BRS and Outcomes in Cardiothoracic Surgery

The purpose of this study is to determine if preoperative baroreceptor sensitivity (BRS)
correlates with major outcomes after cardiac and thoracic surgery, including acute and
chronic pain, atrial arrhythmias, and cognitive function. To test this hypothesis,
approximately 95 patients will be enrolled, and spontaneous baroreceptor sensitivity will be
measured prior to surgery as well as immediately postoperatively. Outcomes will include acute
pain using the numeric rating scale, Brief Pain Inventory, and Gracely Box Scale administered
preoperatively, on postoperative days 1 and 2 and by phone at 6-weeks postoperatively.
Chronic pain will be assessed at 6-month follow-up visit via hyperalgesia testing using Von
Frey filaments. Postoperative atrial arrhythmias will be assessed by review of postoperative
telemetry, the electronic medical record, and ECG performed prior to discharge. Finally,
cognitive function will be assess via Mini-Mental State examination administered preoperative
and at the 6-month follow-up visit. Association between BRS and the outcomes of interest will
be tested with regression models adjusted for appropriate covariates. Significance threshold
alpha will be adjusted for the number of statistical tests using the Bonferroni correction.
Our hypothesis is that patients with impaired preoperative BRS will have an increased
incidence of acute and chronic postoperative pain, atrial fibrillation, and cognitive decline
after surgery.

Inclusion Criteria:

- >= 18 years of age

- Undergoing cardiac (coronary artery bypass grafting [CABG], CABG + valve, or valve
only) or thoracic (video-assisted thoracoscopic [VATS] approach to lobectomy) surgery

Exclusion Criteria:

- Any preexisting pain condition (defined as pain of >=3 months duration prior to
enrollment)

- Pain at the time of enrollment interview

- Need for preoperative analgesics

- Preexisting chronic or paroxysmal atrial fibrillation

- Preexisting atrial or ventricular arrhythmia

- Need for preoperative anti-arrhythmic medication

- History of symptomatic cerebrovascular disease (e.g., prior stroke) with residual
deficits

- Alcoholism (>2 drinks/day)

- Psychiatric illness (any clinical diagnosis requiring therapy)

- Drug abuse (any illicit drug use in the preceding 3 months before surgery)

- Hepatic insufficiency (liver function tests > 1.5 times the upper limit of normal)

- Severe pulmonary insufficiency (home oxygen)

- Renal failure (serum creatinine >2.0 mg/dL)

- Non-English speaking

- Unable to read

- Participants who score <24 on baseline Mini Mental State examination