Angiographic Collateral Grade Research Articles

Predicting futile recanalization risk in acute basilar artery occlusion: Combination of collateral status and pre-procedural systemic inflammation response index

Acute basilar artery occlusion (ABAO) is a rare form of acute ischemic stroke (AIS). Endovascular treatment (EVT) has emerged as a primary therapeutic approach for achieving early reperfusion of the ischemic area. However, a favorable prognosis remains elusive for a considerable number of patient post-recanalization. The assessment of disparities in hematological and radiological indicators is of notable significance for predicting the prognosis of AIS patients. Our study aimed to predict futile recanalization (FR) by analyzing inflammation levels and collateral status in ABAO patients treated with EVT. Clinical data were collected from January 2019 to March 2023. The angiographic collateral grading system for basilar artery occlusion (ACGS-BAO) and the systemic inflammation response index (SIRI) was employed to assess the collateral status and inflammation levels, respectively. FR was defined as patients experiencing an unfavorable functional outcome (modified Rankin Scale >2) at 3-month post-EVT, despite successful recanalization (modified Thrombolysis in Cerebral Infarction 2b or 3). Logistic regression models were utilized to analyze the association of ACGS-BAO and SIRI with FR. A total of 72 (65.5%) patients developed FR. Multivariate logistic analysis revealed that ACGS-BAO (odds ratio [OR]: 0.343, 95% confidence interval [CI]: 0.179 – 0.658, P = 0.001), procedure time (OR: 1.028, 95% CI: 1.007 – 1.050, P = 0.01), and natural logarithm-transformed of the SIRI (Ln[SIRI]) (OR: 2.857, 95% CI: 1.518 – 5.380, P = 0.001) were independently associated with FR. In receiver operating characteristic analysis, the area under the curve for ACGS-BAO combined SIRI was 0.789 (95% CI: 0.699 – 0.878; P < 0.001). The effects of ACGS-BAO and Ln(SIRI) on FR were similar in all subgroups (P > 0.10 for all interactions). In conclusion, poor collateral status and high inflammatory levels are independent predictors of FR after EVT in patients with ABAO.

Automatic assessment of collaterals physiology in chronic total occlusions by means of artificial intelligence.

Assessment of collaterals physiology in chronic total occlusions (CTO) currently requires dedicated devices, adds complexity, and increases the cost of the intervention. This study sought to derive collaterals physiology from flow velocity changes (ΔV) in donor arteries, calculated with artificial intelligence- aided angiography. Angiographies with successful percutaneous coronary intervention (PCI) in 2 centers were retro- spectively analyzed. CTO collaterals were angiographically evaluated according to Rentrop and collateral connections (CC) classifications. Flow velocities in the primary and secondary collateral donor arteries (PCDA, SCDA) were automatically computed pre and post PCI, based on a novel deep-learning model to extract the length/time curve of the coronary filling in angiography. Parameters of collaterals physiology, Δcollateral-flow (Δfcoll) and Δcollateral-flow-index (ΔCFI), were derived from the ΔV pre-post. The analysis was feasible in 105 out of 130 patients. Flow velocity in the PCDA significantly decreased after CTO-PCI, proportionally to the angiographic collateral grading (Rentrop 1: 0.02 ± 0.01 m/s; Rentrop 2: 0.04 ± 0.01 m/s; Rentrop 3: 0.07 ± 0.02 m/s; p < 0.001; CC0: 0.01 ± 0.01 m/s; CC1: 0.04 ± ± 0.02 m/s; CC2: 0.06 ± 0.02 m/s; p < 0.001). Δfcoll and ΔCFI paralleled ΔV. SCDA also showed a greater reduction in flow velocity if its collateral channels were CC1 vs. CC0 (0.03 ± 0.01 vs. 0.01 ± 0.01 m/s; p < 0.001). For each individual patient, ΔV was more pronounced in the PCDA than in the SCDA. Automatic assessment of collaterals physiology in CTO is feasible, based on a deeplearning model analyzing the filling of the donor vessels in angiography. The changes in collateral flow with this novel method are quantitatively proportional to the angiographic grading of the collaterals.

Original Article--Value of Pathological Q Waves and Angiographic Collateral Grade in Patients Undergoing Coronary Chronic Total Occlusion Recanalization: Cardiac Magnetic Resonance Study.

Background/aimSuccessful coronary chronic total occlusion (CTO) revascularization was found by many studies to be associated with improved left ventricular (LV) systolic function and survival if evidence of viability is present. Little is known about the association of CTO revascularization in patients with electrocardiographic Q waves and improvement in angina burden as a measurement of health-related quality of life (HRQOL) afterwards.MethodsIn this study, 100 patients with single vessel CTO were included. Myocardial viability was tested by late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) and 50 patients showed evidence of viability. Seattle Angina Questionnaire (SAQ) scores were used as a measure of HRQOL.ResultsPathological Q waves were present in 48 patients (including 19 patients with viable CTO territory) out of 100 patients. Patients with Q waves tended to have worse Seattle Angina Questionnaire (SAQ) scores compared to those with no Q waves (31.2 ± 11.7 vs 45.3 ± 13.9 respectively, p = 0.002), worse LV systolic function and wall motion score index (WMSI) on CMR. They also had significantly less prevalence of viability (p < 0.001). Patients with Q waves and positive viability had lower SAQ scores (37.2 ± 10.1 vs 52.7 ± 13.2 respectively, p = 0.02), higher LVEF and lower WMSI. They also had well developed collateral grade (2.1 ± 1.03 vs 0.7 ± 0.82 respectively, p < 0.001). After successful percutaneous coronary intervention (PCI), in the viable LV group, presence of Q waves was not associated with better LV functional recovery, while those with higher collateral grades were more likely to have better LV functional recovery post CTO-PCI. Patients with Q waves and viable CTO territory showed significantly better SAQ scores compared to pre-PCI (87.3 ± 12.2 vs 37.2 ± 10.1 respectively, p < 0.001). For angina frequency, post–PCI score was 80.2 ± 7.9 compared to 39.2 ± 7.1 before PCI, p < 0.001). Multivariate regression analysis showed that pathological Q waves, Rentrop's collateral grade and the Canadian Cardiovascular Society (CCS) angina class before PCI were the most significant independent predictors of improved HRQOL as reflected by SAQ (OR for Q waves 7.83, 95% CI 1.62–18.91,p 0.003), (OR for Rentrop's collateral grade 8.31,95% CI 2.21–26.33, p < 0.001), (OR for CCS class 8.39, 95% CI 1.21–20.8, p 0.01).ConclusionWell-developed collateral circulation could independently predict LV functional recovery after CTO-PCI. Patients with Q waves and viable CTO territory tend to have higher CCS class before revascularization and get significant improvement of HRQOL after PCI. Other predictors of improved HRQOL are Rentrop's collateral grade and worse CCS class before PCI.

A New Angiographic Collateral Grading System for Acute Basilar Artery Occlusion Treated with Endovascular Therapy.

Poor clinical outcomes despite endovascular therapy (EVT) are common in patients with acute basilar artery occlusion (BAO). We aimed to develop a new angiographic collateral grading system for predicting 90-day functional outcomes of acute BAO after EVT. A prospectively registered consecutive cohort of acute BAO patients treated with EVT in our center during a 6-year period was reviewed. The angiographic collateral grading system for BAO (ACGS-BAO) included 4 grades for poor (grade 1-2), intermediate (grade 3), and good (grade 4) collateral statuses. First, the independent association of ACGS-BAO with 90-day functional independence (mRS ≤ 2), favorable outcome (mRS ≤ 3), and death was evaluated by multivariable logistic regression model; then, the heterogeneity in the effects of ACGS-BAO on 90-day outcomes was explored among the subgroups stratified by age, time window, stroke severity, and etiology. Finally, the interobserver agreement of ACGS-BAO was assessed by weighted kappa statistic. Of 173 patients included in this study, 62 (35.8%), 83 (48.0%), and 36 (20.8%) achieved 90-day functional independence, favorable outcome, and death, respectively. Multivariable logistic analyses showed that ACGS-BAO was independently associated with functional independence (OR = 2.07, 95% CI = 1.05-4.07) and favorable outcome (OR = 1.84, 95% CI = 1.02-3.43) but not related to death (OR = 0.78, 95% CI = 0.37-1.64). Similar effects of ACGS-BAO on 90-day outcomes were seen across all subgroups (P > 0.10 for all interactions). The interobserver agreement of ACGS-BAO was very high (weighted kappa = 0.96, 95% CI = 0.93-0.99). The ACGS-BAO is an angiographic tool with excellent interobserver reliability that can be used to predict the 90-day outcome of acute BAO treated by EVT. Nevertheless, our findings are still needed to be confirmed in a prospective multicenter study before clinical application.

Abstract 200: Collaterals in SWIFT PRIME: Imaging Correlates and Ultimate Impact

Background: The overwhelming benefit of endovascular stroke therapy established in recent trials fueled by rapid workflow, modern devices and favorable noninvasive imaging profiles newly question the impact of collateral grade. We analyzed the SWIFT PRIME trial to evaluate the role of collaterals with respect to advanced imaging selection, the pace of infarct growth and ultimate clinical outcomes. Methods: Conventional angiography of the endovascular arm in SWIFT PRIME (n=98) was reviewed by 3 independent readers that scored ASITN/SIR collateral flow grade, followed by consensus adjudications. Angiographic collaterals were scored only when available, prior to use of the Solitaire stent retriever. Statistical analyses investigated the relationship of collateral grade with clinical and imaging variables in the main trial dataset. Results: 70 endovascular arm subjects (mean age 65.2±12.1 years, 35 (50%) women) had angiographic collaterals scored by 3 independent readers ( W =0.93). Pretreatment CT or MR perfusion imaging was obtained in 92% of cases, associated with a relatively wide range of angiographic collateral grades (1, n=6 (9%); 2, n=25 (36%); 3, n=37 (53%); 4, n=2 (3%)) with a preponderance (79%) of M1 occlusions. Worse collaterals were associated with prior myocardial infarction (33% (grade 1), 8% (grade 2), 3% (grades 3, 4); p=0.03) but unrelated to age, sex, or other co-morbidities or time from stroke onset. Baseline ASPECTS (median 9, r=0.20) trended higher (p=0.09) in those with more robust collaterals. Collaterals were unrelated to degree of TICI reperfusion, yet the presence of distal emboli at procedure end was linked with worse collaterals (p=0.008). More robust collaterals exhibited a potent and graded link with better day 90 mRS (r=- 0.3, p=0.03) and lower mean NIHSS at 27 hours (r=-0.3, p=0.03), whereas infarct growth at 27 hours was unrelated (r=-0.07, p=0.60). Conclusions: Use of advanced noninvasive perfusion imaging enrolls patients with more robust collateral grades, yet a diverse range of collaterals may be seen. Even with rapid workflow, mismatch based selection and successful reperfusion, the degree of angiographic collaterals continues to be strongly associated with clinical outcomes at all timepoints.

Impact of time-to-reperfusion on outcome in patients with poor collaterals.

The relationship between reperfusion and clinical outcome is time-dependent, and the effect of reperfusion on outcome can vary on the basis of the extent of collateral flow. We aimed to identify the impact of time-to-reperfusion on outcome relative to baseline angiographic collateral grade in patients successfully treated with endovascular revascularization for acute large-vessel anterior circulation stroke. Two hundred seven patients were selected for analysis from our prospectively maintained registry. Inclusion criteria were M1 MCA ± ICA occlusions, onset-to-puncture time within 8 hours, and successful endovascular reperfusion. Baseline angiographic collateral grades were independently evaluated and dichotomized into poor (0-1) versus good (2-4). Multivariable analyses were performed to identify the effect of collateral-flow adequacy on favorable outcome on the basis of onset-to-reperfusion time and puncture-to-reperfusion time. In the poor collateral group, the odds of favorable outcome significantly dropped for patients with onset-to-reperfusion time of >300 minutes or puncture-to-reperfusion time of >60 minutes (onset-to-puncture time: ≤300, 59% versus >300, 32%; OR, 0.24; P = .011; puncture-to-reperfusion time: ≤60, 73% versus >60, 32%; OR, 0.21, P = .011), whereas the probability of favorable outcome in the good collateral group was not significantly influenced by onset-to-reperfusion time or puncture-to-reperfusion time. In the subgroup lesion-volume growth analysis by using DWI, the effect of puncture-to-reperfusion time of >60 minutes was significantly greater compared with the effect of puncture-to-reperfusion time of <60 minutes in the poor collateral group (β = 41.6 cm(3), P = .001). Time-to-reperfusion including onset-to-reperfusion time and puncture-to-reperfusion time in patients with poor collaterals is an important limiting factor for favorable outcome in a time-dependent fashion. Future trials may benefit from a noninvasive imaging technique to detect poor collaterals along with a strategy for rapid reperfusion.

Usefulness of the parameters of quantitative myocardial perfusion contrast echocardiography in patients with chronic total occlusion and collateral flow.

Microvascular obstruction becomes more severe with longer duration of ischemia, such as chronic total occlusion (CTO) which used to have collateral flow. In this study, we explored the correlation between parameters measured using quantitative myocardial perfusion contrast echocardiography (MCE) and the angiographic collateral flow grades in patients with CTO. Furthermore, we investigated the usefulness of the parameters of quantitative MCE for the measurement of microvasculature changes after revascularization of CTO lesions. Between January 2011 and January 2013, 44 patients who had undergone coronary angiography (CAG) due to chest pain and had confirmed CTO lesions were enrolled in this prospective observational study. All patients had baseline MCE within 24 hours after diagnostic CAG. Patients were then assigned to one of two groups: a medical therapy group (Group I, n = 20) or a reperfusion group with percutaneous coronary intervention (PCI) (Group II, n = 24). All patients had follow-up MCE 3 months later. Consistent with the CAG results in both groups, on baseline MCE, the myocardial blood flow (AI × β) values were higher in Grade III collateral flow than in Grade I or II collateral flow (AI of collateral flow Grade I vs. Grade II vs. Grade III: 2.34 ± 2.65 vs. 2.52 ± 2.67 vs. 3.87 ± 4.57, P = 0.038). The plateau acoustic intensity (AI) and wall-motion score index (WMSI) were significantly improved at the 3-month follow-up after successful reperfusion with PCI (5.75 ± 3.52 before vs. 8.11 ± 6.02 after, P = 0.004) and (1.76 ± 0.83 before vs. 1.43 ± 0.64 after, P ≤ 0.001), respectively. However, the AI and WMSI values were not improved in the medical treatment group, (6.04 ± 4.64 before vs. 6.01 ± 5.52 after, P = 0.966) and (1.61 ± 0.82 before vs. 1.66 ± 0.67 after, P = 0.616), respectively. MCE is a useful tool for estimating microvascularity in patients with CTO lesions and correlates well with angiographic collateral flow.

Chronic Total Artery Occlusions in Noninfarct-Related Coronary Arteries

It has been rarely encountered some patients in clinical practice with coronary artery chronic total occlusion (CTO) on angiography but no any clinical history or electrocardiographic, echocardiographic, or left ventriculographic evidence of previous myocardial infarction. These noninfarct-related artery CTO (non-IRA CTO) lesions may be used as a clinical role model of endogenous cardioprotective mechanisms in addition to continuing the process of atherosclerosis. The objective of this study was to characterize the clinical characteristics of patients with non-IRA CTO patients and compared them to those with infarct-related CTO (IRA-CTO). We reviewed our invasive cardiology database searching for the CTO of any major coronary arteries, and assessed whether or not they have the clinical history or electrocardiographic, echocardiographic, and left ventriculographic evidence of previous myocardial infarction. Interestingly, we detected that all these patients with non-IRA CTO had diabetes mellitus, and the clinical and demographic features of these non-IRA CTO patients were compared with age- and sex-matched diabetic IRA-CTO patients with regard to conventional coronary risk factors and the angiographic collateral grading system. There were total 99 CTO patients (49 patients with non-IRA CTO and 50 patients with IRA-CTO).All patients with non-IRA CTO had better collateral circulation (96 vs. 40% p < 0.001) compared with those having IRA-CTO. The only significant difference between the groups was the status of current smoking (4 vs. 88%; p < 0.001). The present study showed that the non-IRA CTOs were associated with diabetes mellitus and better collateral development compared with IRA-CTO. In diabetic patients, the concomitant smoking use may be harmful by preventing endogenous cardioprotective mechanisms.

Collaterals at Angiography and Outcomes in the Interventional Management of Stroke (IMS) III Trial

Endovascular strategies provide unique opportunity to correlate angiographic measures of collateral circulation at the time of endovascular therapy. We conducted systematic analyses of collaterals at conventional angiography on recanalization, reperfusion, and clinical outcomes in the endovascular treatment arm of the Interventional Management of Stroke (IMS) III trial. Prospective evaluation of angiographic collaterals was conducted via central review of subjects treated with endovascular therapy in IMS III (n=331). Collateral grade before endovascular therapy was assessed with the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology scale, blinded to all other data. Statistical analyses investigated the association between collaterals with baseline clinical variables, angiographic measures of recanalization, reperfusion and clinical outcomes. Adequate views of collateral circulation to the ischemic territory were available in 276 of 331 (83%) subjects. Collateral grade was strongly related to both recanalization of the occluded arterial segment (P=0.0016) and downstream reperfusion (P<0.0001). Multivariable analyses confirmed that robust angiographic collateral grade was a significant predictor of good clinical outcome (modified Rankin Scale score≤2) at 90 days (P=0.0353), adjusted for age, history of diabetes mellitus, National Institutes of Health Stroke Scale strata, and Alberta Stroke Program Early CT Score. The relationship between collateral flow and clinical outcome may depend on the degree of reperfusion. More robust collateral grade was associated with better recanalization, reperfusion, and subsequent better clinical outcomes. These data, from the largest endovascular trial to date, suggest that collaterals are an important consideration in future trial design. http://www.clinicaltrials.gov. Unique identifier: NCT00359424.

Role of Statin in Atrial Fibrillation-Related Stroke: An Angiographic Study for Collateral Flow

Background: Currently, intensive lipid lowering is recommended in patients with atherosclerotic ischemic stroke or transient ischemic attack. However, the role of statin in cardioembolic stroke is unclear. We investigated the association of statin with pretreatment collateral status in cardioembolic stroke. Methods: A collaborative study from two stroke centers in distinct geographic regions included consecutive patients with acute middle cerebral artery (MCA) infarction due to atrial fibrillation (AF) who underwent cerebral angiography. The relationship between pretreatment collateral grade and the use/dose of statin at stroke onset was assessed. The angiographic collateral grade was evaluated according to the ASITN/SIR Collateral Flow Grading System. Results: Ninety-eight patients (76 statin-naïve, 22 statin users) were included. Compared with statin-naïve patients, statin users were older and more frequently had hypertension, hyperlipidemia and coronary heart disease. Excellent collaterals (grade 3-4) were more frequently observed in statin users (11 patients, 50%) than in statin-naïve patients (21 patients, 27.6%; p = 0.049). The use of atorvastatin 10 mg equivalent or higher doses of statin was associated with excellent collaterals (p for trend = 0.025). In multiple regression analysis, prestroke statin use was independently associated with excellent collaterals (odds ratio, 7.841; 95% confidence interval, CI, 1.96-31.363; p = 0.004). Conclusions: Premorbid use of statin in AF patients is associated with excellent collateral flow. Although most statin trials excluded patients with cardioembolic stroke, our data suggests the possibility that statin may be beneficial in AF-related stroke.

The combination of baseline magnetic resonance perfusion-weighted imaging-derived tissue volume with severely prolonged arterial-tissue delay and diffusion-weighted imaging lesion volume is predictive of MCA-M1 recanalization in patients treated with endovascular thrombectomy

IntroductionIndices of collateral flow deficit derived from MR perfusion imaging that are predictive of MCA-M1 recanalization after intravenous thrombolysis have been recently reported. Our objective was to test the performance of such MRI-derived collateral flow indices for prediction of recanalization after endovascular thrombectomy.MethodsFifty-seven patients with MCA-M1 occlusion evaluated with multimodal MRI prior to thrombectomy were included. Bayesian processing allowed quantification of collateral perfusion indices like the volume of tissue with severely prolonged arterial-tissue delay (>6 s) (VolATD6). Baseline DWI lesion volume was also measured. Correlations with angiographic collateral flow grading and post-thrombectomy recanalization were assessed.ResultsVolATD6 < 27 ml or DWI lesion volume <15 ml provide the most accurate diagnosis of excellent collateral supply (p < 0.0001). The combination of VolATD6 > 27 ml and DWI lesion volume >15 ml significantly discriminates recanalizers versus nonrecanalizers (whole cohort, p = 0.032; MERCI cohort (n = 50), p = 0.024). When both criteria are positive, 76.2 % of the patients treated with the MERCI retriever do not fully recanalize (p = 0.024). In multivariate analysis, the aforementioned combined criterion and the angiographic collateral grade are the only independent predictors of recanalization with the MERCI retriever (p = 0.015 and 0.029, respectively).ConclusionBayesian arterial-tissue delay maps and DWI maps provide a non-invasive assessment of the degree of collateral flow and a combined index that is predictive of MCA-M1 recanalization after endovascular thrombectomy. Further studies are needed to evaluate the accuracy of this index in patients treated with novel stent retriever devices.

Impacto clínico da isquemia e viabilidade miocárdicas após tratamento de oclusão coronária crônica no segmento proximal da artéria descendente anterior

INTRODUÇÃO: A avaliação da isquemia e viabilidade miocárdicas é recomendável antes da intervenção coronária percutânea (ICP) em oclusões crônicas. Avaliamos os eventos cardiovasculares adversos tardios de pacientes com ICP da oclusão crônica no segmento proximal da artéria descendente anterior, comparando pacientes de acordo com a presença ou não de isquemia ou viabilidade miocárdicas. MÉTODOS: Os pacientes foram alocados nos grupos com isquemia/viabilidade miocárdicas (G1, n = 91) e sem isquemia/viabilidade miocárdicas (G2, n = 65) e avaliados os eventos clínicos combinados tardios (óbito, infarto do miocárdio, revascularização do vaso-alvo e insuficiência cardíaca congestiva). RESULTADOS: A maioria dos pacientes era do sexo masculino (68,1% vs. 69,2%; P = 0,56), com média de idade de 65,4 ± 10,4 anos vs. 63,5 ± 8,7 anos (P = 0,61), e quase um terço era de diabéticos (33% vs. 29,2%; P = 0,76). Os grupos não mostraram diferenças em relação ao perfil clínico-angiográfico, com exceção da fração de ejeção do ventrículo esquerdo (48,6 ± 13,7% vs. 39,5 ± 11,8%; P = 0,04) e do grau de circulação colateral para a artéria descendente anterior, mais evidente no G1 (P = 0,03). A incidência de eventos clínicos combinados em um período de três anos foi menor nos pacientes com isquemia/viabilidade miocárdicas (12,5% vs. 31,1%; P < 0,01). Os fatores que mais contribuíram para essa diferença foram a incidência de insuficiência cardíaca congestiva (3,3% vs. 15,3%; P = 0,02) e óbito (2,2% vs. 7,7%; P = 0,13). CONCLUSÕES: O tratamento de oclusão crônica no segmento proximal da artéria descendente anterior com stent farmacológico, em pacientes com evidência de isquemia ou viabilidade miocárdicas, reduz eventos clínicos a longo prazo.

Abstract WP40: “Good” Angiographic Collateral Circulation Correlates With Lower Dwi Infarct Volumes In Acute Ischemic Stroke

Background and purpose Large artery occlusion leads to ischemic stroke which volume is influenced by time from symptom onset. This effect is modulated by several factors, including the presence and degree of collateral circulation. We analyze the correlation between a standard angiographic collateral grading system and DWI infarct volumes. Methods We reviewed a prospectively collected retrospective database of ischemic stroke patients admitted between august of 2006 and december of 2011. We included patients with anterior circulation acute ischemic stroke presenting within 8 hours from symptom onset with large vessel occlusion, who underwent pre-treatment MRI and endovascular therapy. DWI infarct volumes were measured by region of interest. ASITN collateral grading system was used and grouped into “good collaterals” for grades 3 and 4, and “poor collaterals” for grades 0, 1 and 2. JMP statistical software was utilized. Results 152 patients (71 (46.7%) male, mean age: 68±15 years;) were included in the initial analysis. We identified 49 patients who had angiographic collateral circulation grading. Seven patients had ASITN collateral grade 0 with mean infarct volume of 27.6 cc, 25 had collateral grade of 1 with mean infarct volume of 27.9 cc, 10 had collateral grade of 2 with mean infarct volume of 23.4 cc, 5 had collateral grade of 3 with mean infarct volume of 6.3 cc, and 2 had collateral grade of 4 with mean infarct volume of 14.6 cc. Forty two patients had “poor collaterals” with a mean infarct volume of 26.8 cc. Seven patients had “good collaterals” with mean infarct volume of 8.7 cc. When comparing the infarct volumes between these two groups, the difference was statistically significant (p=0.017). Conclusions In anterior circulation acute ischemic stroke, “good” angiographic collateral circulation defined as ASITN grading system of 3 or 4, correlates with lower infarct volumes on presentation.

Abstract 57: Impact of Collaterals on Successful Revascularization in SWIFT

Background: Collaterals are a potential determinant of recanalization and tissue fate after endovascular therapy. We analyzed angiographic collateral grade to ascertain impact on the novel endpoint of successful revascularization without symptomatic hemorrhage, a “metric of unqualified success” in the SWIFT trial. Methods: Collateral grade was independently assessed with the ASITN/SIR scale on baseline angiography, blind to core lab and other data. Univariate and multivariate regression analyses detailed the relationship of collateral grade with clinical, laboratory and imaging parameters. Results: Angiographic data on collaterals were available in 119/144 subjects (mean age 67±12 years, 52% female, median NIHSS 18 (range 8-28)). Collateral grade was 0-1 (none or marginal) in 32 (27%), 2 (partial) in 48 (40%), 3 (complete but delayed) in 35 (29%), and 4 (complete and early) in 4 (3%). Collateral vigor was unrelated to age or gender. Elevated baseline blood glucose was noted with worse collaterals (0-1 - mean 154±65 mg/dL; 2 - 140±75; 3 - 124±33; 4 - 99±10; p=0.013). Elevated baseline systolic BP was also associated with worse collaterals (0-1 - mean 149±24 mm Hg; 2 - 137±23; 3 - 137±24; 4 - 138±10; p=0.039). Multivariate predictors of partial or worse collaterals included absence of prior hypertension (OR 4.049, p=0.012), smoking history (OR 3.822, p=0.013) and higher blood glucose (OR 1.017, p=0.022). Collaterals were strongly related to ASPECTS at baseline (0-1 - median 8 (3-10); 2 - 9 (5-10); 3 - 9 (7-10); 4 - 9 (8-10); p&lt;0.001) and 24 hours (0-1 - median 1 (0-5); 2 - 6 (0-10); 3 - 8 (0-10); 4 - 8 (4-8); p&lt;0.001). Partial or worse collaterals were associated with symptomatic hemorrhage (p=0.075). Better collaterals were linked with TICI 2b/3 reperfusion (p=0.019), better median NIHSS at Day 7/discharge (p&lt;0.001) and better Day 90 mRS (p&lt;0.001). Better collaterals were noted in patients with successful revascularization without symptomatic hemorrhage, mean 2.3 (95% CI 2.1-2.5) vs. 1.9 (95% CI 1.7-2.2), p=0.021. Conclusions: Collateral rigor was associated with lower glucose, lower BP, and smaller baseline infarcts in SWIFT. Better collaterals predicted greater likelihood of successful revascularization without hemorrhage and better clinical outcomes.

Clinical impact of myocardial ischemia and viability after treatment of proximal left anterior descending artery chronic total occlusions

ABSTRACT Background Evaluation of myocardial ischemia and viability is recommended prior to percutaneous coronary intervention (PCI) for chronic total occlusions. We evaluated late adverse cardiovascular events of patients with PCI for proximal left anterior descending artery occlusions, comparing patients with or without myocardial ischemia or viability. Methods Patients were allocated to groups with myocardial ischemia/ viability (G1, n = 91) and without myocardial ischemia/ viability (G2, n = 65) and adverse cardiovascular events (death, myocardial infarction, target-vessel revascularization and congestive heart failure) were compared. Results Most patients were male (68.1% vs 69.2%; P = 0.56), with a mean age of 65.4 ± 10 years vs 63.5 ± 8.7 years (P = 0.61) and almost one third were diabetics (33% vs 29.2%; P = 0.76). No differences regarding the clinical and angiographic profile were observed, except for the left ventricular ejection fraction (48.6 ± 13.7% vs 39.5 ± 11.8%; P = 0.04) and the degree of angiographic collateral flow grade to the left anterior descending artery, which was more evident in G1 (P = 0.03). The 3-year follow-up incidence of composite adverse cardiovascular events was lower in patients with myocardial ischemia/viability (12.5% vs 31.1%; P Conclusions Treatment of proximal left anterior descending artery chronic total occlusions in patients with evidence of myocardial ischemia or viability reduces the incidence of adverse cardiovascular events in the long term.

Admission hyperglycemia causes infarct volume expansion in patients with ICA or MCA occlusion: association of collateral grade on conventional angiography

Hyperglycemia (HG) is associated with infarct volume expansion in acute ischaemic stroke patients. However, collateral circulation can sustain the ischaemic penumbra and limit the growth of infarct volume. The aim of this study was to determine whether the association between HG and infarct volume expansion is dependent on collateral circulation. We performed a retrospective analysis of 93 acute ischaemic stroke patients with internal carotid artery or middle cerebral artery occlusion within 24h of onset were retrospectively studied. HG was diagnosed in patients with an admitting blood glucose value ≥140mg/dl. Angiographic collateral grade 0-1 was designated as poor collateral circulation and grade 2-4 as good collateral circulation. Infarct volume was measured at admission and at again within 7days using diffusion-weighted magnetic resonance images. Among 34 patients with poor collateral grade, the change in infarct volume was significantly greater in the HG group than in the non-HG group (106.0ml vs. 22.7ml, P=0.002). Among the 59 patients with good collateral circulation, the change in infarct volume was greater in the HG group than in the non-HG group (53.3ml vs. 10.9ml, P=0.047). Multiple regression analysis indicated that admission HG (P=0.004), baseline National Institutes of Health Stroke Scale score (P=0.018), and poor collateral circulation (P=0.040) were independently associated with infarct volume expansion. Infarct volume expansion was greater in individuals with HG on admission regardless of collateral circulation status.

Abstract 76: Collateral Circulation in Endovascular Therapy for Acute Ischemic Stroke: Smaller Strokes, Improved Reperfusion, Less Hemorrhagic Transformation and Better Outcomes

Background: Collateral circulation moderates the impact of acute cerebral occlusion and may influence outcome from recanalization treatment. Noninvasive angiography provides some information on collateral status, but catheter angiography prior to endovascular therapy remains a unique opportunity to verify collateral grade. We conducted a comprehensive study of collaterals in acute anterior circulation occlusion to substantiate previous associations with collaterals and their impact on endovascular stroke therapy. Methods: Consecutive patients undergoing endovascular therapy for acute ischemic stroke due to anterior circulation occlusion were analyzed with respect to collaterals. Collateral grade was assessed with the ASITN/SIR scale on baseline angiography. Univariate and multivariate regression analyses detailed the relationship of collateral grade with clinical, laboratory and imaging parameters. Results: Among 113 patients, mean age was 66.9±17 years, 61.9% were female, and pretreatment NIHSS was median 17 (range 2-38). The proportion of patients in each collateral grade was: 0 - 3.5% 1 - 13.3 %; 2 - 38.9%; 3 - 31%; 4 - 13.3%. Age and gender were not associated with the degree of collateral circulation. Among medical history and laboratory variables, on multivariate ordinal regression, the sole predictor of more robust collaterals was current statin use (b 1.413, p=0.020) and predictors of worse collaterals were history of hyperlipidemia (b -1.872, p=0.001), White population (b -1.361, p=0.007) and higher WBC (b -0.306, p=0.044). More extensive collaterals correlated with smaller baseline DWI lesion volume (b 0.025, p=0.001). Interestingly, angiographic collateral grade did not correlate with PWI lesion volumes for Tmax thresholds at 2, 4, 6, or 8 seconds. More robust collaterals were associated with higher TICI reperfusion rates (ρ 0.191, p=0.043), and lower hemorrhagic transformation rates (ρ -0.229, p=0.015). mRS at discharge inversely correlated with collateral grade (ρ -0.317, p=0.001). Conclusions: The extent of collateral circulation prior to endovascular therapy exhibits a striking impact on achievement of reperfusion, tissue fate and functional outcome. Further research is needed to delineate mechanisms linking statins with better collaterals and biomarkers, such as elevated WBC, for arteriogenesis when collaterals are insufficient.

Collateral Flow Predicts Response to Endovascular Therapy for Acute Ischemic Stroke

Collaterals sustain the penumbra before recanalization and offset infarct growth, yet the influence of baseline collateral flow on recanalization after endovascular therapy remains relatively unexplored. We analyzed consecutive patients who received endovascular therapy for acute cerebral ischemia from 2 distinct study populations. We assessed the relationship between pretreatment collateral grade and vascular recanalization (Thrombolysis In Myocardial Ischemia [TIMI] scale). In addition, we assessed infarct growth on serial MRI. A total of 222 patients was included, 138 from the United States and 84 from South Korea. Complete revascularization occurred in 14.1% (11 of 78) patients with poor pretreatment collateral grades, whereas it was observed in 25.2% (26 of 103) patients with good collaterals and 41.5% (17 of 41) patients with excellent collaterals (P<0.001). This relationship was consistently observed in both study populations, although the mode of endovascular therapy was different between them. After adjustment for other factors, including mode of endovascular therapy, prior use of intravenous tissue plasminogen activator, and site of occlusion, pretreatment collateral grade was independently associated with recanalization. When revascularization was achieved, greater infarct growth occurred in patients with poor collaterals than in those with good collaterals (P=0.012). Our data indicate that angiographic collateral grade determines the recanalization rate after endovascular revascularization therapy. When therapeutic revascularization was achieved, beneficial effects were not observed in patients with poor collaterals. Angiographic collateral grade may therefore help guide treatment decision-making in acute cerebral ischemia.

Impact of Collateral Flow to the Occluded Infarct-Related Artery on Clinical Outcomes in Patients With Recent Myocardial Infarction: A Report From the Randomized Occluded Artery Trial

Collateral flow to the infarct artery territory after acute myocardial infarction may be associated with improved clinical outcomes and may also impact the benefit of subsequent recanalization of an occluded infarct-related artery. To understand the association between baseline collateral flow to the infarct territory on clinical outcomes and its interaction with percutaneous coronary intervention of an occluded infarct artery, long-term outcomes in 2173 patients with total occlusion of the infarct artery 3 to 28 days after myocardial infarction from the randomized Occluded Artery Trial were analyzed according to angiographic collaterals documented at study entry. There were important differences in baseline clinical and angiographic characteristics as a function of collateral grade, with generally lower-risk characteristics associated with higher collateral grade. Higher collateral grade was associated with lower rates of death (P=0.009), class III and IV heart failure (P<0.0001) or either (P=0.0002) but had no association with the risk of reinfarction. However, by multivariate analysis, collateral flow was neither an independent predictor of death nor of the primary end point of the trial (composite of death, reinfarction, or class IV heart failure). There was no interaction between angiographic collateral grade and the results of randomized treatment assignment (percutaneous coronary intervention or medical therapy alone) on clinical outcomes. In recent myocardial infarction, angiographic collaterals to the occluded infarct artery are correlates but not independent predictors of major clinical outcomes. Late recanalization of the infarct artery in addition to medical therapy shows no benefit compared with medical therapy alone, regardless of the presence or absence of collaterals. Therefore, revascularization decisions in patients with recent myocardial infarction should not be based on the presence or grade of angiographic collaterals. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00004562.

Collateral pressure and flow in acute myocardial infarction with total coronary occlusion correlate with angiographic collateral grade and creatine kinase levels

The validity of angiographic collateral grade according to the Rentrop classification during acute myocardial infarction (AMI) and its relation to flow in occluded coronary arteries before angioplasty have never been evaluated. We assessed the validity of the angiographic collateral grade according to Rentrop classification in relation to collateral pressure and flow beyond occluded coronary arteries during AMI. Pressure distal to coronary artery occlusions before balloon dilatation was measured in 111 patients undergoing angioplasty for AMI. We calculated the collateral flow index (CFI) and compared it to observed Rentrop grade and measured creatine kinase sum. The values of pressure distal to coronary artery occlusions with respect to collateral grades 0 to 3 were 33 +/- 12, 37 +/- 13, 42 +/- 10, and 60 +/- 14 mm Hg (P < .0001). Overall CFI was 0.35 +/- 0.13 (median 0.33), with CFI values of 0.3 +/- 0.13, 0.33 +/- 0.13, 0.39 +/- 0.1, and 0.57 +/- 0.2 for collateral grades 0 to 3, respectively (P < .0001). Larger creatine kinase elevation (P < .016) and higher white blood cell count (P < .022) were recorded in the lowest tertile CFI compared with highest tertile CFI group; but no difference in the global, regional, or infarct-related regional left ventricular contraction was found. These observations demonstrate that the Rentrop classification is valid in AMI patients with occluded coronary arteries and that collaterals are recruited acutely. These collaterals, whose pressure-derived CFI during AMI was shown for the first time to be higher than its value reported in chronic conditions, may limit the immediate myocardial damage or the systemic inflammatory response. No impact on global or regional cardiac contraction was detected in a population where most patients were treated early.