Cardiac Resynchronization and Iodine Meta-Iodobenzylguanidine (MIBG) Imaging
|Congestive Heart Failure||Drug: 123 iodine metaiodobenzylguanidine||Phase 1|
|Study Design:||Intervention Model: Single Group Assignment
Masking: No masking
Primary Purpose: Treatment
|Official Title:||Cardiac Resynchronization and MIBG Imaging|
- Change in 123I-MIBG parameters [ Time Frame: baseline, 6 months ]changes in 123I-MIBG parameters with cardiac performance including LVEF, stroke volume (SV), left ventricle (LV) and left atrium (LA) dimension, distance of 6-minute walk, NYHA class, and ventricular arrhythmic burden
- Change in submaximal exercise gas exchange [ Time Frame: baseline, 6 months ]Subjects will perform simplified low intensity cardiopulmonary exercise testing in our laboratory where they breathe for 1 min at rest, perform graded step exercise, increasing from 60, 90, 120 steps per minute until achieving a perceived exertion of 12-14 on the 6-20 Borg scale. This will be followed by a 1 min recovery. Subjects will be instrumented with ECG, pulse oximeter and breathe on a mouthpiece where ventilation, oxygen and carbon dioxide are measured continuously to calculate the desired parameters of ventilatory efficiency (VE/VCO2), PetCO2 and oxygen pulse (O2Pulse) on a breath by breath basis.
- Change in Autonomic function [ Time Frame: baseline, 6 months ]In addition to the simplified submaximal step test, subjects will also perform a simplified battery of tests for autonomic function. This will include supine to upright measures of heart rate and heart rate variability (HRV), paced breathing (slow to faster frequencies) as well as tracking HRV and responses to the increased metabolic demands of exercise and into recovery.
|Study Start Date:||February 2012|
|Study Completion Date:||February 2016|
|Primary Completion Date:||February 2016 (Final data collection date for primary outcome measure)|
Subjects will be imaged with 123 iodine metaiodobenzylguanidine.
Drug: 123 iodine metaiodobenzylguanidine
10 millicurie (mCi) (370 MBq)
Other Name: AdreView
The Specific Aim #1 of this study is to assess, with 123iodine metaiodobenzylguanidine (123I-MIBG imaging), whether cardiac resynchronization therapy (CRT) rebalances and improves the integrity and function of sympathetic nerve terminals in the failing myocardium. The study will test the hypothesis that resynchronization of biventricular contractility attenuates excessive sympathetic drive, and improves autonomic function and cardiac performance.
The Specific Aim #2 of this study is to determine the relationship between 123I-MIBG labeling of sympathetic activity and physiological measures of cardiopulmonary and autonomic function. This aim is to test the hypothesis that impaired cardiac sympathetic activity, determined by 123I-MIBG imaging will be associated with poorer submaximal exercise gas exchange (higher ventilation - carbon dioxide (CO2) slopes, low end tidal CO2, reduced oxygen pulse and a more rapid frequency response) as well as reduced heart rate power spectral frequencies, a blunted response to positional changes and a delayed heart rate recovery.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01522378
|United States, Minnesota|
|Mayo Clinic in Rochester|
|Rochester, Minnesota, United States, 55905|
|Principal Investigator:||Yongmei Cha, MD||Mayo Clinic|