Clinical exacerbations as a surrogate end point in heart failure research
Background
We examined the utility of an index of clinical exacerbations of heart failure (HF) as a surrogate measure of outcome for use in modestly sized clinical trials and observational studies.
Methods
Electronic records of 189 outpatients with HF in a US Veterans Affairs Medical Center were examined over a 2- to 3-year period. Data collected included patient characteristics, clinical exacerbations of HF, hospitalizations, and deaths. Subsets of patient were also assessed for HF-related level of functioning.
Results
Episodes of clinical exacerbation could be detected reliably (kappa = .83). An index of episodes (number of episodes divided by the time in years) was associated with lower quality of life, higher functional class, increased rate of HF hospitalization, poorer exercise tolerance, and up to 30% increased risk of mortality across 2 years.
Conclusions
The index of HF exacerbations is potentially a useful surrogate end point for use in clinical HF research.
aPhiladelphia Veterans Affairs Medical Center, Philadelphia, Pennsylvania
bDepartment of Psychiatry of the University of Pennsylvania, Philadelphia, Pennsylvania
cSchool of Nursing of the University of Pennsylvania, Philadelphia, Pennsylvania
dDivision of Cardiology, Department of Internal Medicine of the University of Pennsylvania, Philadelphia, Pennsylvania.
Reprint requests: Steven L. Sayers, PhD, Philadelphia Veterans Affairs Medical Center, University and Woodland Avenues, Philadelphia, PA, 19104.
This work was supported by grant 0265447U from the American Heart Association, a VISN 4 Competitive Pilot Project Fund grant from the Department of Veterans Affairs, and the Mental Illness Research, Education, and Clinical Center of VISN 4. The project was performed at the Philadelphia VA Medical Center and the University of Pennsylvania Health System.
ABSTRACT