The long-term incidence of chronic post-surgical pain after coronary artery bypass surgery - A prospective observational study

Background: Chronic post-surgical pain (CPSP) represents a significant issue for many patients following surgery; however, the long-term incidence and impact have not been well described following cardiac surgery. Our aim was to characterize CPSP at least 5 years following coronary artery bypass grafting (CABG) surgery.

Methods: This prospective observational study investigated a cohort of patients from a larger trial investigating cognitive outcomes following CABG surgery, with 89 of 148 eligible patients (60.1%) assessed for CPSP at a mean (standard deviation [SD]) of 6.8 [1.2] years. Questionnaires interrogated pain presence, intensity, location, neuropathic characteristics, Geriatric Depression Scale scores (GDS) and instrumental activities of daily living (IADL).

Results: CPSP was described in 21/89 (23.6%), with 10 rating it as moderate to severe. Six of the CPSP patients (29%) met criteria for neuropathic pain (6.7% overall). The highest rate of CPSP was associated with the leg surgical site (chest 12/89 [13.5%], arm 8/68 [11.8%] and leg (saphenous vein graft-SVG) 11/37 [29.7%]; χ² = 6.523, p = 0.038). IADL scores were significantly lower for patients with CPSP (mean [SD]: 36.7 [1.6] vs. no CPSP 40.6 [0.6]; p = 0.006). Patients had GDS scores consistent with moderate depression (GDS >8) in 3/21 (14.3%) with CPSP, versus 3/68 (4.4%) non-CPSP patients (χ² = 3.20, p = 0.073).

Conclusions: This study identified a CPSP incidence of 23.6% at a mean of 6.8 years after CABG surgery, with the highest pain proportion at SVG harvest sites. CPSP was associated with neuropathic pain symptoms and had a significant impact on IADLs. This emphasizes the need for long-term follow-up of CABG patients.

Significance: This study highlights the impact of CPSP 7 years following cardiac surgery and highlights the effect of surgical site, neuropathic pain and the importance of including pain assessment and management in the long-term follow-up of cardiac surgical patients. Strategies to address and prevent chronic pain following cardiac surgery should be further explored.