Impact of operator volume on overall major adverse cardiac events following direct coronary stent implantation versus stenting after predilatation

OBJECTIVES: To determine the impact of operator experience on procedural, clinical and angiographic outcome after (direct) coronary stent implantation. BACKGROUND: Although for other forms of percutaneous coronary interventions an inverse relationship between operator volume and patient outcomes has been shown, the impact of operator volume on outcome after direct stenting has never been investigated. METHODS: A retrospective analysis was performed on data from a prospective randomized trial comparing direct stenting with that after predilatation. The trial consisted of 400 patients with stable and unstable angina pectoris and/or myocardial ischemia due to a coronary stenosis of a single native vessel eligible in 1999-2001 for direct stenting. For a single-center high-volume clinic (>1500 cases/year), the authors compared the most experienced operators (case load: >4000) with well trained practitioners (case load: 175). One hundred and fifteen patients were identified who were treated by high-volume and 180 who were treated by medium-volume operators. RESULTS: Baseline patient characteristics were evenly distributed among groups. High-volume, compared with medium-volume operators, were faster (30.8 versus 42.2 minutes, p < 0.001), needed less frequent postdilatation (15% versus 24%, p=0.06) and had lower fluoroscopy times (7.5 versus 11.2 minutes, p < 0.001), lower contrast usage (180 versus 228 ml, p < 0.001), lower procedural costs (€1982 versus €2164, p=0.05) and reduced rates of major adverse cardiac and cerebral event (MACCE) at six months (12.2 versus 21.1%, p=0.03). The medium-volume operator group experienced higher angiographic binary restenosis rates after direct stenting compared with stenting after predilatation (31.5 versus 14.9%, p=0.005). CONCLUSIONS: Stenting performed by high-volume operators resulted in a 50% reduction in MACCE as compared with medium-volume physicians, which also had twice as much restenosis when using direct stenting. Hence, the more demanding technique of direct stenting should not be performed by unsupervised operators who have not yet completed their training. Furthermore, prolonged training periods and even more intensive supervision by experienced operators seems mandatory.