Background:

Heart failure with preserved ejection fraction (HFPEF) is common but not well understood. Electrical dyssynchrony in systolic heart failure is harmful. Little is known about the prevalence and the prognostic impact of dyssynchrony in HFPEF.

Methods:

We have designed a prospective, multicentre, international, observational study to characterize HFPEF and to determine whether electrical or mechanical dyssynchrony affects prognosis. Patients presenting with acute heart failure will be screened.

Inclusion criteria will be:

acute presentation with Framingham criteria for heart failure, left ventricular EF ≥45%, BNP >100 ng/L or NT-proBNP >300 ng/L. Patients will return in stable condition 4-8 weeks after the index presentation and undergo questionnaires, serology, ECG and Dopplerechocardiography. Thereafter, patients will be followed for mortality and heart failure hospitalization every 6 months for at least 18 months. Sub-studies will focus on echocardiographic changes from the acute presentation to the stable condition and on exercise echocardiography.

Conclusion:

KaRen aims to characterize electrical and mechanical dyssynchrony and to assess its prognostic impact in the HFPEF. The ancillary study of the exercise stress echocardiography sought to improve our understanding of HFPEF and generate answers to the question whether dyssynchrony could be a target for therapy in HFPEF.