Abstract 13086: Left Atrial Function in Adult With Normally Functioning Bicuspid Aortic Valves

Background: Bicuspid aortic valve is a complicated and heterogeneous disease that has aroused great interest in recent years. Traditionally the greatest attention during a routine echocardiography is paid to the function of the ventricles and aortopathy, much less is known about dysfunction the left atrium. The objective of this study was to characterize left atrial strain (LAS) and functions by two-dimensional speckle tracking echocardiography in adult BAV with normally functioning, and interrogate the risk factors. Methods: This is a prospective cohort study of 52 patients (age 40.23±11.29 years) and 33 healthy volunteers (aged 39.12±12.74 years) were recruited. All subjects included in both groups were in sinus rhythm and no clinical history of cardiovascular diseases. We mainly assessed left atrial reservoir, pump, and conduit function using 2D STE, then determined relationships among indices of segmental aortic stiffening, BAV cusp fusion pattern, LV diastolic function indices and LA deformation. Results: Without adjustment, the indices of LA functions in patients with BAV were significantly decreased compared with controls (LAS 49.41 ± 11.14 vs 59.48 ± 9.53, p<0.001, LAEF 71.56 ± 6.57 vs 76.36 ± 5.72, p=0.001; LAS-passive 29.43 ± 9.42 vs 36.67 ± 9.60, p=0.001, LAEF-passive 43.72 ± 10.78 vs 49.58 ± 6.80, p=0.003). However, after adjustment on age, gender, systolic blood pressure, diastolic blood pressure, BSA ,only the LAS was lowering (p<0.001). With or without adjustment, the ascending aorta of patients with BAV were still stiffer at each segment compared with controls. As parameters of LV diastolic functions, the E/e’ ratio (p=0.01) and e’ value (p=0.01) were significantly altered. The LA volume were increased in BAV patients (59.33 ± 19.12 vs 46.10 ± 9.73). In patients with BAV, LA functions, LV functions and segmental aortic stiffness were not influenced by the Sivere valve types. In multiple regression analysis, the stiffness at the sinus of Valsalva were independently correlated with LAS (adjust R 2 = 0.82, β = -0.33, p<0.001). Conclusion: Left atrial dysfunction is common in adult BAV with normally functioning. LA dysfunction is associated with stiffness index at the sinus of Valsalva, and is independent of LV function.

Abstract 16854: Left Atrial Dysfunction and Prediction of Atrial Fibrillation in LMNA Cardiomyopathy

Introduction: LMNA cardiomyopathy is characterized by a high incidence of atrial fibrillation (AF) and an increased risk for AF-related stroke. AF commonly occurs before apparent cardiomyopathy, and the ability to predict its incidence in asymptomatic LMNA mutation carriers is limited. We sought to evaluate the presence of echocardiographic features specific to LMNA and whether they predict AF incidence. Methods: Patients harboring LMNA mutations (n=77) from two referrals centers between 2000 and 2017 were retrospectively included. Comparator groups included patients with TTN cardiomyopathy (n=35) and healthy subjects (n=36). Echocardiograms at first clinical contact were analyzed for routine metrics and LA strain and related to incident AF. Results: Patients with LMNA mutations were assessed at median age 47 years (IQR, 32-62) with median LVEF 51% (41-61). In LMNA patients with LVEF ≥55% (n=20) and healthy subjects matched for LVEF, LA contractile strain was lower in LMNA patients (-10% vs -16%, respectively; P = 0.047), whereas other parameters did not significantly differ (Figure, panel A). Comparison of LVEF-matched LMNA and TTN cardiomyopathy patients showed LA contractile strain as the only distinguishing feature (-5.8% vs -12.8%, respectively; P = 0.01) (Figure, panel B). LMNA patients without previous AF (n=35) were followed for a total of 133 patient-years during which 11 (31%) developed AF. In Cox regressions adjusted for clinical and echocardiographic variables, decreased LA contractile strain (<

Increased remote extracellular volume measured by CMR T1 mapping allows early identification of left atrial dysfunction in hypertrophic cardiomyopathy

Background Myocardial fibrosis is a hallmark of hypertrophic cardiomyopathy (HCM). Cardiac magnetic resonance (CMR) detects replacement fibrosis (RF) through late gadolinium enhancement (LGE) and interstitial fibrosis (IF) in apparently unscarred myocardium by T1 mapping-derived increased extracellular volume (ECV). Differently from LGE, to date only few small studies have explored the clinical significance of IF in HCM and a correlation between IF and diastolic dysfunction (DD) has been proposed. However, DD detection is challenging in this population since the accuracy of standard echocardiographic parameters is controversial, especially in presence of left ventricular outflow tract obstruction (LVOTO). Left atrial (LA) dysfunction is associated with high left ventricular (LV) filling pressures and may represent an early marker of DD in HCM. Purpose To explore the correlation between IF and LA dysfunction in HCM patients with preserved systolic function. Methods 93 consecutive HCM patients with preserved EF underwent a standard CMR scan. Semi-automatic threshold-based quantification of ventricular volumes, function and mass was performed. LA volumes (LAV) and function were evaluated by CMR feature-tracking (FT) analysis. The three atrial phasic functions were analyzed: (i) passive strain (εe), (ii) active strain (εa) and (iii) total strain (εs). LGE was quantified using the standard deviations (SDs) method (≥4 SDs). IF was assessed by T1 mapping-derived ECV quantification in remote myocardium (r-ECV). A matched group of 15 healthy subjects (HS) served as controls. Results Compared to HS, HCM patients showed increased LAV (LAV max: HS 39±9ml, HCM 59±20 ml; LAV min: HS 16±4 ml, HCM 34±17 ml; p&lt;0.001), reduced LA EF (HS 61±3%, HCM 45±12%, p&lt;0.001), impaired εs (HS 40±7%, HCM 29±11%, p&lt;0.001) and εe (HS 26±7%, HCM 15±7%, p&lt;0.001). No differences in εa were observed (HS 13±4%, HCM 14±7%, p 0.56). HCM patients were divided into 2 groups according to the presence of IF, defined as r-ECV values ≥29%. The two ECV groups did not differ in terms of LV EF, LA EF, LAV, LA area, E/E', LGE, LV mass, maximal wall thickness and LVOTO (all p&gt;0.05). HCM patients with increased r-ECV showed significantly impaired LA function in terms of all three strain parameters vs. normal r-ECV group (HCM r-ECV &lt;29%: εs 31±12%, εe15±7%, εa 15±5%; HCM r-ECV≥29%: εs 24±7%, εe 12±4%, εa 12±5%; all p&lt;0.05). Conclusions In HCM patients increased r-ECV correlates with LA dysfunction, hinting towards a possible role for IF in determining altered LV relaxation and DD. LA strain in controls and HCM ECV groups Funding Acknowledgement Type of funding source: None