3.3. Risk of SSS
A total of 115 patients with incident AF developed SSS during the follow-up period of 35,086 person-years, whereas among those without AF, 431 participants developed SSS. The incidence of SSS was 3.4 and 0.2 per 1000 person-years in the AF and PS-matched patients without AF, respectively (Table 2). Patients with AF had a higher cumulative incidence of SSS compared to the overall (log-rank p<0.001, Figure 3A) and PS-matched patients without AF (log-rank p<0.001, Figure 3B). After adjustment of clinical variables and competing risk of mortality, the subjects with incident AF had an increased risk of SSS with adjusted hazard ratio (HR) of 8.2 (95% CI: 6.5–10.3). After PS matching, incident AF was associated with significantly increased risk of SSS with adjusted HR of 13.4 (95% CI: 8.4–21.4) (Table 2).
The analysis of censoring for heart failure was performed in patients without history of heart failure (incident AF, 10,706; no-AF, 265,865). During the follow-up period, heart failure occurred in 13.2% and 1.4% patients in the AF and no-AF groups, respectively. After censoring for heart failure, the incidence of SSS was 2.7 and 0.2 per 1000 person-years in the AF and PS-matched no-AF groups, respectively (Table 2). The incident AF group had a higher cumulative incidence of SSS compared to the overall (log-rank p<0.001; Figure 3C) and PS-matched patients without AF (log-rank p<0.001; Figure 3D). After adjustment for clinical variables and competing risk of mortality, incident AF was associated with an increased risk of SSS (adjusted HR, 11.4; 95% CI: 8.7–14.9). After PS matching, compared with PS-matched no-AF group, incident AF was associated with increased the risk of SSS with adjusted HR of 16.0 (95% CI: 9.2–28.0) (Table 2).
After censoring for heart failure or acute myocardial infarction, incident AF had increased risk of SSS compared to the overall (adjusted HR, 11.6; 95% CI: 8.9–15.2) and PS-matched groups (adjusted HR, 16.9; 95% CI: 9.3–29.7) (Table 2).
In subgroup analysis, incident AF increased the risk of SSS regardless of sex, age, living in metropolitan cities, economic status, heart failure, hypertension, diabetes, ischemic stroke/transient ischemic attack, vascular disease, CHA2DS2-VASc score, medication for rate control, and antiarrhythmic drugs (Figure 4).