B. Borlaug

Left Atrial Remodeling and Functional Maladaptations in Obesity: An Invasive Pressure-Volume Analysis.

BACKGROUND Obesity is a major risk factor for atrial fibrillation and heart failure. We aimed to characterize left atrial (LA) structural and functional changes across body mass index (BMI) strata in patients with atrial fibrillation referred for catheter ablation. METHODS We studied 1040 consecutive patients (67% male; mean age, 62 years; 71% in sinus rhythm). Participants were stratified by BMI (<25.0, 25-29.9, 30-34.9, and ≥35 kg/m2). Comprehensive echocardiographic assessment of LA structure and function was integrated with invasive LA pressure measurements obtained via transseptal access during the ablation procedure. Associations across BMI strata were evaluated using regression analyses. RESULTS Patients with higher BMI had larger estimated total blood and plasma volumes along with higher LA volumes and pressures, greater cyclic wall stress, and a rightward shift of the estimated LA pressure-volume relationship. Conversely, estimated operant LA stiffness did not differ across BMI strata. BMI-related differences in LA volume were attenuated by body surface area indexing but preserved with height-based indexing. Conventional volumetric indices of LA phasic function were similar across BMI strata, whereas available LA strain indices (n=107) were lower with greater adiposity, consistent with worse LA phasic function. Compared with patients without heart failure, those with heart failure exhibited more pronounced structural, functional, and hemodynamic atrial remodeling, consistent with a more advanced atrial myopathy phenotype. CONCLUSIONS In patients undergoing atrial fibrillation ablation, higher BMI is associated with a predominantly load-related pattern of LA remodeling, characterized by larger LA volume and pressures, greater cyclic wall stress, and a rightward shift of the estimated pressure-volume relationship. BMI-associated early atrial remodeling may precede overt atrial dysfunction, potentially contributing to the link between excess adiposity, atrial fibrillation, and heart failure with preserved ejection fraction.

Exercise stress echocardiography for diagnosis of heart failure with preserved ejection fraction: a multicentre study.

Cardiac mechanical efficiency in patients with cardiogenic shock.

BACKGROUND Cardiogenic shock (CS) is characterized by impaired left ventricular (LV) mechanical performance and adverse remodeling. We evaluated whether transthoracic echocardiography (TTE)-derived modified cardiac efficiency (mCE), integrating stroke work and residual LV volume, is associated with short- and long-term mortality in CS and whether its prognostic value differs by shock etiology. METHODS In this retrospective cohort study, consecutive adults admitted with CS to the cardiac intensive care unit at Mayo Clinic (2007-2018) were included if TTE was performed within 24 hours. mCE was calculated as (stroke volume × estimated LV end-systolic pressure) divided by LV end-systolic volume and categorized into quartiles. Primary outcome was in-hospital mortality; secondary outcome was 1-year mortality. Multivariable logistic and Cox models adjusted for illness severity, comorbidity burden, shock etiology, cardiac arrest, vasoactive therapy, and mechanical circulatory support. RESULTS Among 667 patients, median mCE was 48 mmHg (IQR 32-74). In-hospital mortality was 28% and increased stepwise across decreasing mCE quartiles. The lowest quartile had a 2.5-fold higher adjusted odds of in-hospital death (OR 2.53; 95%CI: 1.49-4.37; P < 0.001). One-year mortality was 41%; the lowest quartile had a twofold higher adjusted hazard of death (HR 2.05; 95%CI: 1.45-2.89; P < 0.001). Associations were stronger in acute coronary syndrome-related CS (interaction P = 0.035 for in-hospital; P = 0.015 for 1-year). Within the lowest quartile, reduced systolic pressure further amplified mortality risk. CONCLUSIONS Early TTE-derived mCE was independently associated with short- and long-term mortality in CS, particularly in acute coronary syndrome-related CS, and captured the interaction between ventricular remodeling and mechanical performance underlying high-risk phenotypes.