Prevalence, Patterns, and Clinical Predictors of Left Ventricular Late Gadolinium Enhancement in Patients Undergoing Cardiac Magnetic Resonance Prior to Pulmonary Vein Antral Isolation for Atrial Fibrillation

Cardiac magnetic resonance (CMR) imaging is increasingly used to evaluate patients with atrial fibrillation (AF) before pulmonary vein antral isolation (PVAI). The purpose of this study was to assess the incidence and pattern of left ventricular (LV) late gadolinium enhancement (LGE) in patients undergoing CMR before PVAI and compare the clinical and demographic differences of patients with and without LV LGE. Clinical and demographic data on 62 patients (mean age 61 7.9, 69% male) undergoing CMR before PVAI for AF were collected. Two observers, masked to clinical histories, independently recorded the prevalence, extent (number of myocardial segments), and pattern (subendocardial, midmyocardial, or subepicardial) of LV LGE in each patient. Clinical and demographic predictors of LV LGE were determined using logistic regression. Twenty-three patients (37%) demonstrated LV LGE affecting a mean of 3.0 2.1 myocardial segments. There was no difference in LV ejection fraction between patients with and without LGE, and most (65%) patients with LGE had normal wall motion. Only age (P1⁄4 0.04) and a history of congestive heart failure (P1⁄4 .03) were statistically significant independent predictors of LGE. The most common LGE pattern was midmyocardial, seen in 17 of 23 (74%) patients. Only 4 of 23 (17%) patients had LGE in an ‘‘expected’’ pattern based on clinical history. Of the remaining 19 patients, 4 had known congestive heart failure, 5 nonischemic cardiomyopathy, 4 known coronary artery dis, Saman Nazarian, e DeWire, fan L. Zimmerman, MD undergoing CMR before PVAI for AF, with most patients demonstrating a nonischemic pattern of LV LGE and no wall motion abnormalities (ie, subclinical disease). The high prevalence of unexpected LGE in these patients may argue for CMR as the modality of choice for imaging integration before PVAI, especially given the demonstrated prognostic value of LGE in this and other patient populations. (Medicine 94(37):e1384) Abbreviations: AF = atrial fibrillation, CMR = cardiac magnetic resonance, LGE = late gadolinium enhancement, LV = left ventricular, LVEF = left ventricular ejection fraction, PVAI = pulmonary vein antral isolation, WMA = wall motion abnormality. INTRODUCTION A trial fibrillation (AF) is a common clinical problem, affecting an estimated 2.3 million adults in the United States in 2011, with a projected rise in prevalence to 5.6 million by the year 2050. Pulmonary vein antral isolation (PVAI) via endovascular catheter ablation has been validated as an effective therapy for symptomatic AF, with evidence supporting the procedure both in patients refractory to/intolerant of antiarrhythmic medications and in select patients before the initiation of medical antiarrhythmic therapy. Although PVAI can be performed with only standard electroanatomic mapping systems, image integration using computed tomography, cardiac magnetic resonance imaging (CMR), intracardiac ultrasound, and fluoroscopic angiography is available and may increase the safety and efficacy of the procedure. Most major centers, clinical trials, and registries utilize some form of imaging; however, there is currently no consensus on the optimal modality. CMR can accurately map cardiac and pulmonary venous morphology without exposing patients to ionizing radiation. In addition, left ventricular functional analysis on dynamic CMR and late gadolinium enhancement (LGE) on gadolinium-enhanced CMR provides ancillary information that has demonstrated prognostic value in a variety of patient populations. and may have value in appropriate patient selection for PVAI. There are limited data suggesting that left ventricular (LV) LGE is more prevalent in patients with AF and Neilan et al recently demonstrated that LV LGE has strong prognostic value in this population. Accordingly, the purpose of the current study was to assess the incidence and a cohort of patients undergoing CMR are the demographic and clinical characth and without LV LGE. www.md-journal.com | 1 MATERIALS AND METHODS Patient Population The study was performed as a retrospective cross-sectional analysis using data from a larger, prospective study. The study protocol was approved by our Institutional Review Board and performed in accordance with HIPPA regulations. Inclusion criteria were all patients referred for PVAI for the treatment of symptomatic drug-refractory AF between July 19, 2011 and December 5, 2012; informed consent was obtained. Patients were excluded if they had contraindications to contrast-enhanced MRI (renal insufficiency as defined by an estimated glomerular filtration rate less than 60 mL/min, history of severe contrast allergy to contrast material, cardiac pacemaker, incompatible metallic implant). Sixty-eight consecutive patients were included who received CMR before PVAI between July 19, 2011 and December 5, 2012. Demographic and Clinical Data Demographic and clinical data were acquired via review of electronic medical records at the time of initial enrollment. In addition to basic demographic information, cardiac risk factors, clinical cardiac history, and AF history were recorded. AF was categorized as paroxysmal (AF self-termination within 7 days), persistent (AF lasting >7 days or requiring cardioversion), or long-standing persistent (AF lasting >1 year). CHADS2 scores were calculated for each patient. LV ejection fraction (LVEF) was recorded as determined by transthoracic echocardiography performed in standard fashion at the time of initial evaluation.