Contractile Reserve in Heart Failure with Preserved Ejection Fraction

Background: Diastolic stress echocardiography (SE) is useful for confirming the diagnosis of heart failure with preserved left ventricular ejection fraction (HFpEF) when it is uncertain. The aim of this study was to assess the value of new echocardiographic parameters during diastolic SE in patients with dyspnea and suspected HFpEF. Methods: Sixty-two patients with exertional dyspnea and inconclusive rest echocardiography for a diagnosis of HFpEF were enrolled. Exercise SE was performed in all patients. Contractile reserve (LVCR) was assessed by measuring: 1. changes in the left ventricular ejection fraction (LVEF) between rest and peak stress; 2. stress-to-rest ratio of force (force was defined as the ratio between systolic arterial pressure and left ventricular end-systolic volume); and 3. mechanical reserve, defined as the change in systolic strain (GLS) between rest and peak stress. Results: Diagnosis of HFpEF was performed by SE in 26 patients. Comparing patients with a diagnosis of HFpEF (group A) to patients with other causes of dyspnea (group B), we found a significant increase in the E/e' ratio in group A at peak stress. LV GLS was significantly reduced in group A compared to group B at rest and stress (p value 0.01 at rest; p value 0.04 at stress). At peak stress, GLS did not significantly increase in group A, while it increased in group B (p value 0.04). LVEF increased significantly in both groups. Conclusion: Patients with HFpEF have impaired LVCR when assessed using GLS. Thus, the assessment of mechanical reserve could give additional diagnostic information during stress tests in patients with HFpEF.