Bone marrow cells contribute to seven different endothelial cell populations in the heart.

Understanding the mechanisms underlying vascular regeneration in the heart is crucial for developing novel therapeutic strategies for myocardial ischemia. This study investigates the contribution of bone marrow-derived cells to endothelial cell populations in the heart, and their role in cardiac function and coronary circulation following repetitive ischemia (RI). Chimeric rats were created by transplanting BM cells from GFP female rats into irradiated male recipients. After engraftment chimeras were subjected to RI for 17 days. Vascular growth was assessed from recovery of cardiac function and increases in myocardial blood flow during LAD occlusion. After sorting GFP+ BM cells from heart and bone of Control and RI rats, single-cell RNA sequencing was implemented to determine the fate of BM cells. Our in vivo RI model demonstrated an improvement in cardiac function and myocardial blood flow after 17 days of RI with increased capillary density in the rats subjected to RI compared to Controls. Single-cell RNA sequencing of bone marrow cells isolated from rats' hearts identified distinct endothelial cell (EC) subpopulations. These ECs exhibited heterogeneous gene expression profiles and were enriched for markers of capillary, artery, lymphatic, venous, and immune ECs. Furthermore, BM-derived ECs in the RI group showed an angiogenic profile, characterized by upregulated genes associated with blood vessel development and angiogenesis. This study elucidates the heterogeneity of bone marrow-derived endothelial cells in the heart and their response to repetitive ischemia, laying the groundwork for targeting specific subpopulations for therapeutic angiogenesis in myocardial ischemia.

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.

A very rare interarterial communication: total occlusion of right coronary artery with antegrade collateral supply from left circumflex artery through conus branch.

PURPOSE: The purpose of the present case report is to describe an extremely rare and unusual coronary interarterial communication. METHODS: A 65-year-old female patient admitted with acute coronary syndrome underwent a coronary angiography performed with Judkins technique to obtain standard angiographic views. RESULTS: We have demonstrated a very rare interarterial communication traversing an unusual retroaortic path between the body of left circumflex artery and the conus branch of the right coronary artery. CONCLUSION: Coronary interarterial communications are rarely encountered; however, may fulfill important tasks in the coronary circulation. Therefore, invasive cardiologists and cardiovascular surgeons should be aware of their presence.

Prognostic implications of the rapid recruitment of coronary collaterals during ST elevation myocardial infarction (STEMI): a meta-analysis of over 14,000 patients.

Acute coronary collateralisation of an infarct-related arterial (IRA) territory may be identified during angiography for ST elevation myocardial infarction (STEMI). Whether the presence or absence of these collaterals affects outcomes remains uncertain. A search of EMBASE, MEDLINE and Cochrane Library, using the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines was conducted to identify studies which reported on the association between coronary collaterals and in-hospital and longer term mortality, left ventricular ejection fraction (LVEF), risk of repeat acute myocardial infarction (AMI) and repeat revascularisation. Patients with Rentrop grade 0 or 1 were defined as poor collaterals whilst those with Rentrop grade two or three were defined as those with robust collaterals. Studies were eligible if they included patients ≥ 18 years of age who had immediate coronary angiography for STEMI. Included studies were observational which recorded the degree of collateral blood flow to the IRA. Two investigators reviewed all citations using a predefined protocol with final consensus for all studies, the data from which was then independently entered to ensure fidelity of results. Inverse variance random effects model for the meta-analysis along with risk of bias assessment was performed. 20 studies with a total of 14,608 patients were identified and included in the analysis. Patients with robust collaterals had lower mortality (OR 0.55, 95% CI 0.48-0.64), both in-hospital (OR 0.47, 95% CI 0.35-0.63) and longer term (OR 0.58, 95% CI 0.46-0.75). Patients with robust collaterals also had a higher mean LVEF (SMD 0.23, 95% CI 0.10-0.37). There was no difference in the rates of AMI or repeat revascularisation between patients with robust or poor collaterals. The presence of robust collaterals during STEMI is associated with reduced in-hospital and longer term mortality and improved left ventricular function. These findings have implications for prognostication and identifying patients who require close monitoring following STEMI.

Both surgical and percutaneous revascularization improve prognosis in patients with a coronary chronic total occlusion (CTO) irrespective of collateral robustness.

The impact of surgical or percutaneous coronary revascularization on prognosis in patients with a chronic total occlusion (CTO) remains uncertain. Particularly, whether revascularization of those with robust coronary collaterals improves prognosis is unknown. The objective of this study was to determine the predictors and prognostic impact of revascularization of a CTO, and to determine the clinical impact of robust coronary collaterals. Patients with a CTO diagnosed on coronary angiography between Jul 2010 and Dec 2019 were included in this study. Management strategy of the CTO was defined as percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG) or medical management. The degree of collateral robustness was determined by the Rentrop grading classification. Demographic, angiographic and clinical outcomes were recorded. A total of 954 patients were included in the study, of which 186 (19.5%) patients underwent CTO PCI, 296 (31.0%) patients underwent CABG and 472 (49.5%) patients underwent medical management of the CTO. 166 patients (17.4%) had Rentrop grade zero or one collaterals, 577 (60.5%) patients had Rentrop grade two and 211 (22.1%) had Rentrop grade three collaterals. The independent predictors of medical management of the CTO were older age, greater stenosis in the donor vessel, an emergent indication for angiography, a non-LAD CTO and female sex. The degree of collateral robustness was not associated with long-term mortality, while patients who were revascularized either through CABG or PCI had a significantly lower mortality compared to medical management alone (p < 0.0001). In patients with a CTO, the presence of robust collaterals is not associated with prognosis, while both surgical and percutaneous revascularization is associated with improved prognosis. Further research into the optimal revascularization strategy for a CTO is required.

Influence of Obstructive Sleep Apnoea Severity on Coronary Collateral Recruitment During Coronary Occlusion.

PURPOSE: Obstructive sleep apnoea (OSA) which results in hypoxia may affect the ability to recruit coronary collaterals. The aim of this study was to determine whether the severity of OSA affects collateral recruitment in patients with total coronary occlusions. METHODS: Patients with total coronary artery occlusion were reviewed. Records from the sleep investigation laboratory were reviewed to identify those patients who had undergone diagnostic polysomnography. Robust coronary collaterals were those with Rentrop grade 2 or 3 collaterals. RESULTS: Sixty-four patients with a total coronary occlusion had polysomnography performed, of whom 60 patients had OSA. Thirty-two patients (53.3%) had poor collaterals, whilst 28 (46.7%) had robust collaterals. Twenty-four (40%) patients had mild OSA, 10 (16.7%) had moderate OSA and 26 (43.3%) had severe OSA. Patients with robust collaterals were more likely to be males (96.4% vs 74.3%, p < 0.05) and have a history of hypercholesterolaemia (88.9% vs 51.6%, p < 0.01). Patients with robust collaterals had a lower apnoea-hypopnoea index (13.6 vs 45.5, p < 0.05), a higher MinSaO2 (85.4% vs 79.8%, p < 0.05), less time SaO2 < 90% (0 min vs 30.4 min, p < 0.05) and lower oxygen desaturation index (6.9 vs 26.8, p < 0.05). Those with moderate OSA had a higher mean Rentrop grade (1.6 ± 0.3) than those with mild OSA (1.5 ± 1.1) and severe OSA (0.6 ± 0.2). CONCLUSION: The presence of more severe OSA is associated with poorer coronary collateral recruitment in patients with total coronary artery occlusion. The effect of treatment of OSA on subsequent ability to recruit collaterals and other cardioprotective mechanisms requires further research.

Influence of Obstructive Sleep Apnoea on Outcomes in Patients With ST Elevation Myocardial Infarction (STEMI): the Role of the Coronary Collateral Circulation.

BACKGROUND: Obstructive sleep apnoea (OSA) occurs frequently in patients with coronary artery disease, with associated intermittent hypoxia a possible stimulus for coronary collateral recruitment through ischaemic preconditioning. We sought to determine whether OSA affects recruitment of coronary collaterals and prognosis of patients presenting with ST elevation myocardial infarction (STEMI). METHODS: Patients with a STEMI undergoing percutaneous coronary intervention (PCI) from July 2010 to December 2019 were reviewed. Electronic medical records were accessed to determine documented patient history of OSA. Patients with robust collaterals were defined as Rentrop Grade 2 or 3. RESULTS: 1,863 patients were included, of which 143 (7.7%) patients had documented evidence of OSA in their health record. Patients with OSA had a higher body mass index (BMI) (30.2 kg/m2 vs 27 kg/m2, p<0.0001), greater rate of hypertension (61.1% vs 45.1%, p<0.0001), hypercholesterolaemia (47.4% vs 38.4%, p<0.05) and diabetes mellitus (22.6% vs 15.9%, p<0.05). Patients with OSA were more likely to have robust coronary collaterals (OR: 2.2 [95% CI: 1.5-3.2]) and a lower rate of left ventricular (LV) impairment (50.7% vs 63.1%, p<0.01), a higher LV ejection fraction (50.3% vs 46.7%, p<0.0001) and a lower peak troponin-I level (26,452 ng/L vs 39,469 ng/L, p<0.01). There were no differences in rates of in-hospital or longer term mortality, in patients with OSA compared to those without. CONCLUSIONS: Patients with documented OSA presenting with STEMI appear to have more robust coronary collaterals observed on angiography which likely mediates lower myocardial necrosis. Broader implications of this finding on treatment require further investigation.

Spontaneous coronary collateral recruitment in patients with recurrent ST elevation myocardial infarction (STEMI).

The spontaneous recruitment of acute coronary collaterals in the setting of an ST elevation myocardial infarction (STEMI) is seen frequently in those patients undergoing primary percutaneous coronary intervention (pPCI) and is associated with improved clinical outcomes. However, it is unknown whether in patients who present with a recurrent STEMI, the degree of collateral recruitment remains the same as in the index procedure. We reviewed all patients presenting to our tertiary centre with a STEMI undergoing primary or rescue percutaneous coronary intervention (PCI) from July 2010 until December 2018. We identified patients who presented with a recurrent STEMI following their index procedure. We defined patients with poor collateral recruitment as Rentrop grade 0 or 1, whilst patients with robust collateral recruitment as Rentrop grade 2 or 3. Of the 1795 patients who were identified, there were 27 cases in 25 patients who presented with a repeat STEMI following their index procedure. The median time between cases was 12.8 days (IQR 2.3-589.5 days). Compared to the index case, there was no statistically significant difference in the degree of collateral recruitment in recurrent presentations (Z = - 0.378, p = 0.70). In those patients presenting more than 6 months following the index procedure, the median time between cases was 654.5 days (IQR 479.5-1151.9). There was no difference in the degree of collateral recruitment in recurrent presentations (Z = 0.000, p = 1.0). Cases which had poorer collateral recruitment in recurrent presentations were less likely to be current smokers (0% vs 50%, p < 0.001) and less likely to have diabetes (0% vs 27.3%, p < 0.05) The recruitment of spontaneous coronary collaterals remains constant in recurrent STEMI presentations suggesting an innate biological process rather than merely a manifestation of alteration of haemodynamic blood flow. Further investigations to identify these processes is required.

The impact of coronary chronic total occlusion percutaneous coronary intervention upon donor vessel fractional flow reserve and instantaneous wave-free ratio: Implications for physiology-guided PCI in patients with CTO.

OBJECTIVE: To investigate the immediate and short term impact of right coronary artery (RCA) chronic total coronary occlusion (CTO) percutaneous coronary intervention (PCI) upon collateral donor vessel fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR). BACKGROUND: CTO PCI influences collateral donor vessel physiology, making the indication and/or timing of donor vessel revascularization difficult to determine. METHODS: In patients with RCA CTO, FFR, iFR, and collateral function index (FFRcoll ) were measured in LAD and LCx pre-CTO PCI, immediately post and at 4 month follow-up. RESULTS: 34 patients underwent successful PCI. In the predominant donor vessel immediately post PCI, FFR, and FFRcoll did not change (0.76 ± 0.12 to 0.75 ± 0.13, P = 0.267 and 0.31 ± 0.10 vs. 0.34 ± 0.11, P = 0.078), but iFR increased significantly (0.86 ± 0.10 to 0.88 ± 0.10, P = 0.012). At follow-up, there was a significant increase in predominant donor FFR and iFR (0.76 ± 0.12 to 0.79 ± 0.11, P = 0.047 and 0.86 ± 0.10 to 0.90 ± 0.07, P = 0.003), accompanied by a significant reduction in FFRcoll (0.31 ± 0.10 to 0.18 ± 0.07 P < 0.0001). These changes resulted in a reclassification of the predominant donor vessel from ischemic to nonischemic in 18% (FFR) and 25% (iFR) of the cases, respectively. CONCLUSIONS: Successful recanalization of an RCA CTO resulted in a modest but statistically significant increase in the predominant donor vessel immediately post CTO PCI in the case of iFR and at 4-month follow-up for FFR and iFR compared to pre-PCI with a concomitant reduction in collateral function.

Retrograde recanalization of a nonchronic total occlusion lesion.

The use of the retrograde approach to treat chronic total occlusion (CTO) has improved overall success rate in this lesion subgroup. Its use to treat complex non-CTO lesions unable to be revascularized by an antegrade approach has not been described. We report a case of the use of the retrograde approach to recanalize a non-CTO lesion under Impella support in a patient with critical stenosis and poor left ventricular function. The retrograde approach may be an alternate pathway in selected non-CTO lesions where the antegrade has been unsuccessful.

The presence of angiographic collaterals in non-ST elevation myocardial infarction is a predictor of long-term clinical outcomes.

OBJECTIVES: To determine whether the presence of angiographic coronary collaterals is a predictor of long-term clinical outcomes in patients with non-ST elevation myocardial infarction (NSTEMI). BACKGROUND: The presence of coronary collaterals on angiography provides prognostic information in patients with STEMI, but it is unknown whether they provide prognostic information in patients with NSTEMI. METHODS: This was a prospective cohort study of 931 consecutive patients undergoing coronary angiography of which 269 (29%) had a NSTEMI. Baseline characteristics, angiographic details, and long-term clinical outcomes including death, recurrent MI, coronary artery bypass graft surgery (CABG), percutaneous coronary intervention (PCI), stroke, and congestive heart failure (CHF) were collected. Each clinical outcome as well as the combined endpoint of death, recurrent MI, CABG, PCI stroke and CHF was compared in subjects with and without collaterals. RESULTS: At one year, individuals with collaterals had significantly increased rates of the combined endpoint compared with those without (25% vs. 16%, P = 0.0001). On multivariate analysis, the presence of collaterals was a strong predictor of the combined endpoint of death, recurrent MI, CABG, PCI, stroke and CHF (HR 1.95, CI 95% 1.08-3.52; P = 0.027). Similarly, in the subset of 115 patients (43%) in whom the culprit artery was identified, the presence of collaterals was a strong negative predictor (HR 3.71, CI 1.31-10.57, P = 0.014), driven by a 13-fold increase in subsequent CABG. CONCLUSIONS: In patients with NSTEMI the presence of angiographic coronary collaterals is a predictor of long-term clinical outcomes primarily driven by increased rates of surgical revascularization.

Impact of coronary collaterals on the outcomes of chronic total occlusion percutaneous coronary intervention.

This study aims to evaluate the impact that the presence of interventional collaterals has on the outcomes of CTO PCI. We examined the clinical and angiographic characteristics and procedural outcomes of 11 205 patients who underwent 11 444 CTO PCIs at 45 US and non-US centers between 2012 and 2023.

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.

Association of Coronary Collaterals and Myocardial Salvage Measured by Serial Cardiac Magnetic Resonance Imaging after Acute Myocardial Infarction.

BACKGROUND: Coronary collateral flow in angiography has been linked with lower mortality rates in patients with coronary artery disease. However, the relevance of the underlying mechanism is sparse. Therefore, we tested the hypothesis that in patients with acute myocardial infarction (AMI), relevant coronary collateral flow is associated with more salvaged myocardium and lower risk of developing heart failure. METHODS AND RESULTS: Patients with first AMI who received a percutaneous coronary intervention within 24 h after symptom onset were classified visually by assigning a Cohen-Rentrop Score (CRS) ranging between 0 (no collaterals) and 3 (complete retrograde filling of the occluded vessel). All 36 patients included in the analysis underwent cardiac magnetic resonance examination within 3 to 5 days after myocardial infarction and after 12 weeks. Patients with relevant collateral flow (CRS 2-3) to the infarct-related artery had significantly smaller final infarct size compared to those without (7 ± 4% vs. 20 ± 12%, p < 0.001). In addition, both groups showed improvement in left ventricular ejection fraction early after AMI, whereas the recovery was greater in CRS 2-3 (+8 ± 5% vs. +3 ± 5%, p = 0.015). CONCLUSION: In patients with first AMI, relevant collateral flow to the infarct-related artery was associated with more salvaged myocardium at 12 weeks, translating into greater improvement of systolic left ventricular function. The protective effect of coronary collaterals and the variance of infarct location should be further investigated in larger studies.

CXCL5 gene polymorphisms and coronary collateralization.

Background: The presence of coronary collateralization is heterogenous, even amongst those with similar degrees of epicardial coronary artery stenoses. We hypothesized that genetic variation of CXCL5, a chemokine that mediates angiogenesis, is associated with coronary collateralization. Methods: We genotyped subjects undergoing coronary angiography for single nucleotide polymorphisms of CXCL5 and determined the presence of spontaneously visible coronary collaterals. Results: Subjects with collaterals had less angina (46 % vs 59 %, p = 0.006), and prior percutaneous coronary intervention (34 % vs 47 %, p = 0.010), and more hyperlipidemia (90 % vs 82 %, p = 0.018), peripheral arterial disease (25 % vs 17 %, p = 0.041), congestive heart failure (16 % vs 8 %, p = 0.007), and multi-vessel coronary artery disease (41 % vs 24 %, p = 0.0001) compared to those without collaterals. Multi-vessel disease and hyperlipidemia were positive predictors of angiographically visible collaterals while being a carrier of the CXCL5 polymorphism was a negative predictor. Conclusions: Coronary collateralization may, at least in part, be genetically determined.

Do collaterals visualized on coronary angiography impact left ventricle ejection fraction among Asian Indians presenting with acute coronary syndrome? The Deucalion Study.

BACKGROUND: The coronary collaterals have been ascribed as a potential alternative source of myocardial perfusion to the extent that some suggest it as a "natural bypass"! We proposed to evaluate the impact of the extent of collaterals on left ventricle ejection fraction among Asian Indians presenting with acute coronary syndrome. METHODS: This was a retrospective, all-comers study performed on consecutive 3614 patients presenting with the acute coronary syndrome. Angiograms were evaluated for collaterals graded according to Rentrop's classification among group A (grades 0 and 1) and group B (grades 2 and 3) collaterals. RESULTS: Patients were matched for traditional cardiovascular risk factors in groups A and B as well as for ST elevation myocardial infarction and non-ST elevation myocardial infarction subgroups in both the groups. Grades 2 and 3 collaterals were significantly (P = 0.04) higher in patients with non-ST elevation myocardial infarction-266/1319 (20.17%), as compared to ST elevation myocardial infarction-group 400/2295 (17.43%). Left ventricle ejection fraction on presentation was better preserved in group A as compared to group B in those with double-vessel disease and triple-vessel disease patients with non-ST elevation myocardial infarction, whereas it was better in single-vessel disease and triple-vessel disease patients with ST elevation myocardial infarction. The inverse correlation (r = -0.111, P = 0.000) existed between left ventricle ejection fraction and grades of collaterals. CONCLUSION: Patients with the single-vessel disease were more likely to have poor coronary collateral as compared to double-vessel disease/triple-vessel disease. Despite higher grade coronary collateral among Asian Indians presenting with acute coronary syndrome, both non-ST elevation myocardial infarction and ST elevation myocardial infarction patients with triple-vessel disease had significantly lower left ventricle ejection fraction. This paradoxically brings out worse left ventricle ejection fraction on presentation in those with double-vessel disease and triple-vessel disease with ST elevation myocardial infarction and single-vessel disease and triple-vessel disease with ST elevation myocardial infarction despite higher grade of coronary collateral representing as "Asian Indian Paradox" in our cohort.

Does the extent of collaterals influence the severity of the myocardial injury as assessed by elevation in biomarkers?

Introduction: Quantitative analysis of cardiac biomarkers, troponin I and CPK-MB, estimates the extent of myocardial injury while extent of benefit from coronary collateral circulation (CCC) to protect myocardium during acute myocardial infarction (AMI) needs validation. We analysed if the extent of collaterals had impact on baseline biomarkers at the time of coronary angiogram. Methods: We analysed 3616 consecutive patients who presented with AMI and underwent invasive coronary angiography (CAG) with intent to revascularisation with biomarkers assessment at the time of CAG. CCC to Infarct related artery (IRA) were graded as per Rentrop grading viz. poorly-developed CCC (Grade 0/1 as Group A) and well-developed CCC (Grade 2/3 as Group B). Results: Both groups (A and B) were matched for demographics, traditional risk factors, SYNTAX 1 Score, time to CAG from onset of angina and eGFR. 36.59% of patients had Non-ST segment elevation myocardial infarction (NSTEMI) as compared to 63.41% ST -segment elevation infarction (STEMI). Overall Troponin I (P =0.01, P =0.01) and CPK MB (P =0.00, P =0.002) values were lower in group B in both NSTEMI and STEMI groups respectively. Troponin I and CPK-MB were significantly lower in group B [with NSTEMI for SVD (Single vessel disease) (P =0.05) and DVD (Double vessel disease) (P =0.04),but not for TVD (Triple vessel disease) and with STEMI in SVD (P =0.01), DVD (P =0.01) and TVD (P =0.001)]. Conclusion: Patients with well-developed coronary collaterals had a lower rise in biomarkers in AMI as compared to those with poor collaterals amongst both NSTEMI and STEMI groups.

Occurrence of Coronary Collaterals in Acute Myocardial Infarction and Sleep Apnea.

Background In patients with acute myocardial infarction (MI), cardioprotective effects of obstructive sleep apnea are postulated on account of hypoxemic preconditioning. The aim of this single-center substudy was to investigate a potential association between obstructive sleep apnea and the presence of coronary collaterals in patients with first-time acute MI who have been enrolled in an ongoing, multicenter clinical trial. Methods and Results In TEAM-ASV I (Treatment of Sleep Apnea Early After Myocardial Infarction With Adaptive Servo-Ventilation Trial; NCT02093377) patients with first acute MI who received a coronary angiogram within 24 hours after onset of symptoms underwent polygraphy within the first 3 days. Coronary collaterals were classified visually by assigning a Cohen-Rentrop Score (CRS) ranging between 0 (no collaterals) and 3. Of 94 analyzed patients, 14% had significant coronary collaterals with a CRS ≥2. Apnea-Hypopnea Index (AHI) score was significantly higher in patients with CRS ≥2 compared with those with CRS <2 (31/hour [11-54] versus 13/hour [4-27]; P=0.032). A multivariable regression model revealed a significant association between obstructive AHI and CRS ≥2 that was independent of age, sex, body mass index, and culprit lesion left anterior descending artery (odds ratio [OR], 1.06; 95% CI, 1.01-1.12; P=0.023), but no significant association between coronary collaterals and central AHI (OR, 1.02; 95% CI, 0.97-1.08; P=0.443). Conclusions Patients with first-time acute MI had more extensive coronary collateralization with an increased AHI or rather an increased obstructive AHI. This finding supports the hypothesis that obstructive sleep apnea exerts potential cardioprotective effects, in addition to its known deleterious effects, in patients with acute MI. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02093377.

Impact of coronary artery bypass grafting (CABG) on coronary collaterals in patients with a chronic total occlusion (CTO).

Chronic total occlusions (CTO) are found commonly in patients with prior coronary artery bypass grafting (CABG). We sought to determine the effect of CABG on collateral robustness in patients with a CTO. Patients with a CTO diagnosed on coronary angiography between July 2010 and December 2019 were included in this study. Patients were classified as either CTO supplied by a functional graft, CTO supplied by collaterals from a non-grafted donor vessel (non-grafted) or a CTO supplied by collaterals from a grafted donor vessel (grafted). The degree of collateral robustness was determined by the Rentrop classification and collateral connection (CC) grade. Demographic, angiographic and clinical outcomes were recorded. A total of 2088 CTO lesions were identified, of which 878 (42.0%) were supplied by a functional graft, 994 (47.6%) CTOs were supplied by a non-grafted donor vessel and 216 (10.3%) CTOs were supplied by a grafted donor vessel. CTOs supplied by a grafted donor vessel had lower rates of robust collaterals (37.0% vs 83.0%, p < 0.0001) with less mature collaterals as determined by the Rentrop grade (p < 0.0001) and CC grade (p < 0.0001) as compared to CTOs supplied by a non-grafted donor vessel. In patients with a previous CABG, a grafted donor vessel results in less robust coronary collaterals with lower Rentrop and CC grade compared to an ungrafted donor vessel. This may be attributable to changes in coronary blood flow and shear stress, and may be a factor in the lower procedural success rates for CTO intervention in patients with prior CABG.

Endothelial Avulsion of the Septal Branch During Retrograde Chronic Total Occlusion Intervention.

Percutaneous revascularization of chronic total occlusions (CTOs) is known for the high technical complexity. Considering the constant increase in CTO procedures, subsequent peri-procedural complications will rise too, thus they need to be promptly recognized and evaluated for their potential risk of clinical sequelae. We report the case of a newly described complication during trans-septal retrograde CTO intervention: a septal collateral artery dissection due to endothelial avulsion.