The Morbidity & Mortality of Prevalent Heart Failure
The first study population included 292 unselected consecutive patients from the LLUMC heart failure clinic who were enrolled in the study from January to July 2006 and were followed up through the end of December 2010. The treatment policy at the clinic was to uptitrate dosages of beta-adrenergic blockade (β-blockers), angiotensin-converting-enzyme inhibitors (ACEi) and angiotensin II receptor blockers (ARB) to the most tolerable levels in order to reach target dosages, as recommended by the Heart Failure Society of America (HFSA). Patients were classified into systolic heart failure (ejection fraction (EF) < 40%) or diastolic heart failure (EF≥40%). All dosages of β-blockers, ACEi and ARB were extracted through chart reviews and were used as the main predictors of the patients' survival. Results from analyses showed that reaching target dosages of β-blockers and ACEi/ARB may increase survival when compared to not reaching target among the systolic HF population (HRβ_biockers= 0.64, 95% CI 0.26-1.56 and HRACEi/ARB=0.50, 95% Cl 0.22-1.14). Similarly, the HR of 0.48 (95% Cl 0.13-1.81) for β-blocker therapy and HR of 0.21 (95% Cl 0.04-1.07) for ACEi/ARB therapy suggests improvements in survival with these drug regiments among the diastolic HF population. Unfortunately, the study lacked power to make the observations statistically significant. A larger sample size is needed to adequately address the possible benefits of these drugs for heart failure patients. The second study is comprised of a random, representative sample of 200 cases of self-reported congestive health failure (CHF) and 260 non-cases from the Adventist Health Study-2 (AHS-2). A total of 67 cases and 147 non-cases were successfully contacted or contacted through proxy and their consents were obtained for medical record review. Consenting participants’ medical records were retrieved and examined for the validity of self-reported heart failure. The sensitivity of self-reported CHF was calculated as 97.4% and the specificity was 83.4%. The positive predictive value was 56.7% and the negative predictive value was 99.3 %. Total agreement (accuracy) between presence of self-reported heart failure and obtained physician-diagnosed heart failure from medical records was 86.0%. Further study with a larger sample is necessary to obtain reliable measures of validity of self-reported CHF in this population.
Biological Factors, Biostatistics, Cardiology, Cardiovascular Diseases, Clinical Epidemiology, Organic Chemicals, Public Health Education and Promotion, Vital and Health Statistics, Heart -- Diseases -- Mortality; Heart Diseases; Heart Failure -- diagnosis; Heart Failure, Systolic; Heart Failure, Diastolic; Heart Failure -- drug therapy; Heart Failure -- mortality; Prevalence; Retrospective Studies.
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