Impact of nicotine replacement therapy on postoperative mortality following coronary artery bypass graft surgery

Nicotine replacement therapy (NRT) has recently been associated with increased mortality in patients in medical intensive care units (ICUs). Although NRT is frequently used in cardiothoracic surgery patients, no safety data exist for use in this population.

To ascertain the impact of NRT on in-hospital mortality following coronary artery bypass graft (CABG) surgery.

This was a retrospective matched cohort pilot study in a 22-bed cardiothoracic surgery ICU. Patients prescribed transdermal NRT after CABG were randomly selected and matched to current smokers not prescribed NRT according to Acute Physiology and Chronic Health Evaluation II scores (N = 134). Data on comorbid conditions and pack-year history were also obtained. To compare these patients with nonsmoking patients, a larger unmatched population was also evaluated. The total number of patients prescribed NRT, current smokers not prescribed NRT, and nonsmokers who were evaluated in our study was 2057.

Sixty-seven NRT patients were well matched with 67 current smokers in terms of baseline demographics and procedures. Mortality was nonsignificantly higher in the NRT group versus the non-NRT smoker group (4.5% vs 0.0%; p = 0.080). In an evaluation of a larger population controlled for differences in baseline characteristics, an increase in mortality due to NRT was found (OR 6.06; 95% CI 1.65 to 22.21). In an a priori subgroup of the overall population, mortality was significantly higher in patients receiving NRT after off-pump CABG versus smokers not receiving NRT (OR 6.49; 95% CI 1.29 to 32.56).

The use of NRT in a postoperative CABG surgery population resulted in a significant increase in mortality when adjusted for baseline characteristics. Patients receiving NRT after off-pump cardiac surgery may be particularly susceptible. Additional evaluation in large patient cohorts with prospective controls is warranted.