The purpose of this study is to evaluate the safety and potential benefits of the interatrial septal defect (IASD) System in patients with heart failure with preserved ejection fraction.

The study was a multi-center, non-randomized feasibility evaluation of the IASD System at three centers in three countries (Denmark, Australia, and Czech Republic). Relevant ethics committee and competent authority approvals were obtained. The study was conducted in accordance with the Declaration of Helsinki. The protocol required the treatment of a minimum of 5 patients, and allowed up to twenty patients to be enrolled.

The primary objective of the trial was to evaluate the safety and potential benefits of the IASD Device System in the treatment of patients with symptomatic heart failure with preserved ejection fraction, despite optimal medical management.

Inclusion Criteria:

• Clinical diagnosis of HFpEF
• Ejection Fraction of at least 45%
• Imaging and hemodynamic evidence of HFpEF
• History of exercise intolerance
• Symptomatic despite optimal medical management
• Signed study specific informed consent

Exclusion Criteria:

• History of thromboembolic events
• Significant structural heart disease or coronary artery disease
• Contraindicated to study required medication
• Right ventricular dysfunction
• History of greater than mild restrictive or obstructive lung disease
• Life expectancy less than one year for non-cardiovascular reasons
• Known or suspected allergy to implant material
• Fertile women