Author + information
- Ezequiel Munoz, MD,
- Gloria Iliescu, MD,
- Pimprapa Vejpongsa, MD,
- Konstantinos Charitakis, MD,
- Kaveh Karimzad, MD,
- Juan Lopez-Mattei, MD,
- Syed Wamique Yusuf, MD,
- Konstantinos Marmagkiolis, MD and
- Cezar Iliescu, MD∗ ()
- ↵∗Department of Cardiology, The University of Texas MD Anderson Cancer Center at Houston, 1515 Holcombe Boulevard, Houston, Texas 77030
Takotsubo stress cardiomyopathy (TSC) is a clinical condition that mimics acute coronary syndrome (ACS). It has been extensively studied in the general population; however, few cases have been reported in cancer patients. The recent study by Tornvall et al. (1) prompted us to perform an additional analysis on TSC in cancer patients. The institutional review board approved the study.
In the present study, we compared mortality in cancer patients with TSC with non–ST-segment elevation myocardial infarction (NSTEMI) as a control group. We included all patients with presumed NSTEMI from the cardiac catheterization laboratory database at a tertiary cancer center over a 6-year period (December 2008 to December 2014). Patients were identified that fulfilled the diagnostic criteria for TSC: 1) suspected ACS with chest pain, electrocardiography changes, or elevation of cardiac enzymes; 2) transient left ventricular wall motion abnormalities extending beyond a single epicardial vascular distribution; 3) absence of coronary stenosis that could have caused ACS, according to angiography; and 4) no clinical evidence of myocarditis or pheochromocytoma (2). Patient demographic characteristics, cancer type, atherosclerosis risk factors, and triggering factors were obtained from electronic medical records. For every patient with TSC, 2 control subjects diagnosed with NSTEMI who matched for age, sex, cancer diagnosis, and cardiovascular risk factor were selected from the database.
The cause of death was investigated and classified as cardiac (resulting from an acute myocardial infarction, sudden cardiac death, or other cardiovascular causes) or cancer related (those occurred in hospice or palliative care). Follow-up data and outcomes were obtained by team members through clinical visits, medical records, or telephone interviews. The cause of death was ascertained by review of the available medical records.
Overall survival (OS) (time interval from procedure to death or last follow-up), cancer-specific survival (time interval from procedure to cancer-related death or last follow-up), and cardiac-specific survival (time interval from procedure to cardiac-related death or last follow-up) were calculated, and the Kaplan-Meier method and log-rank test were used to compare them between the 2 disease groups. Univariate Cox proportional hazards regression analyses were conducted to identify variables that were associated with OS. Multivariable analysis was not performed due to small number of events.
Of 275 patients identified, 30 patients who met the inclusion criteria for TSC and 60 matched control NSTEMI patients were included. In the TSC group, 73% were women and the mean age was 65 ± 9 years. The underlying cancer was solid tumors in 76% of patients and hematologic malignancies in 24%. The triggering factor was identified as the cancer therapy in 57% of patients (surgery in 33%, chemotherapy in 17%, and radiation in 7%), acute illness in 13% of patients, and emotional stress in 30% of patients. Baseline ejection fraction was significantly different between the 2 groups (p = 0.0002).
Although patients in the NSTEMI group had better OS than did those in the TSC group, the difference was not statistically significant (p = 0.2335) (Figure 1). Likewise, patients in the NSTEMI group had better cancer-specific survival than did those in the TSC group, but the difference was not statistically significant (p = 0.1530). Univariate Cox regression showed that none of the variables were significantly associated with OS (all p values >0.05). For patients in the TSC group, OS was compared between 2 types of cancer diagnoses (hematologic tumors and solid malignancies), and a significant difference was not detected (p = 0.9328).
Our study showed that more than 10% of patients with cancer who exhibited clinical characteristics of NSTEMI had TSC. Differentiating between the 2 clinical entities is even more important in patients with cancer than in the general population because this allows early discontinuation of low molecular weight heparin and P2Y12 inhibitors, which could prevent perioperative or chemotherapy-related bleeding complications.
A higher rate of TSC was found in post-menopausal women (67%), with an average age of 65 years, who had minimal cardiovascular risk factors. Previous studies have suggested that the association of TSC with malignancies could be due to cancer treatment rather than the cancer per se (1). Our results support these findings, showing that surgical procedures were the most common trigger of TSC, followed by emotional stress, chemotherapy, other illness, and radiation.
The non–statistically significant difference in survival rates found between patients with cancer in the TSC and NSTEMI groups with similar clinical characteristics suggests that this clinical syndrome is less benign than previously thought, and TSC may represent a detrimental event that affects the overall prognosis of patients with cancer.
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- 2016 American College of Cardiology Foundation