Preliminary evaluation of the role of transit-time flow measurement in coronary artery bypass grafting at Thong Nhat Hospital

Abstract

Background: Coronary artery bypass grafting (CABG) remains a cornerstone treatment for multivessel coronary artery disease. Transit-time flow measurement (TTFM) has been recognized as a reliable intraoperative tool for real-time assessment of graft quality. However, data on its prognostic value remain limited in Vietnam. Methods: We conducted a retrospective study of 42 patients who underwent isolated CABG at Thong Nhat Hospital between January 2023 and September 2025. Intraoperative graft flow was assessed using TTFM, and postoperative outcomes were compared between patients with a pulsatility index (PI) ≤ 3 and those with PI > 3.

Results: The mean age was 62.5 ± 8.6 years, and 85.7% were male. The left internal mammary artery and saphenous vein graft were most frequently used, in 95.2% and 76.2% of cases, respectively. Overall in-hospital mortality was 2.4%. The most common postoperative complications were pneumonia (14.3%) and heart failure (26.2%). Compared with PI ≤ 3, patients with PI > 3 had significantly longer postoperative stays (3.6 ± 1.7 vs. 2.2 ± 0.9 days; p = 0.017). Other adverse events, including heart failure (38.5% vs. 20.7%) and in-hospital mortality (7.7% vs. 0%), were more frequent in the PI > 3 group but did not reach statistical significance. No significant differences were observed in the rates of reoperation, wound infection, acute kidney injury, or stroke.

Conclusions: Intraoperative graft flow assessment with TTFM during CABG was associated with improved postoperative outcomes. A PI > 3 was linked to prolonged postoperative recovery and may reflect compromised graft quality, although it did not independently predict major adverse events.