracorporeal membrane oxygenation (N=4); (ii) left atrium - aorta (LA-Ao), TandemHeart system (N=4); (iii) left ventricle - aorta (LV-Ao), Impella 2.5 system (N=4), and (iv) LV-Ao + norepinephrine (NE) 0.1 μg/kg/min (N=4). Hemodynamic efficacy (mean arterial pressure [MAP]) was measured at three specific conditions: ventricular pacing (VP) 200 beats/min and 300 beats/min, and ventricular fibrillation. While no or only non-significant differences were found among the systems at VP 200 beats/min and VP 300 beats/min, under ventricular fibrillation, the RA-Ao system was significantly the most efficacious, followed by the LA-Ao system, and the LV-Ao system (P<0.001). However, the LV-Ao system with NE still maintained MAP comparable with the LA-Ao system. CONCLUSIONS: -Differences were seen in the hemodynamic efficacy of available percutaneous circulatory support systems - particularly under the most severe hemodynamic condition, ventricular fibrillation.
Circulation Arrhythmia and Electrophysiology 10/2012; · 6.46 Impact Factor
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Journal of the American College of Cardiology 10/2012; 60(15):1433-4. · 14.16 Impact Factor
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ABSTRACT: AimsThe PROTECT-AF (WATCHMAN Left Atrial Appendage System for Embolic Protection in Patients with Atrial Fibrillation) trial found left atrial appendage (LAA) closure an alternative to anticoagulation in selected patients with non-valvular atrial fibrillation (AF). We aim to estimate the net clinical benefit (NCB) of percutaneous LAA closure.Methods and resultsPost hoc analysis of outcomes among 707 adults with AF in the PROTECT-AF trial and 566 in the Continued Access (CAP) registry undergoing LAA closure with the Watchman device compared with sustained anticoagulation. Outcomes were ischaemic stroke, intracranial haemorrhage, major bleeding, pericardial effusion, and death, weighted to reflect the relative impact in terms of death and disability. Net clinical benefit was calculated as the sum of annualized rates of these outcomes after intervention minus rates on warfarin. The NCB of LAA closure during 1623 person-years follow-up in the trial was 1.73%/year (95% CI: -0.54 to 4.39%/year) and during 741 patient-years in the registry was 4.97%/year (95% CI: 3.07-7.15%/year). Among patients with a history of ischaemic stroke, the NCB was greater in the registry (8.68%/year, CI: 2.82-14.92%/year) than the trial (4.30%/year, CI -2.07 to 11.25%/year). In the registry, the NCB of LAA closure increased from 2.22%/year (CI: 0.27-6.01%/year) in patients with CHADS(2) scores = 1 to 6.12%/year (CI: 3.19-8.92%/year) in those with scores ≥2.Conclusion
Combining rates of thrombo-embolism, intracranial haemorrhage, major adverse events, and death allows objective comparison of the benefit and risk of device therapy vs. anticoagulation in patients with AF. The NCB of LAA closure is greatest for patients at a higher risk of stroke.
European Heart Journal 09/2012; · 10.48 Impact Factor
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ABSTRACT: Atrial fibrillation is associated with increased mortality and considerable morbidity, including stroke, heart failure, and diminished quality of life. Despite these adverse outcomes, rhythm control has not demonstrated benefit in clinical trials. Antiarrhythmic medications, including recently developed agents, have limited efficacy in achieving durable sinus rhythm and substantial toxicity. A rate-control strategy is therefore more attractive for minimally symptomatic patients, but younger and more symptomatic patients may benefit from restoration of sinus rhythm. Catheter ablation is more effective than medications in preventing arrhythmia recurrence, avoids adverse effects associated with antiarrhythmic drugs, and should be considered early in symptomatic patients when success is likely. However, more definitive data are needed from randomized trials assessing long-term outcomes after ablation, including stroke risk and mortality. Clinical decision tools help select the appropriate management for individual patients. Lenient rate management is easy to achieve and seems reasonably safe for certain patients, although the optimum rate varies with individual comorbidities. Because safer and more effective pharmacologic and interventional therapies are now available, an individualized approach to atrial fibrillation management is essential.
The American journal of medicine 08/2012; 125(11):1049-56. · 4.47 Impact Factor
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ABSTRACT: Since the introduction of percutaneous epicardial access for the purpose of mapping and ablation of cardiac arrhythmias, this technique has become an important adjunct and at times the preferred approach to treat certain cardiac arrhythmias. In addition, this approach is currently also being considered for a number of other cardiovascular applications such as epicardial pacing, left atrial appendage ligature occlusion, etc. The focus of this review is to discuss relevant aspects of pericardial anatomy, and various methods of epicardial access.
Europace 08/2012; 14 Suppl 2:ii13-ii18. · 1.98 Impact Factor
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ABSTRACT: BACKGROUND: Irrigated radiofrequency (RF) ablation can be insufficient to eliminate intramurally located septal atrial flutter (AFL) and ventricular tachycardia (VT) circuits. Bipolar ablation between 2 ablation catheters may be considered for such circuits. OBJECTIVE: To evaluate the utility of bipolar irrigated ablation to terminate arrhythmias resistant to unipolar ablation. METHODS: In vitro: Bipolar and sequential unipolar RF ablation lesions were placed on porcine ventricular tissue in a saline bath to assess for lesion transmurality. Clinical: 3 patients with atypical septal flutter (AFL), 4 patients with septal VT, and 2 with left ventricle free-wall VT, all of whom failed sequential unipolar RF ablation, underwent bipolar RF ablation using irrigated catheters placed on either surface of the interatria/interventricular septum and left ventricle free-wall, respectively. RESULTS: In vitro: Bipolar RF was found to be more likely to achieve transmural lesions (82% vs 33%; P = .001) and could do so in tissues with thicknesses of up to 25 mm. Clinical: All 5 AFLs (3 patients) were successfully terminated with bipolar RF. In follow-up, AFL recurred in 2 of the 3 patients and atrial fibrillation and AFL recurred in 1 of the 3. All 3 thereafter underwent repeat procedures with successful maintenance of sinus rhythm in 2 of the 3 patients (6-month follow-up). In the VT subgroup, 5 of 6 septal VTs and 2 of 3 free-wall VTs were terminated successfully during ablation. In follow-up (12 months), 2 of the 4 patients in the septal bipolar group and 1 of the 2 patients in the free-wall group remained free of VT. CONCLUSIONS: Bipolar RF can be used to terminate arrhythmias in select patients with tachyarrhythmias.
Heart rhythm: the official journal of the Heart Rhythm Society 08/2012; · 4.56 Impact Factor
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Vivek Y Reddy,
Dipen Shah,
Josef Kautzner,
Boris Schmidt,
Nadir Saoudi,
Claudia Herrera,
Pierre Jaïs,
Gerhard Hindricks,
Petr Peichl,
Aude Yulzari,
Hendrik Lambert,
Petr Neuzil,
Andrea Natale,
Karl-Heinz Kuck
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ABSTRACT: BACKGROUND: The clinical efficacy of catheter ablation of paroxysmal atrial fibrillation (AF) remains limited by difficulty in achieving durable pulmonary vein isolation (PVI). Suboptimal catheter tip-to-tissue contact force (CF) during lesion delivery is believed to reduce clinical efficacy. OBJECTIVE: To determine the relationship between catheter CF during irrigated catheter ablation for AF and clinical recurrences during follow-up. METHODS: Thirty-two patients with paroxysmal AF underwent PVI by using a radiofrequency ablation catheter with a CF sensor integrated at its tip, and they were followed for 12 months. The relationship between the CF and clinical outcomes was determined. RESULTS: Acute PVI was achieved in 100% of the veins. Thirty-five percent (351 of 1017) of the applications were placed with an average CF of <10 g (low CF). All patients treated with an average CF of <10 g (5 of 5 patients) experienced recurrences, whereas 80% of the patients treated with an average CF of >20 g (8 of 10 patients) were free from AF recurrence at 12 months. The analysis of the average force-time integral showed that 75% of the patients treated with <500 gs were recurrent whereas only 31% of the patients treated with >1000 gs had recurrences at 12 months. CONCLUSIONS: The CF during catheter ablation for AF correlates with clinical outcome. Arrhythmia control is best achieved when ablation lesions are placed with an average CF of >20 g, and clinical failure is universally noted with an average CF of <10 g.
Heart rhythm: the official journal of the Heart Rhythm Society 07/2012; · 4.56 Impact Factor
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ABSTRACT: 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.
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.
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.
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).
These data provide the proof-of-principle that RSDN can be performed using an off-the-shelf saline-irrigated RFA catheter.
07/2012; 5(7):758-65. · 1.07 Impact Factor
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ABSTRACT: Temporary, ablation-mediated effects such as oedema may cause reversible pulmonary vein (PV) isolation. To investigate this, point-by-point circumferential ablation was performed to achieve acute electrical PV isolation with an incomplete circumferential ablation line. Then, the impact of this intentional 'visual gap' (ViG) on the conduction properties of the ablation lesion set was assessed with adenosine and pacing manoeuvres.
Twenty-eight patients undergoing ablation for paroxysmal (n= 20) or persistent atrial fibrillation (n= 8) were included. Pulmonary vein (PV) ablation was performed around ipsilateral vein pairs. Once acute isolation was achieved, ablation was halted and the presence and size of the ViG were calculated. The ViG electrophysiological properties were tested with pace capture along the ViG at 10 mA/2 ms, and assessment for dormant PV conduction with adenosine. Despite electrical isolation, a ViG was present in 75% (n= 42/56) of vein pairs (21 of 28 left PVs and 21 of 28 right PVs). There was no difference in the ViG size between the left and right PVs (22.1 ± 14.2 and 17.3 ± 11.3 mm, P > 0.05). Dormant PV connections were revealed by adenosine in more than a quarter (n= 12/42) of acutely isolated PV pairs, of which the majority were dependent on conduction through the ViG.
Electrical PV isolation can usually be achieved without complete circumferential ablation. However, more than a quarter of these 'isolated' PVs exhibit dormant conduction-predominantly via the un-ablated 'ViGs' in the ablation lesion set. These findings support the hypothesis that reversible tissue injury contributes to PV isolation that may be acute but not necessarily durable.
Europace 03/2012; 14(5):653-60. · 1.98 Impact Factor
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ABSTRACT: The purpose of this study was to investigate the frequency and clinical impact of incomplete left atrial appendage (LAA) sealing and consequent peri-device residual blood flow in patients undergoing percutaneous LAA closure with the Watchman device (Atritech, Inc., Plymouth, Minnesota).
During percutaneous LAA closure for stroke prophylaxis, the geometric variability of the LAA ostium may result in an incomplete seal of the LAA. On the one hand, this could enhance thrombus formation and embolization of thrombi around the device into the circulation; on the other hand, the relatively small size of these leaks may preclude clinically relevant embolizations.
Patients randomly assigned to device implantation in the PROTECT AF (Percutaneous Closure of the Left Atrial Appendage Versus Warfarin Therapy for Prevention of Stroke in Patients With Atrial Fibrillation) trial were analyzed. Transesophageal echocardiography was performed at 45 days, 6 months, and 12 months. Per the study protocol, patients discontinued warfarin therapy if the 45-day Transesophageal echocardiogram revealed either minimal or no peri-device flow (jet ≤5 mm width). The impact of peri-device flow severity, defined as minor, moderate, or major (<1 mm, 1 mm to 3 mm, >3 mm, respectively) on the composite primary efficacy endpoint (stroke, systemic embolism, and cardiovascular death) is expressed as hazard ratio (HR) with 95% confidence interval (CI).
Transesophageal echocardiography follow-up revealed that 32.0% of implanted patients had at least some degree of peri-device flow at 12 months. The HR of the primary efficacy endpoint per 1 mm larger per-device flow was 0.84 (95% CI: 0.62 to 1.14; p = 0.256). Compared to patients with no peri-device flow, the HRs were 0.85 (95% CI: 0.11 to 6.40), 0.83 (95% CI: 0.33 to 2.09), and 0.48 (95% CI: 0.11 to 2.09) for minor, moderate, and major peri-device flow, respectively (p = 0.798). Compared to patients with no peri-device flow who discontinued warfarin, the HR for patients with any peri-device flow and continuing warfarin was 0.63 (95% CI: 0.14 to 2.71; p = 0.530).
These data indicate that residual peri-device flow into the LAA after percutaneous closure with the Watchman device was common, and is not associated with an increased risk of thromboembolism. This finding should be interpreted with caution as the low event rate decreases the confidence of this conclusion.
Journal of the American College of Cardiology 03/2012; 59(10):923-9. · 14.16 Impact Factor
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Heart rhythm: the official journal of the Heart Rhythm Society 02/2012; 9(7):1168-76. · 4.56 Impact Factor
