Race and Sex Differences in QRS Interval and Associated Outcome Among Patients With Left Ventricular Systolic Dysfunction

Background-prolonged qrs duration is associated with increased mortality among heart failure patients,but race or sex differences in qrs duration and associated effect on outcomes are unknown. methods and results--we investigated qrs duration and morphology among 2463 black and white patients with heart failure and left ventricular ejection fraction ≤35% who underwent coronary angiography and 12-lead electrocardiography at duke university hospital from 1995 through 2011. we used multivariable cox regression models to assess the relationship between qrs duration and all-cause mortality and investigate race-qrs and sex-qrs duration interaction. median qrs duration was 105 ms (interquartile range [iqr],92-132) with variation by race and sex (p<0.001). qrs duration was longest in white men (111 ms; iqr,98-139) followed by white women (108 ms; iqr,92-140),black men (100 ms; iqr,91-120),and black women (94 ms; iqr,86-118). left bundle branch block was more common in women than men (24% vs 14%) and in white (21%) versus black individuals (12%). in black patients,there was a 16% increase in risk of mortality for every 10 ms increase in qrs duration up to 112 ms (hazard ratio,1.16; 95% ci,1.07,1.25) that was not present among white patients (interaction,p=0.06). conclusions--black individuals with heart failure had a shorter qrs duration and more often had non-left bundle branch block morphology than white patients. women had left bundle branch block more commonly than men. among black patients,modest qrs prolongation was associated with increased mortality. © 2017 the authors.