Combined electrical and global markers of dyssynchrony predict clinical response to Cardiac Resynchronization Therapy

Figures & data

Figure 1. Schematic presentation of LV filling and ejection spectral Doppler showing how global markers of dyssynchrony, that is, total isovolumic time (t-IVT), Tei index and LV–RV pre-ejection times, are measured. LV: left ventricle; RV: right ventricle; HR: heart rate; ET: ejection time; FT: filling time; IVCT: isovolumic contraction time; IVRT: isovolumic relaxation time.

Table I. Clinical and echocardiography data in study patients and in study groups.

Variable	All (n = 103)	Responders (n = 61)	Non-responders (n = 42)	P
Age (years)	67 ± 12	67 ± 12	68 ± 12	0.54
% female	18	20	14	0.61
Heart rate (beats/min)	74 ± 16	76 ± 14	71 ± 15	0.07
QRS duration (ms)	152 ± 12	158 ± 12	145 ± 11	0.01
NT-pro-BNP (pg/ml)	4491 ± 4602	4414 ± 4082	4602 ± 5336	0.88
Atrial fibrillation (%)	26	21	33	0.18
Left atrium (mm)	51 ± 8	50 ± 8	52 ± 9	0.24
LV EDD (mm)	70 ± 9	70 ± 9	70 ± 10	0.91
LV ESD (mm)	61 ± 9	61 ± 8	61 ± 10	0.92
LV EF (%)	26 ± 6.5	25 ± 7	26 ± 7	0.28
E wave (cm/s)	89 ± 30	90 ± 29	89 ± 31	0.84
A wave (cm/s)	57 ± 27	61 ± 29	52 ± 22	0.13
E/A ratio	1.9 ± 1.2	1.85 ± 1.2	2.1 ± 1.3	0.48
E wave deceleration time (ms)	171 ± 59	167 ± 60	176 ± 58	0.47
Restrictive filling pattern (%)	34	31	38	0.53
t-IVT (s/min)	13 ± 5	14.5 ± 6	11 ± 5	0.001
Tei index	0.7 ± 0.3	0.78 ± 0.4	0.63 ± 0.2	0.01
LV–RV pre-ejection time (ms)	29 ± 34	32 ± 36	26 ± 29	0.56
MAPSE septal (cm)	0.7 ± 0.2	0.71 ± 0.2	0.74 ± 0.2	0.51
MAPSE lateral (cm)	1 ± 0.3	1 ± 0.2	1 ± 0.3	0.75
TAPSE (cm)	1.8 ± 0.5	1.8 ± 0.5	1.7 ± 0.4	0.28
Stroke volume (ml)	65 ± 23	64 ± 23	67 ± 23	0.53
Tricuspid regurgitation pressure drop (mmHg)	37 ± 10	35 ± 11	39 ± 9	0.03

LV, left ventricle; RV, right ventricle; A, atrial diastolic velocity; E, early diastolic filling velocity; EDD, end-diastolic dimension; ESD, end-systolic dimension; T-IVT, total isovolumic time; IVRT, isovolumic relaxation time.

Table II. Predictors of CRT non-responders in all patients.

Variable	Odds ratio (95% CI)	P value
Multivariate predictors
T-IVT (s/min)	0.878 (0.802–0.962)	0.005
QRS duration (ms)	0.978 (0.960–0.996)	0.019
Tricuspid regurgitation pressure drop (mmHg)	1.047 (1.001–1.096)	0.046
Age (years)	1.021 (0.981–1.063)	0.298
Gender (%, male)	0.564 (0.163–1.946)	0.365

T-IVT, total isovolumic time; MAPSE, mitral annular plane systolic excursion; TAPSE, tricuspid annular plane systolic excursion.

Figure 2. ROC curve showing the highest specificity of combined QRS duration and t-IVT, in predicting CRT non-responders.

Table III. Predictors of CRT non-responders in atrial fibrillation patients.

Variable	Odds ratio (95% CI)	P value
Multivariate predictors
T-IVT (s/min)	0.745 (0.547–0.968)	0.03
QRS duration (ms)	0.983 (0.946–1.022)	0.39
Tricuspid regurgitation pressure drop (mmHg)	0.976 (0.870–1.095)	0.68
Age (years)	1.065 (0.910–1.247)	0.43
Gender (%, male)	0.073 (0.004–1.377)	0.08

T-IVT, total isovolumic time.