title: Long-term prognosis and a prediction model for acute bowel ischaemia following cardiac surgery.
abstract: OBJECTIVE
  Bowel ischaemia following cardiac surgery is associated with a high postoperative mortality. No scoring system exists as yet to predict this complication following surgery. In addition, the long-term survival is not known. We sought to evaluate in-hospital outcomes and long-term outcomes in bowel ischaemia following cardiac surgery. We also sought to devise a simple risk prediction model for this catastrophic entity.
  
  
  METHODS
  This was a retrospective study of data entered prospectively into our cardiac surgical database between July 1999 and May 2014. We compared the short- and long-term outcomes of patients who developed bowel ischaemia following cardiac surgery with those who did not develop bowel ischaemia using propensity-matched analysis. We developed a prediction model for bowel ischaemia from logistic regression.
  
  
  RESULTS
  In total, 13 853 patients underwent cardiac surgery. Of these, 85 had confirmed bowel ischaemia following surgery. The in-hospital mortality rate for those with bowel ischaemia was 60%, while in those without bowel ischaemia, the mortality rate was 3% (P < 0.0001). In those bowel ischaemia patients who had a laparotomy for corrective surgery, the in-hospital mortality was significantly less compared with those who did not have a laparotomy (39.2 vs 91.2%, P < 0.0001). The long-term survival for bowel ischaemia at 2, 6 and 10 years was 35% (±5), 31% (±5) and 26% (+/6), respectively. Multivariable analysis revealed that advanced age at surgery, peripheral vascular disease, intra-aortic balloon pump usage, NYHA IV and postoperative atrial fibrillation were the significant (P < 0.005) determinants of developing postoperative bowel ischaemia. We developed a model to predict bowel ischaemia and validated it within our population (c-index = 0.781).
  
  
  CONCLUSIONS
  We have shown that whilst bowel ischaemia carries a higher short-term mortality, the long-term mortality is not significantly greater for those few who survive to discharge. We have developed a simple prediction model to identify those at high risk of developing bowel ischaemia following cardiac surgery in order to optimize perioperative strategies in future.
authors.affiliation: Department of Cardiothoracic Surgery, Castle Hill Hospital, Cottingham, UK priyadariyaratnam@yahoo.co.uk.
authors.forename: Priyadharshanan
authors.initials: P
authors.lastname: Ariyaratnam
authors.affiliation: Department of Cardiothoracic Surgery, Castle Hill Hospital, Cottingham, UK.
authors.forename: Ajith
authors.initials: A
authors.lastname: Vijayan
authors.affiliation: Department of Cardiothoracic Surgery, Castle Hill Hospital, Cottingham, UK.
authors.forename: Alexander R
authors.initials: AR
authors.lastname: Cale
authors.affiliation: Department of Cardiothoracic Surgery, Castle Hill Hospital, Cottingham, UK.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Cowen
authors.affiliation: Department of Cardiothoracic Surgery, Castle Hill Hospital, Cottingham, UK.
authors.forename: Yama
authors.initials: Y
authors.lastname: Haqzad
authors.affiliation: Department of Cardiothoracic Surgery, Castle Hill Hospital, Cottingham, UK.
authors.forename: Sendhil
authors.initials: S
authors.lastname: Balasubramanian
authors.affiliation: Department of Cardiothoracic Surgery, Castle Hill Hospital, Cottingham, UK.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Loubani
mesh_terms: D000208:Acute Disease; D000368:Aged; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D008297:Male; D065666:Mesenteric Ischemia / Q000453:epidemiology / Q000209:etiology*; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D006113:United Kingdom / Q000453:epidemiology
keywords: Bowel ischaemia; Cardiac surgery; Propensity-matched analysis; Survival analysis