Margaret M. Redfield

Plasma brain natriuretic peptide concentration: impact of age and gender

OBJECTIVES We wished to examine the effects of age and gender on plasma brain natriuretic peptide (BNP) concentration in a population-based study. BACKGROUND Measurement of BNP concentration is approved for use in the diagnosis of heart failure and may aid in the detection of left ventricular dysfunction. Although BNP is approved for clinical use, there are few data regarding the range of BNP observed in persons without cardiovascular disease or cardiac dysfunction. These data are essential for the interpretation of BNP. METHODS In 2,042 randomly selected residents of Olmsted County, Minnesota, >44 years old, BNP (Shionogi and Biosite assays), Doppler echocardiography, and medical record review were performed. A normal subset of subjects (n = 767) in sinus rhythm without cardiovascular, renal, or pulmonary disease or diabetes; on no cardiovascular medications; and with normal systolic, diastolic, and valvular function was identified. RESULTS Within the normal subset, the distribution of BNP differed by age, gender, and assay system. With both assays, BNP increased significantly with age and was significantly higher in women than men, leading to age-, gender-, and assay-specific reference ranges. Receiver operating characteristic analysis for the ability of BNP to detect an ejection fraction < or = 40% was performed in each age/gender stratum in the entire cohort (n = 2,042) and confirmed that discriminatory values for BNP for detection of reduced ejection fraction were higher in women and older persons and were different between the two assays. CONCLUSIONS Interpretation of BNP should include consideration of age-, gender-, and assay-specific partition values.

Left Atrial Volume as an Index of Left Atrial Size: A Population-Based Study

OBJECTIVES We studied left atrial volume (LAV) as an index of atrial size. BACKGROUND Increased left atrial dimension (LAD) measured by M-mode echocardiography is a risk factor for atrial fibrillation, stroke, and death. METHODS A random sample of residents of Olmsted County, Minnesota, age > or =45 years (n = 2,042) underwent Doppler echocardiography with assessment of LAD and LAV. A subgroup of the population (n = 767) with no cardiovascular disease and normal systolic and diastolic function was used to develop reference ranges for LAD and LAV. In the total population, the prevalence of left atrial enlargement and the association between cardiovascular disease and left atrial size as determined by both indexes were assessed. RESULTS In the normal subgroup, both indexes were associated with gender and body size, thus models controlling for body size were used to determine gender-specific reference ranges for LAD and LAV. In the total population, left atrial enlargement was common, with a prevalence of 18% (men) and 12% (women) using LAD/body surface area (BSA) and of 16% (men and women) using LAV/BSA. The agreement between the indexes was only fair (kappa = 0.53). Adjusting for age and gender, LAV/BSA was more strongly associated with the presence of cardiovascular diseases than LAD/BSA. CONCLUSIONS We described a simple technique of measuring LAV, examined methods for indexing LAV, and described its normal range in a large, healthy reference cohort. Further, we find that in the community, left atrial enlargement is common and reflects the burden of cardiovascular disease.

Heart failure after myocardial infarction: clinical presentation and survival.

To characterize the presentation and outcome of patients with heart failure (HF) after myocardial infarction (MI) according to left ventricular ejection fraction (LVEF) and test the hypothesis that the outcome of HF did not change over time.

Use of ejection fraction tests and coronary angiography in patients with heart failure.

OBJECTIVE To examine the use of tests that measure ejection fraction (EF) and the use of coronary angiography among patients with an initial diagnosis of heart failure (HF). PATIENTS AND METHODS All potential cases of incident HF in Olmsted County, Minnesota, between 1979 and 1999 were identifled. In a random sample of cases validated with the Framingham criteria, we examined the frequency of tests that measure EF (echocardiography, radionuclide ventriculography, and left ventricular angiography) and coronary angiography within 90 days after diagnosis. RESULTS A total of 655 patients with incident HF were included in the analysis. The use of tests that measure EF and coronary angiography increased early in the study period but stabilized thereafter. In the most recent years (1995-1999), EF was measured in 65% of the patients and coronary angiography performed in 12%. After adjustment for year of diagnosis, body mass index, hypertension, diabetes mellitus, smoking, hyperlipidemia, comorbidity, prior myocardial infarction, and prior angina, men were more likely than women to have EF measured (odds ratio [OR], 1.47; 95% confidence interval [CI], 1.01-2.16) and coronary angiography (OR, 2.61; 95% CI, 1.43-4.76). Increasing age was associated with less use of tests (OR, 0.83; 95% CI, 0.76-0.91; for EF measurement; OR, 0.72; 95% CI, 0.63-0.82; for coronary angiography for every 5-year increase in age). CONCLUSION Among patients with HF, tests that measure EF are used substantially less than recommended, and coronary angiograms are used infrequently. Use was particularly low in women and elderly patients. Given the potential benefits of such tests, including more appropriate therapy and more objective monitoring of ventricular function, outcomes in persons with HF may be improved with more consistent use.