Weight Loss as Therapy for Heart Failure With Preserved Ejection Fraction

Inclusion Criteria: * BMI \> 30 * Able to perform 6 minute hall walk test * Left Ventricular ejection fraction \>45% * Diagnosis of heart failure with preserved ejection fraction (HFpEF) ; confirmation of HFpEF based on 1 major or 3 minor criteria listed below. Major: 1. Elevated BNP \>200 2. cardiogenic pulmonary edema 3. Pulmonary capillary wedge pressure at rest \>15 mmhg or with exercise \>25 mmhg using invasive right heart pressure measurement Minor: 1. Left atrial enlargement (volume \>68 ml) 2. increased left ventricular wall thickness (\>1.1cm) by echocardiography 3. E/e' \>15 4. intermediate level of BNP, 60-199 Exclusion Criteria: * uncontrolled blood pressure * severe chronic obstructive pulmonary disease (oxygen or steroid dependent) * recurrent major depression. presence or history of suicide behavior, and current substantial depressive symptoms. Antidepressant drugs are allowed if the dose has been stable for 3 months * other major psychiatric illness (schizophrenia, bipolar, dementia) * significant hepatic dysfunction * untreated hypothyroidism or hyperthyroidism * history of drug or alcohol abuse or dependency within the past 12 months * acute coronary syndrome without revascularization in the past 12 months * acute coronary syndrome with revascularization in the past 6 months * Cerebrovascular accident or transient ischemic attack in the past 6 months * cancer or terminal illness with life expectancy \< 3 years * history of medical noncompliance * significant anemia (hgb \<9) * life threatening or uncontrolled arrhythmia * hemodynamically relevant valvular heart disease * infiltrative heart disease including cardiac amyloidosis, sarcoidosis, Fabry's disease * genetic hypertrophic cardiomyopathy * significant pericardial disease * clinically relevant neuromuscular disease * pregnant or may become pregnant in the next 6 months * prior major organ transplant or intent to transplant ( on the transplant list) * pacemaker dependant * clinically significant congenital heart disease that may be cause of symptoms