Incomplete recanalization as an important determinant of Thrombolysis in Myocardial Infarction (TIMI) grade 2 flow after thrombolytic therapy for acute myocardial infarction. TEAM Investigators. Thrombolytic Trial of Eminase in Acute Myocardial Infarction

Correlation Between Distal Left Anterior Descending Artery Flow Velocity by Transthoracic Doppler Echocardiography and Corrected TIMI Frame Count Before Mechanical Reperfusion in Patients With Anterior Acute Myocardial Infarction

BACKGROUND

This study was designed to determine the utility of transthoracic Doppler echocardiography (TTDE) in evaluating angiographic Thrombolysis in Myocardial Infarction (TIMI) frame count as a quantitative index of coronary reperfusion in patients with anterior acute myocardial infarction (AMI) before mechanical reperfusion.

METHODS AND RESULTS

Color and pulsed TTDE was performed to evaluate distal left anterior descending coronary artery (LAD) reperfusion in 56 consecutive patients with a first anterior AMI before coronary intervention, and these findings were compared with the corrected TIMI frame count (cTFC) by subsequent angiography. Twenty-four of the 56 patients had LAD reperfusion (TIMI 2 or 3) by angiography. Visual antegrade distal LAD flow by color TTDE was detected in 21 of these 24 patients. In the 21 patients, diastolic peak velocity of the distal LAD flow by pulsed TTDE showed a significant correlation with cTFC by angiography (r = -0.74, p < 0.001). The diagnosis of high risk with angiographic cTFC >40 by distal LAD peak velocity <21 cm/s using TTDE had a sensitivity, specificity, and accuracy of 82%, 93%, and 91%, respectively.

CONCLUSION

TTDE enables noninvasive and quantitative evaluation of distal LAD reperfusion in patients with anterior AMI in the acute phase before mechanical reperfusion.

C-Reactive protein on admission and the success of thrombolytic therapy with streptokinase: is there any relation?

BACKGROUND

Recent evidence has demonstrated that inflammation plays a major role in the initiation and progression of atheroma plaques. C-reactive protein (CRP) is shown to have prognostic significance in acute coronary syndromes. We investigated the influence of CRP levels before thrombolytic therapy on infarct-related artery (IRA) patency and the degree of residual stenosis.

METHODS

45 consecutive patients with a first attack of acute myocardial infarction (MI) who underwent streptokinase therapy and subsequently coronary angiography were enrolled into the study. Patients were divided into 2 groups according to the level of CRP on admission.

RESULTS

Serum CRP levels were > or =0.5 mg/dL in 26 patients (Group-I) and <0.5 mg/dL in 19 patients (Group-II). The patency of IRA (TIMI-2 and 3) evaluated at 90th minute after the initiation of thrombolytic therapy was similar between the two groups (62% vs. 68%, p>0.05). However, the presence of TIMI-3 flow was significantly lower and TIMI-2 flow was higher in Group-I as compared to Group-II (12% vs. 53%, p=0.003 and 50% vs. 16%, p=0.018 respectively). Additionally, among patients with patent IRA, the degree of residual stenosis was significantly higher in Group-I (80 +/- 14% vs. 68 +/- 15%, p=0.032).

CONCLUSION

High serum CRP levels on admission in patients within 6 hours after the start of acute ST-segment elevation MI are associated with lower TIMI flow grades and higher residual stenosis of IRA after intravenous streptokinase. Our observations imply that patients with higher CRP levels on admission require closer follow-up during and after acute MI.

Significance of thrombolysis in myocardial infarction (TIMI) grade 2 flow early after thrombolysis followed by immediate percutaneous coronary intervention in patients with acute myocardial infarction

Although pre-interventional thrombolysis has recently been shown to restore early patency and preserve left ventricular function in patients with acute myocardial infarction, the significance of Thrombolysis in Myocardial Infarction (TIMI) grade flow early after thrombolysis remains unclear. Patients were classified into 3 groups according to TIMI grade flow 45 min after thrombolysis; 38 patients with TIMI grade 0 or 1 flow (group T0) and 46 with TIMI grade 2 flow (group T2) additionally received immediate percutaneous coronary intervention (PCI) and 50 patients with TIMI grade 3 flow (group T3) were treated conservatively after thrombolysis. Although the door-to-balloon times did not differ in groups T0 and T2, group T2 had lower peak creatine kinase, a higher rate of complete (>/=70%) ST resolution and better regional wall motion at discharge as compared with group T0, similar to group T3 (group T2, group T3 vs group T0; 2,857+/-1,756, 2,314+/-1,948 vs 3,779 +/-2,214 mU/ml; 57, 72 vs 34%; -1.5+/-1.6, -1.2+/-1.6 vs -2.2+/-1.6; all p<0.01, respectively). These results suggest TIMI grade 2 flow at 45 min after thrombolysis followed by immediate PCI, as well as TIMI grade 3 flow, is associated with greater myocardial salvage than TIMI grade 0 or 1 flow.

Determinants of coronary blood flow after thrombolytic administration. TIMI Study Group. Thrombolysis in Myocardial Infarction

OBJECTIVES

This study evaluated the determinants of coronary blood flow following thrombolytic administration in a large cohort of patients.

BACKGROUND

Tighter residual stenoses following thrombolysis have been associated with slower coronary blood flow, but the independent contribution of other variables to delayed flow has not been fully explored.

METHODS

The univariate and multivariate correlates of coronary blood flow at 90 min after thrombolytic administration were examined in a total of 2,195 patients from the Thrombolysis in Myocardial Infarction (TIMI) 4, 10A, 10B and 14 trials. The cineframes needed for dye to first reach distal landmarks (corrected TIMI frame count, CTFC) were counted as an index of coronary blood flow.

RESULTS

The following were validated as univariate predictors of delayed 90-min flow in two cohorts of patients: a greater percent diameter stenosis (p < 0.0001 for both cohorts), a decreased minimum lumen diameter (p = 0.0003, p = 0.0008), a greater percent of the culprit artery distal to the stenosis (p = 0.03, p = 0.02) and the presence of any of the following: delayed achievement of patency (i.e., between 60 and 90 min) (p < 0.0001 for both cohorts), a culprit location in the left coronary circulation (left anterior descending or circumflex) (p = 0.02, p < 0.0001), pulsatile flow (i.e., reversal of flow in systole, a marker of heightened microvascular resistance, p = 0.0003, p < 0.0001) and thrombus (p = 0.002, p = 0.03). Despite a minimal 16.4% residual stenosis following stent placement, the mean post-stent CTFC (25.8 +/- 17.2, n = 181) remained significantly slower than normal (21.0 +/- 3.1, n = 78, p = 0.02), and likewise 34% of patients did not achieve a CTFC within normal limits (i.e., <28 frames, the upper limit of the 95th percent confidence interval previously reported for normal flow). Those patients who failed to achieve normal CTFCs following stent placement had a higher mortality than did those patients who achieved normal flow (6/62 or 9.7% vs. 1/118 or 0.8%, p = 0.003).

CONCLUSIONS

Lumen geometry is not the sole determinant of coronary blood flow at 90 min following thrombolytic administration. Other variables such as the location of the culprit artery, the duration of patency, a pulsatile flow pattern and thrombus are also related to slower flow. Despite a minimal 16% residual stenosis, one-third of the patients treated with adjunctive stenting still have a persistent flow delay following thrombolysis, which carries a poor prognosis.

Evolution of early TIMI 2 flow after thrombolysis for acute myocardial infarction. GUSTO-1 Angiographic Investigators

BACKGROUND

Patients with early Thrombolysis in Myocardial Infarction (TIMI) grade 2 flow after thrombolysis appear to have outcomes similar to thrombolytic failures. To evaluate the origin and evolution of early TIMI 2 flow, we examined early and late angiographic and ventriculographic data from the Global Utilization of Streptokinase and TPA for Occluded Arteries (GUSTO-1) angiographic study.

METHODS AND RESULTS

Of the 914 patients with both 90-minute and 5- to 7-day catheterizations, 278 patients had TIMI grade 2 flow at 90 minutes. At follow-up, 188 (67%) had improved to TIMI grade 3 flow. At 90 minutes, patients with TIMI grade 2 flow had greater infarct vessel narrowing and a significantly greater incidence of thrombus than patients with TIMI grade 3 flow. At the 5- to 7-day follow-up, patients whose flow had improved from TIMI grade 2 at 90 minutes to grade 3 flow at follow-up had larger-caliber vessels (minimum luminal diameter, 0.99 +/- 0.47 versus 0.84 +/- 0.48 mm; P = .03) and a lower incidence of visible thrombus (26% versus 38%, P = .04) than those with persistent TIMI grade 2 flow. These patients also had a higher mean ejection fraction (57.5 +/- 14.1% versus 52.8 +/- 12.9%, P = .02) and better infarct zone wall motion (-2.1 +/- 1.5 versus -2.6 +/- 1.3 SD per chord, P = .01) at the 5- to 7-day follow-up. Patients in whom flow improved from TIMI grade 2 at 90 minutes to TIMI grade 3 by 5 to 7 days had significantly better left ventricular function than patients with persistent TIMI grade 0, 1, or 2 flow and constituted a group whose left ventricular function was intermediate between those who had no reperfusion (TIMI grades 0 and 1) and those whose reperfusion was complete (TIMI grade 3).

CONCLUSIONS

These data suggest that incomplete clot lysis plays a significant role in the pathogenesis of TIMI grade 2 flow. Furthermore, early TIMI grade 2 flow may be sufficient to provide prolonged myocyte viability, which will further recover if flow normalizes.

Metaanalysis of five reported studies on the relation of early coronary patency grades with mortality and outcomes after acute myocardial infarction

Coronary patency has been used as a measure of thrombolysis success after acute myocardial infarction (AMI). The Thrombolysis in Myocardial Infarction (TIMI) study grading scale for coronary perfusion has gained wide acceptance, but the significance of individual grades on clinical outcome has not been adequately tested. We hypothesized that optimal outcomes would be achieved only with early (and maintained) TIMI grade 3 (complete) perfusion compared with TIMI grade 2 (partial perfusion, previously classified as a reperfusion success) or grades 0 or 1 (occluded arteries). Five recent, angiographically controlled, prospectively performed studies of thrombolysis in AMI were identified, representing 3,969 patients. Odds ratios for mortality by early perfusion grades were calculated using the Mantel-Haenszel test and combined in a weighted fashion. Results for selected clinical and laboratory outcomes by patency grade were also assessed. Overall, mortality averaged 8.8% for TIMI grade 0/1, 7.0% for grade 2, and 3.7% for grade 3 perfusion. The odds ratio (OR) for early mortality was substantially reduced for grade 3 versus <3 perfusion (OR = 0.45, confidence interval [CI] 0.34 to 0.61, p <0.0001). In pairwise comparisons, grade 3 was clearly superior to grade 2 (OR = 0.54, CI) 0.37 to 0.78, p = 0.001) as well as grades 0/1 (OR = 0.41, CI 0.30 to 0.56, p <0.0001). Acute and convalescent ejection fraction, regional wall motion, time to enzyme peaks (creatine kinase [CK], creatine kinase myocardial bond [CK-MB]), peak enzyme levels [CK, lactate dehydrogenase [LDH], LDH-1), and risk of heart failure were each significantly less in patients achieving grade 3 than grade 2 (or lower grades) perfusion. Results were observed despite the frequent use of interventions after angiography. This meta-analysis demonstrates that early and complete (grade 3) flow is associated with superior survival and clinical outcome; grade 2 perfusion results in an inferior outcome, closer to that of an occluded than an open artery. The goal of reperfusion strategies should be early and maintained TIMI grade 3 perfusion.