[Influence of cardiopathy etiology on responses to cardiac resynchronization therapy].
OBJECTIVE
Little is known about how responses to cardiac resynchronization therapy (CRT) are affected by the nature of the underlying cardiopathy. The aim of this study was to investigate how cardiopathy etiology influences the effect of CRT on reverse left ventricular remodeling.


METHODS
The study included 106 patients with left ventricular systolic dysfunction and left bundle branch block (LBBB) who were receiving CRT. Clinical and echocardiographic investigations were performed at baseline before implantation and at 6 and 12 month follow-up to determine left ventricular diameter, volume and systolic function, and to quantify mitral regurgitation.


RESULTS
During follow-up, it was observed that CRT reduced left ventricular volume and diameter, increased left ventricular ejection fraction (LVEF), and reduced mitral regurgitation severity irrespective of the etiology of the cardiopathy. In patients with ischemic dilated cardiomyopathy, LVEF increased by 34% and end-diastolic and end-systolic volumes decreased by 4% and 12%, respectively; in those with idiopathic dilated cardiomyopathy, LVEF increased by 38% and end-diastolic and end-systolic volumes decreased by 13% and 19%, respectively (P=NS for ischemic vs. non-ischemic disease). Nor were differences observed between the groups in clinical outcome: 74% of the ischemic group responded compared with 62% of the non-ischemic group (P=NS).


CONCLUSIONS
At 12-month follow-up, patients with left ventricular systolic dysfunction and LBBB treated by CRT showed clinical improvements and demonstrated reverse ventricular remodeling, irrespective of the etiology of their cardiopathy.
Vidal
Bàrbara
B
Institut Clínic del Tòrax, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Barcelona, España.
Sitges
Marta
M
Delgado
Victoria
V
Mont
Lluís
L
Díaz-Infante
Ernesto
E
Azqueta
Manel
M
Paré
Carles
C
Tolosana
José M
JM
Berruezo
Antonio
A
Tamborero
David
D
Roig
Eulàlia
E
Brugada
Josep
J
D000368:Aged; D002037:Bundle-Branch Block / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D002304:Cardiac Pacing, Artificial; D002311:Cardiomyopathy, Dilated / Q000209:etiology; D004452:Echocardiography; D005260:Female; D006801:Humans; D008297:Male; D008944:Mitral Valve Insufficiency / Q000209:etiology; D011446:Prospective Studies; D013599:Systole; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D020257:Ventricular Remodeling / Q000502:physiology*