Risk stratification of single or double vessel coronary artery disease and impaired left ventricular function using exercise radionuclide angiography.
Patients with 3-vessel coronary artery disease (CAD) and normal left ventricular (LV) function have a worse prognosis if they manifest ischemia during exercise testing. The present study determines if exercise radionuclide angiography can aid in the risk stratification of patients with 1- or 2-vessel CAD and impaired LV function (ejection fraction less than 50%). Sixty-five consecutive patients with these findings were followed for a median duration of 24 months (range 12 to 49). Eleven of the 65 patients (17%) had severely ischemic exercise radionuclide angiograms, defined as: a decrease in ejection fraction with exercise; greater than or equal to 1.0 mm of ST-segment depression; and peak exercise workload less than or equal to 600 kg-m/min. During follow-up 11 patients had initial significant cardiac events: 4 cardiac deaths, 1 cardiac arrest, 4 myocardial infarctions and 2 bypass or angioplasty procedures for unstable angina greater than or equal to 3 months after the exercise study. Four of 11 patients (36%) with severely ischemic exercise radionuclide angiograms had events, compared to 7 of 54 patients (13%) without ischemic radionuclide angiograms. Event-free survival at 18 months was 73% for patients with severe exercise ischemia versus 92% for those without ischemia (p less than 0.05). Univariate analysis showed that severe ischemia on radionuclide angiography was the only variable of several tested that significantly predicted future cardiac events (chi-square = 8.16, p less than 0.005). Among patients with 1- or 2-vessel CAD and impaired resting LV function, severe ischemia on exercise radionuclide angiography identifies a subgroup at high risk for future cardiac events.
Miller
T D
TD
Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic and Foundation, Rochester, Minnesota 55905.
Taliercio
C P
CP
Zinsmeister
A R
AR
Gibbons
R J
RJ
D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000401:mortality; D005080:Exercise Test; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011875:Radionuclide Angiography; D012307:Risk Factors; D013318:Stroke Volume; D013997:Time Factors