Statins have been shown to prevent microvascular dysfunction that may cause periprocedural myocardial infarction after percutaneous coronary intervention (PCI). Evolocumab has more potent lipid-lowering properties than statins. Aims: The aims of this study were to investigate whether evolocumab pretreatment on top of statin therapy could prevent periprocedural microvascular dysfunction. Methods: This study included 100 patients with stable coronary artery disease who were scheduled to undergo PCI and had high low-density lipoprotein cholesterol (LDL-C) under statin therapy. Patients were randomised to receive evolocumab 140 mg every 2 weeks for 2 to 6 weeks before PCI (evolocumab group: N=54) or not (control group: N=46). The primary endpoint was the index of microvascular resistance (IMR) after PCI. Troponin T was measured before and 24 hours after PCI. Results: Geometric mean LDL-C was 94.1 (95% confidence interval [CI]: 86.8-102.1) mg/dl and 89.4 (95% CI: 83.5-95.7) mg/dl at baseline, and 25.6 (95% CI: 21.9-30.0) mg/dl and 79.8 (95% CI: 73.9-86.3) mg/dl before PCI, in the evolocumab group and in the control group, respectively. PCI was performed 22.1±8.5 days after allocation. Geometric mean IMR was 20.6 (95% CI: 17.2-24.6) in the evolocumab group and 20.6 (95% CI: 17.0-25.0) in the control group (p=0.98). There was no significant difference in the geometric mean of post-PCI troponin T (0.054, 95% CI: 0.041-0.071 ng/ml vs 0.054, 95% CI: 0.038-0.077 ng/ml; p=0.99) and in the incidence of major periprocedural myocardial infarction between the 2 groups (44.4% vs 44.2%; p=1.00). Conclusions: Evolocumab pretreatment did not prevent periprocedural microvascular dysfunction in patients on modern medical management with statins.