NORwegian study on DIstrict treatment of ST-Elevation Myocardial Infarction - NORDISTEMI

Description:

The goal of the trial was to evaluate immediate transfer for percutaneous coronary intervention (PCI) compared with conservative, ischemia-guided treatment among patients with ST-elevation myocardial infarction (STEMI) treated with thrombolysis with very long transfer times to PCI hospitals.

Hypothesis:

Patients treated with thrombolytic therapy for STEMI with a very long transfer time to a PCI hospital would have a reduction in major adverse cardiac events (MACE) with immediate transfer for angiography and PCI, as compared to ischemia-guided treatment in local hospitals with transfer for rescue PCI, if needed.

Study Design

  • Randomized

Patients Screened: 526
Patients Enrolled: 266
Mean Follow Up: 12 months
Mean Patient Age: 60 years
Female: 24

Patient Populations:

Age 18-75 years, symptoms of MI for <6 hours, ST-segment elevation ≥1 mm in two contiguous extremity leads or ≥2 mm in two contiguous precordial leads or new LBBB, expected time delay from first medical contact to PCI >90 minutes, receiving thrombolytic treatment with tenecteplase

Exclusions:

Standard contraindication for thrombolytic treatment, known serious renal failure (creatinine >250 mmol/L), cardiogenic shock, diseases with life expectancy <12 months

Primary Endpoints:

Composite of death, reinfarction, stroke, or new ischemia by 12 months

Secondary Endpoints:

Composite of death, reinfarction, or stroke by 12 months; bleeding complications within 30 days; transport complications; infarct size at 3 months (SPECT); quality of life at 12 months; total costs over 12 months

Drug/Procedures Used:

Patients were treated with optimal medical therapy (tenecteplase [TNK], aspirin, enoxaparin, and clopidogrel) and were then randomized to immediate transfer for angiography/PCI (n = 134) or ischemia-guided treatment in local hospitals with transfer for rescue PCI if needed (n = 132). SPECT was performed at 3 months of follow-up.

Concomitant Medications:

Aspirin (300 mg), TNK, enoxaparin (30 mg IV 1 mg/kg subcutaneously), clopidogrel (300 mg)

Principal Findings:

Median time from symptom onset to TNK administration was 117 minutes in the invasive group and 126 minutes in the conservative group (p = 0.72). There was a slight excess of patients with treated hypertension in the conservative group (38% vs. 25%, p = 0.03), but other baseline characteristics were well balanced between treatment groups. Infarct location was anterior in 41% of patients.

Angiography was performed in 99% of the invasive group and 95% of the conservative group, with median time from TNK administration to arrival in the catheterization laboratory of 130 minutes and 5.5 days, respectively. PCI was performed in 89% of the invasive group and 71% of the conservative group, with a median time from TNK to PCI of 163 minutes and 3.0 days, respectively. The median transfer distance to the PCI center was 158 km among invasive patients. There were few complications associated with the transport: one death in the invasive group, ventricular fibrillation in 3% of the invasive group, and ventricular tachycardia in 1.5% of the conservative group. Stents were used in a higher proportion of the invasive group (86% vs. 68%). Radial access was used in 86% and glycoprotein IIb/IIIa inhibitors in 9%.

The primary endpoint of death, reinfarction, stroke, or new ischemia at 1 year did not differ between treatment groups (20.9% for invasive vs. 27.3% for conservative, p = 0.18). However, there was a significant reduction in the secondary endpoint of death, MI, or stroke at 12 months with the invasive strategy (6.0% vs. 15.9%, p = 0.01). Death was 2.2% versus 3.0%, reinfarction was 3.0% versus 9.1%, stroke was 2.2% versus 5.3%, and recurrent ischemia was 15.0% versus 15.2%, respectively for invasive versus conservative therapy.

At 30 days, the composite of death, reinfarction, stroke, or new ischemia was lower in the invasive group (10% vs. 21%, p = 0.03), but there was no difference in death, reinfarction, or stroke (4.5% vs. 9.8%, p = 0.14). Total bleeding events at 30 days were similar in both groups (13% for invasive group vs. 14% for conservative group, p = 0.68), as was GUSTO severe bleeding (1.5% vs. 2.3%), moderate bleeding (0% vs. 2.3%), and minor bleeding (10% vs. 9.8%).

Interpretation:

Among TNK-treated patients with STEMI with very long transfer times to PCI hospitals, immediate transfer for PCI did not lead to a significant reduction in the primary composite endpoint of death, reinfarction, stroke, or new ischemia at 1 year compared with conservative, ischemia-guided treatment; however, a significant benefit was seen with the secondary endpoint of death, reinfarction, or stroke.

Previous studies such as DANAMI-2 have demonstrated that transfer of patients for primary PCI reduces the risk of death, reinfarction, or stroke compared with thrombolytic therapy. However, limited data are available for the comparison of immediate transfer for PCI compared with conservative ischemia-guided therapy in STEMI patients with very long transfer times who were previously treated with thrombolytic therapy. In the CARESS-in-AMI trial of STEMI patients treated with thrombolytic therapy, transfer for immediate PCI was associated with a reduction in the primary endpoint of death, reinfarction, or refractory ischemia at 30 days compared with conservative strategy, but transfer times (and presumably distances) were shorter than in NORDISTEMI, particularly in the conservative group.

There was a reduction in the secondary endpoint of death, reinfarction, stroke, or new ischemia at 30 days with immediate transfer in the present study, as well as a reduction in death, MI, or stroke at 12 months. Despite randomization to the conservative group, a large percentage of patients underwent PCI (71%), albeit in a delayed manner (median 3.0 days). The safety profile of the two strategies appeared similar, with no difference in bleeding by a variety of definitions. The low bleeding rates were probably attributable to the high use of radial access and low use of glycoprotein IIb/IIIa inhibitors.

References:

Bøhmer E, Hoffmann P, Abdelnoor M, Arnesen H, Halvorsen S. Efficacy and safety of immediate angioplasty versus ischemia-guided management after thrombolysis in acute myocardial infarction in areas with very long transfer distances: results of the NORDISTEMI (NORwegian study on DIstrict treatment of ST-Elevation Myocardial Infarction). J Am Coll Cardiol 2010;55:102-10.

Presented by Dr. Sigrun Halvorsen at the European Society of Cardiology Congress, Barcelona, Spain, August 2009.

Clinical Topics: Anticoagulation Management, Arrhythmias and Clinical EP, Dyslipidemia, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Prevention, SCD/Ventricular Arrhythmias, Lipid Metabolism, Interventions and Imaging, Computed Tomography, Nuclear Imaging, Hypertension

Keywords: Thrombolytic Therapy, Myocardial Infarction, Stroke, Follow-Up Studies, Tomography, Emission-Computed, Single-Photon, Ventricular Fibrillation, Ticlopidine, Fibrinolytic Agents, Percutaneous Coronary Intervention, Stents, Tachycardia, Ventricular, Enoxaparin, Catheterization, Tissue Plasminogen Activator, Hypertension


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