Aortic Waveform Analysis to Individualize Treatment in Heart Failure

Abstract

Background: Afterload reduction is a cornerstone in the management of patients with heart failure (HF) and reduced ejection fraction. However, arterial load and the effect of HF therapies on afterload might vary between individuals. Tailoring vasoactive medicines to patients with HF based upon better understanding of arterial afterload may enable better individualization of therapy.

Methods and results: Subjects with HF and reduced ejection fraction underwent aggressive titration of vasoactive HF therapies with assessment of central aortic waveforms analyzed using pulse wave, wave separation, and arterial reservoir models. Clinical response to treatment was assessed using the 6-minute walk test distance, which increased in 25 subjects and decreased or remained unchanged in 13. Subjects with improvement on therapy displayed higher aortic pressure wave pulsatility (central pulse pressure [PP], reflected pressure wave, and reservoir pressure) at study entry compared with subjects without improvement (all P<0.05). Parameters derived by the arterial analysis methods were strongly correlated with one another and displayed similar ability to predict improvement. Aortic pressure pulsatility significantly decreased in subjects with functional improvement, whereas no change was observed in patients without functional improvement (P for interaction <0.05). These differences in arterial load at baseline and on therapy were not apparent from conventional brachial artery cuff pressure assessments.

Conclusions: Increased aortic pressure wave pulsatility and greater decrease in pulsatility on treatment are associated with functional improvement in patients with HF and reduced ejection fraction receiving aggressive vasodilator titration. These differences are not identifiable using brachial cuff pressures. Central aortic waveform analysis may enable better individualization of vasoactive therapies in chronic HF and reduced ejection fraction.

Clinical trial registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00588692.

Keywords: aorta; arterial pressure; blood pressure; heart failure; heart rate.

Conflict of interest statement

Disclosures: The data from this study was obtained in an investigator-initiated trial funded by AtCor Medical. The authors have no conflicts to disclose.

© 2017 American Heart Association, Inc.

Figures

Figure 1. Different aortic pulse models analyzed

[A] Pulse wave analysis, [B] Wave separation analysis, and [C] Arterial reservoir analysis. cSBP – central systolic blood pressure; DBP – diastolic blood pressure; AP – augmentation pressure; Tr – time to return of the reflected wave; ED – ejection duration, P1 – amplitude of the first systolic peak; P2 – amplitude of the second systolic peak, PP – pulse pressure (cSBP – DBP); Aix – augmentation index; Pf – forward pressure wave; Pb – reflected pressure wave; Pe – excess pressure; Pr-reservoir pressure

Figure 1. Different aortic pulse models analyzed

[A] Pulse wave analysis, [B] Wave separation analysis, and [C] Arterial reservoir analysis. cSBP – central systolic blood pressure; DBP – diastolic blood pressure; AP – augmentation pressure; Tr – time to return of the reflected wave; ED – ejection duration, P1 – amplitude of the first systolic peak; P2 – amplitude of the second systolic peak, PP – pulse pressure (cSBP – DBP); Aix – augmentation index; Pf – forward pressure wave; Pb – reflected pressure wave; Pe – excess pressure; Pr-reservoir pressure

Figure 1. Different aortic pulse models analyzed

[A] Pulse wave analysis, [B] Wave separation analysis, and [C] Arterial reservoir analysis. cSBP – central systolic blood pressure; DBP – diastolic blood pressure; AP – augmentation pressure; Tr – time to return of the reflected wave; ED – ejection duration, P1 – amplitude of the first systolic peak; P2 – amplitude of the second systolic peak, PP – pulse pressure (cSBP – DBP); Aix – augmentation index; Pf – forward pressure wave; Pb – reflected pressure wave; Pe – excess pressure; Pr-reservoir pressure

Figure 2. Changes in the 6-minute walk distance in relation to changes in peripheral and aortic waveforms

6m WD – 6-minte walking distance; bSBP – brachial systolic blood pressure; bPP – brachial pulse pressure; cPP-central pulse pressure; Pf – forward pressure wave; Pb – reflected pressure wave; Pr – reservoir pressure; * p

Figure 3

Association between reflected pressure change and 6 minute walk distance change

Figure 4. Individual response of the central pulse pressure (A), reflected pressure wave (B) and reservoir pressure (C) to hydralazine therapy

Red lines represent subjects without functional improvement, blue lines patients with functional improvement, dotted lines cut-off values of baseline value for functional improvement calculated by the ROC analysis. The functional status change associated with hydralazine therapy is dependent on baseline value and change in parameters of pressure wave pulsatility.