Changes in collateral channel filling immediately after controlled coronary artery occlusion by an angioplasty balloon in human subjects

Clinical risk score to predict poor coronary collateralization in type 2 diabetic patients with chronic total occlusion

BACKGROUND

This study sought to develop and externally validate a score that predicts the probability for poor coronary collateralization (CC) in stable angina patients with type 2 diabetes mellitus (T2DM).

METHODS

Clinical and laboratory variables were collected on admission in 1022 T2DM patients with chronic total occlusion (CTO). Coronary collaterals with Rentrop score 0 or 1 were considered as poor CC. Multivariable logistic regression analysis was used to identify independent predictors for poor CC. The external validation cohort comprised 234 T2DM patients with CTO selected randomly from an independent external center.

RESULTS

Eight predictors were independently associated with poor CC and applied to construct the risk model. A score incorporating these factors predicted poor CC, ranging from 7% when all factors were absent to 97% when ≥ 7 factors were present. Internal validation showed an AUC of 0.748 (95%CI, 0.695-0.795) and the external validation had an AUC of 0.754 (95%CI, 0.694-0.808). A cumulative predictive score was developed by summing points assigned to each factor based on its regression coefficient. Smoking and neutrophil > 6.5 × 10⁹/L were assigned 3 points, female gender, hypercholesterolemia, and eGFR < 60 mL/min/1.73 m² were assigned 2 points, age > 65 years, hypertension, and HbA1c > 6.5% were assigned 1 point. The optimal cutoff score was 4 for predicting poor CC with sensitivity 75.4% and specificity 64.1%.

CONCLUSIONS

We have demonstrated a risk score based on clinical and laboratory characteristics providing an easy-to-use tool to predict poor CC in T2DM patients with stable coronary artery disease.

CLINICAL TRIAL NUMBER

NCT06054126 Date of registration: September 19th, 2023.

Relationship between choroidal structure and myocardial collateral flow regulation in acute and chronic coronary heart disease

PURPOSE

This study aimed to evaluate the relationship between coronary collateral filling, collateral size, and choroidal parameters in patients with acute and chronic coronary heart disease (CHD).

METHODS

Thirty-eight patients with acute CHD and 38 with chronic CHD who underwent diagnostic angiography in a cardiology clinic were included in this observational cross-sectional study. The control group comprised 32 healthy participants, and we examined both eyes of all participants. Diagnostic coronary angiograms were used to score the coronary collaterals, and choroidal parameters were measured in patients with CHD.

RESULTS

Choroidal vascular index (CVI) and subfoveal choroidal thickness (SFCT) were significantly lower in the chronic CHD group than in the acute CHD and control groups (p < 0.05). In the multinominal logistic regression analysis, collateral size had a significant association with both CVI (OR, 0.751; 95% CI, 0.596-0.947), and SFCT (OR, 0.986; 95% CI, 0.976-0.996) in patients with chronic CHD (p < 0.05). However, in the acute CHD group, no significant relationship was observed among choroidal parameters, collateral size, and filling.

CONCLUSION

Patients with chronic CHD had the lowest mean CVI and SFCT among the three groups, and this may be helpful in indicating chronic myocardial ischaemia. Moreover, an association was observed between larger collateral size and reduced CVI and SFCT in patients with chronic CHD, which may potentially be triggered by decreased angiogenic factors.

Association of wide pulse pressure with coronary collateral flow in patients with ST-elevation myocardial infarction undergoing percutaneous coronary intervention

Coronary collateral flow (CCF) is crucial for myocardial viability in patients with obstructive coronary artery disease, specifically ST-elevation myocardial infarction (STEMI). However, hypertension can contribute to vascular dysfunction and hinder the formation of CCF. Wide pulse pressure (WPP), defined as ≥65 mmHg, may better reflect impaired cardiovascular health compared to classic blood pressure indices. The effect of WPP on CCF remains unclear. Therefore, we aimed to evaluate the impact of WPP on CCF. This retrospective study included 1180 STEMI patients that underwent primary percutaneous coronary intervention (PCI) between 2021 and 2023 at a tertiary healthcare center. Patients were classified into good and poor CCF groups based on the Rentrop classification. Out of these patients, 272 (23.1%) had good CCF, while 908 (76.9%) had poor CCF. Two distinct models were constructed using multivariable logistic regression analysis to identify independent predictors of good CCF, including pulse pressure (Model 1) and WPP (Model 2). Covariates such as age, gender, diabetes mellitus, smoking, pre-infarction angina, Killip Class 3/4, multivessel disease, peak troponin, pre-thrombolysis in myocardial infarction (TIMI) flow 0, and previous PCI were added to both models. WPP was identified as an independent predictor that negatively influences good CCF (OR: 0.511, 95% CI: 0.334-0.783, p = 0.002). Moreover, diabetes, pre-infarction angina, Killip class III/IV, multivessel disease, and pre-TIMI flow 0 were also found to be independent predictors of CCF. WPP, derived from blood pressure measurements, has been associated with poor CCF in STEMI patients undergoing primary PCI and may serve as a predictor of poor CCF.

Elevated systemic immune-inflammatory index predicts poor coronary collateralization in type 2 diabetic patients with chronic total occlusion

Objective

This study compared the value of different systemic immune-inflammatory markers for evaluating coronary collateralization (CC) in patients with type 2 diabetes mellitus (T2DM) and chronic total occlusion (CTO).

Methods

Systemic immune-inflammation index (SII), systemic inflammation response index (SIRI) and pan-immune-inflammation value (PIV) were calculated at admission in 1409 T2DM patients with CTO. The degree of coronary collaterals was estimated using the Rentrop scoring system and categorized into poor (Rentrop score 0 or 1) or good (Rentrop score 2 or 3) CC. The predictors of poor CC were determined by multivariate regression analysis, and the diagnostic potential of these indexes was analyzed by Receiver Operating Characteristic (ROC) curves.

Results

SII, SIRI and PIV levels increased stepwise across Rentrop score 0-3, with significantly higher levels in patients with poor CC than in those with good CC (P < 0.001). After adjusting for confounders, SII, SIRI and PIV (per tertile) remained independent factors for poor CC. SII predicted poor CC better than SIRI and PIV (AUC: 0.758 vs. 0.680 and 0.698, all P < 0.001). There existed an interaction between blood concentration of HbA1c and SII (P < 0.001), with high SII levels being associated with a greater risk (OR: 5.058 vs. 2.444) and providing a better predictive ability for poor CC (AUC: 0.817 vs. 0.731) in patients with HbA1c < 6.5% compared to those with HbA1c ≥ 6.5%.

Conclusion

Our study shows that elevated SII provides a better prediction for poor CC in T2DM patients with CTO especially at good glycemic control.

Bypass of Coronary Artery in Renal Artery Stenosis Patients with Heart Chronic Total Occlusion Might Explain the 5-Year Follow-Up after Percutaneous Coronary Intervention: B-RASHEF Study

INTRODUCTION

Renal artery stenosis (RAS) is associated with poor outcome in patients with ischemic heart disease. In this study, we investigated the development of coronary collateral in RAS patients and possible association of RAS with a 5-year outcome after chronic total occlusion-percutaneous coronary intervention (CTO PCI).

METHODS

Consecutive 58 patients with CTO PCI were enrolled prospectively, including 21 RAS patients (15 unilateral RAS and 6 bilateral RAS) and 37 non-RAS patients. RAS was diagnosed by renal duplex. Coronary collaterals were appraised by CC classification and Rentrop classification.

RESULTS

Development of left anterior descending artery coronary collateral by Rentrop classification was significantly worse in RAS patients than non-RAS patients. Kaplan-Meier curve of survival was significantly worse in RAS patients than non-RAS patients (p = 0.027). By univariate COX proportional hazard regression analysis, collateral development by CC classification was a significant predictor for 5-year survival. When age, RAS, and collateral development by CC classification were included in multivariate COX proportional hazard regression analysis, only age (hazard ratio: 1.349; 95% confidential interval: 1.058-1.720; p = 0.016) and RAS (hazard ratio: 6.680; 95% confidential interval: 1.322-33.747; p = 0.022) were significant predictors for 5-year survival.

DISCUSSION/CONCLUSION

We concluded that survival in RAS patients after CTO PCI is significantly worse than non-RAS patients, and RAS is a significant predictor for survival after CTO PCI. It seems that injured collateral development might partly explain increased all cause death in RAS patients.

Evolving Role of Coronary Collaterals in STEMI Outcomes: A Comparative Analysis of Pandemic and Post-Pandemic Phases

Acute ST-elevation myocardial infarction (STEMI) is a critical condition where coronary collaterals can mitigate myocardial damage. The Coronavirus Disease 2019 (COVID-19) pandemic introduced unique challenges in STEMI management, potentially affecting outcomes. This study evaluates the efficacy of coronary collaterals during the pandemic compared to the post-pandemic period. A review of 1465 STEMI patients treated at a high-volume tertiary care center from April 2020 to December 2022 was conducted. Collaterals were assessed using the Rentrop classification. In-hospital mortality and 1-year major adverse cardiac events (MACE) were analyzed based on collateral status and timeframes. During the pandemic, there was a higher incidence of robust collaterals (28.2% vs 23.2%, P = .04), but they were less protective, with similar in-hospital mortality (14.4% vs 8.1%, P = .07) and 1-year MACE rates (21.9% vs 30.4%, P = .09) across groups. Post-pandemic, robust collaterals showed significant protective effects with reduced in-hospital mortality (3.6% vs 7.4%, P = .04) and 1-year MACE rates (17.1% vs 24.9%, P = .03). These findings highlight a dynamic role of collaterals in STEMI management, with the pandemic impairing their functionality. This underscores the need for adaptive STEMI care strategies, especially during global health crises.

Impact of sex on myocardial perfusion following percutaneous coronary intervention of chronic total coronary occlusions

OBJECTIVES

We sought to investigate the impact of sex on myocardial perfusion changes following chronic total coronary occlusion (CTO) percutaneous coronary intervention (PCI) as measured by [15O]H2O positron-emission tomography (PET) perfusion imaging.

BACKGROUND

CTO PCI has been associated with an increase in myocardial perfusion, yet females are less likely to undergo revascularization. As such, data on the impact of sex on myocardial perfusion following CTO PCI is scarce.

METHODS

A total of 212 patients were prospectively enrolled and underwent CTO PCI combined with [15O]H2O PET perfusion imaging prior to and 3 months after PCI. Hyperemic myocardial blood flow (hMBF, mL·min-1·g-1) and coronary flow reserve (CFR) allocated to the CTO territory were quantitatively assessed.

RESULTS

This study comprised 34 (16 %) females and 178 (84 %) males. HMBF at baseline did not differ between sexes. Females showed a higher increase in hMBF than males (Δ1.34 ± 0.67 vs. Δ1.06 ± 0.74, p = 0.044), whereas post-PCI hMBF was comparable (2.59 ± 0.85 in females vs. 2.28 ± 0.84 in males, p = 0.052). Female sex was independently associated with a higher increase in hMBF after correction for clinical covariates. CFR increase after revascularization was similar in females and males (Δ1.47 ± 0.99 vs. Δ1.30 ± 1.14, p = 0.711).

CONCLUSIONS

The present study demonstrates a greater recovery of stress perfusion in females compared to males as measured by serial [15O]H2O PET imaging. In addition, a comparable increase in CFR was found in females and males. These results emphasize the benefit of performing CTO PCI in both sexes.

CLINICAL PERSPECTIVE

What is new? What are the clinical implications?

Comparison of the effect of uric acid/albumin ratio on coronary colleteral circulation with other inflammation-based markers in stable coronary artery disease patients

BACKGROUND

The Uric acid/Albumin ratio (UAR) has recently been identified as a prominent marker in cardiovascular diseases. In this study, we aimed to reveal the effect of UAR on coronary collateral circulation (CCC) in patients with stable coronary artery disease (CAD) patients by comparing it with conventional inflammation-based markers.

METHODS

In this study, 415 consecutive patients who underwent coronary angiography for stable angina pectoris and were found to have chronic total occlusion in at least one coronary artery were retrospectively included. The study population was divided into two groups as good CCC (Rentrop 2-3) and poor CCC (Rentrop 0-1) according to the Rentrop classification, and the groups were compared in terms of UAR and other traditional inflammation-based markers.

RESULTS

In the poor CCC group, C-reactive protein/albumin ratio (CAR), monocyte/high-density lipoprotein cholesterol ratio (MHR), neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), systemic immune-inflammation index (SII) and UAR were found to be significantly high (p < .05, for all). UAR negatively correlated with rentrop classification (r = -0.383, p < .001). In multivariate regression analysis, MHR, NLR, SII and UAR were determined as independent predictors for poor CCC (p < .05, for all). The ability of UAR to predict poor CCC was superior to uric acid and albumin alone (p < .0001, for both). In addition, UAR was found to be superior to other inflammation-based markers in predicting poor CCC (p < .005, for all).

CONCLUSION

UAR was identified as a strong and independent predictor of CCC. In this context, UAR may be a useful biomarker in the risk prediction of patients with stable CAD.

Effect of Coronary Collateral Supply on Left Ventricular Global Longitudinal Strain after Recanalization of Chronic Total Occlusion

Percutaneous coronary intervention (PCI) to chronic total occlusion (CTO) is still a subject of debate. The primary goal of revascularization is to provide symptomatic relief and enhance left ventricular (LV) functions. Global longitudinal strain (GLS) is proven to be more sensitive than the ejection fraction (EF), especially for subtle ischemic changes. The purpose of this study was to investigate the improvement in LV GLS after revascularization of symptomatic stable coronary patients with single-vessel CTO, categorized according to their collateral supply grades. Sixty-nine patients with successful CTO-PCI were grouped, according to their collateral supply grades, as well-developed (WD) and poor collateral groups and followed-up for 3 months. Basal characteristics were similar for both groups, except for a lower EF (p = 0.04) and impaired GLS (p < 0.0001) in the poor collateral group. At the end of 3 months follow-up, symptomatic relief was similar in both groups (p = 0.101). GLS improvement reached statistical significance only for the poor collateral, not for the WD group (p < 0.0001 and p = 0.054, respectively). The EF did not change significantly in both groups. Poorly collateralized CTO lesions may not only result in baseline LV dysfunction, but also appear to carry potential for recovery after revascularization. This may not be the case for WD collaterals.

Quantitative coronary computed tomography assessment for differentiating between total occlusions and severe stenoses

BACKGROUNDS

The impact of quantitative assessment to differentiate total occlusions (TOs) from severe stenoses on coronary computed tomography angiography (CCTA) remains unknown.

OBJECTIVE

This study investigated whether quantitative characteristics assessed on CCTA could help differentiate a TO from a severe stenosis on invasive coronary angiography (ICA).

METHODS

This study is a sub-analysis of the FASTTRACK CABG (NCT04142021) in which both CCTA and ICA were routinely performed. Quantitative analysis was performed with semi-automated CCTA plaque-analysis software. Blinded analysts compared TOs on CCTA, defined as a complete lack of contrast opacification within the coronary occlusion, with corresponding ICA.

RESULTS

Eighty-four TOs were seen on CCTA in 59 of the 114 patients enrolled in the trial. The concordance in diagnosing a TO between ICA and CCTA was 56.0% (n ​= ​47). Compared to severe stenoses, TOs had a significantly longer lesion length (25.1 ​± ​23.0 ​mm vs 9.4 ​± ​11.2 ​mm, P ​< ​0.001). The best cut-off value to differentiate a TO from severe stenosis was a lesion length of 5.5 ​mm (area under the curve 0.77, 95% CI: 0.66-0.87), with a 91.1% sensitivity and 61.1% specificity. Dense calcium percentage atheroma volume (PAV) was significantly higher in TOs compared to severe stenoses (18.7 ​± ​19.6% vs. 6.6 ​± ​13.0%, P ​< ​0.001), whilst the opposite was seen for fibro-fatty PAV (31.3 ​± ​14.2% vs. 19.5 ​± ​10.5%, P ​< ​0.001). On a multivariable logistic regression analysis, lesion length (>5.5 ​mm) was the only parameter associated with differentiating a TO from a severe stenosis.

CONCLUSION

In quantitative CCTA analysis, a lesion length >5.5 ​mm was the only independent predictor differentiating a TO from a severe stenosis.

NCT REGISTRATION NUMBER

NCT04142021.

Do collaterals to infarct bed in STE-ACS patients undergoing emergent percutaneous coronary revascularization matter? An assessment of a prospective pool for in-hospital course

BACKGROUND

Limited data exist on the role of coronary collaterals circulation (CCC) in patients with ST-elevation acute coronary syndrome (STE-ACS). This study aimed to assess CCC and the in-hospital course of patients with CCC undergoing primary percutaneous coronary intervention (pPCI).

METHODS

The study included consecutive STE-ACS patients undergoing pPCI. Good CCC was defined as Rentrop collateral score (RCS) of 2-3. Patients with good and poor CCC were compared regarding clinical characteristics, angiographic patterns, and hospital course.

RESULTS

In the sample of 4683 patients, mean age was 55.6 ± 11 years, and 78.8 % were male. Good CCC was observed in 499 (10.7 %) patients. The rate of intra-procedure slow-flow/no-reflow (SF/NR) was 29.9 % vs. 20.5 % (p < 0.001), and the rate of composite adverse clinical outcomes (CACO) was 21.2 % vs. 19 % (p = 0.225) for patients with good and poor CCC, respectively. Multivariable analysis identified left ventricular end-diastolic pressure (LVEDP), multi-vessel disease (MVD), and thrombus grade ≥4 as independent predictors of good CCC, with adjusted odds ratios of 0.98 [0.97-0.99], 1.69 [1.35-2.10], and 3.45 [2.64-4.52], respectively. In propensity-matched cohorts, the intra-procedure SF/NR rate was 29.9 % vs. 26.9 % (p = 0.292), and the rate of CACO was 21.2 % vs. 23.4 % (p = 0.403) for patients with good and poor CCC, respectively.

CONCLUSION

Angiographic evidence of good CCC in STE-ACS patients was limited. Good CCC was associated with a higher prevalence of MVD, high thrombus burden, and low pre-procedure LVEDP, resulting in a higher incidence of intra-procedure SF/NR. However, the CACO did not differ significantly between patients with good and poor CCC.

Association between the pan-immune-inflammation value and coronary collateral circulation in chronic total coronary occlusive patients

BACKGROUND

Inflammation and immunity play important roles in the formation of coronary collateral circulation (CCC). The pan-immune-inflammation value (PIV) is a novel marker for evaluating systemic inflammation and immunity. The study aimed to investigate the association between the PIV and CCC formation in patients with chronic total occlusion (CTO).

METHODS

This retrospective study enrolled 1150 patients who were diagnosed with CTO through coronary angiographic (CAG) examinations from January 2013 to December 2021 in China. The Cohen-Rentrop criteria were used to catagorize CCC formation: good CCC formation (Rentrop grade 2-3) and poor CCC formation group (Rentrop grade 0-1). Based on the tertiles of the PIV, all patients were classified into three groups as follows: P1 group, PIV ≤ 237.56; P2 group, 237.56< PIV ≤ 575.18; and P3 group, PIV > 575.18.

RESULTS

A significant relationship between the PIV and the formation of CCC was observed in our study. Utilizing multivariate logistic regression and adjusting for confounding factors, the PIV emerged as an independent risk factor for poor CCC formation. Notably, the restricted cubic splines revealed a dose-response relationship between the PIV and risk of poor CCC formation. In terms of predictive accuracy, the area under the ROC curve (AUC) for PIV in anticipating poor CCC formation was 0.618 (95% CI: 0.584-0.651, P < 0.001). Furthermore, the net reclassification index (NRI) and integrated discrimination index (IDI) for PIV, concerning the prediction of poor CCC formation, were found to be 0.272 (95% CI: 0.142-0.352, P < 0.001) and 0.051 (95% CI: 0.037-0.065, P < 0.001), respectively. It's noteworthy that both the NRI and IDI values were higher for PIV compared to other inflammatory biomarkers, suggesting its superiority in predictive capacity.

CONCLUSIONS

PIV was associated with the formation of CCC. Notably, PIV exhibited potential as a predictor for poor CCC formation and showcased superior predictive performance compared to other complete blood count-based inflammatory biomarkers.

Association between hibernating myocardium and collateral circulation in patients with coronary chronic total occlusion

Objective

To explore the association between the quantity of hibernating myocardium (HM) and collateral circulation in patients with coronary chronic total occlusion (CTO).

Materials and methods

88 CTO patients were retrospectively analyzed who underwent evaluation for HM using both 99mTc-sestamibi Single photon emission computed tomography (99mTc-MIBI SPECT) myocardial perfusion imaging (MPI) combined with 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) myocardial metabolism imaging (MMI). They were divided into two groups according Rentrop grading: the poorly/well-developed collateral circulation group (PD/WD group, Rentrop grades 0-1/2-3). After adjusting for the potential confounding factors and conducting a stratified analysis, we explored the association between the HM index within CTO region and the grading of collateral circulation.

Results

In the WD group, the HM index was notably higher than PD group (46.2 ± 15.7% vs. 20.9 ± 16.7%, P < 0.001). When dividing the HM index into tertiles and after adjusting for potential confounders, we observed that the proportion of patients with WD rose as the HM index increased (OR: 1.322, 95% CI: 0.893-1.750, P < 0.001), the proportion of patients with WD was 17.4%, 63.3%, and 88.6% for Tertile 1 to Tertile 3.This increasing trend was statistically significant (OR: 1.369, 95% CI: 0.873-1.864, P < 0.001), especially between Tertile 3 vs. Tertile 1 (OR: 4.330, 95% CI: 1.459-12.850, P = 0.008). Curve fitting displaying an almost linear positive correlation between the two.

Conclusion

The HM index within CTO region is an independent correlation factor for the grading of coronary collateral circulation. A greater HM index corresponded to an increased likelihood of WD.

Effects of a prior failed attempt on the outcomes of subsequent chronic total occlusion-percutaneous coronary intervention

Objectives

Patients undergoing a prior failed attempt of chronic total occlusion-percutaneous coronary intervention (CTO-PCI) represent a challenging subgroup across all patients undergoing CTO-PCI. There are limited data on the effects of a prior failed attempt on the outcomes of subsequent CTO-PCI. We aimed to compare the procedural results and 24-month outcomes of prior-failed-attempt CTO-PCI with those of initial-attempt CTO-PCI.

Methods

Patients who underwent attempted CTO-PCI between January 2017 and December 2019 were prospectively enrolled. We analyzed the procedural results and 24-month major adverse cardiac events (MACE) between patients who underwent prior-failed-attempt and initial-attempt CTO-PCI. MACE was defined as a composite of cardiac death, target vessel-related myocardial infarction, and ischemia-driven target vessel revascularization (TVR) during follow-up.

Results

In total, 484 patients who underwent CTO-PCI (prior-failed-attempt, n = 49; initial-attempt, n = 435) were enrolled during the study period. After propensity score matching (1:3), 147 patients were included in the initial-attempt group. The proportion of the Japanese-CTO (J-CTO) score ≥2 was higher in the patients who underwent prior failed attempt than in those who underwent initial attempt (77.5% vs. 38.8%, p < 0.001). The retrograde approach was more often adopted in the prior-failed-attempt group than in the initial-attempt group (32.7% vs. 3.4%,  [P< 0.001). Successful CTO revascularization rates were significantly lower in the prior-failed attempt-group than in the initial attempt group (53.1% vs. 83.3%, P < 0.001). The multivariate analysis revealed that J-CTO score ≥2 [odds ratio (OR), 0.359; 95% confidence interval (CI), 0.159-0.812; P = 0.014], intravascular ultrasound procedure (OR, 4.640; 95% CI, 1.380-15.603; P = 0.013), and prior failed attempt (OR, 0.285; 95% CI, 0.125-0.648; P = 0.003) were the independent predictors for successful CTO revascularization. There were no significant differences in major procedural complications (2.0% vs. 0.7%, p = 0.438) and MACE rates (4.1% vs. 8.8%, p = 0.438) between the groups, mainly due to the TVR rate (4.1% vs. 8.2%, P = 0.522).

Conclusions

Compared with initial-attempt CTO-PCI, prior-failed-attempt CTO-PCI deserves more attention, since it is associated with a lower successful CTO revascularization rate. Prior failed attempt, J-CTO score ≥2, and IVUS procedure are the determining factors for predicting successful CTO revascularization. There are no significantly different unfavorable outcomes between patients who undergo prior-failed-attempt and initial-attempt CTO-PCI.

Association between the atherogenic index of plasma and coronary collateral circulation in patients with chronic total occlusion

BACKGROUND

The atherogenic index of plasma (AIP) is considered an independent risk factor for coronary artery disease (CAD). The present study investigated whether AIP correlates with the formation of coronary collateral circulation (CCC) in CAD patients with chronic total occlusion (CTO).

METHODS

This retrospective study included 1093 CAD patients with CTO confirmed by coronary angiography from January 2020 to December 2020 at Beijing Anzhen Hospital. Based on the Rentrop scoring system, the patients were divided into the good CCC group and the poor CCC group. AIP was calculated by log (triglyceride/high-density lipoprotein cholesterol). Meanwhile, the study population was further divided into four groups according to the quartiles of AIP.

RESULTS

Patients in the poor CCC group exhibited significantly higher AIP compared to those in the good CCC group (0.31 ± 0.27 vs. 0.14 ± 0.24, p < 0.001). Multivariate logistic regression analysis revealed an independent association between AIP and poor CCC, regardless of whether AIP was treated as a continuous or categorical variable (p < 0.001), after adjusting for confounding factors. Besides, this association remained consistent across most subgroups. The incorporation of AIP into the baseline model significantly enhanced the accuracy of identifying poor CCC [area under the curve (AUC): baseline model, 0.661 vs. baseline model + AIP, 0.721, p for comparison < 0.001].

CONCLUSIONS

Elevated AIP is independently associated with an increased risk of poor CCC in CAD patients with CTO, and AIP may improve the ability to identify poor CCC in clinical practice.

Circulating Progenitor Cells and Coronary Collaterals in Chronic Total Occlusion

BACKGROUND

The role of circulating progenitor cells (CPC) in collateral formation that occurs in the presence of chronic total occlusions (CTO) of a coronary artery is not well established. In stable patients with a CTO, we investigated whether CPC levels are associated with (a) collateral development and (b) ischemic burden, as measured by circulating high sensitivity troponin-I (hsTn-I) levels.

METHODS

CPCs were enumerated by flow cytometry as CD45med+ blood mononuclear cells expressing CD34 and both CD34 and CD133 epitopes. The association between CPC counts and both Rentrop collateral grade (0, 1, 2, or 3) and hsTn-I levels were evaluated using multivariate regression analysis, after adjusting for demographic and clinical characteristics.

RESULTS

In 89 patients (age 65.5, 72% male, 27% Black), a higher CPC count was positively associated with a higher Rentrop collateral grade; [CD34+ adjusted odds ratio (OR) 1.49 95% confidence interval (CI) (0.95, 2.34) P = 0.082] and [CD34+/CD133+ OR 1.57 95% CI (1.05, 2.36) P = 0.028]. Every doubling of CPC counts was also associated with lower hsTn-I levels [CD34+ β -0.35 95% CI (-0.49, -0.15) P = 0.002] and [CD34+/CD133+ β -0.27 95% CI (-0.43, -0.08) P = 0.009] after adjustment.

CONCLUSION

Individuals with higher CPC counts have greater collateral development and lower ischemic burden in the presence of a CTO.

The Importance of Pan-Immune Inflammation Value (PIV) in Predicting Coronary Collateral Circulation in Stable Coronary Artery Patients

In this study, the correlation between pan-immune-inflammation value (PIV) and coronary collateral circulation (CCC) in patients with chronic coronary syndrome (CCS) was analyzed. The study included 663 patients with CCS who underwent coronary angiography and had coronary stenosis of ≥95% in at least one major coronary vessel. The participants were divided into two groups: good CCC (Rentrop score 2-3) and poor CCC (Rentrop score 0-1). PIV score was calculated as monocyte x platelet x neutrophil/lymphocyte count. When the patient groups who developed good and poor CCC were compared, neutrophil/lymphocyte ratio (NLR) (P < .001), C-reactive protein (CRP) levels, CRP/albumin ratio (CAR) (P < .001), systemic immune-inflammation index (SII) (P < .001), and PIV (P < .001) were higher in patients with poor CCC. In multivariate logistic regression analysis, age, SII, NLR, CRP, CAR, and PIV were found to be independent predictors of poor CCC (P < .001, for all). Receiver operating characteristic (ROC) analysis demonstrated that a cut-off value of 442.2 for PIV predicted poor CCC slightly better compared to other markers, with 76.8% sensitivity and 70.1% specificity (area under ROC curve = 0.808 (95% CI: 0.764-0.851), P < .001). These findings suggest that PIV can be used as an independent predictor of CCC development.

Same-day discharge after large-bore access in percutaneous coronary intervention of chronic total coronary occlusions

BACKGROUND

Same-day discharge (SDD) in patients undergoing percutaneous coronary intervention (PCI) of a chronic total occlusion (CTO) is appealing because of the increased patient comfort. However, data on SDD following large-bore vascular access are scarce.

AIMS

We investigated the feasibility and safety of SDD in patients undergoing large-bore CTO PCI.

METHODS

Between 2013 and 2023, 948 patients were prospectively enrolled in a single-centre CTO registry and underwent CTO PCI. SDD was pursued in all patients. Large-bore access was defined as the use of ≥7 French (Fr) sheaths in ≥1 access site. A logistic regression analysis was used to identify predictors for non-SDD. Clinical follow-up was obtained at 30 days.

RESULTS

SDD was observed in 62% of patients. Large-bore access was applied in 99% of the cohort. SDD patients were younger and more often male, with lower rates of renal insufficiency and prior coronary artery bypass grafting. Local access site bleeding (odds ratio [OR] 8.53, 95% confidence interval [CI]: 5.24-13.87) and vascular access complications (OR 7.23, 95% CI: 1.98-26.32) made hospitalisation more likely, with vascular access complications occurring in 3%. At 30 days, the hospital readmission rate was low in both SDD and non-SDD patients (5% vs 7%; p=non-significant). Finally, SDD was not a predictor for major adverse cardiovascular events (MACE) at follow-up.

CONCLUSIONS

Same-day discharge can be achieved in the majority of patients undergoing CTO PCI with large-bore (≥7 Fr) access. Similar low hospital readmission and MACE rates between SDD and non-SDD patients at 30 days demonstrate the feasibility and safety of SDD.

Impact of a Chronic Total Coronary Occlusion on the Incidence of Appropriate Implantable Cardioverter-Defibrillator Shocks and Mortality: A Substudy of the Dutch Outcome in ICD Therapy (DO-IT)) Registry

BACKGROUND

Chronic total coronary occlusions (CTO) substantially increase the risk for sudden cardiac death. Among patients with chronic ischemic heart disease at risk for sudden cardiac death, an implantable cardioverter defibrillator (ICD) is the favored therapy for primary prevention of sudden cardiac death. This study sought to investigate the impact of CTOs on the risk for appropriate ICD shocks and mortality within a nationwide prospective cohort.

METHODS AND RESULTS

This is a subanalysis of the nationwide Dutch-Outcome in ICD Therapy (DO-IT) registry of primary prevention ICD recipients in The Netherlands between September 2014 and June 2016 (n=1442). We identified patients with chronic ischemic heart disease (n=663) and assessed available coronary angiograms for CTO presence (n=415). Patients with revascularized CTOs were excluded (n=79). The primary end point was the composite of all-cause mortality and appropriate ICD shocks. Clinical follow-up was conducted for at least 2 years. A total of 336 patients were included, with an average age of 67±9 years, and 20.5% was female (n=69). An unrevascularized CTO was identified in 110 patients (32.7%). During a median follow-up period of 27 months (interquartile range, 24-32), the primary end point occurred in 21.1% of patients with CTO (n=23) compared with 11.9% in patients without CTO (n=27; P=0.034). Corrected for baseline characteristics including left ventricular ejection fraction, and the presence of a CTO was an independent predictor for the primary end point (hazard ratio, 1.82 [95% CI, 1.03-3.22]; P=0.038).

CONCLUSIONS

Within this nationwide prospective registry of primary prevention ICD recipients, the presence of an unrevascularized CTO was an independent predictor for the composite outcome of all-cause mortality and appropriate ICD shocks.

Prognostic Nutritional Index is Associated with the Degree of Coronary Collateral Circulation in Stable Angina Patients with Chronic Total Occlusion

BACKGROUND

Coronary collateral circulation (CCC) can effectively improve myocardial blood supply to the area of CTO (chronic total coronary occlusion) and can, thus, improve the prognosis of patients with stable coronary syndrome (SCS). The degree of inflammation and some inflammation markers were associated with the development of collaterals.

OBJECTIVE

To investigate whether prognostic nutritional index (PNI) has an association with the development of CCC in patients with SCS.

METHODS

A total of 400 SCS patients with the presence of CTO in at least one major epicardial coronary artery were included in this study. The patients were divided into two groups according to the Rentrop score. Scores of 0 to 1 were considered poor developed CCC, and scores of 2 to 3 were accepted as good developed CCC. Statistical significance was set as a p-value < 0.05 for all analyses.

RESULTS

The mean age of the study cohort was 63±10 years; 273 (68.3%) were males. The poor-developed CCC group had a significantly lower PNI level compared with the good-developed CCC group (38.29±5.58 vs 41.23±3.85, p< 0.001). In the multivariate analysis, the PNI (odds ratio 0.870; 95% confidence interval 0.822-0.922; p< 0.001) was an independent predictor of poorly developed CCC.

CONCLUSION

The PNI can be used as one of the independent predictors of CCC formation. It was positively associated with the development of coronary collaterals in SCS patients with CTO.

Coronary chronic total occlusion on coronary CT angiography: what radiologists should know?

Coronary chronic total occlusion (CTO) often occurs in patients with obstructive coronary artery disease, which remains one of the greatest challenges for interventional cardiologists. Coronary computed tomography angiography (CCTA) with its emerging post-processing techniques can provide a detailed assessment of CTO lesions before percutaneous coronary intervention (PCI), playing an important role in the clinical management of CTO PCI, from early diagnosis, pre-procedural outcome prediction, the crossing algorithm planning, intraprocedural guidance, and finally post-procedural assessment and follow-up. In addition, the feasibility of CT perfusion (CTP) in patients with CTO has been validated. Combined CCTA and CTP have the great potential to be the one-stop-shop imaging modality for assessing both anatomy and function of CTO lesions. This review aims to make radiologists understand the role of CCTA in the diagnosis and assessment of CTO lesions, thus assisting interventionalists in optimizing CTO PCI crossing strategies with the expertise of radiologists.Critical relevance statement The anatomical features of CTO on CCTA can reveal the complexity of CTO lesions and are associated with CTO PCI outcome, thus helping interventionalists optimize CTO PCI crossing strategies.Key points • CTO is the common lesion in invasive coronary angiography, and CTO PCI is technically difficult and its success rate is relatively low.• Length, collaterals, and attenuation-related signs can help distinguish CTO from subtotal occlusion.• The anatomical features of CTO lesions can help grade the difficulty of CTO PCI and predict procedural outcomes and long-term outcomes of CTO PCI.• The real-time fusion of CCTA with fluoroscopic angiography can be applied in highly complicated CTO lesions.• After CTO PCI, CCTA can help guide a second CTO PCI re-entry or follow up stent patency.

Presence and Relevance of Myocardial Bridge in LAD-PCI of CTO and Non-CTO Lesions

BACKGROUND

Intravascular ultrasound (IVUS) studies show that one-quarter of left anterior descending (LAD) arteries have a myocardial bridge. An MB may be associated with stent failure when the stent extends into the MB.

OBJECTIVES

The aim of this study was to investigate: 1) the association between an MB and chronic total occlusion (CTO) in any LAD lesions; and 2) the association between an MB and subsequent clinical outcomes after percutaneous coronary intervention in LAD CTOs.

METHODS

A total of 3,342 LAD lesions with IVUS-guided percutaneous coronary intervention (280 CTO and 3,062 non-CTO lesions) were included. The primary outcome was target lesion failure (cardiac death, target vessel myocardial infarction, definite stent thrombosis, and ischemic-driven target lesion revascularization).

RESULTS

An MB by IVUS was significantly more prevalent in LAD CTOs than LAD non-CTOs (40.4% [113/280] vs 25.8% [789/3,062]; P < 0.0001). The discrepancy in CTO length between angiography and IVUS was greater in 113 LAD CTOs with an MB than 167 LAD CTOs without an MB (6.0 [Q1, Q3: 0.1, 12.2] mm vs 0.2 [Q1, Q3: -1.4, 8.4] mm; P < 0.0001). Overall, 48.7% (55/113) of LAD CTOs had a stent that extended into an MB after which target lesion failure was significantly higher compared to a stent that did not extend into an MB (26.3% vs 0%; P = 0.0004) or compared to an LAD CTO without an MB (26.3% vs 9.6%; P = 0.02).

CONCLUSIONS

An MB was more common in LAD CTO than non-CTO LAD lesions. If present, approximately one-half of LAD CTOs had a stent extending into an MB that, in turn, was associated with worse outcomes.

Absence of visible infarction on cardiac magnetic resonance imaging despite the established diagnosis of myocardial infarction by 4th Universal Definition of Myocardial Infarction

AIMS

Myocardial scarring due to acute myocardial infarction (AMI) can be visualized by late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) imaging. However, a recent study revealed a group of Type 1 AMI patients with undetectable myocardial injury on LGE. This study aims to describe these cases in detail and explore possible explanations for this new phenomenon.

METHODS AND RESULTS

A total of 137 patients diagnosed with either ST-elevation myocardial infarction (STEMI) or non-ST-elevation myocardial infarction (non-STEMI) diagnosed according to the 4th Universal Definition of Myocardial Infarction underwent LGE-CMR after invasive coronary angiography. Fourteen of them (10.2%) showed no LGE and were included in the final study population. Most patients presented with acute chest pain, 3 patients were diagnosed as STEMI, and 11 as non-STEMI. Peak high-sensitive cardiac troponin T ranged from 45 to 1173 ng/L. A culprit lesion was identified in 12 patients. Severe coronary stenoses were found in five patients, while seven patients had subtotal to total coronary artery occlusion. Percutaneous coronary intervention was performed in 10 patients, while 2 patients required coronary artery bypass grafting and no intervention was required in 2 patients. Cardiac magnetic resonance was performed 30 (4-140) days after the initial presentation. Most patients showed preserved left ventricular ejection fraction on CMR. No alternative reasons for the rise/fall of high-sensitive cardiac troponin T were found.

CONCLUSION

The absence of LGE on CMR in patients with Type 1 AMI is a new finding. While insufficient spatial resolution of LGE imaging, delayed CMR performance, spontaneous reperfusion, and coronary collaterals may provide some explanations, further investigations are required to fully understand this phenomenon.

Association Between History of Polymerase Chain Reaction-verified COVID-19 Infection and Outcomes of Subsequent ST-Elevation Myocardial Infarction

While the acute phase of coronavirus disease 2019 (COVID-19) is associated with worsening cardiac outcomes, it is unclear whether it affects the outcome of patients with ST-segment elevation myocardial infarction (STEMI) after the acute phase. In addition, while many studies compared the course of STEMI during the COVID-19 pandemic with the years before the outbreak, we evaluated the course of STEMI during the pandemic according to whether or not patients had history of COVID-19. Patients diagnosed with STEMI during the ongoing COVID-19 pandemic were included in the study. The Ministry of Health database was analyzed retrospectively, and patients with (n = 191) and without (n = 127) a history of polymerase chain reaction (PCR) confirmed COVID-19 infection were divided into groups. Clinical and angiographic characteristics were assessed. The rates of in-hospital major adverse cardiac events (MACE) were higher in those who had a history of PCR-verified COVID-19 infection. Angiographic and procedural findings indicating successful reperfusion were better in patients without a history of COVID-19. A history of COVID-19 infection (odds ratio 1.40, 95% confidence interval 1.25-1.60, P < .01) independently predicted MACE. A history of COVID-19 infection is a predictor of worse outcomes following coronary intervention and in-hospital MACE among patients with STEMI.

Assessment of Myocardial Viability and Risk Stratification in Coronary Chronic Total Occlusion: A Qualitative and Quantitative Stress Cardiac MRI Study

BACKGROUND

Indicators for assessing myocardial viability and risk stratification in patients with coronary chronic total occlusion (CTO) are still in the research stage.

PURPOSE

To use stress-MRI to assess myocardial function, blood perfusion, and viability and to explore their relationship with collateral circulation.

STUDY TYPE

Prospective.

SUBJECTS

Fifty-one patients with CTO in at least one major artery confirmed by X-ray coronary angiography (male: 46; age 55.2 ± 10.8 years).

FIELD STRENGTH/SEQUENCE

3.0T; TurboFlash, balanced steady-state free precession cine, and phase-sensitive inversion recovery sequences.

ASSESSMENT

Stress-MRI was used to obtain qualitative and quantitative parameters of segmental myocardium. Myocardial segments supplied by CTO target vessels were grouped according to the degree of collateral circulation assessed by radiographic coronary angiography (no/mild, moderate, or good). Depending on qualitative stress perfusion assessment and late gadolinium enhancement (LGE) extent, segments were also categorized as negative, viable, or trans-infarcted.

STATISTICAL TESTS

Independent sample Student's t-test, one-way analysis of variance (ANOVA) test, Mann-Whitney U test, Kruskal-Wallis test, Spearman correlation coefficient (r). P < 0.05 was considered statistically significant.

RESULTS

A total of 334 segments were supplied by CTO target vessels. The radial strain (RS), circumferential strain (CS), longitudinal strain (LS) of the negative, viable, and trans-infarcted regions showed a significant and stepwise impairment. Myocardial blood flow at rest was positively correlated with RS, CS, and LS (r = 0.42, 0.43, 0.38, respectively). Among the different collateral circulation, there were no significant differences in RS, CS, LS, and LGE volume (P = 0.788, 0.562, 0.122, 0.170, respectively), and there were also no statistically significant differences in the proportions of negative, viable, and trans-infarcted regions (P = 0.372).

DATA CONCLUSION

Myocardial perfusion obtained by stress-MRI combined with strain and LGE may comprehensively evaluate myocardial function and viability, and has potential to facilitate risk stratification of CTO.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 1.

Correlation between triglyceride glucose index and collateral circulation formation in patients with chronic total occlusion of coronary arteries in different glucose metabolic states

BACKGROUND

To investigate the correlation between triglyceride glucose index (TyG) and collateral circulation in patients with chronic total occlusion (CTO) of coronary arteries in different glucose metabolic states.

METHODS

A total of 681 patients who underwent coronary angiography between January 2020 and December 2021 to determine the presence of CTO lesions in at least one major coronary artery were retrospectively included in this study. Patients were categorized into a group with poor collateral circulation formation (Rentrop grade 0-1, n = 205) and a group with good collateral circulation formation (Rentrop grade 2-3, n = 476) according to the Rentrop scale. They were also categorized according to their glucose metabolism status: normal glucose regulation (NGR) (n = 139), prediabetes mellitus (Pre-DM) (n = 218), and diabetes mellitus (DM) (n = 324). Correlation between TyG index and collateral circulation formation was analyzed by logistic regression analysis and receiver operating characteristic (ROC) curves.

RESULTS

Among patients with CTO, TyG index was significantly higher in the group with poor collateral circulation formation than in the group with good collateral circulation formation. Logistic regression analysis showed that TyG index was an independent risk factor for poor collateral circulation formation (OR 5.104, 95% CI 3.323-7.839, P < 0.001). The accuracy of TyG index in predicting collateral circulation formation was evaluated by the ROC curve, which had an area under the curve of 0.779 (95% CI 0.738-0.820, P < 0.001). The restrictive cubic spline curves showed that the risk of poor collateral circulation formation in the Pre-DM and DM groups was initially flat and finally increased rapidly, except for the NGR group. TyG index was significantly associated with an increased risk of poor collateral circulation formation in the Pre-DM and DM groups.

CONCLUSIONS

TyG index was significantly associated with the risk of poor collateral circulation formation in patients with CTO, especially those with Pre-DM and DM.

Circulating secretoneurin level reflects angiographic coronary collateralization in stable angina patients with chronic total occlusion

OBJECTIVE

To investigate the association between circulating secretoneurin (SN) and angiographic coronary collateralization in stable angina patients with chronic coronary total occlusion (CTO).

METHODS

SN concentrations in serum were measured in 641 stable angina patients with CTO by radioimmunoassay. The status of coronary collaterals from the contra-lateral vessel was visually estimated using the Rentrop grading system, and was categorized into poor (grade 0 or 1) or good (grade 2 or 3) collateralization.

RESULTS

Serum SN levels were significantly higher in patients with good coronary collaterals compared to those with poor collaterals (175.23 ± 52.09 pmol/L vs. 143.29 ± 42.01 pmol/L, P < 0.001). Serum SN increased stepwise across Rentrop score 0 to 3 (P < 0.001), and increasing SN tertiles were associated with higher proportion of good coronary collateralization (OR, 1.907; 95% CI, 1.558 ~ 2.335, P < 0.001). After adjustment for confounding variables, serum SN (per tertile) remained an independent factor for predicting good coronary collaterals (OR, 1.870; 95% CI, 1.515 ~ 2.309; P < 0.001). Moreover, the diagnostic value of serum SN (per tertile) was consistent after stratifying patients based on gender, age, body mass index, hypertension, diabetes, history of smoking, severity of coronary artery disease and kidney function (OR: 1.511 ~ 2.680, P interaction ≥ 0.327).

CONCLUSION

Elevated circulating SN reflects good angiographic coronary collaterals in stable angina patients with CTO. The findings may provide insight into decision-making for these patients.

Effect of Fibroblast Growth Factor-21 Molecule on Coronary CollateralDevelopment

BACKGROUND

Collateral arteries provide an alternative source to the myocardium resulting from ischemia due to occlusive coronary artery disease and may help preserve myocardial function in the case of coronary artery disease (CAD). Although collateral development is so important, its pathophysiology has not been fully elucidated. Till now, no study has investigated the relationship between Fibroblast growth factor-21(FGF-21) and coronary collateral.

OBJECTIVE

This study aims to investigate the pathophysiology of coronary collateral development.

METHODS

In our study, which we planned as a case-control, 60 consecutive patients with ≥90 stenosis in at least one large coronary artery as a result of coronary angiography (CAG) and 30 patients with normal coronary angiography were included in the study cross-sectional. Demographic, echocardiographic and laboratory data were recorded. Coronary collateral circulation was evaluated using the Rentrop-Cohen method. FGF-21 levels were measured in all individuals.

RESULTS

In the analysis, no significant difference was observed between the two groups in basic biochemical parameters other than HDL (p>0.05 for all). FGF-21 level was statistically significantly higher in the patient group compared to the control group (p: 0.003). Also, the FGF-21 level was found to be statistically significantly higher in the good collateral circulation group than the poor (p:0.006). Univariate and multivariate logistic regression analysis was performed to predict the presence of collateral. We found that FGF-21(p=0.006), and C-reactive protein (p=0.020) predicted the presence of collateral independently.

CONCLUSION

Collateral formation and cardiac prognosis are closely related. Our study is the first to investigate the relationship between collateral formation and FGF-21. Our study showed that the FGF-21 level is an independent predictor of collateral formation. In addition, there was a significant difference between bad and good collateral formation regarding FGF-21 levels.

Prevalence of Collateral Typology in Coronary Chronic Total Occlusion and Its Impact on Percutaneous Intervention Performance

The presence of collateral channels providing distal blood supply is a distinctive characteristic of chronic total occlusion (CTO) lesions. However, data about the distinct baseline and procedural characteristics of each collateral subset are scarce. Accordingly, we sought to explore the procedural aspects specific for each collateral typology (ipsilateral collaterals [ICs], contralateral collaterals [CCs] or mixed) in CTO-percutaneous coronary intervention (PCI). A retrospective analysis of our CTO-PCI registry was performed to investigate the prevalence, procedural characteristics, and outcomes specific for each CTO-PCI subset, defined according to the inter-arterial connection anatomy. A total of 209 cases were included. Of the included cases, 45 (22%) and 92 (44%) patients displayed solely IC or CC, respectively, whereas in 72 (34%) both IC and CC were present (mixed). The procedural success rate was high (91.1%) and comparable among the different groups, despite greater lesion complexity in the CC group. The most frequent target vessel was the left circumflex in the IC group (51% of cases) and the right coronary artery in the CC (63%) and mixed (57%) groups. Among the IC cases, 42% showed a poor collateral connection function (2% and 10% for the CC and mixed group, respectively), and 46% showed a suboptimal collateral recipient artery filling (21% and 20% for the CC and mixed group, respectively). Most of the IC cases were performed using a single access (96%). In conclusion, the success and complication rates were comparable among the collateral typology groups, irrespective of the differences in the baseline and procedural characteristics. Phenotyping CTO as hereby proposed might be helpful for targeted procedural considerations.

S-nitrosylation of AMPKγ impairs coronary collateral circulation and disrupts VSMC reprogramming

Collateral circulation is essential for blood resupply to the ischemic heart, which is dictated by the contractile phenotypic restoration of vascular smooth muscle cells (VSMC). Here we investigate whether S-nitrosylation of AMP-activated protein kinase (AMPK), a key regulator of the VSMC phenotype, impairs collateral circulation. In rats with collateral growth and development, nitroglycerin decreases coronary collateral blood flow (CCBF), inhibits vascular contractile phenotypic restoration, and increases myocardial infarct size, accompanied by reduced AMPK activity in the collateral zone. Nitric oxide (NO) S-nitrosylates human recombinant AMPKγ1 at cysteine 131 and decreases AMP sensitivity of AMPK. In VSMCs, exogenous expression of S-nitrosylation-resistant AMPKγ1 or deficient NO synthase (iNOS) prevents the disruption of VSMC reprogramming. Finally, hyperhomocysteinemia or hyperglycemia increases AMPKγ1 S-nitrosylation, prevents vascular contractile phenotypic restoration, reduces CCBF, and increases the infarct size of the heart in Apoe-/- mice, all of which is rescued in Apoe-/-/iNOSsm-/- mice or Apoe-/- mice with enforced expression of the AMPKγ1-C130A mutant following RI/MI. We conclude that nitrosative stress disrupts coronary collateral circulation during hyperhomocysteinemia or hyperglycemia through AMPK S-nitrosylation.

An unusual cause of acute coronary syndrome: thrombosis of right coronary artery to right atrium fistula

Coronary arterial fistulae are rare, but it is one of the most common coronary artery anomalies. Most of the cases are asymptomatic in younger patients unless it is large and of haemodynamic significance. The incidence of thromboembolic complications usually increases with age. We report a case of a young male in his early 20s presenting with central chest pain. Coronary computed tomographic angiography revealed acute coronary syndrome due to a fistula between right coronary artery and right atrium occluded by thrombus. After discussion with coronary and congenital heart multidisciplinary team, a consensus was agreed that we should manage him conservatively with anticoagulant and antiplatelet therapy and a 3-month follow-up strategy that included repeating cardiac imaging. After a year, his anticoagulation and antiplatelet medication was discontinued.

Microvascular Complications Are Associated With Coronary Collateralization in Type 2 Diabetes and Chronic Occlusion

CONTEXT

Coronary collateral (CC) vessel development appears to be protective with regard to adverse cardiovascular events and survival in patients with coronary chronic total occlusion (CTO). The influence of type 2 diabetes mellitus (T2DM) on CC growth has been controversial. In particular, the role of diabetic microvascular complications (DMC) in determining coronary collateralization has not been elucidated.

OBJECTIVE

To investigate whether patients with DMC presented differences in CC vessel presence and grading as compared with patients without DMC.

METHODS

We conducted a single-center observational study, including consecutive T2DM patients, without previous cardiovascular history, undergoing a clinically indicated coronary angiography for chronic coronary syndrome (CCS) and angiographic evidence of at least one CTO. Patients were subdivided into 2 study groups according to the presence/absence of at least one DMC (neuropathy, nephropathy, or retinopathy). The presence and grading of angiographically visible CC development from the patent vessels to the occluded artery were assessed using the Rentrop classification.

RESULTS

We enrolled 157 patients (mean age 68.6 ± 9.8 years; 120 [76.4%] men). Patients with DMC (75 [47.8%]) had a higher prevalence of CC (69 [92.0%] vs 62 [75.6%], P = .006) and high-grade CC (55 [73.3%] vs 39 [47.6%], P = .001) compared with those without, and we found a positive association between the number of DMC in each patient and the prevalence of high-grade CC.

CONCLUSION

Among T2DM patients with coronary CTO, the presence of DMC was associated with a high CC development.

Immediate recruitment of dormant coronary collaterals can provide more than half of normal resting perfusion during coronary occlusion in patients with coronary artery disease

BACKGROUND

Dormant coronary collaterals are highly prevalent and clinically beneficial in cases of coronary occlusion. However, the magnitude of myocardial perfusion provided by immediate coronary collateral recruitment during acute occlusion is unknown. We aimed to quantify collateral myocardial perfusion during balloon occlusion in patients with coronary artery disease (CAD).

METHODS

Patients without angiographically visible collaterals undergoing elective percutaneous transluminal coronary angioplasty (PTCA) to a single epicardial vessel underwent two scans with 99mTc-sestamibi myocardial perfusion single-photon emission computed tomography (SPECT). All subjects underwent at least three minutes of angiographically verified complete balloon occlusion, at which time an intravenous injection of the radiotracer was administered, followed by SPECT imaging. A second radiotracer injection followed by SPECT imaging was performed 24 h after PTCA.

RESULTS

The study included 22 patients (median [interquartile range] age 68 [54-72] years. The perfusion defect extent was 19 [11-38] % of the LV, and the collateral perfusion at rest was 64 [58-67]% of normal.

CONCLUSION

This is the first study to describe the magnitude of short-term changes in coronary microvascular collateral perfusion in patients with CAD. On average, despite coronary occlusion and an absence of angiographically visible collateral vessels, collaterals provided more than half of the normal perfusion.

Angiographic Predictors of Viability During Intervention for a ST Elevation Myocardial Infarction

Objectives

This study aimed to identify angiographic features that would predict myocardial viability after coronary intervention for ST elevation myocardial infarction (STEMI).

Methods

This retrospective study included patients who attended Sultan Qaboos University Hospital, Muscat, Oman, between January and December 2019 with a STEMI.

Results

A total of 72 patients (61 male; mean age = 54.9 ± 12.7 years) were included in the study; 11 patients had evidence of non-viability on echocardiography. There were 13 patients with viable myocardium and 3 with non-viable myocardium who had a myocardial blush grade (MBG) of 2 or lower. Similarly, 10 patients with viability and 1 with non-viable myocardium had thrombolysis in myocardial infarction (TIMI) flow of 2 or lower in the infarct related artery (IRA). However, none of these were statistically significant. The TIMI flow in the IRA at the end of the procedure correlated with the MBG.

Conclusion

There were no clear angiographic features during primary angioplasty that could predict myocardial viability.

Clinical Outcome of Paclitaxel-Coated Balloon Angioplasty Versus Drug-Eluting Stent Implantation for the Treatment of Coronary Drug-Eluting Stent In-Stent Chronic Total Occlusion

AIMS

In-stent chronic total occlusion (IS-CTO) represents a unique challenge for percutaneous coronary intervention. Whether the optimal treatment for IS-CTO is angioplasty with paclitaxel-coated balloons (PCBs) or repeat stenting with drug-eluting stents (DESs) is unclear. We aimed to evaluate the long-term clinical outcome of PCB angioplasty and DES repeat stenting for DES IS-CTO.

METHODS

We retrospectively included patients with DES IS-CTO who underwent successful PCB angioplasty or DES repeat stenting from January 2016 to December 2019. The primary endpoints were major adverse cardiac events (MACEs), including cardiac death, myocardial infarction, and target lesion revascularization (TLR). Cox proportional hazards model was performed to compare the risk of MACEs between PCB angioplasty and DES repeat stenting, and to further explore the prognostic factors of patients with DES IS-CTO.

RESULTS

A total of 214 patients with DES IS-CTO were enrolled: 78 patients (36.4%) treated with PCB and 136 patients (63.6%) treated with DES respectively. The median follow-up was 1160 days, and MACEs were observed in 28.2% of patients with PCB angioplasty versus 26.5% of patients with DES repeat stenting (P = 0.784), mainly driven by TLR (21.8% vs. 19.9%, P = 0.735). There was no significant difference in the risk of MACEs between the PCB group and the DES group (hazard ratio [HR] 1.25, 95% confidence interval [CI] 0.64-2.46, P = 0.512). Multivariate Cox analysis revealed that chronic kidney disease and ≥ 3 stent layers in the lesion were independent predictors of MACEs, while switching to another antiproliferative drug was an independent protective factor (all P < 0.05).

CONCLUSIONS

PCB angioplasty was an effective alternative treatment strategy for DES IS-CTO, which had similar long-term outcomes to DES repeat stenting in contemporary practice, but both were accompanied by a high rate of long-term MACEs. Improving the poor prognosis of patients with DES IS-CTO remains a challenge.

Collateral grading systems in retrograde percutaneous coronary intervention of chronic total occlusions

BACKGROUND

The Japanese Channel (J-Channel) score was introduced to aid in retrograde percutaneous coronary intervention (PCI) of chronic total coronary occlusions (CTOs). The predictive value of the J-Channel score has not been compared with established collateral grading systems such as the Rentrop classification and Werner grade.

AIMS

To investigate the predictive value of the J-Channel score, Rentrop classification and Werner grade for successful collateral channel (CC) guidewire crossing and technical CTO PCI success.

METHODS

A total of 600 prospectively recruited patients underwent CTO PCI. All grading systems were assessed under dual catheter injection. CC guidewire crossing was considered successful if the guidewire reached the distal segment of the CTO vessel through a retrograde approach. Technical CTO PCI success was defined as thrombolysis in myocardial infarction flow grade 3 and residual stenosis <30%.

RESULTS

Of 600 patients, 257 (43%) underwent CTO PCI through a retrograde approach. Successful CC guidewire crossing was achieved in 208 (81%) patients. The predictive value of the J-Channel score for CC guidewire crossing (area under curve 0.743) was comparable with the Rentrop classification (0.699, p = 0.094) and superior to the Werner grade (0.663, p = 0.002). Technical CTO PCI success was reported in 232 (90%) patients. The Rentrop classification exhibited a numerically higher discriminatory ability (0.676) compared to the J-Channel score (0.664) and Werner grade (0.589).

CONCLUSIONS

The J-channel score might aid in strategic collateral channel selection during retrograde CTO PCI. However, the J-Channel score, Rentrop classification, and Werner grade have limited value in predicting technical CTO PCI success.

Do chronic total occlusive lesions affect patency of coronary bypass grafts to the right coronary artery?

OBJECTIVES

To evaluate the impact of chronic total occlusion (CTO) lesions on the patency of bypass grafts to the right coronary artery territory.

METHODS

Two hundred patients undergoing primary isolated coronary artery bypass grafting with revascularization to the right coronary artery territory between April 2015 and July 2022 were retrospectively analyzed. Study patients were divided into two groups according to their right coronary artery lesion: patients with CTO lesions (n  =  76) and those without CTO lesions (n  =  124). Graft flow of the right coronary artery territory was evaluated by intraoperative transit time flow measurement and patency of the bypass graft was evaluated by multidetector row computed tomography.

RESULTS

A total of 200 patients (76 patients with CTO and 124 patients without CTO) were included in this study. Intraoperative transit time flow measurement demonstrated that there was no significant difference in the median mean graft flow (30 ml/min vs. 25 ml/min; p  =  0.114), pulsatility index (2.1 vs. 2.4; p  =  0.079), and diastolic filling rate (65% vs. 64%; p  =  0.844) between patients with CTO and those without CTO. Postoperative multidetector row computed tomography demonstrated that the patency of bypass grafts to the right coronary artery territory was similar between the groups (94.7% in patients with CTO vs. 96.0% in those without CTO; p  =  0.733). In patients with CTO, the patency of bypass graft tended to be worse in subgroup with rich collateral blood flow (Rentrop grade 3).

CONCLUSIONS

Chronic total occlusion lesions do not affect the patency of bypass grafts to the right coronary artery territory.

Are Thiols Useful Biomarkers for Coronary Collateral Circulation in Patients with Stable Coronary Artery Disease?

Our aim was to investigate the relationship between thiol, which is the main component of the antioxidant system, and coronary collateral circulation (CCC). Our patients consisted of people with stable coronary artery disease (sCAD) and total occlusion in at least one vessel (n = 249). We divided the patients into two groups, good and poor, according to their CCC degree. We determined that DM, total thiol, and disulfide are independent predictors of poor CCC in multivariate logistic regression analysis (OR: 1.012, 95% CI: 1.008-1.017, p < 0.001; OR: 1.022, 95% CI: 1.000-1.044, p = 0.044; OR: 2.671, 95% CI: 1.238-5.761, p = 0.012, respectively). The ROC analysis showed a cut-off value of 328.7 for native thiol regarding the prediction of poor CCC, with 67.4% specificity and 78% sensitivity. For disulfide, it revealed a cut-off value of 15.1 regarding the prediction of poor CCC, with 57.9% specificity and 69.5% sensitivity. In this study, we detected that the patients with sCAD who developed poor CCC had lower levels of native thiol, total thiol, and disulfide compared to those with good CCC. The most interesting finding of our study is that CCC formation is an effective predictor of the antioxidant cascade rather than the inflammation cascade in sCAD patients.

Chronic Total Occlusion of the Left Main Coronary Artery With Preserved Left Ventricular Systolic Function Presenting as a Chronic Coronary Syndrome: A Case Report and Brief Review

The incidence of lesions involving the left main coronary artery (LMCA) during coronary angiography is approximately 5% to 8%. It usually presents with acute coronary syndrome and can be fatal. Total occlusion of the LMCA is rare, often accompanied by myocardial infarction and cardiogenic shock. We present an LMCA chronic total occlusion case in a 60-year-old female patient with chronic coronary syndrome. In our case, the LMCA was selectively visualized, and it was found to be occluded. The right coronary artery fed the entire left system through the collateral network. The patient had no risk of coronary artery disease other than hypertension. Successful coronary artery bypass grafting was performed without any complications.

Impact of Lipoprotein (a) on Long-Term Outcomes in Patients With Acute Myocardial Infarction

BACKGROUND

Lipoprotein (a) (Lp(a)) is a complex circulating lipoprotein, and there is increasing evidence it is a risk factor for atherosclerotic cardiovascular disease (ASCVD). This study aimed to investigate the influence of Lp(a) serum levels on long-term outcomes after acute myocardial infarction (AMI).

METHODS AND RESULTS

Between January 2015 and January 2018, we enrolled 262 patients with AMI who underwent coronary angiography within 24 h of the onset of chest pain and had available Lp(a) data enabling subdivision into 2 groups: high Lp(a) (≥32 mg/dL: n=76) and low Lp(a) (<32 mg/dL: n=186). The primary endpoint was major adverse cardiac events (MACE), which was defined as a composite of cardiac death, nonfatal MI, and readmission for heart failure. Multivariate Cox regression analysis was performed to identify the predictors of MACE. The incidence of MACE was significantly higher in the high Lp(a) group than in the low Lp(a) group (32.8% vs. 19.6%, P=0.004). Multivariate analysis showed that Lp(a) ≥32 mg/dL was an independent predictor of MACE (hazard ratio 2.84, 95% confidence interval 1.25-6.60, P=0.013).

CONCLUSIONS

High Lp(a) levels were associated with worse long-term outcomes after AMI, so Lp(a) may be useful for risk assessment.

Impact of right coronary artery dominance on the long-term mortality in the patients with acute total/subtotal occlusion of unprotected left main coronary artery

BACKGROUND

Patients with a right dominant coronary artery anatomy account for a significant proportion of acute myocardial infarction cases, and this condition is associated with a better prognosis. However, there are limited data on the impact of coronary dominance on patients with acute total/subtotal occlusion of unprotected left main coronary artery (ULMCA).

METHODS

This study aimed to assess the impact of right coronary artery (RCA) dominance on long-term mortality in patients with acute total/subtotal occlusion of the ULMCA. From a multicenter registry, 132 cases of consecutive patients who had undergone emergent percutaneous coronary intervention (PCI) due to acute total/subtotal occlusion of the ULMCA were reviewed.

RESULTS

Patients were classified into two groups according to the size of their RCA (dominant RCA group, n = 29; non-dominant RCA group, n = 103). Long-term outcomes were examined according to the presence of dominant RCA. Cardiopulmonary arrest (CPA) occurred in 52.3 % of patients before revascularization. All-cause death was significantly lower in the dominant RCA group than in the non-dominant RCA group. In the Cox regression model, dominant RCA was an independent predictor of all-cause death, as well as total occlusion of ULMCA, collateral from RCA, chronic kidney disease, and CPA. Patients were further analyzed according to the degree of stenosis of the ULMCA; patients with non-dominant RCA and total occlusive ULMCA had the worst outcome compared with the other groups.

CONCLUSIONS

A dominant RCA might improve long-term mortality in patients with acute total/subtotal occlusion of the ULMCA who were treated with PCI.

Efficiency of the Guide Extension Catheter-Facilitated Tip-in Technique in the Recanalization of Coronary Chronic Total Occlusion

Background

The tip-in technique, which involves advancing an antegrade microcatheter cross the lesion over a retrograde guidewire, is an elaborated maneuver in the recanalization of coronary chronic total occlusion (CTO). We seek to assess the efficiency of a guide extension catheter-facilitated tip-in technique in comparison to the traditional retrograde approach, which is accomplished by an externalization wire.

Methods

Thirty-three CTO patients successfully revascularized using guide extension catheter-facilitated "tip-in" were included and matched with another 33 patients by J-CTO score and operators, whose CTO was recanalized using an externalized wire. The manipulation time from the first retrograde wire entering the antegrade guide to the first antegrade balloon inflation in the occlusion was calculated.

Results

Compared with the wire-externalization group, the manipulation time in the tip-in group was significantly shortened [389s; interquartile range (IQR), 272-478 vs 706s; IQR, 560-914; p < 0.001]. There was a trend in decreasing total operation time and radiation dose, but it did not reach statistical significance.

Conclusion

Guide extension catheter-facilitated tip-in is an efficient method to achieve the recanalization of CTO in a retrograde way, which would be pivotal when the retrograde microcatheter could not be advanced into the antegrade guide catheter.

Role of circulating CD14++CD16+ monocytes and VEGF-B186 in formation of collateral circulation in patients with hyperacute AMI

Introduction

Collateral formation is insufficient in some patients with acute myocardial infarction (AMI). Peripheral blood CD14++CD16⁺ monocytes (intermediate monocytes; IM) and vascular endothelial growth factors (VEGFs) are associated with formation of collateral circulation.

Methods

We enrolled 49 patients with AMI who underwent emergency percutaneous transluminal coronary intervention (PCI) (Group A) and 27 patients underwent delayed PCI 1 week after AMI (Group B). The percentage of circulating IM and levels of VEGFs in circulation were determined on day 8th. Left ventricular ejection fraction (LVEF) was measured 3 months after AMI.

Results

The peripheral levels of IM and serum VEGF levels on day 8th were significantly higher in patients with well-developed collateral circulation in Group A than those in Group B. The levels of circulating VEGFs in the collateral circulation (+) subgroup in Group B were lower than those in the collateral circulation (-) subgroup. Moreover, the serum VEGF-B186 levels positively correlated with IM.

Conclusions

Hyperacute collateral formation in patients with AMI correlated with a higher percentage of CD14++CD16⁺ monocytes and VEGF-B186 levels in the circulation, which was associated with milder left ventricular remodeling. The regulation of CD14++CD16⁺ monocytes and VEGF-B may be critical to the formation of collateral circulation and to healing AMI.

Coronary Collateral Circulation: A New Predictor of Mortality in Heart Transplant Recipients With Allograft Vasculopathy

Coronary collateral arteries (CCAs) are anastomotic channels between vessels; although beneficial in atherosclerosis, their role in heart transplantation (HT) recipients is underinvestigated. CCAs initially develop as microcirculation and cardiac allograft vasculopathy (CAV), promoting immune-dependent proliferative angiogenic response, and play a role in their development. In our hypothesis, ischemia induced by coronary microvascular dysfunction (CMD) triggers the development of CCAs, which are, in turn, less functional as affected by CAV themselves.

Methods

One hundred twenty-one patients receiving HT at our institution were retrospectively evaluated and were included if transthoracic echocardiography with coronary flow velocity reserve (CFVR) assessment and coronary angiography were performed. CMD was defined as CFVR of ≤2.5. Patients with CAV were enrolled, and their angiograms were reviewed to evaluate the presence of CCAs. Cardiovascular mortality was assessed as the main clinical outcome.

Results

Forty patients were found to have CCAs. Patients with CCAs have lower CFVR than those without CCAs (2.22 ± 0.72 versus 2.69 ± 0.92;P = 0.003), reflecting in different rates of CMD in the 2 groups (72.5% versus 37%; P < 0.001). CMD is associated with higher CAV grades (P < 0.001), which are also associated with CCAs (P < 0.001). Patients with poorly developed CCAs have lower CFVR (P < 0.001). At multivariable analysis, CMD (P = 0.008) and higher CAV grades (P = 0.005) are independent predictors of CCAs. During the median follow-up time of 10.2 (6.6-13.3) y, patients with CCAs have been found to have higher mortality than those without CCAs (57.5% versus 32.1%; P = 0.007). CCAs are associated with a lower probability of survival also in patients with CMD (P < 0.001) and are independent predictors of mortality (P < 0.001).

Conclusions

Our results demonstrate an interplay between CAV, CMD, and CCAs. We confirm that CAV is associated with CMD, and we show, for the first time, that CMD is associated with CCAs. CCAs are pathophysiologically associated with more severe graft vasculopathy and independently predict mortality after HT.

Infarct-Related Artery as a Donor of Collaterals in ST-Segment-Elevation Myocardial Infarction With Concomitant Chronic Total Occlusion: Challenge of the Double-Jeopardy Thesis

BACKGROUND In ST-segment-elevation myocardial infarction (STEMI), a concomitant chronic total occlusion (CTO) in a non-infarct-related artery (NIRA) is associated with adverse outcome. In the case of the infarct-related artery (IRA) as a donor vessel for collaterals to the CTO, the IRA occlusion may lead to an acute threat to both the immediate IRA and the collaterally supplied CTO area, which has been described as a double-jeopardy effect. METHODS AND RESULTS We investigated the role of preformed intercoronary collaterals to the CTO originating from either the IRA or NIRA. Data were obtained from 2 hospitals participating in the prospective FITT-STEMI (Feedback Intervention and Treatment Times in ST-Segment Elevation Myocardial Infarction) study. From a total cohort of 2102 patients with acute STEMI, 93 patients had single-vessel CTO in an NIRA and well-developed intercoronary collaterals to the CTO. In-hospital mortality differed significantly with respect to the origin of the collaterals. Mortality was 15.2% with collaterals originating from the NIRA, 29.4% with a collateral origin from the IRA proximal to the acute STEMI occlusion, and 3.3% with a collateral origin from the IRA distal to the acute occlusion (P=0.044). A multivariate regression model confirmed that a proximal collateral origin had a significant higher mortality compared with a branching in the distal position from the acute STEMI occlusion (P=0.027; odds ratio = 20.8 [95% CI, 1.4-304.1]). CONCLUSIONS In STEMI with CTO in an NIRA, a CTO collateralization from the IRA distal to the acute occlusion is associated with a better prognosis. This finding challenges the double-jeopardy assumption as the main cause of adverse outcome in STEMI with CTO in an NIRA. REGISTRATION URL: https://www.clinicaltrials.gov; Unique identifier: NCT00794001.

The association of serum uric acid/albumin ratio with the development of coronary collateral circulation in patients with chronic total occluded coronary arteries

Introduction: Coronary collateral circulation (CCC) develops in chronic total occluded (CTO) vessels and protects the myocardium against ischemia in addition to the improvement of cardiac functions. Poor CCC is related to adverse cardiac events as well as poor prognosis. Serum uric acid/albumin ratio (UAR) has emerged as a novel marker associated with poor cardiovascular outcomes. We aimed to investigate whether there was an association between UAR and poor CCC in CTO patients. Methods: This study was comprised of 212 patients with CTO (92 with poor CCC and 120 with good CCC). All patients were graded based on Rentrop scores to poor CCC (Rentrop scores 0 and 1) and good CCC (Rentrop scores 2 and 3). Results: Poor CCC patients had higher frequencies of diabetes mellitus, triglyceride levels, Syntax and Gensini scores, uric acid, and UAR and lower lymphocyte, high-density lipoprotein cholesterol, and ejection fraction when compared to good CCC patients. UAR was an independent predictor of poor CCC in CTO patients. Furthermore, UAR had a better discriminative ability for patients with poor CCC from good CCC compared to serum uric acid and albumin. Conclusion: Based on the results of the study, the UAR could be used to detect poor CCC in CTO patients.

Collateral presence and extent do not predict myocardial viability and ischemia in chronic total occlusions: A stress-CMR study

BACKGROUND

Well-developed collaterals are assumed as a marker of viability and ischemia in chronic total occlusions (CTO). We aim to correlate viability and ischemia with collateral presence and extent in CTO patients by cardiac magnetic resonance (CMR).

METHODS

Multicentre study of 150 CTO patients undergoing stress-CMR, including adenosine if normal systolic function, high-dose-dobutamine for patients with akinetic/>2 hypokinetic segments and EF ≥35%, otherwise low-dose-dobutamine (LDD); all patients underwent late gadolinium enhancement (LGE) imaging. Viability was defined as mean LGE transmurality ≤50% for adenosine, as functional improvement for dobutamine-stress-test, ischemia as ≥1.5 segments with perfusion defects outside the scar zone.

RESULTS

Rentrop 3/CC 2 defined well-developed (WD, n = 74) vs poorly-developed collaterals (PD, n = 76). Viability was equally prevalent in WD vs PD: normo-functional myocardium with ≤50% LGE in 52% vs 58% segments, p = 0.76, functional improvement by LDD in 48% vs 52%, p = 0.12. Segments with none, 1-25%,26-50%,51-75% LGE showed viability by LDD in 90%,84%,81%,61% of cases, whilst in 12% if 76-100% LGE (p < 0.01). There was no difference in WD vs PD for ischemia presence (74% vs 75%, p = 0.99) and extent (2.7 vs 2.8 segments, p = 0.77).

CONCLUSIONS

In a large cohort of CTO patients, presence and extent of collaterals did not predict viability and ischemia by stress-CMR. Scar extent up to 75% LGE was still associated with viability, whereas ischemia was undetectable in 25% of patients, suggesting that the assessment of CTO patients with CMR would lead to a more comprehensive evaluation of viability and ischemia to guide revascularization.

Study of blood rheological parameters and NO in coronary artery disease patients with and without collaterals

BACKGROUND

In coronary artery disease (CAD), an alternative way of improvement of blood circulation in the ischemic area of the myocardium is coronary collateral circulation. Our study aimed to investigate the rheological parameters of blood and nitric oxide (NO) content in patients with various degrees of collateral development and the likelihood of the influence of blood fluidity on collateral angiogenesis.

METHODS

We studied patients with stable CAD who underwent elective coronary angiography and a control group with the same mean age. We investigated patients with different degrees of developing collaterals and those without them. In studied patients, the blood plasma viscosity, aggregability, and deformability of erythrocytes, as the main indicators of blood rheology. We recorded content of stable metabolic end products of nitric oxide (NOx).

RESULTS

Results of the studies showed that in the blood of studied patients with CAD erythrocyte aggregation was increased and NO content decreased compared to the control level; NO content was as lower, as less was the number of developed collaterals was recorded.

CONCLUSION

In this work, the role of the aggregation ability of erythrocytes and the endothelial origin of NO in the direct and feedback regulatory mechanism of angiogenesis in patients with CAD are discussed.

Clinical and electrocardiographic features in acute total left main coronary artery occlusion without collateral circulation

BACKGROUNDS

Study concerning the clinical features, electrocardiogram (ECG) findings and outcomes in patients presenting with acute total occlusion of left main coronary artery (LM) without collateral circulation is limited.

METHODS

25 patients with acute total LM occlusion without collateral circulation by emergency coronary angiography, from muti-center registry, were retrospectively studied. The clinical and angiographic characteristics, ECG and in-hospital mortality were reviewed.

RESULTS

Nineteen patients (76%) presented with cardiogenic shock. Twelve (60%, 12/20) patients had coronary slow flow or no reflow phenomenon after primary percutaneous coronary intervention (PCI). The in-hospital mortality rate was 88% (n = 22). All the patients presented with ST-segment elevation myocardial ischemia (STEMI) pattern, mostly involving leads I, aVL, V2, V3, V4, V5 and ST-segment depression in leads II, III and aVF.

CONCLUSIONS

Acute total LM occlusion without collateral circulation portends high in-hospital mortality. Anterior ST elevation in the precordial leads from V2 to V4 through V6, and ST elevation in leads I and aVL, accompanying with ST depression in the inferior leads is associated with acute total LM occlusion without collateral circulation.