Table 2.

Multivariate analysis: Risk factors for ACA/SCD among all patients with LQT1^*

	Relative risk
Risk factor	Hazard ratio	95% Confidence interval	P
Sex
Men vs women ≤ 13 y	2.31	1.41–3.92	.003
Men vs women >13 y	0.92	0.61–1.51	.72
Mutation location (vs nonmissense mutations)
Cytoplasmic loop (S2–S3/S4–S5 linkers)	1.93	1.37–2.75	.005
MS (S1, S2, S3, S4, S5, P-loop, S6)	1.02	0.71–1.85	.51
N/C terminus	0.96	0.52–1.57	.72
QTc duration (ms)
>550 vs <500	4.18	2.06–8.46	<.001
500–550 vs <500	3.35	1.83–6.11	<.001
Time-dependent syncope
Syncope vs no syncope	3.40	2.22–5.21	<.001

ACA = aborted cardiac arrest; LQT1 = long QT syndrome type 1; MS = membrane spanning; QTc = corrected QT interval; SCD = sudden cardiac death.

^*Models were further adjusted for missing QTc values, time-dependent beta-blocker therapy.