Circadian patterns of symptom onset in spontaneous coronary artery dissection
J Al-Gully, J M Montero-Cabezas, H C J Eikenboom, P L den Exter, S N M ter Haar, C S R Campbell, M C den Haan, J W Jukema, B O Bingen, I Al AmriAbstract
Background
Acute coronary syndromes (ACS) caused by atherosclerotic plaque rupture show a well-established morning peak in incidence, attributed to circadian fluctuations in sympathetic activity, blood pressure, and platelet reactivity.1 Whether spontaneous coronary artery dissection (SCAD) exhibits a comparable circadian pattern remains unclear.
Objectives
To characterize the circadian distribution of symptom onset in SCAD and to explore differences in clinical, trigger-related, and angiographic characteristics across time-of-day intervals.
Methods
We retrospectively analyzed 195 consecutive SCAD patients included in our institutional registry. Time of symptom onset, or first medical contact when onset was unavailable, was categorized into four 6-hour intervals: night (00:00–05:59), morning (06:00–11:59), afternoon (12:00–17:59), and evening (18:00–23:59). Trigger type was classified as emotional, physical, intense Valsalva, pregnancy, labor and delivery, hormone modulators, or none/unclear. Baseline characteristics, trigger distribution, and angiographic presentation were compared across time bins using chi-square or Fisher’s exact tests, as appropriate.
Results
Among 195 patients with SCAD, the circadian distribution demonstrated a bimodal pattern. Events occurred during the night in 12% (n=23) patients, in the morning in 35% (n=69), in the afternoon in 28% (n=54), and in the evening in 25% (n=49). Rather than a single morning predominance, SCAD showed two peaks, occurring in the late morning/early afternoon and in the evening. Smoking status differed significantly across time intervals, with a higher proportion of current smokers among patients presenting in the afternoon (30%) compared with the night (4%), morning (9%), and evening (14%) (p = 0.020). Trigger type did not vary significantly between time bins. Fibromuscular dysplasia was more frequently observed in patients presenting in the evening (31%) compared with the night (13%), morning (27%), and afternoon (11%) (p = 0.032). SCAD type 1 was more prevalent in patients presenting during the night (17%) and evening (12%) compared with the morning (3%) and afternoon (4%) (p = 0.039).
Conclusions
In contrast to the established morning predominance of atherosclerotic ACS1, SCAD in this cohort showed a distinct bimodal circadian distribution. These findings support the concept that SCAD follows distinct temporal and potentially pathophysiological patterns, which may have implications for disease characterization and future research into tailored management strategies.SCAD onset during a 24-hour period