Valor pronóstico del SPECT de perfusión miocárdica en pacientes coronarios con enfermedad multivaso y disfunción ventricular izquierda, comparando revascularizados y no revascularizados

Abstract

We investigated the prognostic value of 99mTc-Tetrofosmin myocardial SPECT (99mTc-TF) in dysfunctional multivessel coronary disease patients who underwent revascularization (RV) or only medical treatment (MT). In 78 coronary patients with 2-3 diseased vessels and left ventricular ejection fraction (EF) <= 40% (24 10%), we have assessed the extension of the stress perfusion defect, and percent of reversibility (R) by quantification of stress-rest myocardial SPECT 99mTc-TF bull's eyes (2 days-protocol), lung/heart ratio (LH) calculated in the original stress SPECT images, and EF by equilibrium radionuclide ventriculography obtained at 24 h. A R value >= 8% was used to identify viable (V) patients. A total of 28 patients underwent RV and 50 only received MT. After a mean follow-up of 22.9 20 months (3-60), they were considered as coronary events (CE): cardiac death, non-fatal infarction and heart transplant. CE rate was 20.5% (16/78). No significant differences were found in the pre-revascularization study characteristics, except a significantly higher mean R value in RV (10.6 9.5%) than in MT patients (6.4 7.8%) p: 0.03, and the main difference was that RV patients showed less CE 2/28 (7%) than the MT group 14/50 (28%) p: 0.02. The CE rate was lower in V patients who underwent RV (6%) than in V patients with MT (45%) p: 0.03, but no significant difference was obtained in non-V patients between RV (7%) and MT (16%) groups. In viable patients, the corresponding survival curves (Kaplan-Meier) showed a CE-free survival at 5 years of 79% in patients RV and of 42% in MT patients, p: 0.03, without significant difference in non-V patients. Patients with viable myocardium by myocardial SPECT have a good prognosis after revascularization, and show higher risk of CE if they are only medically treated. Myocardial viability is an indispensable assessment in prognosis evaluation and, above all, in therapeutic decision making in dysfunctional multivessel coronary disease patients.