Prospective, Multicenter Study of Thrombectomy in Patients with Acute Myocardial Infarction: The X-Tract AMI Registry

Large intracoronary thrombus and its management during primary PCI

Large intracoronary thrombus has been reported in significant number of patients with STEMI. Primary PCI is the current standard of care in patients of STEMI. Despite the availability of dual antiplatelets, GP IIb/IIIa inhibitor and effective anticoagulation regimens, large intracoronary thrombus remains one of the biggest challenge to interventional cardiologists during primary PCI. Large intracoronary thrombus may lead to distal embolization, no/slow reflow or embolization into a non-culprit vessel and is associated with adverse cardiovascular outcome. There is no ideal management strategy. We hereby discuss the current available methods/strategies to deal with large thrombus burden encountered during primary PCI, in the current manuscript.

Arctigenin exerts protective effects against myocardial infarction via regulation of iNOS, COX‑2, ERK1/2 and HO‑1 in rats

The present study aimed to determine the protective effects of arctigenin against myocardial infarction (MI), and its effects on oxidative stress and inflammation in rats. Left anterior coronary arteries of Sprague‑Dawley rats were ligated, in order to generate an acute MI (AMI) model. Arctigenin was administered to AMI rats at 0, 50, 100 or 200 µmol/kg. Western blotting and ELISAs were performed to analyze protein expression and enzyme activity. Arctigenin was demonstrated to effectively inhibit the levels of alanine transaminase, creatine kinase‑MB and lactate dehydrogenase, and to reduce infarct size in AMI rats. In addition, the activity levels of malondialdehyde, interleukin (IL)‑1β and IL‑6 were significantly suppressed, and the levels of glutathione peroxidase, catalase and superoxide dismutase were significantly increased by arctigenin treatment. Arctigenin treatment also suppressed the protein expression levels of inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX‑2) and heme oxygenase 1 (HO‑1), and increased the protein expression levels of phosphorylated‑extracellular signal‑regulated kinase 1/2 (p‑ERK1/2) in AMI rats. Overall, the results of the present study suggest that arctigenin may inhibit MI, and exhibits antioxidative and anti‑inflammatory effects through regulation of the iNOS, COX‑2, ERK1/2 and HO‑1 pathways in a rat model of AMI.

Predictors of No-Reflow Phenomenon in Young Patients With Acute ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

No-reflow is of prognostic value in ST-segment elevation myocardial infarction (STEMI) but has not been extensively investigated in young patients. Young patients with STEMI admitted within 12 hours from symptom onset and treated by primary percutaneous coronary intervention (pPCI) were recruited. Patients were classified into 2 groups based on postintervention thrombolysis in myocardial infarction (TIMI) flow grade; no-reflow: TIMI flow grade 0, 1 or 2 (group 1; n = 27; 21 men, mean age: 42 ± 4 years); and angiographic success: TIMI flow grade 3 (group 2; n = 118; 110 men, mean age: 43 ± 4 years). Adjusted odds ratios were 13.79 for female gender ( P < .001; confidence interval [CI] = 1.88-101.26), 2.09 for pain to balloon time ( P < .017; CI = 1.14-3.812), 12.29 for high TIMI thrombus grade ( P = .012; CI = 1.74-86.94), 0.04 for tirofiban use ( P < .001; CI = 0.01-0.22), 5.19 for mean platelet volume (MPV; P < .001; CI = 2.44-11.01), and 1.008 for platelet–lymphocyte ratio (PLR; P = .034; CI = 1.001-1.016). In conclusion, female gender, pain to balloon time, high TIMI thrombus grade, tirofiban, MPV, and PLR were independent predictors of no-reflow in young patients with STEMI after pPCI.

The Relation Between No-Reflow Phenomenon and Complete Blood Count Parameters

The no-reflow (NR) phenomenon represents an acute reduction in coronary blood flow without coronary vessel obstruction, coronary vessel dissection, spasm, or thrombosis. No reflow is an important complication among patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI). The complete blood count (CBC) is one of the most frequently ordered laboratory tests in clinical practice. Various studies have evaluated the performance of CBC parameters to predict disease severity and mortality risk. Automated cell counters are routinely available in many clinical laboratories and can be used to determine red blood cell distrubiton width (RDW), platetecrit, platelet count, and and some ratios like the neutrophil-lymphocyte ratio and RDW-platelet ratio. These hematological markers have been reported to be independent predictors of impaired angiographic reperfusion and long-term mortality among patients with STEMI undergoing pPCI. In this context, we reviewed the role of admission CBC parameters for the prediction of NR in patients with STEMI undergoing pPCI.

Clinical evaluation of thrombus aspiration combined with tirofiban in patients with acute myocardial infarction with elective percutaneous coronary intervention

OBJECTIVE

To compare the efficacy and safety of combined treatment with thrombus aspiration and intracoronary tirofiban in patients with acute myocardial infarction (MI), with elective percutaneous coronary intervention (PCI).

METHODS

Patients undergoing elective PCI during recovery from acute MI were randomized into two groups; the intervention group received thrombus aspiration and intracoronary tirofiban; the control group received conventional PCI. Baseline clinical characteristics, postoperative coronary blood flow (thrombolysis in myocardial infarction [TIMI] grade), TIMI myocardial perfusion (TMP) grade, no/slow reflow rate and cardiac function (measured by echocardiography 1 month postoperatively) were evaluated. Major adverse cardiac event rate and bleeding complications during surgery (and at 1 month and 1 year postoperatively) were also evaluated.

RESULTS

A total of 80 patients were included. Postoperatively, the number of patients with TIMI flow grade 3 and the mean TMP grade were both significantly higher, and the no/slow reflow rate was significantly lower, in the intervention group versus the control group. Echocardiography indicated that cardiac function was significantly improved in the intervention group compared with the control group. There were no major complications in either study group.

CONCLUSION

Thrombus aspiration combined with intracoronary tirofiban during recovery from acute MI was effective and relatively well tolerated.

Myocardial no-reflow in humans

In a variable proportion of patients presenting with ST-segment elevation myocardial infarction, ranging from 5% to 50%, primary percutaneous coronary intervention achieves epicardial coronary artery reperfusion but not myocardial reperfusion, a condition known as no-reflow. Of note, no-reflow is associated with a worse prognosis at follow-up. The phenomenon has a multifactorial pathogenesis including: distal embolization, ischemia-reperfusion injury, and individual predisposition of coronary microcirculation to injury. Moreover, it is spontaneously reversible in some patients, thus suggesting that it might be amenable to treatment also when we fail to prevent it. Several recent studies have shown that biomarkers and other easily available clinical parameters can predict the risk of no-reflow and can help in the assessment of the multiple mechanisms of the phenomenon. Several therapeutic strategies have been tested for the prevention and treatment of no-reflow. In particular, thrombus aspiration before stent implantation prevents distal embolization and has been recently shown to improve myocardial perfusion and clinical outcome as compared with the standard procedure. However, it is conceivable that the relevance of each pathogenetic component of no-reflow is different in different patients, thus explaining the occurrence of no-reflow despite the use of mechanical thrombus aspiration. Thus, in this review article, for the first time, we propose a personalized management of no-reflow on the basis of the assessment of the prevailing mechanisms of no-reflow operating in each patient.

Effect of intracoronary thrombectomy on 30-day mortality in non-diabetic patients with acute hyperglycemia after acute myocardial infarction

BACKGROUND

There is limited evidence about useful therapeutic interventions for patients with acute hyperglycemia (AH) after acute myocardial infarction (AMI).

METHODS

We studied 2433 consecutive non-diabetic AMI patients who underwent percutaneous coronary intervention (PCI) within 24h after the onset. Patients were divided into two groups according to the presence or absence of AH (admission serum glucose level ≥ 11.1 mmol/l). We assessed the association between intracoronary thrombectomy and the clinical outcome in AMI patients with AH.

RESULTS

Patients with AH had more risk factors than those without AH. The 30-day mortality rate of patients with AH was significantly higher than that of those without (11.7% vs 1.7%, p<0.001). Among patients with AH, the 30-day mortality rate was significantly lower for those with intracoronary thrombectomy than those without it (4.9% vs 17.2%, p=0.004). Among patients without AH, however, the 30-day mortality rate was similar between those with and without intracoronary thrombectomy (1.5% vs 1.9%, p=NS). Multivariate analysis showed that intracoronary thrombectomy was associated with an improved 30-day mortality rate for patients with AH (hazard ratio: HR 0.184, 95% CI 0.057-0.598, p=0.005).

CONCLUSIONS

In AMI patients with AH, intracoronary thrombectomy prior to PCI might improve the 30-day mortality rate.

Comparison of two visual angiographic perfusion grades in acute myocardial infarction

INTRODUCTION

Prognosis after opening the obstructed coronary artery in acute myocardial infarction (AMI) is influenced by several factors. In routine clinical practice, revascularization is considered to be successful when the restoration of epicardial blood-flow is complete. However, the patent epicardial artery does not always provide functional recovery in the myocardium. There are two visual angiographic grades to assess myocardial perfusion: myocardial blush grade (MBG) and TIMI myocardial perfusion grade (TMP). The aim of our study was to compare these two parameters, how they correlate with short-term indicators of myocardial damage.

PATIENTS AND METHODS

The two visual grades were assessed along with enzymatic infarct size as creatine kinase release (CK), echocardiographic left ventricular ejection fraction (LVEF), and ST-segment resolution (STR) in 62 patients with acute myocardial infarction and successful revascularization.

RESULTS

Better correlation was found with TMP in case of all clinical parameters (CK: R= - 0.687, P<0.001; LVEF: R=0.586, P<0.001; STR: R=0.574, P<0.001). MBG also showed significant correlations with clinical measurements, except for enzymatic infarct size (CK: R=- 0.062, P=0.626; LVEF: R=0.389, P=0.002; STR: R=0.348, P=0.006).

CONCLUSION

Our findings suggest that the clearance of the dye (described by TMP) is more characteristic to myocardial recovery after AMI, than maximal contrast density (described by MBG) in the clinical practice.