Association Between Surrogate Index of Insulin Resistance and Coronary Collateral Circulation in Patients with Coronary Chronic Total Occlusion Lesions

Background: Recent studies have substantiated the role of triglyceride glucose index (TyG index) in the prognosis of coronary artery disease (CAD) patients while no relevant studies revealed the association between TyG index and coronary collateral circulation (CCC) in the event of coronary chronic total occlusion (CTO). Our study intends to explore whether or to what extent TyG index is associated with less developed CCC in CAD patients with CTO lesions.Methods: The study enrolled 1093 ACS patients undergoing percutaneous coronary intervention (PCI) for at least one CTO lesion. Relevant data was collected from Beijing Anzhen Hospital record system. The degree of collaterals was determined according to Rentrop classification system. The correlation between TyG index and coronary collateralization was assessed.Results: Overall, 318 patients were divided into poor CCC group. TyG index was significantly higher in patients with poor CCC (9.3±0.65 vs. 8.8±0.53, P＜0.001). After adjusting for various confounding factors, TyG index remained to be correlated with the occurrence of poor CCC, with an ORs (95% CIs) of 1.59 (1.07-2.36) in T2 group and 5.72 (3.83-8.54) in T3 group compared with the first tertile. Besides, subgroup analysis showed that higher TyG index values remained to be strongly associated with increased risks of poor CCC. Lastly, to compare the risk assessment efficacy for the formation of CCC between TyG index and glycosylated hemoglobin A1c (HbA1c) and another insulin resistance (IR) surrogate marker triglyceride-to-high-density lipoprotein cholesterol ratio, area under the receiver-operating characteristic (ROC) curve (AUC) was obtained, a significant improvement on the risk assessment performance for the poor CCC emerged when adding TyG index into a baseline model [AUC, 0.629 for baseline model vs. 0.724 for baseline model + TyG index vs. 0.638 for baseline model +HbA1c vs. 0.721 for baseline model +TG/HDL-C, P<0.001; net reclassification improvement (NRI) for TyG index, 0.238, P＜0.001; integrated discrimination improvement (IDI) for TyG index, 0.103, P＜0.001].Conclusions: The TyG index is strongly associated with the occurrence of poor CCC in CAD patients with CTO lesions and its risk assessment performance is better than HbA1c and TG-to-HDL-C ratio.

Extracardiac coronary steal induced by upper limb hyperemia: a feature of internal mammary artery arteriogenesis

Introduction Function of naturally existing internal mammary artery (IMA)-to-coronary artery anastomoses has been shown by augmented blood supply to the coronary collateral circulation in response to IMA occlusion. Theoretically, this beneficial functional connection is invertible and can be linked to coronary steal, the verification of whose hypothesis would provide alternate proof to the mentioned functional evidence. Method This was an observational study including 40 patients with chronic coronary syndrome,distal IMA occlusion and upper limb hyperemia (verum group), and 40 propensity score matched controls (placebo group) without IMA occlusion or hyperemia. Primary study endpoint was the inter-group difference and temporal development in coronary collateral function (i.e., collateral flow index, CFI) as obtained at 30, 45 and 60 seconds following a proximal coronary artery balloon occlusion. CFI is the ratio between simultaneous mean coronary occlusive pressure divided by mean aortic pressure both subtracted by central venous pressure. To provoke a steal phenomenon, upper limb hyperemia was induced by upper arm blood pressure cuff deflation following a 5-minute supra-systolic inflation ipsilateral to the sensor-wired coronary artery with release immediately after the first CFI measurement. Results Between the first and the second CFI measurement, CFI change (i.e., CFI@45s minus CFI@30s) was absent in the verum group while there was CFI recruitment in the placebo group: 0.000±0.023 and +0.009±0.013, respectively; p=0.032. Conclusion Among patients with artificial distal IMA occlusion, induction of ipsilateral upper limb hyperemia provokes extracardiac coronary steal as expressed by temporarily absent collateral recruitment as it normally takes place without upper limb hyperemia.

Systemic immune inflammation index: a novel predictor for coronary collateral circulation

Aim: Recently, a new inflammatory and prognostic marker has emerged called as Systemic Immune Inflammation Index (SII). In the current study, we searched the relation between SII and Coronary Collateral Circulation (CCC) formation in stable Coronary Artery Disease (CAD). Materials & methods: 449 patients with stable CAD who underwent coronary angiography and documented coronary stenosis of 95% or more in at least one major coronary vessel were included in the study. The study patients were divided into two groups according to the Rentrop score as well CCC (Rentrop 2–3) and bad CCC (Rentrop 0–1). Blood samples for SII and other laboratory parameters were gathered from all the patients on admission. The SII score was formulized as platelet × neutrophil/lymphocyte counts. Results: Patients, who had developed bad CCC had a higher C-reactive protein (CRP), neutrophil/lymphocyte ratio (NLR), platelets/lymphocyte ratio (PLR) and SII levels compared to those who had developed well CCC (p < 0.001, for all). Multivariate logistic regression analysis showed that high levels of SII was an independent predictor of bad CCC (OR: 1.005, 95% confidence interval (CI): 1.003–1.006, p < 0.001) together with dyslipidemia, high levels of CRP and NLR. In Receiver Operator Characteristic curve (ROC) analysis, the optimal cutoff value of SII to predict poor CCC was found to be 729.8, with 78.4% sensitivity and 74.6% specificity (area under ROC curve = 0.833 (95% CI: 0.777–0.889, p < 0.001). Conclusion: We have demonstrated that SII, a novel cardiovascular risk marker, might be used as one of the independent predictors of CCC development.

Coronary Collateral Flow Index Is Correlated With the Palmar Collateral Flow Index

Objective: The extent of the collateral circulation varies between individuals which affects morbidity and mortality. Experimental data show that collateral coherence between different organs is strain-dependent. Whether this interrelation is also present in humans is unknown. This study investigates the relation between the palmar and the coronary circulation in patients with coronary artery disease and which factors possibly influence collateral development. Approach and Results: In 50 patients with a chronic total occlusion, both the coronary collateral flow index (CFI) and the palmar CFI was measured. The correlation between both indices was determined, together with the relation to clinical variables. Mean coronary CFI was 0.51±0.16, and mean palmar CFI was 0.82±0.13. The coronary and palmar CFI were significantly correlated (ρ=0.48, P =0.001). Coronary CFI was 22% lower in low palmar CFI patients (<0.82) as compared with high palmar CFI patients (0.43±0.12 versus 0.57±0.18, P =0.03). In multivariable analysis, coronary CFI was significantly correlated with the palmar CFI and the duration of angina pectoris. Coronary CFI was inversely correlated with peripheral artery disease and systolic blood pressure. Conclusions: The coronary CFI and palmar CFI are significantly correlated, implicating collateral coherence between vascular beds in humans.