Impact of Diastolic Heart Failure on Health Care Utilization and Outcomes
Anita Deswal MD MPH MBBS
Houston VA Medical Center
Houston, TX
Funding Period: July 2003 - June 2005

BACKGROUND/RATIONALE:
Heart failure (HF) is a substantial public health problem in the US and within the VA. Nearly 5 million Americans have HF and 550,000 new cases are diagnosed each year. Heart failure may occur in the setting of either reduced ejection fraction (systolic heart failure or SHF) or preserved ejection fraction (diastolic heart failure or DHF). DHF may constitute 30-50% of the patients with HF. Although extensive data are available concerning the natural history, health care burden and treatment strategies for SHF, the estimated burden of DHF, especially in African American (AA) patients and in veterans with CHF, as well treatment strategies for DHF are still not well characterized. The proposed study will address these gaps in knowledge in VA beneficiaries with DHF.

OBJECTIVE(S):
The aims of this study are to: 1) To determine the prevalence, baseline characteristics and racial variation of DHF in veterans with HF.2) To determine the health care utilization in patients with DHF as compared to patients with SHF, and its variation according to race. 3) To determine the one and two-year mortality in patients with DHF as compared to patients with SHF, and its variation according to race.4) To determine if the use of two classes of medications (ACEI and b-blockers) is associated with a reduction in hospitalizations and mortality in patients with DHF, and whether this effect varies by race.

METHODS:
The study is a retrospective study of two VA national cohorts of patients with HF: 1) a cohort of pateints hospitalized with HF and 2) a cohort of ambulatory patients with HF treated at VA facilities between 10/99 and 09/02. Patients were identified in the national External Peer Review Program (EPRP) database that utilizes chart abstraction data and is maintained by the VHA Office of Quality Performance (OQP). Patients were classified as DHF and SHF based on the left ventricular ejection fraction performed within 1 year of the index date in the cohort. The study cohort were linked to other VA databases including the patient treatment file (PTF), outpatient clinic (OPC) files, Decision Support System (DSS) laboratory files and VA death files (BIRLS). Risk-adjusted measures of mortality, health care utilization and effect of medications (angiotensin converting enzyme inhibitors or ACE inhibitors and b-blockers) on mortality and hospitalizations are to be compared between patients with DHF vs. SHF, and by race within patients with DHF, using cox-proportional hazards modeling.

FINDINGS/RESULTS:
We have acquired the required data sets and linked the data for the study cohorts. Data validation of a subset of patients in the EPRP database from Houston has been performed. The cohort has been linked to the OPC, BIRLS and PTF files for evaluation of comorbidities, utilization and outcomes. The outpatient HF cohort consists of 17,456 patients, of which 9,500 had an assessment of their left ventricular ejection fraction (LVEF) within 1 year of the index date. Of these, 30% had a normal LVEF, i.e. were classified as DHF and 70% as SHF. There were 19,967 patients who were discharged with a primary diagnosis of HF and formed the inpatient cohort. Of these 17,000 had an LVEF assessed within 1 year of discharge; 27% were classified as DHF and 73% as SHF. Preliminary analyses of the SHF and DHF cohorts with baseline demographics and medication use have been conducted and the risk adjusted modeling for mortality and health-care utilization is now being performed.

IMPACT:
In the short-term this study will help to clarify the burden of DHF in veterans as well as in the VA health care system. It will help policy makers and researchers in deciding on the allocation of research resources to study the management and best practices for this condition and in the planning of multicenter studies of drug therapies for DHF within the VA. The proposed study is part of an incremental research agenda that aims to increase the awareness of the entity of DHF and to improve the process of care and outcomes for all patients with DHF, with a special emphasis on African American patients.

PUBLICATIONS:

Journal Articles

1. Deswal A, Bozkurt B. Comparison of morbidity in women versus men with heart failure and preserved ejection fraction. American Journal of Audiology. 2006; 97(8): 1228-31.
2. Deswal A, Mann DL. Can valsartan reduce the occurrence of atrial fibrillation in heart failure patients? National Clinical Practice of Cardiovascular Medicine. 2005; 2(10): 502-3.
3. Deswal A. Commentary: B-type natriuretic peptide consistently predicts death and cardiovascular events in heart failure. Evidence Based Medicine. BMJ (Clinical Research Ed.). 2005; 10: 150-150.
4. Deswal A. Diastolic dysfunction and diastolic heart failure: mechanisms and epidemiology. Current Cardiology Reports. 2005; 7(3): 178-83.
5. Soltero ER, Petersen NJ, Earle NR, Glaeser DH, Urbauer DL, Deswal A. Long-term results of coronary artery bypass grafting in patients with ischemic cardiomyopathy: the impact of renal insufficiency and noncardiac vascular disease. Journal of Cardiac Failure. 2005; 11(3): 206-12.
6. Singh H, Gordon HS, Deswal A. Variation by race in factors contributing to heart failure hospitalizations. Journal of Cardiac Failure. 2005; 11(1): 23-9.
7. Agoston I, Cameron CS, Yao D, Dela Rosa A, Mann DL, Deswal A. Comparison of outcomes of white versus black patients hospitalized with heart failure and preserved ejection fraction. American Journal of Audiology. 2004; 94(8): 1003-7.
8. Deswal A, Petersen NJ, Souchek J, Ashton CM, Wray NP. Impact of race on health care utilization and outcomes in veterans with congestive heart failure. Journal of The American College of Cardiology. 2004; 43(5): 778-84.

DRA: Chronic Diseases, Special (Underserved, High Risk) Populations
DRE: Epidemiology, Diagnosis and Prognosis, Resource Use and Cost
Keywords: Cardiovasc’r disease, Chronic heart failure, Utilization patterns
MeSH Terms: none