Heart Rate Fragmentation, Ambulatory Blood Pressure, and Coronary Artery Calcification: A Population-Based Study.

Background: Little is known regarding whether ultra-rapid patterns of heart rate variability (eg, heart rate fragmentation [HRF]) are associated with coronary artery calcification (CAC) in a general population.
Objectives: This study aimed to assess the association between HRF and CAC, and whether these associations are independent of systolic blood pressure (SBP) levels.
Methods: From SESSA (the Shiga Epidemiological Study of Subclinical Atherosclerosis), we used data from 24-hour ambulatory blood pressure monitoring to identify awake and asleep SBP levels, and data from concurrent 24-hour Holter monitoring to quantify HRF using the awake and asleep percentage of inflection points (PIP). CAC on computed tomography scanning was quantified using an Agatston score. We used multivariable binomial logistic regression to assess the associations of PIP and ambulatory SBP with the presence of CAC, as defined by Agatston score >0.
Results: Of the 508 participants in this study (mean age: 66.5 ± 7.3 years), 325 (64%) had CAC and 183 (36%) did not. In fully adjusted models of prevalent CAC that also included office SBP, the ORs with 95% CIs for awake PIP, awake SBP, asleep PIP, and asleep SBP were 1.23 (95% CI: 0.99-1.54), 1.40 (95% CI: 1.11-1.77), 1.31 (95% CI: 1.05-1.62), and 1.28 (95% CI: 1.02-1.60), respectively. There was no evidence of interaction between PIP and ambulatory SBP in association with CAC. Results were similar when other HRF indices instead of PIP were used.
Conclusions: Higher HRF and SBP levels during sleep are each associated with the presence of CAC in a general male population.
Competing Interests: This work was supported by a grant from the Kao Research Council for the Study of Healthcare Science (Tokyo, Japan); by the Uehara Memorial Foundation (Tokyo, Japan); by grant numbers A13307016, A17209023, A21249043, A23249036, A25253046, A15H02528, A18H04074, 17K15827, and 25893097 from the Ministry of Education, Culture, Sports, Science and Technology Japan; and by a grant (HL068200) from the National Institutes of Health. All authors have reported that they have no relationships relevant to the contents of this paper to disclose.
(© 2024 The Authors.)