Imaging Comparisons Between Bifurcation Stenting Procedures Performed in Human Patients and Those Within Reanimated Swine Hearts

Background: Reanimated swine hearts have been used for over a decade to study bifurcation percutaneous coronary intervention, on the assumption that their results resemble those in patients, which has rarely been tested directly. Objectives: The objective of the study was to test how closely provisional bifurcation procedures performed in reanimated swine hearts agree with the human stent-geometry result of a given technique. Methods: We pooled individual-case data from 2 randomized (1:1) trials sharing 1 protocol, comparing proximal optimization technique (POT)/kissing/POT and POT/side/POT (PSP) in 30 percutaneous coronary interventions in 17 reanimated swine hearts and 60 patients. Stent geometry was assessed across ten endpoints in 4 subsegments by human-optical coherence tomography (OCT), swine-OCT, and micro-computed tomography (CT) of the explanted swine stents. Results: Swine-OCT agreed with micro-CT at the distal main vessel (concordance correlation coefficient 0.83). The technique effect agreed in direction at 8 of 10 endpoints; the descriptive calibration slope was 1.04 (indistinguishable from unity), although the case-level bootstrap was imprecise (slope 0.88; 95% CI: 0.47-1.54). Distal main-vessel expansion was lowest with PSP (mean 91% vs 98% in swine; 84% vs 99% in patients); major malappositions were rare after POT/kissing/POT but affected about half of PSP cases in both species. OCT matched micro-CT for expansion but not eccentricity; underexpansions extended farther along the larger human vessel. Conclusions: A reanimated swine-heart model showed close concordance with the human geometric result of bifurcation techniques, matching the direction at 8 of 10 endpoints and, approximately, the magnitude. This is descriptive concordance, not proven predictive equivalence, and supports the model as a preclinical screening tool pending prospective validation.