Do Flow and Pulsatility Index within the Accepted Ranges Predict Long-Term Outcomes after Coronary Artery Bypass Grafting?

Abstract

Transit-time flow measurement (TTFM) is the gold standard for intraoperative detection of graft failure. Several reports show that TTFM and distal coronary bed quality (DCBQ) may also be useful for midterm detection of graft failure. Nonetheless, there are no data regarding their predictive role on long-term outcomes. Patients with three-vessel disease who underwent isolated coronary artery bypass grafting (CABG) in 2006 and received at least one graft to the left anterior descending artery (LAD) or to the first obtuse marginal (OM1) or posterior descending artery (PDA) were included. Baseline characteristics, mean graft flow, pulsatility index, and subjective impression of DCBQ for each coronary territory were collected. Long-term cardiovascular (CV) and overall survival, operative mortality, and new percutaneous coronary intervention (PCI) were evaluated. A total of 177 patients underwent isolated CABG. The OM1 was grafted in 131 patients, the LAD in 169 patients, and the PDA in 100 patients. Neither DQCB nor TTFM were predictors for new PCI. Independent predictors for overall survival were age, previous acute myocardial infarction (AMI), and DQCB of OM1 (odds ratio [OR] = 2.97; 95% confidence interval [CI]: 1.15-7.71). Age, previous AMI, and DCBQ of OM1 (OR = 2.5; 95% CI: 1.39-4.81) were independent predictors for CV survival. TTFM on patients with functioning grafts does not predict long-term survival or performance of new PCI. Subjective evaluation of distal coronary bed, especially of the OM1, has a strong impact on long-term outcomes.

Improving coronary artery bypass grafting: a systematic review and meta-analysis on the impact of adopting transit-time flow measurement

“…Twelve studies evaluated short-term outcomes in relation with TTFM parameters (Supplementary Material, Table S4) [8, 13, 25, 27, 54, 62, 69, 71–75]. Bauer et al [75] compared CABG with TTFM versus without TTFM and found an increased rate of intraoperative redo-anastomoses, which coincided with significantly lower incidences of ventricular fibrillation, perioperative MI and postoperative mortality when TTFM was performed.…”

“…However, observational studies showed the positive predictive capability of TTFM on intermediate-term clinical outcomes, such as major adverse cardiac events, mortality, intra-aortic balloon pump placement or cardiac enzyme release [8, 75]. Other studies reported data that showed no correlation between TTFM parameters and mid-term hospital readmission (during 1.8-year follow-up) [25], survival after 3.8 years [74] or even long-term survival (7.8 ± 0.2 years, Supplementary Material, Table S4) [13].…”

Intraoperative graft patency validation: Friend or foe?

“…8,20 Several studies have shown no correlation between TTFM and clinical outcomes. 21,22 However, Kieser and colleagues 23 reported a correlation between PI values and postoperative major adverse cardiac events but had a greater overall mortality of 4.8% than typically anticipated. 23 The randomized Graft Imaging to Improve Patency (GRIIP) trial 22 found no differences in graft failure at 1 year by coronary angiography between the control group and patients who underwent intraoperative TTFM.…”

“…Several studies have shown no correlation between TTFM and clinical outcomes. 21 , 22 However, Kieser and colleagues 23 reported a correlation between PI values and postoperative major adverse cardiac events but had a greater overall mortality of 4.8% than typically anticipated. 23 …”

Coronary Artery Bypass Grafting Transit Time Flow Measurement: Graft Patency and Clinical Outcomes

“…Thus far, most TTFM assessment studies have focused largely on its association with patency. As with the REQUEST study, few studies examined clinical outcome 17,18 and most are limited by the lack of a concurrent comparison group. An exception is the study by Singh and colleagues 6 that randomly allocated 156 patients to two equal groups, comparing TTFM use and nonuse.…”