Selective serotonin re-uptake inhibitors: risk of blood product transfusion and inotrope requirements in patients undergoing cardiac surgery

BACKGROUND: Patients undergoing cardiac surgery exhibit a high prevalence of concomitant depression. The first-line pharmacological treatment modality for depression includes selective serotonin re-uptake inhibitors (SSRIs). Despite their efficacy, SSRIs are not without their own side-effects. METHODS: We conducted a retrospective observational study to determine if preoperative SSRI therapy was associated with higher rates of perioperative blood product transfusion, and higher incidence of inotropic requirements in patients undergoing elective cardiac surgery. A total of 2,943 patients were included in the study. Patients undergoing emergency surgery or surgery without cardiopulmonary bypass (CPB) were excluded. Based on preoperative SSRI status patients were classed into either SSRI group (n=95), or non-SSRI group (n=2,848). Data was acquired from the Toronto Anesthesia Perioperative Outcomes Database. RESULTS: Baseline preoperative variables included age, sex, body surface area, smoking history, past medical history, preoperative medications, baseline hemoglobin, creatinine, and planned surgical procedures. Perioperative transfusion of blood products and inotropic utilization were collected. Univariate analysis showed that patients in SSRI group were more likely to be female, have history of congestive heart failure, preoperative anemia, and likelihood of having more complex surgery, received more inotropes and fresh frozen plasma, and were more likely to have chest reopening for bleeding. There was no difference in postoperative morbidity and mortality between the SSRI and non-SSRI groups. Separate statistical models were constructed to determine association between transfusion of red blood cells, fresh frozen plasma, platelets, composite inotrope use, and SSRI therapy. SSRI variable was not significant in any of the multivariate models, indicating the lack of evidence of association between the SSRIs and either blood product transfusion, or inotrope requirements. Significant predictors of blood product transfusion included smaller body surface area, female gender, older age, low baseline hemoglobin levels, elevated creatinine, increased CPB, presence of deep hypothermic circulatory arrest, complex cardiac surgery, history diabetes mellitus, and congestive heart failure. Predictors of inotrope use included older age, elevated creatinine, increased CPB time, history of diabetes mellitus, and congestive heart failure. CONCLUSIONS: The current study suggests that modifying preoperative therapy pertinent to SSRI treatment in patients undergoing elective cardiac surgery is not warranted.