Cardiac resynchronization therapy in patients with a coronary sinus reducer: a case series.

Background: Reducing venous drainage of the coronary sinus is a promising intervention for refractory angina. Coronary Sinus Reducer (CSR) System™ effectively treats patients with refractory angina, possibly by increasing coronary collateral circulation, and leads to an improvement in their symptoms and quality of life. In patients with impaired left ventricular function and electrocardiographic dyssynchrony, cardiac resynchronization therapy (CRT) is an established treatment. However, there is only one published case report of CRT in a patient implanted with a CSR system. We present the first case series of CRT in patients implanted with the CSR system. Case summary: This case series describes three patients. The first case demonstrated that CRT is feasible in patients implanted with a CSR system. The second case is the first report of a left ventricular lead extraction after CSR, and the third case was complicated due to the patient's medical history; however, CSR system implantation was feasible without major complications. Discussion: Our results suggest that CRT is feasible in patients implanted with a CSR system, and lead extraction after CSR system implantation is possible. However, lead extraction in cases of severe adhesions around the CSR system and the coronary sinus may be associated with a high risk of complications; alternative options should be discussed at an early stage.

Impact of Catheter Ablation on Arrhythmia Burden in Patients With Shock-Resistant Persistent Atrial Fibrillation.

BACKGROUND: Persistent shock-resistant atrial fibrillation (AF) is a challenging entity, with modest results from catheter ablation according to conventional survival analysis. OBJECTIVES: The aim of this study was to determine the effect of catheter ablation on atrial tachyarrhythmia (ATA) burden in persistent AF patients undergoing first-time ablation with the use of an implantable cardiac monitor (ICM). METHODS: Patients with drug-resistant ongoing persistent AF and at least 1 previous failed cardioversion were implanted with an ICM 2 months before the procedure. All patients underwent pulmonary vein isolation with or without additional substrate ablation depending on the presence of self-terminating AF on ICM and left atrium size. Median AF burden before and after ablation, off antiarrhythmic medication, was determined from ICM recordings after review by 2 independent investigators. RESULTS: Sixty patients were recruited (mean age 66 ± 9 years, 70% male). Mean left atrial diameter was 48 ± 6 mm and median CHA2DS2VASc score was 2. Ten patients (17%) unexpectedly demonstrated self-terminating AF before ablation. The median burden of ATA before ablation was 100% (95% CI: 19.6%-100%), decreasing to 0% (95% CI: 0%-95.8%) after ablation during the post-blanking follow-up period (median reduction 100%; 95% CI: 4%-100%; P < 0.001). Twenty-seven patients (45%) experienced recurrent ATA during 12-month follow-up. In these patients, median burden before ablation was 100% (95% CI: 26.9%-100%), decreasing to 11.4% (95% CI: 0.35%-99.7%) after ablation (P < 0.001). Quality of life improved significantly from baseline, driven by lack of recurrence. CONCLUSIONS: Patient-tailored catheter ablation results in a significant reduction in ATA burden (off antiarrhythmic medication) in shock-resistant persistent AF patients using ICMs implanted 2-months pre-procedure. These data suggest that conventional arrhythmia-free survival analysis does not capture the true impact of catheter ablation in this challenging cohort.

Very High-Power Ablation for Contiguous Pulmonary Vein Isolation: Results From the Randomized POWER PLUS Trial.

BACKGROUND: Very high-power, short-duration (90-W/4-second) ablation for pulmonary vein isolation (PVI) may reduce procedural times. However, shorter applications with higher power may impact lesion quality. OBJECTIVES: In this multicenter, randomized controlled trial, the authors compared procedural efficiency, efficacy, and safety of PVI using 90-W/4-second ablation to 35/50-W ablation. METHODS: Patients with paroxysmal or persistent atrial fibrillation undergoing first-time PVI were randomized to pulmonary vein encirclement with contiguous applications using very high-power, short-duration applications (90 W over 4 seconds) or 35/50-W applications (titrated up to ablation index >550 anteriorly and >400 posteriorly). Prospective endpoints were procedural efficiency (procedure time and first-pass isolation), safety (including esophageal endoscopic evaluation), and 6-month effectiveness using repetitive Holter monitoring. RESULTS: A total of 180 patients were randomized, 90 to the 90-W group (mean age: 64.2 ± 8.9 years) and 90 to the 35/50-W group (mean age: 62.3 ± 10.8 years). Procedural time was shorter in the 90-W group vs the 35/50-W group (70 [IQR: 60-80] minutes vs 75 [IQR: 65-88.3] minutes; P = 0.009). A nonsignificant trend towards lower rates of first-pass isolation was seen in the 90-W group (83.9% vs 90%; P = 0.0852). No major complications were observed in both groups with esophageal injury occurring in 1 patient per group. At 6 months, 17% of patients in the 90-W group vs 15% in the 35/50-W group experienced recurrent arrhythmia (P = 0.681). CONCLUSIONS: Contiguous ablation using very high-power, short-duration applications results in a significant but modest reduction in procedure time with similar safety and 6-month efficacy vs a conventional approach. A hybrid approach combining both ablation modalities might be the most optimal strategy. (POWER PLUS [Very High Power Ablation in Patients With Atrial Fibrillation Schedule for a First Pulmonary Vein Isolation]; NCT04784013).

Evaluation of a standardized approach using optimized and contiguous RF applications for electrical isolation of the superior vena cava.

The superior vena cava (SVC) is well described as one of the most common non-pulmonary vein (PV)-triggers for atrial tachyarrhythmias (ATA). In our study we evaluated a standardized approach for electrical isolation of the SVC from the right atrium using a horseshoe-shaped lesion set with optimized and contiguous ostial RF lesions. The results are promising, demonstrating a very high rate of acute SVC isolation in a safe and time efficient manner (mostly less than 10 min).

Performance and safety of temperature- and flow-controlled radiofrequency ablation for ventricular arrhythmia.

AIMS: High-power ablation is effective for ventricular arrhythmia ablation; however, it increases the risk of steam pops. The aim of this study was to define the safety and efficacy of QMODE ablation in the ventricle and the risk of steam pop. METHODS AND RESULTS: Consecutive patients undergoing ventricular ablation using QDOT were included in a prospective single-centre registry. Procedural data, complications, and follow-up were systematically analysed and compared with a historical ventricular tachycardia (VT) and premature ventricular complexes (PVC) cohort ablated using STSF. QMODE (≤50 W) ablation was performed in 107 patients [age 62 ± 13 years; 76% male; VT (n = 41); PVC (n = 66)]. A total of 2456 applications were analysed [power: 45.9 ± 5.0 W with minimal power titration (90% > 95% max power); duration 26 ± 8 s; impedance drop 9.4 ± 4.7 Ω; ablation index: 569 ± 163; mean-max temperature 44.3 ± 2.6°C]. Ventricular tachycardia ablation was associated with shorter radiofrequency (RF) time and a trend towards shorter procedure times using QDOT (QDOT vs. STSF: 20.1 ± 14.7 vs. 31 ± 17 min; P = 0.002, 151 ± 59 vs. 172 ± 48 min; P = 0.06). Complications, VT recurrence, and mortality rates were comparable (QDOT vs. STSF: 2% vs. 2%; P = 0.9, 24% vs. 27%; P = 0.82, and 2% vs. 4%; P = 0.67). Five audible steam pops (0.02%) occurred. Premature ventricular complex ablation was associated with comparable RF and procedure times (QDOT vs. STSF: 4.8 ± 4.6 vs. 3.9 ± 3.1 min; P = 0.25 and 96.1 ± 31.9 vs. 94.6 ± 24.7 min; P = 0.75). Complication and PVC recurrence were also comparable (QDOT vs. STSF: 0% vs. 3%; P = 0.17 and 19% vs. 22%; P = 0.71). CONCLUSION: Ventricular ablation using QMODE ≤ 50 W is safe and effective for both VT and PVC ablation and is associated with a low risk for steam pop.

Early Experience with the Biotronik Protego ICD Lead.

Background: In the last decade, newer generation ICD leads have been developed based on mechanistic insides of priorly failing leads. The aim of our study was to assess the long-term performance and mechanisms of failure of the 2013-introduced Biotronik Protego ICD lead in a real-world population. Methods: All patients, who underwent implantation of a Protego ICD lead at the Heart Centre Lucerne (Lucerne, Switzerland) between November 2013 and March 2017, were followed up with semi-annual device-controls. The primary endpoint was defined as lead failure, secondary endpoints compromised all-cause death, (in)appropriate shocks and the need for reintervention. Results: A total of 64 patients (mean age 66.7 ± 8.7 years, 30% female) underwent implantation of a Protego ICD lead: 78% for primary prevention, 53% had underlying ischemic heart disease, and 40.6% had a dilated cardiomyopathy (DCM). Mean left ventricular ejection fraction (LVEF) was 32.6 ± 10.5%. A total of 24 patients were treated with cardiac resynchronization therapy (CRT), and their baseline LVEF improved from 27.8 ± 7.3% before to 39.8 ± 12.5 after implantation (p < 0.001). Mean time to follow-up was 5.5 ± 0.9 years. Overall, 14 patients (26.6%) suffered from at least one episode of sustained ventricular tachycardia; in total 10 patients (15.6%) died. Two patients experienced lead failure due to lead fracture after 5.5 and 5.7 years, which was clinically apparent by an abrupt rise in lead impedance (>2000 Ω) and by repetitive inappropriate shocks, respectively. Conclusions: In this retrospective observational study, the calculated annual lead failure rate of the Biotronik Protego ICD lead was 0.59% per patient­thus, the durability and long-term performance seem to be promising.

Long-term follow-up after the use of the as low as reasonably achievable radiation protocol in patients with symptomatic supraventricular tachycardia.

INTRODUCTION: Catheter ablation is an effective treatment modality for patients with symptomatic supraventricular tachycardia (SVT), such as atrioventricular nodal re-entrant tachycardia (AVNRT) and typical atrial flutter (TAF). With increasingly invasive electrophysiological procedures and continuous development of ablation techniques, the aim is to reduce radiation doses for patients and the electrophysiological team. Modern methods that combine the "as low as reasonably achievable" (ALARA) protocol and three-dimensional mapping systems are now state-of-the-art procedures in the treatment of arrhythmia. This study aimed to compare the effectiveness and long-term success of the ALARA approach compared to those of conventional therapy, without using modern mapping systems. METHODS: Sixty-one patients with symptomatic SVT (37 with AVNRT, 19 with isthmus-dependent counter-clockwise TAF, and five with other SVTs) were randomised into two groups: the ALARA and conventional groups. All patients underwent successful SVT ablation. Clinical and remote follow-up was available for 59 patients after a mean period of 3.2 years. RESULTS: The mean fluoroscopy time was significantly shorter in the ALARA group (1.1 min vs. 8.4 min, p < 0.01). Regarding complications and recurrences, during a median follow-up period of 3.2 years, eight patients (13.5%) had recurrences, all of which occurred in the conventional group. CONCLUSION: This study confirmed a significantly lower radiation burden for patients and the entire electrophysiological team with the ALARA approach and a significantly increased risk of recurrence and complications with the conventional approach. The reduction in radiation time and high long-term success indicate the utility of the ALARA protocol in daily practice.

Vein of Marshall Ethanol Infusion as First Step for Mitral Isthmus Linear Ablation.

OBJECTIVES: In this study, the authors sought to investigate the added value of vein of Marshall ethanol infusion (VOMEt) as first step in facilitating radiofrequency (RF)-guided mitral isthmus (MI) block. BACKGROUND: Achieving MI block with the use of RF ablation is challenging. METHODS: Seventy patients planned for MI ablation were randomized 1:1 to VOMEt as a first step preceding RF (endocardial and epicardial, VOMFIRST group) vs RF ablation as a first step preceding VOMEt (RFFIRST group). The study end point was incidence of MI block after RF ablation and after the 2 steps. RESULTS: In VOMFIRST, VOMEt was successful in 30/35 patients (86%) resulting in a low-voltage area of 12 ± 7.4 cm2 and MI block in 2/35 patients (6%). VOMFIRST, compared with RFFIRST, was associated with higher incidence of MI block after endocardial (46% vs 11%; P < 0.001) and epicardial ablation (94% vs 43%; P < 0.001), with fewer endocardial applications (4 vs 11 vs 4; P < 0.001) and similar epicardial applications (7 vs 8; P = 0.68). Incidence of MI block after the 2 steps was 94% vs 63% (P = 0.001) in VOMFIRST vs RFFIRST, respectively. Additional touch-up RF ablation in both groups resulted in final MI block in all but 1 patient (99%). CONCLUSIONS: VOMEt as a first step in RF-guided MI line ablation significantly reduced the number of RF applications needed to achieve MI block, even if the sequence of the ablation steps did not affect the final incidence of block. (Evaluation of Vein of Marshall Ethanol Infusion During Left Atrial Linear Ablation in Patients With Persistent Atrial Fibrillation [MARSHALINE]; NCT04124328).

Left bundle branch area pacing guided by continuous uninterrupted monitoring of unipolar pacing characteristics.

INTRODUCTION: During left bundle branch area pacing (LBBAP) lead implantation, intermittent monitoring of unipolar pacing characteristics confirms LBB capture and can detect septal perforation. We aimed to demonstrate that continuous uninterrupted unipolar pacing from an inserted lead stylet (LS) is feasible and facilitates LBBAP implantation. METHODS: Thirty patients (mean age 76 ± 14 years) were implanted with a stylet-driven pacing lead (Biotronik Solia S60). In 10 patients (comparison-group) conventional implantation with interrupted unipolar pacing was performed, with comparison of unipolar pacing characteristics between LS and connector-pin (CP)-pacing after each rotation step. In 20 patients (uninterrupted-group) performance and safety of uninterrupted implantation during continuous pacing from the LS were evaluated. RESULTS: In the comparison group, LS and CP-pacing impedances were highly correlated (R2 = 0.95, p < .0001, bias 12 ± 37 Ω) with comparable sensed electrograms and paced QRS morphologies. In the uninterrupted group, continuous LS-pacing allowed beat-to-beat monitoring of impedance and QRS morphology to guide implantation. This resulted in successful LBBAP in all patients, after a mean of 1 ± 0 attempts, with mean threshold 0.81 ± 0.4 V, median sensing 6.5 mV [IQR 4.4-9.5], and mean impedance 624 ± 101 Ω. Positive LBBAP-criteria were seen in all patients with median paced QRS duration of 120 ms [IQR 112-152 ms] and median pLVAT 73 ms [IQR 68-80.5 ms]. No septal perforation occurred. CONCLUSION: Unipolar pacing from the LS allows accurate determination of pacing impedance and generates similar paced QRS morphologies and sensed electrograms to CP pacing. Continuous LS pacing allows real-time monitoring of impedance and paced QRS morphology, which facilitates safe and successful LBBAP lead implantation.

Catheter Ablation in Persistent AF, the Evolution towards a More Pragmatic Strategy.

Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide and represents a heterogeneous disorder with a complex pathological basis. While significant technological advances have taken place over the last decade in the field of catheter ablation of AF, response to ablation varies and long-term success rates in those with persistent AF remain modest. Mechanistic studies have highlighted potentially different sustaining factors for AF in the persistent AF population with substrate-driven focal and re-entrant sources in the body of the atria identified on invasive and non-invasive mapping studies. Translation to clinical practice, however, remains challenging and the application of such mapping techniques to clinical ablation has yet to demonstrate a significant benefit beyond pulmonary vein isolation (PVI) alone in the persistent AF cohort. Recent advances in catheter and ablation technology have centered on improving the durability of ablation lesions at index procedure and although encouraging results have been demonstrated with early studies, large-scale trials are awaited. Further meaningful improvement in clinical outcomes in the persistent AF population requires ongoing advancement in the understanding of AF mechanisms, coupled with continuing progress in catheter technology capable of delivering durable transmural lesions.

Biosense Webster's QDOT Micro™ radiofrequency ablation catheter.

The QDOT Micro™ catheter (Biosense Webster, Inc., CA, USA) is a new radiofrequency ablation catheter based on the SmartTouch SF™ (Biosense Webster, Inc.). It combines diffuse external irrigation with six thermocouples located within the outer metal shell and three additional microelectrodes in a 3.5 mm-tip contact force radiofrequency catheter. This article focuses on the different characteristics of the catheter, which incorporates the ability of high power delivery, irrigation flow control based on temperature sensing through the six thermocouples and the generation of microelectrograms. An outline of its performance in preclinical and clinical setting is presented, showing promising results, especially concerning procedural efficiency and short-term safety. Additional studies need to confirm long-term effectiveness, and durability studies should evaluate whether superiority on a lesion quality level can be achieved.

Lay abstract Radiofrequency (RF) energy is the most widely used type of energy in the field of catheter ablation, an invasive treatment for heart rhythm disorders. In patients with atrial fibrillation (AF; the most frequent type of problem with the rhythm of the heart), catheter ablation aims at delivering RF energy around the pulmonary veins (PVs). PVs have been shown to contain AF triggers. Catheter ablation results in electrical isolation of the PV, making them less likely to trigger AF. The latest technical developments resulted in better success rate of the procedure (up to 90% success rate after 1 year follow-up) without increasing complication rates. During the last decade, the catheter used to isolate the PV has improved a lot and includes now contact force measurement in addition to the delivery mechanism for RF energy and can record the local electrical activity. The newly developed QDOT Micro™ catheter (Biosense Webster, Inc., CA, USA), presented in this article, combines different aspects of further technical development. These include the integration of smaller electrodes, resulting in higher local electrical signal resolution, more accurate feedback of local tissue temperature during the procedure and the ability to use higher RF power which reduces the RF delivery time and therefore reduced the duration of the procedure. An outline of its performance in preclinical and clinical setting is presented in this paper. These studies have shown promising results, especially concerning procedural efficiency and short-term safety. However, additional studies need to confirm long-term treatment success and potential superiority in comparison with other ablation approaches.

Repositioning and extraction of stylet-driven pacing leads with extendable helix used for left bundle branch area pacing.

Conventional stylet-driven leads with extendable helix can be implanted successfully for left bundle branch area pacing (LBBAP) with a low acute complication rate. We report two cases in which lead repositioning after a first unsuccessful attempt to LBBAP was associated with fracture of the helix rotating mechanism and failure to fully extract the pacing lead.

Predictors of recurrence after durable pulmonary vein isolation for paroxysmal atrial fibrillation.

AIMS: Catheter ablation of paroxysmal atrial fibrillation (AF) reduces AF recurrence, AF burden, and improves quality of life. Data on clinical and procedural predictors of arrhythmia recurrence are scarce and are flawed by the high rate of pulmonary vein reconnection evidenced during repeat procedures after pulmonary vein isolation (PVI). In this study, we identified clinical and procedural predictors for AF recurrence 1 year after CLOSE-guided PVI, as this strategy has been associated with an increased PVI durability. METHODS AND RESULTS: Patients with paroxysmal AF, who received CLOSE-guided PVI and who participated in a prospective trial in our centre, were included in this study. Uni- and multivariate models were plotted to find clinical and procedural predictors for AF recurrence within 1 year. Three hundred twenty-five patients with a mean age of 63 years (CHA2DS2VASc 1 [1-3], left atrium diameter 41 ± 6 mm) were included. About 60.9% were male individuals. After 1 year, AF recurrence occurred in 10.5% of patients. In a binary logistic regression analysis, the diagnosis-to-ablation time (DAT) was found to be the strongest predictor of AF recurrence (P = 0.011). Diagnosis-to-ablation time ≥1 year was associated with a nearly two-fold increased risk for developing AF recurrence. CONCLUSION: The DAT is the most important predictor of arrhythmia recurrence in low-risk patients treated with durable pulmonary vein isolation for paroxysmal AF. Whether reducing the DAT could improve long-term outcomes should be investigated in another trial.

Prospective Randomized Evaluation of High Power During CLOSE-Guided Pulmonary Vein Isolation: The POWER-AF Study.

BACKGROUND: CLOSE-guided atrial fibrillation (AF) ablation is based on contiguous (intertag distance ≤6 mm), optimized (Ablation Index >550 anteriorly and >400 posteriorly) point-by-point radiofrequency lesions. The optimal radiofrequency power remains unknown. METHODS: The POWER-AF study is a prospective, randomized controlled monocentric study including patients with paroxysmal AF, planned for first CLOSE-guided pulmonary vein isolation using a contact force radiofrequency catheter (Thermocool SmartTouch, Biosense Webster, Inc, Irvine, CA). A total of 100 patients were randomized into 2 groups (1:1). The control group received AF ablation using the standard CLOSE protocol (35 W), whereas in the experimental group, pulmonary vein isolation was performed using high power (45 W). Endoscopic evaluation was performed in patients with intraesophageal temperature rise >38.5 °C. RESULTS: The resulting sample size was 96 (48+48) patients. In the high power group, shorter procedure time (80 versus 102 minutes, P<0.001), shorter total radiofrequency application time (16 versus 26 minutes, P<0.001), and radiofrequency time per application (26 versus 37 s anteriorly, P<0.001 and 13 versus 17 s posteriorly, P<0.001) were observed. Endoscopic evaluation (performed in 19/48 versus 25/48 patients respectively, P=0.31) showed an ulcerative perforation in a high power group patient (treated by endoscopic stenting and normalization after ≈4 months) and a superficial ulcerative lesion in a control group patient (conservative treatment). Both occurred following excessive Ablation Index applications (up to 460 and 480, respectively) with excessive contact force (30 g on average, with peaks up to 50 g). Six-months AF recurrence was not significantly different (10% in high power versus 8% in control, P=0.74). CONCLUSIONS: This randomized controlled study shows that a 45 W radiofrequency power CLOSE protocol in patients with paroxysmal AF significantly increases the global procedural efficiency with similar midterm efficacy. However, our study showed a narrower safety margin and a limited increased efficiency at the posterior wall using high power. This advocates against the use of high power in the region neighboring the esophagus.

Evaluation of higher power delivery during RF pulmonary vein isolation using optimized and contiguous lesions.

AIMS: "CLOSE"-guided pulmonary vein isolation (PVI) is based on contiguous (≤6 mm) and optimized radiofrequency (RF) ablation lesions (ablation index [AI] ≥ 400 posteriorly and ≥ 550 anteriorly]. However, the optimal RF power to reach the desired AI is unknown. Therefore we evaluated the efficiency of an ablation strategy using higher power (40 W) during a first "CLOSE"-guided PVI. METHODS: Eighty consecutive patients undergoing "CLOSE"-guided PVI for symptomatic paroxysmal atrial fibrillation were ablated with 40 W (group A). Results were compared with 105 consecutive patients enrolled in the "CLOSE to CURE"-study and were ablated using the same protocol with 35 W (group B). RESULTS: In group A, ablation was associated with shorter ablation procedure time (91 vs 111 minutes; P < .001), shorter fluoroscopy time (5 vs 11 minutes; P < .001), shorter PVI time (48 vs 64 minutes; P < .001), shorter RF time (20 vs 28 minutes; P < .001), lower RF time per application (22 vs 29 seconds; P < .001), less RF applications (52 vs 58; P < .001), and less catheter dislocations (1 vs 2; P = .002). The impedance drop (12 vs 13 Ω; P = .192), first-pass isolation rate (99% vs 93%; P = .141) and acute reconnection rate (6% vs 4%; P > .733) were similar in both groups (groups A and B, respectively). No complications occurred. In group A, a gastroscopy-performed in five patients with esophageal temperature rise more than 42°C-did not reveal any esophageal lesion. Postprocedural recurrence of atrial tachyarrhythmia at 1 year was not significantly different between both groups. CONCLUSIONS: Using the "CLOSE"-protocol, increased power increases the efficiency of PVI without compromising patients' safety.

Utility of electrophysiological studies to predict arrhythmic events.

AIM: To evaluate the prognostic value of electrophysiological stimulation (EPS) in the risk stratification for tachyarrhythmic events and sudden cardiac death (SCD). METHODS: We conducted a prospective cohort study and analyzed the long-term follow-up of 265 consecutive patients who underwent programmed ventricular stimulation at the Luzerner Kantonsspital (Lucerne, Switzerland) between October 2003 and April 2012. Patients underwent EPS for SCD risk evaluation because of structural or functional heart disease and/or electrical conduction abnormality and/or after syncope/cardiac arrest. EPS was considered abnormal, if a sustained ventricular tachycardia (VT) was inducible. The primary endpoint of the study was SCD or, in implanted patients, adequate ICD-activation. RESULTS: During EPS, sustained VT was induced in 125 patients (47.2%) and non-sustained VT in 60 patients (22.6%); in 80 patients (30.2%) no arrhythmia could be induced. In our cohort, 153 patients (57.7%) underwent ICD implantation after the EPS. During follow-up (mean duration 4.8 ± 2.3 years), a primary endpoint event occurred in 49 patients (18.5%). The area under the receiver operating characteristic curve (AUROC) was 0.593 (95%CI: 0.515-0.670) for a left ventricular ejection fraction (LVEF) < 35% and 0.636 (95%CI: 0.563-0.709) for inducible sustained VT during EPS. The AUROC of EPS was higher in the subgroup of patients with LVEF ≥ 35% (0.681, 95%CI: 0.578-0.785). Cox regression analysis showed that both, sustained VT during EPS (HR: 2.26, 95%CI: 1.22-4.19, P = 0.009) and LVEF < 35% (HR: 2.00, 95%CI: 1.13-3.54, P = 0.018) were independent predictors of primary endpoint events. CONCLUSION: EPS provides a benefit in risk stratification for future tachyarrhythmic events and SCD and should especially be considered in patients with LVEF ≥ 35%.

Hospital-integrated general practice: a promising way to manage walk-in patients in emergency departments.

RATIONALE, AIMS AND OBJECTIVES: The inappropriate use and overcrowding of emergency departments (EDs) by walk-in patients are well-known problems in many countries. The current study aimed to determine whether ambulatory walk-in patients could be treated more efficiently in a new hospital-integrated general practice (HGP) for emergency care services compared to a traditional ED. METHODS: We conducted a pre-post comparison before and after the implementation of a new HGP. Participants were walk-in patients attending the ED of a city hospital in Zurich. Main outcome measures were differences in total process time, time intervals between stages of care and diagnostic resources used. RESULTS: The median process time from admission to discharge was 120 minutes in the ED [interquartile range (IQR): 80-165] versus 60 minutes in the HGP (IQR: 40-90) (P < 0.001). The adjusted odds ratio of receiving any additional diagnostics was 1.86 (95% confidence interval 1.06-3.27; P = 0.032) for ED doctors versus general practitioners (GPs) when controlling for patients' age, sex and injury-related medical problems. CONCLUSION: The HGP is an efficient way to manage walk-in patients with regard to process time and utilization of additional diagnostic resources. The involvement of GPs in the HGPs should be considered as a promising model to overcome the inappropriate use of resources in EDs for walk-in patients who can be treated by ambulatory care.