European Journal of Echocardiography Advance Access published online on June 18, 2008
European Journal of Echocardiography, doi:10.1093/ejechocard/jen184
Ventricular-arterial coupling in patients with heart failure treated with cardiac resynchronization therapy: may we predict the long-term clinical response?
1 Division of Cardiology, General Hospital, Rovigo, Italy
2 Medtronic Italia, Sesto San Giovanni, Italy
Received 21 January 2008; accepted after revision 25 May 2008.
* Corresponding author. Tel: +39 0425 394252; fax: +39 0425 393597. E-mail address: franc.zanon{at}iol.it
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Abstract |
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Objective: To evaluate the effects of cardiac resynchronization therapy (CRT) on ventricular-arterial coupling (VAC) in patients with refractory congestive heart failure (HF), left bundle brunch block, and sinus rhythm.
Background: The ratio between arterial elastance (Ea) and left ventricular end-systolic elastance (Ees), the so-called VAC, defines the efficiency of the myocardium in pumping blood.
Methods: Seventy-eight patients were studied with echocardiography before CRT, and 1 year later. End-systolic elastance was calculated according to the method of Chen. Arterial elastance (ratio of the systolic pressure to the stroke volume), end-systolic volume (ESV), and quality of life (QoL) (Minnesota Living with Heart Failure Questionnaire) were assessed at the baseline and after 1 year. Patients with a reduction >15% of ESV or a decrease >33% in QoL score were considered responders to CRT.
Results: QRS duration and interventricular delay were significantly reduced with CRT compared with baseline (156 ± 2 vs. 195 ± 3 ms, P < 0.001; and 25 ± 2 vs. 55 ± 3 ms, P < 0.001, respectively). Arterial elastance/Ees decreased significantly on CRT (2.47 ± 1.48 vs. 1.41 ± 0.87, P < 0.0001). The lowering of Ea/Ees was congruent to a decrease in intraventricular delay (83.1 ± 55.7 vs. 28.4 ± 49.5 ms, P < 0.0001) and an increase in ejection fraction (26 ± 6.3 vs. 36.9 ± 8.0%, P < 0.0001). Responders to CRT were 74 and 71% of the overall patient population, considering as endpoint QoL or ESV, respectively. The analysis of VAC showed a baseline cut-off value of 2, above which 88% and 69% of patients responded to CRT, considering as endpoint QoL or ESV, respectively.
Conclusions: The non-invasive assessment of VAC may be proposed as an immediate, easy, and optimal tool for quantifying the effect of CRT in patients with HF.
Keywords: Cardiac resynchronization therapy; Ventricular arterial coupling; Quality of life