Diagnostic Performance of a Dual Sensor System in Assessment of Coronary Calcification: An Ex Vivo Cadaveric Study

BACKGROUND: Accurate assessment of coronary calcification informs procedural planning in percutaneous coronary intervention (PCI), yet neither optical frequency domain imaging (OFDI) nor intravascular ultrasound (IVUS) alone provides comprehensive diagnostic information. The dual sensor system (DSS) was developed to integrate and complement both imaging modalities. AIMS: To determine the diagnostic value of DSS for detecting and characterizing calcification compared with either modality alone. METHODS: Twenty coronary arteries from 17 cadaver hearts underwent DSS pullbacks. Eighty-seven histological sections and their co-registered DSS images were analyzed, with histology serving as the reference standard. Four cardiologists blinded to histology independently assessed calcification using OFDI alone, IVUS alone, and DSS. OFDI signal attenuation and IVUS reverberation artifacts were examined as potential indicators of maximum calcification thickness. RESULTS: DSS demonstrated the highest sensitivity (DSS 98.0%; OFDI 85.5%, p < 0.001; IVUS 94.4%, p = 0.019) and accuracy (DSS, 97.7%; OFDI, 86.5%, p < 0.001; IVUS, 92.8%, p = 0.004) for detecting calcification. Inter-observer agreement was also highest in DSS (κ: DSS, 0.82; OFDI, 0.53; IVUS, 0.53). In subgroup analysis, sensitivity was significantly higher in DSS for sections with calcification arc < 180° (DSS, 98.6%; OFDI, 83.8%; IVUS, 94.0%), but not for those with ≥ 180°. Maximum calcification thickness was greater in calcifications only with OFDI attenuation than in those without (1423.8 [988.8-1994.1] vs. 686.4 [552.8-906.3] µm, p < 0.001). CONCLUSIONS: DSS provides accurate and consistent detection of coronary calcification and may help stratify calcification by thickness. Future studies should assess whether these advantages translate into clinical benefits.