Prediction of perioperative complications in colorectal cancer via artificial intelligence analysis of heart rate variability

Abstract

Background: Heart rate variability (HRV) represents efferent vagus nerve activity, which is suggested to be related to fundamental mechanisms of tumorigenesis and to be a predictor of prognosis in various cancers. Therefore, this study hypothesized that HRV monitoring could predict perioperative complication (PC) in colorectal cancer (CRC) patients.

Aim: To investigate the prognostic value of HRV in hospitalized CRC patients.

Methods: The observational studies included 87 patients who underwent CRC surgical procedures under enhanced recovery after surgery programs in a first-class hospital. The HRV parameters were compared between the PC group and the non PC (NPC) group from preoperative day 1 to postoperative day (Pod) 3. In addition, inflammatory biomarkers and nutritional indicators were also analyzed.

Results: The complication rate was 14.9%. HRV was markedly abnormal after surgery, especially in the PC group. The frequency-domain parameters (including pNN50) and time-domain parameters [including high-frequency (HF)] of HRV were significantly different between the two groups postoperatively. The pNN50 was significantly greater at Pod1 in the PC group than that in the NPC group and returned to baseline at Pod2, suggesting that patients with complications exhibited autonomic nerve dysfunction in the early postoperative period. In the PC group, HFs were also enhanced from Pod1 and were significantly higher than in the NPC group; inflammatory biomarkers were significantly elevated at Pod2 and Pod3; the levels of nutritional indicators were significantly lower at Pod1 and Pod2; and the white blood cell count was slightly elevated at Pod3.

Conclusion: HRV is independently associated with postoperative complications in patients with CRC. Abnormal HRV could predicted an increased risk of postoperative complications in CRC patients. Continuous HRV could be used to monitor complications in patients with CRC during the perioperative period.

Keywords: Colorectal cancer; Complications; Heart rate variability; Perioperative period; Prediction.

Figure 1

Heart rate variability in a normal and abnormal state. A: A smart monitoring device for the collection of heart rate variability data; B: Poincaré scatter diagram in a relaxed and stressed state; C and D: Trend chart of time-domain parameters indicating the difference 24 hours before the operation to 3 days after the operation; E and F: Power spectral density analysis of the frequency domain indicates the difference between the non-perioperative complication group and the perioperative complication group. NPC: Non-perioperative complication; PC: Perioperative complication; HF: High-frequency; LF: Low-frequency.

Figure 2

Fluctuation of time-domain and frequency-domain heart rate variability analysis parameters during the perioperative period in the perioperative complication group and non-perioperative complication group. A: The SDNN data throughout the day; B: The data of pNN50; C: The data of RMSSD; D: The data of LF; E: The data of HF; F: The data of LF/HF. ^aP < 0.05, ^cP < 0.001, the NPC group vs PC group; ^gP < 0.05, ^hP < 0.01, ^lP < 0.001, vs Pre in the non-perioperative complication group; ^dP < 0.05, ^eP < 0.01, vs Pre in the perioperative complication group. SDNN: Standard deviation of N-N intervals; RMSSD: Mean of the squared differences between adjacent normal RR intervals; LF: Low-frequency band; HF: High-frequency band; NPC: Non-perioperative complication; PC: Perioperative complication; Pre: Preoperative day; Pod: Post-operative day.

Figure 3

Inflammatory markers during the perioperative period in patients undergoing laparoscopic radical colorectal cancer resection. A: White blood cell of patients in the non-perioperative complication group (NPC) and perioperative complication (PC) group; B: C-reactive protein levels of patients in the NPC group and PC group; C: Albumin levels of patients in the NPC group and PC group; D: Hemoglobin levels of patients in the NPC group and PC group. ^aP < 0.05, ^bP < 0.01, ^cP < 0.001, with the NPC group vs the PC group; ^hP < 0.01, ^lP < 0.001, vs Pre in the NPC group; ^dP < 0.05, ^eP < 0.01, ^fP < 0.001, vs Pre in the PC group. WBC: White blood cell; CRP: C-reactive protein; Hb: Hemoglobin; Pod: Post-operative day.