The association of baseline left atrial structure and function measured with cardiac magnetic resonance and pulmonary vein isolation outcome in patients with drug-refractory atrial fibrillation.

Prognostic significance of left atrial (LA) function in patients with atrial fibrillation (AF) is poorly defined. To examine the association of LA function measured with cardiac magnetic resonance (CMR) feature-tracking and AF recurrence following catheter ablation. One hundred and twenty-one AF patients (72% paroxysmal, mean age 59 ± 10 years) were enrolled. Baseline LA function was measured by calculating passive, active, and total emptying fractions (LAEF) and analysis of global longitudinal strain and strain rates. Patients were followed up for recurrence of AF or atrial tachycardia (AT). Hazard ratios for recurrence were calculated using Cox proportional models adjusted for potential clinical confounders, type of AF, left ventricular ejection fraction, AF duration, LA volume, and late gadolinium enhancement (LGE). During a mean follow-up of 18 ± 9 months, 52 patients (43%) experienced recurrent AF/AT. Patients with recurrent AF/AT had higher baseline LA volume index and lower LA passive, and total LAEF (P < .05 for all). The baseline peak LA strain and strain rates in all phases of LA function were lower in the AF/AT recurrence group (P < .01 for all). In multivariable analysis total LAEF, peak LA strain, and systolic and late diastolic strain rates were associated with recurrence. Both peak LA strain and total LAEF improved prediction of recurrent AT/AF compared to the baseline clinical model, including LA LGE (C statistic 0.82 vs 0.77, P < .05 for both total LAEF and peak LA strain). LA reservoir function was independently associated with recurrent AF/AT after PVI and can additionally improve risk stratification in patients undergoing PVI.

Habibi M ，Lima JAC ，Gucuk Ipek E ，Zimmerman SL ，Zipunnikov V ，Spragg D ，Ashikaga H ，Rickard J ，Marine JE ，Berger RD ，Calkins H ，Nazarian S ... -  《-》

A comprehensive multi-index cardiac magnetic resonance-guided assessment of atrial fibrillation substrate prior to ablation: Prediction of long-term outcomes.

Multiple cardiac magnetic resonance (CMR)-derived indices of atrial fibrillation (AF) substrate have been shown in isolation to predict long-term outcome following catheter ablation. Left atrial (LA) fibrosis, LA volume, LA ejection fraction (EF), left ventricular ejection fraction (LVEF), LA shape (sphericity) and pulmonary vein anatomy have all been shown to correlate with late AF recurrence. This study aimed to validate and assess the relative contribution of multiple indices in a long-term single-center study. Eighty-nine patients (53% paroxysmal AF, 73% male) underwent comprehensive CMR study before first-time AF ablation (median follow-up 726 days [IQR: 418-1010 days]). The 3D late gadolinium-enhanced acquisition (1.5T, 1.3 × 1.3 × 2 mm) was quantified for fibrosis; LA volume and sphericity were assessed on manual segmentation at atrial diastole; LAEF and LVEF were quantified on multislice cine imaging. AF recurred in 43 patients (48%) overall (31 at 1 year). In the recurrence group, LA fibrosis was higher (42% vs 29%; hazard ratio [HR]: 1.032; P = .002), left atrial ejection fraction (LAEF) lower (25% vs 34%; HR: 0.063; P = .016) and LVEF lower (57% vs 63%; HR: 0.011; P = .008). LA volume (135 vs 124 mL) and sphericity (0.819 vs 0.822) were similar. Multivariate Cox regression analysis was adjusted for age and sex (Model 1), additionally AF type (Model 2) and combined (Model 3). In Models 1 and 2, LA fibrosis, LAEF, and LVEF were independently associated with outcome, but only LA fibrosis was independent in Model 3 (HR: 1.021; P = .022). LAEF, LVEF, and LA fibrosis differed significantly in the AF recurrence cohort. However, on combined multivariate analysis only LA fibrosis remained independently associated with outcome.

Chubb H ，Karim R ，Mukherjee R ，Williams SE ，Whitaker J ，Harrison J ，Niederer SA ，Staab W ，Gill J ，Schaeffter T ，Wright M ，O'Neill M ，Razavi R ... -  《-》

Association of left atrial function and left atrial enhancement in patients with atrial fibrillation: cardiac magnetic resonance study.

Atrial fibrillation (AF) is associated with left atrial (LA) structural and functional changes. Cardiac magnetic resonance late gadolinium enhancement (LGE) and feature-tracking are capable of noninvasive quantification of LA fibrosis and myocardial motion, respectively. We sought to examine the association of phasic LA function with LA enhancement in patients with AF. LA structure and function was measured in 90 patients with AF (age 61±10 years; 76% men) referred for ablation and 14 healthy volunteers. Peak global longitudinal LA strain, LA systolic strain rate, and early and late diastolic strain rates were measured using cine-cardiac magnetic resonance images acquired during sinus rhythm. The degree of LGE was quantified. Compared with patients with paroxysmal AF (60% of cohort), those with persistent AF had larger maximum LA volume index (56±17 versus 49±13 mL/m(2); P=0.036), and increased LGE (27.1±11.7% versus 36.8±14.8%; P<0.001). Aside from LA active emptying fraction, all LA parameters (passive emptying fraction, peak global longitudinal LA strain, systolic strain rate, early diastolic strain rate, and late diastolic strain rate) were lower in patients with persistent AF (P<0.05 for all). Healthy volunteers had less LGE and higher LA functional parameters compared with patients with AF (P<0.05 for all). In multivariable analysis, increased LGE was associated with lower LA passive emptying fraction, peak global longitudinal LA strain, systolic strain rate, early diastolic strain rate, and late diastolic strain rate (P<0.05 for all). Increased LA enhancement is associated with decreased LA reservoir, conduit, and booster pump functions. Phasic measurement of LA function using feature-tracking cardiac magnetic resonance may add important information about the physiological importance of LA fibrosis.

Habibi M ，Lima JA ，Khurram IM ，Zimmerman SL ，Zipunnikov V ，Fukumoto K ，Spragg D ，Ashikaga H ，Rickard J ，Marine JE ，Calkins H ，Nazarian S ... -  《-》

Incremental Value of Left Atrial Geometric Remodeling in Predicting Late Atrial Fibrillation Recurrence After Pulmonary Vein Isolation: A Cardiovascular Magnetic Resonance Study.

Nakamori S ，Ngo LH ，Tugal D ，Manning WJ ，Nezafat R ... -  《Journal of the American Heart Association》

Left atrial passive emptying function determined by cardiac magnetic resonance predicts atrial fibrillation recurrence after pulmonary vein isolation.

Although pulmonary vein isolation has become a mainstream therapy for selected patients with atrial fibrillation (AF), late recurrent AF is common and its risk factors remain poorly defined. The purpose of our study was to test the hypothesis that reduced left atrial passive emptying function (LAPEF) as determined by cardiac magnetic resonance has a strong association with late recurrent AF after pulmonary vein isolation. Three hundred forty-six patients with AF referred for cardiac magnetic resonance pulmonary vein mapping before pulmonary vein isolation were included. Maximum LA volumes (VOLmax) and volumes before atrial contraction (VOLbac) were measured; LAPEF was calculated as (VOLmax-VOLbac)/VOLmax×100. Kaplan-Meier curves were constructed to determine late recurrent AF stratified by LAPEF quintile. Cox proportional hazards regression was used to adjust for known markers of recurrence. During a median follow-up of 27 months, 124 patients (35.8%) experienced late recurrent AF. Patients with recurrence were more likely to have nonparoxysmal AF (75.8% versus 51.4%; P<0.01), higher mean VOLmax (60.2 versus 52.8 mL/m(2); P<0.01), and lower mean LAPEF (19.1% versus 26.0%; P<0.01). Patients in the lowest LAPEF quintile were at highest risk of developing recurrent AF (2-year recurrence for lowest versus highest: 60.5% versus 17.3%; P<0.01). After adjusting for known predictors of recurrence, patients with low LAPEF remained significantly more likely to recur (hazard ratio for lowest versus highest quintile, 3.92; 95% confidence interval, 2.01-7.65). We found a strong association between LAPEF and recurrent AF after pulmonary vein isolation that persisted after multivariable adjustment.

Dodson JA ，Neilan TG ，Shah RV ，Farhad H ，Blankstein R ，Steigner M ，Michaud GF ，John R ，Abbasi SA ，Jerosch-Herold M ，Kwong RY ... -  《-》