Is the myocardial blush grade scored by the operator during primary percutaneous coronary intervention of prognostic value in patients with ST-elevation myocardial infarction in routine clinical practice?

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

Objectives

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

Methods

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

Results

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

Conclusion

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

Coronary No-Reflow after Primary Percutaneous Coronary Intervention-Current Knowledge on Pathophysiology, Diagnosis, Clinical Impact and Therapy

Coronary no-reflow (CNR) is a frequent phenomenon that develops in patients with ST-segment elevation myocardial infarction (STEMI) following reperfusion therapy. CNR is highly dynamic, develops gradually (over hours) and persists for days to weeks after reperfusion. Microvascular obstruction (MVO) developing as a consequence of myocardial ischemia, distal embolization and reperfusion-related injury is the main pathophysiological mechanism of CNR. The frequency of CNR or MVO after primary PCI differs widely depending on the sensitivity of the tools used for diagnosis and timing of examination. Coronary angiography is readily available and most convenient to diagnose CNR but it is highly conservative and underestimates the true frequency of CNR. Cardiac magnetic resonance (CMR) imaging is the most sensitive method to diagnose MVO and CNR that provides information on the presence, localization and extent of MVO. CMR imaging detects intramyocardial hemorrhage and accurately estimates the infarct size. MVO and CNR markedly negate the benefits of reperfusion therapy and contribute to poor clinical outcomes including adverse remodeling of left ventricle, worsening or new congestive heart failure and reduced survival. Despite extensive research and the use of therapies that target almost all known pathophysiological mechanisms of CNR, no therapy has been found that prevents or reverses CNR and provides consistent clinical benefit in patients with STEMI undergoing reperfusion. Currently, the prevention or alleviation of MVO and CNR remain unmet goals in the therapy of STEMI that continue to be under intense research.

Predictors of Hospital Mortality Based on Primary Angioplasty Treatment: A Multicenter Case-Control Study

BACKGROUND

Identification of high-risk patients undergoing primary angioplasty (PCI) is essential.

OBJECTIVE

Identify factors related to the causes of death in PCI patients.

METHODS

This work consisted of a multicenter case-control study using a Brazilian registry of cardiovascular interventions as the data source. The association between each variable and death was assessed using a binary logistic regression model, p <0.05 was considered significant.

RESULTS

A total of 26,990 records were analyzed, of which 18,834 (69.8%) were male patients, with a median age of 61 (±17) years. In the multivariate analysis, the main variables related to the causes of death with their respective odds ratios and 95%confidence intervals (CI) were advanced age, 70-79 years (2.46; 1.64-3.79) and ≥ 80 years (3.69; 2.38-5.81), p<0.001; the classification of Killip II (2.71; 1.92-3.83), Killip III (8.14; 5.67-11.64), and Killip IV (19.83; 14.85-26.69), p<0.001; accentuated global dysfunction (3.63; 2,39-5.68), p<0.001; and the occurrence of infarction after intervention (5.01; 2.57-9.46), p<0.001. The main protective factor was the post-intervention thrombolysis in myocardial infarction (TIMI) III flow (0.18; 0.13-0.24), p<0.001, followed by TIMI II (0.59; 0.41 -0.86), p=0.005, and male (0.79; 0.64-0.98), p = 0.032; dyslipidemia (0.69; 0.59-0.85), p<0.001; and number of lesions treated (0.86; 0.9-0.94), p<0.001.

CONCLUSION

The predictors of mortality in patients undergoing PCI were Killip's classification, reinfarction, advanced age, severe left ventricular dysfunction, female gender, and post-intervention TIMI 0 / I flow.

Prognostic Value of Myocardial Blush Grade in ST-elevation MI: A Systematic Review and Meta-analysis

Background: Ineffective myocardial perfusion despite angiographic success after angioplasty occurs frequently and is associated with an increased risk of mortality. Hence, this study determined whether myocardial perfusion measured by myocardial blush grade (MBG) identifies ST-elevation MI (STEMI) patients at high risk for poor outcomes after successful angioplasty. Methods: The search employed strategies designed for research databases. An article was eligible if it included adults who underwent coronary angioplasty for STEMI, post-angioplasty MBG was assessed, and mortality or major adverse cardiovascular events (MACE) were determined. Risk for bias was assessed using the Quality In Prognosis Studies tool and forest plots in a Mantel-Haenszel fixed effects model were created using RevMan5.4. Results/discussion: Eight observational studies with an overall low risk of bias were included, involving 8,044 patients. MBG 0/1 with no to poor myocardial perfusion had a negative prognostic value for mortality (OR 2.68; 95% CI [2.22–3.23]) and MACE (OR 1.20; 95% CI [1.01–1.41]). Furthermore, MBG 2 with moderate myocardial perfusion and MBG 3 with normal myocardial perfusion were associated with increased survival with a logHR of 0.47 (95% CI [0.43–0.52]) and 0.20 percutaneous coronary intervention (95% CI [0.18–0.23]). These results imply MBG is a useful prognostic marker for STEMI patients. Conclusion: MBG 0/1 after primary angioplasty is a strong negative prognostic marker for long-term all-cause mortality and MACE among STEMI patients, and a post-primary angioplasty MBG of 2 or 3 is a robust prognostic marker for long-term survival.

Intracoronary pharmacological therapy versus aspiration thrombectomy in STEMI (IPAT-STEMI): A systematic review and meta-analysis of randomized trials

BACKGROUND

Thrombus load in STEMI patients remains a challenge in practice. It aggravates coronary obstruction leading to impaired myocardial perfusion, worsened cardiac function, and adverse clinical outcomes. Various strategies have been advocated to reduce thrombus burden.

OBJECTIVES

This meta-analysis aimed to evaluate the effectiveness of intracoronary-administered thrombolytics or glycoprotein IIb/IIIa inhibitors (GPI) in comparison with aspiration thrombectomy (AT) as an adjunct to percutaneous coronary intervention (PCI) among patients presenting with ST-segment elevation myocardial infarction (STEMI).

METHODS

A comprehensive literature search for randomized trials that compared intracoronary-administered thrombolytics or GPI with AT in STEMI patients who underwent PCI, was conducted using various databases (e.g., MEDLINE, EMBASE, CENTRALE). Primary outcome was procedural measures (e.g., TIMI flow grade 3, TIMI myocardial perfusion grade (TMPG) 3, Myocardial blush grade (MBG) 2/3, ST-segment resolution (STR)).

RESULTS

Twelve randomized trials enrolled 1,466 patients: 696 were randomized to intracoronary-administered pharmacological interventions and 553 to AT. Patients randomized to PCI alone were excluded. Thrombolytics significantly improved TIMI flow grade 3 (odds ratio = 3.71, 95% CI: 1.85-7.45), complete STR (odds ratio = 3.64, 95% CI: 1.60-8.26), and TMPG 3 (odds ratio = 5.31, 95% CI: 2.48-11.36). Thrombolytics significantly reduced major adverse cardiovascular events (MACE) (odds ratio = 0.29, 95% CI: 0.13-0.65) without increasing bleeding risk. Trial sequential analysis assessment confirmed the superiority of thrombolytics for the primary outcome. Intracoronary GPI, either alone or combined with AT, did not improve procedural or clinical outcomes.

CONCLUSIONS

Compared with AT, intracoronary-administered thrombolytics significantly improved myocardial perfusion and MACE in STEMI patients.

A Narrative Review of the Classical and Modern Diagnostic Methods of the No-Reflow Phenomenon

The incidence of the no-reflow (NR) phenomenon varies depending on the diagnostic criteria used. If just the angiographic criteria are considered (i.e., a degree of thrombolysis in myocardial infarction ≤2), it will be found that the incidence of NR is quite low; on the other hand, when the myocardial NR is taken into account (i.e., a decrease in the quality of myocardial reperfusion expressed by the degree of myocardial blush), the real incidence is higher. Thus, the early establishment of a diagnosis of NR and the administration of specific treatment can lead to its reversibility. Otherwise, regardless of the follow-up period, patients with NR have a poor prognosis. In the present work, we offer a comprehensive perspective on diagnostic tools for NR detection, for improving the global management of patients with arterial microvasculature damage, which is a topic of major interest in the cardiology field, due to its complexity and its link with severe clinical outcomes.

Comparison of Intracoronary Epinephrine and Adenosine for No-Reflow in Normotensive Patients With Acute Coronary Syndrome (COAR Trial)

Background:

Intracoronary epinephrine has been effectively used in treating refractory no-reflow, but there is a dearth of data on its use as a first-line drug in normotensive patients in comparison to the widely used adenosine.

Methods:

In this open-labeled randomized clinical trial, 201 patients with no-reflow were randomized 1:1 into intracoronary epinephrine as the treatment group and intracoronary adenosine as the control group and followed for 1 month. The primary end points were improvement in coronary flow, as assessed by TIMI (Thrombolysis in Myocardial Infarction) flow, frame counts, and myocardial blush. Secondary end points were in-hospital and short-term mortality and major adverse cardiac events.

Results:

In all, 101 patients received intracoronary epinephrine and 100 patients received adenosine. Epinephrine was generally well tolerated with no immediate table death or ventricular fibrillation. No-reflow was more effectively improved with epinephrine with final TIMI III flow (90.1% versus 78%, P=0.019) and final corrected TIMI frame count (24±8.43 versus 26.63±9.22, P=0.036). However, no significant difference was observed in final grade III myocardial blush (55.4% versus 45%, P=0.139), mean reduction of corrected TIMI frame count (−25.71±11.79 versus −26.08±11.71, P=0.825), in-hospital and short-term mortality, and major adverse cardiac events.

Conclusions:

Epinephrine is relatively safe to use in no-reflow in normotensive patients. A significantly higher frequency of post-treatment TIMI III flow grade and lower final corrected TIMI frame count with relatively better achievement of myocardial blush grade III translate into it displaying relatively better efficacy than adenosine.

Registration:

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04699110.

Accuracy of Post-thrombolysis ST-segment Reduction as an Adequate Reperfusion Predictor in the Pharmaco-Invasive Approach

Fundamento

A intervenção coronária percutânea primária é considerada o “padrão-ouro” para reperfusão coronária. Entretanto, quando não disponível, a estratégia fármaco-invasiva é método alternativo, e o eletrocardiograma (ECG) tem sido utilizado para identificar sucesso na reperfusão.

Objetivos

Nosso estudo teve como objetivo examinar alterações no segmento-ST pós-lise e seu poder de prever a recanalização, usando os escores angiográficos TIMI e blush miocárdio (MBG) como critério de reperfusão ideal.

Métodos

Foram estudados 2.215 pacientes com infarto agudo do miocárdio com supra-ST submetidos à fibrinólise [(Tenecteplase)-TNK] e encaminhados para angiografia coronária em até 24 h pós-fibrinólise ou imediatamente encaminhados à terapia de resgate. O ECG foi realizado pré-TNK e 60 min-pós. Os pacientes foram categorizados em dois grupos: aqueles com reperfusão ideal (TIMI-3 e MBG-3) e aqueles com reperfusão inadequada (fluxo TIMI <3). Foi definido o critério de reperfusão do ECG pela redução do segmento ST >50%. Consideramos p-valor <0,05 para as análises, com testes bicaudais.

Resultados

O critério de reperfusão pelo ECG apresentou valor preditivo positivo de 56%; valor preditivo negativo de 66%; sensibilidade de 79%; e especificidade de 40%. Houve fraca correlação positiva entre a redução do segmento-ST e os dados angiográficos de reperfusão ideal (r = 0,21; p <0,001) e baixa precisão diagnóstica, com AUC de 0,60 (IC-95%; 0,57-0,62).

Conclusão

Em nossos resultados, a redução do segmento-ST não conseguiu identificar com precisão os pacientes com reperfusão angiográfica apropriada. Portanto, mesmo pacientes com reperfusão aparentemente bem-sucedida devem ser encaminhados à angiografia brevemente, a fim de garantir fluxo coronário macro e microvascular adequados.

SARS-COV-2 colonizes coronary thrombus and impairs heart microcirculation bed in asymptomatic SARS-CoV-2 positive subjects with acute myocardial infarction

BACKGROUND

The viral load of asymptomatic SAR-COV-2 positive (ASAP) persons has been equal to that of symptomatic patients. On the other hand, there are no reports of ST-elevation myocardial infarction (STEMI) outcomes in ASAP patients. Therefore, we evaluated thrombus burden and thrombus viral load and their impact on microvascular bed perfusion in the infarct area (myocardial blush grade, MBG) in ASAP compared to SARS-COV-2 negative (SANE) STEMI patients.

METHODS

This was an observational study of 46 ASAP, and 130 SANE patients admitted with confirmed STEMI treated with primary percutaneous coronary intervention and thrombus aspiration. The primary endpoints were thrombus dimension + thrombus viral load effects on MBG after PPCI. The secondary endpoints during hospitalization were major adverse cardiovascular events (MACEs). MACEs are defined as a composite of cardiovascular death, nonfatal acute AMI, and heart failure during hospitalization.

RESULTS

In the study population, ASAP vs. SANE showed a significant greater use of GP IIb/IIIa inhibitors and of heparin (p < 0.05), and a higher thrombus grade 5 and thrombus dimensions (p < 0.05). Interestingly, ASAP vs. SANE patients had lower MBG and left ventricular function (p < 0.001), and 39 (84.9%) of ASAP patients had thrombus specimens positive for SARS-COV-2. After PPCI, a MBG 2-3 was present in only 26.1% of ASAP vs. 97.7% of SANE STEMI patients (p < 0.001). Notably, death and nonfatal AMI were higher in ASAP vs. SANE patients (p < 0.05). Finally, in ASAP STEMI patients the thrombus viral load was a significant determinant of thrombus dimension independently of risk factors (p < 0.005). Thus, multiple logistic regression analyses evidenced that thrombus SARS-CoV-2 infection and dimension were significant predictors of poorer MBG in STEMI patients. Intriguingly, in ASAP patients the female vs. male had higher thrombus viral load (15.53 ± 4.5 vs. 30.25 ± 5.51 CT; p < 0.001), and thrombus dimension (4.62 ± 0.44 vs 4.00 ± 1.28 mm2; p < 0.001). ASAP vs. SANE patients had a significantly lower in-hospital survival for MACE following PPCI (p < 0.001).

CONCLUSIONS

In ASAP patients presenting with STEMI, there is strong evidence towards higher thrombus viral load, dimension, and poorer MBG. These data support the need to reconsider ASAP status as a risk factor that may worsen STEMI outcomes.

Relationship of serum vitamin D levels with coronary thrombus grade, TIMI flow, and myocardial blush grade in patients with acute ST-segment elevation myocardial infarction

BACKGROUND

Vitamin D deficiency is a prevalent condition that is found in about 30-50% of the general population, and it is increasing as a new risk factor for coronary artery disease. Our study aimed to evaluate the relationship of serum vitamin D levels with coronary thrombus burden, Thrombolysis In Myocardial Infarction flow grade, and myocardial blush grade in patients managed by primary percutaneous coronary intervention for their first acute ST-segment elevation myocardial infarction.

RESULTS

Eighty patients were included in the study with their first acute ST-segment elevation myocardial infarction and were managed by primary percutaneous coronary intervention. According to the serum concentrations of vitamin D, the study population was divided into 2 groups: group A with abnormal vitamin D levels less than 30 ng/ml (50 patients) and group B with normal vitamin D levels equal to or more than 30 ng/ml (30 patients). Angiographic data was recorded before and after coronary intervention. On comparing thrombus grade and initial and post-procedural Thrombolysis In Myocardial Infarction flow between both groups of patients, there was no significant difference (p = 0.327, p = 0.692, p = 0.397). However, myocardial blush grade was better in patients with normal vitamin D levels (p = 0.029) without a significant correlation between vitamin D concentration values and myocardial blush grade (r = 0.164, p = 0.146).

CONCLUSIONS

Patients with first acute ST-segment elevation myocardial infarction and normal vitamin D levels undergoing primary percutaneous coronary intervention had better myocardial blush grade and more successful microvascular reperfusion in comparison with patients with abnormal vitamin D levels. There was no significant difference between the normal and abnormal vitamin D groups regarding the coronary thrombus grade and Thrombolysis In Myocardial Infarction flow.

Myocardial reperfusion with tirofiban injection via aspiration catheter : Efficacy and safety in STEMI patients with large thrombus burden

BACKGROUND

There is no consensus on the use of thrombus aspiration (TA) in primary percutaneous coronary intervention (PPCI), and few studies have focused on the performance of tirofiban via TA catheter after PPCI. Our study investigated the clinical outcome of tirofiban injection through TA in acute ST-segment elevation myocardial infarction (STEMI) patients with large thrombus burden undergoing PPCI treatment.

PATIENTS AND METHODS

The study comprised 122 STEMI patients who underwent TA during PPCI. Participants were randomly divided into two groups. Group A received intravenous tirofiban injection and tirofiban injection via a TA catheter to the infarcted coronary artery after aspiration (n = 61). Group B received intravenous tirofiban injection only (n = 61). Baseline clinical information and follow-up data were collected for both groups. Coronary angiography, electrocardiography, and echocardiography findings as well as major adverse cardiovascular events (MACE) were recorded.

RESULTS

There were significant differences in postprocedural Thrombolysis in Myocardial Infarction (TIMI) grade 2 and 3 flow between the two groups (p = 0.021, p = 0.006, respectively). The incidence of slow-flow in group A was significantly lower than that of group B (p = 0.011). An increased incidence of no ST-segment resolution was observed in group B (p = 0.011). There were fewer major adverse cardiovascular events in group A than in group B, but the difference was not statistically significant.

CONCLUSION

Selective tirofiban injection via TA catheter during PPCI may improve myocardial reperfusion in STEMI patients with large thrombus burden.

Interhospital transfer due to failed prehospital diagnosis for primary percutaneous coronary intervention: an observational study on incidence, predictors, and clinical impact

BACKGROUND

For patients with ST-elevation myocardial infarction (STEMI), guidelines recommend prehospital triage and direct referral to a percutaneous coronary intervention (PCI)-capable centre in order to minimize ischemic time. However, few have studied failed prehospital diagnosis. We assessed the incidence, predictors, and clinical impact of interhospital transfer for primary PCI after initial referral to a non-PCI-capable centre due to a failed prehospital STEMI diagnosis.

METHODS

We studied 846 consecutive STEMI patients undergoing primary PCI between January 2008 and January 2010.

RESULTS

We found that 609 patients (72%) were directly admitted through prehospital triage and 127 patients (15%) required interhospital transfer after failed prehospital diagnosis. Median first medical contact to treatment time was 88 min in the prehospital diagnosis group and 155 min in the interhospital transfer group (p<0.001). In the interhospital transfer group, the first available electrocardiogram was diagnostic for STEMI in 77% of cases. Predictors of interhospital transfer were female gender, diabetes, prior myocardial infarction, and greater event location to PCI-capable centre distance. Interhospital transfer independently accounted for a 47% increase in ischemic time (95% CI 33 to 63%; p<0.001). One-year mortality was higher in the interhospital transfer group (10 vs. 5.3%; p=0.030).

CONCLUSIONS

Despite an often-diagnostic electrocardiogram, interhospital transfer after failed prehospital diagnosis occurred in 15% of STEMI patients undergoing primary PCI. Interhospital transfer was a major predictor of ischemic time and 1-year mortality was significantly higher. Continuing efforts to optimize prehospital triage are warranted, especially among patients at higher risk of failed prehospital diagnosis.

Myocardial tissue perfusion predicts the evolution of fragmented QRS in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

BACKGROUND

Fragmented QRS complex (fQRS) is associated with worse outcomes in several cardiovascular conditions. However, alterations in fQRS in patients with ST elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PCI) and association of fQRS with myocardial blush grade (MBG) has not been investigated until now. In this study, we aimed to investigate the association of MBG after primary PCI with evolution of fQRS.

METHODS

Our study consisted of 401 consecutive patients with STEMI who underwent primary PCI. Patients were categorized into two subgroups according to persistence or new-onset of fQRS (Group 1) and absence or resolution of fQRS (Group 2) at 48 hours after primary PCI. The evolution of fQRS on pre- and post-PCI ECG and their relation with myocardial reperfusion parameters were investigated.

RESULTS

Patients in group 1 showed older age, higher rate of smoking, lower HDL-cholesterol, lower LVEF, higher angina-to-door time, higher TIMI frame count, and high rate of patients with MBG <3 compared to patients with group 2 (P < 0.05). In correlation analysis, LVEF showed positive correlation with MBG (r = 0.448, P < 0.001) and negative correlation with the number of leads with fQRS (r = -0.335, P < 0.001). In multivariate regression analysis, new-onset or persistance of fQRS after primary PCI is significantly associated with MBG <3, peak CK-MB level, pre-PCI fQRS at anterior localization and smoking.

CONCLUSION

Our findings showed that despite complete ST-segment resolution in all patients, fQRS is independently associated with impaired microvascular myocardial perfusion. So, fQRS, as a simple and easily available noninvasive marker, may be useful in stratification of high-risk patients with increased extent of infarcted myocardium who underwent primary PCI.

Implications of ST-segment elevation in leads V5 and V6 in patients with reperfused inferior wall acute myocardial infarction

During inferior acute myocardial infarction, ST-segment elevation (ST↑) often occurs in leads V(5) to V(6), but its clinical implications remain unclear. We examined the admission electrocardiograms from 357 patients with a first inferior acute myocardial infarction who had Thrombolysis In Myocardial Infarction 3 flow of the right coronary artery or left circumflex artery within 6 hours after symptom onset. The patients were divided according to the presence (n = 76) or absence (n = 281) of ST↑ >2 mm in leads V(5) and V(6). Patients with ST↑ in leads V(5) and V(6) were subdivided into 2 groups according to the degree of ST↑ in leads III and V(6): ST↑ in lead III greater than in V(6) (n = 53) and ST↑ in lead III equal to or less than in V(6) (n = 23). The perfusion territory of the culprit artery was assessed using the angiographic distribution score, and a mega-artery was defined as a score of ≥0.7. ST↑ in leads V(5) and V(6) with ST↑ in lead III greater than in V(6) and ST↑ in leads V(5) and V(6) with ST↑ in lead III equal to or less than in V(6) were associated with mega-artery occlusion and impaired myocardial reperfusion, as defined by myocardial blush grade 0 to 1. Right coronary artery occlusion was most common (96%) in the former, and left circumflex artery occlusion was most common (96%) in the latter, especially proximal left circumflex occlusion (74%). Multivariate analysis showed that ST↑ in leads V(5) and V(6) with ST↑ in lead III greater than that in V(6) (odds ratio 4.81, p <0.001) and ST↑ in leads V(5) and V(6) with ST↑ in lead III equal or less than that in V(6) (odds ratio 5.96, p <0.001) were independent predictors of impaired myocardial reperfusion. In conclusion, ST↑ in leads V(5) and V(6) suggests a greater risk area and impaired myocardial reperfusion in patients with inferior acute myocardial infarction. Furthermore, comparing the degree of ST↑ in lead V(6) with that in lead III is useful for predicting the culprit artery.

Circulation: Cardiovascular Quality and Outcomes Editors' Picks

The following are highlights from the new series, Circulation: Cardiovascular Quality and Outcomes Topic Review. This series will summarize the most important manuscripts, as selected by the editors, that have published in the Circulation portfolio. The objective of this new series is to provide our readership with a timely, comprehensive selection of important papers that are relevant to the quality and outcomes and general cardiology audience. The studies included in this article represent the most significant research in the area of ST-segment elevation myocardial infarction care and address improvements in the timeliness of care, strategies for initial treatment—particularly with respect to reperfusion therapies—and trends.

Quantitative Blush Evaluator accurately quantifies microvascular dysfunction in patients with ST-elevation myocardial infarction: comparison with cardiovascular magnetic resonance

BACKGROUND

After ST-elevation myocardial infarction (STEMI), microvascular obstruction (MVO) can be assessed using semiquantitative angiographic "blush" scores subject to interoperator variability. Quantitative Blush Evaluator (QuBE) is a free computer-calculated algorithm that evaluates myocardial blush on a continuous scale with improved reproducibility. We aimed to compare QuBE with cardiovascular magnetic resonance (CMR) in detecting MVO and its severity.

METHODS

Fifty-two STEMI treated with successful primary percutaneous coronary intervention were enrolled. Quantitative Blush Evaluator and electrocardiographic sum ST-segment resolution were blindly calculated. All patients underwent CMR 4 to 7 days after STEMI for assessment of infarct size (IS), myocardial salvage index, MVO (both as first-pass MVO and delayed-enhancement MVO [DE-MVO]), and presence of intramyocardial hemorrhage on T2-weighted sequences.

RESULTS

Quantitative Blush Evaluator values were inversely related to IS (R = -0.4, P = .008), DE-MVO (R = -0.7, P < .001), and first-pass MVO (R = -0.4, P = .002) and positively related to myocardial salvage index (R = 0.4, P = .007). Moreover, patients with intramyocardial hemorrhage had significantly lower QuBE values (3.9, 3.5-8.0 vs 12.2, 8.2-16.0, P = .001) than those without. At receiver operating characteristic curve analysis, QuBE accounted for an area under the curve of 0.88 (95% CI 0.7-0.9, P = .001) for both DE-MVO and hemorrhage detection and performed significantly better than ST resolution.

CONCLUSIONS

Quantitative Blush Evaluator score correlates with IS and microvascular dysfunction by CMR and can be considered as an accurate tool for the assessment of MVO in clinical practice. Quantitative Blush Evaluator is a useful quantitative angiographic technique for the assessment of myocardial reperfusion after STEMI.

Angiographic assessment of microvascular perfusion--myocardial blush in clinical practice

Assessment of myocardial "blush" by either Myocardial Blush Grade or TIMI Myocardial Perfusion Grade, is the angiographic method currently preferred to confirm myocardial tissue-level perfusion after primary percutaneous intervention. This review focuses on the utility of angiographic "blush" as a simple, widely available, and virtually costless technique for the immediate diagnosis of microvascular impairment at the time of acute catheterization. We comprehensively outline the available evidence behind the "blush," its use in clinical practice, and draw comparisons with other new technologies for assessment of microvascular integrity.