Heart failure with preserved ejection fraction (HPEF, defined as LVEF ≥50%) represents 50% of hospital admissions for heart failure. Although its morbi-mortality is similar to that of heart failure with reduced ejection fraction (HFPEF), it remains an unknown disease with limited data especially from an etiological point of view. The underlying causes are imperfectly understood, and more than half of the patients have HPEF labeled "idiopathic."

A non-hierarchical clustering study of HPEF patients led to the identification of a subgroup of patients (25%) with a predominant coronary vascular phenotype (i.e., a history of coronary stenosis with or without the need for revascularization). In these patients, vascular endothelial dysfunction would play a central role in the development and progression of heart failure.One of the mechanisms leading to HPEF could be a decrease in the bioavailability of nitric oxide (NO) involved in the relaxation of the cardiac muscle. As the mechanism of action of NO is pleiotropic, a decrease in NO bioavailability could also be observed at the peripheral level, favoring in the long term the development of unfavorable vascular remodeling, for example in the small digital or retinal arteries.Some HPEF patients could thus be distinguished from others by their predominant "vascular" profile. The link between HPEF and endothelial dysfunction has been suspected but never clearly demonstrated.

Ultra-high frequency ultrasound is an innovative technology to estimate the remodeling of small distal arteries in a non-invasive way. The investigators propose to use this imaging on digital arteries in HPEF patients and to study the association with known coronary macrovascular damage.The remodeling parameters will be measured and compared in patients with HPEF with or without identified macrovascular coronary disease.This characterization of arterial remodeling on the digital arteries could be a powerful tool for non-invasive screening in the identification of a subgroup of HPEF that is still considered idiopathic.

Inclusion Criteria :

Group 1 :

• Patients who are ≥ 18 years old
• Heart failure with preserved ejection fraction (LVEF ≥ 50%)
• B-type natriuretic peptide (BNP) > 35 pg/mL at inclusion
• Coronary macrovascular disease (significant coronary stenosis, which may have required revascularization by stenting or coronary bypass surgery).

Group 2 :

• Patients who are ≥ 18 years old
• Heart failure with preserved ejection fraction (LVEF ≥ 50%)
• B-type natriuretic peptide (BNP) > 35 pg/mL at screening
• Absence of coronary macrovascular disease (no significant coronary atheroma (< 30%) or history of stenting or coronary bypass surgery).

Non-inclusion Criteria :

Group 1 and group 2 :

• Patients under legal protection
• Patients not affiliated to a Social Security system
• Patient under State Medical Help (France - AME)
• Pregnancy or breastfeeding
• Refusal or inability to sign consent
• Known and treated retinal vasculopathy
• Severe or non-stabilized hypertension (BP > 180/100 mmHg at screening)
• History of LVEF < 40%.