Dipyridamole thallium-201 scintigraphy for early risk stratification of patients after uncomplicated myocardial infarction.
OBJECTIVE
To determine the safety and prognostic value of dipyridamole thallium-201 scintigraphy performed in patients within three to five days of acute myocardial infarction, including those receiving thrombolytic treatment.


METHODS
A prospective study of dipyridamole thallium-201 scintigraphy in patients early after acute myocardial infarction.


METHODS
University hospital.


METHODS
200 patients who were clinically uncomplicated at day 3 after infarction, 92 (46%) of whom had received thrombolysis.


METHODS
Incidence of cardiac death, non-fatal reinfarction, readmission to hospital for unstable angina, or non-elective revascularisation procedure within six months' follow up.


RESULTS
No patient had a serious complication from the dipyridamole study. At six month follow up, 55 patients (28%) had suffered a defined cardiac event. Patients who received thrombolysis had the same extent of thallium-201 redistribution and the same occurrence of subsequent cardiac events as those not receiving thrombolysis. Patients who subsequently had an event had more myocardial segments showing thallium-201 redistribution than event free patients: 2.7 (SD 1.9) v 1.2 (1.4), respectively (p < 0.001). Among all clinical and scintigraphic variables, multivariate analysis identified the extent of thallium-201 redistribution as the only independent predictor of outcome (p < 0.001). Among 63 patients (32%) of the study cohort who showed more than two myocardial segments with thallium-201 redistribution, the adjusted risk ratio for a cardiac event was 7.5 (95% confidence interval 2.9 to 19.1) compared with patients without any redistribution.


CONCLUSIONS
Dipyridamole thallium-201 scintigraphy can be performed safely within a few days of the event in patients with uncomplicated myocardial infarction, including those who received thrombolysis, and can identify a subgroup of patients at high risk of future ischaemic events.
Hung
J
J
Department of Medicine, University of Western Australia, Perth, Australia. jhung@cyllene.uwa.edu.au
Moshiri
M
M
Groom
G N
GN
Van der Schaaf
A A
AA
Parsons
R W
RW
Hands
M E
ME
D000368:Aged; D004176:Dipyridamole; D005260:Female; D005500:Follow-Up Studies; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000628:therapy; D011379:Prognosis; D011446:Prospective Studies; D015635:Radionuclide Ventriculography; D012008:Recurrence; D012044:Regression Analysis; D013794:Thallium Radioisotopes; D015912:Thrombolytic Therapy; D014665:Vasodilator Agents
D013794:Thallium Radioisotopes; D014665:Vasodilator Agents; D004176:Dipyridamole