title: Increased risk of coronary artery bypass grafting for left ventricular dysfunction with dilated left ventricle.
abstract: The operative mortality and morbidity in patients with severe left ventricular dysfunction who undergo coronary artery bypass grafting (CABG) remain high. The low ejection fraction is the major risk factor for operative mortality. However, ejection fraction (EF) alone may not necessarily be an accurate predictor of operative mortality. We studied the correlation between indices of left ventricular volume and operative mortality. One thousand patients undergoing isolated coronary bypass operations were divided into three groups according to their preoperative ejection fraction. Fifty patients (group I) had severe left ventricular dysfunction (EF < or = 0.3), 56 patients (group II) had moderately left ventricular dysfunction (0.3 < EF < or = 0.4) and 894 patients (group III) had good left ventricular function (EF > 0.4). We analyzed the relationship between hospital mortality and left ventricular volume in 106 patients with an EF < or = 0.4.
  
  
  RESULTS
  Cardiac index was not significantly different among the three groups. The left ventricular end-diastolic pressure (LVEDP) and mean pulmonary artery pressure in groups I an II were higher than those in group III. The left ventricular end-diastolic volume (LVEDV) was 146 +/- 44 ml/m2 in Group I, 112 +/- 31 ml/m2 in Group II and 82 + 30 ml/m2 in Group III, respectively (Group I versus II, p < 0.05, Group I and II versus III, p < 0.01). The left ventricular end-systolic volume (LVESV) was 111 +/- 38 ml/m2 in Group I, 72 +/- 21 ml/m2 in Group II and 30 +/- 14 ml/m2 in Group III, respectively (Group I versus II, p < 0.05, Group I and II versus III, p < 0.01). The LVEDV and LVESV were higher in Group I than in Group II and both in Groups I and II were higher than in Group III. The hospital mortality of any cause before discharge was 8.0% (4/50) in Group I, 3.6% (2/56) in Group II, and 2.0% (18/894) in Group III. The mortality in Group I was higher than that in Group III, but the mortality between Groups I and II was not different. We assessed correlations between large left ventricle with left ventricular dysfunction and operative mortality in 106 patients with ejection fractions of < or = 0.4. The hospital mortality in patients with both under fraction 0.4 and an LVESV > or = 140 ml/m2 was 50% (4/8). This rate was higher than in patients with an LVESV between 80 and 140 ml/m2 (1.8%, 1/55) (p = 0.0006) and an LVESV less than 80 ml/m2 (2.3%, 1/43), (p = 0.0013). The hospital mortality in patients with an LVEDV > or = 200 ml/m2 was 67% (4/6). It was also higher than that in patients with an LVEDV between 200 and 120 ml/m2 (1.7%, 1/58), (p = 0.0001), and an LVEDV less than 120 ml/m2 (2.4%, 1/42), (p = 0.0004). We conclude that patients with a low ejection fraction and an elevated LVESV or LVEDV are at increased risk for hospital death following CABG.
authors.affiliation: Department of Surgery III, Nara Medical College, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kawachi
authors.forename: S
authors.initials: S
authors.lastname: Kitamura
authors.forename: J
authors.initials: J
authors.lastname: Hasegawa
authors.forename: T
authors.initials: T
authors.lastname: Kawata
authors.forename: S
authors.initials: S
authors.lastname: Kobayashi
authors.forename: K
authors.initials: K
authors.lastname: Mizuguchi
authors.forename: H
authors.initials: H
authors.lastname: Nishioka
authors.forename: S
authors.initials: S
authors.lastname: Taniguchi
authors.forename: Y
authors.initials: Y
authors.lastname: Kameda
authors.forename: Y
authors.initials: Y
authors.lastname: Yoshida
mesh_terms: D002306:Cardiac Volume; D001026:Coronary Artery Bypass / Q000401:mortality*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000150:complications / Q000601:surgery; D012307:Risk Factors; D013318:Stroke Volume; D015996:Survival Rate; D018487:Ventricular Dysfunction, Left / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*