Triglyceride glucose-body mass index as a novel predictor of slow coronary flow phenomenon in patients with ischemia and nonobstructive coronary arteries (INOCA).

BACKGROUND: The triglyceride glucose-body mass index (TyG-BMI index) has been suggested as a novel predictor of insulin resistance. However, its predictive value for slow coronary flow phenomenon (SCFP) in patients with ischemia and nonobstructive coronary arteries (INOCA) remains unclear. METHODS: We consecutively recruited 1625 patients with INOCA from February 2019 to February 2023 and divided them into two groups based on thrombolysis in myocardial infarction (TIMI) frame counts (TFCs): the SCFP group (n = 79) and the control group. A 1:2 age-matched case-control study was then performed. The TyG-BMI index was calculated as ln [plasma triglyceride (mg/dL) × fasting blood glucose (mg/dL)/2] × BMI. RESULTS: TyG-BMI index in the SCFP group (218.3 ± 25.2 vs 201.0 ± 26.5, P < .001) was significantly higher than in the normal controls. TyG-BMI index also increased with the number of coronary arteries involved in the SCFP. Multivariate logistic regression analysis showed that TyG-BMI, BMI, and TG were independent predictors for SCFP. Receiver operating characteristic (ROC) curve analysis showed that when the TyG-BMI index was above 206.7, the sensitivity and specificity were 88.6% and 68.5%, respectively, with an AUC of 0.809 (95% CI: 0.756-0.863, P = .027). Combined BMI with TG, the TyG-BMI index had a better predictive value for SCFP than BMI and TG (P < .001). CONCLUSION: The TyG-BMI index was an independent predictor for SCFP in INOCA patients, and it had a better predictive value than BMI and TG.

Vascular response profiles following a nano polymer-free sirolimus-eluting stent implantation assessed by optical coherence tomography in a porcine model.

Optical coherence tomography (OCT) is a high resolution imaging modality and has been considered as the ideal tool for the evaluation of neointimal tissue and vascular responses following stent implantation. However, vascular response profiles following the implantation of a novel nano polymer-free sirolimus-eluting stent (SES) assessed by OCT has not been fully investigated. Therefore, the aim of the present study was to determine the effects of a nano polymer-free SES on neointimal formation using OCT. A total of 16 nano polymer-free SESs were implanted in the coronary arteries of 8 pigs. At 3 (n=4) or 6 months (n=4), the animals were euthanized following OCT evaluation and the stented arterial segments were analyzed by histological analysis. Neointimal area, thickness and burden were evaluated by OCT. In addition, strut-associated inflammation, stent endothelialization and arterial injury were investigated by histomorphological analysis. OCT examination showed that at 6 months, neointimal thickness (193.3±109.5 vs. 167.2±119.7 µm, P=0.023) and neointimal burden (29.3±14.3 vs. 24.8±17.4%, P=0.006) significantly increased compared with at 3 months. Histomorphological analysis indicated that the endothelialization score was significantly greater at 6 months compared with at 3 months (2.85±0.36 vs. 2.52±0.60, P<0.001). However, at 3 months, nano polymer-free SES showed a significantly higher inflammatory score [0 (0, 1) vs. 0 (0, 0), P<0.001] compared with at 6 months. In conclusion, nano polymer-free SES achieves endothelialization at 3 months; however, neointimal proliferation is more significant at 6 months and may be attributed to strut-associated inflammation.

Histological validation of frequency domain optical coherence tomography for the evaluation of neointimal formation after a novel polymer-free sirolimus-eluting stent implantation.

Novel polymer-free drug-eluting stents have been developed to reduce polymer-related adverse events. However, neointimal coverage after polymer-free DES implantation is unclear and validation between optical coherence tomography (OCT) and histology is required. Sixteen polymer-free sirolimus-eluting stents were randomly implanted into coronary arteries of 8 normal swine. OCT and histological measurement were conducted at 3 or 6 months after stent placement. For quantitative measures, lumen area, stent area, neointimal area and neointimal thickness were validated in every single OCT and histology matched cross-section. Moreover, for qualitative analysis, OCT signal patterns of neointimal tissue were classified as homogeneous, layered and heterogeneous patterns based on optical intensity and backscatter pattern and peri-strut inflammation was also determined by histology. In total, 70 OCT and histology matched cross-sections were analyzed. At quantitative analysis, good correlations and agreements were found in the measurement of lumen area (ICC = 0.67, P<0.001), neointimal area (ICC = 0.89, P<0.001) and neointimal thickness (ICC = 0.94, P<0.001) except for stent area (ICC 0.19, P = 0.13) between OCT and histology. At qualitative analysis, lymphocyte infiltrations of peri-strut were more frequently seen in heterogeneous sections than in homogeneous sections (10/14 sections, 71.4% vs. 12/50 sections, 24%; P = 0.003). In conclusion, OCT has proper correlation and agreement with histology in assessment of neointimal formation and heterogeneous neointima assessed by OCT may also be associated with peri-strut inflammation detected in histology after polymer-free sirolimus-eluting stents implantation, supporting the use of OCT to evaluate neointimal coverage after polymer-free stent implantation in clinical practice.

Randomized comparative study of left versus right radial approach in the setting of primary percutaneous coronary intervention for ST-elevation myocardial infarction.

BACKGROUND: Growing evidence suggests that the left radial approach (LRA) is related to decreased coronary procedure duration and fewer cerebrovascular complications as compared to the right radial approach (RRA) in elective percutaneous coronary intervention (PCI). However, the feasibility of LRA in primary PCI has yet to be studied further. Therefore, the aim of this study was to investigate the efficacy of LRA compared with RRA for primary PCI in ST-elevation myocardial infarction (STEMI) patients. MATERIALS AND METHODS: A total of 200 consecutive patients with STEMI who received primary PCI were randomized to LRA (number [n]=100) or RRA (n=100). The study endpoint was needle-to-balloon time, defined as the time from local anesthesia infiltration to the first balloon inflation. Radiation dose by measuring cumulative air kerma (CAK) and CAK dose area product, as well as fluoroscopy time and contrast volume were also investigated. RESULTS: There were no significant differences in the baseline characteristics between the two groups. The coronary procedural success rate was similar between both radial approaches (98% for left versus 94% for right; P=0.28). Compared with RRA, LRA had significantly shorter needle-to-balloon time (16.0±4.8 minutes versus 18.0±6.5 minutes, respectively; P=0.02). Additionally, fluoroscopy time (7.4±3.4 minutes versus 8.8±3.5 minutes, respectively; P=0.01) and CAK dose area product (51.9±30.4 Gy cm(2) versus 65.3±49.1 Gy cm(2), respectively; P=0.04) were significantly lower with LRA than with RRA. CONCLUSION: Primary PCI can be performed via LRA with earlier blood flow restoration in the infarct-related artery and lower radiation exposure when compared with RRA; therefore, the LRA may become a feasible and attractive alternative to perform primary PCI for STEMI patients.