Tissue Level Perfusion Research Articles

Association Between Hypoperfusion Intensity Ratio and Postthrombectomy Malignant Brain Edema for Acute Ischemic Stroke.

Malignant brain edema (MBE) is a life-threatening complication that can occur after mechanical thrombectomy (MT) for acute ischemic stroke. The hypoperfusion intensity ratio (HIR) reflects the tissue-level perfusion status within the ischemic territory. This study investigated the association between HIR and MBE occurrence after MT in patients with anterior circulation large artery occlusion. We conducted a retrospective cohort study of patients who received MT at a comprehensive stroke center from February 2020 to June 2022. Using computed tomography perfusion, the HIR was derived from the ratio of tissue volume with a time to maximum (Tmax) > 10s to that with a Tmax > 6s. We dichotomized patients based on the occurrence of MBE following MT. The primary outcome, assessed using a multivariable logistic regression model, was the MBE occurrence post MT. The secondary outcome focused on favorable outcomes, defined as achieving a modified Rankin Scale score of 0-2 at 90days. Of the 603 included patients, 90 (14.9%) developed MBE after MT. The median HIR exhibited a significantly higher value in the MBE group compared with the non-MBE group (0.5 vs. 0.3; P < 0.001). Multivariable logistic regression analysis indicated that a higher HIR (adjusted odds ratio [aOR] 8.98; 95% confidence interval [CI] 2.85-28.25; P < 0.001), baseline large infarction (Alberta Stroke Program Early Computed Tomography Score < 6; aOR 1.77; 95% CI 1.04-3.01; P = 0.035), internal carotid artery occlusion (aOR 1.80; 95% CI 1.07-3.01; P = 0.028), and unsuccessful recanalization (aOR 8.45; 95% CI 4.75-15.03; P < 0.001) were independently associated with MBE post MT. Among those with successful recanalization, a higher HIR (P = 0.017) and baseline large infarction (P = 0.032) remained as predictors of MBE occurrence. Furthermore, a higher HIR (P = 0.001) and the occurrence of MBE (P < 0.001) both correlated with reduced odds of achieving favorable outcomes. The presence of a higher HIR on pretreatment perfusion imaging serves as a robust predictor for MBE occurrence after MT, irrespective of successful recanalization.

Abstract Number ‐ 46: Automated Magnetic Resonance Perfusion Imaging in the Management of Delayed Cerebral Ischemia: A Pilot Study

Introduction Inadequate perfusion secondary to changes in vascular narrowing and breakdown of cerebral autoregulation is thought to be a major contributor to delayed cerebral ischemia (DCI). Subjective evaluation of narrowing of large and medium intracranial vessels on angiography detects vasospasm in up to 70% of patients, though only 30% become clinically symptomatic. There are no available tools for the quantification of tissue level perfusion to detect critical levels of ischemia in this setting. We aimed to evaluate focal perfusion changes using MR‐perfusion weighted imaging with automated thresholding of flow and timing parameters in the setting of DCI. Methods This is a prospective observational pilot study that includes seven patients with SAH. All patients underwent multimodality MRI including diffusion and perfusion imaging when there was concern for DCI. RAPID software was used to process diffusion and perfusion images and obtain threshold maps for diffusion restriction, Tmax prolongation and drops in cerebral blood volume (CBV), and cerebral blood flow (CBF). Correspondence of neuroanatomic location of focal perfusion alteration and pattern of perfusion alteration was evaluated. Results Neuroanatomical location of perfusion alteration corresponded to neurological symptoms in 86% (6/7) of patients. The prominent patterns were: prolongation of Tmax greater than four seconds (7/7), greater than 20% drop in CBF (3/7), and greater than 20% drop in CBV (3/7). Significant radiographic vasospasm on concurrently catheter angiogram and/or MR angiogram which corresponded to the supplying vessels to the neuroanatomic area with altered perfusion was seen in 71% (5/7) of the patients. Conclusions MRI‐perfusion imaging using RAPID software can help detect and quantify the presence of inadequate focal perfusion for DCI in real‐time. This tool could guide the timing and extent of endovascular vasodilatory and medical hyperdynamic treatment and larger studies of MRI‐perfusion imaging for DCI are warranted.

Alterations in cerebral distal vascular features and effect on cognition in a high cardiovascular risk population: A prospective longitudinal study

BackgroundAlterations in cerebral vasculature are instrumental in affecting cognition. Current studies mainly focus on proximal large arteries and small vessels, while disregarding morphology and blood flow of the arteries between them (medium-to-large arteries). MethodsIn this prospective study, two types of non-contrast enhanced magnetic resonance angiography (NCE-MRA) techniques, simultaneous non-contrast angiography and intraplaque hemorrhage (SNAP) and 3D Time-of-flight (TOF), were used to measure vascular morphologic features in medium-to-large intracranial arteries. Grey matter (GM) tissue level perfusion was assessed with arterial spin labeling (ASL) MRI. Twenty-seven subjects at high cardiovascular risk underwent baseline and 12-month follow-up MRI to compare the relationship between morphological features measured by NCE MRA, GM CBF by ASL MRI, and cognitive function measured by the Montreal Cognitive Assessment (MoCA). ResultsChanges in both global medium-to-large arteries and posterior cerebral (PCA) distal artery length and branch numbers, measured on SNAP MRA, were significantly associated with alterations in MoCA scores (P < 0.01), after adjusting for clinical confounding factors, total brain volume, and total white matter lesion (WML) volume. There were no associations between MoCA scores and vascular features on TOF MRA or ASL GM CBF. ConclusionsAlterations in vascular features of distal medium-to-large arteries may be more sensitive for detecting potential changes in cognition than cerebral blood flow alterations at the parenchymal level captured by perfusion ASL. Hemodynamic information from distal medium-to-large arteries provides an additional tool to advance understanding of the vascular contributions to cognitive function.

Impact of manual thrombus extraction on improving myocardial tissue level perfusion and left ventricular remodeling in ST segment elevation myocardial infarction: a prospective comparative study

Impact of manual thrombus extraction on improving myocardial tissue level perfusion and left ventricular remodeling in ST segment elevation myocardial infarction: a prospective comparative study

Reperfusion Microvascular Ischemia After Prolonged Coronary Occlusion: Implications And Treatment With Local Supersaturated Oxygen Delivery.

Following a prolonged coronary arterial occlusion, heterogeneously scattered, focal regions of low erythrocyte flow are commonly found throughout the reperfused myocardium. Experimental studies have also demonstrated the presence of widespread, focally patchy regions of microvascular ischemia during reperfusion (RMI). However, the potential contribution of RMI to tissue viability and function has received little attention in the absence of practical clinical methods for its detection. In this review, the anatomic/functional basis of RMI is summarized, along with the evidence for its presence in reperfused myocardium. Advances in microcirculation research related to obstructive responses of vascular endothelial cells and blood elements to the effects of hypoxia and low shear stress are discussed, and a potential cycle of intensification of RMI from such responses and progressive loss of functional capillary density is presented. In capillaries with impaired erythrocyte flow, compensatory increases in the delivery of oxygen, because of its low solubility in plasma, are effective only at high partial pressures. As discussed herein, attenuation of the cycle with oxygen at hyperbaric levels in plasma is, very likely, responsible for improved tissue level perfusion noted experimentally. Observed clinical benefits from intracoronary SuperSaturated oxygen (SSO2) delivery, including infarct size reduction, can be attributed to attenuation of RMI with improvement in microvascular blood flow.

Tissue characteristics of culprit lesion and myocardial tissue-level perfusion in non-ST-segment elevation acute coronary syndromes: The EARLY-MYO-ACS study

ObjectiveThe impact of tissue characteristics of culprit lesion on myocardial tissue-level perfusion in non-ST-segment elevation acute coronary syndrome (NSTE-ACS) remains unclear. EARLY-MYO-ACS study was a prospective observational study to investigate the relationship between pre-percutaneous coronary intervention (PCI) culprit plaque characteristics and post-PCI myocardial tissue-level perfusion with iMap intravascular ultrasound (IVUS) in NSTE-ACS patients. MethodsA total of 408 patients with coronary artery disease (246 NSTE-ACS and 162 stable angina pectoris) undergoing coronary angiography, grayscale-IVUS and iMap-IVUS were enrolled. Tissue characteristics of culprit lesion were analyzed by the iMap-IVUS system as fibrotic, lipidic, necrotic, or calcified tissue. Epicardial coronary perfusion was assessed by TIMI flow grade (TFG), and myocardial tissue-level perfusion was assessed by both TIMI myocardial perfusion grade (TMPG) and TIMI myocardial perfusion frame count (TMPFC). ResultsThe percentages of necrotic volume within the culprit lesion were significantly greater in NSTE-ACS than that in stable angina pectoris (20.8 ± 7.9% vs. 15.9 ± 7.2%, P < 0.001). Patients with impaired epicardial coronary perfusion (TFG 0–2) had higher necrotic percentage within the culprit lesion than those with normal TFG (27.9 ± 7.3% vs. 19.6 ± 7.4%, P < 0.001). Moreover, patients with impaired myocardial tissue-level perfusion (TMPG 0–2) had greater necrotic percentages within the culprit lesion than those with normal TMPG (25.0 ± 8.1% vs. 18.4 ± 6.7%, P < 0.001). Multivariate analysis revealed that iMap-derived necrotic volume percentage was independently associated with reduced post-PCI TMPG (OR 2.39 [95% CI 1.60 to 3.57], P = 0.009) and impaired post-PCI TMPFC (OR 2.89 [95% CI 1.62 to 5.16], P = 0.008). The ROC curve showed that the optimal threshold of necrotic volume percentage was 20.09% and 21.03% to predict impaired TMPG and TMPFC, respectively. ConclusionIncreased necrotic fraction of the culprit lesion is independently associated with impaired myocardial tissue-level perfusion in NSTE-ACS patients. Thus, plaque composition assessed by pre-PCI iMap-IVUS could predict post-PCI impaired myocardial tissue-level perfusion in NSTE-ACS patients (Trial Registration: ChiCTR-OCH-13003046).

Exercise Training Increases Parietal Lobe Cerebral Blood Flow in Chronic Stroke: An Observational Study.

Exercise is increasingly recommended as an essential component of stroke rehabilitation, yet uncertainty remains with respect to its direct effect on the cerebral vasculature. The current study first demonstrated the repeatability of pseudo-continuous arterial spin labeling (ASL) magnetic resonance imaging (MRI) in older adults with stroke, and then investigated the change in cerebrovascular function following a 6-month cardiovascular rehabilitation program. In the repeatability study, 12 participants at least 3 months post-stroke underwent two ASL imaging scans 1 month apart. In the prospective observational study, eight individuals underwent ASL imaging and aerobic fitness testing before and after a 6-month cardiovascular rehabilitation program. Cerebral blood flow (CBF) and the spatial coefficient of variation of CBF (sCoV) were quantified to characterize tissue-level perfusion and large cerebral artery transit time properties, respectively. In repeat scanning, intraclass correlation (ICC) indicated moderate test-retest reliability for global gray matter CBF (ICC = 0.73) and excellent reliability for sCoV (ICC = 0.94). In the observational study, gray matter CBF increased after training (baseline: 40 ± 13 vs. 6-month: 46 ± 12 ml·100 g−1·min−1, P = 0.036). The greatest change occurred in the parietal lobe (+18 ± 12%). Gray matter sCoV, however, did not change following training (P = 0.31). This study provides preliminary evidence that exercise-based rehabilitation in chronic stroke enhances tissue-level perfusion, without changing the relative hemodynamic properties of the large cerebral arteries.

Abstract WMP105: Quantitative Assessment of Cerebrovascular Reactivity in Paediatric Moyamoya

Background: Moyamoya disease is a progressive steno-occlusive arteriopathy that causes recurrent ischaemic events and neurological decline. Cerebrovascular reactivity (CVR) is an indicator of tissue level perfusion impairment and stroke risk. Quantitative BOLD MRI using carbon dioxide as a vasoactive stimulus has been validated in adults and region of CVR abnormality shown to be concordant with angiographic region of abnormality. However the evidence in paediatric literature remains scarce and mainly refers to the use of targeted-controlled delivery of CO2 which has limited utility in the paediatric population. Objective: To examine whether hypercapnic challenge BOLD CVR using endogenous CO2 in the awake (breath-hold [BH]) and sleep (general anaesthetic [GA]) state in children is reliable and repeatable. We also sought to explore whether regional abnormalities of CVR using these techniques were concordant with angiographic regions of abnormality. Method: Consecutive children with angiographic confirmation of MM had BH or GA CVR studies. All repeat studies - conducted on the same day in the same MRI session - were assessed for reliability and repeatability of qualitative measures of CVR. Results: Thirty seven children (16 male; median age MM diagnosis 8.61 years, range 0.6 - 16.7; median age at CVR 10.7 years, range 1.08-17.7) had CVR studies. Children who had a CVR study under GA were significantly younger at diagnosis of MM (mean age 7.4 years, range .67-16.58) compared to those studied using BH (mean age 10.47 years, range .83-15.58). CVR region of abnormality was concordant with region of angiographic abnormality. Twenty nine had repeat studies (14 GA, 15 BH). Intraclass correlation was fair (0.783, 95% confidence interval .534-.899) to excellent (.910, 95% confidence interval .577-.908) and agreement between repeat measures good. Conclusion: Qualitative measures of CVR using general anaesthetic and breath-hold techniques are reliable, repeatable and interpretable for use in clinical practice. However standardization of protocols would allow more reliable application of these tools for assessment of ischaemic risk in childhood cerebrovascular disease.

CRT-600.00 Tissue Characteristics of Culprit Lesion and Myocardial Tissue-level Perfusion in Non-ST-segment Elevation Acute Coronary Syndromes: Novel Findings from the IMAP-ACS-II Study Using 40-MHz Radiofrequency Intravascular Ultrasound Imaging System

The impact of tissue characteristics of culprit lesion on myocardial tissue-level perfusion in non-ST-segment elevation acute coronary syndrome (NSTE-ACS) has not been elucidated. The IMAP-ACS-II study was a prospective observational study to investigate the relationship between pre-percutaneous

Effect of Diltiazem on Coronary Artery Flow and Myocardial Perfusion in Patients With Isolated Coronary Artery Ectasia and Either Stable Angina Pectoris or Positive Myocardial Ischemic Stress Test

Isolated coronary artery ectasia (CAE) may be associated with stable or unstable coronary events despite the absence of epicardial coronary stenosis. Impaired coronary flow dynamics and myocardial perfusion have been demonstrated in stable patients with ectatic coronary arteries. We aimed to assess whether epicardial flow and tissue-level perfusion would be improved by diltiazem in myocardial regions subtended by the ectatic coronary arteries in patients with isolated CAE. A total of 60 patients with isolated CAE were identified of 9,780 patients who underwent elective coronary angiography. Patients were randomized to 5mg of intracoronary diltiazem or saline. Coronary blood flow of the microvascular network was assessed using myocardial blush grade (MBG) technique. The thrombolysis in myocardial infarction (TIMI) flow grade and TIMI frame count (TFC) were used to assess epicardial coronary flow. MBG (from 2.4 to 2.6, p= 0.02), TIMI flow grades (from 2.4 to 2.8, p <0.001), and TFC (from 35 to 26, p <0.001) were significantly improved after diltiazem, whereas no significant change was noticed after saline (from 2.4 to 2.4, p= 0.86 for MBG; from 2.3 to 2.3, p= 0.71 for TIMI flow grade; and from 35 to 33, p= 0.43 for TFC). Diltiazem provided amelioration of the altered coronary flow dynamics, which was suggested as the pathophysiological influence of CAE. In conclusion, the favorable effects of the diltiazem on myocardial perfusion were observed at both epicardial and tissue levels.

Prediction of myocardial tissue loss by quantitative densitometric myocardial blush parameters following ST-elevation myocardial infarction.

Tissue level myocardial perfusion is one of the most important prognostic factors after successful recanalisation of the occluded coronary artery in patients suffering acute ST elevation myocardial infarction (STEMI). The primary objective of the present study was to examine the relationship between videodensitometric myocardial perfusion parameters as assessed on coronary angiograms directly following successful recanalization therapy and magnetic resonance imaging (MRI)-derived myocardial tissue loss late after STEMI. The study comprised 29 STEMI patients. Videodensitometric parameter G(max)/T(max) was calculated to characterize myocardial perfusion, derived from the plateau of grey-level intensity (G(max)), divided by the time-to-peak intensity (Tmax). Myocardial loss index (MLI) was assessed by cardiac MRI following 376 ± 254 days after PCI. Significant correlations could be demonstrated between MLI and G(max) (r = 0.36, p = 0.05) and G(max)/T(max) (r = 0.40, p = 0.03) using vessel masking. Using receiver operating characteristic curve analysis, G(max)/T(max) < 2.17 predicted best MLI = 0.3, 0.4, 0.5 and 0.6 with good sensitivity and specificity data, while G(max)/T(max) < 3.25 proved to have a prognostic role in the prediction of MLI = 0.7. Selective myocardial tissue level perfusion quantitative measurement method is feasible and can serve as a good predictor of myocardial tissue loss following STEMI and revascularization therapy.

Reperfusion strategies in acute coronary syndromes.

The appropriate timing of angiography to facilitate revascularization is essential to optimize outcomes in patents with ST-segment-elevation myocardial infarction and non-ST-segment-elevation acute coronary syndromes. Timely reperfusion of the infarct-related coronary artery in ST-segment-elevation myocardial infarction both with fibrinolysis or percutaneous coronary intervention minimizes myocardial damage, reduces infarct size, and decreases morbidity and mortality. Primary percutaneous coronary intervention is the preferred reperfusion method if it can be performed in a timely manner. Strategies to reduce health system-related delays in reperfusion include regionalization of ST-segment-elevation myocardial infarction care, performing prehospital ECGs, prehospital activation of the catheterization laboratory, bypassing geographically closer nonpercutaneous coronary intervention-capable hospitals, bypassing the percutaneous coronary intervention-capable hospital emergency department, and early and consistent availability of the catheterization laboratory team. With implementation of such strategies, there has been significant improvement in process measures, including door-to-balloon time. However, despite reductions in door-to-balloon times, there has been little change during the past several years in in-hospital mortality, suggesting additional factors including patient-related delays, optimization of tissue-level perfusion, and cardioprotection must be addressed to improve patient outcomes further. Early angiography followed by revascularization when appropriate also reduces rates of death, MI, and recurrent ischemia in patients with non-ST-segment-elevation acute coronary syndromes, with the greatest benefits realized in the highest risk patients. Among patients with non-ST-segment-elevation acute coronary syndromes with multivessel disease, choice of revascularization modality should be made as in stable coronary artery disease, with a goal of complete ischemic revascularization.

Effect of Statin Pretreatment on Myocardial Perfusion in Patients Undergoing Primary Percutaneous Coronary Intervention: A Systematic Review and Meta‐analysis

To achieve sufficient myocardial perfusion in ST-segment elevation myocardial infarction (STEMI) patients receiving primary percutaneous coronary intervention (PPCI), many adjunctive therapies have been proposed. Previous trials have reported variances in myocardial perfusion improvement for statin pretreatment, which made it inconvincible to confirm the beneficial effects of statins. Therefore, we performed a systematic review and meta-analysis to determine whether statin pretreatment was effective in improving myocardial perfusion. Statin pretreatment could improve myocardial perfusion in STEMI patients undergoing PPCI. We searched the PubMed, Web of Knowledge, and the Cochrane Library databases for studies evaluating the impact of statin pretreatment on myocardial perfusion in STEMI patients receiving PPCI. Twelve trials were finally included in our meta-analysis. There were no significant differences in patients' baseline characteristics between the statin pretreatment and control groups. Overall pooled analysis showed that patients in the statin pretreatment groups had significantly better epicardial coronary blood flow (measured by Thrombosis in Myocardial Infarction [TIMI] grade, odds ratio [OR]: 0.49, 95% confidence interval [CI]: 0.28 to 0.84; measured by corrected TIMI frame count, mean difference: -5.63; 95% CI: -9.66 to -1.6). A trend toward myocardial tissue level perfusion improvement was seen in the statin pretreatment arm rather than the control arm (measured by myocardial blush grade, OR: 0.74; 95% CI: 0.50 to 1.09). This present meta-analysis suggests that statin pretreatment might be effective in improving myocardial perfusion in STEMI patients.

No-reflow: Incidence and Detection in The Cath-Lab

The primary goal in patients with ST-elevation myocardial infarction (STEMI) is the restoration of myocardial tissue-level perfusion. In a variable proportion of patients with STEMI, however, microcirculatory impairment may persist after epicardial coronary artery recanalization. This phenomenon is known as "myocardial no-reflow". Of note, no-reflow is associated with a worse prognosis both at short- and long-term follow-up. Depending on the population under study and the diagnostic technique used for its detection, the incidence of no-reflow ranges from 5 to 50%. No-reflow can be directly assessed in the cath-lab in several ways, including angiographic Thrombolysis in Myocardial Infarction (TIMI) flow grade assessment and more complex angiographic indexes, such as TIMI frame count, TIMI perfusion grade, myocardial blush grade, or by direct invasive assessment of coronary flow. After the cath-lab, both the evaluation of electrocardiographic ST-segment resolution and imaging techniques, as myocardial contrast echocardiography or cardiac magnetic resonance, are able to monitor no-reflow evolution, with imaging playing a crucial role in its quantification. In this article, we review indexes of no-reflow used both in the cath-lab and thereafter.

Microvascular Obstruction After Primary Percutaneous Coronary Intervention: Pathogenesis, Diagnosis and Prognostic Significance

The primary goal in reopening an infarct-related artery is the restoration of myocardial tissue-level perfusion. In a variable proportion of patients with ST-elevation myocardial infarction, however, microcirculatory impairment may persist after epicardial coronary artery recanalization. This phenomenon is known as microvascular obstruction (MVO). Ischemic injury, reperfusion injury, and distal embolization along with the individual response to each of these mechanisms are variably involved in the pathogenesis of MVO in the single patient. Importantly, MVO is associated with a worse prognosis both at short- and long-term follow-up. MVO can be assessed in the cath-lab by simple angiographic indexes, such as Thrombolysis in Myocardial Infarction grade score and Myocardial Blush Grade, or by invasive measures of coronary flow pattern. Imaging techniques, such as myocardial contrast echocardiography or cardiac magnetic resonance, and ST-segment resolution on standard electrocardiogram are used in the days following reperfusion with the patient in the coronary care unit. In this article, we review the available data regarding pathogenesis, diagnosis and the prognostic significance of MVO after primary percurtaneous coronary intervention in ST-elevation myocardial infarction patients, with a brief highlighting on the crucial role of its prevention and its early detection.

Microvascular Obstruction After Primary Percutaneous Coronary Intervention: Pathogenesis, Diagnosis and Prognostic Significance

The primary goal in reopening an infarct-related artery is the restoration of myocardial tissue-level perfusion. In a variable proportion of patients with ST-elevation myocardial infarction, however, microcirculatory impairment may persist after epicardial coronary artery recanalization. This phenomenon is known as microvascular obstruction (MVO). Ischemic injury, reperfusion injury, and distal embolization along with the individual response to each of these mechanisms are variably involved in the pathogenesis of MVO in the single patient. Importantly, MVO is associated with a worse prognosis both at short- and long-term follow-up. MVO can be assessed in the cath-lab by simple angiographic indexes, such as Thrombolysis in Myocardial Infarction grade score and Myocardial Blush Grade, or by invasive measures of coronary flow pattern. Imaging techniques, such as myocardial contrast echocardiography or cardiac magnetic resonance, and ST-segment resolution on standard electrocardiogram are used in the days following reperfusion with the patient in the coronary care unit. In this article, we review the available data regarding pathogenesis, diagnosis and the prognostic significance of MVO after primary percurtaneous coronary intervention in ST-elevation myocardial infarction patients, with a brief highlighting on the crucial role of its prevention and its early detection.

Vaporizing Thrombus With Excimer Laser Before Coronary Stenting Improves Myocardial Reperfusion in Acute Coronary Syndrome

Mechanical reperfusion has proven to be an unquestionably superior treatment strategy over that of thrombolytic therapy in patients with acute coronary syndrome (ACS). Excimer laser coronary angioplasty (ELCA) is a unique revascularization device that has a lytic effect on thrombus, in addition to its debulking effect on the atherosclerotic plaque beneath the thrombus. This single-center retrospective analysis consisted of consecutive ACS patients treated with ELCA (n=50) and age- and sex-matched ACS patients treated with manual aspiration (n=48) without use of a distal protection device. Success rate was judged by lesion crossability, procedure complications, and significant reduction of stenosis. Tissue-level perfusion was assessed on antegrade Thrombolysis In Myocardial Infarction (TIMI) flow grade, myocardial blush grade (MBG), and ST-segment elevation resolution (STR). Short-term outcome was evaluated according to occurrence of in-hospital major adverse cardiac events (MACE; myocardial infarction, target lesion revascularization, coronary artery bypass graft, and death). Lesion crossability was higher in the ELCA group than in the aspiration group (96.2% vs. 82.6%, P=0.04). Attainment of TIMI 3 flow (86.0% vs. 68.8%, P=0.04) and MBG 3 (76.0% vs. 54.2%, P=0.02) was also higher in the ELCA group than in the aspiration group. Complete STR was similar between the 2 groups. In-hospital MACE were significantly more frequent in the aspiration group. ELCA is feasible, safe, and effective for the treatment of patients with ACS and appears to be useful as an adjunctive lesion preparation device.

The never ending quest for an ideal angiographic surrogate of coronary reperfusion

Timely restoration of infarct related artery (IRA) patency by either pharmacological or mechanical treatment is the primary goal of reperfusion therapy in acute myocardial infarction (AMI). Early reperfusion improves myocardial salvage which in turn results in superior clinical outcomes. However, it has largely been recognized over the years that substantial number of patients may not achieve tissue level perfusion even after successful recanalization of the epicardial coronaries. This phenomenon is famously known as no-reflow, and has repeatedly been shown to be associated with increased morbidity and mortality following AMI reperfusion.1,2

Systemic endothelin receptor blockade in ST-segment elevation acute coronary syndrome protects the microvasculature: a randomised pilot study

ST-elevation acute coronary syndrome (STE-ACS) is characterised by compromised blood flow at the epicardial and microvascular levels. Endothelin-1 (ET-1) is a mediator of microvascular dysfunction and adverse cardiac remodelling. We hypothesised that administration of an endothelin type A (ETA) receptor antagonist (BQ-123; Clinalfa, Läufelfingen, Switzerland) may protect microvascular function. In this proof-of-concept, randomised, double-blind, placebo-controlled trial, patients with posterior-wall STE-ACS (n=57) were randomly assigned to receive intravenous BQ-123 at 400 nmol/minute or placebo over 60 minutes, starting at the onset of primary percutaneous coronary intervention (PCI). Time to myocardial contrast wash-in of the infarcted segment assessed by first-pass perfusion cardiac magnetic resonance imaging was the primary efficacy endpoint. Secondary endpoints included enzymatic infarct size and left ventricular ejection fraction (LVEF). In patients randomised to BQ-123 we observed shorter microvessel perfusion delays six days after PCI (1.8 sec [0.7-3.4] versus 3.3 sec [2.3-5.4] in placebo-treated patients, p=0.005). The treatment group demonstrated smaller enzymatic infarct sizes (p=0.014). All patients were alive at six months, with an LVEF of 63% (58-69) in patients randomised to BQ-123 and 59% (51-66) in placebo-treated patients (p=0.047). Administration of an ETA receptor blocker during primary PCI in patients with STE-ACS is safe and may improve tissue-level perfusion and LVEF.

Impact of Three Different Glycoprotein IIb/IIIa Antagonists on Glycoprotein IIb/IIIa Platelet Receptor Inhibition, Tissue Level Perfusion and Clinical Outcomes

Impact of Three Different Glycoprotein IIb/IIIa Antagonists on Glycoprotein IIb/IIIa Platelet Receptor Inhibition, Tissue Level Perfusion and Clinical Outcomes