Endothelial Function in Patients with Hematologic Malignancies Undergoing High-Dose Chemotherapy Followed by Hematopoietic Stem Cell Transplantation

Rapid cardiovascular aging following allogeneic hematopoietic cell transplantation for hematological malignancy

Introduction

Allogeneic hematopoietic cell transplantation (allo-HCT) offers a potential cure for high-risk hematological malignancy; however, long-term survivors experience increased cardiovascular morbidity and mortality. It is unclear how allo-HCT impacts cardiovascular function in the short-term. Thus, this 3-month prospective study sought to evaluate the short-term cardiovascular impact of allo-HCT in hematological cancer patients, compared to an age-matched non-cancer control group.

Methods

Before and ~3-months following allo-HCT, 17 hematological cancer patients (45 ± 18 years) underwent cardiopulmonary exercise testing to quantify peak oxygen uptake (VO₂peak)-a measure of integrative cardiovascular function. Then, to determine the degree to which changes in VO₂peak are mediated by cardiac vs. non-cardiac factors, participants underwent exercise cardiac MRI (cardiac reserve), resting echocardiography (left-ventricular ejection fraction [LVEF], global longitudinal strain [GLS]), dual-energy x-ray absorptiometry (lean [LM] and fat mass [FM]), blood pressure (BP) assessment, hemoglobin sampling, and arteriovenous oxygen difference (a-vO₂diff) estimation via the Fick equation. Twelve controls (43 ± 13 years) underwent identical testing at equivalent baseline and 3-month time intervals.

Results

Significant group-by-time interactions were observed for absolute VO₂peak (p = 0.006), bodyweight-indexed VO₂peak (p = 0.015), LM (p = 0.001) and cardiac reserve (p = 0.019), which were driven by 26, 24, 6, and 26% reductions in the allo-HCT group (all p ≤ 0.001), respectively, as no significant changes were observed in the age-matched control group. No significant group-by-time interactions were observed for LVEF, GLS, FM, hemoglobin, BP or a-vO₂diff, though a-vO₂diff declined 12% in allo-HCT (p = 0.028).

Conclusion

In summary, allo-HCT severely impairs VO₂peak, reflecting central and peripheral dysfunction. These results indicate allo-HCT rapidly accelerates cardiovascular aging and reinforces the need for early preventive cardiovascular intervention in this high-risk group.

A non-interventional study of microcirculation dynamics in allogeneic hematopoietic cell transplantation survivors compared to controls: evidence of impaired microvascular response regardless of conventional cardiovascular risk factors

Allogeneic hematopoietic cell transplantation (alloHCT) survivors have been recently recognized as patients at increased cardiovascular risk. We hypothesized that vascular function remains impaired in alloHCT survivors free of graft-versus-host-disease or relapse. We enrolled consecutive adult alloHCT survivors and non-HCT control individuals (January 2019-March 2020), matched for traditional cardiovascular risk factors. Microvascular dysfunction was dynamically assessed in real time by Laser Speckle Contrast Analysis (LASCA). Carotid-femoral pulse-wave velocity (PWV) and carotid intima media thickness (IMT) were assessed as surrogate markers of cardiovascular disease. We studied 75 patients after a median of 3.2 (range 2.1-4.9) years from alloHCT, who had suffered from grade 2 to 3 acute (20%) and/or moderate/severe chronic GVHD (42%), and 75 controls. Although traditional cardiovascular risk factors and surrogate markers of cardiovascular disease did not differ between groups, alloHCT survivors showed significantly impaired microvascular function (baseline and peak flux, time to peak, base to peak and base to occlusion change). LASCA indices were also independently associated with alloHCT. Our study shows for the first-time impaired microcirculation dynamics in alloHCT survivors, independently of cardiovascular risk factors. Additional studies are needed to address the role of novel markers in cardiovascular risk prediction, along with effects of disease type, phase, and pre-transplant treatments.

Assessment of Endothelial Injury and Pro-Coagulant Activity Using Circulating Microvesicles in Survivors of Allogeneic Hematopoietic Cell Transplantation

(1) Background: survivors of allogeneic hematopoietic cell transplantation (alloHCT) suffer from morbidity and mortality due to cardiovascular events. We hypothesized that vascular injury and pro-coagulant activity are evident in alloHCT survivors without existing alloHCT complications or relapse. (2) Methods: we enrolled consecutive adult alloHCT survivors without established cardiovascular disease and control individuals matched for traditional cardiovascular risk factors (January-December 2019). Circulating microvesicles (MVs) of different cellular origins (platelet, erythrocyte, and endothelial) were measured by a standardized flow cytometry protocol as novel markers of vascular injury and pro-coagulant activity. (3) Results: we recruited 45 survivors after a median of 2.3 (range 1.1-13.2) years from alloHCT, and 45 controls. The majority of patients suffered from acute (44%) and/or chronic (66%) graft-versus-host disease (GVHD). Although the two groups were matched for traditional cardiovascular risk factors, alloHCT survivors showed significantly increased platelet and erythrocyte MVs compared to controls. Within alloHCT survivors, erythrocyte MVs were significantly increased in patients with a previous history of thrombotic microangiopathy. Interestingly, endothelial MVs were significantly increased only in alloHCT recipients of a myeloablative conditioning. Furthermore, MVs of different origins showed a positive association with each other. (4) Conclusions: endothelial dysfunction and increased thrombotic risk are evident in alloHCT recipients long after alloHCT, independently of traditional cardiovascular risk factors. An apparent synergism of these pathophysiological processes may be strongly involved in the subsequent establishment of cardiovascular disease.

Early Prediction of Cardiovascular Risk after Hematopoietic Cell Transplantation: Are We There Yet?

Cardiovascular (CV) events have emerged as a major cause of morbidity and mortality among hematopoietic cell transplantation (HCT) survivors. Accumulating evidence supports the presence of increased CV risk in HCT recipients. Most studies have focused mainly on traditional CV risk factors, such as the metabolic syndrome and hypertension. However, detection of these factors suggests the development of irreversible overt clinical atherosclerosis. Therefore, earlier prediction of CV risk is needed to prevent CV morbidity and mortality in these patients. In the field of CV research, endothelial dysfunction is considered an early event in the pathophysiology of CV risk factors, and a number of markers have been proposed for its assessment. In addition, markers of subclinical target organ damage have been introduced to implement CV risk prediction and early preventive or intensive therapeutic interventions. Furthermore, a number of CV models have been suggested aiming for optimal stratification of patients. Preliminary studies have indicated excess CV risk using these early markers in HCT recipients. However, their role in the pathophysiology and clinical practice in HCT survivors remains largely understudied. Taking into account the need for increased awareness from treating physicians in this evolving setting, we conducted a state-of-the-art review aiming to summarize current knowledge on endothelial dysfunction, subclinical target organ damage, and CV risk prediction in HCT survivors.

Exercise training improves vascular function and secondary health measures in survivors of pediatric oncology related cerebral insult

Adolescent and young adult (AYA) survivors of pediatric oncology related cerebral insult are vulnerable to numerous treatment-induced deficits that significantly enhance cardiovascular disease risk. Regular exercise improves endothelial function, fitness, body composition and musculoskeletal function which may reduce predisposition for cardiovascular disease. Here we assessed the feasibility and effectiveness of a 24-week exercise intervention on cardiovascular, physical and metabolic outcomes in this population. Thirteen survivors (6 male, 7 female; median age 19 y (range 16-23 y) were recruited to participate in a 48-week study consisting of a 24-week control period (regular care) followed by a 24-week exercise intervention. Outcome measures were collected at entry (week 0) and following regular care (24-week) and exercise (48-week). Assessed variables included endothelial function (flow mediated dilation, FMD), blood pressure, heart rate (HR), aerobic capacity, anthropometry, body composition, muscular strength (3 repetition maximum testing), muscular endurance (repetitions/min) and physical activity levels (accelerometry). Compared to baseline, delta diameter (p = 0.008) and FMD (p = 0.029) of the brachial artery increased following exercise. Bicep-curl strength also increased following exercise compared to baseline (p = 0.019), while submaximal (6 min mark) measures of ventilation (p = 0.012), rating of perceived exertion (p = 0.012), HR (p = 0.001), absolute (p = 0.000) and relative (p = 0.000) aerobic capacity decreased. Breaks in sedentary time increased (p = 0.043) following exercise compared to regular care. Although the sample was small and heterogeneous, this study demonstrates that exercise is achievable and has positive effects on vascular function, submaximal fitness, local strength and physical activity in a population of AYA survivors of pediatric oncology related cerebral insult.

Arterial stiffness in hematologic malignancies

Malignant and cardiovascular disorders are the top causes of mortality worldwide. This article reviews the main literature data and mechanisms linking hematologic malignancies and arterial stiffness, focusing on recent experimental and clinical results. Several links were found in hematologic malignancies between complete blood count and arterial stiffness. Chemotherapy, especially anthracyclines, cyclophosphamide and tyrosine kinase inhibitors, as well as radiotherapy and hematopoietic stem cell transplantation are the main known causes of arterial stiffness increase in hematologic malignancies. The mechanisms of arterial stiffness elevation in hematologic malignancies include an increased oxidative stress, impaired vascular wall homeostasis, endothelial dysfunction and apoptosis of endothelial cells, overexpression of inflammatory cytokines, accelerated atherosclerosis, increased blood viscosity and unstable platelet aggregates. Guidelines regarding cardiovascular health screening and cardiovascular risk scores are necessary for hematologic cancer survivors in order to improve prognosis and quality of life of the patients.