Multicentre Cohort Study of the Impact of Percutaneous Coronary Intervention on Patients With Concurrent Cancer and Ischaemic Heart Disease

BACKGROUND The incidence of concurrent cancer and ischaemic heart disease (IHD) is increasing; however, the long-term patient prognoses remain unclear. METHODS Five-year all-cause mortality data pertaining to patients in the Osaka Cancer Registry, who were diagnosed with colorectal, lung, prostate, and gastric cancers between 2010 and 2015, were retrieved and analysed together with linked patient administrative data. Patient characteristics (cancer type, stage, and treatment; coronary risk factors; medications; and time from cancer diagnosis to index admission for percutaneous coronary intervention [PCI] or IHD diagnosis) were adjusted for propensity score matching. Three groups were identified: patients who underwent PCI within 3 years of cancer diagnosis (n = 564, PCI + group), patients diagnosed with IHD within 3 years of cancer diagnosis who did not undergo PCI (n = 3058, PCI-/IHD + group), and patients without IHD (n = 27,392, PCI-/IHD- group). Kaplan-Meier analysis was used for comparisons. RESULTS After propensity score matching, the PCI + group had better prognosis (n = 489 in both groups, hazard ratio 0.64, 95% confidence interval 0.51-0.81, P < 0.001) than the PCI-/IHD + group. PCI + patients (n = 282) had significantly higher mortality than those without IHD (n = 280 in each group, hazard ratio 2.88, 95% confidence interval 1.90-4.38, P < 0.001). CONCLUSIONS PCI might improve the long-term prognosis in cancer patients with IHD. However, these patients could have significantly worse long-term prognosis than cancer patients without IHD. Since the present study has some limitations, further research will be needed on this important topic in cardio-oncology.