Coronary vasomotor dysfunction in cancer survivors treated with thoracic irradiation

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.

Potential utility of myocardial blood flow quantification with single photon emission computed tomography in a patient undergoing treatment for breast cancer

Diagnosis and management of cardiac complications of cancer treatment can be challenging. Few PET data suggest a potential role of dynamic perfusion imaging with measurements of absolute myocardial blood flow and flow reserve (MFR). We report the case of a 72-year-old woman with a history of bilateral breast cancer who underwent dynamic cardiac scintigraphy. Relative perfusion analysis was normal, whereas MFR was impaired in all territories suggesting diffuse microvascular dysfunction. Flow parameters derived from dynamic cardiac scintigraphy could thus be an interesting tool in cardio-oncology.

Tales from the future-nuclear cardio-oncology, from prediction to diagnosis and monitoring

Cancer and cardiovascular diseases (CVD) often share common risk factors, and patients with CVD who develop cancer are at high risk of experiencing major adverse cardiovascular events. Additionally, cancer treatment can induce short- and long-term adverse cardiovascular events. Given the improvement in oncological patients' prognosis, the burden in this vulnerable population is slowly shifting towards increased cardiovascular mortality. Consequently, the field of cardio-oncology is steadily expanding, prompting the need for new markers to stratify and monitor the cardiovascular risk in oncological patients before, during, and after the completion of treatment. Advanced non-invasive cardiac imaging has raised great interest in the early detection of CVD and cardiotoxicity in oncological patients. Nuclear medicine has long been a pivotal exam to robustly assess and monitor the cardiac function of patients undergoing potentially cardiotoxic chemotherapies. In addition, recent radiotracers have shown great interest in the early detection of cancer-treatment-related cardiotoxicity. In this review, we summarize the current and emerging nuclear cardiology tools that can help identify cardiotoxicity and assess the cardiovascular risk in patients undergoing cancer treatments and discuss the specific role of nuclear cardiology alongside other non-invasive imaging techniques.

Cancer and Postradiotherapy Cardiotoxicity: How to Face Damage in Women’s Hearts?

Cancer and cardiovascular disease are the two main causes of death worldwide in both men and women. In the past decades, survival rate in cancer patients has substantially improved due to new treatments and developments in radiation therapy (RT). In women, breast cancer (BC) is the leading cause of cancer death and thoracic RT is a main component of the treatment in many cases. Nevertheless, despite new techniques that limit the area receiving RT, cardiac damage is still an important concern in BC patients. In this review, the following aspects will be addressed: pathophysiology of postradiotherapy heart damage in women with BC; mechanisms, diagnosis and prevention/management of heart damage; and future areas of potential research for radiotherapy injury in women.

Coronary vasomotor dysfunction portends worse outcomes in patients with breast cancer

BACKGROUND

Impaired MFR in the absence of flow-limiting CAD is associated with adverse events. Cardiovascular disease is an important cause of morbidity and mortality in patients with breast cancer. We sought to test the utility of MFR to predict outcomes in a cohort of patients with breast cancer.

METHODS

We retrospectively studied consecutive patients with breast cancer or breast cancer survivors who underwent cardiac stress PET imaging from 2006 to 2017 at Brigham and Women's Hospital. Patients with a history of clinically overt CAD, LVEF < 45%, or abnormal myocardial perfusion were excluded. Subjects were followed from time of PET to the occurrence of a first major adverse cardiovascular event (MACE) and all-cause death.

RESULTS

The final cohort included 87 patients (median age 69.0 years, 98.9% female, mean MFR 2.05). Over a median follow-up of 7.6 years after PET, the lowest MFR tertile was associated with higher cumulative incidence of MACE (adjusted subdistribution hazard ratio 4.91; 95% CI 1.68-14.38; p = 0.004) when compared with the highest MFR tertile.

CONCLUSIONS

In patients with breast cancer, coronary vasomotor dysfunction was associated with incident cardiovascular events. MFR may have potential as a risk stratification biomarker among patients with/survivors of breast cancer.