Ahmet Fuat

Age-dependent values of N-terminal pro-B-type natriuretic peptide are superior to a single cut-point for ruling out suspected systolic dysfunction in primary care.

AIMSnThe study evaluated the use of age-related decision limits for N-terminal pro-B-type natriuretic peptide (NT-proBNP), for ruling out suspected systolic dysfunction in symptomatic patients in primary care, compared with the present standards.nnnMETHODS AND RESULTSnData were obtained from 5508 patients from 10 studies in the UK, New Zealand, Europe, and USA. All have had NT-proBNP analysis and echocardiography. The median age was 62 years (range 18-100 years) with a prevalence of reduced left ventricular systolic function (left ventricular ejection fraction < or =40%) of 18%. In a receiver operating characteristic curve analysis, overall area under the curve (AUC) was 0.89. When looking at different age groups, AUC was highest (0.95) for <50 years, intermediate (0.90) for 50-75 years, and lowest (0.82) for >75 years. Using optimized decision limits, sensitivity, specificity, and negative predictive values (NPVs) were: <50 years (50 ng/L): 99.2, 57.2, and 99.7%; 50-75 years (75 ng/L): 95.9, 51.0, and 96.8%; and >75 years (250 ng/L): 87.9, 53.7, and 92.4%, respectively. Using only a single decision value (125 ng/L for all ages) gave sensitivities of 89.1, 91.9, and 94.3%; specificities of 84.0, 69.1, and 29.3% and NPVs of 97.7, 97.6, and 93.4%. A decision value of 400 ng/L for all ages gave much lower sensitivities.nnnCONCLUSIONnIn a large population of patients in primary care, the use of age-stratified NT-proBNP decision limits considerably improves performance over current standards, with an excellent NPV for exclusion of reduced left ventricular systolic function.

Diagnostic triage and the role of natriuretic peptide testing and echocardiography for suspected heart failure: an appropriateness ratings evaluation by UK GPs

BACKGROUNDnSome UK GPs are acquiring access to natriuretic peptide (NP) testing or echocardiography as diagnostic tests for heart failure. This study developed appropriateness ratings for the diagnostic application of these tests in routine general practice.nnnAIMnTo develop appropriateness ratings for the diagnostic application of NP testing or echocardiography for heart failure in general practice.nnnDESIGN AND SETTINGnAn appropriateness ratings evaluation in UK general practice.nnnMETHODnFour presenting symptoms (cough, bilateral ankle swelling, dyspnoea, fatigue), three levels of risk of cardiovascular disease (low, intermediate, high), and dichotomous categorisations of cardiovascular/chest examination and electrocardiogram result, were used to create 540 appropriateness scenarios for patients in whom NP testing or echocardiography might be considered. These were rated by a 10-person expert panel, consisting of GPs and GPs with specialist interests in cardiology, in a two-round RAND Appropriateness Method.nnnRESULTSnOnward referral for NP testing or echocardiography was rated as an appropriate next step in 217 (40.2%) of the 540 scenarios; in 194 (35.9%) it was rated inappropriate. The ratings also show where NP testing or echocardiography were ranked as equivalent next steps and when one test was seen as the more appropriate than the other.nnnCONCLUSIONnNP testing should be the routine test for suspected heart failure where referral for diagnostic testing is considered appropriate. An abnormal electrocardiogram status makes referral to echocardiography an accompanying, or more appropriate, next step alongside NP testing, especially in the presence of dyspnoea. Abnormal NP testing should subsequently be followed up with referral for echocardiography.