High-speed rotational atherectomy versus modified balloons prior to drug-eluting stent implantation in severely calcified coronary lesions: The randomized prepare-CALC trial

Abstract

BACKGROUND: Balloon dilatation or debulking seems to be essential to allow successful stent implantation in calcified coronary lesions. Compared with standard balloon predilatation, debulking using high-speed rotational atherectomy (RA) is associated with higher initial procedural success albeit with higher in-stent late lumen loss at intermediate-term follow-up. Whether modified (scoring or cutting) balloons (MB) could achieve similar procedural success compared with RA is not known. In addition, whether new-generation drug-eluting stents could counterbalance the excessive neointimal proliferation triggered by RA remains to be determined. METHODS AND RESULTS: We randomly assigned patients with documented myocardial ischemia and severely calcified native coronary lesions undergoing percutaneous coronary intervention to a strategy of lesion preparation using MB or RA followed by drug-eluting stent implantation. Stenting was performed using a third-generation sirolimus-eluting stent with a bioabsorbable polymer. The trial had 2 primary end points: strategy success (defined as successful stent delivery and expansion with attainment of <20% in-stent residual stenosis in the presence of TIMI [Thrombolysis in Myocardial Infarction] 3 flow without crossover or stent failure; powered for superiority) and in-stent late lumen loss at 9 months (powered for noninferiority). Two hundred patients were enrolled at 2 centers in Germany (n=100 in each treatment group). The mean age of the study population was 74.9±7.0 years; 76% were men, and 33.5% had diabetes mellitus. Strategy success was significantly more common in the RA group (81% versus 98%; relative risk of failure with an MB- versus RA-based strategy, 9.5; 95% CI, 2.3-39.7; P=0.0001), but mean fluoroscopy time was longer (19.6±13.4 versus 23.9±12.2 minutes; P=0.03). At 9 months, mean in-stent late lumen loss was 0.16±0.39 mm in the MB group and 0.22±0.40 mm in the RA group (P=0.21, P=0.02 for noninferiority). Target lesion revascularization (7% versus 2%; P=0.17), definite or probable stent thrombosis (0% versus 0%; P=1.00), and target vessel failure (8% versus 6%; P=0.78) were low and not significantly different between the MB and RA groups. CONCLUSIONS: Lesion preparation with upfront RA before drug-eluting stent implantation is feasible in nearly all patients with severely calcified coronary lesions, is more commonly successful as a primary strategy compared with MB, and is not associated with excessive late lumen loss. A strategy of provisional MB remains feasible, safe, and effective as long as bailout RA is readily available and may offer the advantages of compatibility with smaller sized catheters and less irradiation. Both strategies are associated with excellent clinical outcome at 9 months. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02502851.