Predictors of low voltage areas in persistent atrial fibrillation: is it really a matter of time?

BACKGROUND: Time has been postulated as an important factor for electrical remodeling of the left atrium (LA) in persistent atrial fibrillation (AF) ('AF begets AF'). However, it is still a matter of debate if structural changes are the cause or consequence of AF. We sought to determine the clinical and invasive parameters, which correlate with LA scar as determined by voltage mapping, in patients with persistent AF. METHODS: Seventy consecutive patients undergoing ablation of persistent (49%) or long-standing persistent AF (51%), between January 2013 and February 2014, were enrolled in the study. Besides clinical parameters, 2D echocardiographic assessment of LA size and LA pressure (LAP) after transseptal puncture was also considered. Bipolar endocardial signals with a mean voltage amplitude < 0.1 mV during AF were defined as LA scar. RESULTS: In the univariable analysis, LA scar was associated with age, gender, coronary artery disease (CAD), glomerular filtration rate (GFR), LA size and LAP. Arrhythmia duration, mild to moderate mitral regurgitation (MR), left ventricular dysfunction and left ventricular hypertrophy showed no significant correlation with atrial scar (all p > 0.05). In a multivariable regression model, LA scar area was independently associated with age, female gender and LA area. AF duration was not associated with LA scar. CONCLUSIONS: In this study, older age, greater LA area and female gender predicted the degree of LA scar, while other variables tested did not. In particular, we found no significant association between AF duration and LA scar.

Prognostic Impact of BNP Variations in Patients Admitted for Acute Decompensated Heart Failure with In-Hospital Worsening Renal Function.

BACKGROUND: The significance of worsening renal function (WRF) in patients admitted for acute decompensated heart failure (ADHF) is still controversial. We hypothesised that changes in brain natriuretic peptide (BNP) might identify patients with optimal diuretic responsiveness resulting in transient WRF, not negatively affecting the prognosis. Our aim was to verify if in-hospital trends of BNP might be helpful in the stratification of patients with WRF after treatment for ADHF. METHODS: 122 consecutive patients admitted for ADHF were enrolled. Brain natriuretic peptide and eGFR were evaluated at admission and discharge. A 20% relative decrease in eGFR defined WRF, whereas a BNP reduction ≥40% was considered significant. The primary combined endpoint was death/urgent heart transplantation and re-hospitalisation for ADHF. RESULTS: Worsening renal function occurred in 23% of patients without differences in outcome between patients with and without WRF (43% vs. 45%, p=0.597). A significant reduction in BNP levels over the hospitalisation occurred in 59% of the overall population and in 71% of patients with WRF. At a median follow-up of 13.0 (IQR 6-36) months, WRF patients with ≥40% BNP reduction had a lower rate of death/urgent heart transplantation/re-hospitalisation compared to WRF patients without BNP reduction (30% and 75%, respectively; p=0.007). Favourable BNP trend was the strongest variable in predicting the outcome in WRF patients (HR 0.222, 95% CI 0.066-0.753, p=0.016). CONCLUSIONS: Worsening renal function does not affect the prognosis of ADHF and, when associated with a significant BNP reduction, identifies patients with adequate decongestion at discharge and favourable outcome.

Catheter Ablation for "Lone" Atrial Fibrillation: Efficacy and Predictors of Recurrence.

BACKGROUND: Atrial fibrillation in otherwise healthy young patients has been termed "lone" atrial fibrillation (AF). The best treatment choice is still under discussion. The aim of this study was to report on efficacy and safety of catheter ablation. METHODS: Among 855 patients referred to our center between 2011 and 2013, 76 (9%) met the diagnostic criteria for lone AF (mean age 45 ± 8 years; mean LA diameter 37 ± 4 mm; paroxysmal AF 82%; persistent AF 18%). The primary endpoint was freedom from any atrial tachycardia after the first ablation; the secondary endpoint was freedom from any atrial tachycardia after the last ablation procedure without antiarrhythmic drugs. RESULTS: The primary endpoint occurred in 56 patients (74%) after a mean follow-up time of 444 ± 344 days. The secondary endpoint occurred in 73 patients (96%) after a mean of 1.3 ablations/patient during a follow-up time of 459 ± 366 days. The risk of AF recurrence was not influenced by AF duration or by the type of AF (paroxysmal versus persistent). In a multivariate regression analysis smoking (P = 0.001), first degree atrioventricular block (P = 0.001), and early (< 3 months) AF recurrence (P = 0.001) were independently associated with a higher risk of AF recurrence. Major peri-procedural adverse events did not occur. CONCLUSIONS: Catheter ablation in young healthy patients is highly effective and safe. The outcomes are maintained during long-term follow-up irrespective of preoperative AF duration. Patients with AF recurrence were more likely to smoke, have first degree AV block and early AF recurrence.

Impact of baseline atrial fibrillation cycle length on acute and long-term outcome of persistent atrial fibrillation ablation.

BACKGROUND: A short baseline atrial fibrillation (AF) cycle length (CL) has been associated with a worse outcome after catheter ablation for AF, whereas the impact of a long baseline AFCL is unknown. We investigated the influence of AFCL on acute and long-term success in a large series of patients undergoing catheter ablation for persistent AF. METHODS: Overall, 177 consecutive patients undergoing catheter ablation of persistent AF using a sequential ablation approach were included in the analysis. AFCL was measured in the left atrial appendage (LAA) at baseline and following each ablation step. The primary endpoint was freedom from any atrial arrhythmia off antiarrhythmic drugs (AAD) with a single ablation procedure after 12 months. RESULTS: Mean AFCL was 164 ± 24 ms. A shorter AFCL was associated with longer AF duration, larger LA diameter, and longer procedure duration. Termination to sinus rhythm (SR) was achieved in 57 (32 %) patients. Baseline AFCL was shorter (161 ± 24 ms) in patients without AF termination compared to patients with AF termination (169 ± 23 m, p = 0.03). The primary endpoint was reached less frequently in patients with a short (<155 ms) AFCL (18 vs. 38.5 %, p = 0.006). Patients with an AFCL between 155 and 200 ms had the best outcome compared to patients with AFCL <155 or ≥200 ms (40 vs. 18 %, p = 0.003). CONCLUSIONS: Patients with a baseline AFCL between 155 and 200 ms have the best outcome after a single ablation procedure for persistent AF compared to patients with an AFCL of <155 or ≥200 ms.