Prognostic role of echocardiography and brain natriuretic peptide in symptomatic breathless patients in the community
1 Department of Medicine, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92 019, Auckland, New Zealand
2 Department of General Practice and Community Health, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
3 Cardio-Endocrine Research Group, Christchurch School of Medicine and Health Sciences, The University of Otago, Christchurch, New Zealand
Received 5 December 2006; revised 7 November 2007; accepted 21 December 2007.
* Corresponding author. Tel: +64 9 373 7599 ext. 89813, Fax: +64 9 367 7146. Email: g.whalley{at}auckland.ac.nz
Aims: Brain natriuretic peptide (BNP), left ventricular (LV) systolic function, and mitral filling pattern (MFP) are prognostic indicators in patients with heart failure (HF). This study evaluated the potential role of E/Ea for predicting cardiovascular (CV) events in patients with suspected HF. This non-invasive measure of LV filling pressure has been shown to predict outcome in more advanced HF, but not in mild HF in the community.
Methods and results: Two hundred and twenty-eight elderly symptomatic general practice patients (dyspnoea/oedema) were recruited and underwent clinical evaluation, NT-proBNP assay, and comprehensive echocardiography. The Kaplan–Meier analysis of time to first CV hospitalization or CV death was performed for 1 year after presentation according to nominated thresholds of LV systolic function, NT-proBNP, MFP, and E/Ea ratio. Mean age was 70.3 ± 7.3 years, mean NT-proBNP was 111.4 ± 185.8, and 148 (65%) were female. Twenty-six patients (11%) experienced a CV event within 18 months of baseline (6 deaths and 20 admissions). Time to first CV event predicted by NT-proBNP (P < 0.0001), MFP (P = 0.009), and E:Ea (P = 0.0076), but not EF (P = 0.098). When NT-proBNP was elevated, E:Ea >15 identified a group of patients with lower survival (P < 0.0001).
Conclusion: Both E/Ea and NT-proBNP predicted hospitalization and when used in a two-step approach (NT-proBNP first, followed by E/Ea), the combination of both (elevated NT-proBNP and elevated E/Ea) identified those patients at highest risk, thus supporting a complementary approach for echocardiography and NT-proBNP in patients with HF symptoms.
Key Words: Echocardiography • Neurohormones • Diastole • Prognosis • Heart failure