BACKGROUND: In patients with acute coronary syndromes (ACS) requiring percutaneous coronary intervention (PCI), abnormally elevated platelet counts are often associated with an increased risk of stent thrombosis and bleeding. AIMS: To explore the associations between clinical benefits and PCI in patients with ACS and elevated platelet counts. METHODS: Between July 2017 and December 2019, 50,009 patients with ACS were enrolled in the Improving Care for Cardiovascular Disease in China-Acute Coronary Syndrome Project. This study included patients with platelet count≥300×10 RESULTS: Among 4501 patients, PCI rates decreased as platelet count increased, with 3029 patients ultimately undergoing PCI. These patients exhibited a lower rate of NACE (adjusted odds ratio [OR]: 0.53, 95% confidence interval [95% CI]: 0.37-0.77
P=0.001) and a reduced risk of MACCE (OR: 0.44, 95% CI: 0.29-0.67
P<
0.001). No significant differences in major bleeding were observed (adjusted OR: 1.40, 95% CI: 0.62-3.16
P=0.417). Inverse probability of treatment weighting confirmed these findings. CONCLUSION: In patients with ACS and increased platelet counts who have more complex thrombohaemorrhagic profiles, PCI can effectively reduce the risk of ischaemic events without increasing the risk of bleeding. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/study/NCT02306616.