Chemotherapy acutely impairs neurovascular and hemodynamic responses in women with breast cancer

Therapy-naïve malignancy causes cardiovascular disease: a state-of-the-art cardio-oncology perspective

Cardiovascular disease (CVD) and cancer are the leading causes of mortality worldwide. Although generally thought of as distinct diseases, the intersectional overlap between CVD and cancer is increasingly evident in both causal and mechanistic relationships. The field of cardio-oncology is largely focused on the cardiotoxic effects of cancer therapies (e.g., chemotherapy, radiation). Furthermore, the cumulative effects of cardiotoxic therapy exposure and the prevalence of CVD risk factors in patients with cancer lead to long-term morbidity and poor quality of life in this patient population, even when patients are cancer-free. Evidence from patients with cancer and animal models demonstrates that the presence of malignancy itself, independent of cardiotoxic therapy exposure or CVD risk factors, negatively impacts cardiac structure and function. As such, the primary focus of this review is the cardiac pathophysiological and molecular features of therapy-naïve cancer. We also summarize the strengths and limitations of preclinical cancer models for cardio-oncology research and discuss therapeutic strategies that have been tested experimentally for the treatment of cancer-induced cardiac atrophy and dysfunction. Finally, we explore an adjacent area of interest, called "reverse cardio-oncology," where the sequelae of heart failure augment cancer progression. Here, we emphasize the cross-disease communication between malignancy and the injured heart and discuss the importance of chronic low-grade inflammation and endocrine factors in the progression of both diseases.

[Particularities of arterial stiffness dynamics on the background of breast cancer chemotherapy]

BACKGROUND

Modern breast cancer chemotherapy regimens (BC) consider individual patient parameters and ranges of cardiotoxic doses. However, clinicians often record clinical and laboratory-instrumental signs of cardio- and vasculotoxicity in patients, which emphasizes the high importance of searching for markers of early toxic response.

AIM

To study the characteristics of the response of arterial stiffness on the background of anthracycline-containing chemotherapy to determine potential markers of vasculotoxicity in BC patients.

MATERIALS AND METHODS

20 women with a BC were included. The patients received 4 cycles of chemotherapy in the doxorubicin + cyclophosphane (AC) regimen with an interval of 2-3 weeks, then they were injected with paclitaxel weekly for 12 injections, or docetaxel once every 3 weeks. All patients underwent TTE, arterial stiffness determination by the "gold standard" method and using volumetric sphygmography before the start of treatment, after the completion of the anthracycline component and after the end of taxanes.

RESULTS

The average age of the patients was 45.5±5.31 years. After completing the course of anthracyclines, there was a significant increase in heart rate (from 65.6±9.3 to 73.3±10.1 beats/min.), a decrease in SBP (from 122.6±9.9 to 116.5±12.3 mmHg) and DBP (from 78.9±8.5 to 76.2±8.6 mmHg), a decrease in carotid femoral pulse wave velocity (cfPWV) (from 9.32±1.41 to 7.85±1.57 m/s), CAVI index on the left (from 6.78±0.81 to 6.5±0.88), the velocity of the cardio-ankle pulse wave on the right and left (from 6.7±0.6 to 6.5±0.7 m/s; from 7.0±0.6 to 6.3±0.8 m/sc, respectively). After the completion of the taxane, there was a tendency to increase these indicators, however, they remained significantly lower compared to the values before the start of treatment.

CONCLUSION

A comparative analysis of arterial stiffness indicators at different stages of chemotherapy showed a more pronounced reaction of cfPWV, CAVI, cardio-ankle pulse wave to the administration of anthracyclines, which presumably may be associated with concomitant hemodynamic restructuring.

Neurovascular and hemodynamic responses to mental stress and exercise in severe COVID-19 survivors

Previous studies show that COVID-19 survivors have elevated muscle sympathetic nerve activity (MSNA), endothelial dysfunction, and aortic stiffening. However, the neurovascular responses to mental stress and exercise are still unexplored. We hypothesized that COVID-19 survivors, compared with age- and body mass index (BMI)-matched control subjects, exhibit abnormal neurovascular responses to mental stress and physical exercise. Fifteen severe COVID-19 survivors (aged: 49 ± 2 yr, BMI: 30 ± 1 kg/m2) and 15 well-matched control subjects (aged: 46 ± 3 yr, BMI: 29 ± 1 kg/m2) were studied. MSNA (microneurography), forearm blood flow (FBF), and forearm vascular conductance (FVC, venous occlusion plethysmography), mean arterial pressure (MAP, Finometer), and heart rate (HR, ECG) were measured during a 3-min mental stress (Stroop Color-Word Test) and during a 3-min isometric handgrip exercise (30% of maximal voluntary contraction). During mental stress, MSNA (frequency and incidence) responses were higher in COVID-19 survivors than in controls (P < 0.001), and FBF and FVC responses were attenuated (P < 0.05). MAP was similar between the groups (P > 0.05). In contrast, the MSNA (frequency and incidence) and FBF and FVC responses to handgrip exercise were similar between the groups (P > 0.05). MAP was lower in COVID-19 survivors (P < 0.05). COVID-19 survivors exhibit an exaggerated MSNA and blunted vasodilatory response to mental challenge compared with healthy adults. However, the neurovascular response to handgrip exercise is preserved in COVID-19 survivors. Overall, the abnormal neurovascular control in response to mental stress suggests that COVID-19 survivors may have an increased risk to cardiovascular events during mental challenge.

Vascular Inflammation, Cancer, and Cardiovascular Diseases

PURPOSE OF REVIEW

Cancer and cardiovascular disease are among the leading causes of morbidity and mortality in the USA. Cancer and cardiovascular disease have inflammatory underpinnings that have been associated with both the development and progression of these disease states.

RECENT FINDINGS

Inflammatory signaling has been found to be a critical event in both cardiovascular disease and cancer formation and progression. Further, many chemotherapeutic agents potentiate inflammation exacerbating existing cardiovascular disease or leading to its presence. The exact mechanisms of these interactions remain poorly understood. The proinflammatory milieu observed in both cancer and cardiovascular disease likely plays an important role in the development and potentiation of both conditions. Further evaluation of this relationship will be critical in the development of new diagnostic and therapeutic modalities.

Predictors of cognitive impairment in patients undergoing ileostomy for colorectal cancer: a retrospective analysis

Background

Early detection of cognitive impairment in patients undergoing ileostomy for colorectal cancer may help improve patient outcomes and quality of life. Identifying risk factors and clinically accessible factors is crucial for prevention and treatment.

Objective

This retrospective study aimed to identify risk factors for post-operative cognitive impairment in patients undergoing ileostomy for colorectal cancer and to explore potential factors for its prevention and treatment.

Methods

A total of 108 cases were selected and included in the study. Patient data including general characteristics, disease stage, complications, and chemotherapy status were collected, and sleep quality and cognitive function were assessed using questionnaires and follow-up. Patients were randomly divided into training and validation groups. A random forest model was used to rank clinical features based on their contribution to predicting the prognosis of cancer-related cognitive impairment (CRCI). Nomograms were constructed using the support vector machine-recursive feature elimination (SVM-RFE) method, and the minimal root-mean-square error (RMSE) values were compared to select the best model. Regression analysis was performed to determine independent predictors.

Results

Significant differences were observed in age, body mass index (BMI), alcohol consumption, frequency of physical activity, comorbidity, and cancer-related anemia (CRA) between the CRCI and non-CRCI groups. Random forest analysis revealed that age, BMI, exercise intensity, PSQI scores, and history of hypertension were the most significant predictors of outcome. Univariate logistic regression analysis of 18 variables revealed that age, alcohol consumption, exercise intensity, BMI, and comorbidity were significantly associated with the outcome of CRCI (p < 0.05). Univariate and multivariate models with P-values less than 0.1 and 0.2, respectively, showed better predictive performance for CRCI. The results of univariate analysis were plotted on a nomogram to evaluate the risk of developing CRCI after colorectal cancer surgery. The nomogram was found to have good predictive performance. Finally, regression analysis revealed that age, exercise intensity, BMI, comorbidity, and CRA were independent predictors of CRCI.

Conclusions

This retrospective cohort study revealed that age, exercise intensity, BMI, comorbidity, CRA, and mobility are independent predictors of cognitive impairment in patients undergoing ileostomy for colorectal cancer. Identifying these factors and potential factors may have clinical implications in predicting and managing post-operative cognitive impairment in this patient population.

Can global longitudinal strain (GLS) with magnetic resonance prognosticate early cancer therapy-related cardiac dysfunction (CTRCD) in breast cancer patients, a prospective study?

PURPOSE

To determine if Artificial Intelligence-based computation of global longitudinal strain (GLS) from left ventricular (LV) MRI is an early prognostic factor of cancer therapy-related cardiac dysfunction (CTRCD) in breast cancer patients. The main hypothesis based on the patients receiving antineoplastic chemotherapy treatment was CTRCD risk analysis with GLS that was independent of LV ejection fraction (LVEF).

METHODS

Displacement Encoding with Stimulated Echoes (DENSE) MRI was acquired on 32 breast cancer patients at baseline and 3- and 6-month follow-ups after chemotherapy. Two DeepLabV3+ Fully Convolutional Networks (FCNs) were deployed to automate image segmentation for LV chamber quantification and phase-unwrapping for 3D strains, computed with the Radial Point Interpolation Method. CTRCD risk (cardiotoxicity and adverse cardiac events) was analyzed with Cox Proportional Hazards (PH) models with clinical and contractile prognostic factors.

RESULTS

GLS worsened from baseline to the 3- and 6-month follow-ups (-19.1 ± 2.1%, -16.0 ± 3.1%, -16.1 ± 3.0%; P < 0.001). Univariable Cox regression showed the 3-month GLS significantly associated as an agonist (hazard ratio [HR]-per-SD: 2.1; 95% CI: 1.4-3.1; P < 0.001) and LVEF as a protector (HR-per-SD: 0.8; 95% CI: 0.7-0.9; P = 0.001) for CTRCD occurrence. Bivariable regression showed the 3-month GLS (HR-per-SD: 2.0; 95% CI: 1.2-3.4; P = 0.01) as a CTRCD prognostic factor independent of other covariates, including LVEF (HR-per-SD: 1.0; 95% CI: 0.9-1.2; P = 0.9).

CONCLUSIONS

The end-point analyses proved the hypothesis that GLS is an early, independent prognosticator of incident CTRCD risk. This novel GLS-guided approach to CTRCD risk analysis could improve antineoplastic treatment with further validation in a larger clinical trial.

Sympathetic Neural Overdrive, Aortic Stiffening, Endothelial Dysfunction, and Impaired Exercise Capacity in Severe COVID-19 Survivors: A Mid-Term Study of Cardiovascular Sequelae

BACKGROUND

COVID-19 has become a dramatic health problem during this century. In addition to high mortality rate, COVID-19 survivors are at increased risk for cardiovascular diseases 1-year after infection. Explanations for these manifestations are still unclear but can involve a constellation of biological alterations. We hypothesized that COVID-19 survivors compared with controls exhibit sympathetic overdrive, vascular dysfunction, cardiac morpho-functional changes, impaired exercise capacity, and increased oxidative stress.

METHODS

Nineteen severe COVID-19 survivors and 19 well-matched controls completed the study. Muscle sympathetic nerve activity (microneurography), brachial artery flow-mediated dilation and blood flow (Doppler-Ultrasound), carotid-femoral pulse wave velocity (Complior), cardiac morpho-functional parameters (echocardiography), peak oxygen uptake (cardiopulmonary exercise testing), and oxidative stress were measured ~3 months after hospital discharge. Complementary experiments were conducted on human umbilical vein endothelial cells cultured with plasma samples from subjects.

RESULTS

Muscle sympathetic nerve activity and carotid-femoral pulse wave velocity were greater and brachial artery flow-mediated dilation, brachial artery blood flow, E/e' ratio, and peak oxygen uptake were lower in COVID-19 survivors than in controls. COVID-19 survivors had lower circulating antioxidant markers compared with controls, but there were no differences in plasma-treated human umbilical vein endothelial cells nitric oxide production and reactive oxygen species bioactivity. Diminished peak oxygen uptake was associated with sympathetic overdrive, vascular dysfunction, and reduced diastolic function in COVID-19 survivors.

CONCLUSIONS

Our study revealed that COVID-19 survivors have sympathetic overactivation, vascular dysfunction, cardiac morpho-functional changes, and reduced exercise capacity. These findings indicate the need for further investigation to determine whether these manifestations are persistent longer-term and their impact on the cardiovascular health of COVID-19 survivors.

Endogenous humoral determinants of vascular endothelial dysfunction as triggers of acute poisoning complications

The vascular endothelium is not only the semipermeable membrane that separates tissue from blood but also an organ that regulates inflammation, vascular tone, blood clotting, angiogenesis and synthesis of connective tissue proteins. It is susceptible to the direct cytotoxic action of numerous xenobiotics and to the acute hypoxia that accompanies acute poisoning. This damage is superimposed on the preformed state of the vascular endothelium, which, in turn, depends on many humoral factors. The probability that an exogenous toxicant will cause life-threatening dysfunction of the vascular endothelium, thereby complicating the course of acute poisoning, increases with an increase in the content of endogenous substances in the blood that disrupt endothelial function. These include ammonia, bacterial endotoxin, indoxyl sulfate, para-cresyl sulfate, trimethylamine N-oxide, asymmetric dimethylarginine, glucose, homocysteine, low-density and very-low-density lipoproteins, free fatty acids and products of intravascular haemolysis. Some other endogenous substances (albumin, haptoglobin, haemopexin, biliverdin, bilirubin, tetrahydrobiopterin) or food-derived compounds (ascorbic acid, rutin, omega-3 polyunsaturated fatty acids, etc.) reduce the risk of lethal vascular endothelial dysfunction. The individual variability of the content of these substances in the blood contributes to the stochasticity of the complications of acute poisoning and is a promising target for the risk reduction measures. Another feasible option may be the repositioning of drugs that affect the function of the vascular endothelium while being currently used for other indications.

Endothelial dysfunction as a complication of anti-cancer therapy

Recent strides in anti-cancer therapeutics have improved longevity and led to a growing population of cancer survivors, who are increasingly likely to die of other causes. Treatment-induced cardiotoxicity is a complication of several therapeutic agents with acute and long-term consequences for cancer patients. Vascular endothelial dysfunction is a precursor and hallmark of ischemic coronary disease and may play a role in anti-cancer therapy-induced cardiotoxicity. This review summarizes clinical evidence for endothelial dysfunction following anti-cancer therapy and extends the discussion to include the impact of therapeutic agents on conduit arteries and the microcirculation. We highlight the role of innate immune system activation and cross-talk between inflammation and oxidative stress as pathogenic mechanisms underlying anti-cancer therapy-induced vascular toxicity. Understanding the impact of anti-cancer agents on the vascular endothelium will inform therapeutic approaches to prevent or reverse treatment-induced cardiotoxicity and may serve as an important tool to predict, monitor, and prevent adverse cardiovascular outcomes in patients undergoing treatment.

Cancer therapy-related cardiac dysfunction: is endothelial dysfunction at the heart of the matter?

Significant improvements in cancer survival have brought to light unintended long-term adverse cardiovascular effects associated with cancer treatment. Although capable of manifesting a broad range of cardiovascular complications, cancer therapy-related cardiac dysfunction (CTRCD) remains particularly common among the mainstay anthracycline-based and human epidermal growth factor receptor-targeted therapies. Unfortunately, the early asymptomatic stages of CTRCD are difficult to detect by cardiac imaging alone, and the initiating mechanisms remain incompletely understood. More recently, circulating inflammatory markers, cardiac biomarkers, microRNAs, and extracellular vesicles (EVs) have been considered as early markers of cardiovascular injury. Concomitantly, the role of the endothelium in regulating cardiac function in the context of CTRCD is starting to be understood. In this review, we highlight the impact of breast cancer therapies on the cardiovascular system with a focus on the endothelium, and examine the status of circulating biomarkers, including inflammatory markers, cardiac biomarkers, microRNAs, and endothelial cell-derived EVs. Investigation of these emerging biomarkers may uncover mechanisms of injury, detect early stages of cardiovascular damage, and elucidate novel therapeutic approaches.

Exacerbated hemodynamic response during exercise in cancer patients prior to autologous hematopoietic stem cell transplantation

PURPOSE

Chemotherapy treatment can lead to cardiovascular toxicity and physical impairment prior to autologous hematopoietic stem cell transplantation (auto-HSCT). Cardiovascular adjustments during exercise and the exercise capacity remain unknown in patients prior to auto-HSCT. Thus, the hemodynamic responses during exercise and exercise capacity were evaluated using a novel effort test in patients prior to auto-HSCT.

METHODS

Thirty patients prior to auto-HSCT (BMT group: 44.6 ± 14.1 years) and 23 control participants (CON group: 43.9 ± 16.6 years) performed the 6-Minute Step Test (6MST) to assess their exercise capacity and the hemodynamic responses during exercise. Systolic and diastolic blood pressure (SBP and DBP), heart rate (HR), and oxygen saturation (SpO₂) were measured during the test. Rate-pressure product (RPP) was calculated multiplying SBP by HR. The highest HR value recorded during the test was compared with the maximum HR predicted by age and was used as % of maximum HR (%HRmax).

RESULTS

The number of steps up and down performed by the BMT group was lower than CON (108.8 ± 25.3 vs. 127.5 ± 34.4 steps, P = 0.02). The BMT group showed a higher magnitude of increase in SBP and RPP during the 6MST when compared to CON (ΔSBP: 18.5 ± 11.45 vs. 8.30 ± 18.46 mmHg, P = 0.01; and ΔRPP: 8197.3 ± 3829.1 vs. 6170.9 ± 3568.9 mmHg beats min^-1, P = 0.05). The BMT group exhibited higher SpO2 and HR values throughout the protocol (P < 0.05), reaching a higher %HRmax than CON group (76.9 ± 9.6 vs. 66.4 ± 8.9%, P < 0.01).

CONCLUSIONS

Patients with indication for auto-HSCT have exacerbated chronotropic and pressor responses during exercise and reduced exercise capacity in the 6MST.

Effect of exercise training on cardiovascular autonomic and muscular function in subclinical Chagas cardiomyopathy: a randomized controlled trial

PURPOSE

Patients with chronic chagasic cardiomyopathy with preserved ventricular function present with autonomic imbalance. This study evaluated the effects of exercise training (ET) in restoring peripheral and cardiac autonomic control and skeletal muscle phenotype in patients with subclinical chronic chagasic cardiomyopathy.

METHODS

This controlled trial (NCT02295215) included 24 chronic chagasic cardiomyopathy patients who were randomized www.random.org/lists/ into two groups: those who underwent exercise training (n = 12) and those who continued their usual activities (n = 12). Eight patients completed the exercise training protocol, and 10 patients were clinically followed up for 4 months. Muscular sympathetic nerve activity was measured by microneurography and muscle blood flow (MBF) using venous occlusion plethysmography. The low-frequency component of heart rate variability in normalized units (LFnuHR) reflects sympathetic activity in the heart, and the low-frequency component of systolic blood pressure variability in normalized units reflects sympathetic activity in the vessels. The infusion of vasoactive drugs (phenylephrine and sodium nitroprusside) was used to evaluate cardiac baroreflex sensitivity, and a vastus lateralis muscle biopsy was performed to evaluate atrogin-1 and MuRF-1 gene expression.

RESULTS

The baroreflex sensitivity for increases (p = 0.002) and decreases (p = 0.02) in systolic blood pressure increased in the ET group. Muscle blood flow also increased only in the ET group (p = 0.004). Only the ET group had reduced resting muscular sympathetic nerve activity levels (p = 0.008) and sympathetic activity in the heart (LFnu; p = 0.004) and vessels (p = 0.04) after 4 months. Regarding skeletal muscle, after 4 months, participants in the exercise training group presented with lower atrogin-1 gene expression than participants who continued their activities as usual (p = 0.001). The reduction in muscular sympathetic nerve activity was positively associated with reduced atrogin-1 (r = 0.86; p = 0.02) and MuRF-1 gene expression (r = 0.64; p = 0.06); it was negatively associated with improved baroreflex sensitivity both for increases (r = -0.72; p = 0.020) and decreases (r = -0.82; p = 0.001) in blood pressure.

CONCLUSIONS

ET improved cardiac and peripheral autonomic function in patients with subclinical chagasic cardiomyopathy. ET reduced MSNA and sympathetic activity in the heart and vessels and increased cardiac parasympathetic tone and baroreflex sensitivity. Regarding peripheral muscle, after 4 months, patients who underwent exercise training had an increased cross-sectional area of type I fibers and oxidative metabolism of muscle fibers, and decreased atrogin-1 gene expression, compared to participants who continued their activities as usual. In addition, the reduction in MSNA was associated with improved cardiac baroreflex sensitivity, reduced sympathetic cardiovascular tone, and reduced atrogin-1 and MuRF-1 gene expression.

TRIAL REGISTRATION

ID: NCT02295215. Registered in June 2013.

Adjuvant Treatment with 5-Fluorouracil and Oxaliplatin Does Not Influence Cardiac Function, Neurovascular Control, and Physical Capacity in Patients with Colon Cancer

BACKGROUND

Adjuvant chemotherapy with 5-fluorouracil (5-FU) and oxaliplatin increases recurrence-free and overall survival in patients with colon adenocarcinoma. It is known that these drugs have been associated with cardio- and neurotoxicity. We investigated the effects of 5-FU ± oxaliplatin on cardiac function, vascular responses, neurovascular control, and physical capacity in patients with colon cancer.

METHODS

Twenty-nine patients with prior colectomy for stage II-III adenocarcinoma and clinical indication for adjuvant chemotherapy were allocated to receive 5-FU (n = 12) or 5-FU + oxaliplatin (n = 17), according to the oncologist's decision. All the analyses were performed just before and after the end of chemotherapy. Cardiac function was assessed by echocardiography and speckle tracking, and cardiac autonomic control was assessed by heart rate variability (HRV). Vascular endothelial function was assessed by flow-mediated dilation (FMD). Muscle sympathetic nerve activity (MSNA) was directly recorded by microneurography technique, and muscle blood flow by venous occlusion plethysmography. Physical capacity was evaluated by cardiopulmonary exercise test.

RESULTS

Chemotherapy (pooled data) did not significantly change left ventricular ejection fraction (58 ± 1 vs. 55 ± 2%, p = .14), longitudinal strain (-18 ± 1 vs. -18 ± 1%, p = .66), and HRV. Likewise, chemotherapy did not significantly change FMD, muscle blood flow, and MSNA (33 ± 2 vs. 32 ± 1 bursts/min, p = .31). Physical capacity was not significantly changed in both groups. Similar findings were observed when the patients were subdivided in 5-FU and 5-FU + oxaliplatin treatment groups. 5-FU and 5-FU + oxaliplatin did not significantly change cardiac function, HRV, vascular responses, MSNA, and physical capacity.

CONCLUSION

This study provides evidence that adjuvant treatment with 5-FU ± oxaliplatin is well tolerated and does not promote changes compatible with long-term cardiotoxicity.

IMPLICATIONS FOR PRACTICE

Adjuvant chemotherapy with 5-fluorouracil (5-FU) and oxaliplatin increases recurrence-free and overall survival in patients with colon adenocarcinoma; however, these drugs have been associated with cardio- and neurotoxicity. This study investigated the effects of these drugs on cardiac function, vascular responses, neurovascular control, and physical capacity in patients with colon cancer. It was found that 5-FU and oxaliplatin did not significantly change cardiac function, cardiac autonomic control, vascular endothelial function, muscle sympathetic nerve activity, and physical capacity. This study provides evidence that adjuvant treatment with 5-FU ± oxaliplatin is well tolerated and does not promote changes compatible with long-term cardiotoxicity.

Detrimental effects of chemotherapy on human coronary microvascular function

Chemotherapy (CT) is a necessary treatment to prevent the growth and survival of cancer cells. However, CT has a well-established adverse impact on the cardiovascular (CV) system, even years after cessation of treatment. The effects of CT drugs on tumor vasculature have been the focus of much research, but little evidence exists showing the effects on the host microcirculation. Microvascular (MV) dysfunction is an early indicator of numerous CV disease phenotypes, including heart failure. The goal of this study was to evaluate the direct effect of doxorubicin (Dox) on human coronary MV function. To study the effect of CT on the cardiac MV function, flow-mediated dilation (FMD), pharmacologically-induced endothelial dependent dilation to acetylcholine (ACh), and smooth muscle-dependent dilation to papaverine were investigated. Vessels were freshly isolated from atrial appendages of adult patients undergoing cardiopulmonary bypass surgery or from cardiac tissue of pediatric patients, collected at the time of surgery to repair congenital heart defects. Isolated vessels were incubated in endothelial culture medium containing vehicle or Dox (100 nm, 15-20 h) and used to measure dilator function by video microscopy. Ex vivo treatment of adult human coronary microvessels with Dox significantly impaired flow-mediated dilation (FMD). Conversely, in pediatric coronary microvessels, Dox-induced impairment of FMD was significantly reduced in comparison with adult subjects. In both adult and pediatric coronary microvessels, ACh-induced constriction was reversed into dilation in the presence of Dox. Smooth muscle-dependent dilation remained unchanged in all groups tested. In vessels from adult subjects, acute treatment with Dox in clinically relevant doses caused significant impairment of coronary arteriolar function, whereas vessels from pediatric subjects showed only marginal impairment to the same stressor. This interesting finding might explain the delayed onset of future adverse CV events in children compared with adults after anthracycline therapy.NEW & NOTEWORTHY We have characterized, for the first time, human microvascular responses to acute ex vivo exposure to doxorubicin in coronary vessels from patients without cancer. Our data show an augmented impairment of endothelial function in vessels from adult subjects compared with pediatric samples.

Cancer therapy-induced cardiovascular toxicity: old/new problems and old drugs

Cardio-oncology has emerged as an exciting new field at the intersection of cardiology and oncology. While improved oncology treatment efficacy has increased survival rates in cancer patients, the long-term cardiovascular consequences of this life-saving treatment have become more clinically relevant. Both traditional and newer (targeted) cancer therapies can have cardiovascular and metabolic sequelae, resulting in heart failure, coronary artery disease, myocarditis, pericardial disease, hypertension, and vascular and metabolic perturbations (Moslehi JJ. Cardiovascular toxic effects of targeted cancer therapies. N Engl J Med 375: 1457-1467, 2016). Both acute and chronic cardiovascular toxicities have proven challenging for clinicians and patients, significantly contributing to morbidity and mortality. Although chronic cardiovascular disease affects a growing number of cancer survivors (~17 million in the United States in 2019), cardiovascular toxicities associated with cancer and cancer therapies are poorly understood mechanistically. To balance potential damage to the cardiovascular system with effective and efficient cancer treatment, novel strategies are sorely needed. This perspective focuses on an assembly of articles that discuss novel means of counteracting adverse cardiovascular events in response to anticancer therapy. In light of new clinical syndromes in cardiology due to cancer therapies, we hope to highlight promising research opportunities offered by cardio-oncology (Bellinger AM, Arteaga CL, Force T, Humphreys BD, Demetri GD, Druker BJ, Moslehi JJ. Cardio-oncology: how new targeted cancer therapies and precision medicine can inform cardiovascular discovery. Circulation 132: 2248-2258, 2015.).