Ruling out heart failure in primary-care: the cost-benefit of pre-screening using NT-proBNP and QRS width.

BACKGROUND: Half of the patients presenting to primary-care with signs and symptoms of heart failure (HF) are found not to have serious heart disease after echocardiographic assessment. This places an unnecessary burden on hospital services. We sought to assess the cost-benefit of screening for left ventricular systolic dysfunction (LVSD) and major structural heart disease (SHD) using N-terminal pro-B-type natriuretic peptide (NT-proBNP) and QRS-width from an electrocardiogram in patients presenting with suspected HF to primary-care physicians (PCP).
METHODS: Patients were recruited from a community-based service pilot. Blood samples for NT-proBNP measurement were obtained in primary-care. All patients were referred irrespective of the NT-proBNP result, with echocardiograms reviewed by a cardiologist blinded to the NT-proBNP result.
RESULTS: NT-proBNP<180 pg/ml (21 pmol/l) 'ruled-out' major-LVSD avoiding 38% of echoes and 23% of cost compared with direct referral for echocardiography. NT-proBNP<93 pg/ml (11 pmol/l) 'ruled-out' major-SHD, avoiding 20% of echoes and 8% of cost. A QRS<84 ms 'ruled-out' major-LVSD, avoiding 28% of echoes and 17% of cost. A QRS<82 ms 'ruled-out' major-SHD avoiding 20% of echoes and 9% of cost. Intermediate values of NT-proBNP were often associated with equivocal echocardiography and in some scenarios NT-proBNP testing might avoid 61% of echocardiograms and 46% of cost.
CONCLUSION: Use of NT-proBNP by PCPs to detect major-LVSD and major-SHD in patients with suspected HF could reduce referrals for specialist HF-assessment, provide cost-avoidance compared to direct referral and improve the efficiency of care. QRS-width is less effective as a diagnostic test and adds little cost-benefit when combined with NT-proBNP.