30 patients suffering from Heart Failure with Ejection Fraction less than 40% start Cardiac Rehabilitation Programme, serum KLOTHO Hormone level and other labs and Echo measurements will be taken on the first visit.

After completion of 3-month Rehabilitation Programme the second set of labs and Echo measurements will be taken.

Than participants will be divided for 2 groups: the patients who wish to continue Rehabilitation programme for additional 3-month period and the second group that prefer to stop Rehabilitation programme after completion of the first 3 month period.

For both groups additional set of labs will be taken this time and at the end of the study.

The Aim of the study: to investigate association between serum KLOTHO level, physical activity and possible correlation with laboratory and echocardiographic parameters in cohort of Heart Failure patients.

30 patients, age range older than 18 years old suffering from Heart Failure, Functional capacity II-III and echocardiographic evidence of Left Ventricular Ejection Fraction less than 40% beginning Cardiac Rehabilitation Programme. Following recruitment of patients to the study each one will undergo serum KLOTHO Hormone level assessment along with kidney functions, N terminal -Pro B-Type Natriuretic Peptide hormone activity and Echo measurements .

After completion of 3-months Exercise based Rehabilitation Programme set at 70-80% of maximal individual exercise capacity,a second identical set of lab tests and Echo measurements will be performed.

After than participants will be divided into 2 groups: Group I will comprise patients who wish to continue Rehabilitation programme for additional 3-months period and the Group II those who will stop Exercise Rehabilitation programme following completion of the first 3 months.

Both groups will undergo additional set of lab tests at this six-months-point. Except for the primary and secondary end-points all possible correlations between serum KLOTHO level and age, sex, Ejection Fraction, functional capacity, N terminal -Pro B-Type Natriuretic Peptide hormone activity hormone level and kidney function indices will be evaluated.

Inclusion Criteria:

1. Both genders
2. Patients ≥ than 18 years
3. Ejection Fraction ≤ than 40 %

Exclusion Criteria:

1. Myocardial Infarction ≤ than 1.5 month before inclusion
2. Renal failure with Creatinine ≥ 1.5 mg/dl
3. Known Inflammatory condition.
4. Patient taking Calcium Supplement,Vitamin D or pyrophosphate.

30 patients suffering from Heart Failure and beginning Rehabilitation Programme