Optical coherence tomography (OCT) improves outcomes during percutaneous coronary intervention (PCI), but standard imaging requires contrast injection to clear blood from the vessel lumen. This can be a concern in patients at risk of contrast-induced nephropathy. A prospective, multicenter observational analysis published in JACC Advances evaluated whether heparinized saline can be used as an alternative flushing agent during frequency-domain OCT imaging in PCI.

The analysis included 166 patients undergoing PCI at four tertiary centers in India. Each procedure incorporated paired OCT pullbacks using contrast and heparinized saline to allow within-patient comparison. A total of 2,072 matched OCT frame pairs from 259 runs were analyzed by two blinded investigators. Key vessel parameters evaluated included proximal reference diameter, minimal lumen area, minimum lumen diameter, and distal reference diameter (DRD). Ethical approvals were obtained, and all participants provided informed consent.

Vessel measurements were comparable between saline- and contrast-based OCT, with no statistically significant differences across parameters: proximal reference diameter (2.76±0.59 vs 2.74±0.60 mm; p=0.65), minimal lumen area (5.33±2.48 vs 5.36±2.52 mm²; p=0.85), minimum lumen diameter (2.55±0.68 vs 2.56±0.66 mm; p=0.78), and DRD (2.54±0.55 vs 2.55±0.55 mm; p=0.83). Bland–Altman analysis showed good agreement without proportional bias. Interobserver reliability was moderate to good, with intraclass correlation coefficients ranging from 0.69 to 0.79. Sensitivity analysis for clustering confirmed the robustness of the findings. No adverse events were reported with saline flushing.

Heparinized saline demonstrated comparable imaging performance to contrast in OCT-guided PCI. These findings indicate that heparinized saline is a feasible alternative flushing strategy for OCT-guided PCI, particularly when contrast minimization is desired.