- Between 2002 and 2014, patients with cirrhosis constituted only 0.3% of the total who underwent CABG in the United States
- Length of stay and hospitalization costs increased in patients with cirrhosis during that time
- Such patients experienced a higher rate of postoperative complications and in-hospital mortality than patients without cirrhosis
- Cardiac surgeons should take cirrhosis into account when selecting the approach to revascularization
Cardiac surgery is increasingly being performed in patients with hepatic cirrhosis. One study found that over a six-year period in Canada, the annual number of coronary artery bypass graft (CABG) surgeries increased by 4% in cirrhosis patients, who had an increased risk of morbidity and mortality afterward.
Igor F. Palacios, MD, director of Interventional Cardiology at Massachusetts General Hospital, recently led a team of cardiologists in conducting a similar study in the United States. In The American Journal of Cardiology, they report that although rates of in-hospital mortality are declining for patients with cirrhosis who undergo CABG, the risk of postoperative complications and death is higher.
The researchers gathered data from the Nationwide Inpatient Sample, which stores information on virtually all hospitalizations in the U.S. They identified 698,799 patients who underwent CABG between 2002 and 2014, of whom 2,231 (0.3%) had cirrhosis--the largest-ever report on a U.S. cohort of patients.
Of the patients with cirrhosis, the average age was 64 years, 74% were male and 63% were white. The average Charlson Comorbidity Index was 3.3.
The in-hospital mortality rate declined significantly over the study period, the research team found. Between 2002 and 2007, it was 11.3%, but between 2008 and 2014, it was 6.3% (P < .001).
Compared to non-cirrhosis patients, those with cirrhosis fared significantly worse during their hospitalizations on a number of measures including:
- Overall rate of in-hospital mortality (8.7% vs 2.8%)
- Incidence of cardiogenic shock while hospitalized (5.60% vs 3.76%)
- Length of hospital stay (13.7 days vs 9.87 days)
- Cost of hospitalization ($67,744 vs $50,084)
Of the patients with cirrhosis, 987 experienced a postoperative complication. The most common was hemorrhage requiring transfusion (14.5%), followed by respiratory failure (13%) and iatrogenic cardiac complications (10%).
In an observational study such as this one, the groups being compared often differ with regard to demographics, disease characteristics, comorbidities, surgical procedure and so on. The researchers performed a type of statistical analysis called propensity score matching, which attempts to account for potential confounders.
This analysis confirmed that, compared with non-cirrhosis patients, those with cirrhosis had higher rates of postoperative complications (43.9% vs 38.93%; P < .001) and in-hospital mortality (7.2% vs 4.07%; P < .001).
On multivariate analysis, the presence of ascites along with cirrhosis nearly tripled the risk of in-hospital mortality and it increased the rate of postoperative complications by five-fold. Other investigators have suggested avoiding cardiopulmonary bypass (CPB) during cardiac surgery in patients who have cirrhosis because contact with the tubing can stimulate factor VII and lead to a microembolism. In this cohort, CPB was used in 71% of patients and its use remained high throughout the study period. CPB was actually associated with decreased in-hospital mortality.
The authors note that liver dysfunction is not part of traditional cardiac risk assessment models. They advise cardiac surgeons to consider cirrhosis separately when selecting the approach to revascularization.
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