Intermediate pause at daytime is associated with increased cardiovascular risk and mortality: An 8-year cohort study

Background--Long-term cardiovascular risk in patients with intermediate pauses remains unclear. Whether asymptomatic patients with intermediate pauses have increased future cardiovascular events remains unknown. We hypothesize that intermediate pause is associated with increased cardiovascular risk and mortality. Methods and Results--We retrospectively analyzed 5291 patients who have pauses of < 3 seconds on 24-hour Holter monitoring. Patients with pauses of 2 to 3 seconds constitute the intermediate pause patients, who are further divided into daytime pause (8:00 AM-8:00 PM), nighttime pause (8:00 PM-8:00 AM), and daytime plus nighttime pause groups depending on the occurring time of the pauses. The rest of the patients (pause < 2 seconds) are the no pause group. The multivariate Cox hazards regression model was used to assess the hazard ratio for mortality (primary outcome) and adverse cardiovascular events (secondary outcome). There were 4859 (91.8%) patients in no pause, 248 (4.7%) in nighttime pause, 103 (1.9%) in daytime pause, and 81 (1.5%) in daytime plus nighttime pause groups. After a follow-up of 8.8±1.7 years' follow-up, 343 (6.5%) patients died. The risk for adverse cardiovascular events, including all-cause hospitalization, cardiovascular-cause hospitalization, pacemaker implantation, new-onset atrial fibrillation/heart failure, and transient ischemic attack, were higher in daytime pause and nighttime pause patients than those in the no pause group. Daytime pause (hazard ratio, 2.35; P=0.008) and daytime plus nighttime pause (hazard ratio, 2.26; P=0.016) patients have a higher mortality rate than that in nighttime pause. Conclusions--Patients with intermediate pause are associated with increased cardiovascular risk. Intermediate pauses occurring at daytime have a higher mortality rate than that at nighttime during long-term follow-up.