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

BACKGROUND

Visually guided laser balloon ablation is known as an effective pulmonary vein (PV) isolation device. The third-generation laser balloon ablation system (X3) equipped with compliant balloon and an automated motor-driven laser output mechanism, namely RAPID mode, has been clinically proven for PV isolation.

METHODS

PV isolation with X3 was performed in all the patients with paroxysmal and early-stage persistent atrial fibrillation (AF). Acute data for PV isolation and clinical outcomes including supraventricular tachyarrhythmia (SVT: AF, atrial flutter, or atrial tachycardia)-free survival rate beyond 1 year were analyzed.

RESULTS

A total of 110 patients (62 ± 13 years old, 80% of paroxysmal AF) were treated with X3. RAPID mode with was utilized to achieve PV isolation in all cases. In combination with RAPID mode and spot mode laser ablation, 91.1% (380/417) of veins were isolated on the first circumferential lesion set and did not require touch-up ablation and during the index procedure 100% of attempted veins were isolated. The mean procedure time was 77.0 ± 22.7 min and LA dwell time was 61.9 ± 22.0 min. Total duration of laser application was 5.1 ± 2.3 min per vein. At 1 year, SVT-free survival rate was 93.7% in paroxysmal AF patients, and 81.1% in persistent AF patients.

CONCLUSIONS

A novel continuous automatic laser balloon ablation system was proved to be safe and effective for both paroxysmal and persistent AF patients. The clinical result demonstrated that PV isolation with X3 could achieve a high SVT-free survival rate.

Cardiac Arrest as an Uncommon Manifestation of Late Type A Aortic Dissection Associated with Transcatheter Aortic Valve Replacement

Transcatheter aortic valve replacement (TAVR) is a minimally invasive therapeutic procedure with a consistent, linear increase in the number of implantations worldwide. Recently, TAVR has been rapidly expanding into lower-risk populations. Sporadic cases of late prosthesis-related Stanford type A dissection have been documented in self-expanding, as well as balloon-expandable TAVR valves, manifested primarily as acute aortic syndrome. We present the case of a 76-year-old male, who experienced refractory in-hospital cardiac arrest with non-shockable rhythm due to the obstruction of coronary flow caused by aortic dissection type A, with entry directly adjacent to the aortic prosthesis according to autopsy. The patient died despite the engagement of extracorporeal cardiopulmonary resuscitation. Aortic dissection developed one year after a transfemoral TAVR procedure using an Edwards SAPIEN 3 29 mm self-expanding valve. TAVR-associated late aortic dissection type A represents a rare, life-threatening condition with various clinical manifestations. The risk factors have not been well described and the differential diagnosis may be challenging. As the number of TAVR recipients and their life expectancy is increasing, we may face this complication more often in future.

Extracorporeal Membrane Oxygenation in the Therapy of Cardiogenic Shock: Results of the ECMO-CS Randomized Clinical Trial

BACKGROUND

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly being used for circulatory support in patients with cardiogenic shock, although the evidence supporting its use in this context remains insufficient. The ECMO-CS trial (Extracorporeal Membrane Oxygenation in the Therapy of Cardiogenic Shock) aimed to compare immediate implementation of VA-ECMO versus an initially conservative therapy (allowing downstream use of VA-ECMO) in patients with rapidly deteriorating or severe cardiogenic shock.

METHODS

This multicenter, randomized, investigator-initiated, academic clinical trial included patients with either rapidly deteriorating or severe cardiogenic shock. Patients were randomly assigned to immediate VA-ECMO or no immediate VA-ECMO. Other diagnostic and therapeutic procedures were performed as per current standards of care. In the early conservative group, VA-ECMO could be used downstream in case of worsening hemodynamic status. The primary end point was the composite of death from any cause, resuscitated circulatory arrest, and implementation of another mechanical circulatory support device at 30 days.

RESULTS

A total of 122 patients were randomized; after excluding 5 patients because of the absence of informed consent, 117 subjects were included in the analysis, of whom 58 were randomized to immediate VA-ECMO and 59 to no immediate VA-ECMO. The composite primary end point occurred in 37 (63.8%) and 42 (71.2%) patients in the immediate VA-ECMO and the no early VA-ECMO groups, respectively (hazard ratio, 0.72 [95% CI, 0.46-1.12]; P=0.21). VA-ECMO was used in 23 (39%) of no early VA-ECMO patients. The 30-day incidence of resuscitated cardiac arrest (10.3.% versus 13.6%; risk difference, -3.2 [95% CI, -15.0 to 8.5]), all-cause mortality (50.0% versus 47.5%; risk difference, 2.5 [95% CI, -15.6 to 20.7]), serious adverse events (60.3% versus 61.0%; risk difference, -0.7 [95% CI, -18.4 to 17.0]), sepsis, pneumonia, stroke, leg ischemia, and bleeding was not statistically different between the immediate VA-ECMO and the no immediate VA-ECMO groups.

CONCLUSIONS

Immediate implementation of VA-ECMO in patients with rapidly deteriorating or severe cardiogenic shock did not improve clinical outcomes compared with an early conservative strategy that permitted downstream use of VA-ECMO in case of worsening hemodynamic status.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02301819.

Acute Severe Heart Failure Reduces Heart Rate Variability: An Experimental Study in a Porcine Model

There are substantial differences in autonomic nervous system activation among heart (cardiac) failure (CF) patients. The effect of acute CF on autonomic function has not been well explored. The aim of our study was to assess the effect of experimental acute CF on heart rate variability (HRV). Twenty-four female pigs with a mean body weight of 45 kg were used. Acute severe CF was induced by global myocardial hypoxia. In each subject, two 5-min electrocardiogram segments were analyzed and compared: before the induction of myocardial hypoxia and >60 min after the development of severe CF. HRV was assessed by time-domain, frequency-domain and nonlinear analytic methods. The induction of acute CF led to a significant decrease in cardiac output, left ventricular ejection fraction and an increase in heart rate. The development of acute CF was associated with a significant reduction in the standard deviation of intervals between normal beats (50.8 [20.5−88.1] ms versus 5.9 [2.4−11.7] ms, p < 0.001). Uniform HRV reduction was also observed in other time-domain and major nonlinear analytic methods. Similarly, frequency-domain HRV parameters were significantly changed. Acute severe CF induced by global myocardial hypoxia is associated with a significant reduction in HRV.

Coronary Arterial Spasm During Pulsed Field Ablation to Treat Atrial Fibrillation

BACKGROUND

Pulsed field ablation (PFA) has a unique safety profile when used to treat atrial fibrillation, largely related to its preferentiality for myocardial tissue ablation, in particular, esophageal sparing. A pentaspline catheter was the first such PFA system studied clinically for atrial fibrillation ablation; in these initial regulatory trials, the catheter was used for pulmonary vein isolation and left atrial posterior wall ablation. Since its regulatory approval in Europe, in clinical practice, physicians have ablated beyond pulmonary vein isolation and left atrial posterior wall ablation to expanded lesion sets in closer proximity to coronary arteries. This is an unstudied important issue because preclinical and clinical data have raised the potential for coronary arterial spasm. Herein, we studied the vasospastic potential of PFA lesion sets, both remote from and adjacent to coronary arteries.

METHODS

During routine atrial fibrillation ablation using the pentaspline PFA catheter, coronary angiography was performed before, during, and after pulsed field applications. The lesion sets studied included: (1) those remote from the coronary arteries such as pulmonary vein isolation (n=25 patients) and left atrial posterior wall ablation (n=5), and (2) ablation of the cavotricuspid isthmus (n=20) that is situated adjacent to the right coronary artery.

RESULTS

During pulmonary vein isolation and left atrial posterior wall ablation, coronary spasm did not occur, but cavotricuspid isthmus ablation provoked severe subtotal vasospasm in 5 of 5 (100%) consecutive patients, and this was relieved by intracoronary nitroglycerin in 5.5±3.5 minutes. ST-segment elevation was not observed. However, no patient (0%, P=0.004) had severe spasm if first administered parenteral nitroglycerin, either intracoronary (n=5) or intravenous (n=10), before treatment.

CONCLUSIONS

Coronary vasospasm was not provoked during PFA at locations remote from coronary arteries, but when the energy is delivered adjacent to a coronary artery, PFA routinely provokes subclinical vasospasm. This phenomenon is attenuated by nitroglycerin, administered either post hoc to treat spasm or as prophylaxis.

A Total of 207 Days of Veno-Venous Extracorporeal Membrane Oxygenation Support for Severe COVID-19 Prior to Successful Lung Transplantation: A Case Report

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is a life-saving treatment for respiratory failure that may serve as a bridge to patient recovery or lung transplantation. In COVID-19, recovery is somewhat unpredictable and occasionally occurs after >100 days on VV-ECMO support. Thus, determining therapy cessation may be difficult. We report the case of a 59-year-old male without specific risk factors admitted to a tertiary center for rapidly progressive respiratory failure due to severe COVID-19, despite aggressive mechanical ventilatory support. Immediate insertion of VV-ECMO was associated with prompt resolution of hypoxemia and hypercapnia; however, all therapeutic efforts to wean the patient from VV-ECMO failed. During the prolonged hospitalization on VV-ECMO, sepsis was the most life-threatening complication. The patient overcame roughly 40 superinfections, predominantly affecting the respiratory tract, and spent 183 days on antimicrobial treatment. Although the function of other organ systems was generally stable, gradually progressive right ventricular dysfunction due to precapillary pulmonary hypertension required increasing doses of inotropes. A successful lung transplantation was performed after 207 days of VV-ECMO support. The present case provides evidence for prolonged VV-ECMO therapy as a bridge to lung transplantation in severe COVID-19 despite numerous, predominantly infectious complications.

Aortic stenosis and mitral regurgitation modify the effect of venoarterial extracorporeal membrane oxygenation on left ventricular function in cardiogenic shock

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is widely used in the treatment of patients experiencing cardiogenic shock (CS). However, increased VA-ECMO blood flow (EBF) may significantly impair left ventricular (LV) performance. The objective of the present study was to assess the effect of VA-ECMO on LV function in acute CS with concomitant severe aortic stenosis (AS) or mitral regurgitation (MR) in a porcine model. Eight female swine (45 kg) underwent VA-ECMO implantation under general anaesthesia and mechanical ventilation. Acute CS was induced by global myocardial hypoxia. Subsequently, severe AS was simulated by obstruction of the aortic valve, while severe MR was induced by mechanical destruction of the mitral valve. Haemodynamic and LV performance variables were measured at different rates of EBF rates (ranging from 1 to 4 L/min), using arterial and venous catheters, a pulmonary artery catheter, and LV pressure-volume catheter. Data are expressed as median (interquartile range). Myocardial hypoxia resulted in declines in cardiac output to 2.7 (1.9-3.1) L/min and LV ejection fraction to 15.2% (10.5-19.3%). In severe AS, increasing EBF from 1 to 4 L/min was associated with a significant elevation in mean arterial pressure (MAP), from 33.5 (24.2-34.9) to 56.0 (51.9-73.3) mmHg (P ˂ 0.01). However, LV volumes (end-diastolic, end-systolic, stroke) remained unchanged, and LV end-diastolic pressure (LVEDP) significantly decreased from 24.9 (21.2-40.0) to 19.1 (15.2-29.0) mmHg (P ˂ 0.01). In severe MR, increasing EBF resulted in a significant elevation in MAP from 49.0 (28.0-53.4) to 72.5 (51.4-77.1) mmHg (P ˂ 0.01); LV volumes remained stable and LVEDP increased from 17.1 (13.7-19.1) to 20.8 (16.3-25.6) mmHg (P ˂ 0.01). Results of this study indicate that the presence of valvular heart disease may alleviate negative effect of VA-ECMO on LV performance in CS. Severe AS fully protected against LV overload, and partial protection was also detected with severe MR, although at the cost of increased LVEDP and, thus, higher risk for pulmonary oedema.

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

INTRODUCTION

When cardiac magnetic resonance (MR) is performed after previous leadless transcatheter pacemaker implantation, an image distortion has to be expected in the heart region and evaluation of myocardial tissue can be affected. In this clinical prospective study, we aim to assess the extent and impact of this artifact on individual ventricular segments and compare it to conventional pacing devices.

METHODS

Total of 20 patients with leadless pacemaker placed in the right ventricle underwent cardiac MR imaging in a 1.5 Tesla scanner. A multiplanar segmentation was used to demarcate the left and right ventricular myocardium as well as the pacemaker-caused image artifact in systolic and diastolic time frames. Artifact size and its relative influence on myocardial segments were quantitatively assessed and expressed in AHA-17 model.

RESULTS

Implanted leadless pacemaker caused an image artifact with a volume of 48 ± 5 ml. Most distorted were the apical septal (53 ± 23%), apical inferior (30 ± 18%), and midventricular inferoseptal (30 ± 20%) segments. The artifact intersection with basal and lateral segments was none or negligible (up to 2%). The portion of left ventricular (LV) myocardium affected by the artifact was significantly higher in systole (8 ± 4%) compared to diastole (10 ± 3%; p < .001).

CONCLUSION

Implantation of leadless pacemaker represents no obstacle for cardiac MR imaging but causes an image artifact located mostly in septal, inferoseptal, and anteroseptal segments of apical and midventricular LV myocardium. With the exception of the apex, diastolic timing reduces the image distortion of all segments and improves global ventricular assessment.

Successful Retrieval of a 4-Year-Old Micra Transcatheter Pacemaker System in a Patient With Leadless Biventricular Pacing Therapy

This is the first report of the management of a patient with cardiac resynchronization therapy using leadless biventricular pacing. Successful retrieval of a 4-year-old Micra transcatheter pacing system (TPS) and reimplantation of a new Micra TPS prevented device-to-device interactions from multiple pacing devices in the right ventricle. (Level of Difficulty: Advanced.).

Refractory cardiac arrrest treated with extracorporeal cardiopulmonary resuscitation, 2-year follow-up

Introduction

Extracorporeal cardiopulmonary resuscitation (ECPR) has been introduced as a life-saving procedure in refractory cardiac arrest.

Methods

Eligible patients for this analysis had to undergo ECPR after unsuccessful cardiopulmonary resuscitation with a minimum of three defibrillation attempts. For extracorporeal life support (ECLS) was used Cardiohelp system or Levitronix CentriMag blood pump. LUCAS II system was used for chest compressions during cardiac arrest. The relations of blood lactate and pH levels, measured before ECPR insertion and after 24 hours as well as comorbities (diabetes, hypertension, BMI) to the clinical outcomes at 2 years were evaluated.

Results

We analyzed data from 59 patients treated with ECPR for refractory cardiac arrest. The mean age of our patients was 61 years. Out-of-hospital cardiac arrest (OHCA) occurred in 33 patients, 26 patients suffered from in-hospital arrest (IHCA). Baseline value of lactate was 11.57±4.22 mmol/l, initial pH 6.95±0.31. In comparison with survivors, patients who died had significantly higher initial lactate levels (12.05±0.81 vs. 8.01±0.77; P&lt;0.05). Moreover, survivors had significantly lower lactate levels after 24 hours (7.39 vs 2.56) and lower BMI (27.4 vs 31.2; P&lt;0.05). Diabetes or hypertension in our group have no influence on the mortality. The difference of mortality in the group of OHCA or IHCA was also not significant. 32% patients survived one month with good neurological outcome (CPC 1–2), 30% six months, 23% one year and 21% two years.

Conclusions

ECPR give the last chance to survive refractory cardiac arrest. The levels of blood lactate are significantly associated with clinical outcomes of ECPR. Obesity was associated with significantly higher mortality in our group.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): MH CZ DRO (Nemocnice Na Homolce - NNH, 00023884)

Continual measurement of arterial dP/dtmax enables minimally invasive monitoring of left ventricular contractility in patients with acute heart failure

Background

Continuous, reliable evaluation of left ventricular (LV) contractile function in patients with advanced heart failure requiring intensive care remains challenging. Continual monitoring of dP/dt_max from the arterial line has recently become available in hemodynamic monitoring. However, the relationship between arterial dP/dt_max and LV dP/dt_max remains unclear. This study aimed to determine the relationship between arterial dP/dt_max and LV dP/dt_max assessed using echocardiography in patients with acute heart failure.

Methods

Forty-eight patients (mean age 70.4 years [65% male]) with acute heart failure requiring intensive care and hemodynamic monitoring were recruited. Hemodynamic variables, including arterial dP/dt_max, were continually monitored using arterial line pressure waveform analysis. LV dP/dt_max was assessed using continuous-wave Doppler analysis of mitral regurgitation flow.

Results

Values from continual arterial dP/dt_max monitoring were significantly correlated with LV dP/dt_max assessed using echocardiography (r = 0.70 [95% confidence interval (CI) 0.51–0.82]; P < 0.0001). Linear regression analysis revealed that LV dP/dt_max = 1.25 × (arterial dP/dt_max) (P < 0.0001). Arterial dP/dt_max was also significantly correlated with stroke volume (SV) (r = 0.63; P < 0.0001) and cardiac output (CO) (r = 0.42; P = 0.0289). In contrast, arterial dP/dt_max was not correlated with SV variation, dynamic arterial elastance, heart rate, systemic vascular resistance (SVR), or mean arterial pressure. Markedly stronger agreement between arterial and LV dP/dt_max was observed in subgroups with higher SVR (N = 28; r = 0.91; P <  0.0001), lower CO (N = 26; r = 0.81; P <  0.0001), and lower SV (N = 25; r = 0.60; P = 0.0014). A weak correlation was observed in the subjects with lower SVR (N = 20; r = 0.61; P = 0.0004); in the subgroups with higher CO (N = 22) and higher SV (N = 23), no significant correlation was found.

Conclusion

Our results suggest that in patients with acute heart failure requiring intensive care with an arterial line, continuous calculation of arterial dP/dt_max may be used for monitoring LV contractility, especially in those with higher SVR, lower CO, and lower SV, such as in patients experiencing cardiogenic shock. On the other hand, there was only a weak or no significant correlation in the subgroups with higher CO, higher SV, and lower SVR.

P998Left atrial appendage closure device thrombosis is associated with systemic embolization

Introduction

Atrial fibrillation, in one of its forms, is the most frequent sustained tachyarrhythmia and increases the risk of stroke more than 5 times. Cardioembolic stroke and systemic embolism (CS/SE) represents the most severe complication of this arrhythmia. Approximately 92% of intracardiac thrombosis originates from the left atrial appendage (LAA) and, although its mechanical occlusion is proved method to prevent cardioembolism, thrombosis of all types of LAA occlusion devices and their associations with CS/SE were observed.

The purpose of this study is to evaluate the rate of LAA occlusion device thrombosis, its predictors and the risk for cardioembolism.

Methods

We analyzed a group of 359 patients (65% male, mean age 72 years) with high risk for thromboembolism (mean CHADSVASc = 4.0) after LAA catheter occlusion using any of 9 different occluder types since 2005. During clinical follow-up 819 patientyears were collected and an intracardiac thrombus was found on 22 devices. Total of 17 patients suffered CS/SE.

Results

Thrombosis was found in 11 men and 11 women, mean age 76 years, average CHADSVASc = 4.5 and HASBLED = 2.0. The thrombus was discovered on average 4.0 months after the LAA occlusion. In that time patients were receiving dual antiplatelet therapy (11x), acetysalicic acid (4x), or interrupted anticoagulation (6x). In 3 cases the thrombosis was associated with CS/SE which represented risk of 6.6% per year. In patients with no thrombosis annual risk of CS/SE was only 1.7% (P<0.001).

Figure 1

Conclusion

In our single center register thrombosis was found in total of 6.3% patients after LAA device implantation. In these patients, risk of CS/SE is 3.9-fold higher compared to patients without thrombus formation. Elderly patients and patients with more risk factors in general were affected more frequently.

Association of neuron-specific enolase values with outcomes in cardiac arrest survivors is dependent on the time of sample collection

Background

Despite marked advances in intensive cardiology care, current options for outcome prediction in cardiac arrest survivors remain significantly limited. The aim of our study was, therefore, to compare the day-specific association of neuron-specific enolase (NSE) with outcomes in out-of-hospital cardiac arrest (OHCA) survivors treated with hypothermia.

Methods

Eligible patients were OHCA survivors treated with targeted temperature management at 33 °C for 24 h using an endovascular device. Blood samples for NSE levels measurement were drawn on days 1, 2, 3, and 4 after hospital admission. Thirty-day neurological outcomes according to the Cerebral Performance Category (CPC) scale and 12-month mortality were evaluated as clinical end points.

Results

A total of 153 cardiac arrest survivors (mean age 64.2 years) were enrolled in the present study. Using ROC analysis, optimal cutoff values of NSE for prediction of CPC 3–5 score on specific days were determined as: day 1 > 20.4 mcg/L (sensitivity 63.3%; specificity 82.1%; P = 0.002); day 2 > 29.0 mcg/L (72.5%; 94.4%; P < 0.001); and day 3 > 20.7 mcg/L (94.4%; 86.7%; P < 0.001). The highest predictive value, however, was observed on day 4 > 19.4 mcg/L (93.5%; 91.0%; P < 0.001); NSE value >50.2 mcg/L at day 4 was associated with poor outcome with 100% specificity and 42% sensitivity. Moreover, NSE levels measured on all individual days also predicted 12-month mortality (P < 0.001); the highest predictive value for death was observed on day 3 > 18.1 mcg/L (85.3%; 72.0%; P < 0.001). Significant association with prognosis was found also for changes in NSE at different time points. An NSE level on day 4 > 20.0 mcg/L, together with a change > 0.0 mcg/L from day 3 to day 4, predicted poor outcome (CPC 3–5) with 100% specificity and 73% sensitivity.

Conclusions

Our results suggest that NSE levels are a useful tool for predicting 30-day neurological outcome and long-term mortality in OHCA survivors treated with targeted temperature management at 33 °C. The highest associations of NSE with outcomes were observed on day 4 and day 3 after cardiac arrest.

Left Atrial Appendage Closure Under Intracardiac Echocardiographic Guidance: Feasibility and Comparison With Transesophageal Echocardiography

Background

Transcatheter left atrial appendage closure is an alternative therapy for stroke prevention in atrial fibrillation patients. These procedures are currently guided with transesophageal echocardiography and fluoroscopy in most centers. As intracardiac echocardiography (ICE) is commonly used in other catheter‐based procedures, we sought to determine the safety and effectiveness of intracardiac echocardiography–guided left atrial appendage closure with the Watchman device.

Methods and Results

A total of 27 patients (11 males, 77.0±8.5 years) with atrial fibrillation receiving Watchman left atrial appendage closure under intracardiac echocardiography guidance at a single center were investigated. All patients were implanted successfully. There were no major procedural complications. The overall procedure‐related complication rate was 14.8%, mainly due to access site hematoma. Transesophageal echocardiography demonstrated successful closure of the left atrial appendage in all patients at 45 days after device implant.

Conclusions

Transcatheter left atrial appendage closure with intracardiac echocardiography guidance is safe and feasible.

Anatomical predictors for successful pulmonary vein isolation using balloon-based technologies in atrial fibrillation

PURPOSE

We evaluated the correlation between pulmonary venous (PV) anatomy and acute and long-term success of PV isolation (PVI) with two balloon-based ablation catheter techniques.

METHODS

One hundred consecutive patients were analyzed in two equal groups treated with either the second-generation cryoballoon (CRYO) catheter or the visually guided laser ablation (VGLA) catheter. All patients underwent multi-detector computed tomography (CT) imaging. The primary and secondary efficacy endpoints were the procedural achievement of proven electrical isolation of all veins and freedom from atrial fibrillation (AF) within a 1-year follow-up period, respectively.

RESULTS

Variant PV anatomy was observed in 32% of patients in the CRYO group and in 40% of patients in the VGLA group. All PVs were targeted with either the CRYO catheter (n = 199) or the VGLA catheter (n = 206). One hundred ninety-three of 199 PVs (97%) were successfully isolated in the CRYO group and 194 of 206 PVs (94%) in the VGLA group (p = 0.83). Over a 12-month follow-up, AF recurrence was documented in 11/45 (24%) and 7/43 (16%) patients in the CRYO and the VGLA groups, respectively (p = 0.21). In the CRYO group, a larger left inferior PV size was associated with worse long-term outcome (p = 0.001). In the VGLA group, a larger left superior PV size (p = 0.003) and more oval right inferior PV were associated with worse acute success (p = 0.038). There was no absolute cutoff between PV anatomy and clinical success.

CONCLUSIONS

The variability of PV anatomy did not significantly compromise acute success of PVI or patient outcomes.

Ischemic Postconditioning and Nitric Oxide Administration Failed to Confer Protective Effects in a Porcine Model of Extracorporeal Cardiopulmonary Resuscitation

The protective effects of ischemic postconditioning (IPC) and nitric oxide (NO) administration have been demonstrated in several ischemic scenarios. However, current evidence regarding the effect of IPC and NO in extracorporeal cardiopulmonary resuscitation remains lacking. Fifteen female swine (body weight 45 kg) underwent veno-arterial extracorporeal membrane oxygenation (ECMO) implantation; cardiac arrest-ventricular fibrillation was induced by rapid ventricular pacing. After 20 min of cardiac arrest, blood flow was restored by increasing the ECMO flow rate to 4.5 L/min. The animals (five per group) were then randomly assigned to receive IPC (three cycles of 3 min ischemia and reperfusion), NO (80 ppm via oxygenator), or mild hypothermia (HT; 33.0°C). Cerebral oximetry and aortic blood pressure were monitored continuously. After 90 min of reperfusion, blood samples were drawn for the measurement of troponin I, myoglobin, creatine-phosphokinase, alanine aminotransferase, neuron-specific enolase, cystatin C, and reactive oxygen metabolite (ROM) levels. Significantly higher blood pressure and cerebral oxygen saturation values were observed in the HT group compared with the IPC and NO groups (P < 0.05). The levels of troponin I, myoglobin, creatine phosphokinase, and alanine aminotransferase were significantly lower in the HT group (P < 0.05); levels of neuron-specific enolase, cystatin C, and ROM were not significantly different. IPC and NO were comparable in all monitored parameters. The results of the present study indicate that IPC and NO administration are not superior interventions to HT for the maintenance of blood pressure, cerebral oxygenation, organ protection, and suppression of oxidative stress following extracorporeal cardiopulmonary resuscitation.

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

Background

The aim of this study was to assess the relationship between extracorporeal blood flow (EBF) and left ventricular (LV) performance during venoarterial extracorporeal membrane oxygenation (VA ECMO) therapy.

Methods

Five swine (body weight 45 kg) underwent VA ECMO implantation under general anesthesia and artificial ventilation. Subsequently, acute cardiogenic shock with signs of tissue hypoxia was induced. Hemodynamic and cardiac performance parameters were then measured at different levels of EBF (ranging from 1 to 5 L/min) using arterial and venous catheters, a pulmonary artery catheter and a pressure–volume loop catheter introduced into the left ventricle.

Results

Myocardial hypoxia resulted in a decline in mean (±SEM) cardiac output to 2.8 ± 0.3 L/min and systolic blood pressure (SBP) to 60 ± 7 mmHg. With an increase in EBF from 1 to 5 L/min, SBP increased to 97 ± 8 mmHg (P < 0.001); however, increasing EBF from 1 to 5 L/min significantly negatively influences several cardiac performance parameters: cardiac output decreased form 2.8 ± 0.3 L/min to 1.86 ± 0.53 L/min (P < 0.001), LV end-systolic volume increased from 64 ± 11 mL to 83 ± 14 mL (P < 0.001), LV stroke volume decreased from 48 ± 9 mL to 40 ± 8 mL (P = 0.045), LV ejection fraction decreased from 43 ± 3 % to 32 ± 3 % (P < 0.001) and stroke work increased from 2096 ± 342 mmHg mL to 3031 ± 404 mmHg mL (P < 0.001). LV end-diastolic pressure and volume were not significantly affected.

Conclusions

The results of the present study indicate that higher levels of VA ECMO blood flow in cardiogenic shock may negatively affect LV function. Therefore, it appears that to mitigate negative effects on LV function, optimal VA ECMO blood flow should be set as low as possible to allow adequate tissue perfusion.

Magnetic resonance imaging in patients with a subcutaneous implantable cardioverter-defibrillator

Aims

Our aim was to evaluate the potential for safely imaging patients with a new type of implantable cardioverter-defibrillator called the subcutaneous implantable cardioverter-defibrillator (S-ICD) in a 1.5 T magnetic resonance imaging (MRI) scanner. With the increasing number of patients with cardiac implantable devices who are indicated for MRI, there is a growing need for establishing MRI compatibility of cardiac implantable devices.

Methods and Results

Patients with implanted S-ICD systems underwent one or more types of anatomical MRI scans. The S-ICD was programmed off and patients were monitored throughout the imaging procedure. Device function was evaluated pre- and post-scan. Patients were asked to report immediately any pain, torqueing movement, or heating sensation in the area of the pocket or electrode. Fifteen patients underwent a total of 22 examinations at 1.5 T. Scans included brain, spine, knee, and heart. Two patients were re-scanned due to complaints of heating over the can during lumbar scans, which was caused by a thermistor probe placed on the skin to measure skin temperature. All the remaining scans occurred without incident. No evidence of device malfunction was observed.

Conclusion

This study is the first to domonstrate the feasibility of exposing S-ICD patients to MRI using the scanning and monitoring protocol described. More data are required to support S-ICD as a MRI conditional device.

Visually guided laser ablation: a single-centre long-term experience

AIMS

Durable isolation of the pulmonary veins (PVs) remains the cornerstone of treatment for paroxysmal atrial fibrillation (PAF) and is also used in the treatment of some patients with persistent atrial fibrillation. Visually guided laser ablation (VGLA) has been proven to be safe and effective as a treatment for atrial fibrillation (AF). It has shown high levels of durable PV isolation (PVI), even in the hands of less experienced users. This paper presents the long-term clinical outcomes of all patients treated with VGLA over the course of 4 years in the world's most experienced centre: from early product feasibility work treating only PAF patients to our work using the commercially available product, when we also treated persistent AF patients.

METHODS AND RESULTS

One hundred and ninety-four patients (63 females, mean age 61 years) with either a history of drug-refractory PAF (time since initial diagnosis: 60.73 months) or persistent AF (time since initial diagnosis: 62.75 months) were treated in our laboratory with VGLA between 7 January 2009 and 17 May 2013. Follow-up of all patients was consistent with our standard clinical practice with a 7-day Holter being performed at the first clinical visit between 4 and 6 months and, for most patients, again at 12 months post-procedure. Twelve lead electrocardiograms were performed at all clinical visits. Recurrence of AF is defined as any documented AF episode >30 s. Acute procedural results show that 692 veins were acutely isolated with a mean procedure and fluoroscopy time of 226 and 20.4 min, respectively. One hundred and seventy (158 PAF and 12 persistent AF) patients reached 1 year of follow-up, 130 (82.3%) patients remained free of AF in the PAF group, and 9 (75%) in the persistent group. Eighty-seven PAF patients have now reached 24 months follow-up and 66 (75.9%) remain free of AF. Fifty-four PAF patients have reached 36 months follow-up with 41 (75.9%) remaining free of AF. Thirty-two PAF patients have reached 48 months follow-up and 24 (75%) remain free of AF. The peri-procedural complications we encountered were phrenic nerve injury in four patients (2.06%), tamponade or pericardial effusion in one patient (0.51%), stroke or transient ischaemic attack in one patient (0.514%), and vascular injury in six patients (3.09%). We experienced no cases of PV stenosis or atrio-oesophageal fistula.

CONCLUSION

Our single-centre experience using VGLA over 4 years shows that it can be used safely and effectively in normal clinical practice and gives high levels of acute PVI accompanied by good clinical outcomes, even after long-term follow-up.

Noninvasive assessment of hemodynamic variables using near-infrared spectroscopy in patients experiencing cardiogenic shock and individuals undergoing venoarterial extracorporeal membrane oxygenation

PURPOSE

The relationship between near-infrared spectroscopy cerebral oximetry (CrSO2), peripheral oximetry (PrSO2) and hemodynamic variables is not fully understood.

METHODS

The relationship between CrSO2/PrSO2 and cardiac index (CI), systemic vascular resistance index (SVRI) and mean arterial pressure (MAP) in patients experiencing cardiogenic shock and those undergoing venoarterial extracorporeal membrane oxygenation (ECMO) was retrospectively analyzed; in patients on ECMO, total circulatory index (TCI) was calculated from the sum of CI and extracorporeal blood flow index.

RESULTS

In patients experiencing cardiogenic shock (n=10), significant correlations between PrSO2 values and CI (Spearman r=0.81; P<.0001), SVRI (r=-0.45; P<.0001), and MAP (r=0.58; P<.0001) were found. Significant correlations between CrSO2 and CI (r=0.55; P<.0001) and SVRI (r=-0.47; P<.0001), but not MAP, were observed. Linear regression analysis revealed that CI could be calculated using the following equation: CI=PrSO2/24.0. In patients on VA ECMO (n=12), significant correlations were found between PrSO2 and TCI (r=0.68; P<.0001), SVRI (r=-0.47; P<.0001), and MAP (r=0.27; P=.025). Significant correlations were also found between CrSO2 and TCI (r=0.68; P<.0001) and SVRI (r=-0.51; P<.0001), but not MAP.

CONCLUSIONS

Results of the present study suggest that CrSO2 and PrSO2 in particular can be used for noninvasive estimation and monitoring of global circulatory status in patients experiencing cardiogenic shock and individuals undergoing ECMO.

Alteration in lipoprotein-associated phospholipase A2 levels during acute coronary syndrome and its relationship to standard biomarkers

BACKGROUND

Lipoprotein-associated phospholipase A2 (Lp-PLA2) probably plays an important role in the development of acute coronary syndrome (ACS); elevated levels of Lp-PLA2 are associated with a poorer prognosis in patients with ischemic heart disease. Alterations of Lp-PLA2 levels during ACS and its relationship to standard biomarkers are, however, unclear.

FINDINGS

Fifty-one consecutive ACS patients were enrolled in the study. All were managed with early invasive strategy and according to the current guidelines for pharmacotherapy; intensive statin therapy was started in all patients at admission. Serum levels of Lp-PLA2, LDL-cholesterol (LDL), troponin l (Tnl), and C-reactive protein (CRP) were assessed at admission (D0), on the first morning (D1), and on the second morning of hospitalization (D2). Mean serum levels of Lp-PLA2 (ng/mL) decreased from 264.6±19.1 at D0, to 193.2±14.4 at D1 (P < 0.001 vs. D0) and 189.8±22.6 at D2 (P = 0.002 vs. D0; P = not significant vs. D1). Alterations in Lp-PLA2 levels significantly correlated with changes in LDL (r = 0.43; P = 0.008). On the other hand, no relationship between Lp-PLA2 and Tnl or CRP was found.

CONCLUSIONS

Initially, serum levels of Lp-PLA2 were significantly elevated in ACS patients, but decreased within the first 24 hours after admission and subsequently remained stable. Lp-PLA2 levels correlated with LDL levels but not with Tnl or CRP levels. Our results demonstrated dynamic alterations in Lp-PLA2 levels during the early stages of ACS and, therefore, indirectly support the hypothesis of an active role for Lp-PLA2 in the pathogenesis of ACS.

Blood levels of copeptin on admission predict outcomes in out-of-hospital cardiac arrest survivors treated with therapeutic hypothermia

Introduction

Prognostic stratification of cardiac arrest survivors is essential for the selection of the most appropriate therapeutic strategy. However, accurate early outcome predictions for this patient population remain challenging. At present, there is a lack of data examining the prognostic value of C-terminal provasopressin (copeptin) in cardiac arrest survivors.

Methods

A group of 40 out-of-hospital cardiac arrest survivors who were treated with endovascular hypothermia was analyzed. Copeptin levels were measured in blood samples taken at admission using a commercially available immunoassay. Neurological outcome was assessed at 30 days post admission according to the Cerebral Performance Category (CPC): CPC 1, no neurological deficit; CPC 2, mild to moderate dysfunction; CPC 3, severe dysfunction; CPC 4, coma; and CPC 5, death.

Results

Copeptin levels were significantly lower in patients with CPC 1 compared with CPC 2 or CPC 3 to CPC 5 (74.3 ± 14.4 pmol/l, 219.8 ± 33.9 pmol/l and 302.7 ± 52.1 pmol/l, respectively; P < 0.0001). Using an optimal cutoff value ≤ 217.9 pmol/l calculated from the receiver operating characteristic curve (area under curve = 0.801, 95% confidence interval = 0.644 to 0.910; P = 0.0001), the sensitivity of predicting survival with good neurological outcome was 78.6% and the specificity was 75.0%. Multiple logistic regression analysis revealed that a copeptin level > 217.9 pmol/l was an independent predictor of severe neurological dysfunction or death, with an adjusted odds ratio of 27.00 (95% confidence interval = 2.27 to 321.68; P = 0.009).

Conclusion

The present study found that copeptin levels have a significant prognostic value at the time of hospital admission, and are a promising diagnostic tool for predicting outcomes in out-of-hospital cardiac arrest survivors.

Nitrotyrosine and nitrate/nitrite levels in cardiac arrest survivors treated with endovascular hypothermia

The protective effect of therapeutic hypothermia in cardiac arrest survivors (CAS) has been previously well documented. Animal studies have indicated that attenuation of tissue oxidative stress (OS) may be involved in the mechanisms that lead to the beneficial effect of hypothermia. The extent of OS and nitric oxide (NO) production in adult CAS treated with endovascular hypothermia is, however, unknown. A total of 11 adult patients who experienced cardiac arrest out of hospital were included in the present study, and all were treated with mild hypothermia using the Thermogard XP (Alsius, USA) endovascular system. A target core temperature of 33 °C was maintained for 24 hours, with a subsequent rewarming rate of 0.15 °C per hour, followed by normothermia at 36.8 °C. Blood samples for the measurement of nitrotyrosine and nitrate/nitrite levels were drawn at admission and every 6 hours thereafter for two days. During the hypothermic period, the levels of nitrotyrosine and nitrates/nitrites were comparable with baseline values. During the rewarming period, serum levels of both parameters gradually increased and, during the normothermic period, the levels were significantly higher compared with hypothermic levels (nitrotyrosine, P<0.001; nitrates/nitrites, P<0.05). In our study, significantly lower levels of nitrotyrosine and nitrates/nitrites were demonstrated during hypothermia compared with levels during the normothermic period in adult CAS. These data suggest that attenuation of OS and NO production may be involved in the protective effect of hypothermia in adult CAS.