Prognostic implications of tissue Doppler in patients with dilated cardiomyopathy.
Previous studies have shown that a ratio of early transmitral flow velocity to early diastolic velocity of the mitral annulus (E/E') of > 15, obtained by tissue Doppler imaging (TDI), correlates with left ventricular filling pressure.


OBJECTIVE
The aim of our study was to assess whether E/E' provides prognostic information in patients with dilated cardiomyopathy.


METHODS
We studied 33 patients with dilated cardiomyopathy and mean ejection fraction of 31%. All the patients underwent routine two-dimensional and Doppler echocardiographic examination and TDI to determine early peak velocity of the mitral annulus. Pro-B-type natriuretic peptide (pro-BNP) and peak oxygen consumption (VO2max) were also measured. Patients were divided into two groups according to the value of E/E': Group I (n = 15 patients) with E/E' > or = 15 and Group II (n = 18 patients) with E/E' < 15. Patients were followed for 12+/-4 months; new hospital admission due to heart failure, heart transplantation and death were considered as cardiac events.


RESULTS
There were significant differences between the two groups in conventional two-dimensional echocardiographic measurements (dimensions and ejection fraction) and Doppler parameters (mitral inflow). With regard to mitral annular velocities obtained by TDI at two different points (septum and lateral wall), the E', A' and S' velocities differed significantly between the two groups, with lower velocities in Group I. Systolic velocity measured in the lateral portion of the mitral annulus showed the most significant difference: Group I - 4.46 cm/sec versus Group II - 7.19 cm/sec, p < 0.00001. Pro-BNP was 5622 pg/ml in Group I, and 1254 pg/ml in Group II, p = 0.004. VO2 max was significantly different between the two groups: Group I - 17.6 ml/kg/min versus Group II - 22.8 ml/kg/min, p = 0.004. During follow-up, events were more common in Group I, with 9 patients (60%) having events, while in Group II, the event rate was 11.1% (2 patients), p = 0.004.


CONCLUSIONS
The ratio of early transmitral flow velocity to early diastolic velocity of the mitral annulus is a powerful predictor of clinical outcome. Lower velocities of mitral annulus on TDI are expected in patients with E/E' > or = 15. Systolic velocities of under 5 cm/sec measured in the lateral portion of the mitral annulus appeared to be strongly related to prognosis.
Galrinho
Ana
A
Serviço de Cardiologia, Laboratório de Ecocardiografia, Hospital de Santa Marta, Lisboa, Portugal. anagalrinho@spc.pt
Branco
Luísa
L
Soares
Rui
R
Timóteo
Ana
A
Abreu
João
J
Leal
Ana
A
Silva
Sofia
S
Ferreira
Rui
R
D001783:Blood Flow Velocity; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging* / Q000503:physiopathology; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000503:physiopathology; D011379:Prognosis; D011446:Prospective Studies