An analysis of the virtual cardio-oncology research initiative (VICORI) resource: bleeding risk among cancer patients beyond 1-year post-myocardial infarction
Authors: Ow K W , Tyrer F , Van Den Berg P F , Lai J , Vernon S , Paley L , Rutherford M , Lambert P , De Belder M , Deanfield J , Peake M , Adlam D 
Published: October 2024

Abstract

Introduction
Cardiovascular disease (CVD) and cancer are common causes of morbidity and mortality. Advancements in treatment strategies for both diseases have resulted in a growing population who live with both conditions. Myocardial infarction (MI) represents approximately 20% of all CVD admissions in cancer patients and 10% of patients who present with an acute MI have cancer. Managing MI patients with cancer require careful balancing of their ischaemic and bleeding risks. While dual antiplatelet therapy (DAPT) increases a patient’s bleeding risk, cancer patients are at further increased risk due to a range of direct and indirect cancer effects. While our recent studies demonstrated an increased bleeding risk in cancer patients in the 1st year after MI (the period of intensive APT), it is currently not known if this risk is sustained beyond this period. VICORI is the world’s first whole-country cardio-oncology research platform, linking data from the National Cancer Registration and Analysis Service, National Institute for Cardiovascular Outcomes Research and Hospital Episode Statistics [1]. We investigated the risk of bleeding among MI patients in the 2nd year post-MI, where a large majority of patients would have completed a course of DAPT, stratified by the presence or absence of cancer.

Methods
In this retrospective observational study, we investigated the risk of bleeding following an MI between 2006-2019, in patients with and without cancer. Cancer was defined as a diagnosis of cancer in the 1-year preceding MI. Patients who lived past the 1st year after MI were followed-up from 12 to 24 months after their MI. We used inverse probability weighting based on propensity scores to produce a balanced cohort of patients with and without cancer. Cox proportional hazard and flexible parametric modelling were used to investigate cancer as a predictor of bleeding. Subgroup analyses were performed on stent status, MI and cancer type.

Results
Of 506280 patients presenting with MI, 5666 (1.1%) had cancer while 500614 (98.9%) did not. Prostate (n=1377), colorectal (n=1024), lung (n=490), breast (n=448) and bladder (n=334) cancers were among the most common types of cancers. The rate (hazard) of bleeding in MI was higher in patients with cancer in the 2nd year post-MI (HR:1.42, 95%CI 1.29-1.56) compared to those without. From the flexible parametric survival analysis, the risk of bleeding in cancer patients in the 2nd year post-MI was lower compared to the 1st year but remained statistically significant compared to non-cancer patients.

Conclusion
In this large real-world study, cancer patients have a persistent, increased bleeding risk beyond the 1-year post-MI period, compared to those without cancer, and this risk differed by type of cancer. Further work is needed to identify specific patient characteristics in each patient sub-group which alters one’s ischaemic or bleeding risk so they can be balanced favourably with personalised strategies.