Prognosis following acute coronary syndrome according to cancer type and status – a nationwide Danish cohort study
Authors: Nouhravesh N , Strange J , Toennesen J , Holt A , Andersen C F , Jensen M H , Al-Alak A , D'Souza M , Nielsen D , Kragholm K H , Fosboel E L , Schou M , Lamberts M K 
Published: October 2022

Abstract

Background
Survival of patients with cardiovascular disease and cancers has increased due to improved treatments. However, the prognosis of acute coronary syndrome (ACS) in cancer patients is widely unknown, challenging clinical decision-making.

Purpose
To investigate prognosis and selected treatment strategy for the most prevalent cancers (breast, gastrointestinal and lung cancer), according to cancer status, following first-time ACS.

Methods
Using Danish, nationwide registers, we identified patients with ACS from 2000 through 2018. Patients were stratified according to cancer status as either “no cancer”, “history of cancer” (no hospital contact for cancer within five years), “non-active cancer” (curative intended treatment, with hospital contacts within five years) and “active cancer”. Follow-up began at the date of ACS admission. The primary outcome was 1-year absolute risk (AR) of all-cause mortality and cardiovascular- or non-cardiovascular mortality. The secondary outcome was a 30-day cumulative incidence of undergoing coronary angiogram (CAG). Cumulative incidences and AR were estimated non-parametrically with the Aalen-Johansen non-parametric method, accounting for competing risk of death when relevant. A 95% confidence interval (CI) was reported for these estimates.

Results
We identified a total of 157,264 patients with ACS; 150,478 (95.7%) had no cancer, 2,370 (1.5%) were identified with history of cancer, 2,712 (1.7%) with non-active cancer and 1,704 (1.1%) with active cancer. Patients with cancer were older with more comorbidities than patients with no cancer. One-year AR of all-cause mortality for active cancers compared with no cancer was 44% (95% CI: 38.2–49.4) for breast cancer, 58% (95% CI: 54.2–61.8) for gastrointestinal cancers and 73% (95% CI: 70.3–76.7) for lung cancer, compared with 18% (95% CI: 17.3–17.6) for no cancer (Figure 1). Cardiovascular disease was the leading cause of death in all patients as seen in Figure 2. For patients with non-active cancer, the cumulative incidence of having a CAG performed was 61% (95% CI: 56.9–65.7) for breast cancer, 57% (95% CI: 53.7–60.7) for gastrointestinal cancers and 59% (95% CI: 51.3 to 65.6) for lung cancer, compared to 77% (95% CI: 76.7–77.4) for no cancer. For patients with active cancer, the cumulative incidence dropped to 43% (95% CI: 35.7–50.9), 43% (95% CI: 37.0–48.3) and 31% (95% CI: 27.1–35.3) for respectively breast-, gastrointestinal and lung cancer.

Conclusion
The 1-year AR of all-cause mortality of cancer patients increased incrementally (no cancer &lt; history of cancer &lt; non-active cancer &lt; active cancer) for all cancer types, with breast cancer having the lowest rates. Cardiovascular disease was the leading cause of death in all patients. However, CAG was performed less frequently in patients with non-active- and active cancer, irrespective of cancer type – altogether indicating the importance of incorporating cancer type and status, when planning treatment strategy.

Funding Acknowledgement
Type of funding sources: Foundation. Main funding source(s): Karen Elise Jensen Foundation and Helsefonden