[Incidence of ventricular arrhythmias in patients with severe left ventricular systolic dysfunction: is there a benefit after cardiac resynchronization therapy?].
BACKGROUND
Cardiac resynchronization therapy (CRT) has significant benefits in selected patients (P). The impact of this modality in the incidence of ventricular tachyarrhythmias remains controversial. We analysed the occurrence of appropriate therapies in P submitted to CRT combined with a cardioverter-defibrillator (ICD).


METHODS
Study of 123 P with left ventricular ejection fraction (LVEF) < 35%, submitted to successful implantation of CRT-ICD or ICD alone (primary prevention).


RESULTS
Mean age was 63 +/- 12 years, LVEF of 25 +/- 6%, median follow-up of 372 days. CRT-ICD implanted in 63P (group A) and ICD alone in 60P (group B). Group A has 86% of clinical responders, lower prevalence of ischemic cardiomyopathy (30% vs. 72%), and more P in class III of the NYHA before device implantation (90% vs. 7%) compared with ICD alone patients. There were no differences in the incidence of appropriate therapies (19% vs. 12%) or in the time for first therapy (305 days vs. 293 days). Total mortality was 11% in group A and 12% in group B. Kaplan-Meier curves for arrhythmic events in patients with CRT showed no significant differences (HR 3.02, 95% CI 0.82 - 11.09, p = NS) when compared to patients without CRT.


CONCLUSIONS
In P submitted to CRT-ICD for primary prevention, despite a higher rate of responders, the incidence of appropriate therapies is not different from those with an ICD alone.
Serviço de Cardiologia, Hospital de Santa Marta, CHLC EPE, Lisboa, Portugal. ana_timoteo@yahoo.com
Ana Teresa
AT
Timóteo
Mário Martins
MM
Oliveira
Manuel Nogueira
MN
Silva
Alexandra
A
Toste
Ruben
R
Ramos
Joana
J
Feliciano
Pedro Silva
PS
Cunha
Rui
R
Soares
Sofia
S
Santos
Rui Cruz
RC
Ferreira
D001145:Arrhythmias, Cardiac / Q000453:epidemiology* / Q000209:etiology / Q000628:therapy*; D058406:Cardiac Resynchronization Therapy; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013599:Systole; D018487:Ventricular Dysfunction, Left / Q000150:complications* / Q000628:therapy*