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Heart, Lung and Circulation Abstracts S652007;16:S1–S201

Conclusion: CR-BNP NT-proBNP measurements aretightly correlated with laboratory immunoassay E-BNPbut systematic differences exist.

doi:10.1016/j.hlc.2007.06.166

162The Optimal Timing of BNP Measurement after Exercise

J. Harris ∗, M.P. Feneley, C.S. Hayward

Cardiac Investigations and Echocardiography, St Vincent’sClinic, Sydney, NSW, Australia

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Conclusion: An acute rise in BNP was detected in 11 of12 patients post-exercise, evident at 5 min. This suggestssecretion of preformed stored NTproBNP. This informa-tion will be used in studies designed to detect a rise inLVEDP after exercise in an attempt to identify patientswith impaired diastolic function.

doi:10.1016/j.hlc.2007.06.167

163Monitoring of Antihypertensive Treatment for Left Ven-tricular Mass Regression

J. Hashimoto ∗, Y. Imai, M.F. O’Rourke

Tohoku University, Sendai, Japan; and St. Vincent’s Clinic, Dar-linghurst, New South Wales, Australia

Background: Pressure pulse waveform features may pre-dict treatment-induced regression of left ventricular (LV)mass better than casual brachial blood pressure (BP).We compared predictive power for LV mass reductionbetween the putative optimal pulse waveform feature(pulse amplification) and the putative optimal brachialcuff measurement (home BP measurement).Methods: Brachial BP was self-monitored at home in 43untreated patients with hypertension. Radial pressurewaveforms were recorded with tonometry in the clinicand transformed to aortic waveforms, and pulse amplifica-twbaR(BwidcpLBswβ

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ackground: B-type Natriuretic Peptide (BNP) is releasedy cardiac myocytes in response to increased left ventric-lar end diastolic pressure (LVEDP). Upregulation of BNProduction has been postulated to be the major determi-ant of BNP levels, however a small amount of BNP stored

n cardiac myocytes may be released acutely. The opti-al timing of BNP measurement post exercise is yet to

e identified.ethods: 19 patients (pts) underwent a Bruce protocol

xercise test. Point of care NT-proBNP (Roche Diagnostics)as assayed at rest, and 5, 20, and 60 min post-exercise.esults: NTproBNP (pg/mL) was below reading threshold

<60) in 7 pts. In the 11 pts in whom BNP increased, eleva-ion was evident 5 min. BNP decreased in 1. In the 12 ptsith valid results mean BNP (±SEM, heavy line) peaked atmin, p = 0.07 figure, (Rest 270 ± 86, 5 min 354 ± 128, 20 min45 ± 127, 60 min 341 ± 130).

ion (upper-limb pulse pressure ÷ central pulse pressure)as calculated. LV mass index (LVMI) was determinedy echocardiography. Examinations were repeated beforend after 1 year of standard medical treatment.esults: Antihypertensive treatment significantly

p < 0.001) reduced LV load, manifest by decrease in homeP and by increase in pulse amplification. These changesere accompanied by reduction in LVMI. However, for

ndividual patients, treatment-induced LVMI changeid not correlate with change in home BP (r < 0.05), butlosely correlated with change in amplification (r = 0.54,< 0.001). Amplification was a strong determinant ofVMI reduction, independent of age, gender and homeP. Estimated subject numbers required for predicting aignificant LVMI reduction were far less when the pulseaves were used rather than home BP; for α = 0.05 and= 0.20, numbers were 25 subjects for amplification butver 1000 for home BP.onclusion: Regression of LV mass is closely associatedith reduction in wave reflection, and can be assessedore precisely and easily from radial tonometry than from

he brachial cuff measurement, even in the home setting.

oi:10.1016/j.hlc.2007.06.168