Functional recovery after coronary artery bypass grafting in patients withsevere left ventricular dysfunction and preserved myocardial viability in the left anterior descending arterial territory as assessed by thallium-201myocardial perfusion imaging

To evaluate the functional recovery after coronary bypass surgery in patien ts with severe left ventricular (LV) dysfunction (ejection fraction (EF) le ss than or equal to 35%), 100 consecutive patients with viable myocardium i n the territory supplied by the left anterior descending artery (LAD) under went coronary bypass grafting. In addition, cardiac catheterization and sin gle-photon emission computed tomography (SPECT) perfusion imaging with thal lium-201 were repeated 1-year postoperatively. Although 12 patients with se vere LV dysfunction were preoperatively in a worse New York Heart Associati on functional class (3.1+/-0.7 vs 2.4+/-0.8; p<0.01), had a higher incidenc e of heart failure (10/12 vs 14/88; p<0.001) and had a worse LVEF (29+/-5 v s 61+/-14%; p<0.001) compared with 88 patients without: severe LV dysfuncti on, the operative mortality was similar in the 2 groups (1/12 vs 2/88; p=NS ). The postoperative NYHA functional class in the patients with severe LV d ysfunction was similar to that in the patients without such dysfunction (1. 6+/-0.7 vs 1.3+/-0.6; p=NS). In addition, the 1-year postoperative study re vealed a significant improvement in the thallium defect score in both the L AD territory (1.7+/-1.2 to 0.7+/-1.0, p=0.01) and all the territories (5.2/-2.2 to 3.2+/-1.9, p=0.002) in patients with severe LV dysfunction, wherea s no improvement in defect score was found in either of these territories i n those without severe LV dysfunction (LAD: 0.6+/-1.4 to 0.4+/-1.2, p=NS; A ll: 1.9+/-2.2 to 1.8+/-2.0, p=NS). Furthermore, a marked 1-year postoperati ve improvement (15-24%; 95% confidence interval) in LVEF (29+/-5 to 48+/-10 %, p<0.001) was demonstrated in patients with severe LV dysfunction, but no t in those without such dysfunction (60+/-13 to 61+/-11%, p=NS) These resul ts indicate that myocardial viability in the LAD territory, as demonstrated by thallium-201 SPECT perfusion imaging, predicts a significant improvemen t in functional class and LVEF of at least 10% or more after coronary arter y bypass grafting in patients with severe LV dysfunction.