Congestive heart failure incidence and prognosis: case identification using central adjudication versus hospital discharge diagnoses.

PURPOSE: We compared hospitalized congestive heart failure (CHF) incidence and prognosis estimates using hospital discharge diagnoses or central adjudication. METHODS: We used the Cardiovascular Health Study (CHS), a population-based cohort study of 5888 elderly adults. A physician committee adjudicated potential CHF events, confirmed by signs, symptoms, clinical tests, and/or medical therapy. A CHF discharge diagnosis included any of these ICD-9 codes in any position: 428, 425, 398.91, 402.01, 402.11, 402.91, and 997.1. We constructed an inception cohort of 1209 hospitalized, nonfatal, incident CHF cases, identified by discharge diagnosis, adjudication, or both. RESULTS: Incidence rates for hospitalized CHF were 24.6 per 1000 person-years using discharge diagnoses and 17.1 per 1000 person-years using central adjudication. Compared to the group identified as having CHF by both methods, the group with only a discharge diagnosis (hazard ratio=0.77, 95% confidence interval=0.65-0.91) and the group with central adjudication only (hazard ratio=0.72, 95% confidence interval=0.55-0.94) had lower mortality rates. CONCLUSIONS: In the elderly, studies using only discharge diagnoses, as compared to central adjudication, may estimate higher rates of incident hospitalized CHF. Mortality following CHF onset may be similar for these methods and higher if both methods are used together.

Weight loss, muscle strength, and angiotensin-converting enzyme inhibitors in older adults with congestive heart failure or hypertension.

OBJECTIVES: To determine whether angiotensin-converting enzyme (ACE) inhibitor use may be associated with weight maintenance and sustained muscle strength (measured by grip strength) in older adults. DESIGN: Data from the Cardiovascular Health Study (CHS), a community-based prospective cohort study of 5,888 older adults, were used. SETTING: Subjects were recruited from four U.S. sites beginning in 1989; this analysis included data through 2001. PARTICIPANTS: CHS participants with congestive heart failure (CHF) or treated hypertension. MEASUREMENTS: The exposure, current ACE inhibitor use, was ascertained by medication inventory at annual clinic visits; the outcomes were weight change and grip-strength change during the following year. Multivariate linear regression was used, accounting for correlations between observations on the same participant over time. RESULTS: The average annual weight change was -0.38 kg in 2,834 participants (14,443 person-years) with treated hypertension and -0.62 kg in 342 participants (980 person-years) with CHF. ACE inhibitor use was associated with less annual weight loss after adjustment for potential confounders: a difference of 0.17 kg (95% confidence interval (CI)=0.05-0.29) in those with treated hypertension and 0.29 kg (95% CI=-0.25-0.83) in those with CHF. There was no evidence of association between ACE inhibitor use and grip-strength change. CONCLUSION: ACE inhibitor use may be associated with weight maintenance, but not maintenance of muscle strength, in older adults with treated hypertension.

Socioeconomic status and survival from out-of-hospital cardiac arrest.

BACKGROUND: Socioeconomic status (SES) has been linked to heart disease, but its influence on outcome from out-of-hospital cardiac arrest (OHCA) is not well understood. OBJECTIVES: The authors hypothesized that higher levels of SES would be associated with better survival, potentially through demographic, circumstance, or care factors. METHODS: A cohort investigation of OHCA due to heart disease treated by emergency medical services between January 1, 1999, and December 31, 2003, was conducted in the study county. Socioeconomic status was assessed using two different measures: an individual-level measure, tax-assessed property value per unit, and a geography-based measure, median household income from the 2000 Census. The authors used logistic regression to evaluate the association between survival to hospital discharge and quartile of SES. Models systematically adjusted for demographic, circumstance, and care factors that could potentially confound the association. RESULTS: Socioeconomic status as measured by value per unit was associated with survival in unadjusted models (odds ratio [OR] = 1.21; 95% confidence interval [95% CI] = 1.05 to 1.36, for each successive increase in value-per-unit quartile). Adjustment for demographic, circumstance, and care factors altered the association only slightly (fully adjusted OR = 1.23; 95% CI = 1.08 to 1.39). In contrast, SES as measured by median household income was not associated with survival. The study could not investigate all potentially explanatory factors. The findings may not be generalizable to persons or communities that differ from the current investigation. CONCLUSIONS: An individual-level, but not an area-level, measure of SES predicted survival following OHCA independent of demographic, circumstance, or care factors. Future research should continue to investigate mechanisms through which SES is associated with OHCA survival.

Weight change and the risk of gestational diabetes in obese women.

BACKGROUND: Obesity is an established risk factor for gestational diabetes. It is not known whether this risk might be reduced through weight loss between pregnancies. We sought to determine whether weight loss between pregnancies reduced the risk of gestational diabetes among obese women. METHODS: We conducted a population-based cohort study of 4102 women with 2 or more singleton live births in Washington State between 1992 and 1998. All subjects were nondiabetic and obese (at least 200 lbs) at their first birth during these years. Weight change was calculated as the difference between prepregnancy weight for the 2 pregnancies. We estimated relative risks of gestational diabetes at the subsequent delivery through stratified analyses and Mantel-Haenszel estimates. RESULTS: Thirty-two percent of women lost weight between pregnancies, with a mean weight loss of 23 lbs. Women who lost at least 10 lbs between pregnancies had a decreased risk of gestational diabetes relative to women whose weight changed by less than 10 lbs (relative risk = 0.63; 95% confidence interval = 0.38-1.02, adjusted for age and weight gain during each pregnancy). Of the 61% of women who gained weight between pregnancies, the mean weight gain was 22 lbs. Women who gained at least 10 lbs had an increased risk of gestational diabetes (1.47; 1.05-2.04). CONCLUSIONS: Even moderate changes in prepregnancy weight can apparently affect the risk of gestational diabetes among obese women. This may offer further motivation for interventions aimed at reducing obesity among women of reproductive age.

Survival associated with two sets of diagnostic criteria for congestive heart failure.

Congestive heart failure (CHF) definitions vary across epidemiologic studies. The Framingham Heart Study criteria include CHF signs and symptoms assessed by a physician panel. In the Cardiovascular Health Study, a committee of physicians adjudicated CHF diagnoses, confirmed by signs, symptoms, clinical tests, and/or medical therapy. The authors used data from the Cardiovascular Health Study, a population-based cohort study of 5,888 elderly US adults, to compare CHF incidence and survival patterns following onset of CHF as defined by Framingham and/or Cardiovascular Health Study criteria. They constructed an inception cohort of nonfatal, hospitalized CHF patients. Of 875 participants who had qualifying CHF hospitalizations between 1989 and 2000, 54% experienced a first CHF event that fulfilled both sets of diagnostic criteria (concordant), 31% fulfilled only the Framingham criteria (Framingham only), and 15% fulfilled only the Cardiovascular Health Study criteria (Cardiovascular Health Study only). No significant survival difference was found between the Framingham-only group (hazard ratio = 0.87, 95% confidence interval: 0.71, 1.07) or the Cardiovascular Health Study-only group (hazard ratio = 0.89, 95% confidence interval: 0.68, 1.15) and the concordant group (referent). Compared with Cardiovascular Health Study central adjudication, Framingham criteria for CHF identified a larger group of participants with incident CHF, but all-cause mortality rates were similar across these diagnostic classifications.

Genetic variants of coagulation factor XIII, postmenopausal estrogen therapy, and risk of nonfatal myocardial infarction.

We hypothesized that possession of either of 2 functional coagulation factor XIII polymorphisms, one within subunit A (Val34Leu) and one within subunit B (His95Arg), might modulate the prothrombotic effects of estrogen and help to explain the variation in incidence of arterial thrombotic events among postmenopausal women using hormone replacement therapy. In a population-based case-control study of 955 postmenopausal women, we assessed the associations of factor XIII genotypes and their interactions with estrogen therapy on risk of nonfatal myocardial infarction (MI). The presence of the factor XIIIA Leu34 allele was associated with a reduced risk of MI (odds ratio [OR] = 0.70, 95% confidence interval [95% CI] = 0.51-0.95). The presence of the factor XIIIB Arg95 allele had little association with MI risk. Neither factor XIII polymorphism alone significantly modified the association between the risk of MI and current estrogen use. In exploratory analyses, however, there was a significant factor XIII subunit gene-gene interaction. Compared to women homozygous for both common factor XIII alleles, the Arg95 variant was associated with a reduced risk of MI in the presence of the Leu34 variant (OR = 0.36, 95% CI = 0.17-0.75) but not in the absence of the Leu34 variant (OR = 1.11, 95% CI = 0.69-1.79). Moreover, among women who had at least 2 copies of the variant factor XIII alleles and were current estrogen users, the risk of MI was reduced by 70% relative to estrogen nonusers with fewer than 2 factor XIII variant alleles (P value for interaction =.03). If confirmed, these findings may permit a better assessment of the cardiovascular risks and benefits associated with postmenopausal estrogen therapy.