I have carefully read the article by Cordero et al.1 on the postdischarge prevalence and incidence of malignant tumors in patients with acute coronary syndrome (ACS), and I would like to congratulate the authors for addressing a subject that has been little studied to date, but is of great interest to cardio-oncology departments.
The first finding of note in this study was that the on-admission prevalence of cancer in patients admitted for an ACS was 3.4% and that the postdischarge incidence of cancer was 3.1% (median follow-up of 33 months). In summary, 6.5% of patients admitted for an ACS have had or will have cancer. However, it is expected that the prevalence of cancer in patients with ACS will increase in the coming years. In fact, cardiovascular disease is currently an important cause of morbidity and mortality in cancer patients,2,3 for which there are main 2 reasons: the increased survival of cancer patients, because of early detection programs and advances in antitumor treatments4; and because cancer and cardiovascular disease have numerous risk factors in common.5 In fact, the present study found no differences between the percentage of patients with or without cancer with a history of smoking, hypertension, dyslipidemia, or diabetes.
The second truly striking and novel finding of the present study was the increase in mortality observed in patients with prevalent and incident malignant tumors. In patients with de novo tumors, the increase in mortality was mainly due to an increase in noncardiovascular mortality (subhazard ratio [sHR], 33.03; 95% confidence interval [95%CI] 20.32-53.67).
Although this finding could suggest that the role of cardiologists would be minimal in this patient subgroup, analysis of these results should be deepened. It is unclear from the present study whether the noncardiovascular mortality rate of patients with de novo tumors was expected, given their underlying oncological disease or, on the contrary, whether it was higher than expected. It would therefore be interesting to investigate whether the increase in noncardiovascular mortality in patients with cancer and a history of ischemic heart disease could be due to the use of less aggressive treatments for their disease, such as lower surgical intervention rates, lower use of chemotherapy treatments, or increased use of second-line chemotherapy with less curative capacity but fewer adverse cardiovascular effects. For this reason, “cardio-oncologists” should also play an active role in assessing the stability and severity of cardiovascular disease in this patient subgroup, and thus in assessing the risk/benefit of initiating certain chemotherapeutic treatments.
In contrast, the increase in mortality in the patients with prevalent tumors was due to an increase in both noncardiovascular mortality (sHR = 11.53; 95%CI, 6.07-21.89) and cardiovascular mortality (sHR=2.21; 95%CI, 1.12-4.33). The authors attribute the increase in cardiovascular mortality to a lower revascularization rate and a decreased use of drug-eluting stents. To date, no data are available on the prognosis of patients with active tumors who are admitted with ACS and undergo invasive diagnostic and therapeutic procedures.6 The presence of cancer may limit the use of cardiac catheterization because of frailty caused by aggressive chemotherapy treatments in these patients. Similarly, thrombocytopenia secondary to myelosuppressive chemotherapy or in patients with blood cancers could explain the decreased use of drug-eluting stents due to the need to limit the duration of dual platelet antiplatelet therapy.
The results of this study should provide a starting point to initiate strategies in cardio-oncology units to reduce cardiovascular mortality in patients with ACS and prevalent malignant tumors and to reduce noncardiovascular mortality in patients with de novo tumors following an ACS.7
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