In comparison to nonsmokers , the risk of recurrent VTAs was significantly higher in the total cohort of patients ( HR 1.54 ; 95 % CI 1.21-1 .95 ; P < .001 ) and in the subgroups of patients with ischemic and nonischemic cardiomyopathy ( HR 1.48 ; 95 % CI 1.03-2 .13 ; P = .035 ) .