Study Design

Study Design:

Patients Screened: (1) 13; (2, 3) 3,016
Patients Enrolled: (1) 13; (2, 3) 1,493
NYHA Class: not given
Mean Follow Up: (1) 24 hours; (2, 3) 1 year
Mean Patient Age: (1) 58.5 years; (2, 3) 56.1 years
Female: (1) 31%; (2, 3) 55%
Mean Ejection Fraction: not given

Patient Populations:

(1) occlusion of a lobar artery or at least two segmental arteries evident at angiography
(2, 3) risk factors, signs, symptoms or laboratory findings which were unexplained and suggestive of acute pulmonary embolism

Exclusions:

(1)
Shock (systolic blood pressure <80 mmHg despite vasopressor treatment)
Major disability from pulmonary embolism
Pregnancy at any age and the first ten days postpartum
Uncontrolled hypertension (diastolic blood pressure >110 mmHg by several measurements or hypertensive retinopathy with hemorrhages or exudates
Present bleeding disorder
History of gastrointestinal (GI) bleeding within six months or symptoms of active GI diseases which have a propensity to bleed
Renal insufficiency (creatinine >3.0 mg/dL)
Severe hepatic insufficiency
Evidence of a lesion known to be associated with intracranial hemorrhage (including cerebral malignancy, aneurysm, abscess or head trauma)
History of cerebrovascular disease
Neurosurgery within six months
Uncontrolled hypocoagulable state (including coagulation factor deficiencies, platelet abnormalities or other spontaneous hemorrhagic or purpuric phenomena; oral anticoagulation with warfarin; therapy with thrombolytic agent within the past three days [therapy with aspirin on the same day was a relative contraindication])
Severe trauma within two months
Any surgical or invasive procedure (including biopsies, deep tissue aspirations, depot injections, unsuccessful attempts at central line placement or removal of successfully placed central lines [e.g., subclavian or internal jugular] within ten days of study entry; previous arterial punctures of femoral or brachial are relative contraindications)
Placement of central venous line within 48 hours
Ophthalmologic surgery within six weeks
Cardiopulmonary resuscitation (one minute or more of external cardiac massage) within two weeks of study entry
Previous participation in the PIOPED rt-PA randomized trial
Psychological or physical inability to participate

(2, 3)
Scan requests cancelled
Scans requested for research purposes
Diagnosis other than acute pulmonary embolism
Contraindications to angiography
Pregnancy
Creatinine level >260 æmol/L
Hypersensitivity to contrast material
Signed informed consent (once approached for the study, patients with recurrences of acute pulmonary embolism were not approached for recruitment a second time.)

Primary Endpoints:

Fragment-D dimers (in vivo clot lysis indicator), total pulmonary resistance.
Death, suspicion of recurrent pulmonary embolism, complications of angiography or therapy.

Secondary Endpoints:

Occlusion grade (1-3), size grade (0.1, 0.3, 1 to 3, 6)
Consensus in the assessment of the probability of pulmonary embolism; assessment of the probability of pulmonary embolism (high-, intermediate-, low-, very low-, and normal-probability) after one year of follow-up

Drug/Procedures Used:

rt-PA, in the study group 80mg IV at a rate of approximately 1 mg/minute for first 3 patients then 64mg for fourth patient (hemorrhage interrupted intended 80mg dose) and finally dose reduced to 40mg for the remaining 5 patients in study group to redu

Concomitant Medications:

76% sodium and meglumine diatrizoates, 40 to 50 ml injected either in the left or right pulmonary artery; technetium 99m (^99mTc) macroaggregated albumin, 4 mCi (millicuries)
xenon 133 (¹³³Xe), 15 to 30 mCi (millicuries); technetium 99m (^99mTc) macroaggregated albumin, 4 mCi