Early Infarct-related Artery Patency Research Articles

Admission homocysteine is an independent predictor of spontaneous reperfusion and early infarct-related artery patency before primary percutaneous coronary intervention in ST-segment elevation myocardial infarction

BackgroundSpontaneous reperfusion (SR) and early infarct related artery (IRA) patency before primary percutaneous coronary intervention (PPCI) might bring extra benefit for patients with ST-segment elevation myocardial infarction (STEMI). This study premilinarily screened the independent predictors of SR, and assessed the relationship between SR and plasma homocysteine (HCY).MethodsThe medical records of 998 patients who were diagnosed as STEMI and underwent emergency coronary angiography were retrospectively studied, SR was defined as achievement of TIMI grade 3 flow in the IRA before PCI. The baseline characteristics, clinical manifestations and hematological variables were compared between SR and NSR group. Optimal cutoff point of HCY was calculated with receiving operating characteristics (ROC) analysis, multivariate logistic regression models were used to identify predictors of SR.Results229 (22.95%) patients showed angiographic SR. For HCY, the area under the curve was 0.70 (95% CI: 0.63–0.77, P = 0.034), the optimized cut off point was 17.55 μmol/L. Preinfarct angina (95% CI: 1.61–5.65, P = 0.0005), plasma C-reactive protein (CRP) level (95% CI: 0.87–0.99, P = 0.016) and HCY < 17.55 μmol/L (95% CI: 2.43–8.72, P < 0.0001) were found to be independent predictors for SR.ConclusionIn patients with STEMI, HCY < 17.55 μmol/L, preinfarct angina and plasma CRP level were independent predictors of SR.

Impact of acute infarct-related artery patency before percutaneous coronary intervention on 30-day outcomes in patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention in the EUROMAX trial.

Early infarct-related artery patency has been associated with improved outcomes in patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention. However, it is unknown whether this relationship persists in contemporary practice with pre-hospital initiation of treatment, use of novel P2Y12 inhibitors and frequent use of drug-eluting stents. The purpose of the study was to determine the impact of early infarct-related artery patency on outcomes in the contemporary EUROMAX trial. A total of 2218 patients were enrolled. The current analysis was done on 1863 patients who underwent percutaneous coronary intervention and had infarct-related artery patency data. Thirty-day outcomes were compared according to infarct-related artery flow before percutaneous coronary intervention (Thrombolysis in Myocardial Infarction (TIMI) flow 0/1 vs. TIMI flow 2/3), and interaction with antithrombotic strategy was examined. A patent infarct-related artery (TIMI flow 2/3) was present in 707 patients (37.9%) and was associated with a higher rate of final TIMI 3 flow grade (98.9 vs. 92.6%; p<0.001). At 30 days, a patent infarct-related artery was associated with lower rates of cardiac death (1.3% vs. 2.9%; p=0.026) and the composite of death or myocardial infarction (2.7% vs. 4.6%; p=0.039). There were no interactions between antithrombotic treatment and the impact of infarct-related artery patency on cardiac death, myocardial infarction, or the composite of death or myocardial infarction (Breslow-Day interaction p-values of 0.21, 0.33 and 0.46, respectively). Despite evolution in primary percutaneous coronary intervention strategies, early infarct-related artery patency is still associated with higher procedural success and improved clinical outcomes. The choice of antithrombotic strategy did not interact with the benefits of a patent infarct-related artery at presentation.

Neutrophil to Lymphocyte Ratio in Acute ST-Segment Elevation Myocardial Infarction

BackgroundSpontaneous early patency of infarct-related artery (IRA) on arrival for primary percutaneous coronary intervention is associated with better short- and long-term prognosis in patients with ST-segment elevation myocardial infarction (STEMI). We aimed to investigate whether the hemographic parameters on admission are associated with spontaneous IRA patency. MethodsThis was a retrospective study of 1,625 patients with acute STEMI who underwent primary percutaneous coronary intervention <12hours after the onset of symptoms. ResultsAngiography showed patent IRA (prethrombolysis in myocardial infarction [TIMI] grade 3 flow) in 160 (9.8%) patients. Neutrophil count on admission (7.8 ± 2.4 × 103/μL versus 9.7 ± 3.8 × 103/μL; P < 0.001) was significantly lower and lymphocyte count (2.4 ± 1.0 × 103/μL versus 1.9 ± 1.1 × 103/μL; P < 0.001) on admission was significantly higher in the patent IRA group. Neutrophil to lymphocyte ratio (NLR) was significantly lower in the patent IRA group (4.1 ± 3.2 versus 6.9 ± 5.5; P < 0.001). Admission leukocyte counts (13 ± 4.0 × 103/μL versus 12 ± 3.4 × 103/μL; P < 0.001) and NLR (7.2 ± 5.8 versus 5.5 ± 4.4; P < 0.001) of the patients with TIMI thrombus score ≥4 were significantly higher than patients with TIMI thrombus score <4. In the multivariate analysis, NLR ≥4.5 (3.17 [95% confidence interval: 2.04-4.92]; P < 0.001) was found to be independently predicting an occluded IRA on initial angiography with a sensitivity of 62.7% and a specificity of 70%. ConclusionsNLR on admission is significantly related to angiographic thrombus burden and spontaneous early IRA patency in patients with acute STEMI.

The relationship between neutrophil/lymphocyte ratio and infarct-related artery patency before mechanical reperfusion in patients with ST-elevation myocardial infarction

Reduced baseline coronary flow in an infarct-related artery (IRA) before a primary percutaneous coronary intervention (PPCI) increases mortality in patients with ST-elevation myocardial infarction (STEMI). Increased neutrophil/lymphocyte (N/L) ratio has been linked to poor clinical outcomes in patients with STEMI. We investigated whether the N/L ratio, as measured at admission, was associated with IRA patency before mechanical reperfusion in patients with STEMI undergoing PPCI. A total of 404 patients who had undergone PPCI on a single culprit artery were enrolled in this study. According to thrombolysis in myocardial infarction (TIMI) flow grade in the IRA before PPCI, the study population was divided into two groups as TIMI 0 or 1 group (occluded IRA) and TIMI 2 or 3 group (patent IRA). The N/L ratios were found to be significantly higher in the TIMI flow 0/1 group when compared with the TIMI flow 2/3 group (6.08±3.94 vs. 4.01±2.87, P=0.001). The absence of early IRA patency was associated with higher Syntax score, mean platelet volume, creatine kinase-myocardial band, and troponin T levels (P=0.0001, P=0.03, P<0.001, and P=0.004, respectively), and lower left ventricular ejection fraction (P=0.02). Multivariate logistic regression analysis showed that the N/L ratio and Syntax score were independent predictors of IRA patency (odds ratio: 1.89, 95% confidence interval: 1.82-1.98; odds ratio=2.80, 95% confidence interval: 1.75-3.86, respectively; P=0.001). The N/L ratio has been found to be associated independently with early IRA patency before PPCI in patients who have undergone PCI for STEMI. This simple and cheap parameter can provide useful information on the related risk evaluation in these patients.

Impact of infarct-related artery patency before primary PCI on outcome in patients with ST-segment elevation myocardial infarction: the HORIZONS-AMI trial

We assessed the impact of early infarct-related artery (IRA) recanalisation on the outcomes of patients in the recently conducted, large-scale, multicentre HORIZONS-AMI trial. Of the 3,602 patients enrolled in the HORIZONS-AMI trial, 3,093 patients (85.9%) were treated with percutaneous coronary intervention (PCI) to a single artery. We analysed one-year outcomes in these patients according to the presence or absence of early IRA patency, defined as Thrombolysis in Myocardial Infarction (TIMI) 2 or 3 flow in the IRA. Baseline coronary angiography showed early IRA patency in 1,121 patients (36.2%), while 1,972 patients (63.8%) had TIMI 0 or 1 flow. The presence compared with the absence of early IRA patency was associated with better angiographic results after primary PCI with more TIMI 3 flow after PCI (93.2% vs. 82.9%, p<0.0001) and myocardial blush grade 2 or 3 (84.4% vs. 71.1%, p<0.0001). Early IRA patency was associated with lower rates of one-year mortality (2.5% vs. 3.9%, p=0.04) and definite or probable stent thrombosis (2.0% vs. 4.0%, p=0.002). In multivariable analysis, early IRA patency at baseline angiography was an independent predictor of reduced mortality at one year (HR 0.58, 95% CI: 0.36-0.98, p=0.02). Early IRA patency in patients with STEMI undergoing primary PCI is associated with better TIMI flow and myocardial blush post PCI and is an independent predictor of lower one-year mortality. ClinicalTrials.gov identifier NCT00433966.

Association of initial Thrombolysis in Myocardial Infarction flow grade with mortality among patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention: A National Registry of Myocardial Infarction-5 (NRMI-5) analysis

Initial epicardial coronary flow, as assessed by the Thrombolysis in Myocardial Infarction flow grade (TFG), prior to primary percutaneous coronary intervention (pPCI) for ST-segment elevation myocardial infarction (STEMI) has been associated with short- and long-term mortality in randomized clinical trials. This study was designed to determine the relationship between initial TFG and mortality in a large, heterogeneous, real-world population of STEMI patients undergoing pPCI. The relationship between pre-pPCI TFG among patients undergoing pPCI and in-hospital mortality was evaluated among STEMI patients from 2004 to 2006 in the National Registry of Myocardial Infarction. Of 8,337 STEMI patients, 6,595 (79.1%) had pre-pPCI TFG 0/1, 1,126 (13.5%) had pre-pPCI TFG 2, and 616 (7.4%) had pre-pPCI TFG 3. TFG 0/1 prior to pPCI was associated with 3.4% in-hospital mortality, whereas TFG 2 (2.0%) and TFG 3 (1.8%) were associated with significantly lower mortality (TFG 0/1 vs TFG 2, P = .013; TFG 0/1 vs TFG 3, P = .035). TFG 0/1 prior to pPCI was also associated with a significant increase in the composite of death, recurrent myocardial infarction, heart failure, and shock (16.1%) when compared with patients presenting with TFG 2 (11.5%; P < .001) and TFG 3 (7.6%; P < .001). The difference in this composite was also significant between patients presenting with TFG 2 and TFG 3 (P = .01). In a large, heterogeneous group of real-world patients presenting with STEMI, pre-pPCI TFG 0/1 is associated with higher in-hospital mortality and other major adverse cardiovascular events. These results corroborate prior to post hoc analyses from randomized clinical trials and support continued efforts aimed at safely establishing early infarct-related artery patency among patients with STEMI.

Duration of Symptoms Is Not Always the Key Modulator of the Choice of Reperfusion for ST-Elevation Myocardial Infarction

Fibrinolytic therapy (FT) and primary percutaneous coronary intervention (PCI) are both well-accepted reperfusion therapies in ST-segment elevation myocardial infarction (STEMI). The evidence of randomized clinical trials indicates a relatively modest difference in 30-day mortality (≈1%) in favor of primary PCI over fibrin-specific FT and was based on very timely primary PCI (ie, a primary PCI–related delay of 40 minutes [door-to-balloon less door-to-needle time]).1 Longer delays to primary PCI, which are far more frequent in clinical practice,2 are associated with attenuated benefit or no benefit at all, particularly when compared with fibrin-specific FT.3,4 The benefit of timely primary PCI over FT is likely to especially apply to higher-risk patients.5,6 Irrespective of the method of reperfusion, the potential for myocardial salvage and better clinical outcome is inversely proportional to ischemic time or its only available clinical surrogate, symptom duration.7–12 These considerations underpin the notion expressed in the American College of Cardiology/American Heart Association (ACC/AHA) guidelines on the treatment of STEMI that timely reperfusion therapy is likely more important in determining outcome than whether FT or primary PCI is the chosen reperfusion method.13 Response by Armstrong et al p 1310 The ACC/AHA STEMI guidelines highlight the time point of 3 hours of symptom duration in guiding the choice of reperfusion therapy. They state that if symptom duration is <3 hours, no preference exists between FT and primary PCI provided that treatment is timely (for FT, door-to-needle time <30 minutes; for primary PCI, door-to-balloon time <90 minutes and ≤60 minutes between estimated needle time and estimated balloon time). However, if symptom duration exceeds 3 hours, these guidelines favor primary PCI over FT, again provided that primary PCI can be performed in a timely fashion.13 This article reexamines the evidence that may or may not be the basis …

Can an initial loading dose of 600 mg of clopidogrel enhance early infarct-related artery patency in acute myocardial infarction?

Can an initial loading dose of 600 mg of clopidogrel enhance early infarct-related artery patency in acute myocardial infarction?

Overcoming thrombolytic resistance: Rationale and initial clinical experience combining thrombolytic therapy and glycoprotein IIb/IIIa receptor inhibition for acute myocardial infarction

OBJECTIVESWe sought to review the emerging data and the clinical rationale for combining glycoprotein (GP) IIb/IIIa inhibitors with thrombolytic therapy for acute myocardial infarction (AMI).BACKGROUNDAlthough thrombolytic therapy has been a major advance in the treatment of acute ST segment elevation MI, new single-bolus thrombolytic agents have been unable to break the “thrombolytic ceiling” in infarct-related artery (IRA) patency.METHODSRecent literature on GPIIb/IIIa inhibitors in acute coronary syndromes was reviewed.RESULTSA new approach toward improving current thrombolytic–antithrombotic regimens focuses on “targeted therapy” for each component of the occlusive coronary thrombus: fibrin, thrombin and platelets. For the fibrin component, front-loading and/or bolus dosing of plasminogen activators (PAs) has identified the currently available doses of tissue-type plasminogen activator (t-PA) and recombinant tissue-type plasminogen activator (r-PA). For the thrombin component, several recent trials have shown that lower doses of heparin improve the safety profile of the thrombolytic-antithrombotic regimen. For the platelet component, aspirin has been shown to be effective, but the GPIIb/IIIa inhibitors offer the potential for more effective platelet inhibition and improved clinical efficacy. The benefits of GPIIb/IIIa inhibition in reducing death, MI or urgent revascularization in the setting of percutaneous coronary intervention are well established. Emerging experimental and clinical data now suggest that combining GPIIb/IIIa inhibition with reduced-dose thrombolytic therapy may improve early IRA patency without increasing bleeding risk.CONCLUSIONSGiven the strong clinical and physiologic rationale, clinical investigation in acute ST segment elevation MI is currently focused on combining the potent GPIIb/IIIa receptor inhibitors with reduced-dose fibrinolytic agents in acute MI, with the goal of overcoming “thrombolytic resistance.”

Combination therapy for acute myocardial infarction: glycoprotein IIb/IIIa inhibitors plus thrombolysis.

Although thrombolytic therapy has been a major advance in the treatment of acute ST-segment elevation myocardial infarction (MI), new thrombolytic agents have been unable to improve early reperfusion. Because aspirin has been shown to be a very effective adjunctive agent in patients with acute MI, it has been hypothesized that the use of platelet glycoprotein (GP) IIb/IIIa receptor inhibitors combined with thrombolytic agents would lead to more effective platelet inhibition and improved angiographic and clinical efficacy. Emerging experimental and clinical data, including the Thrombolysis in Myocardial Infarction (TIMI)-14 trial, suggest that combining GP IIb/IIIa receptor inhibition with reduced-dose thrombolytic therapy improves early infarct-related artery patency without increasing bleeding risk. Thus, given the strong clinical and physiologic rationale, clinical investigation in patients with acute ST-segment elevation MI is currently focused on combining GP IIb/IIIa receptor inhibitors with reduced-dose fibrinolytic agents in acute MI.

Influence of time to treatment on early infarct-related artery patency after different thrombolytic regimens

Background In an in vitro model, recombinant tissue-type plasminogen activator was significantly more effective than streptokinase in dissolving 24-hour-old human blood clots. Therefore there might be a difference in the effect of time to treatment on the efficacy of these fibrinolytics with different fibrin specificity in patients with acute myocardial infarction. Methods and Results The effect of the interval between symptom onset and initiation of therapy on the efficacy of 6 different thrombolytic regimens was studied in a retrospective analysis of 6 angiographic trials with similar design. The patency of the infarct-related artery was assessed by angiography 90 minutes after initiation of thrombolysis in patients who were seen within 6 hours after symptom onset. Patency rates of patients with an interval of ≤3 hours and >3 hours between symptom onset and start of therapy were compared. There was no difference for Thrombolysis in Myocardial Infarction (TIMI) grade 3 perfusion after front-loaded alteplase (72.5% vs 76.3%) and reteplase (63.6% vs 63.2% ) between the 2 groups. In contrast, in patients treated with streptokinase (36.8% vs 27.6%, P = .09), anisoylated plasminogen streptokinase activator complex (59.5% vs 34.8%, P = .004), and urokinase (62.3% vs 41.7%, P = .03), TIMI 3 patency decreased with the increasing interval between symptom onset and initiation of therapy. Conclusions We conclude from our data that the thrombolytic efficacy of recombinant tissue-type plasminogen activator and reteplase does not decrease with the increasing interval between symptom onset and initiation of therapy. In contrast, after anisoylated plasminogen streptokinase activator complex, streptokinase, and urokinase treatment, a decrease in patency, especially TIMI-3 patency in patients treated after >3 hours after symptom onset, was observed. These results may influence the choice of the thrombolytic agent in patients who are seen >3 hours after symptom onset. (Am Heart J 1999;137:34-8.)

Early, Complete Infarct Vessel Patency: Arriving at a Gold Standard for Future Clinical Investigation in Myocardial Reperfusion.

Early clinical trials of thrombolytic therapy in the setting of acute myocardial infarction (AMI) demonstrated that early angiographic reperfusion correlated with improved survival. This supported the open-artery hypothesis that early reperfusion decreases infarct size, improves left ventricular function, and improves survival. Two subsequent comparative thrombolytic trials showed no difference in left ventricular function or survival between agents with different rates of reperfusion. Additionally, reduction in mortality was demonstrated without improvement in left ventricular function and with the late administration of thrombolytic therapy. Therefore, there was a real question as to the importance of infarct vessel patency, and its relation to clinical outcome. This article discusses the various markers of coronary artery patency, their relation to clinical outcome, and how they reflect perfusion at the tissue level. The coronary angiogram gives a snapshot view of the infarct-related artery (IRA) that does not reflect the dynamic process of vessel reocclusion and recanalization. The patent artery is therefore "open" at only a given time frame, and may undergo cyclic or complete reocclusion. Angiographically characterized flow has been demonstrated to be more clinically meaningful. The GUSTO-I trial was designed to test the open-artery hypothesis. This trial confirmed that improved early IRA patency and optimal (TIMI-3) flow correlated with improved survival. The presence of TIMI-3 flow in the IRA has consistently demonstrated significant improvement in patient morbidity and mortality, and conversely, less than optimal, but still "patent" (TIMI-2) flow in the IRA correlates with clinical outcomes observed in patients with occluded infarct vessels. Even TIMI-3 flow in the IRA does not always confirm perfusion of the myocardium at risk. Therefore, the "patent" IRA can be subsequently compromised by intermittent patency, reocclusion, less than TIMI-3 flow, and a "no-reflow" effect at the tissue level. The development of accurate, reliable non-invasive markers of IRA patency is crucial. This would allow a more selective application of invasive and interventional techniques to restore patency to the IRA. The merits and faults of these noninvasive markers are discussed. The ideal gold standard for establishing the adequacy of therapy in AMI is one that could detect rapid, complete, and sustained coronary reperfusion with adequate myocardial perfusion. Current technologic achievements allow an approach to this ideal; however, as of 1997, the coronary angiogram demonstrating TIMI-3 flow represents the clinically proven standard of optimal therapeutic efficacy.

Gender and Acute Myocardial Infarction: Is There a Different Response to Thrombolysis?

Objectives. This study sought to 1) determine the effect of gender on early and late infarct-related artery patency and reocclusion after thrombolytic therapy for acute myocardial infarction; 2) examine the effect of gender on left ventricular function in response to injury/reperfusion; and 3) assess the independent contribution of gender to early (30-day) mortality after acute myocardial infarction.Background. Women have a higher mortality rate than men after myocardial infarction. However, the effect of gender on infarct-related coronary artery patency and left ventricular response to injury/reperfusion have not been fully defined in the thrombolytic era.Methods. Patency rates and global and regional left ventricular function were determined in patients at 90 min and 5 to 7 days after thrombolytic therapy for acute myocardial infarction. The effect of gender on infarct-related artery patency and left ventricular function was determined. Thirty-day mortality differences between women and men were compared.Results. Women were significantly older and had more hypertension, diabetes, hypercholesterolemia, heart failure and shock. They were less likely to have had a previous myocardial infarction, history of smoking or previous bypass surgery. Ninety-minute patency rates (Thrombolysis in Myocardial Infarction [TIMI] flow grade 3) in women and men were 39% and 38%, respectively (p = 0.5). Reocclusion rates were 8.7% in women versus 5.1% in men (p = 0.14). Women had more recurrent ischemia than men (21.4% vs. 17.0%, respectively, p = 0.01). Ninety-minute ejection fraction and regional ventricular function were clinically similar in women and men with TIMI 2 or 3 flow (ejection fraction [mean ± SD]: 63.4 ± 6% vs. 59.4 ± 0.7%, p = 0.02; number of chords: 21.4 ± 0.9 vs. 21.0 ± 1.9, p = 0.7; SD/chord: −2.4 ± 08 vs. −2.4 ± 0.2, p = 0.9, respectively). No clinically significant differences in left ventricular function were noted at 5- to 7-day follow-up. Women had a greater hyperkinetic response than men in the noninfarct zone (SD/chord: 2.4 ± 0.2 vs. 1.7 ± 0.1, p = 0.005). The 30-day mortality rate was 13.1% in women versus 4.8% in men (p ≤ 0.0001). After adjustment for other clinical and angiographic variables, gender remained an independent determinant of 30-day mortality.Conclusions. Women do not differ significantly from men with regard to either early infarct-related artery patency rates or reocclusion after thrombolytic therapy or ventricular functional response to injury/reperfusion. Gender was an independent determinant of 30-day mortality after acute myocardial infarction.(J Am Coll Cardiol 1997;29:35–42)>

Angiographic Findings and Outcome in Diabetic Patients Treated With Thrombolytic Therapy for Acute Myocardial Infarction: The GUSTO-I Experience

This study sought to determine whether diabetes mellitus, in the setting of thrombolysis for acute myocardial infarction, affects 1) early infarct-related artery patency and reocclusion rates; and 2) global and regional ventricular function indexes. We also sought to assess whether angiographic or baseline clinical variables, or both, can account for the known excess mortality after myocardial infarction in the diabetic population. Mortality after acute myocardial infarction in patients with diabetes is approximately twice that of nondiabetic patients. It is uncertain whether this difference in mortality is due to a lower rate of successful thrombolysis, increased reocclusion after successful thrombolysis, greater ventricular injury or a more adverse angiographic or clinical profile in diabetic patients. Patency rates and global and regional left ventricular function were determined in patients enrolled in the GUSTO-I Angiographic Trial. Thirty-day mortality differences between those with and without diabetes were compared. The diabetic cohort had a significantly higher proportion of female and elderly patients, and they were more often hypertensive, came to the hospital later and had more congestive heart failure and a higher number of previous myocardial infarctions and bypass surgery procedures. Ninety-minute patency (Thrombolysis in Myocardial Infarction [TIMI] flow grade 3) rates in patients with and without diabetes were 40.3% and 37.6%, respectively (p = 0.7). Reocclusion rates were 9.2% vs. 5.3% (p = 0.17). Ejection fraction at 90 min after thrombolysis was similar in diabetic and nondiabetic patients ([mean +/- SEM] 6.10 +/- 1.6% vs. 60.1 +/- 0.7%, p = 0.7), as was regional ventricular function (number of abnormal chords: 19.1 +/- 2.0 vs. 17.5 +/- 0.8, p = 0.3; SD/chord: -2.3 +/- 0.2 vs. -2.4 +/- 0.1, p = 0.6). Diabetic patients had less compensatory hyperkinesia in the noninfarct zone (SD/ chord: 1.3 +/- 0.2 vs. 1.7 +/- 0.1, p < or = 0.01). No significant difference in ventricular function was noted at 5- to 7-day follow-up. The 30-day mortality rate was 11.3% in diabetic versus 5.9% in nondiabetic patients (p < or = 0.0001). After adjustment for clinical and angiographic variables, diabetes remained an independent determinant of 30-day mortality (p = 0.02). Early (90-min) infarct-related artery patency as well as regional and global ventricular function do not differ between patients with and without diabetes after thrombolytic therapy, except for reduced compensatory hyperkinesia in the noninfarct zone among patients with diabetes. Diabetes remained an independent determinant of 30-day mortality after correction for clinical and angiographic variables.