Transit Time Flow Measurement (TTFM) used in study of Antiplatelet Therapy in Coronary Artery Endarterectomy


This month the Cardiac case highlights a recent study performed at the University hospital in Essen, Germany and published in Journal of Cardiovascular Development and Disease (JCDD). The study is titled “Role of Antiplatelet Therapy in Patients with Severe Coronary Artery Disease Undergoing Coronary Artery Endarterectomy within Coronary Artery Bypass Surgery”.

Dual antiplatelet therapy (DAPT) is indicated as “could protect against fast intimal ingrowth after injuring procedures by PCI” by the ESC/EACTS- and ACC/AHA-guidelines. The 2017 EACTS guidelines on perioperative medication also recommends considering DAPT for patients undergoing coronary bypass grafting (CABG).

With these guidelines as background, the featured study aimed to review the effect of single-APT or dual-APT on a population of 353 patients undergoing coronary artery endarterectomy (CEA) as part of a CABG procedure.

Surgical Procedure

All surgeries were performed on-pump using cardiopulmonary bypass (CPB), under arrested heart after administration of crystalloid cardioplegia. Coronary endarterectomy was performed in the case of total or sub-total occlusion (i.e., if the vessel’s lumen < 1.25 mm). The applied CEA-technique was a modified closed-traction technique and consisted of five steps. A proper removal of the atheroma was considered when a smoothly tapered cylinder was extracted (Figure 1), otherwise a distal second incision and subsequent anastomosis was performed to guarantee adequate revascularization of the peripheral segments. After creation of the anastomosis with the chosen graft, transit time flow measurement (TTFM) was performed to control the graft function (Figure 1).

With regards to the flow measurements the study says:

In this study, coronary bypass flow was significantly higher in DAPT patients than in SAPT patients (65 (45–90) vs. 57 (35–80) mL/minute, p = 0.028), as proven by TTFM measurements after discontinuation of CPB, even though this finding was only observed retrospectively, graft flow should be considered for long-term graft patency evaluation. As expected, most of the occluded grafts were venous (37 out of 45 of the total grafts and 15 out of 17 of the CEA grafts), which corresponds to previous reports observing better arterial graft patency in comparison to the venous ones [28,29]. A probable explanation for graft patency might be the role of early DAPT therapy starting at the first postoperative day using ASA + P2Y12-inhibitor for six months.

Long-term outcomes reported in the study demonstrated a significant lower incidence of overall mortality (19% vs. 51%, p < 0.0001) and MACCE (24.5% vs. 58.2%, p < 0.0001) in the DAPT versus SAPT group, respectively, as reported in Kaplan Meier curves for the estimation of survival and freedom from MACCE (Figure 4).


Study Conclusion

Coronary endarterectomy allows revascularization in end-stage CAD when the myocardium is still viable. The use of dual APT after CEA for at least six months seems to improve mid-to-long-term patency rates and survival and reduced the incidence of major adverse cardiac and cerebrovascular events.

The full article is available online here:

This study highlights how TTFM data can provide valuable insight also when evaluating the impact of different medical practices.

If you find the topic of interesting, we also recommend these two papers:

Hynes, C. and Trachiotis, G. (2015) A Single Center Experience with Coronary Endarterectomy and Vein Patch Reconstruction. World Journal of Cardiovascular Surgery, 5, 11-17. doi: 10.4236/wjcs.2015.52003.

Trachiotis GD. Early Antiplatelet Therapy in Coronary Artery Bypass Grafting a Calculated Benefit. Innovations. 2010;5(5):317-325. doi: 10.1097/imi.0b013e3181f63b30



Balaj, I.; Jakob, H.; Haddad, A.; Mourad, F.; Haneya, A.; Ali, E.; Ryadi, N.; Thielmann, M.; Ruhparwar, A.; Shehada, S.-E. Role of Antiplatelet Therapy in Patients with Severe Coronary Artery Disease Undergoing Coronary Artery Endarterectomy within Coronary Artery Bypass Surgery. J. Cardiovasc. Dev. Dis. 2023, 10, 112.