TIMI Grade Research Articles

Right Ventricular Dysfunction After Thrombolysis in Patients with Right Ventricular Infarction

Background: Right ventricular (RV) infarction is frequently associated with highest risk of death and major complications. Doppler echocardiography can be useful in the diagnosis of RV involvement. The goal of this study was to evaluate Doppler echocardiography features associated with RV involvement and a poor prognosis. Methods: Two-dimensional Doppler echocardiography was performed before and after thrombolysis in 108 consecutive patients with an RV infarction. The bedside examination was performed before and 2 to 3 hours after thrombolytic therapy, and repeated after 1 and 7 days. All patients underwent coronary angiography after 20 days, and the perfusion of the coronary-related artery (> thrombolysis in myocardial infarction [TIMI] 3 grade) was evaluated. Results: Patients were divided into 2 groups according to the recovery of global and regional RV function after thrombolytic therapy. In the group of patients who showed a normalization or improvement of RV wall motion (as assessed by RV wall motion score index), we found a TIMI grade III perfusion in 78% of patients. The analysis of interatrial septal motion and interventricular septal motion showed a normalization in all reperfused patients. Major complication and deaths were more frequent in patients with echocardiographic findings of RV dysfunction persisting after thrombolytic therapy. Conclusion: In patients with RV infarction treated with thrombolysis, persistent RV dysfunction is associated with a higher risk for the development of major cardiac complications and death. (J Am Soc Echocardiogr 2000;13:655-60.)

Heart-Type Fatty Acid Binding Protein as a marker of reperfusion after thrombolytic therapy

Accurate, rapid, and simple noninvasive measures of infarct-related artery (IRA) patency are needed to identify patients with failed coronary reperfusion for rescue percutaneous coronary intervention (PCI). Heart-type Fatty Acid Binding Protein (H-FABP) is a small, cytosolic protein found in high concentrations in the myocardium. We evaluated the efficacy of H-FABP as a marker for successful reperfusion after thrombolysis. Fifty-eight subjects from the TIMI 14 trial had H-FABP and myoglobin concentrations measured at baseline (immediately prior to thrombolysis) and 60, 90, and 180 min after thrombolysis. All patients underwent coronary angiography at 90 min. By 60 min after thrombolysis, median concentrations of H-FABP and myoglobin were significantly higher in patients with a patent IRA than in those with an occluded IRA ( P<0.01 for each). Similarly, the 60 and 90 min/baseline H-FABP and myoglobin ratios were significantly higher among patients with a patent IRA ( P<0.01 for each). There were no significant differences in marker concentrations or ratios between patients with TIMI grade 2 and TIMI grade 3 flow. The area under the ROC curve tended to be greater for the 60 and 90 min/baseline myoglobin ratios than for similar ratios of H-FABP (0.71 and 0.73 vs. 0.64 and 0.62; P=ns). In conclusion, successful reperfusion can be detected within the first 60 min after thrombolysis with either H-FABP or myoglobin. Despite a favorable kinetic profile, however, H-FABP does not appear to represent a significant advance over myoglobin in the noninvasive detection of reperfusion after thrombolysis.

Noninvasive, transthoracic, low-frequency ultrasound augments thrombolysis in a canine model of acute myocardial infarction.

Limitations of coronary thrombolysis include the time to reperfusion, patency rate, and bleeding. We evaluated the use of noninvasive transcutaneous ultrasound to augment coronary thrombolysis. In 24 dogs, a thrombotic occlusion of the left anterior descending coronary artery was induced and documented by 12-lead ECG and coronary angiography. After >/=60 minutes of occlusion, tissue-type plasminogen activator (t-PA; 1.42 mg/kg) was given intravenously over 90 minutes. A total of 12 of the 24 dogs had concomitant transcutaneous application of low-frequency ultrasound (27 kHz) over the chest. At 90 minutes, the mean TIMI grade flow in the t-PA alone group was 0.92+/-1.4 compared with 2. 42+/-1.9 in the t-PA plus ultrasound group (P=0.006). TIMI 2 to 3 flow was present in 4 of 12 cases receiving t-PA alone compared with 10 of 12 cases receiving t-PA plus ultrasound (P=0.003). At 180 minutes, mean TIMI grade flow was 0.75+/-1.4 in the t-PA alone group versus 2.58+/-0.9 in the t-PA plus ultrasound group (P=0.001). Pathological examination confirmed the angiographic patency rate and did not reveal injury secondary to ultrasound in the skin, soft tissues, heart, or lungs. In vivo, the noninvasive transthoracic application of low-frequency ultrasound (1) greatly augments the efficacy of t-PA-mediated thrombolysis, (2) seems safe, and (3) has substantial potential as a noninvasive adjunct to improve coronary patency without increasing the risk of bleeding.

Diabetes mellitus and outcome after primary coronary angioplasty for acute myocardial infarction: lessons from the GUSTO-IIb angioplasty substudy

OBJECTIVESWe sought to compare the efficacy of primary angioplasty in diabetics versus nondiabetics and to evaluate the relative benefits of angioplasty over thrombolytic therapy among diabetics.BACKGROUNDPrimary angioplasty for myocardial infarction is at least as effective as thrombolytic therapy in the general population. However, the influence of diabetic status on outcome after primary angioplasty versus thrombolysis remains unknown.METHODSPatients in the Global Use of Strategies To Open Occluded Arteries in Acute Coronary Syndromes (GUSTO-IIb) Angioplasty Substudy were randomized to receive either primary angioplasty or accelerated alteplase. The interaction of diabetic status (diabetics n = 177, nondiabetics n = 961) and treatment strategy with the occurrence of the primary end point (death, nonfatal reinfarction or nonfatal, disabling stroke at 30 days) was analyzed (power to detect a 40% relative reduction in the primary end point with alpha = 0.05 and beta = 0.20). Among patients who were randomized to and underwent primary angioplasty, procedural success (defined as residual stenosis <50% and TIMI grade 3 flow) was assessed based on diabetic status.RESULTSCompared with nondiabetics, diabetics had worse baseline clinical and angiographic profiles. Despite more severe stenosis and poorer flow in the culprit artery, procedural success with angioplasty was similar for diabetics (n = 81; 70.4%) and nondiabetics (n = 391; 72.4%). Outcome at 30 days was better for nondiabetics randomized to angioplasty versus alteplase (adjusted odds ratio, 0.62; 95% confidence interval, 0.41–0.96) with a similar trend for diabetics (0.70, [0.29–1.72]). We noted no interaction between diabetic status and treatment strategy on outcome (p = 0.88).CONCLUSIONSPrimary angioplasty was similarly successful in diabetics and nondiabetics and appeared to be more effective than thrombolytic therapy among diabetics with acute infarction.

Lanoteplase

Lanoteplase is a recombinant plasminogen activator, which when administered as a single bolus intravenous injection, displays thrombolytic activity. In the phase II InTIME trial, lanoteplase dose-dependently increased reperfusion rates at 60 and 90 minutes in patients with acute myocardial infarction and at 90 (but not 60) minutes lanoteplase 120 kU/kg was significantly superior to alteplase in restoring TIMI grade 2 and 3 flow (in 83.0 and 71.4% of patients, respectively). Preliminary results from the phase III InTIME-II study showed that lanoteplase was as effective as alteplase in decreasing 30-day mortality. At 30 days, the combined incidence of death, reinfarction, major bleeding and heart failure was lower with lanoteplase 120 kU/kg than with alteplase 100mg. From preliminary results of the large InTIME-II study, lanoteplase 120 kU/kg showed a greater incidence of intracranial haemorrhage and mild bleeding than alteplase <or=100mg, but a similar incidence of stroke. The smaller InTIME study showed a tendency for fewer adverse events with lanoteplase.

Frequency of left ventricular free-wall rupture in patients with acute myocardial infarction treated with primary angioplasty

A total of 590 patients with myocardial infarction treated with primary angioplasty were studied, to assess the incidence and related factors of free-wall rupture in patients with acute myocardial infarction when treated with primary angioplasty. The incidence of free-wall rupture was 2.2% (13 patients); this incidence was higher in patients >65 years old, women, nonsmokers, as well as in those with anterior location and an initial TIMI grade 0 flow, but it was similar in patients with a successful or unsuccessful angiographic result.

ST-segment resolution as a marker of epicardial and myocardial reperfusion after thrombolysis: Insights from the TIMI 14 and in TIME-II trials

Patients with persistent ST segment elevation after fibrinolysis are at high risk for death and congestive heart failure, even if normal epicardial flow has been restored. In the TIMI 14 trial, combination therapy with abciximab plus reduced-dose alteplase enhanced the speed and efficacy of epicardial reperfusion. We also found that combination therapy provided an additional benefit in terms of myocardial reperfusion, as evidenced by greater ST resolution on serial 12-lead electrocardiograms. Specifically, the proportion of patients with complete (≥70%) ST resolution was higher among patients receiving combination therapy than in those treated with alteplase alone (59% vs 37%; p<0.0001). Even among patients with normal (TIMI grade 3) epicardial blood flow, combination therapy was associated with a significantly greater likelihood of complete ST resolution than was fibrinolysis alone (69% vs 44%; p=0.0002). In conclusion, combination reperfusion therapy improved myocardial (microvascular) reperfusion, independent of epicardial flow, suggesting an additional mechanism by which abciximab may improve outcomes in patients with acute MI.

Angioscopic Evaluation of Thrombi in the Culprit Coronary Lesions in Patients With Acute Myocardial Infarction

The purpose of this study was to evaluate intracoronary thrombi in the culprit lesions in patients with acute myocardial infarction (AMI) by angioscopy, and to compare them with clinical and angiographic features. We angioscopically observed the culprit coronary lesions in 66 patients with AMI (55 males and 11 females, 63.9±15.4 years old) just before interventional therapy. Thrombi were observed in 42 of 66 lesions (64%), namely, red thrombi in 16, mixed thrombi in 15, white thrombi in 11. In patients with complete obstruction (TIMI grade 0 and I), red thrombi were more frequently observed than mixed or white thrombi. On the other hand, in patients with incomplete obstruction (TIMI grade II and III), white thrombi were more frequently observed than the others. Angiographically, haziness and filling defect were significantly more frequently observed in patients with red thrombi than the others (p<0.05). The distance from proximal side branch to thrombi tended to be longer in patients with red thrombi than the others. The time from onset of AMI tended to be longer in patients with white thrombi than the others. These results suggest that blood flow may be an important determinant of thrombi characterization.

Comparison of ReoPro((R)) (abciximab) versus intracoronary thrombolysis for early coronary stent thrombosis.

AIMS: This study evaluated the treatment of early coronary stent thrombosis with intracoronary urokinase or the platelet glycoprotein IIb/IIIa receptor inhibitor ReoPro (abciximab). METHODS AND RESULTS: Seventy-four patients (126 stents) were treated immediately after identification of early (0-30 days) coronary stent thrombosis. Twenty-nine patients were treated with intracoronary urokinase (UK) (UK alone in 19; UK and additional balloon angioplasty in 10) and another 45 patients were given ReoPro((R)) (abciximab) (0.25 mg/kg as a bolus alone in 26, abciximab with additional balloon angioplasty in 19) within 30 days of stent implantation. TIMI grade 3 flow was obtained in 23 patients (79%) in the UK group and in 38 (84%) in the abciximab group (nonsignificant). Three patients (10%) in the UK group and one (2%) in the abciximab group underwent repeat percutaneous transluminal coronary angioplasty (PTCA) (nonsignificant). Five patients (17%) in the UK group and three (7%) in the abciximab group were referred for urgent coronary artery bypass graft surgery (CABG) because of residual thrombus and refractory ischemia (nonsignificant). Repeat revascularization was necessary in eight patients (28%) in the UK group versus four (9%) in the abciximab group (p < 0.05). Five patients (17%) in the UK group and eight (18%) in the abciximab group developed myocardial infarction (nonsignificant). Five patients (17%) in the UK group (cardiogenic shock (three), cerebral hemorrhage (one) and pneumonia (one)) and three (6.6%) in the abciximab group (cardiogenic shock (two), heart failure (one)) died within 30 days (nonsignificant). Overall, noncardiac complications (bleeding including surgical repair of groin) were observed in 11 patients (38%) in the UK group and three (7%) in the abciximab group (p < 0.001). CONCLUSION: Compared to urokinase, abciximab reduced the need for repeat revascularization procedures and the risk of noncardiac events, including bleeding complications in patients with early coronary stent thrombosis.

Adenosine use during aortocoronary vein graft interventions reverses but does not prevent the slow-no reflow phenomenon.

Slow or no reflow (SNR) complicates 10-15% of cases of percutaneous intervention (PI) in saphenous vein bypass graft (SVG). To date there have been limited options for the prevention and treatment of this common and potentially serious complication. We evaluated the procedural outcome of 143 consecutive SVG interventions. We compared patients who received pre-intervention intra-graft adenosine boluses with those who did not. In addition we examined the efficacy of adenosine boluses to reverse slow-no reflow events. Angiograms were reviewed and flow graded (TIMI grade) by film readers blinded to the use of any intraprocedural drug or clinical history. Seventy patients received intragraft adenosine boluses before percutaneous intervention (APPI), 73 received no preintervention adenosine (NoAPPI). There were no significant angiographic differences between the two groups at baseline. A total of 20 patients experienced SNR. The incidence of SNR was similar in the two groups (APPI = 14.2% vs. NoAPPI = 13.6%, P = 0.9). SNR was treated with repeated, rapid boluses (24 microg each) of intra-graft adenosine. Reversal of SNR was observed in 10 of 11 patients (91%) who received high doses of adenosine (>/=5 boluses, mean 7.7 +/- 2.6) and in 3 of 9 (33%) of those who received low doses (<5 boluses, mean 1.5 +/- 1.2). Final TIMI flow was significantly better in the high dose than in the low dose group (final TIMI 2.7 +/- 0.6 vs. 2 +/- 0.8, P = 0.04). No significant untoward complications were observed during adenosine infusion. These findings suggest that SNR after PI in SVG is not prevented by pre-intervention adenosine, but it can be safely and effectively reversed by delivery of multiple, rapid and repeated boluses of 24 microg of intra-graft adenosine.

Research and development of novel modified tissue-type plasminogen activator (t-PA), pamiteplase

Tissue-type plasminogen activator (t-PA) is a potent thrombolytic agent that, owing to its strict fibrin specificity, is superior to urokinase and streptekinase. However, due to its extremely short half life (approximately 5 min), it is necessary to administer this drug by high-dosage infusion, increasing the possibility of systemic bleeding. We therefore considered it clinically desirable to create a thrombolytic agent with a prolonged plasma half life that can be administered by bolus injection. To this end, we created several genetically modified t-PA analogues and screened them for thrombolytic activity and in vivo pharmacokinetics. Of these, Pamiteplase (YM866) showed an improved plasma clearance profile without a reduction in fibrinolytic potency and fibrin specificity. In clinical studies on acute myocardial infarction (AMI), patients were injected with bolus Pamiteplase intravenously at dosages of 0.05, 0.1, or 0.2 mg/kg-body weight. Angiographical examination of coronary artery showed that high incidence (70-76%) of reperfusion evaluated as TIMI grade II or III was achieved by the injection of 0.1 or 0.2 mg/kg of Pamiteplase. No anti-Pamiteplase antibodies have thus far been detected in the blood of patients. From these results, we conclude that it is of great clinical significance that Pamiteplase can be administered by single bolus injection to AMI patients.

Impaired coronary blood flow in nonculprit arteries in the setting of acute myocardial infarction

OBJECTIVES AND BACKGROUNDWhile attention has focused on coronary blood flow in the culprit artery in acute myocardial infarction (MI), flow in the nonculprit artery has not been studied widely, in part because it has been assumed to be normal. We hypothesized that slower flow in culprit arteries, larger territories infarcted and hemodynamic perturbations may be associated with slow flow in nonculprit arteries.METHODSThe number of frames for dye to first reach distal landmarks (corrected TIMI [Thrombolysis in Acute Myocardial Infarction] frame count [CTFC]) were counted in 1,817 nonculprit arteries from the TIMI 4, 10A, 10B and 14 thrombolytic trials.RESULTSNonculprit artery flow was slowed to 30.9 ± 15.0 frames at 90 min after thrombolytic administration, which is 45% slower than normal flow in the absence of acute MI (21 ± 3.1, p < 0.0001). Patients with TIMI grade 3 flow in the culprit artery had faster nonculprit artery CTFCs than those patients with TIMI grades 0, 1 or 2 flow (29.1 ± 13.7, n = 1,050 vs. 33.3 ± 16.1, n = 752, p < 0.0001). The nonculprit artery CTFC improved between 60 and 90 min (3.3 ± 17.9 frames, n = 432, p = 0.0001), and improvements were related to improved culprit artery flow (p = 0.0005). Correlates of slower nonculprit artery flow included a pulsatile flow pattern (i.e., systolic flow reversal) in the nonculprit artery (p < 0.0001) and in the culprit artery (p = 0.01), a left anterior descending artery culprit artery location (p < 0.0001), a decreased systolic blood pressure (p = 0.01), a decreased ventriculographic cardiac output (p = 0.02), a decreased double product (p = 0.0002), a greater percent diameter stenosis of the nonculprit artery (p = 0.01) and a greater percent of the culprit artery bed lying distal to the stenosis (p = 0.04). Adjunctive percutaneous transluminal coronary angioplasty (PTCA) of the culprit artery restored a culprit artery CTFC (30.4 ± 22.2) that was similar to that in the nonculprit artery at 90 min (30.2 ± 13.5), but both were slower than normal CTFCs (21 ± 3.1, p < 0.0005 for both). If flow in the nonculprit artery was abnormal (CTFC ≥ 28 frames) then the CTFC after PTCA in the culprit artery was 17% slower (p = 0.01). Patients who died had slower global CTFCs (mean CTFC for the three arteries) than patients who survived (46.8 ± 21.3, n = 47 vs. 39.4 ± 16.7, n = 1,055, p = 0.02).CONCLUSIONSAcute MI slows flow globally, and slower global flow is associated with adverse outcomes. Relief of the culprit artery stenosis by PTCA restored culprit artery flow to that in the nonculprit artery, but both were 45% slower than normal flow.

Efegatran sulfate as an adjunct to streptokinase versus heparin as an adjunct to tissue plasminogen activator in patients with acute myocardial infarction

Background Previous clinical studies have shown that direct antithrombins can accelerate clot lysis after treatment with streptokinase in acute myocardial infarction (MI). Efegatran is a new direct antithrombin, which in experimental animals has been shown to enhance thrombolysis, reduce rate of reocclusion, and limit infarct size. This study was designed to compare the efficacy of efegatran plus streptokinase versus heparin plus accelerated tissue plasminogen activator (TPA) in coronary reperfusion in acute MI. Methods and Results In this randomized, dose-finding study (n = 245), we initially explored 4 doses of efegatran sulfate in combination with streptokinase (1.5 million U) given intravenously within 12 hours of symptom onset. The optimal dosage group of 0.5 mg/kg per hour was expanded and compared with heparin plus accelerated TPA. The primary end point was complete patency (Thrombolysis In Myocardial Infarction [TIMI] grade 3) at 90 minutes after thrombolytic therapy, assessed in a core angiographic laboratory. Infarct-related vessel patency (TIMI grade 2 or 3) and complete patency (TIMI grade 3) were 73% and 40% in the efegatran/streptokinase group versus 79% and 53% in the heparin/TPA group ( P = not significant). In-hospital mortality rate was 5% for the efegatran/streptokinase group versus 0% for the heparin/TPA group ( P = not significant). Major bleeding occurred in 23% of patients in the efegatran/streptokinase group versus 11% in the heparin/TPA group ( P = not significant). No intracranial hemorrhage occurred. Conclusions The combination of efegatran plus streptokinase is not superior to the current therapy of heparin and accelerated TPA in achieving early patency. In addition, there is no indication that this experimental treatment can achieve better clinical outcome. (Am Heart J 1999;138:696-704.)

Clinical experience with a spiral balloon centering catheter for the delivery of intracoronary radiation therapy

Purpose. To develop and evaluate an intravascular radiation delivery catheter that incorporates a centering mechanism and that allows side branch and distal artery perfusion. Methods and Materials. The Galileo™ Centering Catheter (Guidant Vascular Interventions, Houston, TX) incorporates a rapid exchange tip design. A unique spiral balloon allows centering and facilitates perfusion to the distal artery and side branches. The catheter contains a dedicated dead-end lumen for source wire delivery to the lesion site. The treatment area is precisely defined by radiopaque markers. Results. In three clinical trials to date, radiation (or placebo) was delivered successfully to 300 of 312 patients (96%). With balloon inflation, TIMI grade 2 or 3 flow was achieved in side branches in 82% and in the distal artery in 77% of patients. Despite treatment (dwell) times ranging from 87 to 948 s (mean = 250 s), only 8% of patients required fractionation of treatment. Conclusion. The Galileo™ Centering Catheter is a safe and highly effective method for delivering intracoronary radiation therapy. Its unique design provides centering of the source while allowing side branch and distal coronary perfusion during treatment. This catheter would facilitate intracoronary radiation therapy and allow uniform and reproducible dose delivery to the target in the artery wall.

Low molecular weight heparin (dalteparin) as adjuvant treatment to thrombolysis in acute myocardial infarction—a pilot study: Biochemical Markers in Acute Coronary Syndromes (BIOMACS II)

OBJECTIVESThis randomized, double blind, placebo-controlled pilot trial evaluated the effect of dalteparin as an adjuvant to thrombolysis in patients with acute myocardial infarction regarding early reperfusion, recurrent ischemia and patency at 24 h.BACKGROUNDLow-molecular-weight heparin, given subcutaneously twice daily without monitoring, might be an attractive alternative to conventional intravenous heparin in the treatment of acute myocardial infarction.METHODSIn 101 patients dalteparin/placebo 100 IU/kg was given just before streptokinase and a second injection 120 IU/kg after 12 h. Monitoring with continuous vector-ECG was done to obtain signs of early reperfusion and later ischemic episodes. Blood samples for myoglobin were obtained at start and after 90 min to evaluate signs of reperfusion. Coronary angiography was performed after 20–28 h to evaluate TIMI-flow in the infarct-related artery.RESULTSDalteparin added to streptokinase tended to provide a higher rate of TIMI grade 3 flow in infarct-related artery compared to placebo, 68% versus 51% (p = 0.10). Dalteparin had no effects on noninvasive signs of early reperfusion. In patients with signs of early reperfusion, there seemed to be a higher rate of TIMI grade 3 flow, 74% versus 46% (myoglobin) (p = 0.04) and 73% versus 52% (vector-ECG) (p = 0.11). Ischemic episodes 6–24 h. after start of treatment were fewer in the dalteparin group, 16% versus 38% (p = 0.04).CONCLUSIONSWhen dalteparin was added as an adjuvant to streptokinase and aspirin, there were tendencies for less ECG monitoring evidence of recurrent ischemia and better patency at 24 h, warranting further study.

Primary stenting in acute myocardial infarction: a 30-day follow up study.

Primary coronary stenting is being increasingly used in patients undergoing primary coronary angioplasty for acute myocardial infarction. In this prospective study we evaluated our experience of direct angioplasty in 68 patients with acute myocardial infarction of whom 57 received intracoronary stents using high-pressure deployment (> or =12 atmospheres) with adjunct aspirin and ticlopidine therapy without coumadin. All patients underwent pre-discharge follow-up angiography. Stent implantation was successful in all patients. Stent thrombosis was not seen in any patient. However, TIMI grade 3 flow was obtained in only 51 patients (89.6%) with evidence of slow flow present in remaining six patients. Follow-up angiograms showed no stent thrombosis but five out of the six patients (83%) with slow-flow phenomenon persisted to have slow flow. These patients had lower left ventricular ejection fraction as compared to patients with TIMI 3 flow at follow-up angiography (27.5 +/- 10.2% vs. 42.1 +/- 15.2%, P < .001) and a high mortality (two out of six) within 30 days. Primary stenting is safe and feasible in the majority of patients with good short-term outcomes, but persistent slow-flow phenomenon with adverse clinical outcome is seen in a small but significant number of patients.

Ultrasound Thrombolysis: An Alternative to the Pharmacological Approach

The clinical management of intracoronary thrombosis presents a therapeutic challenge. A variety of pharmaceutical agents have been investigated as an adjunct to balloon angioplasty and stenting with no conclusive evidence to which is the best therapeutic strategy. Our group has investigated the use of therapeutic ultrasound in interventional cardiology over the last few years. Ultrasonic energy (41 KHz) is transmitted from a transducer as longitudinal vibrations of a 140‐cm long solid probe, which directs the energy into the arterial system. In the ACUTE study, consecutive patients with first infarct, only acute anterior myocardial infarction, and occluded LAD were studied. Final flow of TIMI grade 3 was achieved in 93% of the patients. During the procedure, there were no clinical or angiographic adverse events. At 6‐month follow‐up, a significant improvement of left ventricular ejection fraction was observed. There was a low clinical event rate. The Acolysis Registry followed the ACUTE trial. The purpose of this registry was to investigate coronary ultrasound thrombolysis in the different clinical settings of intracoronary thrombosis. Preliminary data (n = 51), show that 56% of the patients were treated for acute myocardial infarction, 25% for unstable angina, and 19% for diseased saphenous vein grafts (SVG). Ninety percent of the vessels were occluded (TIMI 0‐1 flow) at baseline, median age clot was 4 days. Device and procedural success was obtained in 84% and 82%, respectively. Intriguing data came from the SVG subset of patients. Angiographic analysis revealed that 75% of the SVGs were occluded prior to the procedure. Sonication led to successful recanalization in 70% of the patients. In summary, this data suggests that therapeutic ultrasound is effective and safe for inducing intracoronary thrombolysis. Ultrasound can be used to treat thrombi that are a few hours to a few weeks old. Lysis of intracoronary thrombus by ultrasound is a safe and effective procedure. Furthermore, ultrasound thrombolysis is a viable alternative to the pharmacological approach. Local application of ultrasound achieves a high success rate with minimal local or systemic adverse events.

Influence of treatment delay on infarct size and clinical outcome in patients with acute myocardial infarction treated with primary angioplasty.

The purpose of this analysis was to determine the influence of an additional treatment delay inherent in transfer to an angioplasty center for primary angioplasty of patients with acute myocardial infarction who are first admitted to hospitals without angioplasty facilities. Several randomized trials have demonstrated the benefits of primary angioplasty in acute myocardial infarction. In recent years, increasing numbers of patients with myocardial infarction, initially admitted to hospitals without angioplasty facilities are transported to our hospital for primary angioplasty. However, the additional delay due to the transport may have a deleterious effect on infarct size and clinical outcome. In a three-year period (December 1993 to November 1996), 207 consecutive patients who were transferred for primary angioplasty were analyzed in a matched comparison with non-transferred patients. Matching criteria were age, sex, infarct location, presentation delay and Killip class. Patients who were transferred had an additional median delay of 43 min. This resulted in a more extensive enzymatic infarct size and a lower ejection fraction measured at 6 months. The rate of angioplasty success defined as TIMI grade 3 flow, and the 6-month mortality rate (7%) were comparable in both groups. The additional delay had a deleterious effect on myocardial salvage, reflected by a larger infarct size and a lower left ventricular function. However, the patency rate and 6-month clinical outcome were not affected by this delay.

Coronary flow reserve may predict myocardial recovery after myocardial infarction in patients with TIMI grade 3 flow

Background The aim of the study was to determine whether the recovery of global and regional left ventricular function after successful percutaneous transluminal angioplasty (PTCA) could be predicted by measuring coronary flow reserve before performing the intervention.Methods and Results Thirty-two patients underwent PTCA 6.9 ± 3.4 days after a recent myocardial infarction. Coronary flow reserve was determined in the infarct-related artery before PTCA by using an intracoronary Doppler tipped wire. Global and regional wall motion were determined by 2-dimensional echocardiography before the Flowire study and again 7 weeks after the angioplasty. Whereas the global and regional wall motion score indices improved in 20 patients (recovery group), they deteriorated or did not change in 9 patients (nonrecovery group). Coronary flow reserve distal to the lesion in the infarct-related artery was significantly higher in the recovery group (1.43 ± 0.57 vs 0.98 ± 0.70, P =.0001). Coronary flow reserve distal to the lesion in the infarct-related artery was <1.1 in patients whose global or regional left ventricular function did not improve at follow-up, whereas flow reserve ranged between 1.1. and 1.8 while patients in whom left ventricular function improved.Conclusions These results suggest that the absence of inducible coronary flow reserve may predict failure of left ventricular systolic function to improve between the first and sixth week after infarction. Measurement of flow reserve with a Flowire at the time of diagnostic angiography after recent myocardial infarction may ultimately prove helpful in deciding whether to proceed with revascularization. (Am Heart J 1998;136:335-44.)

Do 90-minute TIMI grade flows predict mortality in acute MI?

Do 90-minute TIMI grade flows predict mortality in acute MI?