Efficiency, reproducibility and agreement of five different hemodynamic measures for optimization of cardiac resynchronization therapy ☆ Zachary I. Whinnett ⁎ , Justin E.R. Davies, Gemma Nott, Keith Willson, Charlotte H. Manisty, Nicholas S. Peters, Prapa Kanagaratnam, D. Wyn Davies, Alun D. Hughes, Jamil Mayet, Darrel P. Francis International Centre for Circulatory Health, St Mary's Hospital and Imperial College, 59-61 North Wharf Road, W2 1LA, London, United Kingdom Received 2 December 2006; received in revised form 28 June 2007; accepted 3 August 2007 Available online 18 September 2007 Abstract Background: Several hemodynamic measures have been used for optimization of the AV delay of cardiac resynchronization therapy (CRT), including pulse pressure (PP), systolic blood pressure (SBP) and cardiac output (CO). We aimed to determine whether these measures identify the same optimum and whether they have the same efficiency and reproducibility at identifying this optimum. Methods and results: In 22 patients with cardiac resynchronization therapy, we adjusted the AV delay while atrially pacing at 110 bpm and simultaneously recording SBP, diastolic blood pressure (DBP), PP, mean arterial pressure (MAP) and CO. SBP, PP and CO all had essentially the same signal-to-noise ratios (15.4 ± 5.4, 15.5 ± 6.4, 15.3 ± 7.4 respectively p = NS). In contrast, MAP and DBP had significantly worse signal-to-noise ratios than SBP (14.2 ± 5.6, p = 0.003 and 12.1 ± 4.4, p b 0.0001 respectively). The optimal AV delay was very similar between SBP, PP, MAP and DBP. For example, the optima identified by SBP correlated strongly with those identified by PP (r = 0.94), MAP (r = 0.96) and DBP (r = 0.90). In contrast, the optima detected by CO was poorly related to these (e.g. r =0.36 with SBP optima). Reproducibility was best for optima detected by SBP followed by MAP and PP. Conclusions: Essentially the same AVoptimum is identified, regardless of whether the parameter chosen for maximization is SBP, PP, MAP or DBP. We conclude that optimizing the CRTAV delay using SBP gives the best combination of efficiency and reproducibility, with PP and MAP being reasonable alternatives. © 2007 Elsevier Ireland Ltd. All rights reserved. Keywords: Atrioventricular delay optimization; Cardiac resynchronization therapy; Finometer; Hemodynamic optimization 1. Introduction Cardiac resynchronization therapy improves hemody- namic status [1–8]. Additional hemodynamic improvements can be obtained by selecting the appropriate atrioventricular delay (AV) [9,7,10,11] and interventricular delay [5,12,13] for an individual patient. A number of different hemodynamic markers have been used to guide this optimization process. These include systolic blood pressure (SBP) [11], pulse pressure (PP) [9], mean atrial pressure (MAP) and cardiac output (CO). However, it is unclear whether all of these measures give comparable results when they are used for AV delay optimization both in terms of signal quality, the delay identified as providing the maximal hemodynamic response and reproducibility. This information is potentially important when selecting which hemodynamic parameter to use in clinical practice and when designing studies assessing the effect of optimization on clinical outcome measures. It is possible to acquire these hemodynamic measures non- invasively using the Finometer device (Finapres Medical International Journal of Cardiology 129 (2008) 216 – 226 www.elsevier.com/locate/ijcard ☆ Conflict of interests' disclosures: Dr Whinnett (FS/05/068), Dr Davies (FS/05/006) and Dr Francis (FS/04/079) are supported by fellowships from the British Heart Foundation. Dr Manisty (077049/Z/05/Z) is funded by the Wellcome Trust. Our institution has filed a patent on some of the methods described in this manuscript. ⁎ Corresponding author. Tel.: +44 20 7594 1263; fax: +44 20 7594 1706. E-mail address: zacharywhinnett@yahoo.com (Z.I. Whinnett). 0167-5273/$ - see front matter © 2007 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijcard.2007.08.004