Metabolic syndrome and its components reduce coronary collateralization in chronic total occlusion: An observational study

BACKGROUND: Metabolic syndrome (MetS) is an independent risk factor for the incidence of cardiovascular diseases. We investigated whether or to what extent MetS and its components was associated with coronary collateralization (CC) in chronic total occlusion (CTO). METHODS: This study involved 1653 inpatients with CTO. Data on demographic and clinical characteristics were collected by cardiovascular doctors. The CC condition was defined by the Rentrop scoring system. Subgroup analysis, mixed model regression analysis, scoring systems and receiver operating characteristic (ROC) curve analysis were performed. RESULTS: Overall, 1653 inpatients were assigned to the poor CC group (n = 355) and good CC group (n = 1298) with or without MetS. Compared to the good CCs, the incidence of MetS was higher among the poor CCs for all patients. Poor collateralization was present in 7.6%, 14.2%, 19.3%, 18.2%, 35.6% and 51.1% of the six groups who met the diagnostic criteria of MetS 0, 1, 2, 3, 4 and 5 times, respectively. For multivariable logistic regression, quartiles of BMI remained the risk factors for CC growth in all subgroups (adjusted OR = 1.755, 95% CI 1.510–2.038, P < 0.001 all patients; adjusted OR = 1.897, 95% CI 1.458–2.467, P < 0.001 non-MetS; and adjusted OR = 1.814, 95% CI 1.482–2.220, P < 0.001 MetS). After adjustment for potential confounding factors, MetS was an independent risk factor for CC growth in several models. Assigning a score of one for each component, the AUCs were 0.629 (95% CI 0.595–0.662) in all patients, 0.656 (95% CI 0.614–0.699) in MetS patients and 0.569 (95% CI 0.517–0.621) in non-MetS patients by receiver operating characteristic analysis. CONCLUSIONS: MetS, especially body mass index, confers a greater risk of CC formation in CTO. The value of scoring systems should be explored further for CTO.