The slope of the initial temperature drop predicts acute pulmonary vein isolation using the second-generation cryoballoon.

AIMS: There is no objective, early indicator of occlusion quality, and efficacy of cryoballoon pulmonary vein isolation. As previous experience suggests that the initial cooling rate correlates with these parameters, we investigated the slope of the initial temperature drop as an objective measure. METHODS AND RESULTS: A systematic evaluation of 523 cryoapplications in 105 patients using a serial ROC-AUC analysis was performed. We found the slope of a linear regression of the temperature-time function to be a good predictor (PPV 0.9, specificity 0.72, sensitivity 0.71, and ROC-AUC 0.75) of acute isolation. It also correlated with nadir temperatures (P< 0.001, adjusted R2= 0.43), predicted very low nadir temperatures, and varied according to visual occlusion grades (ANOVA P< 0.001). CONCLUSIONS: About 25 s after freeze initiation, the temperature-time slope predicts important key characteristics of a cryoablation, such as nadir temperature. The slope is the only reported predictor to actually precede acute isolation and thus to support decisions about pull-down manoeuvres or aborting a cryoablation early on. It is also predictive of very low nadir temperatures and phrenic nerve palsy and thus may add to patient safety.

Clinical impact of a novel three-dimensional electrocardiographic imaging for non-invasive mapping of ventricular arrhythmias-a prospective randomized trial.

AIMS: ECVUE™ technology, a novel, three-dimensional, non-invasive mapping system, offers a unique arrhythmia characterization and localization. We sought to evaluate the clinical impact of this system in routine clinical mapping and ablation of ventricular arrhythmias (VAs). METHODS AND RESULTS: Patients with monomorphic premature ventricular contractions with or without monomorphic ventricular tachycardia were enrolled prospectively and randomized into two groups: ventricular ectopy localization using either 12-lead electrocardiogram (ECG) algorithms or with ECVUE™, followed by conventional guided ablation. Forty-two patients were enrolled in the study. The ECVUE™ system accurately identified both the chamber and sub-localized the VA origin in 20 of 21 (95.2%) patients. In contrast, using 12-lead ECG algorithms, the chamber was accurately diagnosed in 16 of 21 (76.2%) patients, while the arrhythmia origin in only 8 of 21 (38.1%), (P = 0.001 vs. ECVUE™). Acute success in ablation was achieved in all patients. Regarding the number of radiofrequency-energy applications (in total 2 vs. 4, P = 0.005) in the ECVUE™ arm, ablation was more precise than the ECG group which used standard of care activation and pace mapping-guided ablation. Three months success in ablation was 95.2% for the ECVUE™ and 100% for the ECG group (P = ns). Time to ablation was 35.3 min in the conventional arm and 24.4 min in ECVUE Group, (P = 0.035). The X-ray radiation exposure was 3.21 vs. 0.39 mSv, P = 0.001 for the ECVUE™ group and ECG group. CONCLUSION: ECVUE™ technology offers a clinically useful tool to map VAs with high accuracy and more targeted ablations superior to the body surface ECG but had significantly higher radiation exposure due to computed tomography scan.

Learning curve in cryoballoon ablation of atrial fibrillation: eight-year experience.

BACKGROUND: We analyzed the procedural experience cryoballoon ablation (CBA) of atrial fibrillation (AF) gained over 8 years in a high-volume centre to understand the influence of the learning curve on feasibility, safety and clinical outcome. METHODS AND RESULTS: In 424 patients (62% male) with drug-refractory AF, CBA was performed between 2005 and 2012. The analyzed period was divided into 8 calendar years. The endpoint of the study was arrhythmia recurrence after the 3-month blanking period in the 1-year follow-up since the index procedure, in the absence of anti-arrhythmic drugs class I and III. A combined AF type, Left Atrium size, Renal insufficiency, MEtabolic syndrome, cardiomyopathy (ALARMEc) risk score was calculated for each patient. The overall 1-year success rate of a single CBA was 73%. Continuous increase in 1-year success rate was observed with successive years of the study. The gradual improvement in outcome was related to gradual fall in ALARMEc risk score in successive patients. A continuous decrease in fluoroscopy and procedure time was observed in each subsequent year. CONCLUSIONS: CBA, followed by the proper selection of patients, facilitates a satisfactory outcome, especially in patients at an early stage of PV-trigger-dependent AF. Still, as with each new technology, it requires completion of a learning curve.

Score associated with the outcome after multiple ablation procedures in patients with atrial fibrillation.

BACKGROUND: Catheter ablation (CA) of atrial fibrillation (AF) is now established therapeutic option. Multiple procedures (MPs) are often needed to achieve the satisfactory outcome. The aim of the study was to assess the outcome after MPs in AF patients categorized to risk-score groups. METHODS: We followed a cohort of consecutive 911 (69% male; median 59 years) patients with AF (58% paroxysmal) who had CAAF performed. ALARMEC (Atrial fibrillation type, Left Atrium size, Renal insufficiency, MEtabolic syndrome, cardiomyopathy) risk score was calculated for each patient. The end point was maintenance of sinus rhythm at the follow-up of 60 months. RESULTS: We performed 1,199 CAAF procedures. One, two, and three procedures were performed in 663 (73%), 208 (23%), and 40 (4%) patients, respectively. Outcome after the first procedure (56%) was improved with MPs (76%). MPs > 2 were performed in 1%, 3%, 5%, 6%, and 10% patients with ALARMEC score of 0, 1, 2, 3, and 4, respectively. MPs were successful in 89%, 86%, 81%, 65%, and 43% of patients with ALARMEC score of 0, 1, 2, 3, and 4, respectively. Outcome in 174 (19%) patients on antiarrhythmic drugs (AADs) was 85%, 68%, 75%, 44%, and 39% in ALARMEC score: 0, 1, 2, 3, and 4, respectively. Outcome in 737 (81%) patients without AAD was 90%, 85%, 80%, 77%, and 69% in ALARMEC score of 0, 1, 2, 3, and 4, respectively. CONCLUSION: The moderate success rate after index procedure of CAAF can be further improved with multiple ones and AAD.

Cryoballoon ablation of paroxysmal atrial fibrillation: 5-year outcome after single procedure and predictors of success.

AIMS: Long-term efficacy following cryoballoon (CB) ablation of atrial fibrillation (AF) remains unknown. This study describes 5 years follow-up results and predictors of success of CB ablation in patients with paroxysmal atrial fibrillation (PAF). METHODS AND RESULTS: In total, 163 patients were enrolled with symptomatic, drug refractory PAF. Pulmonary vein isolation (PVI) with CB technique was performed. Primary endpoint of this consecutive single-centre study was first electrocardiogram-documented recurrence of AF, atrial tachycardia or atrial flutter (AFLAT). Five years success rate after single CB ablation was 53%. In 70% of the patients acute complete PVI was achieved with a single 28 mm balloon. The univariate predictors of AFLAT recurrence were (1) size of left atrium, with normalized left atrium (NLA) ≥10.25 [hazard ratios (HR) of 1.81, 95% confidence interval (CI): 1.28-2.56] when compared with NLA <10.25 (35% vs. 53%, P = 0.0001) and (2) renal function, with impaired glomerular filtration rate (GFR) <80 ml/min (HR of 1.26, 95% CI: 1.02-1.57) when compared with GFR ≥80 ml/min (45% vs. 53%, P = 0.041). Normalized left atrium ≥10.25 was the sole independent predictor for outcome (HR 2.11; 95% CI: 1.34-3.31; P = 0.0001). CONCLUSIONS: Sinus rhythm can be maintained in a substantial proportion of patients with PAF even 5 years after circumferential PVI using CB ablation. The rate of decline in freedom from AFLAT was highest within the first 12 months after the index procedure. The patients with enlarged left atrium and/or impaired renal function have lower outcome.

Repeated catheter ablation of atrial fibrillation: how to predict outcome?

BACKGROUND: Pre-procedural predictors (PP) of atrial fibrillation (AF) recurrence (AFR) after repeated catheter ablation of AF (RCAF) are unknown. The aim of this study was identification of PP of outcome after RCAF. METHODS AND RESULTS: In 213 patients (73% male) with drug-refractory AF (47% paroxysmal AF; PAF) RCAF was performed. CHADS2, CHA2DS2-VASc and ALARMEc (AF type, Left Atrium size, Renal insufficiency, MEtabolic syndrome, cardiomyopathy) scores were calculated for each patient. Complete success was defined as no AFR. After RCAF, 125 patients (59%) were free of atrial flutter or atrial tachycardia (AFLAT) on long-term follow-up (FU). The univariate predictors of AFR were: type of AF (non-PAF vs. PAF, P=0.001), normalized left atrium area (NLA ≥10.25 vs. NLA <10.25, P=0.012) and estimated glomerular filtration rate (<68ml/min vs. ≥68ml/min, P=0.048). The independent predictors of AFLAT-free survival after RCAF were non-PAF (P=0.002) and NLA ≥10.25 (P=0.018). Among combined predictors, only ALARMEc score, and neither CHADS2 or CHA2DS2-VASc, predicted outcome after RCAF (P<0.0001). CONCLUSIONS: RCAF results in a moderate success rate on very long-term FU. Lower success was observed in patients with non-PAF and enlarged LA. ALARMEc score allows for clear description of expected outcome after RCAF.

Ipsilateral circumferential radiofrequency ablation of atrial fibrillation with irrigated tip catheter: long-term outcome and pre-procedural predictors.

BACKGROUND: Predictors of long-term outcome of atrial fibrillation (AF) ablation are unknown. The predictors of 5-year follow-up (FU) after single ipsilateral circumferential antrum pulmonary vein isolation (PVI) with irrigated tip catheter were investigated. METHODS AND RESULTS: In 356 patients (74% male) with AF (44% paroxysmal AF [PAF]) PVI was performed. Success was defined as absence of AF, atrial flutter or tachycardia (AFLAT) recurrence. A total of 161 patients (45%) were free of AFLAT. The univariate predictors of AFLAT recurrence were: type of AF (non-PAF vs. PAF, P=0.0001), size of LA (normalized left atrium area [NLA] ≥11.5 vs. NLA <11.5, P=0.0001), renal function (glomerular filtration rate [GFR] <68ml/min vs. GFR ≥68ml/min, P=0.001) and hypertension (HT vs. no HT, P=0.025). The independent predictors of AFLAT-free survival were non-PAF (hazard ratio [HR], 1.67; 95% confidence interval [CI]: 1.23-2.26, P=0.0005), NLA ≥11.5 (HR, 1.40; 95% CI: 1.03-1.90, P=0.007) and GFR <68ml/min (HR, 1.70; 95% CI: 1.21-2.37, P=0.008). CONCLUSIONS: Single PVI results in a moderate success rate in patients with AF during 5-year FU without the use of a 3-D mapping system. Higher success was observed in patients with PAF, non-enlarged LA and good renal function.

Impact of impaired renal function and metabolic syndrome on the recurrence of atrial fibrillation after catheter ablation: a long term follow-up.

BACKGROUND: The goal of this study was to analyze impact of metabolic syndrome (MetS) and impaired renal function on long-term follow-up after catheter ablation of atrial fibrillation (AF). METHODS AND RESULTS: A total of 702 consecutive patients with AF (age = 58 year, history of AF = 5 year, male = 478, paroxysmal atrial fibrillation = 416, coronary artery disease = 62, hypertension = 487) considered for catheter ablation were enrolled in the study. The MetS was diagnosed at admission in 276 patients. The renal function was estimated by glomerular filtration rate (eGFR). Pulmonary vein isolation (PVI) was performed either with cryoballoon technique (n = 260) or circumferential PVI (n = 442) with a 3.5-mm irrigated tip catheter. A 7-day-Holter electrocardiogram was performed at each follow-up visit. Any episode of documented AF after an initial 3-month blanking period was considered as clinical endpoint. Out of 702 patients, 370 (52.7%) were free of AF recurrences at median follow-up of 15 six interquartile range (12.7-42.3) months. The patients with MetS had significantly lower success rate than those without (128/276 (46.4%) vs 242/426 (56.8%), P = 0.006). Among 103 patients with eGFR < 68 mL/min only 35 (34%) were free of recurrences compared with 335/599 (55.9%) in patients with GFR ≥ 68 mL/min (P = 0.001). Both parameters were revealed in multivariate analysis to be independent predictors for outcome after catheter ablation. CONCLUSION: The results of our study clearly demonstrated that outcome after 1st catheter ablation of AF is poor in patients with MetS and/or impaired renal function. This observation has a potential clinical impact for the follow up management of these patients.

MEDAFI-Trial (Micro-embolization during ablation of atrial fibrillation): comparison of pulmonary vein isolation using cryoballoon technique vs. radiofrequency energy.

AIMS: Cerebral embolism is a possible serious complication during catheter ablation of atrial fibrillation (AF). The purpose of this prospective pilot study was to analyse the incidence and possible impact of cryo ablation on cerebral lesions and possible differences to radiofrequency (RF) ablation during pulmonary vein isolation (PVI). METHODS AND RESULTS: Pulmonary vein isolation was performed in 89 patients, either with the cryoballoon technique (n = 45) or with RF ablation (n = 44). Phenprocoumon was stopped 3 days before intervention and replaced by subcutaneous low-molecular-weight heparin. During the catheter procedure, an infusion of unfractionated heparin was maintained to achieve an activated clotting time (ACT) of > 300 s. Cerebral magnetic resonance imaging scans were performed 1 day before and after PVI, and at 3-month follow-up. Chronic lesions were observed in 11 patients (12.3%) before PVI without statistically significant difference between the two groups. None of the patients had neurological symptoms during or following the procedure. Seven patients (7.9%) developed acute lesions 1 day after PVI, without statistically significant difference between the group treated by cryoenergy (8.9%) and RF ablation (6.8%). Patients with acute lesions were significantly older compared with those without acute cerebral lesions. No additional cerebral lesions during follow-up were observed. CONCLUSION: A considerable portion of patients with AF but without any neurological symptoms had chronic cerebral lesions before PVI. Additional acute lesions could be added after the procedure. Both ablation techniques showed additional cerebral acute lesions with no neurological symptoms after PVI.

Electrocardiographic and further predictors for permanent pacemaker requirement after transcatheter aortic valve implantation.

The objective of this study was to identify electrocardiographic (ECG) and further predictors for atrioventricular (AV) block with a need for pacemaker (PM) implantation after transcatheter aortic valve implantation (TAVI). Pre- and post-procedural ECGs of patients with severe aortic stenosis and ongoing TAVI were investigated in a prospective study. From 50 consecutive patients enrolled in the study (mean age 80 +/- 6 years, 46% men), 17 (34%) experienced an AV block with subsequent requirement of a permanent PM [16 of 36 (44.4%) with CoreValve System and 1 of 14 (7.1%) with Edwards Sapiens System]. In patients with right bundle branch block (RBBB), PM implantation had to be performed more frequently [6 of 6 (100%) with CoreValve System and none with Edwards Sapiens System], P = 0.005. An AV block (Mobitz II second degree and third degree) occurred mostly within the first 24 h (range: Days 0-13) after the index procedure. No recovery of AV conduction with a change in PM indication occurred in a mean follow-up time of 13 +/- 6 days. Our data demonstrate that patients with pre-operative RBBB and those receiving CoreValve prosthesis are at a significantly higher risk for PM implantation after TAVI. Therefore, patients with the presence of RBBB before TAVI may be at lower risk for PM implantation using the Edwards Sapiens System.

Pulmonary vein antrum isolation and terminal part of the P wave.

BACKGROUND: Delayed interatrial conduction, manifested on the electrocardiogram as a P wave >or=110 ms (interatrial block, IAB), is highly prevalent and associated with atrial fibrillation (AF). It is correlated with P-terminal force (Ptf; product of the duration and amplitude of the negative terminal phase of the P wave in lead V1). Our purpose was to describe the modifications of the P-wave duration and Ptf after pulmonary vein antrum isolation (PVAI) in patients with paroxysmal AF. METHODS: PVAI was performed in 45 patients with paroxysmal AF, either with the cryoballoon technique (n = 15) or radiofrequency ablation (n = 30). Electrocardiograms were recorded before PVAI, 3 and 6 months after ablation. RESULTS: From the sample (median age 60 [53; 66] years; female 40%), median P-wave duration was 122 [114; 134] ms before PVAI and 116 [106; 124] ms at 3-month follow-up (P < 0.001). IAB was observed in 42 patients (93.3%) before ablation and in 31 patients (68.9%) at 3-month follow-up. Median Ptf was 0.047 [0.020; 0.068] before ablation and 0.013 [0.004; 0.025] at 3-month follow-up (P < 0.001). Twenty-six patients (57.8%) had a Ptf > 0.04 mV x ms before ablation and only one (2.2%) at 3-month follow-up. P-wave duration and Ptf were not significantly modified between 3- and 6-month follow-up. CONCLUSION: The terminal part of the P wave is modified after PVAI, perhaps due to the loss of pulmonary vein antrum signals. P-wave duration and Ptf must be carefully interpreted after such a procedure. The prognostic value of these modifications should be evaluated.

Pulmonary vein stenting for the treatment of acquired severe pulmonary vein stenosis after pulmonary vein isolation: clinical implications after long-term follow-up of 4 years.

INTRODUCTION: Severe pulmonary vein stenosis (PVS) after catheter ablation of atrial fibrillation (AF) is a well-recognized complication with a further reported incidence of 1.3%. The preferred therapy for symptomatic PVS is pulmonary vein (PV) angioplasty, but this treatment modality is followed by restenosis in 44-70%. Whether there is additional long-term benefit from PVS stenting is uncertain. The aim of this study was the evaluation of the long-term success after PV stenting of severe stenosis. METHODS AND RESULTS: Ten patients (pts) with 13 PVS were prospectively evaluated. PV stenting was performed with Palmaz Genesis stents. Magnetic resonance imaging (MRI), lung perfusion scans, and CT-scans were performed before, directly after, and every 12 months thereafter. Primary endpoint of the study was the occurrence of restenosis after PV stenting. After a median follow-up of 47.7 (IQRs 25/75 47.2-48.5) months, the primary endpoint was achieved in 3 out of 13 PVs (23% of the treated PVs). We observed two in-stent restenosis 2 and 4 years after PV stenting. These pts experienced onset of dyspnea some weeks before. After an additional balloon angioplasty, the in-stent restenosis was resolved. In one asymptomatic patient, we observed an occlusion of the PV stent 13 months poststenting. Normalization of lung perfusion was noted 4 years after PV stenting versus directly poststenting in all pts without in-stent restenosis (n = 7). CONCLUSION: PVS stenting with stent sizes >or=10 mm seems to be an adequate therapy modality for treatment of severe acquired PVS. Late in-stent restenosis after PVS stenting can occur. The normalization of the initially disturbed lung perfusion scan is possible and remains stable, even 4 years after PVS stenting.

Predictors of early and late left atrial tachycardia and left atrial flutter after catheter ablation of atrial fibrillation: long-term follow-up.

BACKGROUND: The aim of the study was identification of the predictors of left atrial tachycardia and left atrial flutter (LATAFL) after radiofrequency catheter ablation of atrial fibrillation (CAAF). METHODS: We followed 598 patients (71% male, 41% paroxysmal AF; median follow-up: 36 months) after a single step-wise CAAF procedure. The time to first documented LATAFL lasting longer than 30 s, documented in any kind of electrocardiography (ECG), was defined as an end-point. RESULTS: A single CAAF procedure resulted in LATAF in 58 (10%) patients. Additional lesions were performed in 275 (46%) patients. Early LATAFL recurrence (£ 3 months since the index procedure) was observed in 11 (2%) patients. Late LATAFL (> 3 months) was noted in 47 (8%) patients. The univariate predictors of LATAFL recurrence were: type of AF (p = 0.003), the size of LA (p = 0.002) and the type of procedure (p = 0.0001). The identified single independent predictors of LATAFL recurrence were enlarged LA (p = 0.001) and mul-tiple (≥ 2) additional lesions performed during the index procedure (p < 0.0001). CONCLUSIONS: Higher rate of LATAFL recurrence was observed in patients with non-paroxysmal AF, enlarged LA and any additional lesions performed. Two independent predictors of LATAFL recurrence after CAAF were: the enlarged LA and multiple (≥ 2) additional lesions performed during the index procedure.

Cryoballoon ablation of atrial fibrillation: How important is the proper selection of patients?

BACKGROUND: Relation between pre-procedural selection of patients and the success rate after a single cryoballoon ablation (CAB) procedure is unknown. METHODS: CAB was performed in 378 (65% male, median age 58 years, 85% paroxysmal atrial fibrillation [AF]) consecutive patients with symptomatic and drug refractory AF. The combined ALARMEc (Atrial fibrillation type, Left Atrium size, Renal insufficiency, Metabolic syndrome, cardiomyopathy) risk score was calculated for each individual patient. The end-point of the study was the first AF, atrial flutter or atrial tachycardia recurrence after the 3-month blanking period in the 1-year follow-up since the index procedure, in the absence of anti-arrhythmic (class I and III) therapy. RESULTS: Single and multi-catheter approach was used in 79% and 21% of patients, respectively. The acute success rate with single and multi-catheter approach was 79% and 99%, respectively. The overall 1-year success rate after a single CAB procedure was 70%. The 1-year outcome was: 83%, 70%, 60%, 40% and 29% in patients with ALARMEc risk score: 0, 1, 2, 3 and 5, respectively. Total rate of complications was 11%, including transient phrenic nerve palsy in 9.5% of cases. CONCLUSIONS: Multi-catheter approach was needed in 21% of patients to achieve acute pulmonary vein isolation. Patients with low (≤ 1) ALARMEc risk score, preferably young individuals with sole paroxysmal AF (ALARMEc = 0), are best candidates for CBA procedure. Performing CBA in patients with higher (> 2) ALARMEc risk score should be avoided. Phrenic nerve palsy was a transient complication.

Cryoballoon ablation in young patients with lone paroxysmal atrial fibrillation.

INTRODUCTION AND OBJECTIVES: Long-term efficacy following cryoballoon ablation of lone paroxysmal atrial fibrillation remains unknown. We describe long-term follow-up results of the single cryoballoon ablation procedure. METHODS: Pulmonary vein isolation was performed in 103 patients (72 male; median age 52 years) with symptomatic lone paroxysmal atrial fibrillation. The end-point of this observational cohort study was first electrocardiogram-documented recurrence of arrhythmia (atrial fibrillation, atrial tachycardia, or atrial flutter) during the 5-year follow-up, in the absence of anti-arrhythmic treatment. RESULTS: Acute complete pulmonary vein isolation was achieved in 86% of the patients with a single cryoballoon. The 6-month, 1-year, and 5-year success rate after a single procedure was 94%, 91%, and 77%, respectively. Arrhythmia recurrence was observed in 24 cases at a median of 14.8 months [range, 8.0-16.8 months]. Thirteen symptomatic patients were well controlled on beta-blockers only. Seven symptomatic patients had anti-arrhythmic treatment (class IC in 5 patients; dronedarone in 2 patients) introduced during the blanking period. Two of them had early arrhythmia recurrence within the blanking period only; they were arrhythmia-free in further follow-up on dronedarone. The rate of complications was relatively low and included a 4.8% incidence of transient phrenic nerve palsy. CONCLUSIONS: A single cryoballoon ablation procedure for lone paroxysmal atrial fibrillation resulted in high rates of acute, medium-term, and long-term efficacy. The rate of complications is relatively low and includes a 4.8% incidence of transient phrenic nerve palsy.

Atrial Fibrillation and Renal Disease.

Co-incidence of atrial fibrillation and renal dysfunction in general population is described in many epidemiological studies. Major issue is optimal anticoagulation in patients with atrial fibrillation and renal disease warranting balance between risks of ischemic stroke and hemorrhages. The second issue is catheter ablation of AF patients with renal dysfunction. Both issues are discussed in this paper.

Major determinants of myocardial injury after pulmonary vein isolation with radiofrequency ablation.

BACKGROUND: Radiofrequency (RF) current is used as a common energy source to perform pulmonary vein isolation (PVI) in patients with atrial fibrillation. We applied measurements of the blood concentration of cTnI as a surrogate parameter for the injured cell mass. AIM: To clarify which parameters are major determinants of myocardial injury, estimated by cTnI, after PVI with RF ablation. METHODS: The study population consisted of 82 consecutive patients in whom PVI with RF ablation was performed. In 41 patients, additional linear lesions (LL) were needed. Blood samples were obtained during venous puncture before a procedure and a further one, six and 24 hours after ablation. RESULTS: Pathological cTnI values were observed in all patients in the first hour and further increased in time. The median of peak cTnI value in the LL group was significantly (p 〈 0.05) higher than the respective value in patients without LL made: 1.16 (0.85;1.98) and 0.94 (0.65;1.14) ng/mL, respectively. Significantly higher cTnI values (p = 0.043) were observed in patients who maintained sinus rhythm in long term follow-up. CONCLUSIONS: The only independent predictor of myocardial injury after PVI with RF ablation, expressed as an increase in cTnI level, is cumulative energy applied. The larger the myocardial injury, the greater the PVI effectiveness.

Which standard biomarkers are useful for the evaluation of myocardial injury after pulmonary vein isolation with cryoballoon?

BACKGROUND: Many studies have used creatinine kinase (CK), myocardial bound for CK (CK-MB), and cardiac troponin I (cTnI) and T (cTnT) to evaluate myocardial cells injury after ablation. We applied measurements of the blood concentration of cardio-specific biomarkers as surrogates for the injured cell mass. AIM: To clarify which of the standard biomarkers are useful in the evaluation and quantification of lesions produced by cryoballoon ablation (CBA) during pulmonary vein isolation. METHODS: The CBA was performed in 33 patients with atrial fibrillation. Blood samples were obtained before CBA and one, six, and 24 h after CBA. We analysed CK, CK-MB and cTnI. RESULTS: A significant increase of all biomarkers was observed at each hour of collection as compared to the baseline measurement. Maximum median peak levels occurred at 6 h. Pathological values of CK, CK-MB and cTnI were observed in 94%, 100% and 100% of patients, respectively. Both maximum CK and CK-MB values correlated with median temperature (p < 0.05) reached during CBA. Additionally, CK-MB correlated with total cryo-time (p < 0.03). CONCLUSIONS: The CK-MB is the best biochemical marker for the evaluation of myocardial injury after CBA. The cTnI can be useful as an additional parameter of myocardial injury after CBA.

Limitations of biomarkers serum levels during pulmonary vein isolation.

INTRODUCTION AND OBJECTIVES: Several biomarkers have been used for evaluation and quantification of myocardial injury after effective ablation. We studied possible different thermal stability and usability of the proteins released by cardiac cells injured by different energy sources. METHODS: Firstly, we tested in vitro thermal stability of creatinine kinase (CK), myocardial bound creatinine kinase (CKMB), cardiac troponins I (cTnI) and cardiac troponins T (cTnT) in collected blood samples from 15 patients (pts) with confirmed ST-segment elevated myocardial infarction (STEMI). Secondly, the biomarkers were collected and analyzed in 82 pts treated with radiofrequency ablation (RFA) and in 79 pts treated with cryo-balloon ablation (CBA). RESULTS: In vitro experiment showed that all biomarkers were stable in low temperature of -30(o)C. Troponins were stable in the high temperatures analyzed. A substantial drop in CK and CKMB levels were measured at 50°C and 40° C, respectively. In vivo study showed that the increase in CKMB levels was highly significant in CBA pts only. Pathological CKMB values were observed in 24% of RFA pts and 98% of CBA pts. Pathological cTnI values were observed in all pts and the rise in cTnI levels was highly significant in both groups after ablation. CONCLUSIONS: Both in vitro and in vivo results show that CKMB cannot be used for quantitative determination of myocardial injury produced by radiofrequency energy. Only cardiac troponins reflect myocardial injury, regardless of energy source, and may be considered in future studies for comparison of biomarkers effects of cryo versus radiofrequency ablation.

Acute and long-term results of PVI at antrum using a novel high-density mapping catheter without help of 3D electro-anatomic mapping in patients with paroxysmal and chronic atrial fibrillation.

PURPOSE: Multi-electrode circumferential mapping catheters have been developed by several manufacturers to facilitate catheter ablation procedures for atrial fibrillation (AF). We tested the effectiveness and safety of a conventional, fully endocardial electrogram-guided circumferential antrum isolation (PVI) with a novel mapping device. METHODS: The study enrolled 250 consecutive patients with paroxysmal or chronic AF. High-density (HD) mapping of the pulmonary veins was performed with the HD Mesh Mapper (HDMM; Bard Electrophysiology, Lowell, MA, USA). The device was not constructed for radiofrequency energy delivery. Antral PVI was performed by irrigated radiofrequency application around the HDMM. Entry and exit conduction block, as well as decreased local electrode amplitude, were endpoints for acute successful ablation. Primary endpoint of the study was the AF free event probability during follow-up. As secondary endpoints, the acute results and related complications were determined. RESULTS: In 984 of 1,002 pulmonary vein (PV, 98.2%), signals were characterized as PV potentials by mapping the proximal part of the PV and the antrum. We achieved a complete antrum ablation in front of the 25-mm ring of the MESH Mapper in 95% of the PV in all patients. In difficult anatomic relationships, the repositioning of the mapping catheter could be necessary. The median follow-up time was 20.8 and 15.6 months in patients with paroxysmal and chronic AF, respectively. Log Rang test revealed a probability to be free from AF episodes of 71.2% and 49.4% after one ablation procedure and improved in chronic AF after a second procedure (71.1%). CONCLUSION: Our study demonstrates satisfactory success rate regarding the safety and long-term results in patients both with paroxysmal and persistent AF when a 3D mapping system is not being implemented. The study underlines the importance of a continuous signal analysis during the ablation procedure even with a conventional mapping system.