Background: The diagnosis of viable myocardium in the
setting of ischemic left ventricular systolic dysfunction might
indicate which patients have the greatest prognostic benefit from
myocardial revascularization. Single-photon emission CT (SPECT)
thallium-201 (201Tl) scintigraphy for the detection of
viable myocardium is widely available in the community, but outcome
data using this imaging modality are limited.
Thirty-seven patients (mean [± SD] age, 62 ± 12 years) with
ischemic left ventricular dysfunction (mean ejection fraction,
30 ± 9%) initially referred for rest-redistribution SPECT thallium
scintigraphy were evaluated 29 ± 19 months after coronary bypass
surgery (n = 15) or medical therapy alone (n = 22). The
relationship among myocardial viability, mode of therapy, and long-term
prognosis was evaluated.
myocardial viability (defined as a viability index [VI] of > 0.5)
was present in 19 patients. Among patients with a VI > 0.5, the
48-month actuarial event-free survival was 89 ± 10% for patients
undergoing surgical revascularization, compared with 0% for the
medical treatment subgroup (p = 0.005). In contrast, patients in the
low-viability subgroup tended to have intermediate event-free survival
rates, which were not statistically different for patients receiving
either surgical (62 ± 21%) or medical therapy (50 ± 14%;
p = 0.55).
Conclusions: Survival is significantly
more favorable for surgically revascularized patients with ischemic
left ventricular dysfunction and myocardial viability as detected by
SPECT 201Tl scintigraphy.