Index of Device Efficiency: IVUS-Based Metric to Quantify Cutting Balloon Performance in Calcified Coronary Lesions

Calcified coronary artery disease complicates percutaneous coronary intervention (PCI), yet no standardized parameter quantifies the efficiency of plaque-modifying devices.

To introduce and evaluate the Index of Device Efficiency (IDE), a novel intravascular ultrasound (IVUS)-derived metric quantifying the mechanical efficiency of cutting balloon (CB) angioplasty during the RODIN-CUT technique.

In this multicenter retrospective study, 50 heavily calcified lesions (47 patients) underwent 270 IVUS pullbacks. The IDE was defined as the ratio of maximal luminal diameter achieved to the nominal CB diameter ×100. Stepwise IDE dynamics were assessed after sequential high-pressure CB inflations. A plateau phase was defined as ≤ 0.3 mm further luminal diameter gain or ≤ 0.5 mm² area gain between inflations. The relationship between IDE ≥ 100% and post-stent expansion was evaluated. Safety outcomes were systematically recorded.

Mean age was 75 ± 8 years; 46% of lesions were in the left anterior descending artery and 30% in the left main bifurcation. Minimal lumen area increased from 4.0 ± 1.5 mm² at baseline to 5.8 ± 2.1 mm² after one inflation and to 8.8 ± 2.6 mm² after four inflations (p < 0.001). IDE ≥ 100% was reached in 40% of lesions after one inflation versus 92% after four, with no further gain thereafter (plateau). Lesions with IDE ≥ 100% more frequently achieved optimal stent expansion (82% vs. 10%, p = 0.007). No major procedural complications occurred.

IDE is a simple, reproducible IVUS-derived metric that quantifies CB efficiency, identifies a reproducible plateau after four inflations, and predicts optimal stent expansion.