We read with great interest the study by Skorupski et al. [1] evaluating intravascular lithotripsy (IVL) in calcified left main (LM) coronary artery disease and reporting 2-year clinical outcomes. The authors should be commended for providing valuable real-world data in a particularly complex and high-risk anatomical subset. Nevertheless, we believe that several methodological aspects deserve further clarification and discussion.

Although the manuscript emphasizes long-term outcomes of IVL in LM disease, the analytical framework is primarily based on a comparison between LM-IVL and non-LM-IVL patients, leading to the conclusion that long-term clinical outcomes were comparable. In our view, LM and non-LM interventions represent fundamentally different procedural entities rather than equivalent comparators. LM PCI is inherently high risk, frequently involving bifurcation strategies, larger guiding catheters, more complex stenting techniques, and, in selected cases, mechanical circulatory support. Indeed, in the present study, ≥ 7F guiding catheters and mechanical support were used substantially more often in the LM group. In contrast, non-LM interventions generally involve smaller-caliber vessels supplying a more limited myocardial territory. Therefore, directly comparing long-term outcomes between LM and non-LM IVL procedures may resemble a comparison between intrinsically different procedural and prognostic scenarios. This raises a conceptual issue: if the primary objective is to assess the long-term safety and efficacy of IVL in LM disease, a focused evaluation of the LM cohort, interpreted within the context of contemporary LM PCI literature, might provide a clearer message. Conversely, juxtaposing LM and non-LM outcomes may inadvertently imply procedural equivalence where none inherently exists.

Moreover, the 2-year all-cause mortality was numerically higher in the LM group (14.8%) compared with the non-LM group (6.3%), although the difference did not reach statistical significance (p = 0.087). The absence of statistical significance should not be equated with equivalence, particularly in the setting of limited sample size and event numbers. As the study was not designed as a non-inferiority or equivalence trial, describing the outcomes as “comparable” warrants cautious interpretation.

Finally, the distribution of IVL balloon diameters in the LM cohort deserves attention. Most LM cases were treated with 3.5 mm balloons, while 4.0 mm balloons were used less frequently. Considering that the reference diameter of the adult LM artery is often in the range of 4.0–5.0 mm, relatively small balloon sizing may have influenced the degree of calcium modification and the final minimal stent area achieved.

In conclusion, this study adds important real-world insight into IVL use in LM disease. However, given the intrinsic differences between LM and non-LM procedures, direct comparison of their long-term outcomes should be interpreted with caution. A dedicated analysis centered exclusively on the LM cohort may more closely align with the stated objective and strengthen the overall message.

Funding

No external funding.

Ethical approval

Not applicable.

Conflict of interest

The authors declare no conflict of interest.