Cardiac Metabolic Remodeling After Pulmonary Vasodilator Therapy in Pulmonary Arterial Hypertension: A Pilot Study

University of Wisconsin, Madison2 enrolled

Overview

Pulmonary arterial hypertension(PAH) is associated with the development of right heart failure. In the setting of heart failure, the heart shifts to increasing dependence on glucose metabolism. In this study, the investigators will perform cardiac positron emission tomography/magnetic resonance imaging (PET/MRI) scans to measure glucose metabolism in the heart before and after initiation of pulmonary vasodilator therapy for pulmonary arterial hypertension.

Pulmonary arterial hypertension is associated with the development of right heart failure. In the setting of heart failure, the heart shifts to increasing dependence on glucose metabolism. In this study, the investigators will perform cardiac positron emission tomography/magnetic resonance imaging (PET/MRI) scans to measure glucose metabolism in the heart before and after initiation of pulmonary vasodilator therapy for pulmonary arterial hypertension. By utilizing a rest-exercise protocol and continuous PET imaging acquisition, we can capture real-time changes in glucose uptake in the heart in response to acute exercise. By coupling these measures of dynamic glucose utilization with MRI-based cardiac function, we will determine cardiac metabolic efficiency.

Study Type

OBSERVATIONAL

Enrollment

Conditions

Pulmonary Arterial Hypertension Right-Sided Heart Failure

Interventions

Eligibility

Sex: ALLMin age: 18 YearsMax age: 75 Years

Medical Language ↔ Plain English

Inclusion Criteria: * World Health Organization(WHO) group PAH secondary into idiopathic pulmonary arterial hypertension(IPAH) or connective tissue disease associated pulmonary arterial hypertension (CTDPAH) * New York Heart Association (NYHA) classification I - III heart failure * Vasodilator therapy naive * Able to provide informed consent Exclusion Criteria: * Metabolic disorders such as uncontrolled diabetes (A1c \> 8%) that may interfere with FDG uptake * Baseline 6-minute walk distance (6MWD) \< 400 feet or NYHA class IV heart failure * Musculoskeletal abnormalities that would prevent exercise * Contraindications to MRI

Outcomes

Primary Outcomes

Ability to augment glucose uptake ("substrate flexibility"), defined as change in rate of glucose uptake from rest to exercise

Substrate flexibility is defined as the change in myocardial to blood pool glucose uptake rate from rest to exercise.

Time frame: 6 months

Secondary Outcomes

Change in substrate flexibility after initiation of pulmonary vasodilator therapy

Substrate flexibility is defined as the change in myocardial to blood pool glucose uptake rate from rest to exercise. Substrate flexibility before and after pulmonary vasodilator therapy will be compared.