Impact of Calcium Fracture After Balloon Angioplasty in Patients With Complex Calcified Coronary Plaque ~The Results of the OCT‐CALC Registry~

Background Target lesion calcification is known to influence the percutaneous coronary intervention (PCI) outcomes. This study aimed to assess the impact of calcium fractures after balloon angioplasty on the PCI results as well as the long‐term clinical outcomes. Methods We formed a prospective, multicenter registry that enrolled 268 patients who underwent PCI to lesions with moderate to severe calcification. Balloon dilatation and subsequent drug eluting stent implantation were performed with optical coherence tomography (OCT) guidance in every case. Serial OCT images just before and after balloon angioplasty, and after stent implantation were analyzed at 1‐mm intervals by an independent core laboratory. The primary endpoint was the relationship between calcium fracture after balloon angioplasty and stent expansion. The secondary endpoint was target vessel failure (TVF) at 1 year, defined as a composite of cardiac death, target vessel‐related myocardial infarction, and target vessel revascularization. Results A total of 242 patients were analyzed. Of these, OCT analysis was performed in 147 patients with a complete OCT data set. Calcium fractures were observed in 28 patients (19%) at the minimal lumen area site. The percent stent expansion was greater in lesions with calcium fracture than those without (99 ± 26% vs. 91 ± 18%, p = 0.039). In 229 patients who underwent clinical follow‐up at 1 year, TVF occurred in 23 patients (10.0%). Conclusion The OCT‐guided PCI strategy demonstrated acceptable acute and 1‐year clinical outcomes. The presence of calcium fractures after balloon angioplasty may have a potential impact on acute results after DES implantation in calcified lesions.