Table 3.

Univariable Analyses of Predictors of Clinical Outcomes After CRT

	Cardiac Mortality				Total Mortality				Total Mortality or HF Hospitalization				Total Mortality or MACE				SCD, VT/VF or Shock
	HR	95% CI		P Value	HR	95% CI		P Value	HR	95% CI		P Value	HR	95% CI		P Value	HR	95% CI		P Value
Pre‐CRT
QRSarea (≥102 μVs)	0.33	0.19	0.57	<0.001	0.50	0.33	0.76	<0.001	0.43	0.28	0.65	<0.001	0.39	0.26	0.59	<0.001	0.50	0.25	0.98	0.042
QRSd (≥150 ms)	0.37	0.22	0.64	<0.001	0.60	0.39	0.92	0.018	0.60	0.40	0.91	0.016	0.53	0.35	0.80	0.002	0.38	0.19	0.75	0.006
LBBB	0.80	0.47	1.36	0.408	0.75	0.49	1.15	0.192	0.67	0.44	1.02	0.061	0.82	0.54	1.25	0.355	0.69	0.36	1.31	0.251
Post‐CRT
ΔQRSarea, μVs	1.02	1.01	1.02	<0.001	1.01	1.01	1.01	<0.001	1.01	1.01	1.01	<0.001	1.01	1.01	1.01	<0.001	1.01	1.01	1.02	0.003
QRSarea reduction ≥45 μVs	0.19	0.10	0.36	<0.001	0.45	0.31	0.65	<0.001	0.44	0.32	0.61	<0.001	0.43	0.31	0.58	<0.001	0.26	0.11	0.58	0.001
ΔQRSd, ms	1.02	1.01	1.03	<0.001	1.01	1.01	1.02	<0.001	1.01	1.01	1.02	<0.001	1.01	1.02	1.02	<0.001	1.01	1.01	1.03	0.003
QRSd reductiona	0.23	0.14	0.39	<0.001	0.48	0.34	0.68	<0.001	0.48	0.35	0.65	<0.001	0.51	0.38	0.68	<0.001	0.33	0.17	0.67	0.018

Results of univariate Cox proportional hazards models, expressed as hazard ratio (HR) and 95% CI, for QRS area (QRS_area) and QRS duration (QRSd) using specified cutoffs (in parentheses), and for QRS morphology (LBBB). Results of analyses using continuous and dichotomous variables are shown. CRT indicates cardiac resynchronization therapy; HF, heart failure; LBBB, left bundle branch block; MACE, major adverse cardiac events; SCD, sudden cardiac death; VF, ventricular fibrillation; VT, ventricular tachycardia.

^aRefers to any QRSd reduction below baseline.