# Investigations of injection strategies to use heparinized normal saline instead of contrast media for intracoronary optical coherence tomography imaging

## TL;DR

This study shows that using heparinized saline instead of contrast media for OCT imaging during heart procedures can produce high-quality images suitable for clinical use.

## Contribution

The study demonstrates a novel injection strategy using heparinized saline as an alternative to contrast media for OCT imaging.

## Key findings

- 91.5% of OCT imaging runs were clinically suitable for use with heparinized saline.
- Heparinized saline injections produced high-quality OCT images comparable to standard methods.
- The technique is safe and effective for patients at risk of contrast-induced kidney injury.

## Abstract

The benefits of intravascular imaging-guided percutaneous coronary interventions (PCI) are well established. Intravascular imaging guidance improves short- and long-term outcomes, especially in complex PCI. Optical coherence tomography (OCT) has a higher resolution than intravascular ultrasound. However, the usage of OCT is mainly limited by the need to use contrast for flushing injections, which increases the risk of contrast-induced acute kidney injury, especially in patients with underlying chronic kidney disease. The aim of this study was to prove that flushing techniques with normal saline instead of contrast can be used in OCT imaging and can generate high-quality images.

This prospective single-center observational study included patients with indications for OCT-guided PCI. For OCT pullbacks, heparinized saline was injected by an automatic pump injector at different rates, and additional extension catheters for selective coronary artery engagement were used at the operator’s discretion. Recordings were made using the Ilumien Optis OCT system (Abbott) and the Dragonfly (Abbott) catheter and were analyzed at 1-mm intervals by two operators. Pullbacks were categorized as having optimal, acceptable, or unacceptable imaging quality. A clinically usable run was determined if >75% of the region of interest length was described as having optimal or acceptable imaging quality.

A total of 32 patients were enrolled in the study; 47 different lesions were assessed before and after PCI. In total, 91.5% of runs were described as clinically suitable for use.

Heparinized saline injections for OCT imaging are effective in generating good-quality OCT images suitable for clinical use.