Browsing by Author "Chitnis, Abhishek"
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Item Angiotensin-Converting Enzyme Inhibitors/Angiotensin Receptor Blockers, Statins and Dementia in Patients with Heart Failure(2012-12) Chitnis, Abhishek; Johnson, Michael L.; Aparasu, Rajender R.; Chen, Hua; Kunik, Mark E.; Schulz, Paul E.Heart failure (HF) and dementia are common medical conditions in older adults.(1) More than 5.5 million adults have HF in the United States (US) and the incidence approaches 10 per 1000 population after 65 years of age. HF Heart failure (HF) is associated with increased risk of dementia and dementia that is a major growing public health problem in the United States and worldwide. One in six individuals older than 70 have dementia with prevalence increasing exponentially with advanced age. As a result, it is estimated that the number of dementia cases in 2050 will increase threefold compared with 2000. Dementia is an independent predictor of increased mortality in HF patients. There is increasing evidence that hypertension and dyslipidemia are associated with an increase in the risk of dementia, but it remains unclear whether anti-hypertensive and lipid-lowering agents alter the risk of dementia. The goal of this study is to test whether angiotensin-converting enzyme inhibitors /angiotensin receptor blockers (ACEIs/ARBs) and statins alter the risk of dementia in patients with heart failure. Specific Aim 1 is to determine factors that predict treatment with ACEIs/ARBs and statins and to calculate propensity scores that will be used in Aim 3. Specific Aim 2 is to test the association of ACEIs/ARBs and statins and time to dementia diagnosis in patients with heart failure using Cox hazards model. Specific Aim 3 is to extend the analysis to marginal structural models and compare results from Aim 2 to estimates obtained from marginal structural models. We determined variation in incidence rates of dementia associated with socio-demographic factors (age, sex) and clinical factors (comorbid disease conditions and co-medications). We obtained propensity scores of treatments (ACEIs/ARBs and statins).To determine the unique effects of ACEIs/ARBs and statins after controlling for potential confounding factors, we adjusted for socio-demographic factors, comorbidities and co-medications in Cox hazards model of time to first diagnosis of dementia. Marginal structural models using inverse probability of treatment weighting were used to test treatment effects, and results were compared to results obtained from Cox hazards regression. We conducted this study in a cohort of elderly with HF enrolled in a local Medicare Advantage Prescription Drug plan from 2008 to 2011. The study adds to the only outcomes, mortality and hospitalization considered in management of HF thus improving the quality of care. The findings from this observational study will help to address determinants of variation in treatment and our long range goal is to identify strategies to reduce the risk of dementia in this frail HF population.Item Risk of Hospitalization among Elderly Heart Failure Patients initiating Beta-Blockers or ACE-Inhibitors(2014-08) Gupta, Parul; Johnson, Michael L.; Aparasu, Rajender R.; Chen, Hua; Sherer, Jeffrey T.; Chitnis, AbhishekObjective: For elderly(age≥65 years) Heart Failure(HF) patients an early initiation of Beta-Blockers(BBs) vs. Angiotensin-Converting Enzyme Inhibitor(ACEIs) could have an impact on the risk of HF hospitalization. Thus the aim of this study is to estimate the determinants of initiating a therapy and their risk of first HF hospitalization, of recurrent HF hospitalization and composite outcome of HF hospitalization with death as the terminal event. Methods: Using 2008-2011 Medicare Advantage Prescription Drug Plan, elderly HF patients initiating ACEI or BBs, defined as category 1(BBc1 e.g. Metoprolol, Bisoprolol etc.) and category 3(BBc3 e.g. Carvedilol and Labetalol), were identified. The baseline determinants of initiating either of these drugs were identified by Multinomial logistic regression analysis. The survival probabilities of first HF hospitalization, recurrent HF hospitalization and of composite outcome were obtained by inverse probability weighted count process model, by stratified total time and gap model and by the marginal model respectively for a follow-up of a year using SAS 9.3 at the p-value of 0.05. Results: Of all 6430 eligible patients, there were 248(3.86%) events of first HF hospitalization with 55(0.86%) events of ≥2 recurrent hospitalization. Of these, ACEI, BBc1, BBc3 and a combination of ACEI with BBc1(ABC1) and with BBc3(ABC3) were initiated by 1194(18.57%), 1519(23.62%), 490(7.62%), 257(4.00%) and by 126(1.96%) patients respectively. This likelihood for initiating BBc1 compared to ACEI increased statistically significantly by atrial fibrillation/flutter(OR:1.348,95%CI:1.09-1.667), Age(OR:1.017,95%CI:1.005-1.028), with vasodilators(OR:1.373,95%CI:1.051-1.795) and with a missing BNP value(OR:1.97,95%CI:1.085-3.578). For initiating BBc3 compared to ACEI the likelihood increased statistically significantly for males(OR:1.294,95%CI:1.039-1.612), for patients with chronic atherosclerosis(OR:1.502,95%CI:1.12-2.015), for those taking vasodilators(OR:1.600,1.144-2.238) or Diuretics (OR:1.306,95%CI:1.05-1.625) or having an elevated BNP value(OR:2.465,95%CI:1.008-6.029). It decreased statistically significantly for patients taking Calcium Channel Blockers(OR:0.718,95%CI:0.547-0.942) in the washout period. The hazard ratio for 3 respective outcomes were 0.562(95%CI:0.28- 1.13), 0.969(95%CI: 0.47- 1.996) and 1.32(95%CI: 0.702- 2.483) for BBc1 as the initiation therapy. For BBc3, these were 1.242(95%CI:0.64- 2.43), 0.871(95%CI: 0.51- 1.48) and 1.41(95%CI: 0.84- 2.36) respectively. Conclusions: There is a statistically non-significant difference in the effect of an early initiated BB in comparison to ACEI for the risk of HF hospitalization.