Latent heart failure could be unmasked during exercise. Left atrial (LA) remodeling reflects the cumulative effects of left ventricular (LV) filling pressure over time and is usually determined by measurement of the LA volume indexed to body surface area (LAVi). We hypothesized that an indexation of the LA volume to the LV volume (LA/LV) would be more sensitive to detect abnormal exercise LV filling pressure as an index of early-stage heart failure with preserved ejection fraction (HFpEF)

To assess the value of the LA/LV ratio to detect abnormal exercise LVEDP in patients with preserved LV ejection fraction (LVEF) and to investigate its association with maximal exercise capacity in two different cohorts.

We invasively measured LVEDP at rest and during low-level exercise in 45 patients with LVEF>50% and normal resting LVEDP (LVEDP≤16mmHg). Correlations and receiver operator characteristic (ROC) curves were used to evaluate the association of LA/LV and LAVi with resting LVEDP, exercise LVEDP and ΔLVEDP (exercise LVEDP–resting LVEDP). The association of LA size indices with maximal exercise capacity during exercise echocardiography was also evaluated in 207 other patients.

In the invasive study, 27 out of 45 patients had abnormal LV filling pressures during exercise. LA/LV and LAVi were not correlated to resting LVEDP. Among the two, only LA/LV was significantly correlated to exercise LVEDP (r=0.42, P=0.004), ΔLVEDP (r=0.39, P=0.007), and had a significant diagnostic value to detect early-stage HFpEF (area under the ROC curve 0.74, P=0.007). In the non-invasive study, LA/LV was significantly associated with exercise capacity in multivariate analysis (β=−0.153, P=0.012) while LAVi was not in a similar model.

The relative expansion of the LA over the LV as an early sign of heart remodeling appears more valuable than the conventional LAVi to detect early-stage HFpEF.