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.

Inclusion Criteria:

1. Acute presentation to the hospital with clinical signs and symptoms of HF, according to the Framingham criteria [19].
2. LVEF ≥ 45% by echocardiography within the first 72 hours. The measurement will be carried out according to guidelines
3. BNP >100 ng/L or NT-proBNP >300 ng/L.

Exclusion Criteria:

1. Evidence of primary hypertrophic or restrictive cardiomyopathy or systemic illness known to be associated with infiltrative heart disease
2. Known cause of right heart failure not related to left ventricular dysfunction
3. Pericardial constriction
4. Clinically significant pulmonary disease, as evidenced by requirement of current home oxygen
5. End-stage renal disease currently requiring dialysis
6. Bi-ventricular pacemaker (CRT). (Patients who have a conventional pacemaker may be included)
7. Anticipated or indication for cardiac surgery. (Patients who have indication for surgery but may not undergo surgery because of some contraindication, for example age, may NOT be included).
8. Anticipated percutaneous intervention on aortic stenosis. (Patients who undergo other percutaneous intervention, for example PCI, may be included).

Patients presenting acutely of congestive heart failure and diagnosed according to current ESC guidelines to have an heart failure with preserved ejection fraction (LV EF > or = 45%)