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Tyumen
Cardiology
Research Center
www.infarkta.net
Mechanical dyssynchrony and super-response to cardiac resynchronisation
therapy in patients with congestive heart failure
625026 Tyumen, Melnikaite 111
• Background
Some patients with congestive heart failure (CHF) treated
with cardiac resynchronisation therapy (CRT) have greater
improvement of cardiac remodeling after CRT and they are
identified as super-responders. It remains unclear if
echocardiographic cardiac dyssynchrony parameters could
accurately predict super-response (SR) to CRT.
• Aim
To evaluate potential echocardiographic predictors related to SR
after CRT.
Kuznetsov V.A., Soldatova A.M., Krinochkin D.V., Melnikov N.N., Enina T.N.
• Results
LVEF
%
45
40
*
– р<0.05 between baseline
and postimplant level
35
30
25
ml
p<0.05
LVESV
180
* *
p<0.05
160
SR
non-SR
140
120
100
20
80
15
60
10
40
5
20
0
0
*
*
At baseline there were no difference in
clinical characteristics, atrial fibrillation
and left ventricular ejection fraction
(LVEF) among the groups. Both groups
demonstrated significant improvement in
NYHA functional class, reduction of LVEF
and LVESV (fig.1). Echocardiographic
parameters of mechanical dyssynchrony
were significantly higher in superresponders (tab.1).
• Materials and methods
Fig.1. Dynamics of LVEF and LVESV after 6 months of CRT
59 CRT patients (mean age 52.9±9.0 years, 88% men) with
Multiple
logistic
regression
analysis
showed
that
LVPEP
was
an
independent
predictor
for
CRT
SR
(95%
confidence
CHF (54% ischemic and 46% non-ischemic etiology) and IIinterval
[CI]
1.007–1.055;
p=0.011).
In
ROC
curve
analysis
LVPEP
demonstrated
sensitivity
73.7%
and
specificity
75%
III NYHA functional class were enrolled. After 6 months
(AUC
0.753;
p=0.002)
in
prediction
of
SR
to
CRT
(fig.2).
patients were divided into super-responders (reduction in left
ventricular end systolic volume (LVESV) >30%, n=20) and
Parameter
I group (n=20)
II group (n=39)
Р
9.53.4
7.54.4
0.05
non-super-responders (reduction of LVESV <30%, n=39). To
Systolic dyssynchrony index (%)
160.531.2
131.529.5
0.002
assess
mechanical
dyssynchrony
we
evaluated
LPEP (ms)
interventricular mechanical delay, duration of left ventricular
57.428.3
39.724.2
0.024
Interventricular mechanical delay
(ms)
pre-ejection period (LVPEP) by Doppler ultrasound velocity
57.841.0
35.338.5
0.05
Septal
to
lateral
wall
delay
(ms)
measurements of blood flow, the maximum delay between
110.266.1
71.657.9
0.038
Interventricular
delay
by
TDI
(ms)
peak systolic velocities of the septal and lateral walls of left
AUC=0,753,
p=0,002
88.445.3
67.742.8
NS
Intraventricular delay be TDI (ms)
ventricle by tissue Doppler imaging (TDI), systolic
dyssynchrony index was assessed by 3D echocardiography.
Fig.2. ROC-curve for sensitivity and specificity of LPEP in prediction of response to CRT
Table 1. Baseline parameters of mechanical dyssynchrony
• Discussion
CRT is an effective treatment for patients with CHF. Randomized controlled trials have demonstrated that CRT is associated with decreased heart failure symptoms, heart failure
hospitalization, and all-cause mortality. However approximately one-third of patients do not benefit from this therapy. In contrast some patients show greater improvement of the cardiac
function after CRT implantation and they are identified as “super-responders”. SR to CRT was first described in 2005. Still there is no single unified criteria of SR. Some authors defined
SR by an improvement in LVESV although different cut-offs were selected. In our study SR was defined as a relative reduction in LVESV >30% after 6 months of CRT according to
several large sample studies. Despite different response criteria in most studies patients with left bundle branch block (LBBB), non-ischaemic cardiomyopathy, absence of myocadial
2
infarction, normal left atrium size, body-mass index<30kg/m have the greatest benefit from CRT. In our study groups didn’t differ in QRS duration, presence of LBBB and other
parameters mentioned above. Both groups demonstrated significant improvement in NYHA functional class, decrease of LVESV, however improvement in LVEF and LVESV were
significantly higher in super-responders. In the present study the QRS duration and LBBB were not found to be predictive factors of greater response to CRT. The question about
utilization of mechanical dyssynchrony parameters to predict CRT response is still discussed. Some authors described TDI parameters as predictors of CRT response. PROSPECT-trial
sub-analysis showed that baseline level of electrical and mechanical dyssynchrony was significantly higher in super-responders. As in our study parameters of mechanical
dyssynchrony significantly differed between groups and greater mechanical dyssynchrony was associated with SR to CRT. In multivariate analysis LPEP was the only independent
.
factor associated with CRT SR. The proportion of super-responders in different studies is reported to be in the range of 12–47 %. The lack of a universal definition of SR to CRT is one of
the main reasons of such a wide range. The percentage of SR found in our study was 34%. Probable it can be explained by good patient selection with assessment of mechanical
dyssynchrony parameters by 2D and 3D echocardiography.
baseline
6 months
baseline
6 months
• Conclusion
Greater cardiac mechanical dyssynchrony is associated with SR to CRT in patients with CHF. LVPEP can be used as an independent predictor of CRT SR.
The authors have nothing to disclose.