WeighT LOSS Surgery and Comprehensive Cardiometabolic Responses to to EXercise

The goal of this study is to define how treatment of obesity impacts cardiometabolic performance during exercise in patients with established HFpEF or at risk for HFpEF. Multi-dimensional physical activity, including 6 minute walk distance, resting metabolic rate, the metabolic cost of initiating exercise, and low-level, intermediate, peak exercise, and recovery oxygen utilization patterns will be examined in relation to weight loss in people having bariatric surgery. The investigators also aim to learn more about the relationship between obesity, exercise intolerance, and heart failure with preserved ejection fraction (HFpEF). The investigators are interested in the extent to which HFpEF\&#39;s manifestations are preventable or reversible with weight-loss interventions. The main questions it aims to answer are:

1. How does weight loss surgery affect comprehensive measures of physical activity?
2. What are the biochemical signatures of obesity and their reversibility in patients with HFpEF and obesity?

A prospective evaluation of subjects with HFpEF or at risk for HFpEF undergoing laparoscopic sleeve gastrectomy surgery to determine cardiometabolic responses to exercise.

The investigators will prospectively evaluate twenty-one patients to determine cardiometabolic responses to exercise before and 12-months after bariatric surgery. The investigators will map pulmonary/pulmonary vascular function, ventilatory efficiency (VE/VCO2 slope); left ventricular-systemic vascular function (based on echo measures) as well as exercise blood pressure responses (SBP at 30 Watts); sympathetic nervous system function during exercise will be assessed by heart rate-O2 pulse relationships; peripheral abnormalities characteristic of HFpEF will be measured by assessment of O2 kinetics during exercise onset and recovery. Additionally, global metabolic reserve will be captured by assessment of peak VO2. The comprehensive evaluation of these patients pre- and post-weight loss will further elucidate relationships between HFpEF and obesity, and their plasticity in response to weight loss, while also setting the stage to evaluate clinical trial endpoints that influence how patients function and feel (e.g. CPET-derived exercise capacity). The investigators will also assess exercise capacity and additional markers of metabolic health.

Eligibility Criteria:
Inclusion Criteria:

* Patients scheduled for weight loss surgery (gastric sleeve procedure)
* 40 years or older
* PMH one or more of the following:

  1. Diabetes Mellitus
  2. Hypertension requiring medical treatment
  3. Age \>65 years
  4. History of HFpEF
  5. Echocardiographic findings: left atrial enlargement (LAE), left ventricular hypertrophy (LVH), or right ventricular systolic pressure \>40 mmHg (RVSP)

Exclusion Criteria:

* Previous Bariatric surgery
* Pregnancy
* History of systolic heart failure, past or present LVEF of \<40%
* Inability to perform exercise testing on a cycle ergometer (i.e. orthopedic conditions that preclude cycling or walking, recent systemic illness that compromises exercise capacity).
* Any contraindication to performing exercise testing or any history of ventricular arrhythmia, any recent (within the last 3 months) or untreated supraventricular arrhythmia, elevated blood pressure at the time of presentation for exercise testing (\>155 mmHg systolic, or \>95 mmHg diastolic blood pressure), active or recent exacerbation of congestive heart failure, or history of reactive airways disease that is induced by exercise).

  * Acute myocardial infarction (3-5 days) or unstable angina
  * Uncontrolled symptomatic arrhythmias
  * Active endocarditis
  * Acute myocarditis or pericarditis
  * Symptomatic severe aortic stenosis
  * Acute pulmonary embolism or DVT
  * Suspected dissecting aneurysm
  * Uncontrolled asthma
  * Room air desaturation to \<85%
  * Acute non-cardiopulmonary disorder that may affect exercise performance (infection, orthopedic problem)