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.

Differences in clinical and echocardiographic parameters between paroxysmal and persistent atrial flutter in the AURUM 8 study: targets for prevention of persistent arrhythmia?

PURPOSE: Cavotricuspid isthmus-dependent atrial flutter (AFL) can occur in a paroxysmal or persistent pattern. The aim of this study was to identify clinical, echocardiographic, and electrophysiological risk factors independently associated with persistence of AFL. METHODS: Patients of the recently published AURUM 8 study with paroxysmal versus persistent AFL were compared with respect to clinical and echocardiographic baseline characteristics as well as procedural parameters. The AURUM 8 study is a randomized, multicenter clinical trial comparing the efficacy and safety of gold versus platinum-iridium 8-mm-tip ablation. AFL was paroxysmal in 218 patients and persistent in 210 patients. RESULTS: Univariate analysis revealed that patients with persistent AFL had higher New York Heart Association class (P = 0.002), shorter time since 1st AFL episode (median 0.18 vs 0.34, P = 0.037), a higher prevalence of previous coronary artery bypass grafting surgery (17% vs 9%, P = 0.02), left ventricular hypertrophy (17% vs 8%, P = 0.005), dyspnea during AFL (P < 0.001), mitral regurgitation (P = 0.002), tricuspid regurgitation (P = 0.049), and pulmonary hypertension (P = 0.01). Palpitations during AFL were less frequent in patients with persistent AFL (P = 0.001). Multivariate analysis revealed that age, weight, AFL diagnosis after initiation of class IC or III antiarrhythmic drugs for atrial fibrillation, history of left ventricular hypertrophy, dyspnea during AFL and mitral regurgitation on echocardiography were significant independent variables associated with persistent AFL. A history of atrial fibrillation and palpitations during AFL were independently associated with paroxysmal AFL. CONCLUSIONS: We were able to identify clinical and echocardiographic risk factors associated with persistence of typical AFL. Treatment of these risk factors can potentially not only prevent the transition from paroxysmal to persistent AFL, but maybe also the development or initiation of AFL in general.

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.

Therapy with renin-angiotensin system blockers after pulmonary vein isolation in patients with atrial fibrillation: who is a responder?

AIMS: The data on anti-arrhythmic effect of renin-angiotensin-aldesteron system blockers (RASB) in patients with atrial fibrillation (AF) are controversially discussed. The goal of this analysis was to identify cohort of patients with AF and hypertension, who may have benefit from RASB therapy after pulmonary vein isolation (PVI). METHODS: A total of 284 patients with AF and hypertension (paroxysmal AF [PAF]= 218, male = 185, age = 61 years, left ventricular ejection fraction = 60%, coronary artery disease = 42) considered for PVI were included. The patients with PAF were stratified according to time spent in AF (AF burden) within 3 months prior to admission ( 500 hours). Further patients were divided into two groups: (1) low-burden AF; (2) high-burden AF (PAF and persistent AF). In 195 patients, RASB therapy was administered. A 7-day continuous Holter electrocardiogram was performed after discharge, every 3 months thereafter and by symptoms. RESULTS: Preventive effect of RASB was revealed in whole group (112 out of 195 [57%] vs 36 out of 89 [40%]; P = 0.025) and was more pronounced in patients with low-burden AF (79 out of 112 [71%] receiving RASB vs 27 out of 55 [49%] being on other drugs; P = 0.013). However, efficiency of RASB failed in patients with high-burden AF (33 out of 83 on RASB [40%] vs nine out of 34 on other drugs [27%]; P = 0.328). CONCLUSIONS: Our data suggest that RASB appears to protect against AF recurrences after PVI in patients with low-burden paroxysmal AF. These results should be tested in a prospective study.

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.

Evaluation of atrial fibrillation burden before catheter ablation predicts outcome after pulmonary vein isolation.

BACKGROUND: Paroxysmal atrial fibrillation (PAF) is defined as recurrent AF terminating spontaneously within 7 days. This definition allows the consideration of any AF occurrence lasting < 7 days as paroxysmal, irrespective of the frequency and duration of episodes. The aim of this study was to investigate symptomatic AF burden (AFB) defined as total duration of symptomatic AF episodes within 3 months prior to abalation, for prediction of outcome after pulmonary vein isolation (PVI). METHODS: A total of 320 consecutive patients with symptomatic AF (PAF=244, men=214, age=58 y) were enrolled. AFB in patients with PAF was defined as time spent in AF within 3 months prior to PVI. After the AFB cut-off point was optimized at 500 h, patients with PAF were categorized into 2 groups: Group 1 - patients with AFB< 500 h (n=192), Group 2 - patients with AFB> or = 500 h (n=52). Patients with persistent AF (PersAF, n = 76) comprised control group (Group 3). PVI was performed either with irrigated tip catheter (n=215) or using cryoballoon (n=105). The endpoint of study was first documented recurrence of AF >30 sec. RESULTS: Symptomatic AFB was found to be appropriate for prediction of outcome after PVI. The freedom from AF within 2 years was observed in 69%, 31%, and 43% patients in Group 1, 2 and 3, respectively (Group 1 vs. Group 2, p < .001; Group 1 vs. Group 3, p< .001; Group 2 vs. Group 3, p = 0.46). CONCLUSIONS: Low AFB < 500 h /3 months was associated with better outcome after PVI. Patients with PAF and high AFB should be treated as patients with PersAF.

Pulmonary vein diameter reduction after radiofrequency catheter ablation for paroxysmal atrial fibrillation evaluated by contrast-enhanced three-dimensional magnetic resonance imaging.

BACKGROUND: Radiofrequency catheter ablation (RFCA) is a promising intervention to treat atrial fibrillation. However, pulmonary vein (PV) stenosis after RFCA has been reported. The aim of this study was to investigate the incidence and time course of pulmonary vein stenosis after RFCA within a period of 3 months. Contrast-enhanced magnetic resonance angiography (MRA) was used to visualize pulmonary veins and was compared with radiographic angiography. METHODS AND RESULTS: Forty-six consecutive patients with symptomatic paroxysmal atrial fibrillation had RFCA in the orifice of 138 pulmonary veins. Comparison of diameters measured in 44 untreated vessels either by radiographic angiography or with MRA established the reliability of MRA (r=0.934). MRA measurements revealed an incidence of relevant diameter reductions of > or =25% or stenosis of > or =50% after RFCA of 25 of 138 (18.1%) treated vessels 1 day and/or 3 months after ablation. A progression of diameter reduction after RFCA was observed in 8.3% (maximum 75%), whereas a regression was observed in 6.3% of treated PVs. Ablation at a radial angle of >180 degrees of a pulmonary vein orifice increased the risk of diameter reduction significantly compared with ablation at a radial angle < or =180 degrees (P=0.002). CONCLUSIONS: The occurrence and progression of PV stenosis is a potential significant complication of RFCA in the orifice of pulmonary veins. These findings may have an impact on the technical performance of this intervention. In addition, long-term studies will be necessary to evaluate lumen reduction over time. MRA is a noninvasive, reproducible imaging modality for this purpose.

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.

Decreased pulmonary perfusion in pulmonary vein stenosis after radiofrequency ablation: assessment with dynamic magnetic resonance perfusion imaging.

STUDY OBJECTIVES: The functional impact of pulmonary vein (PV) stenosis on pulmonary perfusion after radiofrequency ablation (RFA) for atrial fibrillation (AF) has not been systematically evaluated previously. Therefore, we correlated magnetic resonance (MR) pulmonary perfusion imaging with single-photon emission CT (SPECT) perfusion and with the degree of PV stenosis (PVS) apparent on MR angiography (MRA) after RF ablation. SETTING: Joint radiology-cardiology collaborative magnetic resonance unit at the Kerckhoff Heart Center. DESIGN AND PATIENTS: This was a cohort study of 110 patients who were routinely examined by MRA after RFA for AF, whereby 51 patients with a PV diameter reduction of > 25% or with clinical symptoms (ie, dyspnea and cough) were enrolled into the study. Patients were examined at follow-up by MR perfusion imaging and MRA, and the results were compared to those from patients who underwent SPECT scanning and from a control group of 26 untreated patients. Twelve patients underwent PVS dilatation as well as 22 sequential follow-up examinations. METHODS: Pulmonary perfusion was evaluated using a dynamic contrast-enhanced three-dimensional MR perfusion sequence (1.5 T, 2.5-s temporal resolution, and 0.05 cm spatial resolution), and high-resolution, contrast-enhanced MRA was performed to measure PV diameter. PV dilatation was performed using an angioplasty catheter that was 8 to 10 mm in diameter. RESULTS: The localization and extent of perfusion defects measured by MRI or SPECT scanning were precisely matched. MR perfusion imaging detected 20 of 21 perfusion defects (sensitivity, 95.2%; specificity, 100%). PVSs and perfusion deficits correlated closely and showed the following threshold: perfusion decreased substantially in PVs 6 mm in diameter. After PVS dilatation, perfusion was restored partially after weeks, and complete normalization was seen in 4 of 12 patients (33%). CONCLUSIONS: PVSs caused severe perfusion deficits, which were reliably demonstrated by MR perfusion imaging. Clinical symptoms correlated better with MR perfusion than they did with MRA. The combination with MRA to assess underlying PVS allowed a "one-stop-shopping" MRI procedure to be carried out. The results led to alterations of RFA techniques, and therefore MRA and MR perfusion imaging may be beneficial in patient follow-up and in evaluating new ablation techniques.

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.

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.