Strong prognostic value of combining N-terminal atrial natriuretic peptide and ECG to predict death in heart patients from general practice

The relationship between long-term changes in plasma B-type natriuretic peptide levels and electrocardiographic findings

OBJECTIVES

Changes in B-type natriuretic peptide (BNP) and electrocardiographic (ECG) findings in an adult Japanese population were measured over a 5-year period, and the statistical relationships between these were evaluated.

METHODS

This was a longitudinal analysis in which data were collected on 353 subjects (135 men and 218 women) who had undergone general health checks in 1998 and 2003.

RESULTS

Data were examined by correlation coefficient and one-way analysis of covariance using repeated measurements. The correlation coefficient for BNP between 1998 and 2003 was 0.622 (P < 0.0001) for the men and 0.557 (P < 0.0001) for women. The changes in BNP over the same period were 13.71 +/- 26.06 (P < 0.0001) pg/ml in the men and 20.17 +/- 32.01 (P < 0.0001) pg/ml in the women. In 99 men and 145 women who had undergone ECG tests, with both normal and abnormal findings, visual inspections of changes in the ECG findings with respect to BNP changes were performed over the 5-year period. In men, both age and BNP significantly correlated with changes in ECG findings; however, in women, no significant correlation between BNP and changes in ECG findings was observed.

CONCLUSIONS

This regional longitudinal study revealed a gender difference in the relationship between long-term changes in BNP and ECG findings, suggesting that a 10 pg/ml or more increase in BNP in men over a 5-year period may a indicate worsening of cardiac function and the need for intervention.

Using BNP to develop a risk score for heart failure in primary care

AIMS

Chronic heart failure is a common condition with high mortality. Accurate diagnosis in primary care is difficult. Elevated B-type natriuretic peptide (BNP) is associated with left ventricular systolic dysfunction and increased mortality. Prognostic scoring systems using BNP may help to stratify risk in primary care patients. The aim of this research was to establish the independent variables which predict mortality in a primary care population-prescribed loop diuretics and to generate and validate a scoring system for heart failure in general practice.

METHODS AND RESULTS

Five hundred and thirty-two patients were followed up for a mean of 6.4 years after attending a research clinic for clinical assessment, electrocardiogram (ECG), echocardiography, and BNP. Multivariate analysis was used to establish independent prognostic variables and to generate a prognostic scoring system. The score generated was [0.50 x BNP+5 x age+50 x (CVA+sex+diabetes+ECG)]. The cut-off scores for risk groups were; 25th percentile, 411; 50th percentile, 475; 75th percentile, 524; Harrell's c=0.75.

CONCLUSION

Developing prognostic scoring systems provides a means of risk stratifying patients without relying on a single cut-off diagnostic value for BNP. Further validation of such scoring systems may improve future management of community heart failure patients.

The prognosis of impaired left ventricular systolic function and heart failure in a middle-aged and elderly population in an urban population segment of Copenhagen

AIMS

To determine the prognosis, total mortality and cardiac morbidity, of patients with left ventricular systolic dysfunction and heart failure (HF) in a general population sample.

METHODS AND RESULTS

A total of 764 subjects, 432 females and 332 males, median age (range) 66 years (50-89), participated in this cross sectional survey. The study population was recruited from randomly selected general practitioners and stratified to include a minimum of 150 persons in each age decade stratum. Each participant filled in a heart failure questionnaire and ECG, blood tests and echocardiography were performed. Median (range) follow-up was 1145 (51-1197) days. Subjects with LVEF < or = 0.40 had a significantly higher all-cause mortality (27.8% vs. 5.6%, P<0.0001), admission rate for HF (25.0% vs. 1.9%, P<0.0001) and for other cardiac causes (25.0% vs. 6.3%, P<0.0001) than in subjects with LVEF>0.40. The age and gender adjusted 2-year relative risk of death was 4.6 (95% C.I.=1.6-13.2). No significant difference in mortality was found between subjects with or without heart failure symptoms.

CONCLUSION

Significantly higher mortality as well as cardiac morbidity was found in subjects with symptomatic and asymptomatic LV systolic dysfunction compared to those with normal systolic function. These conditions were among the strongest predictors of all-cause mortality and cardiac morbidity.

Survival differences between heart failure in general practices and in hospitals

OBJECTIVES

To compare the survival of patients thought to have heart failure in general practice (GP-HF) with that of patients with heart failure in hospital (hospital-HF), patients with heart disease but without heart failure (non-HF), and a control group without heart disease.

DESIGN AND SETTING

Cross sectional study from general practice with a prospective follow up from 5.3 to 7.4 years.

PARTICIPANTS

2157 community participants, 1999 of whom lived outside nursing homes, were selected because they were registered with four general practitioners at entry. Study participants were divided into the four groups after a review of general practice case notes, questionnaires, and interviews.

MAIN OUTCOME MEASURES

Five year survival and multivariate predictors of all cause mortality.

RESULTS

Five year survival was 76% in the control group (n = 571, mean age at entry 74.1 years), 71% in non-HF patients (n = 218, 74.4 years), 61% in GP-HF patients (n = 67, 75.8 years), and 39% in hospital-HF patients (n = 33, 76.7 years). The median survival times were 6.8 years for GP-HF patients and 3.9 years for hospital-HF patients. Significant predictors of mortality in the multivariate Cox model of 1979 patients living outside nursing homes were hospital-HF (hazard ratio (HR) 2.1, p = 0.002), GP-HF (HR 1.7, p = 0.004), non-HF heart disease (HR 1.4, p = 0.03), previous myocardial infarction (HR 1.6, p = 0.04), no response to questionnaire (HR 2.0, p < 0.0001), higher age (for every 10 years, HR 2.4, p < 0.0001), and male sex (HR 2.1, p < 0.0001). Other factors such as atrial fibrillation, hypertension, and diabetes were not significant.

CONCLUSION

Heart failure in general practice is associated with a worse survival than that seen in the control group but is better than for patients who have been treated at least once for heart failure in a hospital.

The influence of age, sex and other variables on the plasma level of N-terminal pro brain natriuretic peptide in a large sample of the general population

OBJECTIVE

To identify potentially confounding variables for the interpretation of plasma N-terminal pro brain natriuretic peptide (NT-proBNP).

DESIGN

Randomly selected subjects filled in a heart failure questionnaire and underwent pulse and blood pressure measurements, ECG, echocardiography, and blood sampling.

SETTING

Subjects were recruited from four Copenhagen general practices located in the same urban area and were examined in a Copenhagen University Hospital.

PATIENTS

382 women and 290 men in four age groups: 50-59 years (n = 174); 60-69 years (n = 204); 70-79 years (n = 174); and > 80 years (n = 120).

MAIN OUTCOME MEASURES

Associations between the plasma concentration of NT-proBNP and a range of clinical variables.

RESULTS

In the undivided study sample, female sex (p < 0.0001), greater age (p < 0.0001), increasing dyspnoea (p = 0.0001), diabetes mellitus (p = 0.01), valvar heart disease (p = 0.002), low heart rate (p < 0.0001), left ventricular ejection fraction < or = 45% (p < 0.0001), abnormal ECG (p < 0.0001), high log10[plasma creatinine] (p = 0.0009), low log10[plasma glycosylated haemoglobin A1c] (p = 0.0004), and high log10[urine albumin] (p < 0.0001) were independently associated with a high plasma log10[plasma NT-proBNP] by multiple linear regression analysis.

CONCLUSIONS

A single reference interval for the normal value of NT-proBNP is unlikely to suffice. There are several confounders for the interpretation of a given NT-proBNP concentration and at the very least adjustment should be made for the independent effects of age and sex.

Retrospective analysis of the cost-effectiveness of using plasma brain natriuretic peptide in screening for left ventricular systolic dysfunction in the general population

OBJECTIVES

We sought to assess the cost-effectiveness of using plasma brain natriuretic peptide (BNP) as a pre-echocardiographic screening test for left ventricular systolic dysfunction (LVSD) in the general population.

BACKGROUND

We hypothesized that plasma BNP and simple clinical parameters would reduce the number of echocardiograms needed and cost when screening for LVSD in the general population.

METHODS

A random sample of 1,257 community subjects (age 25 to 74 years) was examined. Three risk groups were formed: one group with symptomatic ischemic heart disease (IHD); a second group with blood pressure >160/95 mm Hg and/or an abnormal electrocardiogram (high risk); and a group with none of these risk factors (low risk). The BNP assay was adjusted to give a high sensitivity.

RESULTS

Left ventricular systolic dysfunction was prevalent in 0.7% (6/823), 6% (16/269), and 19% (26/140) of low-risk and high-risk subjects and IHD subjects, respectively. Raised BNP concentrations (>8 pg/ml) occurred in 41%, 64%, and 71%. Sensitivities of BNP for detecting LVSD were 83% (5/6), 94% (15/16), and 92% (24/26); and the negative predictive values were 99.8%, 99.0%, and 95.1%. Brain natriuretic peptide was not associated with LVSD in low-risk subjects (p = 0.087), but in IHD subjects (p = 0.015) and high-risk subjects (p = 0.023). Screening high-risk subjects by BNP before echocardiography could have reduced the cost per detected case of LVSD by 26% for the cost ratio of 1/20 (BNP/echocardiogram).

CONCLUSIONS

Subjects at low and high risk of LVSD can be identified by simple clinical parameters, and BNP testing further reduces the number of echocardiograms needed and the costs of screening in subjects at risk <75 years of age in the general population.