A total of 282 patients with 300 APs (16 patients with two pathways and 1 patient with three pathways) were included.
Baseline historical characteristics and intra-procedural findings (apart from AP location) divided by sex and race are shown in . Whites were less commonly foreign-born and more commonly had a history of atrial fibrillation, but neither group otherwise differed by demographics or medical histories. Of the 39 foreign born patients, 15 were born in Latin America, 11 were born in East Asia, 8 were born in South and Southeast Asia, 2 were born in Europe, 1 was born in the Middle East, 1 was born in Africa and 1 was born in Fiji.
Historical characteristics and intra-procedural findings divided by sex (left) and by White versus not White (right). Age is displayed as median and (interquartile range).
There were no significant differences in intra-procedural findings by sex or race (). In addition, there were no differences by sex or race in antidromic or orthodromic AVRT cycle lengths.
Of the 17 patients with more than one AP, only one patient had pathways on different annuli. He was an Asian male and was the only patient with three APs (found in the left posterior, left inferoparaseptal, and right anterior locations). No patient had more than three APs.
Accessory Pathway Location by Sex
displays AP location by sex, with an overall statistically significant chi squared p value of 0.003. This overall statistically significant p value implies that at least one comparison was significant. Subsequent dichotomous comparisons revealed that this significant difference was driven primarily by males having a greater proportion of APs on the mitral annulus and females having a greater proportion on the tricuspid annulus. While the majority of all APs in males were in the left posterior location, the large majority of APs in females were on the tricuspid annulus ().
Proportions of accessory pathways in males and females in each location.
Proportions of males and females with at least one accessory pathway in a left posterior location or right annular location. P values represent comparisons denoted by brackets.
After adjusting for age and race, females had a 2.8 fold greater odds of having at least one right annular AP compared to males (95% confidence interval [CI] 1.70–4.65, p<0.001)
Accessory Pathway Location by Race
AP location by race is shown in . Among all races combined, the most common AP location was left posterior (129, or 43%, of 302 pathways). Although the overall chi squared p value was not significant across the individual comparisons, the most evident differences involved the proportions with right anterior APs. While right anterior pathways were rare in Whites, they were the second most common pathway in Asians. Although the number of Black subjects was small, the most common pathway in Blacks was a right anterior AP.
Proportions of accessory pathways by race in each location.
When AP location was dichotomized to right anterior versus all other locations, a significantly larger proportion of Asians had at least one right anterior AP compared to all other races combined (). Of note, consistent with the right versus left annular AP locations by sex, 11 out of 21 (52%) of Asian women had a right annular AP.
Proportions of Asians and all non-Asians with at least one right anterior accessory pathway. P values represent comparisons denoted by brackets.
Restricting the analysis to only those with data regarding self-identified race (excluding Latino ethnicity without a race designation and “Other” race), Whites were compared to Asians and Blacks: whereas 17 (10%) of Whites had a right anterior AP, 13 (27%) of Asians and Blacks combined had a pathway in this location (p=0.007).
After adjusting for sex and age, Asians continued to more commonly exhibit a right anterior AP (). Of note, after adjusting for the same potential confounders, the point estimate odds ratio for Blacks favored a right anterior pathway being more common than other races, but the 95% confidence interval crossed one (). In contrast, the point estimate odds ratio for Whites and Latinos were each less than 1.
Odds ratios of having at least one right anterior accessory pathway in Asian, White, Black and Latino patients compared to the rest of the population after adjusting for age and sex. Error bars denote 95% confidence intervals.
When foreign birth (birth outside North America) was added to the regression model, the association between Asian race and right anterior AP location was attenuated (OR 1.73, CI 0.44–6.77, p=0.43). This was explored by adjusting for specific region of birth, and the attenuation was found to be driven by a strong association between birth in East Asia (including China, n= 11, or Korea, n=1): those born in East Asia had an 18 fold greater odds of having at least one right anterior AP (95% CI 1.22–248.69, p=0.030). No other regions of birth were independently associated with a right anterior AP location.