DCB vs DES for Severe Coronary Calcification After Optimal Modification Assessed by QFR

The goal of this clinical trial is to learn if the short and long term effect of drug coated balloon (DCB) is non-inferior to drug eluting stent (DES) in patients with severe coronary calcification after optimal calcium modification assessed by quantitative flow ratio (QFR). The main questions it aims to answer are: 1. Researchers will compare to see if DCB is non-inferior to DES when evaluated by major cardiovascular adverse events (MACE) one year after percutaneous coronary intervention (PCI). 2. Researchers will compare to see if the perioperative cardiovascular events is different between DCB and DES treated lesions. 3. Researchers will compare to see if the QFR is different between DCB and DES treated lesions one year after PCI. Participants with severe coronary calcification diagnosed by coronary angiography or intravascular ultrasound (IVUS) will receive calcium modification through rotational atherectomy (RA), excimer laser coronary angioplasty (ELCA), or intravascular lithotripsy (IVL). Then, QFR will be measured based on angiographic image. QFR \>0.8 will be defined as optimal calcium modification and patients will be randomized 1:1 to DCB or DES treated groups. Telephone follow-ups will be conducted at 1 month, 6 months after PCI and .angiophraphy follow-up will be performed at 12 months after PCI.

Perioperative cardiovascular events include side branch loss, coronary perforation, no-reflow/slow flow, and perioperative myocardial infarction defined as an elevation of cardiac markers (cTN or CK-MB) greater than 5 times the upper limit of normal. Definite or probable thrombosis in DCB or DES treated vessels will be documented. After randomization, if a dissection with restricted blood flow occurs after DCB treatment, DES will be implanted.