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.

Could Pan-Immune-Inflammation Value be a Marker for the Diagnosis of Coronary Slow Flow Phenomenon?

Inflammation plays a key role in the pathogenesis of the coronary slow flow phenomenon (CSFP). The newly developed inflammatory marker, pan-immune-inflammation value (PIV), is associated with adverse cardiovascular events. This study investigated the predictive value of PIV for diagnosing CSFP in comparison to other inflammation-based markers. A total of 214 patients, 109 in the CSFP group and 105 in the normal coronary flow (NCF) group, were retrospectively included in the study. Coronary flow was calculated using the Thrombolysis in Myocardial Infarction frame count method. In addition to PIV, other inflammatory markers such as neutrophil-lymphocyte ratio, platelet-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII) were calculated for the patients. The average age of patients was 50.3 ± 8.4, with a male ratio of 55.1%. Compared to the NCF group, patients in the CSFP group had higher levels of hyperlipidemia, glucose, triglyceride, NLR, PLR, SII, and PIV, while their high-density lipoprotein cholesterol (HDL-C), was lower (p < 0.05). Logistic regression analysis demonstrated that HDL-C, glucose, triglyceride, and PIV were independent predictor factors for CSFP (p < 0.05). PIV is a strong and independent predictor factor for CSFP and superior in predicting CSFP compared to other inflammatory markers.

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.

FGF-21: a novel biomarker predicting no-reflow in ST-segment elevation myocardial infarction

OBJECTIVE

Primary percutaneous coronary intervention (pPCI) is the most effective reperfusion therapy in the treatment of ST-elevation myocardial infarction (STEMI). Although the infarct-related artery of STEMI patients is effectively revascularized during pPCI, effective reperfusion in the myocardial tissue may not be achieved. This condition is called the no-reflow (NR) phenomenon. FGF-21 is a circulating hormone-like molecule primarily secreted by the liver and has been proven to be the main metabolic regulator of glucolipid metabolism and insulin sensitivity. The aim of this study was to investigate the predictive effect of FGF-21 on the development of the NR phenomenon in STEMI patients undergoing pPCI.

PATIENTS AND METHODS

This study included 91 patients with acute STEMI who underwent pPCI and 45 healthy participants. Patients with acute STEMI were split into two groups: 46 patients in the NR phenomenon group and 45 patients in the non-NR phenomenon group. Serum levels of FGF-21 were measured in all study groups.

RESULTS

Serum FGF-21, white blood cell count, and high-sensitivity C-reactive protein (hs-CRP) values were considerably different amongst the groups (p = 0.001, p = 0.001, and p = 0.003, respectively). In comparison to patients without NR and the control group, STEMI patients with NR had considerably higher FGF-21 levels. In addition, the FGF-21 level of STEMI patients without NR was significantly higher than that of the control group. In multivariate logistic regression analysis, hs-CRP [odds ratio (OR) 2.106% 95% confidence interval (CI) (0.002-0.069) p = 0.038], age [OR 2.147; 95% (CI) (0.001-0.015); p = 0.0035], and serum FGF-21 levels [OR 4.644; 95% CI (0.003-0.006); p < 0.001] were independent predictors of NR formation. For FGF-21 ≥ 92.2 pg/Ml, 87% sensitivity and 88% specificity were found in predicting NR formation (area under the curve: 0.897, 95% CI: 0.841-0.954; p < 0.001).

CONCLUSIONS

Our study demonstrates a strong association between the NR phenomenon, a key indicator of poor prognosis in acute STEMI patients, and an elevated FGF-21 level. These findings indicate FGF-21 as a novel and potent predictor of NR development in STEMI patients.

The triglyceride-glucose index as a predictive marker for coronary slow flow phenomenon

OBJECTIVE

The triglyceride-glucose index (TyG) has been proposed as a marker of insulin resistance (IR) and has shown associations with cardiovascular diseases. This study aimed to investigate the relationship between the TyG and the coronary slow flow phenomenon (CSFP) and explore the index's potential as a predictor of this condition.

PATIENTS AND METHODS

A total of 187 patients who underwent coronary angiography were included; of these, 91 patients were diagnosed with CSFP, and 96 patients with normal coronary flow served as a control group. The TyG was calculated using fasting triglyceride and glucose levels.

RESULTS

The results showed that the TyG was significantly higher in the CSFP group compared with the control group (p < 0.001). Additionally, the TyG exhibited a moderate positive correlation with the thrombolysis-in-myocardial-infarction frame count in coronary arteries (p < 0.001). A multivariate logistic regression analysis revealed that the TyG, along with gender, ejection fraction, and uric acid, remained significant predictors of CSFP (p < 0.05).

CONCLUSIONS

This study's findings suggest that the TyG may serve as a useful marker for identifying individuals at risk of CSFP and provide insights into the potential role of IR in its pathophysiology.

The predictive value of the HALP score for no-reflow phenomenon and short-term mortality in patients with ST-elevation myocardial infarction

OBJECTIVE

ST-elevation myocardial infarction (STEMI) is a medical emergency demanding immediate intervention, and primary percutaneous coronary intervention (pPCI) is the standard of care for this condition. While PCI has proven highly effective, a subset of patients experience the devastating no-reflow phenomenon, and some face increased short-term mortality. The Hemoglobin, Albumin, Lymphocyte, and Platelet (HALP) score, a novel biomarker-based tool, has recently surfaced as an innovative predictor of these adverse outcomes. This study aims to investigate the groundbreaking findings that designate a low HALP score as a robust risk factor for no-reflow and short-term mortality in STEMI patients.

METHODS

1817 consecutive STEMI patients who underwent pPCI were included in this retrospective study, and the patients were divided into two groups according to whether no-reflow developed or not, and the HALP scores of the groups were compared. In addition, short-term mortality was compared between the study groups according to their HALP score values. The predictive ability of the HALP score for no-reflow was evaluated using a receiver operating characteristic curve.

RESULTS

No-reflow developed in 198 (10.1%) of the patients included in the study. HALP score value was found to be significantly lower in the no-reflow group (27 ± 13 vs 47 ± 24, p < 0.001). After multivariable adjustment, the HALP score was an independent predictor of no-reflow (OR, 0.923, 95% CI, 0.910-0.935, p < 0.001). Furthermore, the HALP score showed good discrimination for no-reflow (AUC, 0.771, 95% CI, 0.737-0.805, p < 0.001). In addition, HALP score was determined to be an independent predictor for short-term mortality (HR, 0.955, 95% CI, 0.945-0.966, p < 0.001).

CONCLUSIONS

HALP score can independently predict the development of no-reflow and short-term mortality in STEMI patients undergoing pPCI.

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.

A retrospective study: Association of C-reactive protein and uric acid to albumin ratio with the no-reflow phenomenon in patients with ST elevation myocardial infarction

BACKGROUND

The no-reflow phenomenon increases mortality and morbidity in patients with ST-segment elevation myocardial infarction (STEMI). Inflammation, endothelial dysfunction, and oxidative stress play important role in its pathophysiology. We aim to evaluate the relationship between the no-reflow phenomenon and C-reactive protein (CRP) and uric acid (UA) to albumin ratio (CUAR), which is a new marker indicating all these pathophysiological mechanisms.

METHODS AND RESULTS

Study population were divided into two groups as no-reflow and reflow; according to the post-procedural thrombolysis in myocardial infarction flows and myocardial blush grade. A1:4 propensity score matching was performed.CUAR was calculated by using the following formula: log10 (CRP x UA /Albumin). CUAR levels were significantly higher in patients with no-reflow than in those with reflow (P < 0.001). CUAR levels above 1.28 predicted no-reflow with higher sensitivity of 74% and specificity of 71% than all including CRP, UA and albumin (AUC = 0.80 [95%CI: 0.76-0.83], P < 0.001). In multivariate logistic regression analysis, CUAR levels above 1.28 (OR: 4.43 [3.04-6.46], 95% CI; P < 0.001) wereindependently associated with no-reflow phenomenon.

CONCLUSION

Our results showed that CUAR could be a basic and available marker to predict no-reflow in patients with STEMI who underwent primary percutaneous coronary intervention.

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.

Predicting no-reflow phenomenon prior to primary percutaneous coronary intervention using a novel probability risk score derived from clinical and angiographic parameters

OBJECTIVE

We aimed to create a clinically usable probability risk score for prediction of no-reflow (NRF) phenomenon prior to primary percutaneous coronary intervention (PPCI).

PATIENTS AND METHODS

This single-center and retrospective study included 1254 patients with acute ST-segment elevation myocardial infarction (STEMI) who underwent PPCI. Patients were randomly assigned into two groups in the ratio 2:1, the derivation dataset (n=840) and validation dataset (n=414). Independent predictors of NRF were identified and combined to create a prediction model using univariate and multivariate regression analysis in the derivation dataset. The risk score was tested and validated by calculating area under the receiver operating characteristic (ROC) curves in the derivation and validation datasets, respectively.

RESULTS

Five significant, independent predictors of NRF were identified: age ≥ 65 years (odds ratio [OR]: 2.473, 95% confidence interval [CI]: 0.389-1.484, p < 0.01), heart rate ≥ 89 bpm (odds ratio [OR]: 1.622, 95% confidence interval [CI]: 0.024-0.945, p < 0.05), Killip class ≥ II (odds ratio [OR]: 1.914, 95% confidence interval [CI]: 0.024-1.306, p < 0.01), total ischemic time ≥ 268 min (odds ratio [OR]: 2.652, 95% confidence interval [CI]: 0.493-1.565, p < 0.01), and thrombus burden G≥4 (odds ratio [OR]: 8.351, 95% confidence interval [CI]: 0.344-15.901, p < 0.01). The risk score was created combining these predictors with assigned points. The overall score ranged from 0 to 17 points. The optimal cutoff value of the risk score was 11 points (area under curve [AUC]: 0.772, 95% confidence interval [CI]: 0.729-0.815, sensitivity 71.21%, specificity 70.34%, positive predictive value 30.92%, negative predictive value 92.91%, p < 0.001). The ROC curve for the validation group showed good discriminant power.

CONCLUSIONS

We developed a novel risk score based on five clinical and angiographic parameters, which might be a useful clinical tool for prediction of NRF in STEMI patients prior to PPCI with an acceptable accuracy.

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.

No-reflow phenomenon during percutaneous coronary intervention in a patient with polycythemia vera: A case report

RATIONALE

Acute myocardial infarction is the leading cause of mortality and morbidity in a patient with polycythemia vera (PV). However, the benefit of various percutaneous coronary intervention (PCI) technique on the patient with PV is relatively unexplored.

PATIENT CONCERN

A 46-year-old woman presented to the primary hospital complained about new-onset typical chest pain. Echocardiography examination showed inferior ST-elevation myocardial infarction (STEMIs) and increased cardiac markers. Complete blood count showed elevated hemoglobin, white blood cell, and platelet.

DIAGNOSIS

Coronary angiography revealed simultaneous total occlusion at proximal right coronary artery (RCA) and also at proximal left anterior descending (LAD) artery. Elevated hemoglobin and hematocrit with JAK2 mutation establish the diagnosis of PV.

INTERVENTIONS

We performed multi-vessel primary PCI by using direct stenting in RCA and aspiration thrombectomy in LAD after failed with balloon dilatation and direct stenting method. This procedure resulted in thrombolysis in myocardial infarction (TIMI)-3 flow in both coronary arteries. However, the no-reflow phenomenon occurred in the LAD, followed by ventricular fibrillation. After several attempts of resuscitation, thrombus aspiration, and low-dose intracoronary thrombolysis, the patient was returned to spontaneous circulation. The patient then received dual antiplatelet and cytoreductive therapy.

OUTCOMES

The patient clinical condition and laboratory finding were improved, and the patient was discharged on the 7th day after PCI.

LESSONS

Cardiologist should be aware of the no-reflow phenomenon risk in the patient with PV and STEMI. Direct stenting, intracoronary thrombectomy, and thrombolysis are preferable instead of balloon dilatation for PCI technique in this patient.

CHA2DS2-VASc Score as an Independent Predictor of Suboptimal Reperfusion and Short-Term Mortality after Primary PCI in Patients with Acute ST Segment Elevation Myocardial Infarction

Background and objectives: We aimed to demonstrate the clinical utility of CHA2DS2-VASc score in risk assessment of patients with STEMI regarding adverse clinical outcomes particularly no-reflow phenomenon. Materials and Methods: We designed a retrospective cohort study using the data of Tehran Heart Center registry for acute coronary syndrome. The study included 1331 consecutive patients with STEMI who underwent primary angioplasty. Patients were divided into two groups according to low and high CHA2DS2-VASc score. Angiographic results of reperfusion were inspected to evaluate the association of high CHA2DS2-VASc score and the likelihood of suboptimal TIMI flow. The secondary endpoint of the study was short-term in-hospital mortality of all cause. Results: The present study confirmed that CHA2DS2-VASc model enables us to determine the risk of no-reflow and all-cause in-hospital mortality independently. Odds ratios were 1.59 (1.30–2.25) and 1.60 (1.17–2.19), respectively. Moreover, BMI, high thrombus grade, and cardiogenic shock were predictors of failed reperfusion (odds were 1.07 (1.01–1.35), 1.59 (1.28–1.76), and 8.65 (3.76–24.46), respectively). We showed that using a cut off value of ≥ two in CHA2DS2-VASc model provides a sensitivity of 69.7% and specificity of 64.4% for discrimination of increased mortality hazards. Area under the curve: 0.72 with 95% CI (0.62–0.81). Conclusions: Calculation of CHA2DS2-VASc score applied as a simple risk stratification tool before primary PCI affords great predictive power. Furthermore, incremental values are obtained by using both CHA2DS2-VASc and no-reflow regarding mortality risk assessment.

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.

Clinical, demographic, risk factor and angiographic profile of coronary slow flow phenomenon: A single centre experience

Background

The coronary slow flow phenomenon (CSFP) is an angiographic finding characterized by delayed distal vessel opacification in the absence of significant epicardial coronary stenosis. Although it is well-known to interventional cardiologists for approximately four decades, the etiopathogenesis still remains unclear.

Aims and objectives

In this study, we aimed to determine the clinical, demographic, risk factor and angiographic profile of patients with CSFP.

Methods

Clinical, demographic, risk factor and angiographic profile were recorded in all consecutive patients who had undergone coronary angiography between September 2016 and March 2017 and showed features of CSFP and a control group who showed normal coronary flow (NCF). The CSFP was diagnosed on the basis of the corrected thrombolysis in myocardial infarction frame count.

Results

CSFP was significantly more prevalent in male patients. Among the traditional risk factors, there was significantly more prevalence of hypertension (31.25% versus 6.67%, p < 0.001), dyslipidemia (40% versus 7.5%, p < 0.001) and history of tobacco use (47.5% versus 10.0%, p < 0.001) in CSFP patients as compared to NCF patients. On multivariable regression analysis hypertension, dyslipidemia, history of smoking and tobacco chewing were found to have independent association with CSFP. Acute coronary syndrome (ACS) was the most common mode of presentation in CSFP patients.

Conclusion

CSFP was relatively common among patients who presented with ACS. Hypertension, dyslipidemia, smoking and tobacco chewing can be considered independent risk factors for this phenomenon. Therefore, CSFP should be considered as a pathological entity and not an entirely benign condition.

Experimental study of histological changes in vascular loops according to the duration of the postoperative period: Application in reconstructive microsurgery

OBJECTIVES

To analyze the histological changes observed in venous grafts subjected to arterial blood flow as a function of the duration of the postoperative period to optimize their use in free flap reconstructions.

METHOD

Twenty-five rats (7 females and 18 males) underwent surgery. Surgeries were performed on one animal per week. Five weeks after the first surgery, the same five animals were subjected to an additional surgery to assess the presence or absence of blood flow through the vascular loop, and samples were collected for histological analysis. This cycle was performed five times.

RESULTS

Of the rats euthanized four to five weeks after the first surgery, no blood flow was observed through the graft in 80% of the cases. In the group euthanized three weeks after the first surgery, no blood flow was observed in 20% of the cases. In the groups euthanized one to two weeks after the first surgery, blood flow through the vascular loop was observed in all animals. Moreover, intimal proliferation tended to increase with the duration of the postoperative period. Two weeks after surgery, intimal proliferation increased slightly, whereas strong intimal proliferation was observed in all rats evaluated five weeks after surgery.

CONCLUSION

Intimal proliferation was the most significant change noted in venous grafts as a function of the duration of the postoperative period and was directly correlated with graft occlusion. In cases in which vascular loops are required during free flap reconstruction, both procedures should preferably be performed during the same surgery.

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.

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.

Predictive Value of the No-Reflow Phenomenon and Epicardial Adipose Tissue for Clinical Outcomes After Primary Percutaneous Coronary Intervention

INTRODUCTION

The determinants of clinical outcomes in patients with acute ST-elevation myocardial infarction (STEMI) are still being debated. The aim of this study was to investigate the prognostic value of the no-reflow phenomenon and epicardial adipose tissue (EAT) thickness for clinical outcomes in patients undergoing primary percutaneous coronary intervention (pPCI) for STEMI.

METHODS

The present study prospectively included 114 consecutive patients (mean age 54 ± 10 years, 15 women) who underwent successful pPCI. Patients were divided into two groups according to the occurrence of the no-reflow phenomenon and further subdivided according to the tertile of EAT thickness (Group I <5.1 mm, Group II ≥5.1 mm). We assessed the composite and separate occurrence of major adverse cardiac events.

RESULTS

Throughout the 3-year follow up, the number of admissions for heart failure was significantly higher in patients with no-reflow (n=5 [20%] vs. n=1 [1%], p=0.003) and in female patients (n=4 [26%] vs. n=2 [2%], p=0.004). In the subgroup analysis, group I patients with no-reflow showed a higher frequency of admission for heart failure (n=4 [44%] vs. n=1 [6%], p=0.04). However, multivariate logistic regression analysis demonstrated that only no-reflow and female sex independently predicted admission for heart failure (OR: 19.3, 95%CI: 1.4-269.7, p=0.03, and OR: 24.9, 95%CI: 2.2-288.8, p=0.01, respectively).

CONCLUSION

No-reflow and female sex are independent predictors of admission for heart failure in the longterm follow up of patients with STEMI. However, EAT thickness is not associated with clinical outcomes after pPCI.

Effect of microvascular obstruction and intramyocardial hemorrhage by CMR on LV remodeling and outcomes after myocardial infarction: a systematic review and meta-analysis

The goal of this systematic analysis is to provide a comprehensive review of the current cardiac magnetic resonance data on microvascular obstruction (MVO) and intramyocardial hemorrhage (IMH). Data related to the association of MVO and IMH in patients with acute myocardial infarction (MI) with left ventricular (LV) function, volumes, adverse LV remodeling, and major adverse cardiac events (MACE) were critically analyzed. MVO is associated with a lower ejection fraction, increased ventricular volumes and infarct size, and a greater risk of MACE. Late MVO is shown to be a stronger prognostic marker for MACE and cardiac death, recurrent MI, congestive heart failure/heart failure hospitalization, and follow-up LV end-systolic volumes than early MVO. IMH is associated with LV remodeling and MACE on pooled analysis, but because of limited data and heterogeneity in study methodology, the effects of IMH on remodeling require further investigation.

Assessment of left and right ventricular diastolic and systolic functions using two-dimensional speckle-tracking echocardiography in patients with coronary slow-flow phenomenon

OBJECTIVE

Coronary slow-flow phenomenon (CSFP) is an angiographic diagnosis characterised by a low rate of flow of contrast agent in the normal or near-normal epicardial coronary arteries. Many of the patients with CSFP may experience recurrent acute coronary syndromes. However, current clinical practice tends to underestimate the impact of CSFP due to the yet unknown effect on the cardiac function. This study was performed to evaluate left ventricular (LV) and right ventricular (RV) diastolic and systolic functions, using two-dimensional (2D) longitudinal strain and strain rate, in patients with CSFP, and to determine the relationships between the thrombolysis in myocardial infarction (TIMI) frame count (TFC) and LV and RV diastolic and systolic functions.

METHODS

Sixty-three patients with CSFP and 45 age- and sex-matched controls without CSFP were enrolled in the study. Diagnosis of CSFP was made by TFC. LV and RV diastolic and systolic functions were assessed by 2D speckle-tracking echocardiography.

RESULTS

LV peak early diastolic longitudinal strain rate (LSRe) was lower in patients with CSFP than in controls (P = 0.01). LV peak systolic longitudinal strain (LS) and LV peak systolic longitudinal strain rate (LSRs) were lower in patients with CSFP than in controls (P = 0.004 and P = 0.03, respectively). There was no difference in LV ejection fraction. RV peak early diastolic longitudinal strain rate (RSRe) was lower in patients with CSFP than in controls (P = 0.03). There were no differences in RV peak systolic longitudinal strain (RS), RV peak systolic longitudinal strain rate (RSRs), or RV fractional area change among the groups. The mean TFC correlated negatively with LSRe and RSRe in patients with CSFP (r = -0.26, P = 0.04 and r = -0.32, P = 0.01, respectively).

CONCLUSIONS

LV diastolic and systolic functions were impaired in patients with CSFP. CSFP also affected RV diastolic function, but not RV systolic function.

Coronary slow flow phenomenon associated with high serum levels of soluble CD40 ligand and urotensin II: a multi-marker approach

BACKGROUND

The aim of this study was to evaluate the serum soluble CD40 ligand (sCD40L) levels, serum uroten- sin II levels, and serum leptin levels as an indirect indicator of endothelial dysfunction, inflammation, and atherosclerosis at the microvascular level, and the comparison of those values with those of the control group with a nor- mal coronary flow pattern.

METHODS

The study included 35 consecutive patients (17 women, 18 men; average age: 51.20 ± 10.93 years) in our hospital who underwent coronary angiography due to objective myocardial ischemia and in whom slow coronary flow was detected. The control group included 34 consecutive patients with normal coronary flow pattern (18 women, 16 men; average age: 54.59 ± 12.40 years). The coronary flow rates of all patients and control subjects were documented by the thrombolysis in myocardial infarction (TIMI) frame count. Serum sCD40L concentrations, serum urotensin II concentrations and serum leptin concentrations were measured by an enzyme-linked immunosorbent assay method using commercially available kits.

RESULTS

The corrected TIMI frame count for LAD, Cx, RCA, and mean TIMI frame count were significantly higher in patients with slow coronary flow (SCF), compared to subjects with normal coronary flow (43.8 ± 1.7 vs. 17.7 ± 4.7, p < 0.001; 27.9 ± 6.9 vs. 11.9 ± 4.8, p < 0.001; 25.4 ± 8.4 vs. 11.1 ± 3.1, p < 0.001; and 32.3 ± 6.4 vs. 13.7 ± 5, p < 0.001, respectively). The serum soluble CD40 ligand and serum urotensin II levels were significantly higher in the slow coronary flow group compared to the control group (12.00 ± 5.43 ng/mL--6.49 ± 5.03 ng/mL, p < 0.001; and 50.94 ± 34.28 pg/mL--26.91 ± 11.52 pg/mL, p < 0.001, respectively). In addition, there was no statistically significant difference between the slow coronary flow group and the control group with regard to serum leptin levels and hs-CRP levels (both p > 0.05).

CONCLUSIONS

This study suggests that soluble CD40 ligand and urotensin II likely play a role in the pathogenesis of slow coronary flow.

Increased neutrophil-to-lymphocyte ratio predicts persistent coronary no-flow after wire insertion in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention

OBJECTIVES

Acute ST-segment elevation myocardial infarction patients presenting persistent no-flow after wire insertion have a lower survival rate despite successful mechanical intervention. The neutrophil-to-lymphocyte ratio has been associated with increased mortality and worse clinical outcomes in ST-segment elevation myocardial infarction. We hypothesized that an elevated neutrophil-to-lymphocyte ratio would also be associated with a persistent Thrombolysis In Myocardial Infarction flow grade of 0 after wire insertion in patients undergoing primary percutaneous coronary intervention.

METHODS

A total of 644 patients with ST-segment elevation myocardial infarction who underwent primary percutaneous coronary intervention within 12 hours of symptom onset were included in our study. Blood samples were drawn immediately upon hospital admission. The patients were divided into 3 groups according to their Thrombolysis In Myocardial Infarction flow grade: Thrombolysis In Myocardial Infarction flow grade 0 after wire insertion, Thrombolysis In Myocardial Infarction flow grade 1-3 after wire insertion and Thrombolysis In Myocardial Infarction flow grade 1-3 at baseline.

RESULTS

The neutrophil-to-lymphocyte ratio was significantly higher in the group with Thrombolysis In Myocardial Infarction flow grade 0 after wire insertion compared with the group with Thrombolysis In Myocardial Infarction flow grade 1-3 after wire insertion and the group with Thrombolysis In Myocardial Infarction flow grade 1-3 at baseline. The group with Thrombolysis In Myocardial Infarction flow grade 0 after wire insertion also had a significantly higher in-hospital mortality rate. Persistent coronary no-flow after wire insertion was independently associated with the neutrophil-to-lymphocyte ratio.

CONCLUSIONS

An increased neutrophil-to-lymphocyte ratio on admission is significantly associated with persistent coronary no-flow after wire insertion in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention.

[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.

Arterial elasticity in obese subjects with coronary slow flow phenomenon

BACKGROUND

Coronary slow flow phenomenon (CSFP) is a functional and structural disease that is diagnosed by coronary angiogram.

OBJECTIVES

To evaluate the possible association between CSFP and small artery elasticity in an effort to understand the pathogenesis of CSFP.

METHODS

The study population comprised 12 patients with normal coronary arteries and CSFP and 12 with normal coronary arteries without CSFP. We measured conjugated diene formation at 234 nm during low density lipoprotein (LDL) oxidation, as well as platelet aggregation. We estimated, noninvasively, arterial elasticity parameters. Mann-Whitney nonparametric test was used to compare differences between the groups. Data are presented as mean +/- standard deviation.

RESULTS

Waist circumference was 99.2 +/- 8.8 cm and 114.9 +/- 10.5 cm in the normal flow and CSFP groups, respectively (P = 0.003). Four patients in the CSFP group and one in the normal flow group had type 2 diabetes. Area under the curve in the oral glucose tolerance test was 22% higher in the CSFP than in the normal group (P = 0.04). There was no difference in systolic and diastolic blood pressure, plasma concentrations of total cholesterol, triglycerides, high density lipoprotein, LDL and platelet aggregation parameters between the groups. Lag time required until initiation of LDL oxidation in the presence of CuSO4 was 17% longer (P = 0.02) and homocysteine fasting plasma concentration was 81% lower (P = 0.05) in the normal flow group. Large artery elasticity was the same in both groups. Small artery elasticity was 5 +/- 1.5 ml/mmHg x 100 in normal flow subjects and 6.1 +/- 1.9 ml/mmHg x 100 in the CSFP patients (P = 0.02).

CONCLUSIONS

Patients with CSFP had more metabolic derangements. Arterial stiffness was not increased in CSFP.

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.

[Prognostic significance of admission N-terminal pro-brain natriuretic peptide in predicting angiographic no-reflow phenomenon during percutaneous coronary intervention in patients with acute myocardial infarction]

OBJECTIVE

To determine the relationship between N-terminal pro-brain-type natriuretic peptide (NT-proBNP) and angiographic no-reflow phenomenon in patients with acute myocardial infarction (AMI) after primary percutaneous coronary intervention (PCI).

METHODS

The data of 106 consecutive AMI patients undergoing primary PCl were collected and analyzed retrospectively. NT-proBNP was obtained pre-PCI at admission. According to the NT-proBNP level, they were divided into normal and elevated NT-proBNP groups. The no-reflow phenomenon was defined as an angiographic outcome of Thrombolysis In Myocardial Infarction (TIMI) grade < 3 without accompanying mechanical factors.

RESULTS

The patients with elevated NT-proBNP on admission had a higher incidence of no-reflow phenomenon than those with NT-proBNP level. Compared to normal reflow counterparts, no-reflow patients had a higher NT-proBNP level [1883 ng/L (484 ∼ 5500 ng/L) vs 220 ng/L (87 ∼ 926 ng/L) P = 0.046]. Multivariate analysis showed that a high NT-proBNP level (NT-proBNP > 1765 ng/L) on admission was an independent predictor of no-reflow. This cut-off value yielded a sensitivity of 60.0% and a specificity of 87.5% respectively.

CONCLUSION

The NT-proBNP level on admission may be a prognostic biomarker in the prediction of the development of angiographic "no-reflow" phenomenon after primary PCI for AMI patients.

[Correlation of serum uric acid levels with coronary flow in patients with ST-segment elevation myocardial infarction undergoing primary coronary intervention]

OBJECTIVE

To explore the association of the uric acid levels and coronary blood flow in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI).

METHODS

A total of 276 STEMI patients undergoing primary PCI were enrolled and divided into 2 groups based upon the Thrombolysis in Myocardial Infarction (TIMI) flow grade. No-reflow was defined as TIMI Grade 0, 1 and 2 flows. The association of uric acid levels on admission with TIMI flow grade after PCI was assessed by multivariate Logistic regression. Major adverse cardiac events (MACE) were defined as death, non-fatal myocardial infarction and need for repeat percutaneous revascularization or coronary artery bypass grafting.

RESULTS

The uric acid level was significantly higher in the no-reflow group (n = 57) than that of the normal-flow group (n = 219, 372 ± 111 vs 303 ± 102, P < 0.01). In-hospital MACEs were significantly higher in the patients with no reflow (8.8% vs 1.8%, P = 0.016). A uric acid level ≥ 345 mmol/L measured on admission had a 61.2% sensitivity and 77.5% specificity in predicting no-reflow at ROC curve analysis. At multivariate analyses, high plasma uric acid (OR 1.01, 95%CI 1.01 - 1.01, P < 0.01), neutrophil count (OR 1.02, 95%CI 1.00 - 1.06, P < 0.01), admission plasma glucose (OR 1.14, 95%CI 1.08 - 1.21, P < 0.01), time from pain to PCI (OR 1.67, 95%CI 0.46 - 5.97, P = 0.012), pre PCI thrombus score ≥ 4 (OR 2.67, 95%CI 1.29 - 5.13, P = 0.008), collateral circulation grade ≤ 1 (OR 1.86, 95%CI 1.27 - 2.73, P = 0.008), and Killip classes (OR 2.01, 95%CI 1.01 - 3.94, P = 0.042) were independent predictors of no-reflow post primary PCI.

CONCLUSIONS

The plasma level of uric acid on admission is a strong and independent predictor of poor coronary blood flow following at post-primary PCI among STEMI patients. Uric acid levels may be a useful biomarker of risk stratification.

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.

Effects of L-NAME on coronary blood flow, infarct size and the extent of the no-reflow phenomenon

BACKGROUND

NOS inhibitors are a potential treatment for patients with cardiogenic shock during acute myocardial infarction. Despite hemodynamic efficacy, their effects on the extent of myocardial infarction (MI) and the no-reflow phenomenon (NRP) have not been clarified.

METHODS

Sixteen pigs underwent occlusion of the mid left anterior descending coronary artery for 1h followed by reperfusion for 2h. Coronary blood flow (CBF), distal to the occlusion site, was measured. In eight experiments, L-NAME (non selective NO synthetase inhibitor) administration began 10 min before the onset of reperfusion and continued for 2h (loading dose 1mg/kg, perfusion rate: 1mg/kg/h) (L-NAME group). Eight pigs received similarly normal saline (controls). At the end of each experiment, the myocardial area at risk (MAR) and extent of MI and NRP were measured.

RESULTS

Hemodynamics at baseline and during ischemia were similar in both groups. During reperfusion, the mean aortic blood pressure was significantly higher in the l-NAME group. In both groups, CBF reached a peak at 5 min of reperfusion, (no difference between groups). CBF gradually returned to baseline levels within 60 min of reperfusion in both groups. No statistically significant differences in the extent of the NRP (51.8 ± 19.7 vs 60.9 ± 11.4 p=0.35) and MI (77.9 ± 13.9 vs 77.1 ± 8.8 p=0.92), both expressed as a percentage of MAR, were observed between the L-NAME group and the control group.

CONCLUSIONS

L-NAME administration started immediately before and maintained throughout reperfusion has no effect on NRP and MI size. L-NAME might stabilize patients with post-MI cardiogenic shock without adverse effects on infarct size.

Beta-blocker use is not associated with slow flow during rotational atherectomy

OBJECTIVES

The purpose of this study was to investigate the association between beta-blocker use and slow flow during rotational atherectomy (RA).

BACKGROUND

RA is often performed as part of percutaneous coronary interventions for the treatment of calcified lesions; however, the procedure can be complicated by slow flow. Previous reports suggested that the use of beta-blockers was associated with slow flow during RA.

METHODS

A total of 186 patients who received RA were included, and 87 patients were on beta-blockers. The occurrence of slow flow was compared between the beta-blocker group (n = 87) and the non-beta-blocker group (n = 99). Multivariate logistic regression analysis was performed to investigate whether the use of beta-blockers was associated with slow flow.

RESULTS

The occurrence of slow flow was not different between the beta-blocker group (29.9%) and the non-beta-blocker group (24.2%; P=.39). The use of beta-blockers was not significantly associated with slow flow (odds ratio, 0.75; 95% confidence interval, 0.34-1.68; P=.49) after controlling for all potential confounding factors.

CONCLUSIONS

There was no definitive association between slow flow and the use of beta-blockers during RA. There is no need to discontinue beta-blockers in patients receiving RA.

[Myocardial no-reflow phenomenon: recent knowledges]

Early revascularization of the infarct-related artery by primary percutaneous coronary intervention (PPCI) has become the gold standard therapy in ST-segment elevation myocardial infarction (STEMI). However, in a number of patient undergoing PPCI, epicardial coronary artery reperfusion: does not translate into myocardial reperfusion: a phenomenon called as no-reflow. The no-reflow phenomenon has a multifactorial pathogenesis, including: distal embolization, ischemia-reperfusion injury, and individual predisposition of coronary microcirculation to injury. Angiographic and electrocardiographic indexes may be used for the diagnosis. Also, lack of ST-segment elevation resolution is considered an established marker of no-reflow. Importantly, the no-reflow phenomenon provides prognostic information in STEMI patients because it is associated with low ventricular ejection fraction, adverse left ventricular remodelling and mortality at follow-up. Various mechanical devices and pharmacological approaches have been proposed to prevent and to treat the phenomenon: the assessment of mechanisms of no-reflow might guide the development of personalized form of treatment. This paper will be focused on the postulated mechanisms of the phenomenon, modalities for the diagnosis, and the main treatment options.

Coronary slow flow and acute coronary syndrome in a patient with spinal cord injury

We report the case of a 55-year-old man who presented with acute coronary syndrome due to coronary slow flow after spinal cord injury. Data regarding the causes and clinical manifestations of coronary slow flow are inconclusive, but the autonomic nervous system is believed to be at least a contributing factor. The predominant vagal activity causes vasodilation and hemostasis, which can lead to acute coronary syndrome. We hereby call attention to hyperactive parasympathetic tonicity, which can lead to coronary slow flow and acute coronary syndrome in acute spinal cord injury patients.

Endothelin-1 release in acute myocardial infarction as a predictor of long-term prognosis and no-reflow assessed by contrast-enhanced magnetic resonance imaging

BACKGROUND

No-reflow after primary percutaneous coronary intervention (PCI) in ST-elevation myocardial infarction (STEMI) is associated with poor prognosis. Endothelin-1 (ET-1) is a potent endothelium-derived vasoconstrictor that might aggravate reperfusion injury. The aim of our study was to assess the relationship between systemic ET-1 levels and the occurrence of no-reflow as well as to evaluate the prognostic value of ET-1 in a high-risk STEMI population.

METHODS

We examined 128 consecutive patients undergoing primary PCI in acute STEMI <12 hours after symptom onset. Endothelin-1 was assessed before and immediately after primary PCI. Patients were categorized into 2 groups defined by the median ET-1 level on admission. No-reflow was assessed by 3 different methods after PCI: angiographic Thrombolysis in Myocardial Infarction (TIMI) flow and myocardial blush grade, electrocardiographic ST-resolution, and microvascular obstruction (MO) measured by cardiac magnetic resonance imaging (MRI). The primary clinical end points were mortality and major adverse cardiovascular events. Clinical follow-up was conducted after a median of 19 months.

RESULTS

Patients with angiographically (TIMI flow < or =2 or TIMI flow 3 with final myocardial bush grade < or =2 after PCI), electrocardiographically (ST-resolution <30%), and MRI- (presence of MO) detected no-reflow had significantly higher ET-1 levels on admission. At multivariable logistic regression analysis, ET-1 levels on admission were the only significant predictor of MRI-detected no-reflow (P = .03) together with left ventricular ejection fraction (P = .002). An elevated ET-1 level > or = the median on admission was a significant predictor of long-term mortality.

CONCLUSIONS

Endothelin-1 on admission is associated with no-reflow and increased long-term mortality in a high-risk STEMI population reperfused by primary PCI.

Pharmacological approach of no-reflow phenomenon related with percutaneous coronary interventions

The no-reflow phenomenon (NRP) is characterized by an inadequate myocardial tissue perfusion in the presence of a patent epicardial coronary artery. It generally occurs after temporary occlusion of the artery causing myocardial ischemia and necrosis that persist after relief of the vessel occlusion, without evidence of epicardial mechanical obstruction. Currently, the main scenario of NRP is the setting of percutaneous coronary interventions (PCI), especially in patients with acute myocardial infarction or saphenous vein graft disease, and its occurrence is associated with adverse clinical outcomes. Pathophysiology of NRP is not fully understood but it seems to be related with microvascular damage. Several mechanisms have been involved, such as distal microembolization, interstitial and intracellular edema, coronary spasm and capillary plugging. Diagnosis of NRP is generally based on clinical and angiographic data. Several methods have been proposed for the assessment of NRP, such as electrocardiography, myocardial contrast echocardiography, contrast-enhanced magnetic resonance imaging, nuclear imaging or positron emission tomography, that have demonstrated additional prognostic value over angiography. There are different pharmacological and mechanical approaches for the prevention of NRP but none of them have demonstrated a clear efficacy. The treatment of established NRP is mainly based on the administration of coronary vasodilators, like adenosine, verapamil or nitroprusside, but clinical results are frequently disappointing. The objective of this review is to describe the state of the art of the pathophysiology, diagnosis and pharmacological management of NRP.