Coronary artery bypass grafting in patients with left ventricular ejection fraction of 30% or less

Abstract

Background: The results of a merely pharmacological therapy in patients with advanced left ventricular dysfunction are unsatisfactory. Coronary artery bypass grafting is frequently the only therapeutic option, but ventricular dysfunction is generally considered to be a risk factor.

Aim: To find out the frequency of coronary artery bypass grafting and its outcome in patients with a ejection fraction of 30% or less who were operated on at a single institution.

Methods: Between January 1st, 1996 and October 30th, 1999, 90 patients (4.6% of all patients operated on due to of coronary artery disease) with EF of 30% or less underwent coronary artery bypass grafting. This group consisted of 12 women and 78 men at an average age of 60.2 +/- 9.4 years (range, 33 to 78 years); 75.6% patients were in functional class III or IV and 80.0% had three-vessel disease. On the average, 2.5 grafts per patient were implanted, the left internal mammary artery was used in 24.4% patients, and 10.0% of patients had cardiac surgery without cardiopulmonary bypass.

Results: Hospital mortality was 10%. The main cause of death was cardiac or multiorgan failure. Low cardiac output syndrome and supraventricular dysrrhythmias were the most common postoperative complications. Advanced age and low cardiac output syndrome were found to be risk factors of early mortality. Five other patients died during the follow-up (4 to 48 months). One- and three-year survival rate were 83.1% and 81.9%, respectively. Ejection fraction improved during the follow-up from 27.5% to 33.7%. The improvement was more pronounced in patients in whom preoperative end-diastolic diameter of the left ventricle was below 70 mm, and in patients with two and more hibernating segments on dobutamine stress echo.

Conclusions: Successful results of surgical revascularization in patients with severe impairment of left ventricular function can be achieved by careful selection of patients (the presence of viable myocardium is necessary) and management. Early mortality and morbidity was higher than in patients with normal ventricular function. Age and low cardiac output syndrome were revealed as risk factors of early mortality. Long-term prognosis for hospital survivals was satisfactory. (Tab. 5, Fig. 1, Ref. 13.)