Higher Risk of Heart Events in Older Cancer Survivors Linked to Chemotherapy

Older cancer survivors face a significantly higher risk of cardiovascular events, including stroke, heart attack, and heart failure, a study finds.¹

Cancer survivors had more than double the rate of CVD events, including stroke, heart attack, and heart failure hospitalizations. | Image credit: tashatuvango - stock.adobe.com

The secondary analysis of a randomized, double-blind, placebo-controlled, multi-institution clinical trial is published in Cancer.²

“Our research contributes to the growing body of work indicating that cancer- and treatment-related cardiovascular disease is a very real risk in cancer survivors,” said Suzanne Orchard, PhD, Monash University, lead researcher of the study.¹ “Cardiovascular disease can have a significant impact on both quality of life and survival for patients with cancer. Fortunately, with early screening and preventative measures, some of the cancer-related risks can be mitigated.”

The study collected clinical data on cancer diagnoses and cardiovascular events through medical records, participant reports, and hospital admission data. Additionally, the study utilized data from the Aspirin in Reducing Events in the Elderly (ASPREE) trial, which included participants aged 70 years and older from Australia and the United States. The researchers analyzed data from 15,454 elderly participants, of which 1392 developed cancer during the study period. The participants were followed for an average of 4.6 years.

The primary outcomes were cardiovascular disease (CVD) events, including stroke, heart attack, and hospital admissions for heart failure. These events were tracked and compared between participants who developed cancer and those who remained cancer-free.

The researchers calculated the rate of cardiovascular events, expressed as events per 1000 person-years, and compared rates between cancer survivors and cancer-free individuals. They also adjusted for traditional cardiovascular risk factors to ensure that the observed effects were attributable to cancer and its treatments.

A subgroup analysis examined the impact of different cancer types, including metastatic, blood, and lung cancers, and specific treatments on cardiovascular outcomes. Treatments other than chemotherapy, including hormonal therapy, targeted therapy, immunotherapy, and radiation therapy, were also analyzed, though their results were inconclusive.

As the ASPREE trial involved aspirin as a clinical intervention, the researchers also explored whether aspirin affected cardiovascular event rates, but no significant impact was observed.

Cancer survivors had more than double the rate of CVD disease events, including stroke, heart attack, and heart failure hospitalizations, compared with participants who did not develop cancer. The rate of cardiovascular events was 20.8 per 1000 person-years in cancer survivors, compared with 10.3 events per 1000 person-years in cancer-free participants. The highest incidence of cardiovascular events was observed in patients with metastatic cancer, blood cancers, and lung cancers, suggesting that certain cancer types may confer a greater cardiovascular risk.

Chemotherapy was associated with a 2-times higher risk of cardiovascular events. This finding emphasizes chemotherapy’s significant contribution to long-term cardiovascular damage in cancer survivors. The increased cardiovascular risk in cancer survivors persisted even after accounting for traditional cardiovascular disease risk factors, including high blood pressure and diabetes, highlighting that cancer and its treatments independently contribute to this heightened risk.

"Our analysis suggested an increased risk of CVD following chemotherapy and decreased risk in those who had had surgery," wrote the researchers of the study.² "The risk of CVD was greatest soon after an incident cancer diagnosis and remained elevated relative to the total cohort and cancer‐free risk‐ set across the 4‐year follow‐up period."

References

1. Do cancer and cancer-related treatments increase cardiovascular disease risk in older cancer survivors? News release. Cancer News Alert. September 23, 2024. Accessed September 20, 2024.

2. Muhandiramge J, Zalcberg JR, Warner ET, et al. Cardiovascular disease and stroke following cancer and cancer treatment in older adults. Cancer. September 23, 2024. Accessed September 2024. https://onlinelibrary.wiley.com/doi/abs/10.1002/cncr.35503