The anatomic impact of sequential, additional, ostial radiofrequency ablation following pulmonary vein cryo-isolation.

BACKGROUND: Although pulmonary vein (PV) stenosis is a serious complication of radiofrequency PV isolation, the anatomical impact of a combination of two energy sources on PV diameter has not been evaluated. The aim of this study was to evaluate the impact of supplementary point-by-point radiofrequency applications (following PV cryoablation) on the PV orifice diameter. METHODS: Forty-nine patients having undergone PV isolation for drug-refractory atrial fibrillation were included. All had undergone cardiac computed tomography before ablation and again at least 3 months afterwards. When isolation with the cryoballoon was not complete, a conventional irrigated-tip radiofrequency catheter was used for point-by-point applications. RESULTS: Of the 189 target PVs, 117 were isolated with cryotherapy alone (cryo PVs) and 72 required additional radiofrequency (hybrid PVs). The second scan (performed an average of 11.4 ± 5.4 months after) showed a decrease in diameter for all the hybrid PVs (17.2 ± 2.6 to 16.3 ± 3.4 mm; P = 0.037) but no change for the cryo PVs. This change was associated with a decrease in left superior pulmonary vein (LSPV) diameter (19.2 ± 3.0 to 17.8 ± 4.9 mm, P = 0.014). There were no changes in other veins. A subgroup analysis for the LSPV revealed a decrease for the hybrid PVs (18.8 ± 3.6 to 15.9 ± 7.1 mm, P = 0.046) but not for the cryo PVs. Significant PV stenosis was observed in three hybrid PVs (two severe stenosis of the LSPV and one moderate stenosis of the right inferior pulmonary vein) but not in cryo PVs (4.1% vs 0%, respectively; P = 0.023). CONCLUSIONS: Cryoballoon ablation of the PV with adjunct, focal, irrigated ostial RF applications may be associated with a higher risk of PV stenosis.

Dual balloon size strategy for cryoisolation of the pulmonary veins in patients with atrial fibrillation: comparison of 23 and 28mm diameter cryoballoons.

BACKGROUND: Systematic use of a 28mm balloon has been proposed for pulmonary vein cryoisolation in patients with atrial fibrillation. OBJECTIVE: To assess the results of a dual balloon size strategy using a 23 or 28mm cryoballoon catheter for pulmonary vein isolation. METHODS: A total of 118 patients (mean age 56 ± 10 years) with paroxysmal (n=85) or persistent atrial fibrillation (n=33) were enrolled. Patients with four pulmonary veins<20mm in diameter were isolated with a 23mm cryoballoon (n=29); patients with one pulmonary vein diameter ≥20mm were isolated with a 28mm cryoballoon (n=89). RESULTS: No significant difference in procedural variables was observed between the two groups. AF-free survival, after a mean follow-up of 19.9 ± 5 months, was similar in the two groups (69% vs 62%; p=0.57 and between patients with paroxysmal atrial fibrillation (68% vs 68%; p=0.91) or persistent AF (75% vs 48%; p=0.60). AF duration before the ablation procedure (p=0.005) was an independent predictor of AF recurrence. Phrenic nerve palsy rate was not statistically different in the two groups (4 [14%] vs 9 [10%]; p=0.73). The temperature in the right superior pulmonary vein (p=0.008) was an independent predictor of phrenic nerve palsy. Five patients developed left atrial flutter with the 28mm diameter balloon versus none with the 23mm balloon. CONCLUSIONS: A dual balloon size strategy was not associated with a lower AF-free survival or a higher procedure-related complication rate in patients in whom the 23mm balloon was used. Pulmonary vein isolation with a 23mm cryoballoon catheter appears to be an appropriate option in selected patients with small pulmonary vein diameters.

Intraaortic pulse pressure amplification in subjects at high coronary risk.

Peripheral (brachial) pulse pressure normally exceeds central (aortic) pulse pressure but is a less powerful predictor of cardiovascular risk. The difference between the 2 variables, called pulse pressure amplification, has never been specifically studied between the proximal and distal aorta in coronary patients. Our goal was to determine aortic pulse pressure amplification in subjects at high coronary risk, with emphasis on associated renal and inflammatory factors. Blood pressure was measured invasively in the ascending aorta, abdominal aorta (at the level of kidneys), and iliac artery in 101 subjects (mean age, 63+/-11 years; 61 men) undergoing coronary angiography. Independently of age, sex, and the presence of coronary stenosis, the increase of pulse pressure between the ascending and terminal aorta was over 10 mm Hg (P<0.001), whereas mean blood pressure remained unchanged. Pulse pressure amplification did not differ significantly between patients with and without coronary artery stenosis. Irrespective of confounding variables, high pulse pressure measured in the ascending aorta and at the level of renal arteries (but not in the iliac artery) was independently related to proteinuria. The increase in pulse pressure from the ascending aorta to the renal level was negatively associated with leukocyte count, even after multivariate adjustment (beta coefficient, -0.19; 95% CI, -0.39 to 0.0; P<0.05). Increased plasma creatinine and aortic pulse wave velocity were independently and positively correlated (beta coefficient, 0.36; CI, 0.18 to 0.54; P<0.001). Independently of coronary atherosclerosis, aortic pulse pressure integrates the predictive value of aortic, inflammatory, and renal factors.