Fast-track thrombolysis protocol for acute limb ischemia.

OBJECTIVE: Catheter-directed thrombolysis in the treatment of acute lower extremity arterial occlusions often requires several interventional sessions to generate successful outcomes. It is typically an expensive procedure, necessitating extended hospital length of stay (LOS) that may be associated with an increase in both local and systemic hemorrhagic complications. Five years ago, we created the fast-track thrombolysis protocol for arteries (FTTP-A) to deal with these concerns. The goal of our protocol is to re-establish patency during the first session of thrombolysis, thus decreasing costs and complications associated with prolonged periods of thrombolytic exposure. METHODS: A retrospective study of 42 patients who were treated for acute limb ischemia at our institution by FTTP-A from January 2014 to February 2019 was performed. FTTP-A includes periadventitial lidocaine injection at the arterial puncture site under ultrasound guidance, contrast arteriography of the entire targeted segment, pharmacomechanical rheolytic thrombectomy of the occluded arterial segment, tissue plasminogen activator infusion along the occluded segment, balloon maceration of the thrombus, and (if deemed necessary) placement of a stent in an area of significant (≥30%) stenosis that is refractory to balloon angioplasty and thrombolysis. After the stenosis or thrombus is cleared, patients are prescribed an oral anticoagulant agent. RESULTS: Primary FTTP-A (50 total interventions) was performed in 42 patients. The median age of patients was 67.2 ± 12.2 years (range, 41-98 years), and 54.8% were male; 59.5% of the procedures were performed on the left lower extremity. Initial arterial access was obtained through the common femoral artery in 39 of 42 cases (92.9%); in the remaining 3 cases, it was obtained in a left bypass access site, a right femoral-popliteal graft, and a right femoral-femoral graft. The mean operative time was 148.9 ± 62.9 minutes (range, 83-313 minutes), and the mean volume of tissue plasminogen activator infused was 9.7 ± 4.0 mg (range, 2-20 mg). The median cost including medications and interventional tools was $4673.19 per procedure. The mean postoperative LOS was 3.1 ± 4.5 days (range, 1-25 days). Median postoperative LOS was 1 day. Mean postoperative follow-up was 27 ± 19.2 months (range, 0-62 months). Single-session FTTP-A was successful in 81% (n = 34/42) of patients; the remaining 8 patients (19%) required a single additional session. Of the 42 patients, 34 (81%) required arterial stenting. Periprocedural complications consisted of one patient with hematuria, which resolved, and one patient with thrombocytopenia, which resolved. No patients experienced rethrombosis within 30 days of FTTP-A. During the 5-year study period, there was no significant local or systemic hemorrhage, limb loss, or mortality related to this protocol. CONCLUSIONS: FTTP-A appears to be a safe, efficacious, and cost-effective procedure in the resolution of acute lower extremity arterial occlusions.

Single- versus multiple-stage catheter-directed thrombolysis for acute iliofemoral deep venous thrombosis does not have an impact on iliac vein stent length or patency rates.

BACKGROUND: Incomplete venous thrombolysis and residual nonstented iliac vein disease are known predictors of recurrent deep venous thrombosis (DVT). Controversy exists as to whether the number of thrombolysis sessions affects total stent treatment length or stent patency. The goal of this study was to evaluate the outcomes of patients who underwent single vs multiple catheter-directed lysis sessions with regard to stent extent and patency. METHODS: Consecutive patients who underwent thrombolysis and stenting for acute iliofemoral DVT between 2007 and 2018 were identified and divided into two groups on the basis of the number of treatments performed (one vs multiple sessions). Operative notes and venograms were reviewed to determine the number of lytic sessions performed and stent information, including size, location, total number, and length treated. End points included total stent length, 30-day and long-term patency, and post-thrombotic syndrome (Villalta score ≥5). The χ2 comparisons, logistic regression, and survival analysis were used to determine outcomes. RESULTS: There were 79 patients who underwent lysis and stenting (6 bilateral interventions; mean age, 45.9 ± 17 years; 48 female). Ten patients (12 limbs) underwent single-stage treatment with pharmacomechanical thrombolysis, and the remaining 69 (73 limbs) had two to four operating room sessions combining pharmacomechanical and catheter-directed thrombolysis. Patients who underwent a single-stage procedure were older and more likely to have a malignant disease. These patients received less tissue plasminogen activator compared with the multiple-stage group (17.2 ± 2.2 mg vs 27.6 ± 11.6 mg; P = .008). Average stent length was 8.8 ± 5.2 cm for the single-stage group vs 9.2 ± 4.6 cm for the multiple-stage group (P = .764). Patients who underwent a single-stage procedure had no difference in average length of stay from that of patients who underwent multiple sessions (8.5 days vs 5.9 days; P = .269). The overall 30-day rethrombosis rate was 7.3%. Two-year patency was 72.2% and 74.7% for the single and multiple stages, respectively (P = .909). The major predictors for loss of primary patency were previous DVT (hazard ratio [HR], 5.99; P = .020) and incomplete lysis (HR, 5.39; P = .014) but not number of procedures (HR, 0.957; P = .966). The overall post-thrombotic syndrome rate was 28.4% at 5 years and was also not associated with the number of treatment sessions. CONCLUSIONS: Single- vs multiple-stage thrombolysis for DVT is not associated with a difference in extent of stent coverage. Patency rates remain high for iliac stenting irrespective of the number of lytic sessions, provided lysis is complete and the diseased segments are appropriately stented.

Fast-track thrombolysis protocol: A single-session approach for acute iliofemoral deep venous thrombosis.

OBJECTIVE: Catheter-directed thrombolysis in the treatment of acute iliofemoral deep venous thrombosis (IFDVT) often requires more than one interventional session to yield successful outcomes. Catheter-directed thrombolysis is generally expensive, requiring prolonged hospital stay that may be associated with increased local and systemic hemorrhagic complications. We developed the fast-track thrombolysis protocol (FTTP) to address these issues. The goal of FTTP is to restore patency during the initial session of thrombolysis, thereby minimizing costs and complications associated with prolonged thrombolysis. METHODS: A retrospective analysis of 38 patients treated for acute IFDVT using FTTP at our institution from January 2014 to February 2019 was performed. The protocol includes periadventitial injection of lidocaine at the venipuncture site under ultrasound guidance, contrast venography of the entire target segment, pharmacomechanical rheolytic thrombectomy of the occluded venous segment, tissue plasminogen activator infusion along the occluded segment, balloon maceration of the thrombus, and, if indicated, venous stent placement in areas of significant (≥50%) stenosis refractory to thrombolysis and balloon angioplasty. Once the thrombus was cleared, patients were prescribed oral antithrombotic therapy. RESULTS: Thirty-eight primary FTTPs (45 total interventions) were performed in 38 patients. The median age was 66 years (range, 39-93 years); 60.5% were female. Initial venous access was most often obtained through the popliteal vein, followed by the femoral and great saphenous veins. The mean operative time was 122 minutes (range, 59-249 minutes), and the median volume of tissue plasminogen activator infused was 10 mg (range, 4-20 mg). The median cost per procedure, including devices and medication, was $5374.45. Median postoperative length of stay was 1 day (range, 1-45 days). Successful single-session FTTP, as determined by completion venography, was accomplished in 81.5% (n = 31/38) of cases. The remaining seven cases (18.5%) required one additional session. Of the 38 patients, 30 (79%) required iliac vein stenting. Periprocedural complications consisted of one patient with retroperitoneal hemorrhage that was managed conservatively. No patients experienced rethrombosis within 30 days of FTTP. During the 5-year study period, there were no cases of pulmonary embolism, significant local or systemic hemorrhage, limb loss, or mortality. CONCLUSIONS: FTTP, as presented herein, appears to be a safe, effective, and cost-effective technique in the resolution of acute IFDVT.

MRI assessment of uterine artery patency and fibroid infarction rates 6 months after uterine artery embolization with nonspherical polyvinyl alcohol.

PURPOSE: We have observed significant rates of uterine artery patency after uterine artery embolization (UAE) with nonspherical polyvinyl alcohol (nsPVA) on 6 month follow-up MR scanning. The study aim was to quantitatively assess uterine artery patency after UAE with nsPVA and to assess the effect of continued uterine artery patency on outcomes. METHODS: A single centre, retrospective study of 50 patients undergoing bilateral UAE for uterine leiomyomata was undertaken. Pelvic MRI was performed before and 6 months after UAE. All embolizations were performed with nsPVA. Outcome measures included uterine artery patency, uterine and dominant fibroid volume, dominant fibroid percentage infarction, presence of ovarian arterial collaterals, and symptom scores assessed by the Uterine Fibroid Symptom and Quality of Life questionnaire (UFS-QOL). RESULTS: Magnetic resonance angiographic evidence of uterine artery recanalization was demonstrated in 90 % of the patients (64 % bilateral, 26 % unilateral) at 6 months. Eighty percent of all dominant fibroids demonstrated >90 % infarction. The mean percentage reduction in dominant fibroid volume was 35 %. No significant difference was identified between nonpatent, unilateral, and bilateral recanalization of the uterine arteries with regard to percentage dominant fibroid infarction or dominant fibroid volume reduction. The presence of bilaterally or unilaterally patent uterine arteries was not associated with inferior clinical outcomes (symptom score or UFS-QOL scores) at 6 months. CONCLUSION: The high rates of uterine artery patency challenge the current paradigm that nsPVA is a permanent embolic agent and that permanent uterine artery occlusion is necessary to optimally treat uterine fibroids. Despite high rates of uterine artery recanalization in this cohort, satisfactory fibroid infarction rates and UFS-QOL scores were achieved.

Assessment of long-term vasoplegia induced by brachial plexus block: a favorable effect for hemodialysis angioaccess surgery?

PURPOSE: Loco-regional anesthesia, along with the neurosensitive inhibition causes arterial and venous vasodilatation, that could be of interest for vascular access surgery. We evaluated the long term vasoplegia persistence after brachial plexic block. METHODS: Five patients submitted to brachial plexus block for an orthopedic procedure have been observed. Both radial arteries, that of the blocked arm and the opposite as a control, were analyzed by ultrasound examination, at time 0 and 360 minutes after anesthesia induction. All patients were treated with the same anesthesiologic protocol: axillary approach, use of an electroneurostimulator, injection 10 ml of ropivacain 7.5% + 10 ml of mepivacain 2%. The parameters evaluated from the arterial ultrasound flowmetry were: peak systolic velocity (PSV), end diastolic velocity (EDV) and resistance index (RI). RESULTS: No modification of the arterial flow were observed in the control arm at 0 and 360'after block induction. The blocked arm instead showed a significant decrease of the resistive index, stable at 360 minutes. CONCLUSIONS: The vasoplegia accompaning plexic block lasted 6 hours after anesthesia induction. Whereas this longstanding haemodynamic effect is beneficial for early patency of vascular access for hemodialysis, needs to be ascertained by further investigations.

Plasma N-terminal fragment of the prohormone B-type natriuretic peptide concentrations in relation to time to treatment and Thrombolysis in Myocardial Infarction (TIMI) flow: a substudy of the Assessment of the Safety and Efficacy of a New Treatment Strategy with Percutaneous Coronary Intervention (ASSENT IV-PCI) trial.

BACKGROUND: We investigated the prognostic significance of plasma N-terminal fragment of the prohormone B-type natriuretic peptide (Nt-proBNP) concentrations in addition to time to reperfusion and Thrombolysis in Myocardial Infarction (TIMI) flow before and after coronary intervention in patients with ST elevation myocardial infarction (STEMI) from the database of the Assessment of the Safety and Efficacy of a New Treatment Strategy with Percutaneous Coronary Intervention (ASSENT IV-PCI) trial. METHODS: Plasma Nt-proBNP was available in 1,037 patients with STEMI. Patients were randomized either to primary (p-PCI) or to full-dose tenecteplase before PCI (f-PCI).The study end point was the composite of death, cardiogenic shock, or congestive heart failure at 90 days. RESULTS: According to classification tree analysis, patients with Nt-proBNP levels >694 pg/mL had the highest primary end point rates (33.8% vs 11%, P < .001). In Cox regression analysis, Nt-proBNP >694 pg/mL strongly predicted 90-day survival even among patients with short treatment delay (f-PCI < or =3 hours: hazard ratio [HR] 2.63, P = .002 and p-PCI < or =3 hours: HR 4.87, P < .001, respectively). Patients with TIMI 3 flow after coronary intervention were at significantly higher risk of the primary end point if admission Nt-proBNP exceeded 694 pg/mL (f-PCI: HR 2.88, P < .001 and p-PCI: HR 3.84, P < .001, respectively). In multivariable analysis, Nt-proBNP >694 pg/mL significantly (P = .001) predicted 90-day survival in addition to age (P < .001), TIMI flow after PCI (P < .001), body mass index (P = .026), anterior wall infarction (P = .035), and systolic blood pressure at randomization (P = .036), respectively. CONCLUSION: Elevated plasma concentrations of Nt-proBNP in the early phase of STEMI determine in-hospital and 90-day outcome after infarction irrespective of time to treatment and pre- or postinterventional TIMI flow.

Noninvasive assessment of left and right internal mammary artery graft patency using transthoracic color Doppler echocardiography.

BACKGROUND: The aim of this study was to evaluate the patency of left and right internal mammary artery grafts respectively on the left anterior descending and right coronary artery by noninvasive transthoracic color Doppler echocardiography. METHODS: Thirty eight patients (34 males, 4 females, mean age 59 +/- 2 years), with a history of coronary artery bypass grafting for a total of 42 mammary artery grafts, were studied by means of color Doppler echocardiography at baseline and after vasodilation with dipyridamole infusion (0.56 mg/kg i.v. over 4 min). The evaluated echocardiographic parameters included: systolic (SPV) and diastolic peak velocities (DPV), systolic (SVI) and diastolic velocity-time integrals (DVI), and the DPV/SPV and DVI/SVI ratios. We also calculated the dipyridamole infusion to baseline ratio of the diastolic peak velocities (DPVdip/DPVbaseline), the index of internal mammary artery graft blood flow reserve and the percent DPV increment as an index of graft stenosis. RESULTS: On the basis of coronary angiography, two groups were selected: group A (36 mammary grafts) with patent grafts and group B (6 mammary grafts) with moderate or severe stenosis of the grafts. Group A had a predominant diastolic pattern with a DPV of 0.24 +/- 0.13 m/s, whereas group B had a predominant systolic pattern with a reduced DPV of 0.12 +/- 0.03 m/s (p < 0.01). Dipyridamole induced an increase in the DPV respectively of 86.8 +/- 64.4% in group A and 13.8 +/- 15.9% in group B (p < 0.001). Statistical analysis (Mann-Whitney test) revealed a significant difference between the two groups for the baseline DPV (p < 0.01), DVI (p < 0.05), DPV/SPV ratio (p < 0.005), DVI/SVI ratio (p < 0.05), and for the after dipyridamole infusion values: DPV (p < 0.0001), DVI (p < 0.005), DPV/SPV ratio (p < 0.001), and DVI/SVI ratio (p < 0.05). Multivariate analysis showed that the percent DPV increment, the DPVdip/DPVbaseline ratio and the baseline DPV were independent determinants of the stenosis as evaluated at angiography (beta = -0.38, p < 0.01; beta = -0.37, p < 0.01, and beta = -0.33, p < 0.05, respectively; cumulative r2 = 0.25, standard error 0.30 m/s, p < 0.005). CONCLUSIONS: The echocardiographic evaluation of the mammary grafts is a simple, noninvasive method for the assessment of the graft patency and of the functional status of the vessel. The percent DPV increment and baseline DPV were independent determinants of mammary graft stenosis.

Contemporary treatment of thrombosed hemodialysis grafts.

Maintaining hemodialysis grafts remains a difficult problem. Before the early 1990s, graft declotting was usually performed in the surgical suite. Percutaneous declotting has been evolving since the mid-1980s. Initially, a low-dose thrombolytic infusion of streptokinase through a single catheter was used. Crossing catheters with a higher-dose infusion of urokinase was then introduced. This technique was modified with the adjunctive use of pharmacomechanical techniques with the use of compliant balloons and the adjunctive use of heparin. The advent of the "lyse-and-wait" technique provided a simpler and quicker way to declot thrombosed grafts by using urokinase, with similar outcomes. Since the removal of urokinase from the market, multiple mechanical devices have been used with similar success. Recent reports concerning the use of newer-generation thrombolytic agents report similar outcomes, with a reduction in total cost.

DIAS I: duplex-sonographic assessment of the cerebrovascular status in acute stroke. A useful tool for future stroke trials.

BACKGROUND AND PURPOSE: A number of controlled trials have evaluated the benefit of intravenous thrombolysis in acute stroke with inconsistent results. None of these studies assessed the initial vascular status or provided information regarding the recanalization rate after therapy. Further trials need to clarify whether certain subgroups might possibly benefit more than others from intravenous thrombolysis. Therefore, a fast and valid method for assessment of cerebrovascular status is needed. In this multicenter study, we evaluated the potentials and limitations of color-coded duplex sonography (TCCS) for cerebrovascular status assessment in acute stroke patients before and after therapy. Furthermore, we compared the recanalization rate for patients referred to thrombolytic and conservative medical therapy. METHODS: Fifty-eight patients suffering from hemispheric stroke were enrolled consecutively in 8 centers. Duplex sonography was performed on admission, 2 hours after start of therapy, and 24 hours after onset of symptoms. Therapy was started within 6 hours. RESULTS: Intravenous thrombolysis was performed in 18 patients, conservative medical therapy in 39 patients, and early thromboendarterectomy in 1 patient. The middle cerebral artery (MCA) mainstem was patent in 29 patients (53.7%), occluded in 25 (46.3%), and was not assessable in 4 patients. Recanalization of the occluded MCA after 2 and 24 hours was diagnosed in 50% and 78% of the patients treated with rtPA and in 0% and 8% in the conservatively treated patients. CONCLUSIONS: Intravenous thrombolysis is highly effective in restoring blood flow after MCA occlusion. TCCS is suitable for assessment of the cerebrovascular status in acute stroke and therefore might define therapeutically relevant subgroups of patients in future stroke trials on the basis of their vascular pathology.

Comparison of continuous ST-segment recovery analysis with methods using static electrocardiograms for noninvasive patency assessment during acute myocardial infarction. Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) 7 Study Group.

Continuous ST-segment recovery analysis and 5 static methods using ST-segment comparison between a pre- and post-treatment electrocardiogram were compared for their ability to predict infarct-related artery patency in 82 patients with acute myocardial infarction who underwent angiography a median of 124 minutes after onset of thrombolytic treatment. Accuracy at the moment of angiography was 85% (95% confidence interval [CI] 77% to 93%) for the continuous method, and 68% (CI 57% to 78%), 78% (CI 69% to 87%), 83% (CI 74% to 91%), 82% (CI 73% to 90%), and 80% (CI 71% to 89%) for the static methods. At the moment of angiography the most accurate static method and the continuous method agreed in patency assessment in 90% of the patients (CI 84% to 97%). Agreement was reduced to 83% (CI 75% to 91%) of patients when a patency assessment was performed earlier at 90 minutes after treatment onset, and was only 77% (CI 68% to 86%), at 60 minutes. Early disagreement was mainly seen when the continuous ST recording showed ST recovery from a delayed peak ST elevation after the pretreatment static electrocardiogram or when dynamic ST changes suggesting cyclic reperfusion occurred. Continuous ST-segment recovery analysis appears to be as accurate as the most accurate static methods. Continuously updated reference points appear to give important additional information when ST recovery follows a delayed peak ST elevation or when re-elevation occurs, suggesting cyclic flow changes. Such findings appear to affect about half of patients with acute myocardial infarction treated with intravenous thrombolysis, particularly early after administration of therapy.

Cost effectiveness of thrombolytic treatment for myocardial infarction: comparison of anistreplase, alteplase and streptokinase in 270 patients treated within 4 hours.

Two hundred and seventy patients, under 71 years of age and suffering from a less than 4 h infarction diagnosed according to clinical and electrocardiographic criteria, were included: two 90-patient groups were randomized and then treated with either anistreplase (30 mg iv over 5 min) or alteplase (10 mg bolus injection + 5000 IU heparin bolus injection, followed by 90 mg alteplase over 3 h), and compared with a consecutive control series of 90 patients treated with streptokinase (1.5 million U over 1 h). Intravenous heparin and aspirin (250 mg day-1) were then prescribed routinely. The three groups were comparable as regards age (55.2 +/- 10 years), male/female ratio (10.4), the site of the infarction (42% anterior, 55% inferior) and initial clinical seriousness (Killip I = 90%, II = 8%, III = 2%). The patients were thrombolysed in 17 community hospitals, and then referred to a university hospital with catheterization facilities. An efficacy score was determined, based on four parameters: two obtained from coronary angiography and left ventriculography performed on day 6 +/- 2 (N = 252) (asynergic score and patency of the infarct-related artery), one from Tl-tomography performed at rest (infarct size) and one from radionuclide angiography (global left ventricular ejection fraction) performed between day 15 and day 21 (N = 242). The score (range: 0-24 per patient) was 17.8 +/- 6.4 for alteplase, 17.7 +/- 6.0 for anistreplase and 18.1 +/- 6.0 for streptokinase respectively (NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Considerations affecting selection of thrombolytic agents.

The data reviewed above show that the ideal thrombolytic or thrombolytic plus anticoagulant regimen does not exist. Nor is it clear to me that one regimen is unequivocally better than another in regards to clinical outcome. Publication of the full results of the ISIS-3 study and completion of the TAPS study, the GUSTO study, the TIMI-4 study plus others only now in the planning phases, should help. This review will not stay current very long. These data do, however, give some guides to certain circumstances in which one regimen might be preferred over others. If economics is a compelling issue, as it may be in public hospitals on a fixed budget or in the developing world, streptokinase may be the best choice. For early application of thrombolytic therapy, such as at the site of infarct occurrence and in automotive and aerial ambulances, anistreplase may be preferred because of its ease of administration. Previous administration of streptokinase or anistreplase (within the period of 48 h to 6 months after prior use) militate against their use as does a recent streptococcal infection. Heightened concerns about bleeding risk, except intracranially, in the absence of absolute contraindication of fibrinolytic therapy, e.g. remote gastrointestinal hemorrhage or the expected imminent need for an invasive procedure, may lead to preference for alteplase over streptokinase or anistreplase. On the other hand, heightened concerns about intracranial hemorrhage may lead to preference for streptokinase over alteplase or anistreplase. Alteplase may be preferred over non-fibrin-selective agents in the treatment of patients when administration is begun more than three hours after the presumed onset of infarction. These considerations notwithstanding, it is crucial that debates over the best choice of a regimen must not be allowed to prolong the time before administration of an effective thrombolytic agent to a patient with evolving Q-wave infarction who is a good candidate for this therapy. This review may also become dated in the not-too-distant future because of expected further advances in thrombolytic regimen. Application of new antithrombotic regimens was noted above. Future thrombolytic and antithrombotic regimens may be "cocktails" of one or more thrombolytic agents plus more powerful antithrombotic and antiplatelet agents. New generations of thrombolytic agents may replace the current first and second generation agents now used. Combination thrombolytic and anti-fibrin antibody agents and mutant tissue-type plasminogen activators with lower affinity for plasminogen activator inhibitor and longer half-lives are being developed.(ABSTRACT TRUNCATED AT 400 WORDS)

Angiographic assessment of patency and reocclusion: preliminary results of the Dutch APSAC Reocclusion Multicenter Study (ARMS).

The main objective of the ARMS (APSAC Reocclusion Multicenter Study) trial was to obtain patency and reocclusion data. In an open multicenter study, a total of 156 patients were treated with 30 U of anistreplase or anisoylated plasminogen streptokinase activator complex (APSAC) within 4 h after onset of pain. Patency of the infarct-related vessel was assessed by coronary angiography performed 90 minutes after anistreplase administration. In those patients with a patent infarct-related vessel at 90 min, repeat coronary angiography was performed at 24 h to assess the reocclusion rate. Two independent cardiologists evaluated the angiograms and scored the coronary artery perfusion of the infarct-related vessel. The preliminary data of the first 148 patients indicate that the patency rate at 90 min was 73-75% and the reocclusion rate at 24 h was 4%. This patency rate corresponds with previous studies. The low reocclusion rate is noteworthy and probably reflects the prolonged action of anistreplase.

Radionuclide imaging of myocardial perfusion and viability in assessment of acute myocardial infarction.

Technical advances in radionuclide imaging have important implications for the management of patients with acute myocardial infarction. Single-photon emission computerized tomography with thallium 201 (TI-201) offers greater accuracy than planar imaging in detecting, localizing and sizing myocardial perfusion defects. Use of single-photon emission computerized tomography with TI-201 should allow for a more accurate assessment of prognosis after myocardial infarction. A new radiopharmaceutical, technetium 99-m methoxyisobutyl isonitrile, provides a number of advantages over TI-201, including higher quality images, lack of redistribution, and the ability to assess first-pass ventricular function. Applications of TI-201 and technetium 99-m methoxyisobutyl isonitrile include assessment of arterial patency and myocardial salvage immediately after thrombolytic therapy, detection of resting ischemia after thrombolytic therapy, targeting of subsets of patients for further intervention, and predischarge assessment to predict the future course of patients after an acute myocardial infarction.