Left Atrial Myopathy in Heart Failure with Preserved Ejection Fraction: Insights from the PROMIS-HFpEF Study

Background Impaired left atrial (LA) function in heart failure with preserved ejection fraction (HFpEF), defined by worse LA reservoir strain, is linked to adverse clinical outcomes. The characteristics of HFpEF patients who have LA myopathy out of proportion to left ventricular (LV) myopathy remain unclear. Methods In the Prevalence of Microvascular Dysfunction in HFpEF (PROMIS-HFpEF) study (n=241), we defined 3 phenotypes based on degree of LA myopathy (LA reservoir strain) compared with LV myopathy (global longitudinal strain) (Figure 1) and evaluated the associations between LA reservoir strain and 1) stroke volume (SV) response to leg lift and 2) coronary flow reserve (CFR). Results Patients with LA-predominant myopathy (n=42) were older and had a higher rate of atrial fibrillation (AF) compared with balanced LA/LV myopathy (n=151) and LA-preserved myopathy (n=48) (P Conclusion In HFpEF, there is a subgroup of patients with LA myopathy out of proportion to LV myopathy, highlighted by increased age and AF, along with lower SV, reduced SV reserve, and lower CFR. LA-predominant myopathy may serve as a future target for tailored HFpEF therapies.