Lung Impedance Monitoring In Treatment of Chronic Heart Failure (LIMIT-CHF)
Heart failure is a major clinical problem that is increasing in magnitude and the cost of management of heart failure is escalating. A significant part of this cost is related to unplanned acute presentation to emergency departments and hospitalisation with worsening shortness of breath due to increased fluid content in the lungs.
Many heart failure patients are already fitted with defibrillators to protect them from the risk of fast heart rhythms and sudden death and are followed up in both the heart failure clinics and defibrillator clinics. Recently some of the defibrillators fitted have been equipped with an extra function that can detect and warn of changes in the fluid content of the lungs very early even before the patient starts to complain of any shortness of breath and before any signs of fluid overload are seen clinically. However, it is not known how to deal with these warnings if they occur very early and it is not known whether a medical intervention at his stage is beneficial to prevent progression and eventual hospital admission. In the majority of cases, early warnings of this kind are ignored or this function is disabled at implantation of the device.
The current study will involve patients who have already been fitted with a device with the above capability. The investigators will use the new function to guide management of these patients and compare their outcome with similar patients who are fitted with devices without it. The investigators will attempt to manage early warnings by a predetermined increase in medications in a group of patients and compare their clinical course to a similar group in whom no action is taken.
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||Lung Impedance Monitoring In Treatment of Chronic Heart Failure|
- The number of unplanned hospitalisations or acute unscheduled care in the emergency department or heart failure clinic [ Time Frame: 1 year ]The primary study end-point will be a comparison between groups 1 and 2 regarding the ratio of the number of readmissions for heart failure to the total number of patients in each group of the two main groups over the course of the study (i.e. number of readmissions per patient)
- NYHA functional Class improvement of at least 1 grade [ Time Frame: 1 year ]The proportion of patients achieving at least 1 grade improvement in New York Heart Association functional class in each group
- Minnesota Quality of Life Score improvement in each group [ Time Frame: 1 Year ]A comparison between the 2 study groups regarding the magnitude of improvement in the Minnesota Living with Heart Failure (questionnaire) score at 1 year compared to baseline
- Change in the 6 minute walk test(6MWT)distance in metres [ Time Frame: 1 year ]A comparison between the change in the 6MWT distance covered (at 1 year compared to baseline) in each of the 2 study groups
- Change in the level of BNP in serum (pg/ml) [ Time Frame: 1 year ]A comparison between between the 2 study groups regarding the change in level of BNP at 1 year compared to baseline
|Study Start Date:||September 2010|
|Study Completion Date:||December 2014|
|Primary Completion Date:||October 2014 (Final data collection date for primary outcome measure)|
|Experimental: Group 1: Optivol Group||
Drug: Preset increase in frusemide dose
All patients in Group 1 will have the Optivol function and alerts switched on. Optivol levels will be downloaded monthly via the Medtronic Carelink Network (for those patients who have it) or during pacemaker follow up appointments.
If the Optivol alarm goes off, all patients will be requested to contact a member of the research team by phone and those with rising Optivol (irrespective of the presence or absence of heart failure symptoms) will be requested to increase the dose of diuretic that they are on by 50% for 1 week then revert to their usual dose after 7 days. A routine renal function check will be performed at the end of the week.
|Active Comparator: Group 2: Optivol alarm muted||
Other: No intervention
The Optivol data for these patients will be downloaded periodically (at each scheduled device check) and recorded but will not be available at follow up in the heart failure clinic.. These patients will act as controls for group 1 patients. They will undergo baseline investigations and then will undergo routine heart failure treatment and follow-up in the heart failure clinic. These will include a routine clinical evaluation, body weight and blood analysis as per the heart failure clinic protocol. Medications will be reviewed and changed according to clinical needs.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01320007
|St Bartholomew's Hospital|
|London, United Kingdom, EC1A 7BE|
|Principal Investigator:||Richard J Schilling, Md FRCP||Barts and the London NHS Trust, Queen Mary University of London|