Bedside B-type natriuretic peptide test aids dyspnoea diagnosis in the elderly

A 15-minute bedside test for B-natriuretic peptide (BNP) assists diagnosis of dyspnoea in elderly patients presenting to hospital with dyspnoea, particularly in establishing the likelihood of heart failure, a Swiss study has found.The study investigated 269 patients with an average age of 80 (range 70-97). They were randomly assigned to have the BNP test as part of their initial emergency department work-up, or to not have the test. Results were classified as lower than 100 pg/ml (in which case heart failure was unlikely and alternative diagnoses had to be pursued) or higher than 500 pg/ml (heart failure was considered likely and rapid therapy with diuretics, nitroglycerine, ACE inhibitors and morphine was recommended). In the intermediate group the study protocol recommended clinical judgment and further testing.Heart failure was the most common diagnosis, followed by COPD and pneumonia. Patients assigned to BNP testing had a shorter hospital stay (9 vs 11 days), lower total treatment costs and a significant reduction in 30-day mortality (9% vs 17%). "Used in conjunction with other clinical information, rapid measurement of BNP in the emergency department improved the management of elderly patients presenting with dyspnoea," the study concluded.Heart failure was one of the most common causes of hospital admission in the elderly but the differential diagnosis was difficult because of factors such as extensive comorbidity, poor renal function and preserved left ventricular systolic function. "Misdiagnosis of heart failure causes morbidity and increases time to discharge and treatment cost, because treatments for heart failure may be hazardous to patients with other conditions such as chronic obstructive lung disease and vice versa," the report stated. BNP, a novel cardiac marker, was reliably elevated in heart failure, less so in left ventricular diastolic than systolic dysfunction, and its exact role in the elderly had not been determined.Reference...