TY - JOUR
T1 - Upgrade and de novo cardiac resynchronization therapy
T2 - Impact of paced or intrinsic QRS morphology on outcomes and survival
AU - Wokhlu, Anita
AU - Rea, Robert F.
AU - Asirvatham, Samuel J.
AU - Webster, Tracy
AU - Brooke, Kelly
AU - Hodge, David O.
AU - Wiste, Heather J.
AU - Dong, Ying Xue
AU - Hayes, David L.
AU - Cha, Yong Mei
PY - 2009/10
Y1 - 2009/10
N2 - Background: Cardiac resynchronization therapy (CRT) improves outcomes in patients with left bundle branch block (LBBB), but the benefits of CRT in patients with other QRS morphologies or previous pacing are uncertain. Objective: The purpose of this study was to describe outcomes in patients with prior right ventricular pacing and non-LBBB morphologies. Methods: We studied 505 patients who underwent de novo CRT (n = 338) or CRT upgrade (n = 167). De novo patients were categorized by underlying QRS morphology: LBBB (67%), right bundle branch block (RBBB; 11%), intraventricular conduction delay (IVCD; 13%), and QRS <120 ms (9%). Upgrade patients were categorized by the percentage of previous ventricular pacing. Results: Patients were followed for death over a median of 2.6 years (interquartile range 1.6-4.0). New York Heart Association (NYHA) functional class and echocardiographic improvements were similar in de novo and upgrade patients. However, within the de novo group, NYHA improvements were less in patients with RBBB (0.3 ± 0.8; P = .014) or IVCD (0.2 ± 0.7; P = .001) than in those with LBBB (0.7 ± 0.8). These patients had less left ventricular functional improvement as well. Survival was comparable after de novo versus upgrade CRT (61% vs 63% at 4 years; P = .906). No clinical or survival differences were noted in upgrade patients based on the percentage of previous pacing. However, survival in de novo CRT recipients with RBBB (32%) was lower than in those with LBBB (66%; P <.001), and RBBB independently predicted death (hazard ratio 3.5, confidence interval 1.9-6.5; P <.001). Conclusion: RBBB and IVCD result in less clinical improvement or worsened survival after CRT. Additional selection criteria may be beneficial in identifying potential responders with RBBB, IVCD, or narrow QRS.
AB - Background: Cardiac resynchronization therapy (CRT) improves outcomes in patients with left bundle branch block (LBBB), but the benefits of CRT in patients with other QRS morphologies or previous pacing are uncertain. Objective: The purpose of this study was to describe outcomes in patients with prior right ventricular pacing and non-LBBB morphologies. Methods: We studied 505 patients who underwent de novo CRT (n = 338) or CRT upgrade (n = 167). De novo patients were categorized by underlying QRS morphology: LBBB (67%), right bundle branch block (RBBB; 11%), intraventricular conduction delay (IVCD; 13%), and QRS <120 ms (9%). Upgrade patients were categorized by the percentage of previous ventricular pacing. Results: Patients were followed for death over a median of 2.6 years (interquartile range 1.6-4.0). New York Heart Association (NYHA) functional class and echocardiographic improvements were similar in de novo and upgrade patients. However, within the de novo group, NYHA improvements were less in patients with RBBB (0.3 ± 0.8; P = .014) or IVCD (0.2 ± 0.7; P = .001) than in those with LBBB (0.7 ± 0.8). These patients had less left ventricular functional improvement as well. Survival was comparable after de novo versus upgrade CRT (61% vs 63% at 4 years; P = .906). No clinical or survival differences were noted in upgrade patients based on the percentage of previous pacing. However, survival in de novo CRT recipients with RBBB (32%) was lower than in those with LBBB (66%; P <.001), and RBBB independently predicted death (hazard ratio 3.5, confidence interval 1.9-6.5; P <.001). Conclusion: RBBB and IVCD result in less clinical improvement or worsened survival after CRT. Additional selection criteria may be beneficial in identifying potential responders with RBBB, IVCD, or narrow QRS.
KW - Biventricular pacing
KW - Cardiac resynchronization therapy
KW - Left bundle branch block
KW - QRS morphology
KW - Right bundle branch block
KW - Upgrade
KW - Ventricular pacing
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U2 - 10.1016/j.hrthm.2009.07.009
DO - 10.1016/j.hrthm.2009.07.009
M3 - Article
C2 - 19717348
AN - SCOPUS:77949530258
SN - 1547-5271
VL - 6
SP - 1439
EP - 1447
JO - Heart rhythm
JF - Heart rhythm
IS - 10
ER -