Cancer-specific mortality after acute coronary syndrome: insights from a nationwide real-world cohort

Background Long-term prognosis after Acute Coronary Syndrome (ACS) is increasingly influenced by non-cardiovascular deaths, with cancer emerging as the leading contributor. Nevertheless, comprehensive real-world evidence on cancer-specific mortality across ACS subtypes and their temporal trajectories remains limited. Purpose To investigate the spectrum of cancer-related mortality after ACS and to compare temporal cancer mortality risks between Acute Myocardial Infarction (AMI) and Unstable Angina (UA). Methods In this nationwide, multicentre, individual-based cohort study, ACS patients discharged from the Chinese Cardiovascular Association database - Chest Pain Centers (2018–2021) were initially involved. Outcome data were obtained by linking their national identification numbers to the Chinese CDC - Cause of Death Reporting System. In-hospital deaths and cases with missing discharge data were excluded. Causes of death were categorised according to ICD-10 codes. Competing risks analysis was used to compare cancer mortality between AMI and UA by employing the Fine-Gray model, with cardiovascular death treated as a competing event. Temporal patterns were assessed in two phases: within 12 months and beyond 12 months post-discharge. Results Among 1,562,956 ACS patients (mean age 63.8±12.3 years; AMI: 60.95%, UA: 39.05%), 11,172 cancer deaths (72.2% male) occurred over 4 years. Lung cancer accounted for 34.7% of cases, followed by gastric (12.6%), liver (12.4%), oesophageal (5.6%), and pancreatic cancers (4.1%). Lung cancer was the leading cause across ACS subtypes (Table 1). After multivariable adjustment, UA patients had a lower survival probability compared with AMI patients (adjusted sHR 1.44, 95% CI 1.39–1.50, p<0.01) (Figure 1A and B). Within the first year post-discharge, cancer-specific mortality risk was similar across ACS subtypes; however, a significantly elevated risk was observed in UA patients beyond 12 months (HR 1.14, 95% CI 1.08–1.19, p<0.05) (Figure 1C). Conclusion Among Chinese ACS-discharged patients, lung cancer was the predominant cause of cancer mortality. Patients presenting with UA exhibited a significantly elevated long-term cancer mortality burden compared to those with AMI. These findings highlight the importance of long-term cancer risk monitoring after ACS, in particular for the follow-up care of UA patients.