title: The impact of a short interval ( < or = 1 year) between primary and reoperative coronary artery bypass grafting procedures.
abstract: Reoperative (redo) coronary artery bypass grafting is an efficient treatment for patients with progressive coronary artery disease and those with conduit failure. Previous studies have demonstrated that a short time interval between primary and redo coronary artery bypass grafting is associated with a significantly higher mortality rate. In the present report this particular group have been specifically evaluated. Between 1 January 1990 and 1 October 1994, 383 consecutive patients underwent redo coronary artery bypass grafting. Thirty-three patients (8.6%) were operated on at < or = 1 year (group 1) and 350 patients at > 1 year after the primary bypass (group II). The main indications for redo in group I were graft failure (58%), incomplete revascularization (39%) and progress of disease (3%); respective values in group II were 26% 15%, and 23%. In addition, 36% of patients in group II had combinations of complications. Patient characteristics did not differ between groups, except a higher incidence of insulin-dependent diabetes in group I (P < 0.05). There was a higher incidence of left main stem stenosis of > 70% in group I (P < 0.05). Group I patients had a longer aortic cross-clamping time and needed thromboendarterectomy and patching of coronary vessels more often than did those in group II (P < 0.05). The internal mammary artery had been more frequently used at the primary coronary artery bypass grafting in group I (P < 0.01). The overall mortality rate was 8.9%; that in group I was 18% and in group II, 8% (P < 0.05). There was a higher incidence of non-fatal myocardial infarction and a need for prolonged ventilatory support (> 24 h) in group I. Other postoperative complications did not differ. Significant risk factors for mortality in group I were preoperative Canadian Cardiovascular Society class > or = 3, unstable angina, need for urgent operation and left ventricular ejection fraction < 40%, and > or = 70% left main stem stenosis. In group II, the risk factors were: unstable angina, urgent operation, left ventricular ejection fraction < 40%, internal mammary artery not used at primary coronary artery bypass grafting and the need for coronary thromboendarterectomy. The 3-year survival and cardiac event-free survival did not differ between the groups. This study has confirmed that early redo coronary artery bypass grafting (< or = 1 year from primary bypass) is associated with an increased operative risk.
authors.affiliation: Cardiovascular Surgery Unit, Hôpital de la Tour, Meyrin-Geneva, Switzerland.
authors.forename: J T
authors.initials: JT
authors.lastname: Christenson
authors.forename: F
authors.initials: F
authors.lastname: Simonet
authors.forename: M
authors.initials: M
authors.lastname: Schmuziger
mesh_terms: D001026:Coronary Artery Bypass / Q000401:mortality*; D003327:Coronary Disease / Q000601:surgery*; D018572:Disease-Free Survival; D006801:Humans; D008323:Mammary Arteries / Q000637:transplantation; D018579:Patient Selection; D012086:Reoperation; D012306:Risk; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome