Relationship between systemic inflammation indices and time of onset of symptoms in cardiac remodeling after first ST-segment elevation myocardial infarction.

BACKGROUND: Circadian variations play a pivotal role in both leukocyte trafficking and inflammatory response. This may affect the fate of cardiac healing after myocardial infarction (MI).

AIMS: The present study investigates the relationship between the systemic immune inflammation (SII) and response (SIRI) indices, two new inflammation indices integrating white blood cells subsets and platelets, and time of onset of symptoms in left ventricular adverse remodeling (LVAR) after ST-elevation MI (STEMI).

METHODS: In this retrospective study, 512 patients with first-time STEMI were included. The time of onset of symptoms was divided into 4 groups of 06:00-11:59, 12:00-17:59, 18:00-23:59, and 00:00-05:59. The endpoint was LVAR, defined as the increase of left ventricular end-diastolic and end-systolic volume by ≥12% at 6 months.

RESULTS: The time of onset of chest pain most often occurred between 06:00 and 11:59 AM. In this window of time, median SII and SIRI indices were higher than other time intervals. Increased SIRI level (OR = 3.03, P < 0.001), symptom onset in morning hours (OR = 2.92, P = 0.03), and increased GRACE score (OR = 1.16, P < 0.001) were determined as independent predictors of LVAR. The threshold value of the SIRI to discriminate between patients with and without LVAR was >2.5 (AUC=0.84, P < 0.001). The SIRI showed superior diagnostic performance compared to the SII.

CONCLUSIONS: In patients with STEMI, increased SIRI was independently associated with LVAR. This was more pronounced at 06:00-11:59 AM. Despite differences across circadian periods, the SIRI may be a potential screening tool for predicting LVAR patients at long-term risk of heart failure.