Table 6.

Interactions of ECG parameters with ICD effect in propensity score-adjusted Cox regressions for all-cause mortality

	Stratified by propensity score quintiles (n = 2073)			2:1 matching (n = 1398)
	HR	95% CI	P-value	HR	95% CI	P-value
ICD effect (ICD vs. control)	0.69	0.53–0.90	<0.01	0.70	0.54–0.92	0.01
Interaction with ICD effect	HR interaction	95% CI	P-value	HR interaction	95% CI	P-value
QTc	0.99	0.98–1.00	<0.01	0.99	0.90–1.00	0.02
Heart rate (b.p.m.)	1.01	1.00–1.03	0.09	1.01	1.00–1.03	0.16
QRSd (ms)	1.00	0.99–1.01	0.52	1.00	0.99–1.01	0.70
ER_lat (yes vs. no)a	–	–	–	–	–	–
Q_tot (yes vs. no)	0.35	0.18–0.69	<0.01	0.44	0.21–0.93	0.03
Q_ant (yes vs. no)	0.29	0.13–0.69	0.01	0.37	0.14–0.96	0.04
Tinv_lat (yes vs. no)	0.61	0.35–1.08	0.09	0.92	0.48–1.73	0.79
Q_lat (yes vs. no)	0.33	0.08–1.44	0.14	0.39	0.08–2.00	0.26
fQRS_tot (yes vs. no)	1.32	0.80–2.17	0.27	1.35	0.77–2.35	0.30
QRS120 (yes vs. no)	0.79	0.49–1.28	0.34	0.81	0.47–1.39	0.44
QTc 450/470 (yes vs. no)	0.79	0.49–1.29	0.35	0.91	0.53–1.57	0.74
IVCD (yes vs. no)	0.79	0.47–1.35	0.40	0.85	0.47–1.54	0.60
fQRS_ant (yes vs. no)	0.69	0.29–1.65	0.40	1.44	0.52–3.99	0.48
ER_tot (yes vs. no)	0.70	0.30–1.64	0.42	0.69	0.27–1.80	0.45
Sinus rhythm (yes vs. no)	0.80	0.44–1.45	0.46	1.14	0.59–2.23	0.70
fQRS_lat (yes vs. no)	1.23	0.70–2.16	0.47	0.88	0.47–1.66	0.70
ER_inf (yes vs. no)	0.74	0.31–1.79	0.51	0.68	0.47–1.55	0.45
Tinv_inf (yes vs. no)	0.87	0.51–1.51	0.63	0.86	0.47–1.55	0.61
Q_inf (yes vs. no)	1.68	0.20–13.81	0.63	2.04	0.23–17.73	0.52
Tinv_tot (yes vs. no)	0.88	0.53–1.46	0.63	1.07	0.61–1.88	0.82
Tinv_ant (yes vs. no)	0.92	0.56–1.49	0.72	0.99	0.57–1.69	0.96
LBBB (yes vs. no)	0.88	0.26–2.97	0.84	0.75	0.20–2.88	0.68
RBBB (yes vs. no)	0.94	0.44–2.04	0.88	0.93	0.38–2.25	0.87

Statistically significant results presented in bold.

95% CI, 95% confidence interval; ant, anterior; ECG, electrocardiogram; ER, early repolarization; fQRS, QRS-complex fragmentation; HR, hazard ratio; ICD, implantable cardioverter-defibrillator; inf, inferior; IVCD, non-specific intraventricular conduction delay; lat, lateral; LBBB, left bundle brunch block; Q, pathological Q wave; QRS120, QRS duration ≥120 ms (1) or less 0; QRSd, QRS duration; QTc 450/470, QTc ≥450 ms in male and ≥470 ms in female (1) or less 0; QTc, QT-interval corrected by Framingham’s formula; RBBB, right bundle branch block; Tinv, T-wave inversion; tot, total.

^aAll ICD patients with lateral ER (N = 69) survived the follow-up time.