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Harik et al. Vessel Plus 2023;7:30 https://dx.doi.org/10.20517/2574-1209.2023.124 Page 11 of 16

pump CABG (157 of whom had imaging at one-year follow-up) and found the proportion of non-occluded
[87]
grafts was similar between groups (on-pump 95%, off-pump 89%; P = 0.09) . A recent study-level meta-
[88]
analysis of 16 RCTs, 6,227 patients, and 11,641 grafts found that off-pump CABG was associated with a
higher risk of graft failure (relative risk 1.31, 95%CI: 1.17-1.46; P < 0.001); this increased risk was
pronounced at follow-up one year after surgery and dissipated and longer follow-up. In addition, several of
the included studies had high (> 10%) crossover rate, possibly skewing results and suggesting a question of
physician expertise with off-pump CABG.

MEDICAL THERAPY, CLINICAL OUTCOMES, AND GRAFT PATENCY
The role of medical therapy for CABG to maximize the benefits of revascularization cannot be overstated,
irrespective of the choice of conduit. Antithrombotic regimens after CABG, as discussed in greater detail
earlier in the text, play a crucial role in maintaining graft patency. The use of postoperative statins and
antihypertensive therapy has been associated with improved clinical outcomes after CABG in numerous
large-scale, retrospective studies [89-91] . Statin use has also been associated with a lower incidence of vein graft
occlusion in CABG patients [91,92] , although the optimal dosing is not yet fully elucidated. The Aggressive
[93]
Cholesterol Therapy to Inhibit Vein Graft Events (ACTIVE) trial found that there was no difference in
the incidence of vein graft occlusion at one-year follow-up between patients randomized to high-dose
(80 mg, 11.4%) or low-dose (10 mg, 12.9%; P = 0.85) statin.

CONDUIT SELECTION IN WOMEN
Women have well-reported worse outcomes than men after CABG, including higher mortality and higher
rates of postoperative major adverse events [94,95] . While the etiology of the sex disparity in outcomes is likely
multifactorial, graft selection and strategies have been shown to differ between women and men, and may
play a role in this outcomes disparity . A retrospective study of 57,943 CABG patients (19% women)
[96]
[96]
found that incomplete revascularization, which was associated with lower survival in both sexes, was more
common in women (26% vs. 22%; P < 0.001). Women received fewer arterial grafts, were less likely to
receive total arterial revascularization, and more frequently received SVG-only revascularization in lieu of
any arterial grafting. A large retrospective study including more than one million CABG patients found that
women were less likely to receive LITA grafting to the LAD (adjusted OR 0.79, 95%CI: 0.75-0.83; P < 0.001),
[97]
the gold standard of CABG, than men . In addition, women were found to be less likely to receive MAG
than men (adjusted OR 0.78, 95%CI: 0.75-0.81; P < 0.001).

It is also unclear if women gain the same benefits from MAG as do men. In a retrospective cohort study of
the Ontario database including 9,135 women undergoing CABG , MAG was associated with a heightened
[98]
risk of 30-day mortality (HR 1.48, 95%CI: 1.23-1.79); however, there was improved survival at nine years in
women who received MAG (4.0% incremental improvement in survival over SAG). In a propensity-
matched study from the New York State Cardiac Surgery Reporting System from 2005-2014, Gaudino et al.
found that men who received MAG had a mortality benefit compared to men who received SAG (adjusted
HR 0.80, 95%CI: 0.73-0.87; P < 0.001), a similar benefit was not seen among women who received MAG
(adjusted HR 0.99, 95%CI: 0.84-1.15; P = 0.85) . Low-risk patients of both sexes who received MAG had a
[99]
lower risk of mortality and morbidity than those receiving SAG (men: adjusted HR 0.80, 95%CI: 0.73-0.89;
P < 0.001 and women: adjusted HR 0.80, 95%CI: 0.65-0.97; P = 0.02), but the high-risk patients of both sexes
did not (men: adjusted HR 0.95, 95%CI: 0.82-1.10; P = 0.47 and women: adjusted HR 1.14, 95%CI: 0.91-1.42;
P = 0.26). It is possible that the lack of any observed benefit with MAG in the overall cohort of women was
due to the relatively greater proportion of women who fell into the ‘high-risk’ category compared with men.
The ongoing ROMA:Women trial (NCT04124120), the first cardiac surgery trial in women, tests the MAG
hypothesis in women and will provide more data on the benefits of MAG in women [100,101] .