Comment on “Sex-related differences in long-term mortality after coronary artery bypass graft surgery: a systematic review and meta-analysis”

Dear Editor,

We read with great interest the analysis by Zhang et al. [1], quantifying sex-related differences in long-term mortality after CABG.

Of particular concern is the temporal span of the included cohort, extending from 1972 to 2019, a 47-year window encompassing fundamentally different surgical eras. Internal thoracic artery grafting became the standard only in the late 1980s, and off-pump techniques, modern antiplatelet regimens, and contemporary perioperative care emerged decades after the earliest included studies [2]. Pooling a single odds ratio of 1.17 across this span implicitly treats the sex-mortality association as stable over five decades of evolving techniques and graft selection [3].

This matters because studies most representative of current practice, including Gaudino et al. (2021), Rubens et al. (2022), and Sattartabar et al. (2021), draw from larger, more recent cohorts than the earliest included studies, such as Rahimtoola et al. (1993) and Carey et al. (1995), which predate arterial grafting as routine care. A pooled estimate weighted by older surgical eras may not reflect the sex-mortality relationship that a contemporary surgeon should anticipate when counseling a patient today [4].

Stratifying the pooled estimate by surgical era or restricting the primary analysis to studies enrolling after arterial grafting became routine would clarify whether the disparity reflects a persistent biological signal or one narrowing with modern techniques [5]. This distinction carries direct weight for how the conclusions should inform present-day decision-making for women undergoing CABG.

Informed consent

Not applicable.

Ethical approval

Not applicable.

Data availability

No new data were generated or analyzed in this study.

Generative AI disclosure

Generative AI tools were used solely for language refinement and formatting assistance. All scientific interpretation, critical appraisal, and manuscript preparation were independently performed and verified by the authors.

Funding

None.

CRediT authorship contribution statement

Dilnoza Zaripova Yashinova: Conceptualization, Data curation, Formal analysis. Sanjar Yuldashev: Visualization, Writing – original draft, Writing – review & editing. Adkham Khodjaniyazov: Visualization, Writing – original draft, Writing – review & editing. Axmadjonova Gulnoza Murodovna: Visualization, Writing – original draft, Writing – review & editing.

Declaration of competing interest

The authors declare no conflicts of interest.