Objective To investigate the occurrence and influencing factors of adverse outcomes in elderly patients with coronary heart disease (CHD) and obstructive sleep apnea-hypopnea syndrome (OSAHS). Methods A multicenter prospective cohort trial was conducted on 265 elderly patients (≥60 years old) diagnosed with OSAHS and CHD through multiple-channel sleep monitoring during January 2015 and October 2017. Baseline demographic data, clinical features, sleep parameters, and blood biochemical indicators were collected, and all subjects were followed up until December 2020 for the occurrence of major adverse cardiovascular events (MACE). Patients were divided into MACE group (n=55) and non-MACE group (n=210) according to whether MACE occured. SPSS statistics 22.0 was used for data analysis. Student′s t test, Mann-Whitney U test or Chi-square test was employed for intergroup comparison depending on data type. Spearman correlation analysis and multivariate logistic regression analysis were employed respectively to analyze the correlation of MACE occurrence with above indicators and influencing factors for the occurrence in elderly patients with CHD and OSAHS. Results During a median follow-up time of 43 (5-72) months, the cumulative incidence of MACE was 20.8% (55/265). Compared with the non-MACE group, the MACE group had significantly larger proportions of smoking (41.8% vs 27.6%), atrial fibrillation (27.3% vs 14.3%), chronic obstructive pulmonary disease (92.0% vs 27.6%), higher level of platelet distribution width [PDW, (13.08±1.40)% vs (12.47±1.54)%], and obviously lower level of hemoglobin [(129.4±15.85) vs (135.24±16.87) g/L, all P<0.05)]. Spearman correlation analysis showed that the occurrence of MACE in elderly patients with CHD and OSAHS was positively correlated with age, smoking history, alcohol drinking history, PDW, total sleep time (TST), and atrial fibrillation (r=0.075,0.125,0.128,0.145,0.129,0.140; P<0.05), and negatively with hemoglobin level (r=-0.141; P<0.05). Multivariate logistic regression analysis indicated that PDW (OR=1.304,95%CI 1.046-1.627; P=0.018), TST (OR=1.274,95%CI 1.037-1.566; P=0.021), and hemoglobin level (OR=0.975,95%CI 0.954-0.996; P=0.022) were independent influencing factors for MACE in elderly patients with CHD and OSAHS.Conclusion The incidence of MACE is quite higher in elderly patients with CHD and OSAHS, and PDW and TST are independent risk factors for the occurrence, whereas hemoglobin is a protective factor.