Association between the Atherosclerotic Modifiable Risk Factor Burden and Coronary Inflammation

The relationship between multiple modifiable risk factors (RFs) and coronary plaque development remains unclear. This study investigated the relationship between the cumulative RF burden and coronary inflammation, a key driver of atherosclerosis, and whether this relationship varies according to the status of coronary artery stenosis.

We analyzed 958 patients who underwent coronary computed tomography angiography. Modifiable RFs included hypertension, diabetes, a body mass index ≥ 30 kg/m ², and current smoking status. Risk factor burden was categorized by the number of risk factors, ranging from none to ≥ 2. Coronary inflammation was quantified by the perivascular fat attenuation index (FAI), defining a high FAI as a value above the 75th percentile (＞-70.2 HU).

Among the patients, 142 had no RFs, 467 had 1 RF, and 349 had ≥ 2 RFs. The median FAI was -76.2HU, and a high FAI was observed in 239 patients. Compared to those with no RFs, the multivariable Poisson regression with robust error variance demonstrated a significant increase in the prevalence of a high FAI among patients with higher RF burdens: 1 RF (relative risk [RR] 1.56; 95% confidence interval [CI], 1.06-2.30) and ≥ 2 RFs (RR 1.71; 95% CI, 1.16-2.52). Similar associations were observed in patients with no or minimal atheroma (＜25%): one RF (RR, 1.65; 95% CI, 1.01-2.68) and ≥ 2 RFs (RR 2.25; 95% CI, 1.38-3.66).

A greater RF burden was associated with increased coronary inflammation in a dose-dependent manner. These findings indicate that RF clustering is associated with higher coronary inflammation even in the absence of significant coronary plaque.