Malignancy in patients with myocardial infarction and non-obstructive coronary arteries: A systematic review and meta-regression

Coronary artery thromboembolism as a cause of myocardial infarction with non-obstructive coronary arteries (MINOCA)

Acute myocardial infarction (AMI) usually represents the clinical manifestation of atherothrombotic coronary artery disease (CAD) resulting from atherosclerotic plaque rupture. However, there are cases in which coronary angiography or coronary computed tomography angiography reveals patients with acute coronary syndrome with non-obstructive CAD. This clinical entity is defined as myocardial infarction with non-obstructive coronary arteries (MINOCA) and often considered as a clinical dynamic working diagnosis that needs further investigations for the establishment of a final etiologic diagnosis. The main causes of a MINOCA working diagnosis include atherosclerotic, non-atherosclerotic (vessel-related and non-vessel-related), and thromboembolic causes This literature review aimed to investigate the major thromboembolic causes in patients presenting with MINOCA regarding their etiology and pathophysiologic mechanisms, as well as diagnostic and treatment methods.

Coronary microvascular dysfunction and cancer therapy-related cardiovascular toxicity

BACKGROUND

Coronary microvascular dysfunction (CMD) has been implicated as a potential mechanism in the pathophysiology of different clinical presentations, including ischemia and no obstructive coronary artery disease (INOCA), myocardial infarction and nonobstructive coronary arteries (MINOCA), stress cardiomyopathy, heart failure, and myocarditis. There are limited data about the role of CMD in cancer therapy-related cardiovascular toxicities.

CASE PRESENTATIONS

Four women with a diagnosis of active cancer receiving treatment who developed subsequent MINOCA or INOCA presented for cardiac catheterization. Upon coronary angiography showing no obstructive coronary arteries, coronary function testing was performed to evaluate for CMD.

METHODS

Coronary physiology was assessed measuring non-hyperemic (resting full-cycle ratio [RFR]) and hyperemic (fractional flow reserve [FFR]) indices using a physiologic pressure wire. The wire also measured coronary flow reserve (CFR), index of microcirculatory resistance (IMR), and RFR using thermodilution technology. CMD was confirmed if the CFR was <2.5 and the IMR was >25.

RESULTS

Among 4 patients with diagnosis of active cancer presenting with chest pain, there was no evidence of obstructive coronary artery disease, leading to separate diagnoses of INOCA, MINOCA, stress cardiomyopathy, and myocarditis. We found CMD in 2 patients (1 with INOCA and 1 with immune checkpoint inhibitor-related myocarditis).

CONCLUSIONS

CMD may play a role in cardiovascular toxicities. Further coronary physiology studies are needed to understand the mechanisms of cancer therapy-related cardiovascular toxicity and CMD, as well as optimal preventive and treatment options.

Clinical Characteristics and Long-Term Outcomes of MINOCA Accompanied by Active Cancer: A Retrospective Insight Into a Cardio-Oncology Center Registry

Background

Clinical characteristics and long-term outcomes of patients with myocardial infarction with non-obstructive coronary arteries (MINOCA) and cancer are insufficiently elucidated.

Objectives

We sought to characterize these patients hospitalized in a tertiary cardio-oncology center and to find the potential determinants affecting their long-term mortality.

Methods

MINOCA was diagnosed in 72 of the 1,011 patients with consecutive myocardial infarction who underwent coronary angiography. Mortality rates and their determinants were analyzed within a median follow-up of 69.2 (37.8-79.9) months.

Results

Active cancer was identified in 21 (29.2%) of patients with MINOCA and in 113 (12.0%) patients with myocardial infarction and obstructive coronary artery disease (MI-CAD) (p < 0.001). MINOCA patients with cancer were characterized by a higher incidence of anemia (47.6 vs. 21.6%, p = 0.03) and more frequently Takotsubo syndrome (19.1 vs. 2.0%, p = 0.01) than in non-cancer MINOCA. The troponin T/hemoglobin ratio was higher in both cancer MINOCA and MI-CAD groups when compared with their respective non-cancer patients (both p < 0.05). The age and sex-standardized mortality rates were significantly higher in cancer MINOCA (26.7%/year) when compared with non-cancer MINOCA (2.3%/year, p = 0.002) and in cancer MI-CAD (25.0%/year) vs. non-cancer MI-CAD (3.7%/year, p < 0.001). Active cancer (HR 3.12, 95% CI 2.41-4.04) was independently associated with higher long-term mortality, while higher hemoglobin levels (HR 0.93, 95% CI 0.88-0.99, per g/dl) and a MINOCA diagnosis (HR 0.69, 95% CI 0.47-0.97) improved long-term survival.

Conclusion

Patients with MINOCA were comorbid with cancer more frequently than MI-CAD. In turn, an active malignancy was associated with an unfavorable long-term survival both in MI-CAD population and in patients with MINOCA.

New Insights on the Toxicity on Heart and Vessels of Breast Cancer Therapies

Cardiovascular diseases are largely represented in patients with cancer and appear to be important side effects of cancer treatments, heavily affecting quality of life and leading to premature morbidity and death among cancer survivors. In particular, treatments for breast cancer have been shown to potentially play serious detrimental effects on cardiovascular health. This review aims to explore the available literature on breast cancer therapy-induced side effects on heart and vessels, illustrating the molecular mechanisms of cardiotoxicity known so far. Moreover, principles of cardiovascular risk assessment and management of cardiotoxicity in clinical practice will also be elucidated. Chemotherapy (anthracycline, taxanes, cyclophosphamide and 5-fluorouracil), hormonal therapy (estrogen receptor modulator and gonadotropin or luteinizing releasing hormone agonists) and targeted therapy (epidermal growth factor receptor 2 and Cyclin-dependent kinases 4 and 6 inhibitors) adverse events include arterial and pulmonary hypertension, supraventricular and ventricular arrhythmias, systolic and diastolic cardiac dysfunction and coronary artery diseases due to different and still not well-dissected molecular pathways. Therefore, cardiovascular prevention programs and treatment of cardiotoxicity appear to be crucial to improve morbidity and mortality of cancer survivors.

Myocardial Infarction With Non-obstructive Coronary Arteries: Risk Factors and Associated Comorbidities

Myocardial infarction with non-obstructive coronary arteries (MINOCA), despite a lower burden of coronary atherosclerosis, has a non-negligible prognostic impact. The label of MINOCA includes an array of different aetiologies and pathologic conditions, thus the identification of the underlying disease is crucial to patient management. Myocardial infarction with obstructive coronary artery disease and MINOCA share only some risk factors and comorbid conditions. While traditional cardiovascular risk factors have a lower prevalence in MINOCA patients, atypical ones—e.g., anxiety, depression, and autoimmune diseases—are much more frequent in this population. Other conditions—e.g., pregnancy, cancer, and anti-cancer therapy—can predispose to or even induce MINOCA through various mechanisms. The evidence of such risk factors for MINOCA is still scarce and contradicting, as no randomised controlled trials exist in this field. In our work, we performed a review of registries, clinical studies, and case reports of MINOCA, in order to summarise the available data and analyse its possibile pathogenic mechanisms.

Comparing pharmacotherapy in MINOCA versus medically managed obstructive acute coronary syndrome

Most prior studies have compared myocardial infarction with non-obstructive coronary arteries (MINOCA), to obstructive acute coronary syndrome (ACS) often requiring revascularisation. However, these were subject to treatment bias given the significant differences in management. This study uniquely compares the management and outcomes of MINOCA patients with a medically managed obstructive ACS (M-ACS) population. We retrospectively analysed registry data for consecutive patients admitted to the Gold Coast University Hospital with ACS requiring coronary angiography and identified patients with MINOCA and M-ACS. Baseline characteristics, pharmacological therapy and in-hospital outcomes were compared. In hospital outcomes were composite NACE, heart failure, stroke and major bleeding. Multivariate regression analysis was also performed to identify independent predictors of MINOCA. Multivariate regression analysis was also performed to identify independent predictors of MINOCA. We identified 139 patients with MINOCA and 142 patients with medically managed obstructive ACS (M-ACS). Multivariate regression analysis also identified female sex and cancer as independent predictors of MINOCA with odds ratios of 5.57 and 3.01, respectively. MINOCA patients were significantly less likely to receive cardioprotective medications at admission and discharge, specifically aspirin, beta-blockers, ACE-I and statins, compared to those with M-ACS. While mortality was higher among M-ACS patients (0.0% vs. 3.6%; p = 0.03), no significant differences were noted for composite NACE, heart failure, stroke and major bleeding. MINOCA patients have similar outcomes to M-ACS. Despite this, we noted a discrepancy in the use of cardioprotective medications. We also identified female sex and cancer were independent predictors of MINOCA. This may represent a missed opportunity to prevent adverse events among patients with MINOCA. Large, randomised trials are required to provide more definitive evidence.