Safety and Feasibility of Orbital Atherectomy via Transradial Approach in Severe Coronary Artery Calcification.

Background
Severe coronary artery calcification is associated with worse clinical outcomes following percutaneous coronary intervention (PCI). Atherectomy strategies have been used to improve procedural success, facilitate stent delivery and maximal expansion and improve long term outcomes. We compared outcomes between transfemoral (TF) and transradial (TR) approach for orbital atherectomy (OA) with adjunctive PCI.

Methods
A retrospective review between November 1, 2015 and May 31, 2017 of clinical variables for 91 consecutive patients undergoing OA with PCI (51 TF and 40 TR) was performed. This represented 6% (91/1505) of all PCIs performed during that period. Baseline patient characteristics, procedural variables and 30-day serious adverse event rates (vascular/bleeding complication and major adverse cardiac events) were compared. Independent t-test and Fisher’s exact test were performed and p-values of <0.05 were accepted as statistically significant.

Results
There was no significant difference in number of lesions treated (TF 1.67 +/- 0.7 vs TR 1.83 +/- 0.68, p = 0.28) or atherectomy vessel stents placed (TF 1.72+/- 0.77 vs TR 1.93 +/- 0.69, p = 0.18) between groups. There were significantly more total stents (atherectomy plus non atherectomy vessel) placed in the TR group (TF 2 +/- 0.9 vs TR 3.1 +/- 1.14; p = 0.038). Fluoroscopy time was longer in the TR group (TF 23.78 +/- 9.74 vs TR 28.9 +/- 12.8 min, p = 0.033) and contrast volume was higher in TR group (TF 200.27 +/- 75.1 vs TR 238.07 +/- 80.96 mL, p = 0.024). All cases achieved technical success with no crossover from TR to TF. At 30 days, there were significantly more serious adverse events seen in the TF group (TF 7/51 vs 0/40 events, p = 0.017).

Conclusions
OA is feasible with a high procedural success rate and an overall low complication rate regardless of approach. TR approach was associated with longer fluoroscopy time and higher contrast volume compared to TF. In the TR group, however, more stents were placed and a greater number of vessels were treated. At 30 days, the TR group had experienced significantly fewer serious adverse events. TR OA is a safe and effective alternative to standard TF approach for treating complex, calcified coronary lesions.