[Show abstract][Hide abstract] ABSTRACT: Introduction:
More advanced Atrial Fibrillation (AF) is associated with lower success rates after pulmonary vein isolation (PVI) and the optimal ablation strategy is uncertain.
To assess the impact of additional linear ablation (lines) compared to PVI alone.
In this multi-center randomised controlled trial, 122 patients (age 61.9±10.5years, left atrial diameter 43±6mm), with persistent (PeAF) or sustained (>12h) paroxysmal (SusPAF) AF with risk factors for atrial substrate were included and followed-up for 12 months. Randomisation was to PVI only or PVI+lines (left atrial roof, mitral and tricuspid isthmi). Holter monitoring was performed at 3, 6 and 12 months and according to symptoms. The primary outcome was atrial tachyarrhythmia recurrence ≥30s.
Baseline characteristics were comparable between groups; 61% had PeAF and 39% SusPAF. Successful PVI was achieved for 98% of pulmonary veins and bidirectional block was obtained in 90% of lines. The primary endpoint occurred in 38% of the PVI+lines group and 32% of the PVI group (P=0.50), consistent both in PeAF (36% v 28%, P=0.45) and SusPAF (42% v 39%, P=0.86). Compared to the PVI only group, the PVI+lines group had higher procedure duration (209±52 v 172±44minutes, P<0.001), ablation time (4352±1084 v 2503±1061seconds, P<0.001), and radiation exposure (DAP 3992±6496 v 2106±1679Gy.cm(2), P=0.03). Quality of Life (disease-specific AFEQT and SF36 Mental Component) improved significantly during the study but did not differ between groups.
Adding lines to wide antral PVI in substrate-based AF requires significantly more ablation, increases procedure duration and radiation dose, but provides no additional clinical benefit.
Clinical trial registration:
Heart rhythm: the official journal of the Heart Rhythm Society 10/2015; DOI:10.1016/j.hrthm.2015.10.006 · 5.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Introduction: Recent evidence supports left atrial appendage closure (LAAC) as a cost-effective alternative to warfarin. However these findings, based on clinical trial populations, may not be generalisable to clinical practice. The cost-impact of a real world experience of LAAC compared with warfarin, dabigatran, rivaroxaban, apixaban, aspirin and no therapy in patients with nonvalvular atrial fibrillation (NVAF) is unknown.
Methods: Cost minimisation analysis using a cost impact model incorporating data from a network meta-analysis was used to systematically assess the costs of LAAC device implantation over a 10 year time horizon to determine the costs of LAAC in relation to all other treatment strategies in patients with nonvalvular AF at risk of stroke, with and without contraindications to anticoagulation. Complications and subsequent stroke rates were determined from our experience of 112 implants in 110 patients (Age 70.8±9.7, CHA2DS2-VASc 4.6±1.7, HAS-BLED 3.9±1.2). Device implantation and complication costs were obtained from UK NHS 2014 tariffs, while those for stroke were sourced from peer-reviewed literature. Overall cost-impact of LAAC was quantified as time to achieve cost parity with other strategies and cost saved over 10 years.
Results: Cost parity was achieved between 4.8 (vs Dabigatran 110mg) to 7.3 (vs Warfarin) years. Cost saving over 10 years ranged between 26.4% against PROTECT AF data (£9,933.82 vs £13,504.16) and 46.7% against Dabigatran 110mg (£9,933.82 vs £18,633.71).
Conclusion: LAAC in real world practice can substantially reduce costs relative to all other treatment strategies, including clinical trial data of LAAC, over a relatively short time horizon for patients at risk with NVAF.
[Show abstract][Hide abstract] ABSTRACT: Congenital left ventricular diverticula are an uncommon cardiac malformation. Although they may be asymptomatic, their presence is important to note as they are associated with systemic embolization of mural thrombus, valvular regurgitation, heart failure, focal ventricular arrhythmias, and sudden death.
We describe a case of an asymptomatic pilot with a significant burden of ventricular ectopy. The diagnosis of a large left ventricular diverticulum was made by cardiac CT and confirmed by cardiac magnetic resonance imaging. No specific treatment was warranted; however, regular on-going follow up was required.
It is important to seek out a structural cause for frequent ventricular ectopy even in the absence of symptoms. Transthoracic echocardiography is not always able to delineate the entire left ventricular cavity and other imaging modalities such as ECG-gated cardiac CT or gated MRI may need to be used in conjunction to permit assessment for the presence of structural heart disease in the whole heart. Aircrew with a high burden of ectopy require regular follow-up for complications such as more malignant dysrhythmias or LV impairment. In some cases, pharmacological or even surgical treatment is warranted, which may have a significant bearing for the future licensing of aircrew.
Aviation Space and Environmental Medicine 04/2014; 85(4):462-5. DOI:10.3357/ASEM.3807.2014 · 0.88 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Renal denervation is increasingly being adopted as a treatment option in patients with resistant hypertension. The long-term safety of this procedure is unknown. Though the procedure interrupts the sympathetic nerves at the renal level, it also has effects on other organ beds, notably the heart and vasculature. These effects have been purported to be clinically beneficial and thus formed a rationale for examining the role of renal denervation in other conditions, including heart failure, arrhythmia, obstructive sleep apnoea and the metabolic syndrome. There is a theoretical concern that attenuating the renal sympathetic nerves might cause orthostatic hypotension or syncope. From the limited data available from hypertension trials, the procedure has not been associated with excessive episodes of syncope and this is supported by mechanistic tilt table data in asymptomatic patients. Ultimately, the safety of this technique will only be established once we have larger phase III/IV studies.
International journal of cardiology 01/2014; 172(1). DOI:10.1016/j.ijcard.2013.12.163 · 4.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: -The role of subsequent atrial tachycardias (AT) in the context of persistent atrial fibrillation (AF) remains undetermined. This study evaluated the prognostic role of subsequent ATs for arrhythmia recurrences following catheter ablation of persistent AF.
-A total of 110 patients with persistent AF (63±9 y, 22 female, 61 long-lasting persistent AF) underwent pulmonary vein isolation followed by electrogram-guided ablation. After AF terminated to AT, patients were separated by the randomization protocol to receive either direct cardioversion (group A) or further ablation of subsequent ATs to sinus rhythm (SR) (group B). After a mean follow-up (FU) of 20.1±13.3 months after the first procedure, significantly more group B patients were in SR as compared to patients in group A (30 (57%) vs. 18 (34%), p=0.02). Moreover, recurrences of AF were significantly less frequent of group B than in group A patients (10 (19%) vs. 26 (49%), p=0.001). After the last procedure (FU 34.0±6.4 months), significantly more group B patients were free of AF as compared to patients of group A (49 (92%) vs. 39 (74%), p=0.01). The proportion of AT recurrences did not differ between the two groups after the first and final procedure. The strongest predictor for an arrhythmia free survival after a single procedure was randomization to the procedural endpoint of termination to SR by elimination of subsequent ATs (p=0.004).
-Catheter ablation of subsequent ATs increases freedom from AF but not AT, suggesting a contributing role of subsequent ATs in the mechanisms of persistent AF. Clinical Trial Registration-URL: http://www.clinicaltrials.gov; Unique identifier: NCT01896570.
[Show abstract][Hide abstract] ABSTRACT: Ivabradine, an I(f) current blocker, has shown promising results in treatment of postural orthostatic tachycardia syndrome (POTS). There is a subgroup of vasovagal syncope (VVS) patients, who demonstrate sinus tachycardia before collapse on tilt testing mimicking some features of POTS. These patients may also respond to ivabradine therapy.University Hospital Syncope Clinic where ivabradine was prescribed in a prospective fashion on humanitarian grounds between October 2008 and December 2011.METHODS AND RESULTS: Twenty-five patients of mean age 33±years presenting syncope in all and palpitation in 23, duration 9±years underwent tilt testing with reproduction of usual symptoms including tachycardia preceding collapse. Ivabradine was prescribed in doses of 5-20 mg/day, mean 10.7 mg, as once or twice daily medication. The response to treatment was classified as deterioration in none, no change in 5, improvement in 10, and symptoms abolished in 8 patients. Side effects were minimal; one patient required discontinuation.CONCLUSION: In this pilot study of ivabradine, in patients with VVS, of patients who demonstrated sinus tachycardia before collapse on tilt, 72% reported a marked benefit or complete resolution of symptoms. The drug was well tolerated. A randomized controlled trial against placebo is justified.
[Show abstract][Hide abstract] ABSTRACT: Background:
Contact force (CF) sensing technology allows real time CF measurement during catheter ablation. We hypothesised that the use of CF technology during pulmonary vein isolation (PVI) for atrial fibrillation (AF) would translate into lower acute pulmonary vein (PV) reconnection rates.
Methods and results:
Symptomatic AF patients were treated in two groups, 'unblinded' and 'blinded', each containing 20 patients undergoing first time PVI. An irrigated radiofrequency CF sensing catheter was used in both groups. In the 'unblinded' group, the operator could view the CF value during mapping and ablation in real time. In the 'blinded group', the operator was 'blinded' to this information during the procedure, although the data were recorded. All 80 PVs were successfully isolated with exit and entrance block re-tested after 1h with adenosine. There was a significant association between blinding and the rate of acute PV reconnection. 17/80 (21%) of the PVs in the blinded subjects had a reconnection while 3/80 (4%) of the PVs in the unblinded subjects had a reconnection (p=0.001). Blinding the operator resulted in lower mean CF overall (11.6g (10.5, 12.9 g) vs. 14.4 g (13.3, 15.7 g); p=0.002). Sites where applied CF was significantly lower than others were usually the sites where reconnection occurred: these were the ridge between the left upper PV and appendage, and the right carina.
CF data identified key areas where CF was poor. These were the areas of acute reconnection. Availability of real time CF information during PVI was associated with a significantly lower acute pulmonary vein reconnection rate.
International journal of cardiology 12/2012; 168(2). DOI:10.1016/j.ijcard.2012.11.072 · 4.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Purpose: Atherosclerotic plaques progress in a highly individual manner. Plaque eccentricity has been associated with a rupture-prone phenotype and adverse coronary events in humans. Endothelial shear stress (ESS) critically determines plaque growth and low ESS leads to high-risk lesions. However, the factors responsible for rapid disease progression with increasing plaque eccentricity have not been studied. We investigated in vivo the effect of local hemodynamic and plaque characteristics on progressive luminal narrowing with increasing plaque eccentricity in humans.
Methods: Three-dimensional coronary artery reconstruction using angiographic and intravascular ultrasound data was performed in 374 patients at baseline (BL) and 6-10 months later (FU) to assess plaque natural history as part of the PREDICTION Trial. A total of 874 coronary arteries were divided into consecutive 3-mm segments. We identified 408 BL discrete luminal narrowings with a throat in the middle surrounded by gradual narrowing proximal and distal to the throat. Local BL ESS was assessed by computational fluid dynamics. The eccentricity index (EI) at BL and FU was computed as the ratio of max to min plaque thickness at the throat. Mixed-effects logistic regression was used to investigate the effect of BL variables on the combined endpoint of substantial worsening of luminal narrowing (decrease in lumen area >1.8 mm2 or >20%) with an increase in plaque EI.
Results: Lumen worsening with an increase in plaque EI was evident in 73 luminal narrowings (18%). Independent predictors of worsening lumen narrowing with plaque EI increase were low BL ESS (<1 Pa) distal to the throat (odds ratio [OR] =2.2 [95% CI: 1.3-3.7]; p=0.003) and large BL plaque burden (>51%) at the throat (OR=1.7 [95% CI: 1.0-2.8]; p=0.051). The incidence of worsening lumen narrowing with increasing plaque eccentricity was 30% in the presence of both predictors versus 15% in luminal narrowings without this combination of characteristics (OR=2.4 [95% CI: 1.4-4.3]; p=0.002).
Conclusions: Low local ESS independently predicts areas with rapidly progressive luminal narrowing and increasing plaque eccentricity. Coronary regions manifesting an abrupt anatomic change, i.e., at highest risk to cause an adverse event, can be identified early by assessment of ESS and plaque burden.
[Show abstract][Hide abstract] ABSTRACT: Patients can expect a cure from atrial fibrillation (AF) with ablation. Procedural safety and success depend on patient comfort, compliance, and immobility. This is difficult to achieve with benzodiazepine and opiate boluses that are the mainstay of current practice. We sought to determine the safety and efficacy of propofol infusion sedation administered to patients without assisted ventilation for AF ablation.
Procedural data from 1000 consecutive patients undergoing AF ablation were analysed. Sedation with 2% propofol was used in all procedures without assisted ventilation and was administered, monitored, and controlled by electrophysiologists. Primary outcome measures were adverse sedative affects including (i) respiratory depression (SpO(2)< 90% for >20 s) and (ii) persistent hypotension [systolic blood pressure (SBP)<90 mmHg at minimum sedation level]. Secondary endpoints included full recovery within 60 min and procedural complications. Of 1000 ablations, 506 ablations were performed for persistent and 494 for paroxysmal AF. Average patient age was 60.1 ± 11.3 years (72.3% male). Propofol was commenced in all patients at a mean infusion rate of 18.5 ± 4.8 mL/h with a mean baseline SBP of 140.3 ± 19.9 mmHg. Mean procedure time was 148.7 ± 57.7 min. Adverse sedative effects necessitating cessation of propofol and switch to midazolam bolus sedation occurred in 15.6% of patients (13.6% due to persistent hypotension, 1.9% due to respiratory depression, and 0.1% due to hypersalivation). Patients who had persistent hypotension were older (62.9 ± 11.2 vs. 60.0 ± 11.4 years, P= 0.011) and more likely to be female (39.5 vs. 23.7%, P< 0.001) than those who tolerated propofol. Patient age correlated to maximum blood pressure drop with propofol (R(2)= 0.101, P< 0.001) and inversely correlated to mean propofol infusion rate (R(2)= 0.066, P< 0.001). No procedures were abandoned due to adverse effects of sedation. All patients recovered within 60 min. Serious procedural complications, unrelated to sedation, occurred in 0.5%, all of whom had pericardial tamponade successfully treated with percutaneous pericardiocentesis.
Sedation with 2% propofol infusion administered by cardiologists without assisted ventilation is safe, effective, and practical for use in AF ablation without serious or residual complications. In this setting, persistent hypotension is the most common acute adverse effect requiring cessation of propofol in ∼14%.
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to assess the role of a non-pharmacological approach on the frequency of traumatic injuries and syncope recurrence in patients with vasovagal syncope and normal hearts. We report the experience in our syncope centre with a standardized education and teaching protocol for patients with vasovagal syncope. The treatment of vasovagal syncope is often complex and discouraging. Besides medical options, behaviour modification is a main component of therapy but has no statistical evidence to support its use.
Between January 1999 and September 2006, we prospectively enrolled all patients with vasovagal syncope. The patients were counselled about the benign nature of their disease. Specific recommendations were made according to a standardized education protocol established at our syncope centre. A pre-/post-study was conducted to investigate the effectiveness of our approach on syncope recurrence and frequency of injury as the study endpoints. Complete follow-up data were available from 85% of the study population (316 of 371) after a mean time of 710 ± 286 days (mean age 50 years; standard deviation ± 18 years, 160 female). Eighty-seven patients (27.5%) had a syncope recurrence with 22 suffering an injury during syncope. During the follow-up period, the syncope burden per month was significantly reduced from 0.35 ± 0.03 at initial presentation to 0.08 ± 0.02 (P< 0.001). The frequency of traumatic syncope was significantly lower at the time of recurrence compared with the initial presentation (25 vs. 42%; McNemar's test P= 0.02).
A standardized education protocol significantly reduces traumatic injuries and syncope recurrence in patients with vasovagal syncope.
[Show abstract][Hide abstract] ABSTRACT: External biphasic electrical cardioversion (CV) is a standard treatment option for patients suffering from acute symptoms of atrial fibrillation (AF). Nevertheless, CV is not always successful, and thus strategies to increase the success rate are desirable.
The purpose of this study was to evaluate the effect of intravenously administered K/Mg solution on the biphasic CV energy threshold and success rate to restore sinus rhythm (SR) in patients with AF.
The study consisted of 170 patients with persistent AF. The patients were randomly assigned to undergo biphasic CV either with (n = 84) or without (n = 86) pretreatment with K/Mg solution. An energy step-up protocol of 75, 100, and 150 W (J) was used.
Biphasic CV of AF was effective in 81 (96.4%) patients in the pretreatment and 74 (86.0%) patients in the control group (P = 0.005). The effective energy level required to achieve SR was significantly lower in the pretreated group (140.8 ± 26.9 J vs 182.5 ± 52.2 J, P = 0.02). No K/Mg-solution-associated side effects such as hypotension or bradycardia were observed.
Administration of K/Mg solution positively influences the success rate of CV in patients with persistent AF. Furthermore, significantly less energy is required to successfully restore SR and therefore K/Mg pretreatment may facilitate SR restoration in patients undergoing CV for AF.
[Show abstract][Hide abstract] ABSTRACT: IntroductionVisualisation of the ablation-related atrial scar using delayed-enhanced MRI (DE-MRI) may reveal important underlying causes for atrial fibrillation (AF) recurrence following ablation. In order to develop and objective method for delineating ablation-scar we compared pre and post DE-MRI after Cryo-balloon lesion on the basis that a more predictable lesion set would be created for validation.Methods and Results12 patients undergoing cryoablation for PAF were enrolled in the study, and underwent pre-ablation DE-MRI scans. Pulmonary vein isolation (PVI) was confirmed in all patients at the end of the cryoablation procedure using a circular mapping catheter. Additional ablation by RF or Freezer Max was required to achieve PVI in 59%. No ablation was performed in any region other than the PV ostia. Post-ablation DE-MRI was performed at 3 months. An automatic segmentation of the LA was produced with custom software from the MRA sequence. The preablation and postablation free breathing late gadolinium enhanced sequence was registered to the MRA and the maximum intensity within the LA wall was projected onto the post ablation LA surface. The blood pool was identified automatically using custom software as the region 1 cm inside the wall of the LA, and its mean (BPM) and SD used as a baseline. To identify a universal threshold for scar, regions of brightest myocardium were initially selected in pre and post ablation MRIs. The brightest regions were 1.9±1.2 vs 8.7±3.1 SDs above the BPM in pre-and post-ablation MRIs respectively (p=0.001). A threshold of 5 SDs above the BPM was therefore programmed into our custom software to identify regions of scar for all patients. The ostial regions were defined as extending 1 cm both proximal and distal to the PV–LA junction, and selected manually for left and right sided veins prior to scar projection. (See Abstract 149 figure 1). The scar proportion within these regions was calculated using commercially available software ITK-SNAP. Total LA scar proportion was 0.2±0.02% vs 6.3±0.75% in pre and post ablation scans respectively. The increase in scar seen in the PV ostia was 24.6±1.38% compared with 2.6±1.28% in the rest of the LA (p=0.01) (See Abstract 149 figure 2).Comparison of pre-ablation and post-ablation %scar using fixed threshold.Conclusion
We have demonstrated the feasibility an objective, automated method of DE-MRI analysis of left atrial ablation-scar. This technique will now need to be validated against clinical outcomes.
[Show abstract][Hide abstract] ABSTRACT: Stepwise ablation is an effective treatment for persistent atrial fibrillation (AF), although it often requires multiple procedures to eliminate recurrent arrhythmias.
This study evaluated single- and multiple-procedure long-term success rates and potential predictors of a favorable single-procedure outcome of stepwise ablation for persistent AF.
This study comprised 395 patients with persistent AF (duration 16 months) undergoing de novo catheter ablation using the stepwise approach. Procedural success was defined as the absence of any arrhythmia recurrence. Patient characteristics and electrophysiological parameters were analyzed with respect to single- and multiple-procedure outcomes.
After a follow-up of 27 ± 7 months, 108 (27%) patients were free of arrhythmia recurrences with a single procedure. After 2.3 ± 0.6 procedures, 312 (79%) patients were free of arrhythmia with concomitant antiarrhythmic treatment in 38% (23% on β-blocker). Female gender, duration of persistent AF, and congestive heart failure were predictive for the outcome after first ablation. However, the strongest predictors for single-procedure success were longer baseline AF cycle length (CL) and procedural AF termination. Moreover, procedural AF termination during the index procedure also predicted a favorable outcome after the last procedure, while the existence of congestive heart failure was associated with an increased risk for eventual arrhythmia recurrences.
Single-procedure long-term success is anticipated in approximately a quarter of patients undergoing de novo ablation of persistent AF. Baseline AFCL emerged as the strongest predictor of single-procedure success, while AF termination during index ablation predicts the overall outcome. However, an overall success rate of 79% is achievable with multiple procedures.
Heart rhythm: the official journal of the Heart Rhythm Society 04/2011; 8(9):1391-7. DOI:10.1016/j.hrthm.2011.04.012 · 5.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Catheter ablation (CA) is considered the treatment of choice for patients with atrioventricular nodal reentrant tachycardia (AVNRT). However, there is a tendency to avoid CA in the elderly because of a presumed increased risk of periprocedural atrioventricular (AV) nodal block.
The purpose of this prospective registry was to assess age-related differences in the efficacy and safety of CA within a large population with AVNRT.
A total of 3,234 consecutive patients from 48 German trial centers who underwent CA of AVNRT between March 2007 and May 2010 were enrolled in this study. The cohort was divided into three age groups: <50 years (group 1, n = 1,268 [39.2%]; median age = 40 [30.0-45.0] years, 74.1% women), 50-75 years old (group 2, n = 1,707 [52.8%]; 63.0 [58.0-69.0] years, 63.0% women), and > 75 years old (group 3, n = 259 [8.0%]; 79.0 [77.0-82.0] years, 50.6% women).
CA was performed with radiofrequency current (RFC) in 97.7% and cryoablation technology in 2.3% of all cases. No differences were observed among the three groups with regard to primary CA success rate (98.7% vs. 98.8 % vs. 98.5%; P = .92) and overall procedure duration (75.0 minutes [50.0-105.0]; P = .93). Hemodynamically stable pericardial effusion occurred in five group 2 (0.3%) and two group 3 (0.8%) patients but in none of the group 1 (P <.05) patients. Complete AV block requiring permanent pacemaker implantation occurred in two patients in group 1 (0.2%) and six patients in group 2 (0.4%) but none in group 3 (P = 0.41). During a median follow-up period of 511.5 days (396.0-771.0), AVNRT recurrence occurred in 5.7% of all patients. Patients >75 years (group 3) had a significantly longer hospital stay (3.0 days [2.0-5.0]) compared with group 1 (2.0 days [1.0-2.0]) or group 2 (2.0 days [1.0-3.0]) patients (P <.0001).
CA of AVNRT is highly effective and safe and does not pose an increased risk for complete AV block in patients over 75 years of age, despite a higher prevalence of structural heart disease. Antiarrhythmic drug therapy is often ineffective in this age group; thus, CA for AVNRT should be considered the preferred treatment even in elderly patients.
Heart rhythm: the official journal of the Heart Rhythm Society 02/2011; 8(7):981-7. DOI:10.1016/j.hrthm.2011.02.008 · 5.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Pulmonary veins (PVs) usually drain into the left atrium (LA) and are frequently targeted for electrical isolation, since it became evident that PVs may trigger and maintain paroxysmal atrial fibrillation (AF). We present a patient with right-sided PVs anomalously connecting to the right atrium with lack of electrical PV-atrial connection. Therefore, isolation of the left veins was performed resulting in freedom from AF as shown during a midterm follow-up. These findings indicate that PV connection to the LA may be a prerequisite for the arrhythmogenic properties of the PVs causing AF.
[Show abstract][Hide abstract] ABSTRACT: Vasovagal syncope is a common cause of recurrent syncope. Clinically, these episodes may present as an isolated event with an identifiable trigger, or manifest as a cluster of recurrent episodes warranting intensive evaluation. The mechanism of vasovagal syncope is incompletely understood. Diagnostic tools such as implantable loop recorders may facilitate the identification of patients with arrhythmia mimicking benign vasovagal syncope. This review focuses on the management of vasovagal syncope and discusses the non-pharmacological and pharmacological treatment options, especially the use of midodrine and selective serotonin reuptake inhibitors. The role of cardiac pacing may be meaningful for a subgroup of patients who manifest severe bradycardia or asystole but this still remains controversial.
World Journal of Cardiology (WJC) 10/2010; 2(10):308-15. DOI:10.4330/wjc.v2.i10.308 · 2.06 Impact Factor