Cardiac surgery for opioid users linked to more complications, higher costs

People with opioid use disorder (OUD) who have heart surgery suffer in-hospital mortality at a rate on par with other patients but are more likely to experience complications and require longer hospital stays, according to a Nationwide Inpatient Sample analysis published in JAMA Surgery.

The study population included more than 5.7 million patients undergoing coronary artery bypass grafting (CABG), aortic surgery, valve surgery or a combination of those procedures from 1998 through 2013. Only 0.2 percent—11,359 in all—had OUD but the proportion of patients with OUD increased eightfold from the beginning of the study to the end (0.06 percent in 1998; 0.54 percent in 2013). This is congruent with the increasing burden of the opioid epidemic and the growing population of individuals with OUD in the U.S.

Researchers led by Krish C. Dewan, of the Cleveland Clinic Foundation, propensity matched 11,202 pairs of patients. They were well-matched on all other characteristics but one of the patients in each pair had opioid use disorder while the other didn’t.

The authors found the rates of in-hospital mortality were similar in patients with and without OUD, at 3.1 percent and 4.0 percent, respectively. However, opioid users required a median of 11 days in the hospital versus 10 in non-OUD patients, and they also accrued higher median costs per hospitalization ($49,790 versus $45,216).

The additional hospital costs likely stemmed from the higher prevalence in several complications for OUD patients, including:

  • Blood transfusion: 30.4 percent versus 25.9 percent
  • Pulmonary embolism: 7.3 percent versus 3.8 percent
  • Mechanical ventilation: 18.4 percent versus 15.7 percent
  • Prolonged postoperative pain: 2.0 percent versus 1.2 percent

“Trends in patient volume and morbidity reported in our study suggest that cardiac surgeons are likely to encounter this population of patients more often now than in the past and should be prepared to adequately manage the perioperative factors specific to them,” Dewan et al. wrote. “In urgent situations, patients need not be denied cardiac surgery because of their OUD status, although close postoperative monitoring is suggested.”

The authors also found that patients with OUD who were black or Hispanic had 71 percent greater and 107 percent greater odds of in-hospital mortality, respectively, than white patients. Cardiac arrhythmia and heart failure were also linked to nearly twice the risk of in-hospital mortality, while patients at centers that performed more than 200 surgeries per year had a 35 percent relative reduction in in-hospital death.

Dewan and colleagues speculated the prevalence of infective endocarditis among IV drug users led to a higher proportion of valve operations rather than CABG among patients with OUD. Infective endocarditis could have contributed to some of the complications that were more common among opioid users, the authors said, and the injection of opioid tablets intended for oral use may have also led to the higher rate of blood transfusions.

“Our study provides an overall clinical picture of outcomes that can be anticipated for the OUD population,” Dewan et al. wrote. “Our findings suggest that there may be value in incorporating OUD status into assessment algorithms (eg, the Society of Thoracic Surgeons risk calculator) to give surgeons and clinicians a clearer picture of operative outcomes.

“Future work examining specific operative factors and clinical endpoints will allow for more thorough guidelines that not only shape medical and surgical management of these patients but also prevent consequences of persistent opioid use in the operative setting.”