Cryoballoon ablation for pulmonary vein isolation in patients with atrial fibrillation: preliminary results using novel short-tip cryoballoon.

PURPOSE: In this study, we aimed to report our preliminary experience regarding the impact of the novel short-tip (ST) cryoballoon (CB) on procedural efficacy and signal quality during pulmonary vein (PV) isolation for both paroxysmal and persistent atrial fibrillation. METHODS: Between March, 2015, and August, 2015, we enrolled a total of 64 patients (47 patients male, 73 %) with a mean age of 60 ± 11 years. In the study population, 31 patients (48 %) underwent PVI using Advance (ADV) CB and 33 (52 %) patients with ST CB. In all patients, a 28-mm balloon was used. RESULTS: Acute procedural success rates were 100 % for the entire study population. A statistically insignificant increase in the percentage of PV signal recordings was observed with ST CB in all PVs compared to ADV CB [88 vs. 81 % for left superior PV (LSPV), 82 vs. 78 % for left inferior PV (LIPV), 85 vs. 84 % for right superior PV (RSPV), 82 vs. 71 % for right inferior PV (RIPV), p < 0.05]. Additionally, the difference in minimum temperature reached during the procedure per PV was not statistically significant between ST CB and ADV CB except the LIPV (LSPV -44.2 ± 5.9 vs. -45.6 ± 5.3 °C, p = 0.970; LIPV -38.7 ± 4.6 °C vs -44.6 ± 6.8 °C, p < 0.001; RSPV -45.6 ± 7.4 °C vs.-47.2 ± 6.1 °C, p = 0.168; RIPV -41.4 ± 5.1 °C vs.-43.7 ± 6.3 °C, p = 0.360). Time to isolation for each PV was similar between ST and ADV CB (p > 0.05). CONCLUSION: Our preliminary findings indicated similar acute procedural success for the novel ST CB compared with second generation ADV CB. The increase in the ratio of PV signal recordings obtained during the PVI using the novel ST CB was not significant.

Cryoballoon Ablation for Pulmonary Vein Isolation in Patients With Persistent Atrial Fibrillation: One-Year Outcome Using Second Generation Cryoballoon.

BACKGROUND: Data regarding the freedom from atrial fibrillation (AF) in the follow-up of persistent AF patients is limited. The second-generation cryoballoon has better cooling properties compared with first-generation cryoballon. In this study, we aimed to assess the medium-term efficacy of second-generation cryoballoon in patients with persistent AF. METHODS AND RESULTS: A total of 100 patients (63±10 years, 80% male) with symptomatic persistent AF, despite ≥1 antiarrhythmic drug(s), who were scheduled for pulmonary vein isolation using second-generation cryoballoon were enrolled in this study. Follow-up was based on outpatient clinic visits, including Holter ECGs. Recurrence was defined as a symptomatic or documented arrhythmia episode of >30 seconds excluding a 3-month blanking period. As a result, 393 pulmonary veins (7 patients with common ostium) were successfully isolated. Mean procedural and fluoroscopy times were 96.2±21.3 and 19.7±6.7 minutes, respectively. Phrenic nerve palsy occurred in 3% (3/100) of the patients. At a mean follow-up duration of 10.6±6.3 months, 67% of the patients were in sinus rhythm. Stepwise multivariable Cox proportional hazard regression analysis showed that early AF recurrence (hazard ratio 3.83, 95% confidence interval 1.91-7.68, P<0.001) was the only independent predictor for late AF recurrence apart from other clinical and echocardiographic variables. CONCLUSIONS: Our findings indicated that second-generation cryoballoon use is associated with favorable outcomes in patients with persistent AF. Recurrence at blanking period was the only predictor of long-term AF recurrence.

Incidence of asymptomatic intracranial embolic events after pulmonary vein isolation: comparison of different atrial fibrillation ablation technologies in a multicenter study.

OBJECTIVES: We compared the safety of different devices by screening for subclinical intracranial embolic events after pulmonary vein isolation with either conventional irrigated radiofrequency (RF) or cryoballoon or multielectrode phased RF pulmonary vein ablation catheter (PVAC). BACKGROUND: New devices specifically designed to facilitate pulmonary vein isolation procedures have recently been introduced. METHODS: This prospective, observational, multicenter study included patients with symptomatic atrial fibrillation referred for pulmonary vein isolation. Ablation was performed using 1 of the 3 catheters. Strict periprocedural anticoagulation, with intravenous heparin during ablation to achieve an activated clotting time >300 s, was ensured in all patients. Cerebral magnetic resonance imaging was performed before and after ablation. RESULTS: Seventy-four patients were included in the study: 27 in the irrigated RF group, 23 in the cryoballoon group, and 24 in the PVAC group. Total procedure times were 198 ± 50 min, 174 ± 35 min, and 124 ± 32 min, respectively (p < 0.001 for PVAC vs. irrigated RF and cryoballoon). Findings on neurological examination were normal in all patients before and after ablation. Post-procedure magnetic resonance imaging detected a single new embolic lesion in 2 of 27 patients in the irrigated RF group (7.4%) and in 1 of 23 in the cryoballoon group (4.3%). However, in the PVAC group 9 of 24 patients (37.5%) demonstrated 2.7 ± 1.3 new lesions each (p = 0.003 for the presence of new embolic events among the 3 groups). CONCLUSIONS: The PVAC is associated with a significantly higher incidence of subclinical intracranial embolic events. Further study of the causes and significance of these emboli is required to determine the safety of the PVAC.

Predictive value of B-type natriuretic peptide levels in patients with paroxysmal and persistent atrial fibrillation undergoing pulmonary vein isolation.

BACKGROUND: Atrial fibrillation (AF) is the most common cardiac arrhythmia reducing the health-related quality of life. Radiofrequency catheter ablation (CA) became the therapy of choice in patients with drug-resistant AF with success rates between 30% and 86%. However, CA remains a challenging intervention with major complications in about 5% of cases. Therefore, stratification into high and low success patient groups would be helpful. The aim of this study was to investigate the predictive value of B-type natriuretic peptide (BNP) on the outcome of pulmonary vein isolation (PVI) in patients with paroxysmal (PAF) and persistent (Pers-AF) atrial fibrillation. MATERIALS AND METHODS: In 73 patients (median age 53 years, 77% men) undergoing PVI for drug-refractory PAF (n = 45) or Pers-AF (n = 28), the serum BNP concentration was measured before and 3 months after the ablation procedure to assess any association of pre- and post-interventional BNP concentrations with therapeutic outcome. The patients had suffered from AF for a median of 40 months. No patient had structural heart disease or an impaired left-ventricular ejection fraction. RESULTS: A total of 54 patients (74%) had stable sinus rhythm 3 months after PVI. The median baseline BNP levels in both PAF and Pers-AF patients were significantly lower in patients with a 3-month successful PVI than those in which it was unsuccessful, 57.5 pg/ml (20.4-87.9) versus 159.0 pg/ml (124.1-177.5; p = 0.001) in PAF patients and 90.3 pg/ml (41.0-155.0) versus 176 pg/ml (89.6-297.4; p = 0.026) in patients with Pers-AF, respectively. A multiple logistic regression analysis identified pre-interventional BNP levels as the only independent predictor for 3-month PVI outcomes (p = 0.010). Nevertheless, in this study, the predictive value of BNP for PVI outcomes was not high enough to permit individual outcome prediction. After successful PVI, BNP levels were significantly lower in patients with PAF and Pers-AF (median changes -16.9 and -23.8 pg/ml; p = 0.010 and p = 0.022, respectively), but not in patients with AF in follow-up (median change 9.0 pg/ml and -29.6 pg/ml; p = 1.000 and p = 0.109, respectively). CONCLUSION: Pre-ablation BNP level seems to be an independent marker for successful PVI procedures in patients with paroxysmal and persistent AF; however, the observed level of association is moderate.

Multidetector CT urography: experimental analysis of radiation dose reduction in an animal model.

The purpose of this study was to evaluate the possibility of reducing X-ray exposure during multidetector CT urography (MDCTU) considering image quality using a porcine model. MDCTU was performed in eight healthy pigs. Scanning was conducted using a gradual reduction of the tube current-time product at 120 kV [200-20 mAs (eff.) in ten steps]. Three blinded observers independently evaluated the image data for anatomic detail, subjective image quality, and subjective image noise. Overall image quality was compared to milliampere-second settings and radiation dose. Objective noise measurements were assessed. Noise measurements in patients were also performed to verify the comparabilty of the animal model. Adequate image quality allowing for detailed visualization of the upper urinary tract was obtained when the tube current-time product was decreased to 70 eff. mAs at 120 kV. Image noise did not impair image quality to a relevant degree using these parameters. There was high agreement among the observers (ICC = 0.95). In the animal experiments, reduced-dose MDCTU produced good image quality. A maximum current-time product reduction to 70 eff. mAs at 120 kV (CTDI(vol) = 5.3 mGy) proved to be feasible, thereby offering an advantageous dosage reduction. The study provides a basis for the development of reduced-dose MDCTU protocols in humans.

Value of T2-weighted, first-pass and delayed enhancement, and cine CMR to differentiate between acute and chronic myocardial infarction.

The aim of this study was to analyze the diagnostic accuracy of edema on T2-weighted (T2w) cardiac magnetic resonance imaging (CMR), presence of microvascular obstruction (MO) on first-pass enhancement (FPE) or on delayed enhancement (DE) CMR, and wall thinning on cine CMR to differentiate between acute (AMI) and chronic myocardial infarction (CMI) in patients with infarction on DE-CMR. Fifty patients were imaged 5 +/- 3 days (baseline) and 8 +/- 3 months (follow-up) after AMI at 1.5 T. Imaging findings were graded as present or absent in a blinded consensus reading. Edema was present at baseline in 48 (96%) patients and absent at follow-up in 49 (98%) patients. At baseline, MO was present in 29 (58%) patients on FPE-CMR and in 24 (48%) patients on DE-CMR (P = ns). At follow-up, persisting hypoenhancement was observed in ten (20%) patients on FPE-CMR, whereas two (4%) patients showed persisting hypoenhancement on DE-CMR (P<0.05). Wall thinning was present in 4 (8%) patients at baseline and in 20 (40%) patients at follow-up. Edema had high sensitivity (96%), specificity (98%), and accuracy (97%) to differentiate between AMI and CMI. Accuracy of all other imaging findings was lower compared to that of edema (P<0.001). In the presence of infarction on DE-CMR, T2w-CMR reliably differentiates between AMI and CMI.

MRI of the coronary vessel wall at 3 T: comparison of radial and cartesian k-space sampling.

OBJECTIVE: The purpose of our study was to compare the quality of 3D gradient-echo images obtained using radial versus cartesian k-space sampling at 3 T. CONCLUSION: This study shows that the quality of coronary vessel wall imaging of the right coronary artery with radial k-space sampling in 3D turbo field-echo sequences is superior to cartesian k-space sampling at 3 T. Radial k-space sampling at 3 T makes it possible to combine low motion artifact susceptibility with high signal-to-noise ratio.

Characterization of the peri-infarction zone using T2-weighted MRI and delayed-enhancement MRI in patients with acute myocardial infarction.

To characterize the peri-infarction zone using T2-weighted (T2w) magnetic resonance imaging (MRI) and infarct size on delayed enhancement (DE) MRI in patients with acute myocardial infarction (AMI). In 65 patients, short-axis T2w and DE MRI images were acquired 5 +/- 3 d after AMI. The MRI was analyzed using a threshold method defining infarct size on DE MRI and edema on T2w MRI as areas with signal intensity larger than +2 SD above remote normal myocardium. The peri-infarction zone was calculated as the difference between the size of edema and the infarct size. The size of edema on T2w MRI (31.3 +/- 13.4% of LV area) was larger than the infarct size on DE MRI (20.3 +/- 10.4% of LV area, p< 0.0001). The size of the peri-infarction zone was 11.0 +/- 10.0% of the LV area. Good correlation was found between infarct size on DE MRI and peak creatine kinase (CK) isoenzyme MB (r = 0.65, p< 0.0001), but there was no correlation between the size of the peri-infarction zone and CK MB (r = 0.05, p = 0.67). The peri-infarction zone was larger in patients with an infarct size <28% of the LV area (12.6 +/- 10.0% LV area) compared with patients with an infarct size > or =28% of the LV area (6.7 +/- 9.0% of the LV area, p< 0.05). The peri-infarction zone does not correlate with enzymatic parameters of infarct size and is substantially larger in small infarcts, indicating viable myocardium.