Is "hyper response" to cardiac resynchronization therapy in patients with nonischemic cardiomyopathy a recovery, a remission, or a control?
OBJECTIVE
Some patients treated by cardiac resynchronization therapy (CRT) recover "normal" left ventricular (LV) function and functional status. However, whether this "normalization" persists or reverts over time remains unknown. The aim of the present study was to evaluate the long-term outcomes of LV function in patients hyper responder to CRT.


METHODS
Eleven consecutive patients with nonischemic dilated cardiomyopathy, sinus rhythm, left bundle branch block (LBBB), New York Heart Association (NYHA) class III or IV, and optimal pharmacological treatment were hyper responder as they fulfilled concurrently the two following criteria: functional recovery (NYHA class I or II) and normalization of LV ejection fraction (LVEF).


RESULTS
After a mean follow-up of 65 ± 30 months between CRT implantation and last evaluation LVEF improved from 26 ± 9 to 59 ± 6% (P < 0.0001). One patient died from pulmonary embolism 31 months after implantation. Three patients exhibited LVEF ≤ 50% at their last follow-up visit (two at 40% and one at 45%). In eight patients, brief cessation of pacing was feasible (three were pacemaker-dependent). Mean QRS duration decreased from 181 ± 23 ms to 143 ± 22 ms (P = 0.006). In one patient, pacing was interrupted for 2 years and LVEF decreased markedly (from 65% to 31%) but returned to normal after a few months when pacing was resumed.


CONCLUSIONS
In hyper responder patients, "normalization" of LV function after CRT persists as long as pacing is maintained with an excellent survival.
Castellant
Philippe
P
Department of Cardiology, Hôpital de la Cavale Blanche, Brest University Hospital, Boulevard Tanguy Prigent, Brest Cedex, France.
Orhan
Erwann
E
Bertault-Valls
Valerie
V
Fatemi
Marjaneh
M
Etienne
Yves
Y
Blanc
Jean-Jacques
JJ
D000368:Aged; D002037:Bundle-Branch Block / Q000628:therapy; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D002311:Cardiomyopathy, Dilated / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011446:Prospective Studies; D020127:Recovery of Function; D012074:Remission Induction / Q000379:methods; D016019:Survival Analysis; D016896:Treatment Outcome; D016277:Ventricular Function, Left