Impact of Collateral Circulation on Survival in ST-Segment Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention With a Concomitant Chronic Total Occlusion

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.

Chronic total occlusion in non-ST elevation myocardial infarction - A multi-centre observational study

OBJECTIVES

To evaluate the characteristics and outcomes of patients with a chronic total occlusion (CTO) in a Non-ST Elevation Myocardial Infarction (NSTEMI) cohort.

BACKGROUND

There is limited data on the clinical characteristics, revascularisation strategies and outcomes of patients presenting with a NSTEMI and a CTO.

METHODS

Retrospective analysis of a six-centre percutaneous coronary intervention (PCI) registry in the UK between January 2015 and December 2020 was performed. Patients with a NSTEMI with and without a CTO were compared for baseline characteristics and outcomes.

RESULTS

There were 17,355 NSTEMI patients in total of whom 1813 patients had a CTO (10.4 %). Patients with a CTO were more likely to be older (CTO: 67.8 (±11.5) years vs. no CTO: 67.2 (±12) years, p = 0.04), male (CTO: 81.1 % vs.71.9 %, p < 0.0001) with a greater prevalence of cardiovascular risk factors. All-cause mortality at 30 days: HR 2.63, 95 % CI 1.42-4.84, p = 0.002 and at 1 year: HR: 1.87, 95 % CI 1.25-2.81, p = 0.003 was higher in the CTO cohort. CTO patients who underwent revascularisation were younger (Revascularisation 66.4 [±11.7] years vs. no revascularisation 68.4 [±11.4] years, p = 0.001). Patients with failed CTO revascularisation had lower survival (HR 0.21, 95 % CI 0.10-0.42, p < 0.0001). The mean time to revascularisation was 13.4 days. There was variation in attempt at CTO revascularisation between the 6 centres for (16 % to 100 %) with success rates ranging from 65 to 100 %.

CONCLUSIONS

In conclusion, the presence of a CTO in NSTEMI patients undergoing PCI was associated with worse in-hospital and long-term outcomes.

Refined metabolite profiling in the collateral circulation of chronic total occlusion of coronary arteries: Insights from a metabolomics investigation

Background and aims

To investigate the disparities in coronary collateral circulation (CCC) and peripheral serum metabolites among patients presenting with chronic total occlusion (CTO) of the coronary arteries, a non-targeted metabolic approach was employed.

Methods

A cohort of 22 patients diagnosed with CTO of coronary arteries in the context of coronary heart disease (CHD) was selected for blood sample collection from CCC and peripheral arteries. The patients were categorized into two groups, namely CTO-C and CTO-P. The Waters UPLC I-Class Plus is combined with the Q Exactive high-resolution mass spectrometer for metabolite separation and detection. The acquired raw data from mass spectrometry is subsequently imported into Compound Discoverer 3.2 software for comprehensive analysis, which seamlessly integrates the BGI Metabolome Database (BMDB), mzCloud database, and ChemSpider online database. Subsequently, the identified differential metabolites were subjected to a metabolic pathway enrichment analysis, as documented in the Kyoto Encyclopedia of Genes and Genomes (KEGG) database.

Results

A total of 403 differential metabolites were identified in CCC and peripheral serum samples from patients with CTO of coronary arteries in CHD. Compared to the CTO-P group, the CTO-C group exhibited decreased levels of metabolites such as Testosterone, dehydroepiandrosterone (DHA), deoxyacetone, while demonstrating increased levels of metabolites including Progesterone, androstanone, l-threonine. The biosynthesis pathway of steroid hormones emerges as the key metabolic pathway significantly associated with differential metabolites.

Conclusions

Through metabolomics analysis, distinct differences in the CCC and peripheral serum metabolites have been identified among patients with CTO of coronary artery. Notably, a significant association between the steroid hormone biosynthesis pathway and CCC has been observed.

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.

Good coronary collateral circulation is not associated with better prognosis in patients with chronic total occlusion, regardless of treatment strategy

OBJECTIVE

This study aimed to assess the effects of coronary collateral circulation (CCC) on the prognosis of patients with chronic total occlusion (CTO) under different treatment strategies.

METHODS

We analyzed a total of 1124 patients who were diagnosed with CTO and divided them into groups with good CCC (grade 2 to 3, n = 539) or poor CCC (grade 0 to 1, n = 531). The primary outcome was cardiac death during follow-up; the secondary outcome was major adverse cardiovascular events (MACEs). We also performed subgroup analyses in groups with and without CTO revascularization (CTO-R and CTO-NR, respectively), and sensitivity analyses excluding patients who received failed CTO-PCI to further investigate the effect of CCC.

RESULTS

During a median follow-up duration of 23 months, we did not detect any significant differences between the good CCC group and the poor CCC group in terms of cardiac death (4.2% vs 4.1%; adjusted hazard ratio [HR], 1.01; 95% confidence interval [CI], 0.56-1.83; p = 0.970) and MACEs (23.6% vs 23.2%; adjusted HR, 1.07; 95% CI, 0.84-1.37; p = 0.590). Subgroup analyses according to CTO revascularization showed similar results. In addition, we observed no differences in sensitivity analyses when patients who received failed CTO-PCI were excluded.

CONCLUSION

Good CCC was not associated with a lower risk of cardiac death or MACEs among patients with CTO, regardless of whether the patients received CTO revascularization treatment.

Advances in neovascularization after diabetic ischemia

With the high incidence of diabetes around the world, ischemic complications cause a serious influence on people’s production and living. Neovascularization plays a significant role in its development. Therefore, neovascularization after diabetic ischemia has aroused attention and has become a hot spot in recent years. Neovascularization is divided into angiogenesis represented by atherosclerosis and arteriogenesis characterized by coronary collateral circulation. When mononuclear macrophages successively migrate to the ischemia anoxic zone after ischemia or hypoxia, they induce the secretion of cytokines, such as vascular endothelial growth factor and hypoxia-inducible factor, activate signaling pathways such as classic Wnt and phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt) pathways, trigger oxidative stress response, activate endothelial progenitor cells or enter the glycolysis or lactic acid process and promote the formation of new blood vessels, remodeling them into mature blood vessels and restoring blood supply. However, the hypoglycemic condition has different impacts on neovascularization. Consequently, this review aimed to introduce the mechanisms of neovascularization after diabetic ischemia, increase our un-derstanding of diabetic ischemic complications and their therapies and provide more treatment options for clinical practice and effectively relieve patients’ pain. It is believed that in the near future, neovascularization will bring more benefits and hope to patients with diabetes.

The predictive value of the triglyceride-glucose index for cardiovascular events in patients with coronary chronic total occlusion

BACKGROUND

Chronic total occlusion (CTO) of the coronary artery is a difficult problem in clinical practice. The triglyceride-glucose (TyG) index is an effective risk predictor of cardiovascular risk. However, the relationship between the TyG index and the prognosis of CTO patients remains unstudied. Thus, the present study aimed to investigate the relationship between the TyG index and cardiovascular risk in CTO patients.

METHODS

This was a single-centre, retrospective cohort study. We retrospectively enrolled 652 patients with CTO lesions diagnosed by angiography and who underwent revascularization through PCI. Patients were routinely followed up for 24 months unless meeting the endpoint. The primary endpoint was the composite of all-cause death, nonfatal myocardial infarction, unplanned revascularization, and nonfatal ischaemic stroke. To test the association of the TyG index with cardiovascular risk, the categorized TyG index and Cox proportional hazards regression models were utilized.

RESULTS

A total of 652 patients were enrolled in the final analysis (male: 83.7%, age: 58.2 ± 10.49 years). The average TyG index was 8.8 ± 0.57. CTO PCIs were procedurally successfully completed in 503 (77.15%) patients. During the follow-up period of 22.8 ± 3.84 months, 73 (11.19%) major adverse cardiovascular and cerebral events (MACCEs) occurred. When fully adjusted, there was a 2.09-fold risk for MACCEs among patients with the highest TyG index compared with those with the lowest TyG index [T2 vs. T1: hazard ratio (HR) 1.24, 95% confidence interval (CI) 0.65-2.38, P = 0.057; T3 vs. T1: HR 2.09, 95% CI 1.14-3.86, P = 0.018; P for trend = 0.036]. The restricted cubic spline (RCS) analysis showed that the HR for MACCEs increased as the TyG index increased over 8.71 [HR per standard deviation (SD) 1.740, 95% CI 1.23-2.46, P = 0.002]. The risk of MACCEs increased with increasing tertiles of TyG index in successful CTO PCI patients and nondiabetes mellitus (DM) patients (P < 0.05) but not in patients with failed CTO PCI and DM patients.

CONCLUSION

The study revealed that the TyG index had significant relevance to cardiovascular risk in CTO patients and suggests that the TyG index is feasible for predicting cardiovascular risk in CTO patients.

Association between the triglyceride glucose index and coronary collateralization in coronary artery disease patients with chronic total occlusion lesions

Background

Recent studies have substantiated the role of the triglyceride glucose (TyG) index in predicting the prognosis of coronary artery disease (CAD) patients, while no relevant studies have revealed the association between the TyG index and coronary collateralization in the event of coronary chronic total occlusion (CTO). The current study intends to explore whether, or to what extent, the TyG index is associated with impaired collateralization in CAD patients with CTO lesions.

Methods

The study enrolled 1093 CAD patients undergoing cardiac catheterization for at least one CTO lesion. Data were collected from the Beijing Anzhen Hospital record system. The degree of collaterals was determined according to the Rentrop classification system. The correlation between the TyG index and coronary collateralization was assessed.

Results

Overall, 318 patients were included in a less developed collateralization (Rentrop classification 0-1) group. The TyG index was significantly higher in patients with impaired collateralization (9.3±0.65 vs. 8.8±0.53, P<0.001). After adjusting for various confounding factors, the TyG index remained correlated with the occurrence of impaired collateralization, with odds ratios (ORs) of 1.59 and 5.72 in the T2 and T3 group compared with the first tertile group (P<0.001). In addition, subgroup analysis showed that higher TyG index values remained strongly associated with increased risk of less developed collateralization. To compare the risk assessment efficacy for the formation of collateralization between the TyG index and other metabolic abnormality indicators, an area under the receiver-operating characteristic (ROC) curve (AUC) was obtained. A significant improvement in the risk assessment performance for impaired collateralization emerged when adding the TyG index into a baseline model.

Conclusions

The increased TyG index is strongly associated with less developed collateralization in CAD patients with CTO lesions and its risk assessment performance is better than single metabolic abnormality indicators.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-021-01574-x.

Glycemic Control Status and Long-Term Clinical Outcomes in Diabetic Chronic Total Occlusion Patients: An Observational Study

Background

Whether good glycemic control can result in clinical benefits for diabetic chronic total occlusion (CTO) patients is still a matter of debate.

Methods

We studied 1029 diabetic CTO patients. Based on one-year glycosylated hemoglobin A (HbA1c) levels, we assigned the patients into 2 groups: HbA1c<7% group (n = 448) and HbA1c ≥ 7% group (n = 581). We further subdivided the patients into the successful CTO revascularization (CTO-SR) and nonsuccessful CTO revascularization (CTO-NSR) groups. Kaplan-Meier analysis and Cox regression before and after propensity score matching were used to compare major adverse cardiovascular events (MACE) and other endpoints.

Results

There were no significant differences between the groups in terms of most endpoints in the overall patients. After propensity score-matched analysis, patients with HbA1c < 7.0 tended to be superior in terms of MACE, which was mainly attributed to repeat revascularization but the other endpoints. Furthermore, the benefit of the HbA1c < 7 group was more prominent among patients with CTO-NSR in terms of MACE, repeat revascularization, and target vessel revascularization (TVR); and the improvement of the HbAc1 < 7 group was more prominent among patients without chronic heart failure (CHF) (P=0.027).

Conclusions

HbA1c < 7.0 was associated with a reduced incidence of MACE, which was mainly attributed to a reduction in repeat revascularization. Good glycemic control can improve diabetic CTO patients' clinical prognosis, especially in CTO-NSR patients.

The value of fragmented QRS in predicting the prognosis of chronic total occlusion patients with myocardial infarction history undergoing percutaneous coronary intervention: A 24-months follow-up study

BACKGROUND

Fragmented QRS (fQRS) is a marker of local myocardial scar. This study aimed to analyze the relationship between fQRS and coronary collateral circulation (CCC) and evaluate the predictive value of fQRS for long-term clinical outcomes among patients with chronic total occlusion (CTO) and prior myocardial infarction (MI) who underwent percutaneous coronary intervention (PCI).

METHODS

A total of 862 patients with a definite history of MI who had one CTO coronary artery and underwent PCI between 2013 and 2018 were continuously analyzed. Patients were divided into group A (no Q wave and fQRS, n = 206), group B (fQRS, n = 265), group C (Q wave, n = 391). All patients were followed up for 2 years.

RESULTS

The incidence rate of major adverse cardiovascular events (MACE) in group B was significantly lower than in group C (group B vs. C: 7.2% vs. 11.3%, P = 0.043). The percentage of good CCC was 94.2%, 88.3%, and 82.9% in group A, B, and C (p < .001), respectively. The improvement of cardiac function in group B and A were more significant than in group C. Multivariate Cox regression analysis showed fQRS was an independent protective factor of MACE after PCI within 2 years in CTO patients with prior MI (RR = 0.668, 95% CI [0.422-0.917], p = .001).

CONCLUSION

fQRS is an independent protective factor of prognosis in patients with prior MI and one CTO vessel who underwent PCI, presenting with a higher rate of good CCC, less occurrence of MACE, and better heart function than in Q wave patients.

Impact of age on reperfusion success and long-term prognosis in ST-segment elevation myocardial infarction - A cardiac magnetic resonance imaging study

Background

Coronary collateral circulation and conditioning from remote ischemic coronary territories may protect culprit myocardium in the elderly, and younger STEMI patients could suffer from larger infarcts. We evaluated the impact of age on myocardial salvage and long-term prognosis in a contemporary STEMI cohort.

Methods

Of 1603 included STEMI patients 807 underwent cardiac magnetic resonance. To assess the impact of age on infarct size and left ventricular ejection fraction (LVEF) as well as the composite endpoint of death and re-hospitalization for heart failure we stratified the patients by an age cut-off of 60 years.

Results

Younger STEMI patients had smaller final infarcts (10% vs. 12%, P = 0.012) and higher final LVEF (60% vs. 58%, P = 0.042). After adjusting for multiple potential confounders age did not remain significantly associated with infarct size and LVEF. During 4-year follow-up, the composite endpoint occurred less often in the young (3.2% vs. 17.2%; P < 0.001) with a univariate hazard ratio of 5.77 (95% CI, 3.75–8.89; p < 0.001). Event estimates of 4 subgroups (young vs. elderly and infarct size beyond vs. below median) showed a gradual increase in the occurrence of the composite endpoint depending on both age and acute infarct size (log-rank p < 0.001).

Conclusion

Having a STEMI after entering the seventh decade of life more than quadrupled the risk of future death or re-hospitalization for heart failure. Risk of death and re-hospitalization depended on both advanced age and infarct size, albeit no substantial difference was found in infarct size, LVEF and salvage potential between younger and elderly patients with STEMI.

The Use of Artificial Hypoxia in Endurance Training in Patients after Myocardial Infarction

The presence of a well-developed collateral circulation in the area of the artery responsible for the infarction improves the prognosis of patients and leads to a smaller area of infarction. One of the factors influencing the formation of collateral circulation is hypoxia, which induces angiogenesis and arteriogenesis, which in turn cause the formation of new vessels. The aim of this study was to assess the effect of endurance training conducted under normobaric hypoxia in patients after myocardial infarction at the level of exercise tolerance and hemodynamic parameters of the left ventricle. Thirty-five patients aged 43–74 (60.48 ± 4.36) years who underwent angioplasty with stent implantation were examined. The program included 21 training units lasting about 90 min. A statistically significant improvement in exercise tolerance assessed with the cardiopulmonary exercise test (CPET) was observed: test duration (p < 0.001), distance covered (p < 0.001), HRmax (p = 0.039), maximal systolic blood pressure (SBPmax) (p = 0.044), peak minute ventilation (VE) (p = 0.004) and breathing frequency (BF) (p = 0.044). Favorable changes in left ventricular hemodynamic parameters were found for left ventricular end-diastolic dimension LVEDD (p = 0.002), left ventricular end-systolic dimension LVESD (p = 0.015), left ventricular ejection fraction (LVEF) (p = 0.021), lateral e’ (p < 0.001), septal e’ (p = 0.001), and E/A (p = 0.047). Endurance training conducted in hypoxic conditions has a positive effect on exercise tolerance and the hemodynamic indicators of the left ventricle.

Impact of chronic total occlusion and revascularization strategy in patients with infarct-related cardiogenic shock: A subanalysis of the culprit-shock trial

BACKGROUND

The impact of coronary artery chronic total occlusion (CTO) and its management with percutaneous coronary intervention (PCI) in the setting of myocardial infarction (MI) related cardiogenic shock (CS) remains unclear.

METHODS

This is a pre-specified analysis from the culprit-lesion-only PCI vs multivessel PCI in CS (CULPRIT-SHOCK) trial which randomized patients presenting with MI and multivessel disease complicated by CS to a culprit-lesion-only or immediate multivessel PCI strategy. CTO was defined by central core-laboratory evaluation. The independent associations between the presence of CTO and adverse outcomes at 30 days and 1 year were assessed using multivariate logistics models.

RESULTS

A noninfarct related CTO was present in 157 of 667 (23.5%) analyzed patients. Patients presenting with CTO had more frequent diabetes mellitus or prior PCI but less frequently presented with ST segment elevation MI as index event. The presence of CTO was associated with higher rate of death at 30 days (adjusted Odds ratio 1.63; 95% confidence interval [CI] 1.01-2.60). Rate of death at 1 year was also increased but did not reach statistical significance (adjusted Odds ratio 1.62; 95%CI 0.99-2.66). Compare to immediate multivessel PCI, a strategy of culprit-lesion-only PCI was associated with lower rates of death or renal replacement therapy at 30 days in patients with and without CTO (Odds ratio 0.79 95%CI 0.42-1.49 and Odds ratio 0.67 95%CI 0.48-0.96, respectively), without significant interaction (P = .68).

CONCLUSIONS

In patients with MI-related CS and multivessel disease, the presence of CTO is associated with adverse outcomes while a strategy of culprit-lesion-only PCI seems beneficial regardless of the presence of CTO.

Prognostic Impact of Percutaneous Coronary Intervention of Chronic Total Occlusion in Acute and Periprocedural Myocardial Infarction

Coronary chronic total occlusion (CTO) has gained increasing clinical attention as the most advanced form of coronary artery disease. Prior studies already indicated a clear association of CTO with adverse clinical outcomes, especially in patients with acute myocardial infarction (AMI) and concomitant CTO of the non-infarct-related coronary artery (non-IRA). Nevertheless, the prognostic impact of percutaneous coronary intervention (PCI) of CTO in the acute setting during AMI is still controversial. Due to the complexity of the CTO lesion, CTO-PCI leads to an increased risk of complications compared to non-occlusive coronary lesions. Therefore, this review outlines the prognostic impact of CTO-PCI in patients with AMI. In addition, the prognostic impact of periprocedural myocardial infarction caused by CTO-PCI will be discussed.

Incomplete protective effect of coronary collateral circulation for acute myocardial infarction patients

The short-term and long-term effects of coronary collateral circulation (CCC) discovered after acute myocardial infarction (AMI) are still debatable. This retrospective cohort study aimed to explore the clinical significance of CCC for AMI patients.A consecutive series of 323 AMI patients with CCC and 1339 AMI subjects without CCC were enrolled, most of them received percutaneous coronary intervention after AMI. Comparisons between CCC subjects and non-CCC population and between CCC sub-groups were applied regarded to basic clinical characteristics, stenosis extent indicated by Gensini score, myocardial infarction size estimated by peak concentration of troponin I (TnI), and left ventricular function evaluated by peak value of N-terminal pro-brain natriuretic peptide (NT-proBNP). Multiple linear regressions for NT-proBNP and TnI, and Kaplan-Meier curves for 5-years' main cardiovascular event (MACE) were also analyzed.CCC might provide incomplete protection by preventing excessive myocardial infarction but not a poorer heart function during AMI and CCC had no obvious protective effect on 5-years' MACE for AMI patients. More attentions should be paid to heart function for CCC patients during AMI.

Native Coronary Collateral Microcirculation Reserve in Rat Hearts

Background We occasionally noticed that native collateral blood flow showed a recessive trend in the early stages of acute myocardial infarction in rats, which greatly interferes with the accurate assessment of native collateral circulation levels. Here, we sought to recognize the coronary collateral circulation system in depth, especially the microcirculation part, on this basis. Methods and Results In this study, we detected native collateral flow with positron emission tomography perfusion imaging in rats and found that the native flow is relatively abundant when it is initially recruited. However, this flow is extremely unstable in the early stage of acute myocardial infarction and quickly fails. We used tracers to mark the collateral in an ischemic area and a massive preformed collateral network was labeled. The ultrastructures of these collateral microvessels are flawed, which contributes to extensive leakage and consequent interstitial edema in the ischemic region. Conclusions An unrecognized short-lived native coronary collateral microcirculation reserve is widely distributed in rat hearts. Recession of collateral blood flow transported by coronary collateral microcirculation reserve contributes to instability of native collateral blood flow in the early stage of acute myocardial infarction. The immature structure determines that these microvessels are short-lived and provide conditions for the development of early interstitial edema in acute myocardial infarction.

Peristenotic Collateral Circulation in Atherosclerotic Renovascular Disease: Association With Kidney Function and Response to Treatment

The significance of peristenotic collateral circulation (PCC) development around a stenotic renal artery is unknown. We tested the hypothesis that PCC is linked to loss of kidney function and recovery potential in patients with atherosclerotic renovascular disease (ARVD). Thirty-four patients with ARVD were assigned to medical-therapy with or without revascularization based on clinical indications. The PCC was visualized using multidetector computed tomography and defined relative to segmental arteries in patients with essential hypertension. PCC number before and 3 months after treatment was correlated with various renal parameters. Thirty-four stenotic kidneys from 30 patients were analyzed. PCC number correlated inversely with kidney volume. ARVD-stenotic kidneys with baseline PCC (collateral ARVD [C-ARVD], n=13) associated with elevated 24-hour urine protein and stenotic kidney vein level of tumor necrosis factor-α, lower single-kidney volume and blood flow, and greater hypoxia than in stenotic kidneys with no PCC (no collateral ARVD [NC-ARVD], n=17). Revascularization (but not medical-therapy alone) improved stenotic kidney function and reduced inflammation in both NC-ARVD and C-ARVD. In C-ARVD, revascularization also increased stenotic kidney volume, blood flow, and oxygenation to levels comparable to NC-ARVD, and induced PCC regression. However, revascularization improved systolic blood pressure, plasma renin activity, and filtration fraction only in NC-ARVD. Therefore, patients with C-ARVD have greater kidney dysfunction, atrophy, hypoxia, and inflammation compared with patients with NC-ARVD, suggesting that PCC does not effectively protect the stenotic kidney in ARVD. Renal artery revascularization improved in C-ARVD stenotic kidney function, but not hypertension or renin-angiotensin system activation. These observations may help direct management of patients with ARVD.

Lipoprotein(a) as a marker for predicting coronary collateral circulation in patients with acute myocardial infarction

Aim: The aim of the present study was to examine the predictive value of lipoprotein(a) (Lp[a]) levels for coronary collateral circulation (CCC) in patients with acute myocardial infarction (AMI). Method & methods: A total of 409 consecutive patients with AMI were enrolled for this study. Patients were divided into two groups according to rentrop grades assessed by coronary angiography: bad (n = 277) and good CCC group (n = 132). Result: Patients with bad CCC had a higher level of Lp(a) than that with good CCC (median Lp[a] 219.1 vs 122.0 mg/l). The area under the receiver-operating characteristic curves of Lp(a) in predicting bad CCC was 0.647 (95% CI: 0.592–0.702) with the cut-off value of 199.0 mg/l. Conclusion: Our data firstly suggested that Lp(a) might be a useful marker for CCC after AMI.

NFAT5 promotes arteriogenesis via MCP-1-dependent monocyte recruitment

Studies have demonstrated that nuclear factor of activated T cells 5 (NFAT5) is not only a tonicity‐responsive transcription factor but also activated by other stimuli, so we aim to investigate whether NFAT5 participates in collateral arteries formation in rats. We performed femoral artery ligature (FAL) in rats for hindlimb ischaemia model and found that NFAT5 was up‐regulated in rat adductors with FAL compared with sham group. Knockdown of NFAT5 with locally injection of adenovirus‐mediated NFAT5‐shRNA in rats significantly inhibited hindlimb blood perfusion recovery and arteriogenesis. Moreover, NFAT5 knockdown decreased macrophages infiltration and monocyte chemotactic protein‐1 (MCP‐1) expression in rats adductors. In vitro, with interleukin‐1β (IL‐1β) stimulation and loss‐of‐function studies, we demonstrated that NFAT5 knockdown inhibits MCP‐1 expression in endothelial cells and chemotaxis of THP‐1 cells regulated by ERK1/2 pathway. More importantly, exogenous MCP‐1 delivery could recover hindlimb blood perfusion, promote arteriogenesis and macrophages infiltration in rats after FAL, which were depressed by NFAT5 knockdown. Besides, NFAT5 knockdown also inhibited angiogenesis in gastrocnemius muscles in rats. Our results indicate that NFAT5 is a critical regulator of arteriogenesis and angiogenesis via MCP‐1‐dependent monocyte recruitment, suggesting that NFAT5 may represent an alternative therapeutic target for ischaemic diseases.

Effect of coronary collateral circulation on the prognosis of elderly patients with acute ST-segment elevation myocardial infarction treated with underwent primary percutaneous coronary intervention

Investigate the effect of coronary collateral circulation (CCC) on the prognosis of elderly patients with acute ST-segment elevation myocardial infarction (STEMI) and acute total occlusion (ATO) of a single epicardial coronary artery.Three hundred forty-six advanced-age patients (age ≥60 years) with STEMI and ATO who underwent primary percutaneous coronary intervention (PCI) were enrolled in this study. According to the Rentrop grades, the patients were assigned to the poor CCC group (Rentrop grade 0-1) and good CCC group (Rentrop grade 2-3).Multivariate logistic regression analysis revealed that poor coronary collateral circulation was an independent factor for Killip class ≥2 (odds ratio [OR]: -1.559; 95% confidence interval [CI]: 1.346-2.378; P = .013), the use of an intra-aortic balloon pump (IABP) (OR: -1.302; 95% CI: 0.092-0.805; P = .019), and myocardial blush grade (MBG) 3 (OR: 1.516; 95% CI: 2.148-9.655; P < .001). We completed a 12-month follow-up, during which 52 patients (15.0%) were lost to follow-up and 19 patients (5.5%) died. Univariate analysis (Kaplan-Meier and log-rank tests) suggested that poor CCC had a significant effect on all-cause mortality (P = .046), while multivariate analysis (Cox regression analysis) indicated that CCC had no statistically significant effect on all-cause mortality (P = .089) after the exclusion of other confounding factors. After excluding the influence of other confounding factors, this study showed that the mortality rate increased by 26.9% within 1 year for every 1-hour increment of time of onset. The mortality rate in patients with Killip class ≥2 was 8.287 times higher than that in patients with Killip class 0 to 1. The mortality rate in patients over 75 years was 8.25 times higher than that in patients aged 60 to 75 years. The mortality rate in patients with myocardial blush grade 3 (MBG 3) was 5.7% higher than that in patients with MBG 0-2.The conditions of CCC in the acute phase had no significant direct effect on all-cause mortality in patients, but those with good CCC had a higher rate of MBG 3 after primary PCI and a lower rate of Killip ≥2.

Potential Role of Vitamin C Intracoronary Administration in Preventing Cardiac Injury After Primary Percutaneous Coronary Intervention in Patients with ST-Elevation Myocardial Infarction

Objective:

The aim of the present study was to determine the effects of intravenous (IV) and intracoronary administration of Vitamin C on the incidence of periprocedural myocardial injury in patients undergoing primary percutaneous coronary intervention (PCI).

Methods:

In this prospective, double-blind, randomized clinical trial, that was conducted in Tehran Heart Center, Iran, between October 2016 and March 2017, 252 patients undergoing primary PCI were enrolled to receive either 3 g of IV Vitamin C before PCI and 100 mg of intracoronary Vitamin C during PCI in addition to the routine treatment (n = 126) or just the routine treatment (n = 126). Cardiac biomarkers were measured before and then 6 and 12 h postprocedurally. We determined the occurrence of contrast-induced acute kidney injury (CI-AKI), according to the levels of serum creatinine, neutrophil gelatinase-associated lipocalin, and platelet activation biomarker (P-selectin) in a subset of 119 patients before and 6 h after PCI.

Findings:

In the patients who received Vitamin C, the serum levels of troponin T after 12 h and creatine kinase-MB after 6 h were significantly lower than those in the placebo group (P = 0.003 andP = 0.00, respectively). CI-AKI occurred in 6 (4.7%) patients in the study group and 8 (6.3%) patients in the control group; there was no significant reduction in CI-AKI in the study group. In addition, the two groups were statically similar as regards the changes in the level of P-selectin.

Conclusion:

In primary PCI patients, the prophylactic use of IV and intracoronary Vitamin C can confer additional clinical benefits such as cardioprotection.

Does the effectiveness of recanalization of chronic occlusion depend on the location of the obstruction?

Introduction

In past studies, it has been questioned whether success of recanalization of chronic total occlusion (CTO) depends on the location of the occlusion - the circumflex artery (Cx) was considered as the most difficult to open.

Aim

To determine whether the effectiveness of recanalization of CTO depends on the location of the obstruction.

Material and methods

From January 2011 to January 2016, a single operator dedicated to chronic total occlusions performed in our center 357 procedures on 337 patients.

Results

Among 337 patients included in the study, 83.4% were male. Mean age was 62.8 ±9.3 years. Most of the patients had hypertension (86.4%) and hyperlipidemia (99.4%), and 28.8% of them had diabetes. The most frequently opened artery was the right coronary artery (RCA; 52.4%), followed by the left anterior descending artery (LAD; 29.4%), and last the Cx (18.2%). The mean J-CTO score was comparable between the three groups. The success rate of recanalization of CTO was similar for all arteries: 84.5% in the RCA, 81.9% in the LAD and 89.2% in the Cx (overall p = 0.437). Neither procedural complications nor adverse events depended on the location of the CTO.

Conclusions

Our study shows the same efficacy of CTO procedures of all epicardial arteries. We did not observe that effectiveness of recanalization of CTO depends on the location of the obstruction.

Impact of collateralisation to a concomitant chronic total occlusion in patients with ST-elevation myocardial infarction: a subanalysis of the EXPLORE randomised controlled trial

Objective

The impact on cardiac function of collaterals towards a concomitant chronic total coronary occlusion (CTO) in patients with ST-elevation myocardial infarction (STEMI) has not been investigated yet. Therefore, we have evaluated the impact of well-developed collaterals compared with poorly developed collaterals to a concomitant CTO in STEMI.

Methods and results

In the EXPLORE trial, patients with STEMI and a concomitant CTO were randomised to either CTO percutaneous coronary intervention (PCI) or no-CTO PCI. Collateral grades were scored angiographically using the Rentrop grade classification. Left ventricular ejection fraction (LVEF) and left ventricular end-diastolic volume (LVEDV) at 4 months were measured using cardiac magnetic resonance imaging. Well-developed collaterals (Rentrop grades 2-3) to the CTO were present in 162 (54%) patients; these patients had a significantly higher LVEF at 4 months (46.2±11.4% vs 42.1±12.7%, p=0.004) as well as a trend for a lower LVEDV (208.2±55.7 mL vs 222.6±68.5 mL, p=0.054) when compared with patients with poorly developed collaterals to the CTO. There was no significant difference in the total amount of scar in the two groups. Event rates were statistically comparable between patients with well-developed collaterals and poorly developed collaterals to the CTO at long-term follow-up.

Conclusions

In patients with STEMI and a concomitant CTO, the presence of well-developed collaterals to a concomitant CTO is associated with a better LVEF at 4 months. However, this effect on LVEF did not translate into improvement in clinical outcome. Therefore, the presence of well-developed collaterals is important, but should not solely guide in the clinical decision-making process regarding any additional revascularisation of a concomitant CTO in patients with STEMI.

Clinical trial registration

NTR1108.

Evaluation of the Impact of a Chronic Total Coronary Occlusion on Ventricular Arrhythmias and Long-Term Mortality in Patients With Ischemic Cardiomyopathy and an Implantable Cardioverter-Defibrillator (the eCTOpy-in-ICD Study)

Background

Previous studies report conflicting results about a higher incidence of ventricular arrhythmias in patients with a chronic total coronary occlusion (CTO). We aimed to investigate this association in a large cohort of implantable cardioverter defibrillator patients with long‐term follow‐up.

Methods and Results

All consecutive patients from 1992 onwards who underwent implantable cardioverter defibrillator implantation for ischemic cardiomyopathy at the Leiden University Medical Center were evaluated. Coronary angiograms were reviewed for the presence of a CTO. The occurrence of ventricular arrhythmias and survival status at follow‐up were compared between patients with and patients without a CTO. A total of 722 patients constitute the study cohort (age 66±11 years; 84% males; 74% primary prevention, median left ventricular ejection fraction 30% [first–third quartile: 25–37], 44% received a cardiac resynchronization therapy defibrillator). At baseline, 240 patients (33%) had a CTO, and the CTOs were present for at least 44 (2–127) months. The median follow‐up duration was 4 (2–6) years. On long‐term follow‐up, CTO patients had a higher crude appropriate device therapy rate (37% versus 27%, P=0.010) and a lower crude survival rate (51% versus 67%, P<0.001) compared with patients without a CTO. Corrected for baseline characteristics including left ventricular ejection fraction, the presence of a CTO was an independent predictor for appropriate device therapy.

Conclusions

The presence of a CTO in implantable cardioverter defibrillator patients was associated with more appropriate device therapy and worse prognosis at long‐term follow‐up. Further investigation is warranted regarding a potential beneficial effect of CTO revascularization on the incidence of ventricular arrhythmias.

Effect of Coronary Collaterals on Prognosis in Patients Undergoing Primary Percutaneous Coronary Intervention for Acute ST-Segment Elevation Myocardial Infarction: A Meta-Analysis

The impact of coronary collaterals on the prognosis in patients with acute ST-segment elevation myocardial infarction (STEMI) in the era of coronary revascularization remains controversial. The purpose of this meta-analysis was to investigate the effect of coronary collateral on clinical outcomes, especially mortality (≥6 months), in patients undergoing primary percutaneous coronary intervention (PCI) for STEMI. Eligible observational studies were selected by searching PubMed, EMBASE, and Cochrane Library up to August 9, 2017. Overall, 14 observational studies involving 10 411 patients were included. Coronary collaterals were found to reduce the risk of long-term mortality (≥6 months; risk ratio [RR]: 0.65, 95% confidence interval [CI]: 0.55-0.76) as well as in-hospital plus 30-day mortality (RR: 0.61, 95% CI: 0.47-0.78) in patients undergoing PCI for STEMI. In addition, pooling the risk-adjusted or propensity-matched data showed a significant reduction in long-term mortality (RR: 0.68, 95% CI: 0.49-0.95) and in-hospital plus 30-day mortality (RR: 0.27, 95% CI: 0.13-0.55) in patients with collateral circulation. However, no significant difference was found in the risk of recurrent myocardial infarction and target vessel revascularization between the 2 groups. Therefore, it was found that coronary collaterals have a beneficial effect on long-term survival (≥6 months) as well as in-hospital plus 30-day survival in patients undergoing primary PCI for STEMI.

Improved recovery of regional left ventricular function after PCI of chronic total occlusion in STEMI patients: a cardiovascular magnetic resonance study of the randomized controlled EXPLORE trial

BACKGROUND

The Evaluating Xience and left ventricular function in PCI on occlusiOns afteR STEMI (EXPLORE) trial did not show a significant benefit of percutaneous coronary intervention (PCI) of the concurrent chronic total occlusion (CTO) in ST-segment elevation myocardial infarction (STEMI) patients on global left ventricular (LV) systolic function. However a possible treatment effect will be most pronounced in the CTO territory. Therefore, we aimed to study the effect of CTO PCI compared to no-CTO PCI on the recovery of regional LV function, particularly in the CTO territory.

METHODS

Using cardiovascular magnetic resonance (CMR) we studied 180 of the 302 EXPLORE patients with serial CMR (baseline and 4 months follow-up). Segmental wall thickening (SWT) was quantified on cine images by an independent core laboratory. Dysfunctional segments were defined as SWT < 45%. Dysfunctional segments were further analyzed by viability (transmural extent of infarction (TEI) ≤50%.). All outcomes were stratified for randomization treatment.

RESULTS

In the dysfunctional segments in the CTO territory recovery of SWT was better after CTO PCI compared to no-CTO PCI (ΔSWT 17 ± 27% vs 11 ± 23%, p = 0.03). This recovery was most pronounced in the dysfunctional but viable segments(TEI < 50%) (ΔSWT 17 ± 27% vs 11 ± 22%, p = 0.02). Furthermore in the CTO territory, recovery of SWT was significantly better in the dysfunctional segments in patients with Rentrop grade 2-3 collaterals compared to grade 0-1 collaterals to the CTO (16 ± 26% versus 11 ± 24%, p = 0.04).

CONCLUSION

CTO PCI compared with no-CTO PCI is associated with a greater recovery of regional systolic function in the CTO territory, especially in the dysfunctional but viable segments. Further research is needed to evaluate the use of CMR in selecting post-STEMI patients for CTO PCI and the effect of regional LV function recovery on clinical outcome.

TRIAL REGISTRATION

Trialregister.nl NTR1108 , Date registered NTR: 30-okt-2007.