Rethinking Bifurcation PCI: A Conceptual Rationale for a Planned Side Branch–First Drug‐Coated Balloon Strategy

A recent meta-analysis by Rocchetti et al., published in Catheterization and Cardiovascular Interventions, demonstrated that the use of drug-coated balloons (DCBs) for the side branch (SB) following main vessel (MV) stenting in coronary bifurcation interventions is associated with a significant reduction in major adverse cardiovascular events and myocardial infarction [1]. These findings reinforce the pharmacological value of minimizing metal burden across the SB ostium and highlight the progressive maturation of hybrid bifurcation strategies. However, the majority of evidence supporting the use of SB DCB has been derived from provisional strategies based on an MV-first approach. While these studies clearly demonstrate that DCB application after MV stenting can provide meaningful pharmacological and mechanical benefits, this evidence base does not sufficiently represent a different anatomical scenario, namely true bifurcation lesions in which both the MV and SB are considered treatment targets from the outset and where a two-stent strategy is frequently contemplated. In this context, an alternative sequencing concept planned SB treatment with a DCB prior to any stent implantation merits conceptual discussion. In selected true bifurcation anatomies, the assumption that the procedure must invariably begin with MV stenting may be open to reconsideration. A planned SB-first DCB sequencing strategy may represent a rational alternative, in which SB treatment with a DCB is performed prior to MV drug-eluting stent (DES) implantation, while preserving the option for bail-out SB stenting if required. This strategy may serve as an anatomy-adapted intermediate pathway between up-front two-stent techniques and delayed provisional SB intervention in bifurcations where both branches are initially deemed clinically relevant. The potential value of such a sequencing strategy can be supported by several complementary mechanical and biological considerations. DCB application to the SB before MV stenting allows direct and homogeneous contact between the balloon and the vessel wall, facilitating more efficient drug transfer to the ostial segment. This enables targeted drug delivery without interference from MV stent struts. SB intervention after MV stenting requires re-crossing through distal stent cells and advancing a DCB across metallic struts, thereby increasing procedural complexity. This step is associated with potential drug loss due to balloon–strut friction, longitudinal mechanical stress on the stent, and operator-dependent variability. Treating the SB before DES implantation eliminates these technical challenges upfront and allows for a more controlled and predictable procedural workflow. Re-crossing a newly implanted MV DES to treat the SB may predispose to malapposition, elliptical deformation, and cumulative metal fatigue. Performing SB DCB treatment prior to DES implantation preserves MV stent geometry by avoiding subsequent cross-strut manipulation. While a planned SB-first DCB approach may offer procedural and mechanical advantages, some theoretical limitations should be considered. If MV stenting leads to plaque or carina shift requiring further SB ballooning, additional manipulation could potentially reduce or displace part of the drug previously delivered to the SB surface. However, in the DCB-BIF study, protocols that included kissing balloon inflation after DCB treatment were not associated with any signal of adverse clinical impact. This observation suggests that the clinical effectiveness of DCB therapy may still be maintained despite subsequent ballooning [2]. Taken together, these considerations suggest that a planned SB-first DCB strategy may shorten procedural steps, reduce re-crossing maneuvers, minimize mechanical stress on implanted metallic scaffolds, and avoid unnecessary dual-metal layers, while still maintaining the option for bail-out SB stenting when clinically indicated. To date, no randomized trial has directly evaluated a planned SB-first DCB followed by MV DES strategy. However, the combination of biological plausibility and procedural coherence supports conceptual consideration of this approach in carefully selected bifurcation anatomies where the SB is considered a treatment target from the outset. In conclusion, this discussion may extend beyond whether the SB can be rescued, toward whether the procedural sequence itself could be reconsidered in selected coronary bifurcation anatomies from both clinical and mechanistic perspectives. The author declares no conflicts of interest.