Noninvasive Leg-Positive Pressure Stress Echocardiography Reveals Preload Reserve in Adult Patients after Complete Repair of Tetralogy of Fallot

Easy-to-use preload stress echocardiography by using combined dynamic postural stress can identify high-risk patients with heart failure with reduced ejection fraction

Aims

Haemodynamic assessment during stress testing is not commonly performed in patients with heart failure with reduced ejection fraction (HFrEF) because of its invasiveness, lower feasibility, and safety concerns. This study aimed to assess the haemodynamic characteristics of patients with HFrEF in response to non‐invasive preload stress during dynamic postural alterations achieved by combining both semi‐sitting position and passive leg‐lifting and to evaluate whether combined postural stress could be used for risk stratification in these patients.

Methods and results

For this study, 101 patients with HFrEF and 35 age‐matched and sex‐matched healthy controls were prospectively recruited. After all standard echocardiographic measurements were obtained in the left decubitus position, all subjects underwent postural stress testing, which consisted of changing from semi‐sitting position to passive leg‐lifting. During a median follow‐up period of 12.2 months, 21 (21%) patients developed adverse cardiovascular events. In patients without adverse cardiovascular events, the stroke volume index (SVi) significantly changed from 28 ± 8 to 35 ± 10 mL/m² (P < 0.001) during combined postural stress. By contrast, ΔSVi during combined dynamic postural stress was significantly smaller in patients with cardiovascular events than in those without events (ΔSVi 3.4 ± 4.0 vs. 6.4 ± 3.8 mL/m², P = 0.002), which indicated severely diseased heart operated on a relatively flat portion of the Frank–Starling curve. In a multivariate Cox proportional hazard analysis, ΔSVi (hazard ratio 0.81, P = 0.02) was an independent predictor of future adverse cardiovascular events.

Conclusions

The combined assessment of dynamic postural stress is a non‐invasive, simple, quick, and easy‐to‐use clinical tool for assessing preload reserve and risk stratification in HFrEF patients.