Natriuretic peptide vs. clinical information for diagnosis of left ventricular systolic dysfunction in primary care.

BACKGROUND: Screening of primary care patients at risk for left ventricular systolic dysfunction by a simple blood-test might reduce referral rates for echocardiography. Whether or not natriuretic peptide testing is a useful and cost-effective diagnostic instrument in primary care settings, however, is still a matter of debate. METHODS: N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, clinical information, and echocardiographic data of left ventricular systolic function were collected in 542 family practice patients with at least one cardiovascular risk factor. We determined the diagnostic power of the NT-proBNP assessment in ruling out left ventricular systolic dysfunction and compared it to a risk score derived from a logistic regression model of easily acquired clinical information. RESULTS: 23 of 542 patients showed left ventricular systolic dysfunction. Both NT-proBNP and the clinical risk score consisting of dyspnea at exertion and ankle swelling, coronary artery disease and diuretic treatment showed excellent diagnostic power for ruling out left ventricular systolic dysfunction. AUC of NT-proBNP was 0.83 (95% CI, 0.75 to 0.92) with a sensitivity of 0.91 (95% CI, 0.71 to 0.98) and a specificity of 0.46 (95% CI, 0.41 to 0.50). AUC of the clinical risk score was 0.85 (95% CI, 0.79 to 0.91) with a sensitivity of 0.91 (95% CI, 0.71 to 0.98) and a specificity of 0.64 (95% CI, 0.59 to 0.67). 148 misclassifications using NT-proBNP and 55 using the clinical risk score revealed a significant difference (McNemar test; p < 0.001) that was based on the higher specificity of the clinical risk score. CONCLUSION: The evaluation of clinical information is at least as effective as NT-proBNP testing in ruling out left ventricular systolic dysfunction in family practice patients at risk. If these results are confirmed in larger cohorts and in different samples, family physicians should be encouraged to rely on the diagnostic power of the clinical information from their patients.

Impact of diabetes on left ventricular diastolic function in patients with arterial hypertension.

AIMS: To analyse the effect of diabetes (DM) on diastolic function in hypertensive patients. METHODS: 439 hypertensive patients were selected for participation in this study. All participants had an echocardiographic evaluation of systolic and diastolic function. The overall degree of diastolic function and specific parameters (e.g. E/Ea ratio) were analysed. RESULTS: We divided the cohort (63+/-10 years) into those with diabetes mellitus (DM(+), n=124) and without diabetes mellitus (DM(-), n=315). The prevalence of normal diastolic function was lower in DM(+) than DM(-) (19.4% vs. 30.8%); mild (65.3% vs. 60.0%) and moderate/ severe diastolic dysfunction were more frequent in DM(+) (15.3% vs. 9.2%, p=0.022). The E/Ea ratio, an estimate of left ventricular end-diastolic pressure, was significantly higher in DM(+) (12.3+/-4.4) as compared to DM(-) (10.8+/-3.6, p<0.001). Sex-specific analysis revealed that the effect of DM on diastolic function was mainly limited to the male subgroup. Multivariate logistic regression analysis showed that diabetes affected diastolic function in males independent of blood pressure, left ventricular mass index, concomitant medication and prevalence of coronary artery disease. CONCLUSION: Diabetes negatively affects diastolic function in patients with arterial hypertension. This effect is mainly confined to the male subgroup.

[Importance of surfactant proteins B and D for the differential diagnosis of acute dyspnea]. / Bedeutung der Surfactant-Proteine B und D in der Differentialdiagnostik der akuten Dyspnoe.

BACKGROUND AND PURPOSE: The basis for an optimal therapy of cardiopulmonary diseases is the assessment of an early diagnosis. This implies an evaluation of possible differential diagnoses of acute dyspnea. In numerous studies, natriuretic peptides were characterized as additional, meaningful parameters for the assessment of left ventricular function. Current studies could demonstrate that surfactant proteins B (SP-B) and D (SP-D) are of importance for the differentiation of patients with acute dyspnea. The aim of this study was to compare the values of NT-proBNP (N-terminal brain natriuretic peptide) and surfactant proteins for the assessment of a final diagnosis in patients with acute dyspnea. PATIENTS AND METHODS: NT-proBNP, SP-B and SP-D were measured in 81 patients with acute dyspnea in the emergency room and were correlated with clinical and echocardiographic parameters with respect to the final diagnosis. For this, patients were classified with respect to clinical and echocardiographic parameters in different subgroups concerning the final diagnosis of acute dyspnea. RESULTS: In patients with a cardiac origin of acute dyspnea, plasma levels of NT-proBNP were significantly higher as compared to patients with a noncardiac diagnosis (p = 0.04). SP-D was highest in patients with a cardiac origin of acute dyspnea, but after performing regression analysis it seems to be of less importance for the differential diagnosis of acute dyspnea as compared to NT-proBNP. SP-B plasma levels were not different between the four subgroups. CONCLUSION: NT-proBNP is of importance for the differential diagnosis of acute dyspnea. Although SP-D shows similar changes of plasma levels between the four subgroups, it seems to be of less importance for the differential diagnosis of acute dysnea. SP-B occurs to be of no relevance for the differentiation between cardiac and noncardiac origin of acute dyspnea.

Natriuretic peptides in the detection of preclinical diastolic or systolic dysfunction.

AIMS: The diagnostic value of natriuretic peptides in asymptomatic patients at risk for diastolic or systolic HF is controversial. We tested (1) the prevalence of preclinical LV dysfunction in an at-risk cohort; (2) the diagnostic accuracy of natriuretic peptides alone or in combination with clinical parameters for predicting asymptomatic left ventricular systolic or diastolic dysfunction. METHODS: 542 primary care patients (mean age 63 +/- 11 years, 42% female) without prediagnosed HF, but with risk factors for left ventricular dysfunction, underwent thorough cardiological workup, including echocardiography and analysis of natriuretic peptides. RESULTS: 23 patients (4%) showed reduced systolic function (EF < 50%), and 15 patients (3%) had severe diastolic dysfunction. All natriuretic peptides significantly increased with decreasing ejection fraction and with increasing degree of diastolic dysfunction. For natriuretic peptides, receiver operating characteristics analysis yielded good results for the detection of systolic dysfunction or severe diastolic dysfunction. Combining clinical parameters with natriuretic peptide data improved the diagnostic accuracy and largely reduced the number of needed screening echoes to identify patients with LV systolic or diastolic dysfunction. CONCLUSIONS: The prevalence of preclinical diastolic dysfunction is high in primary care patients at risk, but the relative prevalence of severe diastolic dysfunction and systolic dysfunction is only 7%. High-risk individuals may be screened most efficiently by using a score system incorporating clinical data and NT-proBNP.