Table 3.

Cox regression analysis of the impact of QTc by 10 ms increase on risk of early (≤60 years) and late (>60years) AF among the carriers of LQT1 and LQT3 mutation carriers and genotype-negative control subjects. (adjusted for gender and time-dependent beta blocker therapy). Interaction p-value LQT1 vs LQT3: p=0.020 for Age≤60 years and p=0.018 for Age>60 years. Interaction between the LQTS genotypes and the control group are not significant in either of the age intervals.

	Age ≤60 years			Age >60 years
	HR	95%CI	p-value	HR	95%CI	p-value
LQT1	1.03	0.90–1.17	0.674	1.01	0.90–1.13	0.835
LQT3	0.82	0.72–0.94	0.004	0.75	0.61–0.93	0.010
Control	0.90	0.70–1.16	0.415	0.92	0.80–1.06	0.231