Characterization of Changes in Ventricular Mechanics in Response to Lexiscan Stress Using Tagged Cine Cardiac Magnetic Resonance Imaging

Recruitment & Eligibility

Inclusion Criteria

Myocardial rest/regadenoson stress perfusion PET study within 60 days
Normal rest LVEF (greater than or equal to 50%)
No change in symptoms or treatment between the PET and the MRI study
Willing to consent to the study
Male or female who is either post-menopausal, surgically sterile, or if has a childbearing potential, a negative pregnancy test within 2 days prior to the MRI study.

Exclusion Criteria

Renal dysfunction (estimated glomerular filtration rate < 60 mL/min/1.73m2) within 6 months
Metallic implants, pacemaker, blood vessel clip (contra-indicated for MRI)
Patient size exceeds MRI bore/table limits: (Max body diameter > 60 cm, weight > 136 kg)
History of gadolinium contrast allergy or intolerance
Second or third degree AV block
Sinus node dysfunction
Acute myocardial infarction (past 3 months)
Actively wheezing or with acute asthma or bronchospastic attacks requiring changes in therapy within the past 30 days
Patients that have experienced a previous hypersensitivity reaction thought to be related to regadenoson

Study & Design

Arm && Interventions

Group	Intervention	Description
Regadenoson	Regadenoson	Regadenoson is a single-use, pre-filled syringe containing 0.4 mg/5 mL of regadenoson.

Primary Outcome Measures

Name	Time	Method
RADIAL STRAIN	Day 1	A measurement of the relative displacement between myocardial points between end-diastole and end-systole along a common ray extending from the center of the left ventricular (LV) cavity (analogous to myocardial thickening). A normal radial strain is indicated by a positive decimal value and can be understood as the percentage change in wall thickness of a myocardial segment. A POSITIVE change in radial strain indicates an increase in wall thickening. Because strain is a measurement in change in length (distance) divided by an original length (distance) it is considered unitless.
CIRCUMFERENTIAL STRAIN	Day 1	A measurement of the relative displacement of myocardial points directed along the circumference of the ventricular wall at a given radial distance from the left ventricular (LV) cavity center (e.g. midline). A normal circumferential strain is indicated by a negative decimal value and can be understood as the percentage shortening along the ventricular wall with a greater negative value indicating greater ventricular shortening along the circumference. A positive change in strain would therefore be interpreted as a decrease in circumferential shortening. Because strain is a measurement in change in length (distance) divided by an original length (distance) it is considered unitless.

Secondary Outcome Measures

Name	Time	Method
Late Gadolinium Enhancement (LGE) and RADIAL Myocardial Strain	Day 1	For each subject, the 16-segments were visually assessed along the short-axis plane for the presence of LGE. These images were collected post regadenoson stress recovery using an inversion-recovery prepared, fast gradient echo sequence and a delay of at least 8 minutes after administration of a single dose of gadobenate dimeglumine. The presence of LGE within a segment is a separate classification of segment type. The segment classifications in the other outcomes are determined from the prior positron-emission-tomography (PET) examination where the LGE determination is based solely on cardiac magnetic resonance (CMR) imaging collected data. The measurement was performed to determine if the presence of LGE within a particular segment affect the resulting strain?
Adverse Events	Day 1	Adverse events were monitored and recorded on a specific Adverse Event (AE) log.
Late Gadolinium Enhancement and CIRCUMFERENTIAL Myocardial Strain	Day 1	The Effects of the presence of LGE on CIRCUMFERENTIAL myocardial Strain

Recruitment & Eligibility