To achieve the stent optimization following "Keep It Simple and Safe" coronary intervention is recommended. A protocol of Joint Inflation with Nominal-pressure and Stability (JINS) approach in coronary drug-eluting stent (DES) implantation by intracoronary imaging (ICI) guidance could provide additional benefits in reducing unnecessary radiation exposure, and post-dilatation balloon angioplasty-related complications.

Variable types of stent inflation protocol to achieve evidence and consensus-based coronary drug-eluting stent (DES) optimization could improve clinical outcomes. The investigators aim to evaluate whether the JINS approach could be adopted in Chinese daily practice.

The investigators will perform ICI (OCT or IVUS)-guided DES implantation in coronary de novo lesions by JINS protocol, described as inflating stent balloon with nominal-pressure (+1~2atm) without decay for at least 30 seconds.

Inclusion Criteria:

• Patients with acute coronary syndrome (UA/NSTEMI/STEMI) plan to undergo OCT- or IVUS-guided DES implantation in de novo lesion.
• Patients provide written informed consent prior to enrollment.

Exclusion Criteria:

• Left main, ostial right coronary artery lesion.
• High thrombus burden at the index primary percutaneous coronary intervention.
• Active bleeding or bleeding diathesis, thrombocytopenia (platelet <100,000/mL), or hemoglobin <10 g/dL
• Hepatic dysfunction (serum liver enzyme>3 times the normal limit)
• Renal failure (eGFR <15 ml/min/1.73m2 or requiring dialysis)
• Life expectancy < 1 year