Improving cardiovascular risk stratification: the role of abdominal obesity in predicting MACEs.

Background: Accurate cardiovascular risk (CVR) stratification remains challenging, particularly in identifying individuals with residual risk despite current screening tools. Abdominal obesity reflects visceral adipose tissue, which is metabolically active and strongly linked to pro-inflammatory and atherogenic states. This study aimed to evaluate the predictive utility of baseline cardiometabolic risk factors, with a particular focus on abdominal obesity as quantified by waist circumference (WC), alongside established 10-year CVR scores, for incident Major Adverse Cardiovascular Events (MACEs).

Methods: We prospectively followed 736 outpatients (347 males, 389 females) from an Italian Internal Medicine Unit, initially free of MACEs. Baseline data included anthropometrics, biochemical markers, and calculated Framingham Risk Score (FRS) and SCORE2/SCORE2-OP. Abdominal obesity was defined according to the International Diabetes Federation criteria for Metabolic Syndrome (MetS) as a WC ≥ 94 cm in males and ≥ 80 cm in females. Incident MACEs were recorded during follow-up. Statistical analyses included t-tests, Chi-Square, ANOVA, and logistic regression.

Results: Over a median follow-up of 84.9 months, 132 participants (17.9%) developed MACEs. Baseline abdominal obesity, present in 78.1% of the cohort, was significantly associated with incident MACEs (OR = 1.784, 95% CI = 1.04-3.118, p = 0.038), whereas BMI-defined obesity showed no such association (p = 0.394). Low HDL-cholesterol also emerged as a key predictor (OR = 1.672, 95% CI = 1.115-2.482, p = 0.012). In multivariate logistic regression, adjusted for age and other MetS components, abdominal obesity (OR = 2.2, 95% CI = 1.6-4.2, p = 0.001) and low HDL-c (OR = 1.9, 95% CI = 1.4-3.5, p = 0.001) remained robustly associated with MACEs. Notably, individuals within the SCORE2/SCORE2-OP 'Moderate-Risk' category, despite not being the highest risk overall, exhibited the highest baseline LDL-c levels and accounted for the largest proportion of MACEs (36.4%). Even among participants without baseline abdominal obesity, those who developed MACEs had significantly higher WC (p < 0.0001) and lower HDL-c (p = 0.0078) at baseline.

Conclusion: Abdominal obesity and low HDL-c are potent, independent predictors of cardiovascular events, outperforming traditional markers like BMI. Together with the need of reaching LDL-c serum target levels, these biomarkers are crucial for unmasking the residual risk missed by current stratification models.