Complete Resolution Of ST-segment Elevation Research Articles

Predicting 30-Day Mortality Using ST-Segment Elevation Resolution in ST-Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention: An Indian Scenario.

The relationship between ST-segment elevation (STE) resolution and 30-day mortality has been evaluated, although limitedly, in non-Indian patients undergoing primary percutaneous coronary intervention (pPCI). We aimed to evaluate the prognostic utility of STE resolution in predicting 30-day mortality in Indian patients undergoing pPCI for ST-elevation myocardial infarction (STEMI). This prospective, single-center, observational study investigated the correlation between 30-day mortality rate and extent of STE resolution in real-world Indian patients undergoing pPCI for STEMI. A total of 64 patients underwent pPCI for STEMI at a tertiary care center in India. The patients were classified into three groups based on the extent of STE resolution: complete resolution (≥70%), partial resolution (30-70%), and no resolution (<30%). The primary endpoint of the study was occurrence of major adverse cardiovascular events consisting of all-cause death, reinfarction, disabling stroke, and ischemia-induced target vessel revascularization at 30 days follow-up. The study enrolled 56 patients. The mean age of patients was 59.7±6.8 years and there were 46 (82.1%) males. Complete STE resolution (≥70%) occurred in 7.1%, partial resolution (<70-30%) in 82.1% and no resolution (<30%) in 10.7%. The mortality rate was 2.1% and 33.3% in patients with partial and no STE resolution. No mortality was seen in patients with complete STE resolution. The 30-day survival analysis revealed significant differences between the three groups (P<0.01). STE resolution served as an independent predictor of 30-day mortality across all clinical variables, including patients with post-PCI thrombolysis in myocardial infarction (TIMI) 3 flow. Persistent STE after PCI is a reliable indicator of 30-day mortality in real-world STEMI patients. The extent of STE resolution can be used as a simple and affordable tool to stratify patients by the risk of mortality soon after the acute event. Due to their higher mortality at 30 days follow-up, individuals with persistent STE should be the focus for further treatment interventions.

Cardioprotective Effects of Coenzyme Q10 Supplementation on Patients with ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

Background: We assessed the potential efficacy of Coenzyme Q10 (CoQ10) in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). Methods: Seventy STEMI patients who presented ≤12 hours after the onset of symptoms and were scheduled for PPCI were randomly assigned to the standard treatments plus CoQ10 or placebo. In the intervention group, CoQ10, as an oral capsule at a dose of 400 mg, was loaded immediately before PPCI and continued at 200 mg twice daily for 28 days. The control group received a matching placebo, similarly. The study endpoints were the proportion of patients with complete myocardial reperfusion, defined as thrombolysis in myocardial infarction (TIMI) flow and myocardial blush grade (MBG) 3 at the end of PPCI, the proportion of patients with complete ST-segment elevation resolution (≥70%) assessed 60 minutes after PPCI, the plasma levels of creatine kinase myocardial band isoenzyme (CK-MB) and troponin I (TnI) at 12, 24, 48, and 72 hours after PPCI, and left ventricular ejection fraction (LVEF) at day 28. Results: The study groups were comparable regarding baseline clinical and procedural characteristics. The proportion of patients with TIMI flow grade 3, MBG 3, and complete ST resolution after completion of PPCI was similar between the groups. Whereas at all-time points after PPCI (12, 24, 48, and 72 hours), the plasma levels of CK-MB and TnI were significantly lower in the CoQ10 group than in the control group. Further, at day 28, CoQ10-treated patients exhibited better LVEF than placebo-treated patients, and the proportion of patients with LVEF less than 50% was lower in the intervention group than in the control group. Conclusion: Our study provided evidence that CoQ10 supplementation might reduce myocardial ischemia-reperfusion injury after PPCI and help to preserve left ventricular function. However, further studies are required to validate these results.

Glycoprotein IIb/IIIa inhibitors in combination with thrombus aspiration with, or without, stent implantation in patients presenting with S-T elevation myocardial infarction and high thrombus burden

Abstract Funding Acknowledgements Type of funding sources: None. Background High thrombus burden is an independent risk factor for death and complications, including no reflow, during primary percutaneous coronary intervention (PCI) for S-T elevation myocardial infarction (STEMI). Purpose To investigate whether a strategy of thrombus aspiration in combination with glycoprotein IIb/IIIa inhibitors without stent implantation is associated with a reduced incidence of slow- or no-reflow, and other thrombotic complications compared with stenting in patients with high thrombus burden. Methods A total of 210 patients with STEMI and high thrombus burden (thrombolysis in myocardial infarction thrombus grade ≥3) treated with thrombus aspiration in combination with glycoprotein IIb/IIIa inhibitors with or without stent implantation. Patients were divided into 2 groups: non-stent PCI group (deferred stenting, n = 105) and stent PCI group (immediate stenting, n = 105). A new catheterisation and deferred stent implantation was performed 48 - 72 hours after primary PCI. The end points were a myocardial blush grade of 0 or 1 (defined as absent or minimal myocardial reperfusion, respectively) and the postprocedural frequencies of a TIMI flow grade of 3, complete resolution of ST-segment elevation immediately after primary PCI, target vessel revascularization, reinfarction, death and the combination of major adverse cardiac events by 30 days after randomisation. Results A myocardial blush grade of 0 or 1 occurred in 26.3% of the patients in the stent PCI group and in 17.1% of those in the non-stent PCI group (p &amp;lt; 0.05). Complete resolution of ST-segment elevation occurred in 86.6% and 78.2% of patients, respectively (p = 0.35). At 30 days, the rate of death in the stent PCI group and non-stent PCI group was 1.7% and 1.0%, respectively (p = 0.33) and the rate of adverse events was 12.1% and 2.2%, respectively (p &amp;lt; 0.01). Conclusions Thrombus aspiration, in combination with glycoprotein IIb/IIIa inhibitors without immediate stenting, is an applicable and effective method in a large majority of patients with myocardial infarction with ST-segment elevation and a high thrombus burden.

1-Year Outcomes of Delayed Versus Immediate Intervention in Patients With Transient ST-Segment Elevation Myocardial Infarction

ObjectivesThe aim of the present study was to determine the effect of a delayed versus an immediate invasive approach on final infarct size and clinical outcome up to 1 year. BackgroundUp to 24% of patients with acute coronary syndromes present with ST-segment elevation myocardial infarction (STEMI) but show complete resolution of ST-segment elevation and symptoms before revascularization. Current guidelines do not clearly state whether these patients with transient STEMI should be treated with a STEMI-like or non–ST-segment elevation acute coronary syndrome–like intervention strategy. MethodsIn this multicenter trial, 142 patients with transient STEMI were randomized 1:1 to either delayed or immediate coronary intervention. Cardiac magnetic resonance imaging was performed at 4 days and at 4-month follow-up to assess infarct size and myocardial function. Clinical follow-up was performed at 4 and 12 months. ResultsIn the delayed (22.7 h) and the immediate (0.4 h) invasive groups, final infarct size as a percentage of the left ventricle was very small (0.4% [interquartile range: 0.0% to 2.5%] vs. 0.4% [interquartile range: 0.0% to 3.5%]; p = 0.79), and left ventricular function was good (mean ejection fraction 59.3 ± 6.5% vs. 59.9 ± 5.4%; p = 0.63). In addition, the overall occurrence of major adverse cardiac events, consisting of death, recurrent infarction, and target lesion revascularization, up to 1 year was low and not different between both groups (5.7% vs. 4.4%, respectively; p = 1.00). ConclusionsAt follow-up, patients with transient STEMI have limited infarction and well-preserved myocardial function in general, and delayed or immediate revascularization has no effect on functional outcome and clinical events up to 1 year.

Relationship between the ST-Segment Resolution and Microvascular Dysfunction in Patients Who Underwent Primary Percutaneous Coronary Intervention

Objectives Incomplete ST-segment elevation resolution (STR) occasionally occurs despite successful revascularization of epicardial coronary artery after primary percutaneous coronary intervention (PPCI). The aim of this study was to evaluate the relationship between the degree of STR and the severity of microvascular dysfunction. Methods A total of 73 consecutive patients with ST-segment elevation myocardial infarction (STEMI) who underwent successful PPCI were evaluated. Serial 12-lead electrocardiography was performed at baseline and at 90 minutes after PPCI. Microvascular dysfunction was assessed by index of microvascular resistance (IMR) immediately after PPCI. Results Patients were classified into 2 groups: 50 patients with complete STR (STR ≥50%) and 23 patients with incomplete STR (STR <50%). The incomplete STR group had a higher IMR value and lower left ventricular ejection fraction (LVEF), compared with the complete STR group. The degree of STR was significantly correlated with IMR (r = −0.416, P=0.002) and LVEF (r = 0.300, P=0.011). These correlations were only observed in patients with left anterior descending artery (LAD) infarction but not observed in patients with non-LAD infarction. A cutoff IMR value was 27.3 for predicting incomplete STR after PPCI. Conclusion Incomplete STR after PPCI in patients with STEMI reflects the presence of microvascular and left ventricular dysfunction, especially in patients with LAD infarction.

Contemporary therapy of intracoronary thrombus: laser and bioresorbable scaffold

A 25-year-old diabetic, smoker presented with an acute anterior ST-segment elevation myocardial infarction. Immediate coronary angiography demonstrated an occluded left anterior descending artery (LAD) with large proximal thrombus burden. Simple aspiration catheter thrombectomy restored some antegrade flow but was unsuccessful in removing the thrombus (Fig. 1a). Photoablation using excimer laser coronary atherectomy (ELCA) was more effective in debulking the thrombus and restored TIMI 3 blood flow (Fig. 1c). Optical coherence tomography (OCT) clarified that the atherothrombotic material was localised without distal or proximal thin-cap fibroatheroma in the LAD (Fig. 1b). A bioresorbable vascular scaffold (BVS) was deployed and post dilated (Fig. 1d, e) with full expansion demonstrated with OCT (Fig. 1f, g) resulting in complete resolution of ST-segment elevation and symptoms. He made an excellent recovery and left hospital on day 3 post MI. He has subsequently returned to a full, active life. This case highlights both the effectiveness of ELCA in treating massive intracoronary thrombus and use of BVS to avoid long-term residual metallic stent in a young patient with coronary heart disease embarking on their revascularisation journey.

Cardioprotective Effects of Oral Trimetazidine in Diabetic Patients With Anterior Wall Myocardial Infarction Treated with Thrombolysis.

BackgroundTrimetazidine is an anti-ischemic agent with anti-oxidant activity. This study sought to evaluate the impact of oral trimetazidine on extent of myocardial damage in diabetic patients who were presented with anterior wall ST-segment elevation myocardial infarction (STEMI).MethodsOne hundred patients were prospectively enrolled, and then randomly assigned to receive oral trimetazidine (70 mg then 35mg bid) (group A, 50 patients) or placebo (group B, 50 patients), starting before thrombolysis. Serum creatine kinase-T and MB (CK-T and CK-MB) were measured serially. Degree of ST-segment resolution was recorded after 90 minutes. Left ventricle ejection fraction (LVEF) was assessed at baseline and after 6 months. Adverse events were recorded after thrombolysis and 6 months later.ResultsMean age of the study cohort was 59.05 ± 3.8 years (males: 60%). After 24 hours, 45 (90%) patients in group A vs. 10 (20%) patients in group B showed peaking of CK-T and CK-MB levels (P < 0.05). Both biomarkers’ levels were significantly higher in the placebo group at different sampling times. Complete resolution of ST-segment elevation was recorded in 35 (70%) patients in group A vs. 18 (36%) patients in group B (P < 0.05). Six months later, group A showed higher LVEF and fewer cardiac adverse events (P < 0.05).ConclusionIn diabetic patients receiving thrombolytic therapy for anterior wall STEMI, oral trimetazidine dosing was associated with less myocardial damage, earlier successful reperfusion, improvement of LVEF and less cardiac adverse events.

The randomized physiologic assessment of thrombus aspirtion in patients with ST-segment Elevation acute Myocardial Infarction trial (PATA STEMI)

Background: Routine thrombus aspiration is superior to conventional primary Percutaneous Coronary Intervention (PCI) in terms of improved myocardial perfusion in patients with acute myocardial infarction with ST-segment Elevation (STEMI). However, myocardial perfusion after thrombus aspiration has not been evaluated by a quantitative Index of Microcirculatory Resistance (IMR). Methods: We performed a randomized, controlled clinical trial to evaluate impact of manual thrombus aspiration (the Eliminate aspiration catheter, Terumo Medical Supply, Japan) on microcirculatory resistance after primary PCI in 128 patients with the first STEMI randomly assigned to thrombus aspiration or conventional primary PCI group before coronary angiography. The primary endpoint was defined as a significant reduction of IMR in thrombus aspiration compared to conventional PCI group. Myocardial perfusion grade and resolution of ST-segment elevation were also assessed. Infarct size and left ventricle remodeling were assessed by echocardiographic indices. Results: Manual thrombus aspiration, as compared with conventional PCI, resulted in significantly lower IMR (31.9±21.3 U vs. 47.0±35.8 U, P = 0.0082). Treatment with thrombus aspiration, as compared with conventional PCI, resulted in similar rates of myocardial perfusion grade 0 or 1 (20.8% vs. 29.4%; relative risk, 0.71; 95% CI, 0.38 to 1.30; P=0.26) and complete resolution of ST-segment elevation (59.7% vs. 47.1%; relative risk, 1.27; 95% CI, 0.90 to 1.79, P=0.17). In a multiple regression model with the log-transformed IMR as dependent variable, after adjusting for clinical, angiographic and procedural variables, thrombus aspiration remained a strong independent predictor of lower IMR (27.14 U; 95% CI, 23.79 to 30.95 U, vs. 36.11 U; 95% CI, 30.74 to 42.41 U, P=0.0076). Histopathological examination confirmed successful thrombus aspiration in 89.6% of patients. The results of echocardiographic analysis will be available at the time of the presentation. Conclusions: Manual thrombus aspiration reduces microcirculatory resistance indicating better myocardial perfusion compared to conventional PCI in patients with STEMI.

Complete Resolution of ST-Segment Elevation Due to Reversal of Pre-Existing Collateral Flow

![Figure][1] [![Graphic][3] ][3][![Graphic][4] ][4] A 50-year-old man presented to emergency department with chest pain for 1 h. Electrocardiogram noted an ST-segment elevation in the inferior leads (A) , which resolved completely 15 min later when the patient's symptoms subsided

Vaporizing Thrombus With Excimer Laser Before Coronary Stenting Improves Myocardial Reperfusion in Acute Coronary Syndrome

Mechanical reperfusion has proven to be an unquestionably superior treatment strategy over that of thrombolytic therapy in patients with acute coronary syndrome (ACS). Excimer laser coronary angioplasty (ELCA) is a unique revascularization device that has a lytic effect on thrombus, in addition to its debulking effect on the atherosclerotic plaque beneath the thrombus. This single-center retrospective analysis consisted of consecutive ACS patients treated with ELCA (n=50) and age- and sex-matched ACS patients treated with manual aspiration (n=48) without use of a distal protection device. Success rate was judged by lesion crossability, procedure complications, and significant reduction of stenosis. Tissue-level perfusion was assessed on antegrade Thrombolysis In Myocardial Infarction (TIMI) flow grade, myocardial blush grade (MBG), and ST-segment elevation resolution (STR). Short-term outcome was evaluated according to occurrence of in-hospital major adverse cardiac events (MACE; myocardial infarction, target lesion revascularization, coronary artery bypass graft, and death). Lesion crossability was higher in the ELCA group than in the aspiration group (96.2% vs. 82.6%, P=0.04). Attainment of TIMI 3 flow (86.0% vs. 68.8%, P=0.04) and MBG 3 (76.0% vs. 54.2%, P=0.02) was also higher in the ELCA group than in the aspiration group. Complete STR was similar between the 2 groups. In-hospital MACE were significantly more frequent in the aspiration group. ELCA is feasible, safe, and effective for the treatment of patients with ACS and appears to be useful as an adjunctive lesion preparation device.

Prehospital Abciximab in ST-Segment Elevation Myocardial Infarction

The value of prehospital initiation of glycoprotein IIb/IIIa inhibitors remains a controversial issue. We sought to investigate whether in-ambulance initiation of abciximab in patients with ST-segment elevation myocardial infarction (STEMI) improves ST-segment elevation resolution (STR) after primary percutaneous coronary intervention (PCI). MISTRAL (Myocardial Infarction with ST-elevation Treated by Primary Percutaneous Intervention Facilitated by Early Reopro Administration in Alsace) is a prospective, randomized, double-blind study. Two hundred and fifty-six patients with acute STEMI were allocated to receive abciximab either in the ambulance (ambulance group, n=127) or in the catheterization laboratory (hospital group, n=129). The primary end point was complete (>70%) STR after PCI. Complete STR was not significantly different between the 2 groups (before PCI, 21.6% versus 15.5%, P=0.28; after PCI, 70.3% versus 65.8%, P=0.49). Thrombolysis In Myocardial Infarction (TIMI) 2 to 3 flow rates before PCI tended to be higher in the ambulance group (46.8% versus 35%, P=0.08) but not after PCI (70.3% versus 65.8%, P=0.49). Slow flow tended to be lower (5.6% versus 13.4%, P=0.07), and distal embolization occurred significantly less often in the ambulance group (8.1% versus 21.1%, P=0.008). One- and 6-month major adverse cardiac event rates were low and similar in both groups. Early ambulance administration of abciximab in STEMI did not improve either STR or TIMI flow rate after PCI. However, it tended to improve TIMI flow pre-PCI and decreased distal embolization during procedure. Larger studies are needed to confirm these results.

Delivery of Glycoprotein IIb/IIIa Inhibitor Therapy for Percutaneous Coronary Intervention

A major goal of any antithrombotic regimen administered during percutaneous coronary intervention (PCI) is the preservation of coronary microvascular perfusion, which is critical for myocardial survival. In addition to macrovascular thrombosis, microembolization into the downstream coronary artery bed that occurs during spontaneous plaque rupture and PCI plays a prominent role in the development of microvascular dysfunction that leads to myocardial infarction. In addition to physical obstruction of the lumen by the embolus, vasoconstriction and edema due to inflammation also impair microvascular flow.1 These events likely occur more frequently during PCI performed in the setting of unstable coronary syndromes.2 With Doppler guidewire technology, it was estimated that an average of 25 embolic events occurred during primary PCI for ST-segment elevation myocardial infarction.3 Article see p 784 Platelet aggregates are important components of coronary microemboli, along with leukocytes, erythrocytes, platelet-leukocyte aggregates, cholesterol crystals, and hyalin. Platelets and leukocytes within microemboli play a particularly important role in the pathophysiological changes of blood flow by promoting in situ microvascular thrombosis, vasoconstriction, and inflammation. Interestingly, the composition of the embolized material is similar in the settings of spontaneous and catheter-induced plaque rupture.1 In animal models, distal microembolization of inert microspheres is associated with an immediate reduction in flow due to vessel occlusion, followed by enhanced blood flow due to the effects of adenosine released from the embolized myocardium into the adjacent noninvolved myocardium.4 Microembolization results in overall reduced flow reserve and the progressive loss of contractile function, which often reverses within weeks. The degree of myocardial contractile dysfunction is disproportionate to the degree of infarction and is the result of inflammation.5 However, in the clinical condition, a more complex pathophysiology exists due to the influence of multiple components of the emboli. Platelets aggregate when fibrinogen binds to the active …

Thrombus Aspiration during Primary Percutaneous Coronary Intervention

Primary percutaneous coronary intervention (PCI) is effective in opening the infarct-related artery in patients with myocardial infarction with ST-segment elevation. However, the embolization of atherothrombotic debris induces microvascular obstruction and diminishes myocardial reperfusion. We performed a randomized trial assessing whether manual aspiration was superior to conventional treatment during primary PCI. A total of 1071 patients were randomly assigned to the thrombus-aspiration group or the conventional-PCI group before undergoing coronary angiography. Aspiration was considered to be successful if there was histopathological evidence of atherothrombotic material. We assessed angiographic and electrocardiographic signs of myocardial reperfusion, as well as clinical outcome. The primary end point was a myocardial blush grade of 0 or 1 (defined as absent or minimal myocardial reperfusion, respectively). A myocardial blush grade of 0 or 1 occurred in 17.1% of the patients in the thrombus-aspiration group and in 26.3% of those in the conventional-PCI group (P<0.001). Complete resolution of ST-segment elevation occurred in 56.6% and 44.2% of patients, respectively (P<0.001). The benefit did not show heterogeneity among the baseline levels of the prespecified covariates. At 30 days, the rate of death in patients with a myocardial blush grade of 0 or 1, 2, and 3 was 5.2%, 2.9%, and 1.0%, respectively (P=0.003), and the rate of adverse events was 14.1%, 8.8%, and 4.2%, respectively (P<0.001). Histopathological examination confirmed successful aspiration in 72.9% of patients. Thrombus aspiration is applicable in a large majority of patients with myocardial infarction with ST-segment elevation, and it results in better reperfusion and clinical outcomes than conventional PCI, irrespective of clinical and angiographic characteristics at baseline. (Current Controlled Trials number, ISRCTN16716833.)

Aspiration Thrombectomy of a Massive Thrombotic Embolus in Acute Myocardial Infarction Caused by Coronary Embolism

Coronary embolism is one of the less common causes of acute myocardial infarction (AMI). We describe a 72-year-old man with atrial fibrillation having an AMI, in whom a massive intracoronary thrombus of the right coronary artery was successfully removed by aspiration via a thrombectomy catheter, achieving successful reperfusion with a complete resolution of ST-segment elevation. The appearance of the aspirated material suggested coronary embolism was the cause of the AMI. It is concluded aspiration thrombectomy is a feasible and safe approach for treating coronary embolism.

The role of thrombectomy and embolic protection devices

In recent years, it has been demonstrated that restoration of normal coronary flow in the infarct-related artery is not equivalent to the restoration of myocardial perfusion through cardiac microcirculation. Among patients with ST-segment elevation myocardial infarction (STEMI) who undergo primary percutaneous coronary intervention (PCI), distal embolization and slow-flow and no-flow phenomenon occur in ∼30% of patients. In these patients, PCI results are less satisfactory, with lower thrombolysis in myocardial infarction (TIMI) or myocardial blush grade (MBG) values, lower rate of a complete resolution of ST-segment elevation, lower left ventricular ejection fraction, and poorer long-term outcome. Studies investigating the usefulness of thrombectomy systems in STEMI showed a similar proportion of patients with TIMI (flow grade 3) in the infarct-related artery in thrombectomy treated patients and control groups. Some small studies with thrombectomy systems or distal protection devices showed encouraging results with preventing slow-flow, no-reflow, and distal embolization, as measured by improved myocardial perfusion by angiography and improved ST-segment elevation resolution after PCI. Large, multi-centre studies did not confirm clinical benefit. New European Society of Cardiology PCI guidelines do not give definitive recommendations regarding the use of embolic protection devices for this group of patients. More randomized trials are needed. However, thrombectomy may be very effective in the situation of large thrombus bulk when present after first balloon catheter inflation. It could be also potentially effective with easy to use thrombectomy system for replacing balloon pre-dilatation before stenting, if studies could prove clinical benefit of such concept for primary PCI.

Tenecteplase and tirofiban in ST-segment elevation acute myocardial infarction: Results of a randomized trial

The combination of older reduced-dose fibrinolytic agents and platelet glycoprotein IIb/IIIa inhibitors has shown modest improvements in reperfusion and more striking improvements in ST-segment resolution after acute myocardial infarction. We performed a multicenter dose-ranging study of reduced doses of a newer fibrinolytic (tenecteplase) combined with tirofiban, a glycoprotein IIb/IIIa inhibitor. The first goal of the trial was to identify a dose or doses of tirofiban that, when combined with reduced-dose tenecteplase, would result in a higher incidence of Thrombolysis In Myocardial Infarction (TIMI) grade 3 flow at 60 minutes versus full-dose tenecteplase alone. The second goal was to assess whether the optimum dose(s) from the first stage also would result in greater resolution of ST-segment elevation. In all, 409 patients aged 18 to 75 years with myocardial infarction were enrolled. The incidence of TIMI grade 3 flow at 60 minutes did not differ significantly among dose groups, ranging from 50% to 68%. The corrected TIMI frame count likewise did not differ substantially (range 34-42). More patients given combined therapy had complete resolution of ST-segment elevation at 60 minutes compared with patients given tenecteplase alone. Major bleeding was infrequent, and no strokes occurred. Based on angiographic results of the first stage, the second planned stage of the study was not performed. Although combination therapies were not associated with increased reperfusion compared with full-dose tenecteplase alone, similar TIMI flow grades were achieved despite reductions in tenecteplase doses. ST-segment resolution was more rapid and complete with combination therapy versus full-dose tenecteplase, suggesting enhanced microcirculatory perfusion to the infarct zone in this dose-ranging trial.

Impact of ST-segment depression resolution on mortality after successful mechanical reperfusion in patients with ST-segment elevation acute myocardial infarction

The aim of the present study was to evaluate the additional prognostic effect of ST-depression resolution in 610 patients who had ST-elevation myocardial infarction and underwent successful primary angioplasty (postprocedural Thrombolysis In Myocardial Infarction 3 flow and complete resolution of ST-segment elevation). Incomplete resolution of ST-segment depression (<70%) was observed in 50 patients (8.2%). These patients were older, had a higher Killip's class at presentation, had larger infarcts, and had an increased 1-year mortality (10% vs 2%, p = 0.0004). At multivariate analysis, incomplete resolution of ST-segment depression was an independent predictor of 1-year mortality (p = 0.028).

Prognostic significance of ST segment change in acute myocardial infarct

The extent of ST segment elevation resolution (STR) 180 minutes after initiation of streptokinase treatment for acute myocardial infarction within 6 hours after onset of symptoms is an excellent early prognostic indicator that can be easily determined in all patients. This presentation is based on a meta-analysis from 3 thrombolysis studies including 3,912 patients. About 50% of patients had complete STR (> or = 70%). They had small enzymatic infarct sizes and well preserved left ventricular function associated with an excellent chance of survival. Patients with partial STR (< 70 to 30%) developed larger infarcts, but had still a relatively low mortality. To assess the optimal cut-off point that best predicts an increased mortality risk, the squared standardized log odds ratio statistics as a function of the hypothetical cut-off points in STR was used. A cut-off point around 30% STR was associated with an extraordinarily strong predictive power. The 35-day cardiac mortality with STR < 30% was 12.7% as compared to 2.1% for patients who had complete STR and 4.2% for those who had partial STR. Based on STR, age, medical history, and simple parameters at admission, a low risk population can be defined that includes about 50% of all patients aged < or = 70 years, and 20% of older patients. The 35-day and 1-year mortality rates for the group of younger patients was 1.4% and 2.7%, respectively, and for the older age group 5.0% and 7.9%. It appears highly unlikely that aggressive testing and interventions would have any measurable beneficial effect on such a good outcome. In thrombolytic therapy comparative trials STR may perform well as a surrogate endpoint, since it is more powerful than 90 minutes post-thrombolytic patency rates and early mortality, in a statistical sense. This is especially true for Phase-II dose-finding studies and the use as a surrogate or even primary endpoint in phase-III trials. In addition, STR may be very helpful for safety monitoring, interim analyses, and subgroup analyses in megatrials with the endpoint mortality. Use of STR can result in a substantial reduction in the required sample size. However, at least 1 pivotal mortality trial cannot be replaced by STR trials, since STR does not reflect the risk of intracranial hemorrhages and other bleeding complications.

High frequency QRS electrocardiography in the detection of reperfusion following thrombolytic therapy.

The hypothesis that an increase in the amplitude (root-mean-square voltage) of the high frequency (150-250 Hz) components of the QRS complex occurs with successful reperfusion following thrombolytic therapy in acute myocardial infarction (AMI) and fails to occur when thrombolysis fails was tested. Clinical markers for successful or failed reperfusion following thrombolytic therapy for AMI are notoriously insensitive. The amplitude of the high-frequency components of the QRS complex decreases during ischemia and returns to normal with resolution of ischemia, but neither the variability in measurement of these potentials nor their patterns of change during the course of AMI have been described. In 32 control subjects, the average coefficient of variation for the amplitude of the high-frequency QRS complex was 10% or 0.3 uV. Based on these data, for the acute infarction population a significant change in this measurement was therefore defined as a change in amplitude > 20% or 0.6 uV on two consecutive recordings. In 30 patients with AMI treated with a thrombolytic agent, either cardiac catheterization, serial serum myoglobin, or complete resolution of ST-segment elevation were used to define successful or failed reperfusion. High-frequency QRS electrocardiograms were obtained at the start of treatment with a thrombolytic agent and for 3 h thereafter using a signal-averaging technique and digital filtering. Standard 12-lead electrocardiograms were obtained at the same time. In patients who reperfused successfully, the high-frequency QRS amplitude increased significantly (1.2 +/- 0.9 uV above its nadir at 83 +/- 36 min after initiation of thrombolytic therapy) in 23 of 25 patients.(ABSTRACT TRUNCATED AT 250 WORDS)