Intracoronary Near-Infrared Spectroscopy to Predict No-Reflow Phenomenon During Percutaneous Coronary Intervention in Acute Coronary Syndrome

Near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) can identify the lipid-rich lesions, described as high lipid-core burden index (LCBI). The aim of this study was to investigate the relation between lipid-core plaque (LCP) in the infarct-related lesion detected using NIRS-IVUS and no-reflow phenomenon during percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS). We investigated 371 patients with ACS who underwent NIRS-IVUS in the infarct-related lesions before PCI. The extent of LCP in the infarct-related lesion was calculated as the maximum LCBI for each of the 4-mm longitudinal segments (maxLCBI4mm) measured by NIRS-IVUS. The patients were divided into 2 groups using a maxLCBI4mm cut-off value of 400. The overall incidence of no-reflow phenomenon was 53 of 371 (14.3%). No-reflow phenomenon more frequently occurred in patients with maxLCBI4mm ≥400 compared with those with maxLCBI4mm<400 (17.5% vs 2.5%, p <0.001). After propensity score matching, multivariable logistic regression analysis demonstrated that maxLCBI4mm (odds ratio: 1.008; 95% confidence interval: 1.005 to 1.012, p <0.001) was independently associated with the no-reflow phenomenon. The maxLCBI4mm of 719 in the infarct-related lesion had the highest combined sensitivity (69.8%) and specificity (72.1%) for the identification of no-reflow phenomenon. In conclusion, in patients with ACS, maxLCBI4mm in the infarct-related lesion assessed by NIRS-IVUS was independently associated with the no-reflow phenomenon during PCI.

Negative Impact of Acute Reloading after Mechanical Left Ventricular Unloading

Mechanical LV unloading for acute myocardial infarction (MI) is a promising supportive therapy to reperfusion. However, no data is available on exit strategy. We evaluated hemodynamic and cellular effects of reloading after Impella-mediated LV unloading in Yorkshire pigs. First, we conducted an acute study in normal heart to observe effects of unloading and reloading independent of MI-induced ischemic effects. We then completed an MI study to investigate optimal exit strategy on one-week infarct size, no-reflow area, and LV function with different reloading speeds. Initial studies showed that acute reloading causes an immediate rise in end-diastolic wall stress followed by a significant increase in cardiomyocyte apoptosis. The MI study did not result in any statistically significant findings; however, numerically smaller average infarct size and no-reflow area in the gradual reloading group prompt further examination of reloading approach as an important clinically relevant consideration.

The non-HDL-C/HDL-C ratio is a strong and independent predictor of the no-reflow phenomenon in patients with ST-elevation myocardial infarction

BACKGROUND

No-reflow (NR) is the inability to achieve adequate myocardial perfusion despite successful restoration of attegrade blood flow in the infarct-related artery after primary percutaneous coronary intervention. The non-HDL-C/HDL-C ratio has been shown to be superior to conventional lipid markers in predicting most cardiovascular diseases. In this study, we wanted to reveal the predictive value of the NR by comparing the Non-HDL-C/HDL-C ratio with traditional and non-traditional lipid markers in patients who underwent primary percutaneous coronary intervention (pPCI) due to ST-elevation myocardial infarction (STEMI).

METHODS

A total of 1284 consecutive patients who underwent pPCI for STEMI were included in this study. Traditional lipid profiles were detected and non-traditional lipid indices were calculated. Patients were classified as groups with and without NR and compared in terms of lipid profiles.

RESULTS

No-reflow was seen in 18.8% of the patients. SYNTAX score, maximal stent length, high thrombus burden, atherogenic index of plasma and non-HDL-C/HDL-C ratio were determined as independent predictors for NR (p < 0.05, for all). The non-HDL-C/HDL-C ratio predicts the development of NR in STEMI patients with 71% sensitivity and 67% specificity at the best cut-off value. In ROC curve analysis, the non-HDL-C/HDL-C ratio was superior to traditional and non-traditional lipid markers in predicting NR (p < 0.05, for all).

CONCLUSION

The non-HDL-C/HDL-C ratio can be a strong and independent predictor of NR in STEMI patients and and therefore non-HDL-C/HDL-C ratio may be a useful lipid-based biomarker that can be used in clinical practice to improve the accuracy of risk assessment in patients with STEMI.

No-Reflow Prediction in Acute Coronary Syndrome During Percutaneous Coronary Intervention: The NORPACS Risk Score

BACKGROUND

Suboptimal coronary reperfusion (no reflow) is common in acute coronary syndrome percutaneous coronary intervention (PCI) and is associated with poor outcomes. We aimed to develop and externally validate a clinical risk score for angiographic no reflow for use following angiography and before PCI.

METHODS

We developed and externally validated a logistic regression model for prediction of no reflow among adult patients undergoing PCI for acute coronary syndrome using data from the Melbourne Interventional Group PCI registry (2005-2020; development cohort) and the British Cardiovascular Interventional Society PCI registry (2006-2020; external validation cohort).

RESULTS

A total of 30 561 patients (mean age, 64.1 years; 24% women) were included in the Melbourne Interventional Group development cohort and 440 256 patients (mean age, 64.9 years; 27% women) in the British Cardiovascular Interventional Society external validation cohort. The primary outcome (no reflow) occurred in 4.1% (1249 patients) and 9.4% (41 222 patients) of the development and validation cohorts, respectively. From 33 candidate predictor variables, 6 final variables were selected by an adaptive least absolute shrinkage and selection operator regression model for inclusion (cardiogenic shock, ST-segment-elevation myocardial infarction with symptom onset >195 minutes pre-PCI, estimated stent length ≥20 mm, vessel diameter <2.5 mm, pre-PCI Thrombolysis in Myocardial Infarction flow <3, and lesion location). Model discrimination was very good (development C statistic, 0.808; validation C statistic, 0.741) with excellent calibration. Patients with a score of ≥8 points had a 22% and 27% risk of no reflow in the development and validation cohorts, respectively.

CONCLUSIONS

The no-reflow prediction in acute coronary syndrome risk score is a simple count-based scoring system based on 6 parameters available before PCI to predict the risk of no reflow. This score could be useful in guiding preventative treatment and future trials.

The stress hyperglycemic ratio can predict the no-reflow phenomenon following saphenous vein graft intervention in patients with acute coronary syndrome

AIMS

The no-reflow phenomenon (NRP) is a common complication of saphenous vein graft (SVG) interventions. The aim of this study was to investigate the effect of the stress hyperglycemia ratio (SHR) on the development of NRP in patients with acute coronary syndrome (ACS) undergoing percutaneous SVG intervention.

METHODS

The study included 223 patients who presented at our center with ACS, had a history of coronary artery bypass graft and underwent a saphenous graft procedure. The relationship between SHR calculated at the time of presentation from glucose and HbA1c values, and the development of NRP evaluated after the procedure with angiography was determined with univariate and multivariate binary regression analysis.

RESULT

The study population was separated into two groups as those who developed and did not develop NRP. Mean age was determined to be significantly higher in the group that did not develop NRP compared to the group with NRP (p: 0.004). Angiographically, the thrombus burden was determined to be significantly higher in the group that developed NRP (p < 0.001). Patients were separated into 3 tertiles according to the SHR level (T1, T2, T3), and the rate of NRP development was determined at a significantly higher rate in the T3 group (p < 0.001).

CONCLUSIONS

This study showed that SHR, a parameter that can be easily calculated noninvasively, is an independent predictor of NRP development in ACS patients undergoing saphenous interventions. In addition, high thrombus burden and predilatation before stenting were also found to be factors that increase the likelihood of developing NRP.

The predictive value of laboratory parameters for no-reflow phenomenon in patients with ST-elevation myocardial infarction following primary percutaneous coronary intervention: A meta-analysis

To date, the predictive role of laboratory indicators for the phenomenon of no flow is unclear. Hence, our objective was to conduct a meta-analysis to investigate the association between laboratory parameters and the risk of the no-reflow phenomenon in patients with ST-elevation myocardial infarction (STEMI) following primary percutaneous coronary intervention (PCI). This, in turn, aims to offer valuable insights for early clinical prediction of no-reflow. We searched Pubmed, Embase, and Cochrane Library from the establishment of the database to October 2023. We included case-control or cohort study that patients with STEMI following primary PCI. We excluded repeated publication, research without full text, incomplete information or inability to conduct data extraction and animal experiments, reviews, and systematic reviews. STATA 15.1 was used to analyze the data. The pooled results indicated that elevated white blood cell (WBC) count (odds ratio [OR] = 1.061, 95% confidence interval [CI]: 1.013-1.112), neutrophil count (OR = 1.324, 95% CI: 1.128-1.553), platelet (PLT) (OR = 1.002, 95% CI: 1.000-1.005), blood glucose (OR = 1.005, 95% CI: 1.002-1.009), creatinine (OR = 1.290, 95% CI: 1.070-1.555), total cholesterol (TC) (OR = 1.022, 95% CI: 1.012-1.032), d-dimer (OR = 1.002, 95% CI: 1.001-1.004), and fibrinogen (OR = 1.010, 95% CI: 1.005-1.015) were significantly associated with increased risk of no-reflow. However, elevated hemoglobin was significantly associated with decreased risk of no-reflow. In conclusion, our comprehensive analysis highlights the predictive potential of various parameters in assessing the risk of no-reflow among STEMI patients undergoing PCI. Specifically, WBC count, neutrophil count, PLT, blood glucose, hemoglobin, creatinine, TC,  d-dimer, and fibrinogen emerged as significant predictors. This refined risk prediction may guide clinical decision-making, allowing for more targeted and effective preventive measures to mitigate the occurrence of no-reflow in this patient population.

No-reflow after stroke reperfusion therapy: An emerging phenomenon to be explored

In the field of stroke thrombectomy, ineffective clinical and angiographic reperfusion after successful recanalization has drawn attention. Partial or complete microcirculatory reperfusion failure after the achievement of full patency of a former obstructed large vessel, known as the "no-reflow phenomenon" or "microvascular obstruction," was first reported in the 1960s and was later detected in both experimental models and patients with stroke. The no-reflow phenomenon (NRP) was reported to result from intraluminal occlusions formed by blood components and extraluminal constriction exerted by the surrounding structures of the vessel wall. More recently, an emerging number of clinical studies have estimated the prevalence of the NRP in stroke patients following reperfusion therapy, ranging from 3.3% to 63% depending on its evaluation methods or study population. Studies also demonstrated its detrimental effects on infarction progress and neurological outcomes. In this review, we discuss the research advances, underlying pathogenesis, diagnostic techniques, and management approaches concerning the no-reflow phenomenon in the stroke population to provide a comprehensive understanding of this phenomenon and offer references for future investigations.

Triglyceride glucose-body mass index as a novel predictor of slow coronary flow phenomenon in patients with ischemia and nonobstructive coronary arteries (INOCA)

BACKGROUND

The triglyceride glucose-body mass index (TyG-BMI index) has been suggested as a novel predictor of insulin resistance. However, its predictive value for slow coronary flow phenomenon (SCFP) in patients with ischemia and nonobstructive coronary arteries (INOCA) remains unclear.

METHODS

We consecutively recruited 1625 patients with INOCA from February 2019 to February 2023 and divided them into two groups based on thrombolysis in myocardial infarction (TIMI) frame counts (TFCs): the SCFP group (n = 79) and the control group. A 1:2 age-matched case-control study was then performed. The TyG-BMI index was calculated as ln [plasma triglyceride (mg/dL) × fasting blood glucose (mg/dL)/2] × BMI.

RESULTS

TyG-BMI index in the SCFP group (218.3 ± 25.2 vs 201.0 ± 26.5, P < .001) was significantly higher than in the normal controls. TyG-BMI index also increased with the number of coronary arteries involved in the SCFP. Multivariate logistic regression analysis showed that TyG-BMI, BMI, and TG were independent predictors for SCFP. Receiver operating characteristic (ROC) curve analysis showed that when the TyG-BMI index was above 206.7, the sensitivity and specificity were 88.6% and 68.5%, respectively, with an AUC of 0.809 (95% CI: 0.756-0.863, P = .027). Combined BMI with TG, the TyG-BMI index had a better predictive value for SCFP than BMI and TG (P < .001).

CONCLUSION

The TyG-BMI index was an independent predictor for SCFP in INOCA patients, and it had a better predictive value than BMI and TG.

Pan-Immune-Inflammation Value Is Independently Correlated to Impaired Coronary Flow After Primary Percutaneous Coronary Intervention in Patients With ST-Segment Elevation Myocardial Infarction

Immune-inflammatory biomarkers have been shown to be correlated with impaired coronary flow (ICF) in ST-segment elevation myocardial infarction. In this study, we assessed the relation between a novel comprehensive biomarker, pan-immune-inflammation value (PIV), and ICF after primary percutaneous coronary intervention (pPCI) in ST-segment elevation myocardial infarction. A total of 687 patients who underwent pPCI between 2019 and 2023 were retrospectively analyzed. Blood samples were collected at admission. PIV and other inflammation parameters were compared. PIV was calculated as (neutrophil count × platelet count × monocyte count)/lymphocyte count. Postprocedural coronary flow was assessed by thrombolysis in myocardial infarction (TIMI) classification. Patients were divided into 2 groups: a group with ICF defined as postprocedural TIMI 0 to 2 and a group with normal coronary flow defined as postprocedural TIMI flow grade of 3. The mean age was 61 ± 12 years, and 22.4% of the patients were women. Compared with the normal coronary flow group (median 492, interquartile range 275 to 931), the ICF group (median 1,540, interquartile range 834 to 2,909) showed significantly increased PIV (p <0.001). The optimal cutoff for the PIV was 804, as determined by receiver operating characteristic curve. The incidence of ICF was 17.0% in all patients, 6.4% in low-PIV group (<804), and 34.2% in high-PIV group (≥804). Multivariate analyses revealed that a baseline PIV ≥804 was independently associated with post-pPCI ICF (odds ratio 5.226, p <0.001). PIV was superior to neutrophil/lymphocyte ratio and platelet/lymphocyte ratio in determining ICF. In conclusion, a high-PIV was significantly associated with an increased risk of ICF after pPCI. Moreover, PIV was a better indicator of ICF than were other inflammatory markers.

No-reflow phenomenon in stroke patients: A systematic literature review and meta-analysis of clinical data

BACKGROUND

The no-reflow phenomenon refers to the absence of microvascular reperfusion despite macrovascular reperfusion.

AIM

The aim of this analysis was to summarize the available clinical evidence on no-reflow in patients with acute ischemic stroke.

METHODS

A systematic literature review and a meta-analysis of clinical data on definition, rates, and impact of the no-reflow phenomenon after reperfusion therapy was carried out. A predefined research strategy was formulated according to the Population, Intervention, Comparison, and Outcome (PICO) model and was used to screen for articles in PubMed, MEDLINE, and Embase up to 8 September 2022. Whenever possible, quantitative data were summarized using a random-effects model.

RESULTS

Thirteen studies with a total of 719 patients were included in the final analysis. Most studies (n = 10/13) used variations of the Thrombolysis in Cerebral Infarction scale to evaluate macrovascular reperfusion, whereas microvascular reperfusion and no-reflow were mostly assessed on perfusion maps (n = 9/13). In one-third of stroke patients with successful macrovascular reperfusion (29%, 95% confidence interval (CI), 21-37%), the no-reflow phenomenon was observed. Pooled analysis showed that no-reflow was consistently associated with reduced rates of functional independence (odds ratio (OR), 0.21, 95% CI, 0.15-0.31).

CONCLUSION

The definition of no-reflow varied substantially across studies, but it appears to be a common phenomenon. Some of the no-reflow cases may simply represent remaining vessel occlusions, and it remains unclear whether no-reflow is an epiphenomenon of the infarcted parenchyma or causes infarction. Future studies should focus on standardizing the definition of no-reflow with more consistent definitions of successful macrovascular reperfusion and experimental set-ups that could detect the causality of the observed findings.

Secondary rotational atherectomy is associated with reduced occurrence of prolonged ST-segment elevation following ablation

Elevation of the ST segment after percutaneous coronary intervention (PCI) using rotational atherectomy (RA) for severely calcified lesions often persists after disappearance of the slow-flow phenomenon on angiography. We investigated clinical factors relevant to prolonged ST-segment elevation following RA among 152 patients with stable angina undergoing elective PCI. PCI procedures were divided into two strategies, RA without (primary RA strategy) or with (secondary RA strategy) balloon dilatation before RA. Incidence of prolonged ST-segment elevation after disappearance of slow-flow phenomenon was higher in the 56 patients with primary RA strategy (13%) than in the 96 patients with secondary RA strategy (3%, p = 0.039). Univariate logistic regression analysis showed levels of low-density lipoprotein cholesterol (LDL-C) (odds ratio [OR] 0.95, 95% confidence interval [CI] 0.93-0.99; p = 0.013), levels of triglycerides (OR 0.97, 95%CI 0.94-0.99; p = 0.040), and secondary RA strategy (OR 0.23, 95% CI 0.05-0.85; p = 0.028) were inversely associated with occurrence of prolonged ST-segment elevation following ablation. However, hemodialysis, diabetes mellitus, left-ventricular ejection fraction, lesion length ≥ 20 mm, and burr size did not show significant associations. Multivariate logistic regression analysis modeling revealed that secondary RA strategy was significantly associated with the occurrence of prolonged ST-segment elevation (Model 1: OR 0.24, 95% CI 0.05-0.95, p = 0.042; Model 2: OR 0.17, 95% CI 0.03-0.68, p = 0.018; Model 3: OR 0.21, 95% CI 0.03-0.87, p = 0.041) even after adjusting for levels of LDL-C and triglycerides. Secondary RA strategy may be useful to reduce the occurrence of prolonged ST-segment elevation following RA.

Total ischemic time and age as predictors of PCI failure in STEMIs: A systematic review

BACKGROUND

When feasible, primary percutaneous coronary intervention (PCI) is the definitive intervention for ST-elevation myocardial infarction (STEMI). However, cardiac tissue reperfusion is not always achievable after opening the infarct-related artery. Studies have investigated associating factors and scoring for the "no-reflow" phenomenon. This paper aims to systematically establish the predictive values of total ischemic time and patient age as factors of coronary no-reflow in patients undergoing primary PCI.

METHODS

A systematic search was performed using EBSCOhost, including CINAHL Complete, Academic Search Premier, MEDLINE with Full Text, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews. Search results were compiled utilizing Zotero reference manager and exported to Covidence.org for screening, selection, and data extraction by two independent reviewers. The Newcastle-Ottawa Quality Assessment Scale for Cohort Studies was used to evaluate the eight selected studies.

RESULTS

The initial search resulted in 367 articles, with eight meeting the inclusion criteria with a total of 7060 participants. Our systematic review demonstrated that for patients older than 60 years, the odds of the no-reflow phenomenon increased 1.53- 2.53 times. Additionally, patients with increased total ischemic time had 1.147- 4.655 times the odds of no-reflow incidence.

CONCLUSIONS

Patients older than 60 years with a total ischemic time >4-6 h are at higher risk of PCI failure due to the no-reflow phenomenon. Therefore, new guidelines and more research to prevent and treat this physiologic occurrence are essential to improve coronary reperfusion after primary PCI.

An unusual no-reflow phenomenon due to neointimal tissue embolization during drug eluting balloon intervention in stent restenosis: A case report

Acute coronary syndrome is one of the leading causes of death worldwide. Percutaneous coronary intervention (PCI), along with various devices, have been technically developed to dramatically improve mortality risk in patients with acute myocardial infarction. However, no-reflow phenomenon still remains a problematic complication during a PCI, even in the era of drug eluting stents. There are various hypotheses and mechanisms for no-reflow phenomenon, but none have been confirmed. Treatment for no-reflow phenomenon also depends on various underlying conditions, but have not yet shown effective improvement. We presented a case of no-reflow phenomenon caused by an unusual cause.

Techniques to Treat Slow-Flow/No-Reflow During Primary Percutaneous Coronary Intervention

OBJECTIVE

The aim of this study was to compare TIMI flow after administering intracoronary (IC) medications through various routes for the treatment of slow flow/no-reflow during primary PCI.

METHODS

Two independent parallel cohorts of the patients who underwent primary PCI for STEMI and developed slow/no-reflow were recruited. Selection of cohort was based on the route of administration of IC medications as proximal or distal. Post administration TIMI follow was compared between the two cohorts.

RESULTS

A total of 100 patients were included in both, proximal and distal, cohort. Distribution of angiographic, clinical and demographic characteristics was not significant between the two cohorts except prevalence of hypertension, and diabetes mellitus. Frequency of hypertension, and diabetes mellitus were 45 % vs.70 %; p < 0.001 and 28 % vs. 44 %; p = 0.018 among patients in distal and proximal cohort respectively. Final TIMI III flow was achieved in significantly higher number of patients in distal cohort with the frequency of 88 % vs. 76 %; p = 0.027 as compared to proximal cohort.

CONCLUSION

Administration of IC medication via distal route is observed to be more effective for the treatment of slow flow/no-reflow during primary PCI. Distal route via export catheter or perforated balloon technique should be preferred wherever feasible.

The Impact of Kidney Function on the Slow-Flow/No-Reflow Phenomenon in Patients Treated with Primary Percutaneous Coronary Intervention: Registry Analysis

OBJECTIVE

The objective of this study is to analyze the impact of declining kidney function on the occurrence of the slow-flow/no-reflow phenomenon in patients with ST-elevation myocardial infarction (STEMI) treated with primary PCI (pPCI), as well as the analysis of the prognostic impact of the slow-flow/no-reflow phenomenon on short- and long-term mortality in these patients.

METHODS

We analyzed 3,115 consecutive patients. A value of the glomerular filtration rate (eGFR) at the time of admission of eGFR <90 ml/min/m2 was considered a low baseline eGFR. The follow-up period was 8 years.

RESULTS

The slow-flow/no-reflow phenomenon through the IRA was registered in 146 (4.7%) patients. Estimated GFR of <90 ml/min/m2 was an independent predictor for the occurrence of the slow-flow/no-reflow phenomenon (OR 2.91, 95% CI 1.25-3.95, p < 0.001), and the risk for the occurrence of the slow-flow/no-reflow phenomenon increased with the decline of the kidney function: eGFR 60-89 ml/min/m2: OR 1.94 (95% CI 1.22-3.07, p = 0.005), eGFR 45-59 ml/min/m2: OR 2.55 (95% CI 1.55-4.94, p < 0.001), eGFR 30-44 ml/min/m2: OR 2.77 (95% CI 1.43-5.25, p < 0.001), eGFR 15-29 ml/min/m2: OR 5.84 (95% CI 2.84-8.01, p < 0.001). The slow-flow/no-reflow phenomenon was a strong independent predictor of short- and long-term all-cause mortality: 30-day mortality (HR 2.62, 95% CI 1.78-3.57, p < 0.001) and 8-year mortality (HR 2.09, 95% CI 1.49-2.09, p < 0.001).

CONCLUSION

Reduced baseline kidney function was an independent predictor for the occurrence of the slow-flow/no-reflow phenomenon, and its prognostic impact started with the mildest decrease in eGFR (below 90 ml/min/m2) and increased with its further decline. The slow-flow/no-reflow phenomenon was a strong independent predictor of mortality in the short- and long-term follow-up of the analyzed patients.

Using an Artificial Neural Network to Predict Coronary Microvascular Obstruction (No-Reflow Phenomenon) during Percutaneous Coronary Interventions in Patients with Myocardial Infarction

The aim of the study was to develop, evaluate, and validate an artificial neural network to predict coronary microvascular obstruction (CMVO) during percutaneous coronary interventions (PCI) in patients with myocardial infarctions (MI) based on the parameters, which are routinely available in an operating room when choosing a surgical approach.

Effect of GP IIb/IIIa inhibitor duration on the clinical prognosis of primary percutaneous coronary intervention in ST-segment elevation myocardial infarction with no-/slow-reflow phenomenon

BACKGROUND

In patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI) accompanied by the no-/slow-reflow phenomenon, the maintenance duration of GP IIb/IIIa inhibitor (GPI) is controversial. We compare the efficacy and safety of short- and long-term GPI infusion in STEMI patients with the no-/slow-reflow phenomenon.

METHODS

From June 2016 to December 2019, we continuously included patients with on-set STEMI who underwent pPCI, accompanied by the no-/slow-reflow, during interventional procedures at Guangdong Provincial People's Hospital and Zhuhai Golden Bay Hospital. The hemorrhage events, heart function, and major adverse cardiovascular events (MACE) were compared between < 24 h and ≥ 24 h GPI duration groups. The Kaplan-Meier curve was used to estimate the 1-year MACE-free survival at different GPI utility times.

RESULTS

In total, 127 patients were divided into two groups based on the duration of tirofiban use (less and more than 24 h). There was no significant difference between two groups in terms of baseline characteristics, plaque condition, and coronary physiological function. The two groups showed similar in-hospital MACE (1 [1.85%] vs. 4 [5.48%], p = 0.394) and 1-year MACE-free survival (log-rank test p = 0.9085). The 1-year MACE remained consistent between the two groups in all subgroups of different risk factors of no-/slow-reflow. There was no significant difference in heart function and in-hospital hemorrhage events (3.7% vs. 1.37%, p = 0.179).

CONCLUSION

In the real world, prolonging the duration of GPI may not significantly improve the clinical outcome in patients with STEMI with no-/slow-reflow.

Comparison of the Outcomes between Coronary No-Reflow and Slow-Flow Phenomenon in Non-STEMI Patients

BACKGROUND

Coronary slow-flow phenomenon (CSFP) and coronary no-reflow phenomenon (CNP) are associated with increased risk of major cardiovascular adverse events (MACE).

OBJECTIVES

This study aimed to evaluate and compare the one-year clinical follow-up outcomes among patients with CNP and CSFP who underwent percutaneous coronary interventions (PCI) in non-ST elevation myocardial infarction (NSTEMI).

METHODS

This study included a total of 858 patients who were diagnosed with NSTEMI and underwent PCI within 24 h of symptom onset. The patients were divided into two groups, the CSFP group (n=221) and the CNP group (n=25), regarding the angiographic characteristics of thrombolysis in myocardial infarction (TIMI) flow of the infarct-related artery. Patients were followed for one-year. A p-value of <0.05 was considered significant.

RESULTS

CNP was observed in 2.91%, and CSFP was observed in 25.75% of the patients. Clinical endpoints analyzed that stroke was significantly higher in the CNP group than in the CSFP group (6 (24%) vs. 6 (2.70%), p<0.001) and MACE was significantly higher in the CNP group than in the CSFP group (11 (44%) vs. 51 (23.10%), p=0.022). Forward conditional logistic regression analysis demonstrated that body mass index (BMI) (OR=1.11, 95%CI: 1.00-1.24, p=0.038) and baseline heart rate (HR) (OR=0.923, 95%CI: 0.88-0.96, p<0.001) were the independent predictors of CNP in NSTEMI.

CONCLUSION

CNP patients have worse clinical outcomes and a higher risk of stroke compared with CSFP patients in NSTEMI. (Arq Bras Cardiol. 2021; 116(5):856-864).

Prophylactically injection of Nicorandil to reduce no-reflow phenomenon during PCI in acute STEMI patients: Protocol of a double-blinded, randomized, placebo-controlled trial

INTRODUCTION

An acute ST-elevation myocardial infarction (STEMI) is a very serious type of heart attack and a profoundly life-threatening medical emergency, and percutaneous coronary intervention (PCI) is the preferred strategy. However, in patients undergoing primary PCI, 30% to 40% may suffer the no-reflow phenomenon (NRP), and it could expand the myocardial infarction area and accompanied with high rehospitalization rate and fatality rate. In this study, we try to conduct a double blinded, randomized, placebo-controlled trial to observe whether the prophylactically intracoronary administration of Nicorandil could reduce the occurrence of NRP in STEMI patients undergoing PCI.

METHODS

Simple randomization in a 1:1 ratio will be made in blocks of variable size according to a random numbers generated by Excel 2010 to divide the patients to treatment group (Nicorandil) and control group (Saline). The outcomes are the occurrence of NRP, levels of interleukin-6 and HS-CRP, cTnT, and CK-MB before, and every 4 hours following PCI, and major adverse cardiovascular events at day 30. SPSS 23.0 (IBM, Chicago, IL) will be used, and P-value < .05 will be considered statistically significant.

CONCLUSIONS

The findings will determine the efficacy of prophylactically intracoronary administration of Nicorandil to reduce the occurrence of NRP during PCI in acute STEMI patients.

TRIAL REGISTRATION

OSF Registration number: DOI 10.17605/OSF.IO/QPF3V.

In-Hospital Peak Glycemia in Predicting No-Reflow Phenomenon in Diabetic Patients with STEMI Treated with Primary Percutaneous Coronary Intervention

Although percutaneous coronary intervention (PCI) significantly improves the prognosis for myocardial infarction, the no-reflow phenomenon is still the major adverse complication of PCI leading to increased mortality, especially for the patients with ST-segment elevation myocardial infarction (STEMI) combined with diabetes. To reduce the occurrence of no-reflow, prognostic factors must be identified for no-reflow phenomenon before PCI. A total of 262 participants with acute STEMI and diabetes were recruited into our cardiovascular center and underwent primary PCI for the analyses of prognostic factors of no-reflow. The patients were divided into two groups according to thrombolysis in myocardial infarction (TIMI): the normal flow and no-reflow groups, and related factors were analyzed with different statistical methods. In the present investigation, the in-hospital peak glycemia was significantly higher in the no-reflow group than the normal flow group, while more narrowed vessels, higher level of initial TIMI flow, were observed in the patients of the no-reflow group. A multivariate logistic regression analysis further demonstrated that peak glycemia was an independent predictor for no-reflow in the diabetic patients with STEMI. Our data indicated the importance of the proper control of glucose before PCI for the diabetic patients with STEMI before PCI to reduce the occurrence of the no-reflow after operation.

MicroRNA-208a: a Good Diagnostic Marker and a Predictor of no-Reflow in STEMI Patients Undergoing Primary Percutaneuos Coronary Intervention

MicroRNA-208a is a cardiac specific oligo-nucleotide. We aimed at investigating the ability of microRNA-208a to diagnose myocardial infarction and predict the outcome of primary percutaneuos coronary angiography (PCI). Patients (n = 75) presented by chest pain were recruited into two groups. Group 1 (n = 40) had ST elevation myocardial infarction (STEMI) and underwent primary PCI: 21 patients had sufficient reperfusion and 19 had no-reflow. Group 2 (n = 35) had negative cardiac troponins (cTns). Plasma microRNA-208a expression was assessed using quantitative polymerase chain reaction and patients were followed for occurrence of in-hospital major adverse cardiac events (MACE). MicroRNA-208a could diagnose of MI (AUC of 0.926). After primary PCI, it was superior to cTnT in prediction of no-reflow (AUC difference of 0.231, P = 0.0233) and MACE (AUC difference of 0.367, P = 0.0053). Accordingly, circulating levels of miR-208a can be used as a diagnostic marker of MI and a predictor of no-reflow and in-hospital MACE. Graphical abstract Receiver operating curve analysis of no-reflow prediction of miRNA208a, CK-MB and hs-Troponin T. MicroRNA-208a shows significantly higher prediction of no-reflow as compared to routine cardiac biomarkers.

Comparative Significance of Invasive Measures of Microvascular Injury in Acute Myocardial Infarction

BACKGROUND

The resistive reserve ratio (RRR) expresses the ratio between basal and hyperemic microvascular resistance. RRR measures the vasodilatory capacity of the microcirculation. We compared RRR, index of microcirculatory resistance (IMR), and coronary flow reserve (CFR) for predicting microvascular obstruction (MVO), myocardial hemorrhage, infarct size, and clinical outcomes, after ST-segment-elevation myocardial infarction.

METHODS

In the T-TIME trial (Trial of Low-Dose Adjunctive Alteplase During Primary PCI), 440 patients with acute ST-segment-elevation myocardial infarction from 11 UK hospitals were prospectively enrolled. In a subset of 144 patients, IMR, CFR, and RRR were measured post-primary percutaneous coronary intervention. MVO extent (% left ventricular mass) was determined by cardiovascular magnetic resonance imaging at 2 to 7 days. Infarct size was determined at 3 months. One-year major adverse cardiac events, heart failure hospitalizations, and all-cause death/heart failure hospitalizations were assessed.

RESULTS

In these 144 patients (mean age, 59±11 years, 80% male), median IMR was 29.5 (interquartile range: 17.0-55.0), CFR was 1.4 (1.1-2.0), and RRR was 1.7 (1.3-2.3). MVO occurred in 41% of patients. IMR>40 was multivariably associated with more MVO (coefficient, 0.53 [95% CI, 0.05-1.02]; P=0.031), myocardial hemorrhage presence (odds ratio [OR], 3.20 [95% CI, 1.25-8.24]; P=0.016), and infarct size (coefficient, 5.05 [95% CI, 0.84-9.26]; P=0.019), independently of CFR≤2.0, RRR≤1.7, myocardial perfusion grade≤1, and Thrombolysis in Myocardial Infarction frame count. RRR was multivariably associated with MVO extent (coefficient, -0.60 [95% CI, -0.97 to -0.23]; P=0.002), myocardial hemorrhage presence (OR, 0.34 [95% CI, 0.15-0.75]; P=0.008), and infarct size (coefficient, -3.41 [95% CI, -6.76 to -0.06]; P=0.046). IMR>40 was associated with heart failure hospitalization (OR, 5.34 [95% CI, 1.80-15.81] P=0.002), major adverse cardiac events (OR, 4.46 [95% CI, 1.70-11.70] P=0.002), and all-cause death/ heart failure hospitalization (OR, 4.08 [95% CI, 1.55-10.79] P=0.005). RRR was associated with heart failure hospitalization (OR, 0.44 [95% CI, 0.19-0.99] P=0.047). CFR was not associated with infarct characteristics or clinical outcomes.

CONCLUSIONS

In acute ST-segment-elevationl infarction, IMR and RRR, but not CFR, were associated with MVO, myocardial hemorrhage, infarct size, and clinical outcomes. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02257294.

Pathophysiology and diagnosis of coronary microvascular dysfunction in ST-elevation myocardial infarction

Early mechanical reperfusion of the epicardial coronary artery by primary percutaneous coronary intervention (PCI) is the guideline-recommended treatment for ST-elevation myocardial infarction (STEMI). Successful restoration of epicardial coronary blood flow can be achieved in over 95% of PCI procedures. However, despite angiographically complete epicardial coronary artery patency, in about half of the patients perfusion to the distal coronary microvasculature is not fully restored, which is associated with increased morbidity and mortality. The exact pathophysiological mechanism of post-ischaemic coronary microvascular dysfunction (CMD) is still debated. Therefore, the current review discusses invasive and non-invasive techniques for the diagnosis and quantification of CMD in STEMI in the clinical setting as well as results from experimental in vitro and in vivo models focusing on ischaemic-, reperfusion-, and inflammatory damage to the coronary microvascular endothelial cells. Finally, we discuss future opportunities to prevent or treat CMD in STEMI patients.

No-Reflow Complicating Chronic Total Occlusion Coronary Revascularization

OBJECTIVES

To assess the incidence of no-reflow in patients undergoing chronic total occlusion (CTO) percutaneous coronary intervention (PCI), analyze possible causes and differential diagnoses, and identify useful management approaches.

METHODS

In this multicenter observational study, all CTO-PCIs performed between January 2018 and April 2019 were reviewed to collect no-reflow complications, defined as Thrombolysis in Myocardial Infarction (TIMI) flow ≤1 in a patent epicardial artery. Patient clinical, anatomical, and procedural characteristics were analyzed.

RESULTS

Out of 461 PCIs, two (0.43%) were complicated by no-reflow. In 1 case, PCI was performed on a long segment of the right coronary artery, after use of a dissection-re-entry technique by knuckle wiring. In the second patient, no-reflow developed after proximal left anterior descending coronary artery stenting, with a short subintimal tracking. Intravascular ultrasound was used to exclude complications in the epicardial vessel in both cases. Distal embolization seems the most plausible cause, and intracoronary adenosine effectively improved flow. Both patients had a type 4a myocardial infarction, asymptomatic in the first case, and associated with chest pain, electrocardiographic changes, and new regional wall-motion abnormality at echocardiography in the second case.

CONCLUSIONS

No-reflow in CTO recanalization is rare, but associated with a high risk of periprocedural myocardial infarction, with incomplete protection from ischemia offered by the pre-existing collateral network.

The predictors of no reflow phenomenon after percutaneous coronary intervention in patients with ST elevation myocardial infarction: A meta-analysis

OBJECTIVE

To investigate the no reflow risk factors after percutaneous coronary intervention in ST elevation myocardial infarction patients.

METHOD

Sample size, mean±standard deviation (SD) or frequencies (percent) of normal and no reflow groups were extracted from each study.

RESULTS

Of 27 retrospective and prospective studies, we found that increasing risks of no reflow were associated with advanced age, male, family history of coronary artery disease, smoking, diabetes mellitus, hypertension, delayed reperfusion, killip class ≥2, elevated blood glucose, increased creatinine, elevated creatine kinase (CK), higher heart rate, decreased left ventricular ejection fraction (LVEF), collateral flow ≤1, longer lesion length, multivessel disease, reference luminal diameter, initial thrombolysis in myocardial infarction (TIMI) flow, and high thrombus burden. Moreover, initial TIMI flow ≤1 and high thrombus burden had the greater impact on no reflow (OR95%CI=3.83 [2.77-5.29], p<0.0001 and 3.69 [2.39-5.68], p<0.0001, respectively).

CONCLUSION

Our meta-analysis reveals that initial TIMI flow ≤1 and high thrombus burden are the most impacted no reflow risk factors.

Chronic obstructive pulmonary disease and periprocedural complications in patients undergoing percutaneous coronary interventions

Background

The relationship between chronic obstructive pulmonary disease (COPD) and periprocedural complications of percutaneous coronary interventions (PCIs) is influenced by several factors. We aimed to investigate the association between COPD, its complication type and rate in patients undergoing PCI.

Methods

Data were prospectively collected using the Polish Cardiovascular Intervention Society national registry (ORPKI) on all PCIs performed in Poland between January 2015 and December 2016. COPD was present in 5,594 of the 221,187 patients undergoing PCI. We assessed the frequency and predictors of periprocedural complications in PCI.

Results

Patients with COPD were elder individuals (70.3 ± 9.9 vs. 67 ± 10.8 years; p < 0.05). We noted 145 (2.6%) periprocedural complications in the COPD group and 4,121 (1.9%) in the non-COPD group (p < 0.001). The higher incidence of periprocedural complications in the COPD patients was mainly attributed to cardiac arrest (p = 0.001), myocardial infarctions (p = 0.002) and no-reflows (p < 0.001). COPD was not an independent predictor of all periprocedural complications. On the other hand, COPD was found to be an independent predictor of increased no-reflow risk (odds ratio [OR] 1.447, 95% CI 1.085–1.929; p = 0.01), and at the same time, of decreased risk of periprocedural allergic reactions (OR 0.117, 95% CI 0.016–0.837; p = 0.03).

Conclusions

In conclusion, periprocedural complications of PCIs are more frequent in patients with COPD. COPD is an independent positive predictor of no-reflow and a negative predictor of periprocedural allergic reactions.

The role of left ventricular deformation in the assessment of microvascular obstruction and intramyocardial haemorrhage

In the setting of acute ST-elevation myocardial infarction (STEMI), it remains unclear which strain parameter most strongly correlates with microvascular obstruction (MVO) or intramyocardial haemorrhage (IMH). We aimed to investigate the association of MVO, IMH and convalescent left ventricular (LV) remodelling with strain parameters measured with cardiovascular magnetic resonance (CMR). Forty-three patients with reperfused STEMI and 10 age and gender matched healthy controls underwent CMR within 3-days and at 3-months following reperfused STEMI. Cine, T2-weighted, T2*-imaging and late gadolinium enhancement (LGE) imaging were performed. Infarct size, MVO and IMH were quantified. Peak global longitudinal strain (GLS), global radial strain (GRS), global circumferential strain (GCS) and their strain rates were derived by feature tracking analysis of LV short-axis, 4-chamber and 2-chamber cines. All 43 patients and ten controls completed the baseline scan and 34 patients completed 3-month scans. In multivariate regression, GLS demonstrated the strongest association with MVO or IMH (beta = 0.53, p < 0.001). The optimal cut-off value for GLS was −13.7% for the detection of MVO or IMH (sensitivity 76% and specificity 77.8%). At follow up, 17% (n = 6) of patients had adverse LV remodeling (defined as an absolute increase of LV end-diastolic/end-systolic volumes >20%). Baseline GLS also demonstrated the strongest diagnostic performance in predicting adverse LV remodelling (AUC = 0.79; 95% CI 0.60–0.98; p = 0.03). Post-reperfused STEMI, baseline GLS was most closely associated with the presence of MVO or IMH. Baseline GLS was more strongly associated with adverse LV remodelling than other CMR parameters.

Limitation of Infarct Size and No-Reflow by Intracoronary Adenosine Depends Critically on Dose and Duration

OBJECTIVES

In the absence of effective clinical pharmacotherapy for prevention of reperfusion-mediated injury, this study re-evaluated the effects of intracoronary adenosine on infarct size and no-reflow in a porcine model of acute myocardial infarction using clinical bolus and experimental high-dose infusion regimens.

BACKGROUND

Despite the clear cardioprotective effects of adenosine, when administered prior to ischemia, studies on cardioprotection by adenosine when administered at reperfusion have yielded contradictory results in both pre-clinical and clinical settings.

METHODS

Swine (54 ± 1 kg) were subjected to a 45-min mid-left anterior descending artery occlusion followed by 2 h of reperfusion. In protocol A, an intracoronary bolus of 3 mg adenosine injected over 1 min (n = 5) or saline (n = 10) was administered at reperfusion. In protocol B, an intracoronary infusion of 50 μg/kg/min adenosine (n = 15) or saline (n = 21) was administered starting 5 min prior to reperfusion and continued throughout the 2-h reperfusion period.

RESULTS

In protocol A, area-at-risk, infarct size, and no-reflow were similar between groups. In protocol B, risk zones were similar, but administration of adenosine resulted in significant reductions in infarct size from 59 ± 3% of the area-at-risk in control swine to 46 ± 4% (p = 0.02), and no-reflow from 49 ± 6% of the infarct area to 26 ± 6% (p = 0.03).

CONCLUSIONS

During reperfusion, intracoronary adenosine can limit infarct size and no-reflow in a porcine model of acute myocardial infarction. However, protection was only observed when adenosine was administered via prolonged high-dose infusion, and not via short-acting bolus injection. These findings warrant reconsideration of adenosine as an adjuvant therapy during early reperfusion.

The Relationship between Interleukin-6 Promotor Polymorphisms and Slow Coronary Flow Phenomenon

BACKGROUND

Several lines of evidence suggest that slow coronary flow (SCF) phenomenon seems to be an early form of atherosclerosis and low-grade inflammation plays a role in the development of SCF. Interleukin-6 (IL-6) is a pleiotropic cytokine, functions as a mediator of inflammatory response, and has both pro-inflammatory and anti-inflammatory properties. The aim of the present study is to investigate the relationship between IL-6 -634C/G polymorphism and SCF in Han Chinese.

METHODS

250 subjects who underwent coronary angiography and had normal coronary arteries of varying coronary flow rates without any atherosclerotic lesion were enrolled in this study. 41 patients who had thrombolysis in myocardial infarction frame counts (TFC) above the normal cutoffs were considered to have SCF and 209 subjects within normal limits served as normal coronary flow (NCF) group. The PCR-based restriction fragment length polymorphism (PCR-RFLP) technique was used to assess the genotypes.

RESULTS

The distribution of the IL-6 -634C/G genotypes (CC, CG, and GG) was 56.94%, 37.80%, and 5.26% in the NCF subjects, and 36.59%, 48.78%, and 14.63% in the SCF group, respectively (p = 0.0173). The frequency of the G allele in the SCF (39.02%) group was significantly higher than that in the NCF (24.16%) group (p = 0.0054). Compared with the CC genotype, the G allele carriers (CG + GG genotypes) had increased risk of SCF in both unadjusted and adjusted analyses. In SCF patients, the average serum IL-6 levels (pg/mL) in CG + GG genotype (4.78 ± 0.42) were statistically higher than in CC genotype (3.93 ± 0.36) (p = 0.0000).

CONCLUSIONS

Our data support that IL-6 -634C/G polymorphism is associated with SCF and the G allele has increased risk for SCF in Han Chinese.

No reflow phenomenon in percutaneous coronary interventions in ST-segment elevation myocardial infarction

Percutaneous coronary intervention (PCI) is effective in opening the infarct related artery and restoring thrombolysis in myocardial infarction flow 3 (TIMI-flow 3) in large majority of ST-elevation myocardial infarction (STEMI). However there remain a small but significant proportion of patients, who continue to manifest diminished myocardial reperfusion despite successful opening of the obstructed epicardial artery. This phenomenon is called no-reflow. Clinically it manifests with recurrence of chest pain and dyspnea and may progress to cardiogenic shock, cardiac arrest, serious arrhythmias and acute heart failure. No reflow is regarded as independent predictor of death or recurrent myocardial infarction. No reflow is a multi-factorial phenomenon. However micro embolization of atherothrombotic debris during PCI remains the principal mechanism responsible for microvascular obstruction. This review summarizes the pathogenesis, diagnostic methods and the results of various recent randomized trials and studies on the prevention and management of no-reflow.

HEMATOLOGICAL MARKERS OF THE NO-REFLOW PHENOMEN ON IN-PATIENTS UNDERGOING PRIMARY PERCUTANEOUS CORONARY INTERVENTION

The study aims to investigate hematological parameters of the no-reflow phenomenon (NRP) developed in patients underwent primary percutaneous coronary intervention (pPCI) due to diagnosis of ST elevation myocardial infarction (STEMI). The study sample consisted of a total of 90 patients, of which 44 patients who underwent pPCI and developed NRP without anemia and chronic renal failure (mean age was 64; 34 males and 10 females) were included in the experimental group, and the control group consisted of 46 patients with normal reperfusion flow (mean age was 58; 34 males and 12 females). In both groups, Red blood-cell Distribution Width (RDW), Mean Platelet Volume (MPV), plateletcrit (PCT), Platelet Distribution Width (PDW), and neutrophil count were observed. The demographic characteristics of both groups were similar, except the higher mean age of the experimental group (age; 64.0±12.6; 58.0±12.5). No correlation was found between development of no-reflow and incidence of risk factors such as hypertension, diabetes mellitus, dyslipidemia, smoking, family history and gender. In the no-reflow group, RDW level (16.2%±2.1; 14.2%±0.7, p<0.001), MPV level (7.9±1.2; 7.3±0.8, p<0.05), PDW level (18.1±1.2; 17.4±1.2, p<0.05), PCT level (0.2±0.06 vs 0.17±0.05) and neutrophil count (9.9±3.7; 7.1±3.3, p<0.001) was found to be higher than the control group. According to logistic regression analysis, RDW (OR; 23.4, <95% Cl 4.6-118.9, p<0.001), PDW (OR; 2.8, <95% Cl 1.2-6.4, p<0.05) and neutrophil count (OR; 1.4, Cl 1.1-1.9, p<0.05) were found to be the predictors of NRP development. Hemogram is a cheap and easy to apply test. In our study, a relationship between the NRP development and RDW, PDW, MPV, PCT, and neutrophil counts was found in patients who underwent pPCI. At the same time, RDW, PDW, and the neutrophil count were found to be predictors of no-reflow development.

The relationship between neutrophil counts on admission and angiographic no-reflow after primary percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction

BACKGROUND

The no-reflow phenomenon during primary percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction (STEMI) can lead to poor outcomes. Increased neutrophil counts have been associated with an increased risk of adverse clinical events after acute myocardial infarction (AMI). The aim of this study was to assess the relation between admission neutrophil counts and angiographic no-reflow after PPCI.

METHODS

A total of 217 patients with acute STEMI who underwent PPCI, were enrolled. The patients were divided into two groups: no-reflow and normal-reflow. The neutrophil counts and other laboratory parameters were measured on admission before PPCI.

RESULTS

There were 41 patients (18.9%) in the no-reflow group and 176 patients in the normal-reflow group. Patients with no-reflow were older (68.0 ± 11.7 years vs 60.7 ± 13.2 years, P = 0.019) and had significantly higher admission neutrophil counts (9.02 ± 3.97 × 109/L vs 7.57 ± 2.82 × 109/L, P = 0.007). Also, high-sensitivity C-reactive protein (hsCRP), white blood counts, monocyte counts were significantly higher while haemoglobin values were significantly lower in the no-reflow group. In multivariate analysis, neutrophil counts remained a strong independent predictor of angiographic no-reflow (odds ratio 1,200, 95% confidence interval 1.073-1.342, P = 0.001) together with age (odds ratio 1.041, 95% confidence interval 1.012-1.071, P = 0.005).

CONCLUSIONS

Neutrophil counts on admission and age were independent clinical predictors of no-reflow following primary PCI in patients with STEMI. Our findings suggest that admission neutrophil counts may be available for early risk stratification of no-reflow after primary PCI and might allow the improvement of strategies to prevent this phenomenon.

Intravascular ultrasound observation of the mechanism of no-reflow phenomenon in acute myocardial infarction

Objective

To study the mechanism of the no-reflow phenomenon using coronary angiography (CAG) and intravascular ultrasound (IVUS).

Methods

A total of 120 patients with acute myocardial infarction (AMI) who successfully underwent indwelling intracoronary stent placement by percutaneous coronary intervention (PCI). All patients underwent pre- and post-PCI CAG and pre-IVUS. No-reflow was defined as post-PCI thrombolysis in myocardial infarction (TIMI) grade 0, 1, or 2 flow in the absence of mechanical obstruction. Normal reflow was defined as TIMI grade 3 flow. The pre-operation reference vascular area, minimal luminal cross-sectional area, plaque cross-sectional area, lesion length, plaque volume and plaque traits were measured by IVUS.

Results

The no-reflow group was observed in 14 cases (11.6%) and normal blood-flow group in 106 cases (89.4%) based on CAG results. There was no statistically significant difference in the patients’ medical history, reference vascular area (no-flow vs. normal-flow; 15.5 ± 3.2 vs. 16.2 ± 3.3, p> 0.05) and lesion length (21.9 ± 5.1 vs. 19.5 ± 4.8, p> 0.05) between the two groups. No-reflow patients had a longer symptom onset to reperfusion time compared to normal blood-flow group [(6.6 ± 3.1) h vs (4.3 ± 2.7) h; p< 0.05] and higher incidence of TIMI flow grade< 3 (71.4% vs 49.0%, p< 0.05). By IVUS examination, the no-reflow group had a significantly increased coronary plaque area and plaque volume compared to normal blood-flow group [(13.7 ± 3.0) mm² vs (10.2 ± 2.9) mm²; (285.4 ± 99.8) mm³ vs (189.7 ± 86.4) mm³; p< 0.01]. The presence of IVUS-detected soft plaque (57.1% vs. 24.0%, p< 0.01), eccentric plaque (64.2% vs. 33.7%, p< 0.05), plaque rupture (50.0% vs. 21.2%, p< 0.01), and thrombosis (42.8% vs. 15.3%) were significantly more common in no-reflow group.

Conclusion

There was no obvious relationship between the coronary risk factors and no-reflow phenomenon. The symptom onset to reperfusion time, TIMI flow grade before stent deployment, plaque area, soft plaques, eccentric plaques, plaque rupture and thrombosis may be risk factors for the no-reflow phenomenon after PCI.

The clinical implications of balloon rupture during cardiovascular interventions

Balloon rupture is an infrequent complication of cardiac catheterization that can lead to vessel injury. We report 6 cases that highlight the potential consequences of balloon rupture, including perforation, dissection, balloon entrapment, and distal embolization, and discuss prevention and treatment strategies.

Effects of verapamil and adenosine in an adjunct to tirofiban on resolution and prognosis of noreflow phenomenon in patients with acute myocardial infarction

AIM

We aimed to investigate the effects of verapamil and adenosine in an adjunct to intravenous tirofiban on management and prognosis of no-reflow phenomenon during primary percutaneous coronary intervention (PPCI) and to compare their efficacies on reversing of no-reflow phenomenon and short and midterm survival.

METHODS

We included 46 patients with acute ST-segment elevation myocardial infarction (STEMI) and occurrence of no-reflow phenomenon after PPCI. All patients received intravenous tirofiban and then randomized into one of the following 3 groups: intracoronary adenosine (N.=16), intracoronary verapamil (N.=15) or placebo (N.=15).

RESULTS

Intracoronary verapamil therapy had significant effect in restoring impaired coronary blood flow by decreasing thrombolysis in myocardial infarction (TIMI) frame count from 73±44 to 52±48 (P=0.024). However, adenosine and serum physiologic administration were not found to be so effective in decreasing TIMI frame count (from 81±35 to 71±46, P=0.084; from 74±32 to 71±37, P=0.612, respectively). In-hospital and 6-month survival rates were similar among groups.

CONCLUSION

In conclusion, intracoronary verapamil restored the impaired coronary blood flow more effectively than adenosine or placebo. However, none of them has changed the clinical course in the first 6 months.

[Relation of admission neutrophil/lymphocyte ratio to angiographic no-reflow phenomenon in patients with ST-elevated myocardial infarction undergoing primary coronary intervention]

OBJECTIVE

To investigate the relationship of the neutrophil/lymphocyte ratio (NLR) on admission and angiographic no-reflow phenomenon in patients with ST-segment elevation myocardial infarction (STEMI) who had undergone primary percutaneous coronary intervention (PCI).

METHODS

232 patients who had undergone PCI between 2010 and 2013, were included and divided into two groups based upon the thrombolysis in myocardial infarction (TIMI) flow gradings. No-reflow was defined as post-PCI TIMI Grade 0, 1 and 2 flows (group I). Normal-flow was defined as TIMI 3 flow (group II). Receiver operating characteristic curve (ROC) analysis was used to identify the predictive effect of NLR on no-reflow phenomenon. Relationship of NLR and no-reflow was assessed by multivariate logistic regression. All statistical calculations and analyses were performed using SPSS 11.0.

RESULTS

NLR was significantly higher in group I (n = 45) compared with group II (n = 187) [4.1(2.4-6.5) vs. 2.4 (1.7-3.8), P = 0.001]. In ROC analysis, NLR>3.2 predicted no reflow with 80% sensitivity and 73% specificity. Patients with elevated NLR had a higher incidence of no-reflow phenomenon than those with non-elevated NLR (34.8% vs. 9.3%, P < 0.001). Also, NLR (>3.2) was an independent predictor of no-reflow development [odds ratio 3.70, 95% confidence interval(1.39-9.80), P = 0.009].

CONCLUSION

NLR was an independent predicator for no-reflow development in STEMI patients who had undergone PCI. This simple and low-cost parameter could provide useful information for the early risk evaluation on these patients.

[Coronary microvascular obstruction phenomenon after endovascular recanalization in patients with chronic coronary occlusions]

The article analyzed no-reflow phenomenon after endovascular recanalization for chronic coronary occlusion. An assessment of antegrade blood flow was made while performing the coronary angiography according to TIMI classification. The Rentrop scale was used for evaluation of retrograde blood flow. The results of investigation showed, that the frequency of occurrence of no-reflow phenomenon after endovascular recanalization in the case of chronic coronary occlusion wasn't higher than 5%. The onset of no-reflow phenomenon after endovascular recanalization in chronic coronary occlusion doesn't depend on the volume of retrograde collateral filling of distal coronary bloodstream. A postponed restoration of antegrade blood flow was possible in patients with previously manifested (Rentrop II-III) retrograde collateral filling of periphery.

[No-reflow phenomenon in the practice of an endovascular surgeon]

No-reflow phenomenon is a complication of percutaneous coronary intervention and is the absence of distal coronary bed filling. The main cause of this phenomenon is distal embolism of the coronary artery by atheromatous and thrombotic masses. The paper gives different classifications for evaluation of myocardial and coronary reperfusion. The use of aspiration catheters, glycoprotein IIb/IIIa receptor inhibitors and other drugs that affect prognosis in patients with this phenomenon is also touched upon.

The effect of microvascular obstruction and intramyocardial hemorrhage on contractile recovery in reperfused myocardial infarction: insights from cardiovascular magnetic resonance

BACKGROUND

Following acute myocardial infarction (AMI), microvascular obstruction (MO) and intramyocardial hemorrhage (IMH) adversely affect left ventricular remodeling and prognosis independently of infarct size. Whether this is due to infarct zone remodeling, changes in remote myocardium or other factors is unknown. We investigated the role of MO and IMH in recovery of contractility in infarct and remote myocardium.

METHODS

Thirty-nine patients underwent cardiovascular magnetic resonance (CMR) with T2-weighted and T2* imaging, late gadolinium enhancement (LGE) and myocardial tagging at 2, 7, 30 and 90 days following primary percutaneous coronary intervention for AMI. Circumferential strain in infarct and remote zones was stratified by presence of MO and IMH.

RESULTS

Overall, infarct zone strain recovered with time (p < 0.001). In the presence of MO with IMH and without IMH, epicardial strain recovered (p = 0.03, p < 0.01 respectively), but mid-myocardial or endocardial strain did not (mid-myocardium: p = 0.05, p = 0.12; endocardium: p = 0.27, p = 0.05, respectively). By day 90, infarcts with MO had more attenuated strain in all myocardial layers compared to infarcts without MO (p < 0.01); those with IMH were attenuated further (p < 0.01). Remote myocardial strain was similar across groups at all time-points (p > 0.2). Infarct transmural extent did not correlate with strain (p > 0.05 at each time point). In multivariable logistic regression, MO and IMH were the only significant independent predictors of attenuated 90-day infarct zone strain (p = 0.004, p = 0.011, respectively).

CONCLUSIONS

Strain improves within the infarct zone overall following reperfusion with or without MO or IMH. Mid-myocardial and endocardial infarct contractility is diminished in the presence of MO, and further in the presence of IMH. MO and IMH are greater independent predictors of infarct zone contractile recovery than infarct volume or transmural extent.

CMR of microvascular obstruction and hemorrhage in myocardial infarction

Microvascular obstruction (MO) or no-reflow phenomenon is an established complication of coronary reperfusion therapy for acute myocardial infarction. It is increasingly recognized as a poor prognostic indicator and marker of subsequent adverse LV remodeling. Although MO can be assessed using various imaging modalities including electrocardiography, myocardial contrast echocardiography, nuclear scintigraphy, and coronary angiography, evaluation by cardiovascular magnetic resonance (CMR) is particularly useful in enhancing its detection, diagnosis, and quantification, as well as following its subsequent effects on infarct evolution and healing. MO assessment has become a routine component of the CMR evaluation of acute myocardial infarction and will increasingly play a role in clinical trials of adjunctive reperfusion agents and strategies. This review will summarize the pathophysiology of MO, current CMR approaches to diagnosis, clinical implications, and future directions needed for improving our understanding of this common clinical problem.

Pathophysiology of coronary thrombus formation and adverse consequences of thrombus during PCI

Atherosclerosis is a systemic vascular pathology that is preceded by endothelial dysfunction. Vascular inflammation "fuels" atherosclerosis and creates the milieu for episodes of intravascular thromboses. Thrombotic events in the coronary vasculature may lead to asymptomatic progression of atherosclerosis or could manifest as acute coronary syndromes or even sudden cardiac death. Thrombus encountered in the setting of acute coronary syndromes has been correlated with acute complications during percutaneous coronary interventions such as no-reflow, acute coronary occlusion and long term complications such as stent thrombus. This article reviews the pathophysiology of coronary thrombogenesis and explores the complications associated with thrombus during coronary interventions.

Early statin treatment prior to primary PCI for acute myocardial infarction: REPERATOR, a randomized placebo-controlled pilot trial

OBJECTIVE

The aim of this pilot study was to determine whether early atorvastatin treatment will reduce left ventricle (LV) remodeling, infarct size, and improve microvascular perfusion.

BACKGROUND

In animal studies, early statin therapy reduces reperfusion injury after a percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI).

METHODS

Forty-two consecutive patients (82% male, mean age 61.2 ± 9.8) who underwent a primary PCI for a first ST-elevated AMI were randomized for pretreatment with atorvastatin 80 mg (n = 20) or placebo (n = 22) and continued with the same dosage daily for 1 week. All patients received atorvastatin 80 mg once daily 7 days after primary PCI. The LV function and infarct size were measured by magnetic resonance imaging within 1 day, at 1 week, and 3 months follow up. The primary endpoint was the end-systolic volume index (ESVI) at 3 months. Secondary endpoints were global LV function measurements, myocardial infarct size, biochemical cardiac markers, TIMI flow, and ST-T elevation resolution.

RESULTS

ESVI 3 months after AMI was 25.1 mL/m(2) in the atorvastatin arm and 25.0 mL/m(2) in the placebo arm (P = 0.74). The differences in change from baseline to 3 months follow up in global LV function and myocardial infarct size did not differ between both treatment arms. Furthermore, biochemical markers, TIMI flow, and ST-T elevation resolution did not differ between atorvastatin and placebo arm.

CONCLUSIONS

In this pilot study, pretreatment with atorvastatin in an acute myocardial infarction does not result in an improved cardiac function, microvascular perfusion, or decreased myocardial infarct size.

[Influencing factor analysis of no-reflow phenomenon after reperfusion in patients with chronic limb ischemia associated with acute thrombosis]

OBJECTIVE

To analyze the influencing factors of no-reflow phenomenon after reperfusion in patients with chronic limb ischemia associated with acute thrombosis.

METHODS

Between January 2009 and December 2010, 59 patients (67 limbs) with chronic limb ischemia associated with acute thrombosis were treated. According to whether the no-reflow phenomenon occurred or not, the patients were divided into no-reflow group (19 patients, 21 limbs) and reflow group (40 patients, 46 limbs). Logistic regression was used to analyze the roles of ischemia time, ischemia extent, smoking, hypertension, cardiovascular and cerebrovascular disease, diabetes, surgical procedure, platelet count, fibrinogen (FBG), prostaglandin 12 (PGI2), and thromboxane A2 (TXA2) on no-reflow phenomenon after reperfusion.

RESULTS

The results of the logistic regression analysis indicated that ischemia time (OR =7.196; 95%CI: 1.679-27.960), ischemia extent (OR = 5.116; 95% CI: 1.399-109.338), smoking (OR = 6.893; 95% CI: 3.704-2 291.003), diabetes (OR = 3.864; 95% CI: 1.009-421.702), PGI2 (OR = 7.985; 95% CI: 1.001-1.043), and TXA2 (OR = 7.643; 95% CI: 1.011-1.065) were the high risk factors of no-reflow phenomenon. The levels of TXA2 and FBG in no-reflow group were significantly increased and the level of PGI2 was decreased, showing significant differences when compared with the reflow group (P < 0.05). However, no significant difference was found in the platelet count between 2 groups (P > 0.05).

CONCLUSION

Ischemia extent and ischemia time are the main influencing factors of no-reflow phenomenon after reperfusion in patients with chronic limb ischemia associated with acute thrombosis, and the patients combined with smoking or diabetes are high risk population of the no-reflow phenomenon. Postoperative patients with no-reflow phenomenon are at a hypercoagulable state in vivo, in which prostacyclin plays an important role.

[Predictors of the no-reflow phenomenon after primary percutaneous coronary intervention for acute myocardial infarction]

OBJECTIVE

To identify the risk factors for no-reflow (NR) phenomenon after primary percutaneous coronary intervention (PCI) in patients with acute myocardial infarction.

METHODS

A total of 843 patients with AMI underwent primary PCI within 12 h following onset of the ischemic symptoms. According to TIMI flow grade and myocardial blush grade, the patients were divided into reflow group and NR group after primary PCI, and the clinical data, angiography findings and surgical data were compared to analyze the factors contributing to NR.

RESULTS

NR occurred in 15.9% of the AMI patients after primary PCI. Univariate analysis showed that previous myocardial infarction, Killip classes of MI, time to reperfusion, IABP use before PCI, TIMI flow grade before primary PCI, long target lesion, pre-PCI thrombus score and method of reperfusion were correlated to NR (P<0.05 ). Multiple logistic analysis identified the time to reperfusion (OR=1.60; 95% CI: 1.02-2.73), TIMI flow grade before primary PCI (OR=1.1; 95% CI: 1.04-1.16), long target lesion (OR=1.40; 95% CI: 1.19-1.69), and pre-PCI thrombus score (OR=2.02; 95% CI: 1.47-2.76) as the independent predictors of NR after primary PCI.

CONCLUSION

The time to reperfusion, TIMI flow grade before primary PCI, long target lesion, and pre-PCI thrombus score are independent predictors of NR after primary PCI for AMI.