P5294Metabolically healthy obese is associated with better left atrial function and lower risk of adverse cardiovascular events including atrial fibrillation

Abstract

Abstract Purpose Metabolic syndrome (MetS) and obesity are both crucial risk factors for heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF). However, the prognostic value of utilizing left atrial (LA) deformation imaging in metabolically healthy obese (MHO) or metabolically unhealthy normal weight (MUNW) subjects remains largely unexplored. Methods Speckle-tracking echocardiography was used to evaluate LA strain and strain rate among 3,915 subjects free from clinical heart failure (mean age: 50.0±10.6 years, 66.2% male) undergoing annual cardiovascular health survey. Metabolically unhealthy was defined by the presence of at least one MetS component or history of cardiovascular disease. Participants were categorized as: metabolically healthy normal weight (MHNW), metabolically unhealthy normal weight (MUNW), metabolically healthy overweight/obese (MHO), metabolically unhealthy overweight/obese (MUO). Results Markedly decreased LA strain, early-diastolic LA strain rate and increased LA stiffness were observed with metabolic disorders (all trend p: <0.05). During a median follow-up period of 3.68 years, significantly higher risk of primary endpoints (death, heart failure, major cardiovascular events) was observed in MUO vs. MHO (HR=1.87, p=0.005) and MUNW vs. MHNW (HR=2.82, p=0.004). Similar patterns with incident AF (MUO vs MHO: HR=3.05, p=0.001, MUNW vs MHNW: HR=4.04, p=0.002) were also observed. After multivariate adjustment, risk of AF remained associated with low LA strain (β=−0.07, p<0.001), systolic LA strain rate (β:−0.05, p=0.007) and high LA stiffness (β=0.18, p<0.001). Comparison between metabolic groups MHNW (N=1107) MUNW (N=255) p (MUNW vs MHNW) MHO (N=1859) MUO (N=694) p (MUO vs MHO) Age 48±10.57 54.29±11.52 <0.001 49±10.02 54.21±10.49 <0.001 LA GLS (%) 40.6±7.68 37.16±7.5 <0.001 36.77±7.66* 33.58±8.01‡ <0.001 LA SRs 1.79±0.41 1.76±0.48 NS 1.63±0.39* 1.55±0.41‡ <0.001 LA SRe 2.11±0.62 1.8±0.63 <0.001 1.68±0.55* 1.48±0.52‡ <0.001 LA stiffness 0.17±0.08 0.22±0.12 <0.001 0.21±0.11* 0.25±0.13‡ <0.001 *p<0.001 for MHO vs MHNW, ‡p<0.001 for MUO vs MUNW. LA GLS = left atrial global longitudinal strain, LA SRs = left atrial systolic strain rate, LA SRe = left atrial early-diastolic strain rate, NS = non-significant. Kaplan-Meier curves of adverse events Conclusion Metabolic abnormality may contribute to certain aspects of mechanistic LA dysfunction tightly linked to clinical events, even with normal lean body mass. Our observations may be insightful for targeted interventions in higher-risk patients with subclinical atrial dysfunction.