Early Diastolic Dysfunction after Cancer Chemotherapy: Primary Endpoint Results of a Multicenter Cardio-Oncology Study

Assessment of Specific Biomarkers' Profile and Structural, Functional Parameters of the Left Ventricle in Patients With Lymphomas Undergoing Antitumor Therapy

AIM

To evaluate the dynamics of specific biomarkers for cardiotoxicity, endothelial dysfunction, fibrosis, systemic inflammation, and morpho-functional alterations in the left ventricular (LV) myocardium in patients with newly diagnosed lymphomas during 6 courses of polychemotherapy (PCT).

MATERIAL AND METHODS

The study included 30 patients with newly diagnosed lymphomas. All patients were evaluated for laboratory markers of cardiotoxicity at baseline and after 6 courses of chemotherapy (6 months), including N-terminal pro-brain natriuretic peptide (NT-proBNP), high-sensitivity troponin I (hsTnI), endothelin-1 (ET-1), circulating cardiac biomarker ST-2, high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), and LV structural and functional echocardiographic (EchoCG) parameters.

RESULTS

The changes in NT-proBNP and hsTnI concentrations during 6 courses of PCT were not statistically significant. Comparison of the baseline values with those after 6 courses of PCT showed increases in the median concentrations of ET-1 (3.38 and 5.5 pg/ml, respectively; p=0.438) and ST-2 (12.21 and 26.75 ng/ml, respectively; p=0.687). Markers of systemic inflammation were significantly decreased after 6 courses of PCT: the median CRP decreased from 15.2 to 0.72 mg/ml (p=0.006), and the median IL-6 decreased from 12.2 to 5.1 pg/ml (p=0.034). EchoCG data revealed a statistically significant impairment of the LV diastolic function parameters (E/A; E/e' lateral; E/e' average; left atrial volume index; isovolumic relaxation time). A moderate direct correlation was found between the ET-1 concentration and the isovolumic relaxation time at baseline and after 6 courses of PCT, respectively (r1 = 0.387, p=0.047 and r2 = 0.391, p=0.035). No changes in the LV systolic function were observed.

CONCLUSION

The study showed that patients with lymphoproliferative diseases had no signs of cardiotoxicity during PCT according to the accepted criteria. This study described and highlighted for the first time the interrelation of endothelial dysfunction, profibrotic status, and LV diastolic dysfunction as manifestations of cardiovascular toxicity in patients with lymphoproliferative diseases. It is advisable to supplement the integrated strategies for the prevention and monitoring of PCT cardiovascular toxicity with a thorough evaluation of instrumental parameters of diastolic dysfunction for timely initiation/correction of cardioprotective therapy.

Anthracyclines, Diastolic Dysfunction and the road to Heart Failure in Cancer survivors: An untold story

Many cardiovascular diseases are characterized by diastolic dysfunction, which associates with worse clinical outcomes like overall mortality and hospitalization for heart failure (HF). Diastolic dysfunction has also been suspected to represent an early manifestation of cardiotoxicity induced by cancer drugs, with most of the information deriving from patients treated with anthracyclines; however, the prognostic implications of diastolic dysfunction in the anthracycline-treated patient have remained poorly explored or neglected. Here the molecular, pathophysiologic and diagnostic aspects of anthracycline-related diastolic dysfunction are reviewed in the light of HF incidence and phenotype in cancer survivors. We describe that the trajectories of diastolic dysfunction toward HF are influenced by a constellation of patient- or treatment- related factors, such as comorbidities and exposure to other cardiotoxic drugs or treatments, but also by prospective novel opportunities to treat diastolic dysfunction. The importance of a research-oriented multidimensional approach to patient surveillance or treatment is discussed within the framework of what appears to be a distinct pathophysiologic entity that develops early during anthracycline treatment and gradually worsens over the years.

Left ventricular diastolic function and cardiotoxic chemotherapy

BACKGROUND

Left ventricular ejection fraction falls when the myocardium has already lost a significant portion of its functional capacity. There are conflicting data on whether diastolic dysfunction precedes systolic dysfunction after cardiotoxic chemotherapy. We aimed to study systolic and diastolic dysfunction after cardiotoxic chemotherapy and whether diastolic dysfunction can predict subsequent risk of systolic dysfunction. It was an observational prospective cohort study, and patients receiving cardiotoxic chemotherapy were included. Baseline, demographic, and clinical details were recorded. Echocardiographic measurements of left ventricular systolic function, global longitudinal strain, and diastolic function were noted at baseline, three months, and 6 months.

RESULTS

We included eighty patients. The mean age of the patients was 54.92 ± 7.6 years, predominantly females (80%). The mean left ventricular ejection fraction fell from 64.92 ± 1.96 to 60.97 ± 4.94 at 6 months. Low ejection fraction was seen in 8 (10%) patients at 6 months. The mean global longitudinal strain (GLS) at baseline was - 18.81 ± 0.797 and fell to - 17.65 ± 2.057 at 6 months, with 12 (15%) patients having low GLS (< - 18). Grade 1 diastolic dysfunction was seen in 22 (27.5%) patients, and grade 2 diastolic dysfunction was seen in 3 (3.8%) patients at 6 months. There was a significant decrease in E/A ratio (inflow early diastolic velocity/Inflow late diastolic velocity), mitral tissue Doppler velocity, and an increase in isovolumic relaxation time, mitral valve deceleration time, and E/e' (inflow early diastolic velocity/tissue Doppler mitral annular velocity), at three months and 6 months. Ejection fraction at 6 months was significantly and negatively correlated with diastolic dysfunction at three months (r = - 0.595, p = 0.02).

CONCLUSIONS

Cardiotoxic chemotherapy is associated with early diastolic dysfunction. Early diastolic dysfunction predicts subsequent left ventricular systolic dysfunction.

Effects of Physical Activity on Cardiotoxicity and Cardio respiratory Function in Cancer Survivors Undergoing Chemotherapy: A Systematic Review and Meta-Analysis

Introduction: Physical activity, as a promising complementary therapy, has shown considerable potential for reducing chemotherapy-related cardiotoxicity (CTRCT) and enhancing cardiorespiratory function (CRF). This study aimed to systematically assess the effects of physical activity on CTRCT and CRF in various cancer survivors receiving chemotherapy. Methods: A systematic review and meta-analysis was conducted. A literature search was conducted across 8 databases from inception to January 2024 and was limited to the English and Chinese languages. Statistical analysis was conducted using RevMan 5.3 and Stata 17.0 software. Results: Sixteen randomized controlled trials (RCTs) were included in the systematic review and 15 RCTs were included in the meta-analysis. Among various cancer survivors undergoing chemotherapy, physical activity markedly increased absolute oxygen uptake (VO2peak or VO2max; WMD = 292.99, 95% confidence interval [CI]:87.87 to 498.12, P = .005), with significant effects of subgroup analysis at 4 to 10 weeks (P = .02) or over 16 weeks (P < .01), moderate-to-high or high intensity training (both P < .0001), patients with breast cancer (P = .009) and reported CTRCT (P = .007); relative VO2peak or VO2max(WMD = 3.30, 95%CI: 2.02 to 4.58, P < .00001), with significant effects of subgroup analysis at 10 to 16 weeks or over 16 weeks, moderate-to-high or high intensity training, patients with breast cancer, with or without reported CTRCT and exercise during chemotherapy (all P < .01); E/A values (WMD = 0.11, 95%CI:0.03 to 0.18, P = .007) and flow-mediated dilatation (WMD = 2.71, 95%CI:1.49 to 3.94, P < .0001). Compared to the control group, physical activity had no significant improvement in E/e' values (P = .50), NT-proBNP (P = .12), hs-cTn (P = 3.83), left ventricular ejection fraction (WMD = 2.89, 95%CI: -3.28 to 9.06, P = .36) with non-significant effects being independent of exercise intensity or duration, with or without CTRCT and cancer types (all P > .05), and global longitudinal strain (WMD = 0.37, 95%CI: -0.20 to 0.94, P = .20) with non-significant effects being independent of exercise duration and cancer types(both P > .05). Conclusions: Physical activity may be an effective complementary therapy to improve CRF and CTRCT in various cancer survivors, particularly during medium to long duration and moderate-to-high and high intensity exercise with concurrent chemotherapy.

Diastolic function assessment with left atrial strain in long-term survivors of childhood acute lymphoblastic leukemia

INTRODUCTION AND OBJECTIVES

Survivors of childhood cancer might be at increased risk of diastolic dysfunction at follow-up due to exposure to cardiotoxic treatment. Although assessment of diastolic function is challenging in this relatively young population, left atrial strain might provide a novel insight in this evaluation. Our aim was to examine diastolic function in a cohort of long-term survivors of childhood acute lymphoblastic leukemia by using left atrial strain and conventional echocardiographic parameters.

METHODS

Long-term survivors who were diagnosed at a single center between 1985 and 2015 and a control group of healthy siblings were recruited. Conventional diastolic function parameters and atrial strain were compared, and the latter was measured during the 3 atrial phases: reservoir (PALS), conduit (LACS) and contraction (PACS). Inverse probability of treatment weighting was used to account for differences between the groups.

RESULTS

We analyzed 90 survivors (age, 24.6±9.7 years, time since diagnosis 18 [11-26] years) and 58 controls. PALS and LACS were significantly reduced compared with the control group: 46.4±11.2 vs 52.1±11.7; P=.003 and 32.5±8.8 vs 38.2±9.3; P=.003, respectively. Conventional diastolic parameters and PACS were similar between the groups. The reductions in PALS and LACS were associated with exposure to cardiotoxic treatment in age- and sex-adjusted analysis (≥ moderate risk, low risk, controls): 45.4±10.5, 49.5±12.9, 52.1±11.7; Padj=.003, and 31.7±9.0, 35.2±7.5, 38.2±9.3; Padj=.001, respectively.

CONCLUSIONS

Long-term childhood leukemia survivors showed a subtle impairment of diastolic function that was detected with atrial strain but not with conventional measurements. This impairment was more pronounced in those with higher exposure to cardiotoxic treatment.

Initial Phase of Anthracycline Cardiotoxicity Involves Cardiac Fibroblasts Activation and Metabolic Switch

The application of doxorubicin (DOX) is hampered by cardiotoxicity, with diastolic dysfunction as the earliest manifestation. Fibrosis leads to impaired relaxation, but the mechanisms that operate shortly after DOX exposure are not clear. We asked whether the activation of cardiac fibroblasts (CFs) anticipates myocardial dysfunction and evaluated the effects of DOX on CF metabolism. CFs were isolated from the hearts of rats after the first injection of DOX. In another experiment, CFs were exposed to DOX in vitro. Cell phenotype and metabolism were determined. Early effects of DOX consisted of diastolic dysfunction and unchanged ejection fraction. Markers of pro-fibrotic remodeling and evidence of CF transformation were present immediately after treatment completion. Oxygen consumption rate and extracellular acidification revealed an increased metabolic activity of CFs and a switch to glycolytic energy production. These effects were consistent in CFs isolated from the hearts of DOX-treated animals and in naïve CFs exposed to DOX in vitro. The metabolic switch was paralleled with the phenotype change of CFs that upregulated markers of myofibroblast differentiation and the activation of pro-fibrotic signaling. In conclusion, the metabolic switch and activation of CFs anticipate DOX-induced damage and represent a novel target in the early phase of anthracycline cardiomyopathy.

Cardiac Imaging in Childhood Cancer Survivors: A State-of-the-Art Review

Childhood cancer survival has improved significantly in the past few decades, reaching rates of 80% or more at 5 years. However, with improved survival, early- and late-occurring complications of chemotherapy and radiotherapy exposure are becoming progressively more evident. Cardiovascular diseases represent the leading cause of non-oncological morbidity and mortality in this highly vulnerable population. Therefore, the necessity of reliable, noninvasive screening tools able to early identify cardiac complications early is now pre-eminent in order to implement prevention strategies and mitigate disease progression. Echocardiography, may allow identification of myocardial dysfunction, pericardial complications, and valvular heart diseases. However, additional imaging modalities may be necessary in selected cases. This manuscript provides an in-depth review of noninvasive imaging parameters studied in childhood cancer survivors. Furthermore, we will illustrate brief surveillance recommendations according to available evidence and future perspectives in this expanding field.

Reduced cardiovascular reserve capacity in long-term allogeneic stem cell transplant survivors

Premature cardiovascular mortality is increased in long-term allogeneic stem cell transplant (allo-SCT) survivors, but little information exists regarding subclinical cardiovascular dysfunction in this population. We compared peak oxygen uptake ([Formula: see text]O_2peak), a prognostic cardiovascular marker, and its determinants between long-term allo-SCT survivors and non-cancer controls. Fourteen allo-SCT survivors (mean ± SD, 44 ± 15 years, 50% male, median time since allo-SCT: 6.5 years [range 2-20]) and 14 age- and sex-matched controls (46 ± 13 years, 50% male) underwent cardiopulmonary exercise testing to quantify [Formula: see text]O_2peak. Resting echocardiography (left-ventricular ejection fraction and strain), exercise cardiac MRI (peak cardiac and stroke volume index [CI_peak, SVI_peak]), biochemistry (hemoglobin, troponin-I, B-natriuretic peptide), dual-energy x-ray absorptiometry (lean [LM] and fat [FM] mass, percent body fat [%BF]) and Fick-principal calculation (arteriovenous oxygen difference) were also performed. Survivors exhibited impaired [Formula: see text]O_2peak as compared with controls (25.9 ± 5.1 vs. 33.7 ± 6.5 ml kg^-1 min^-1, p = 0.002), which coincided with reduced CI_peak (6.6 ± 0.8 vs. 8.6 ± 1.9 L min^-1 m^-2; p = 0.001) secondary to reduced SVI_peak (48 ± 4 vs. 61 ± 8 ml m^-2; p < 0.001) rather than chronotropic impairment, and higher %BF (difference, 7.9%, p = 0.007) due to greater FM (5.8 kg; p = 0.069) and lower LM (4.3 kg, p = 0.25). All other measures were similar between groups. Despite comparable resting cardiac function and biomarker profiles, survivors exhibited reduced [Formula: see text]O_2peak and exercise cardiac function and increased %BF relative to controls. These results highlight potential therapeutic avenues and the utility of exercise-based cardiovascular assessment in unmasking cardiovascular dysfunction in allo-SCT survivors.

Beyond hypertension: Diastolic dysfunction associated with cancer treatment in the era of cardio-oncology

Cancer patients are at an increased risk of cardiovascular events. Both old-generation cytostatics/cytotoxics and new-generation "targeted" drugs can in fact damage cardiomyocytes, endothelial cells of veins and arteries, specialized cells of the conduction system, pericardium, and valves. A new discipline, cardio-oncology, has therefore developed with the aim of protecting cancer patients from cardiovascular events, while also providing them with the best possible oncologic treatment. Anthracyclines have long been known to elicit cardiotoxicity that, depending on treatment- or patient-related factors, may progress with a variable velocity toward cardiomyopathy and systolic heart failure. However, early compromise of diastolic function may precede systolic dysfunction, and a progression of early diastolic dysfunction to diastolic rather than systolic heart failure has been documented in long-term cancer survivors. This chapter first describes general notions about hypertension in the cancer patient and then moves on reviewing the pathophysiology and clinical trajectories of diastolic dysfunction, and the molecular mechanisms of anthracycline-induced diastolic dysfunction. Diastolic dysfunction can in fact be caused and/or aggravated by hypertension. Pharmacologic foundations and therapeutic opportunities to prevent or treat diastolic dysfunction before it progresses toward heart failure are also reviewed, with a special emphasis on the mechanisms of action of drugs that raised hopes to treat diastolic dysfunction in the general population (sacubitril/valsartan, guanylyl cyclase activators, phosphodiesterase inhibitors, ranolazine, inhibitors of type-2 sodium-glucose-inked transporter). Cardio-oncologists will be confronted with the risk:benefit ratio of using these drugs in the cancer patient.

Circulating biomarkers for management of cancer therapeutics related cardiac dysfunction

Cancer therapeutics related cardiac dysfunction (CTRCD) has emerged as a major cause of morbidity and mortality in cancer survivors. Effective clinical management of CTRCD is impeded by a lack of sensitive diagnostic and prognostic strategies. Circulating molecular markers could potentially address this need as they are often indicative of cardiac stress before cardiac damage can be detected clinically. A growing understanding of the underlying physiological mechanisms for CTRCD has inspired research efforts to identify novel pathophysiologically-relevant biomarkers that may also guide development of cardio-protective therapeutic approaches. The purpose of this review is to evaluate current circulating biomarkers of cardiac stress and their potential role in diagnosis and management of CTRCD. We also discuss some emerging avenues for CTRCD-focused biomarker investigations.

Importance of cardio-oncology. How to detect suclinical heart failure

Today one of the main causes of mortality is cancer. Survival in cancer patients has increased from 1970 (25%) to the present (80%). Following the introduction of anthracyclines as a cancer treatment since 1960-70, more than 60% of patients are treated with these agents, although chemotherapeutic exposure leads to cardiovascular diseases as the main cause of mortality in surviving patients. of cancer in the 21st Century. There are multiple factors that increase the sensitivity of anthracyclic-induced cardiotoxicity. In 1970 the gold standard for the detection of ventricular dysfunction was endomyocardial biopsy, subsequently the detection and management of cardiotoxicity was guided by symptoms, in 1981 the detection of cardiotoxicity was reported with the determination of the ejection fraction of the left ventricle (LVEF), by 2D echocardiography. Currently, the 3D echocardiogram for LVEF and systolic and diastolic volumes have presented a high correlation of the values obtained by magnetic resonance imaging for the evaluation of cardiac function. Today strain, strain-rate and speckle tracking echocardiography are used to determine regional and global myocardial function. For a comprehensive assessment, these results can be complemented with cardiac biomarkers (troponins) and electrocardiographic changes. In this way, subclinical heart failure can be detected and timely treatment can be given.

Comprehensive Assessment of Changes in Left Ventricular Diastolic Function With Contemporary Breast Cancer Therapy

OBJECTIVES

This study determined the effects of doxorubicin and/or trastuzumab on diastolic function and the relationship between diastolic function and systolic dysfunction.

BACKGROUND

Doxorubicin and trastuzumab can result in left ventricular ejection fraction (LVEF) declines. However, the effects of these therapies on diastolic function remain incompletely defined.

METHODS

In a rigorously phenotyped, longitudinal cohort study of 362 breast cancer participants treated with doxorubicin, doxorubicin followed by trastuzumab, or trastuzumab alone, changes in diastolic function were evaluated using linear models estimated via generalized estimating equations. Associations between baseline and changes in diastolic function with LVEF and longitudinal strain were also determined using generalized estimating equations. The Kaplan-Meier estimator derived the proportion of participants who experienced incident diastolic dysfunction. Cox proportional hazards models estimated the associations between participant characteristics and diastolic dysfunction risk, and between diastolic function and cancer therapy-related cardiac dysfunction risk, defined by an LVEF decline of ≥10% to <50%.

RESULTS

Over a median of 2.1 years (interquartile range [IQR]: 1.3 to 4.2 years), participants treated with doxorubicin or doxorubicin followed by trastuzumab demonstrated a persistent worsening in diastolic function, with reductions in the E/A ratio, lateral and septal e' velocities, and increases in E/e' (p < 0.01). These changes were not observed with trastuzumab alone. Incident abnormal diastolic function grade occurred in 60% at 1 year, 70% by 2 years, and 80% by 3 years. Abnormal diastolic function grade was associated with a subsequent decrease in LVEF (-2.1%; 95% confidence intervals [CI]: -3.1 to -1.2; p < 0.001) and worsening in longitudinal strain (0.6%; 95% CI: 0.1 to 1.1; p = 0.013) over time. Changes in E/e' ratio were modestly associated with worsening longitudinal strain (0.1%; 95% CI: 0.0 to 0.2; p = 0.022).

CONCLUSIONS

A modest, persistent worsening of diastolic function is observed with contemporary breast cancer therapy. Abnormal and worsening diastolic dysfunction is associated with a small risk of subsequent systolic dysfunction. (Cardiotoxicity of Cancer Therapy [CCT]; NCT01173341).

Cardio-oncology in clinical studies and real life

Session V of the Colloquium was chaired by Professors Teresa López-Fernández of Spain and Grzegorz Opolski of Poland. The 3 speakers addressed cardio-oncology issues as they relate to both clinical studies and real life situations. Professor Susan Dent discussed cardio-oncology networks for patients, emphasizing the importance of establishing a framework where the expertise of the cardiology consultant can supplement and reinforce the goals of optimal cancer therapy. Professor Thomas Suter moved the discussion further, sharing his insight into cardiac monitoring in clinical trials, emphasizing the lack of uniform criteria and lack of consensus regarding reversibility of cardiac events and long-term implications of modest declines in systolic function frequently found in clinical trials for which long-term follow-up may not be a component of the trial. Professor Giorgio Minotti added important considerations to the discussion of clinical trials. He emphasized that the usual reporting of cardiac systolic function omits important diastolic dysfunction data generated but often ignored during the routine cardiac exams. The inclusion of cardiac biomarker changes would also help to broaden the perspective of cardiac effects and events seen in patients enrolled in clinical trials.

Pharmacology of Ranolazine versus Common Cardiovascular Drugs in Patients with Early Diastolic Dysfunction Induced by Anthracyclines or Nonanthracycline Chemotherapeutics: A Phase 2b Minitrial

We have reported that anthracyclines and nonanthracycline chemotherapeutics caused diastolic dysfunction in cancer patients without cardiovascular risk factors. Diastolic dysfunction occurred as early as 1 week after the last chemotherapy cycle and manifested as impaired myocardial relaxation at echocardiography or persistent elevations of B-type natriuretic peptide (BNP) or troponin. The antianginal drug ranolazine shows cardiac relaxant effects that we considered of value to treat early diastolic dysfunction induced by cancer drugs; therefore, 24 low-risk patients with post-chemotherapy diastolic dysfunction were randomized (1:1) to ranolazine or the investigator's choice of common cardiovascular drugs, such as β-blockers and/or angiotensin-converting enzyme inhibitors or loop diuretics (best standard therapy, BST). After 5 weeks, 12 of 12 patients on ranolazine recovered from diastolic dysfunction, whereas 3 of 12 patients on BST did not improve; however, adverse events (not serious) were apparently more frequent for ranolazine than for BST (4/12 vs. 1/12). Ranolazine did not lower blood pressure, whereas BST reduced systolic pressure and caused a trend toward a reduced diastolic pressure. Most patients at randomization showed tachycardia resulting from chemotherapy-related anemia. Hemoglobin recovery contributed to normalizing heart rate in these patients; however, some patients in the ranolazine arm developed tachycardia through chronotropic effects of high BNP levels and returned to a normal heart rate through the effects of ranolazine on decreasing BNP levels. This minitrial describes the potential effects of ranolazine on relieving chemotherapy-related diastolic dysfunction; however, clinical implications of these findings need to be characterized by studies with an adequate sample size. SIGNIFICANCE STATEMENT: The antianginal drug ranolazine causes cardiac relaxant effects that might relieve diastolic dysfunction. In a clinical pharmacology study, 24 patients were randomized (1:1) to receive ranolazine or common cardiovascular drugs to treat early diastolic dysfunction induced by anthracycline-based or nonanthracycline chemotherapy. Ranolazine relieved diastolic dysfunction in these patients. The safety profile of ranolazine in cancer patients is similar to that of the general population. Compared with common cardiovascular drugs, ranolazine relieved diastolic dysfunction without lowering blood pressure. The sample size of this study was nonetheless too small to permit considerations about the potential clinical value of ranolazine for oncologic patients with early diastolic dysfunction induced by anthracyclines or nonanthracycline chemotherapeutics. This information should be obtained by studies with an adequate sample size.

Ivabradine in Cancer Treatment-Related Left Ventricular Dysfunction

BACKGROUND

Patients developing cancer treatment-related left ventricular dysfunction (CTrLVD) require a prompt therapy. Hypotension, dizziness, and fatigue often limit the use of angiotensin-converting enzyme inhibitors (ACEi), angiotensin receptor blockers (ARB), and β-blockers (BB) in cancer patients who may already be afflicted by these symptoms. Ivabradine is a heart rate-lowering drug that does not cause hypotension and may be used in heart failure with reduced left ventricular ejection fraction (LVEF).

OBJECTIVE

The aim of this paper was to investigate the role of ivabradine to treat CTrLVD.

METHODS

A retrospective analysis in a cohort of 30 patients with CTrLVD (LVEF < 50%) receiving ivabradine on top of the maximal tolerated dose of ACEi/ARB and BB was performed. We evaluated cardiovascular treatment, oncologic treatment, LVEF, functional class (New York Heart Association [NYHA]), and fatigue during the study period.

RESULTS

Ivabradine was initially started at the dose of 2.5 mg/b.i.d. in most patients and then carefully titrated. Hypotension (70%) and fatigue (77%) were the main causes limiting the treatment with ACEi/ARB and BB. After a mean follow-up of 6.5 months, LVEF increased from 45.1% (SD = 6.4) to 53.2% (SD = 3.9; p < 0.001). When patients were analyzed according to the type of cancer therapy, no difference in LVEF changes across the groups was found. NYHA class ameliorated in 11 patients, while fatigue improved in 8 patients. No serious cardiovascular side effects were reported.

CONCLUSIONS

The ability to improve symptoms and LVEF in unfit cancer patients makes ivabradine a reasonable pharmacological tool for treating CTrLVD.

The Endogenous Lusitropic and Chronotropic Agent, B-Type Natriuretic Peptide, Limits Cardiac Troponin Release in Cancer Patients with an Early Impairment of Myocardial Relaxation Induced by Anthracyclines

We have reported that cancer patients treated with anthracycline-based or nonanthracycline chemotherapy developed an early impairment of myocardial relaxation at echocardiography or persistent elevations of the cardiac hormone B-type natriuretic peptide (BNP). Post-hoc pharmacologic analyses showed that BNP elevations were induced by impaired relaxation and caused positive lusitropic effects that maintained normal relaxation. High BNP levels and impaired relaxation were therefore characterized as mutually exclusive manifestations of diastolic dysfunction, but high BNP levels resulted in positive chronotropism and inappropriate tachycardia. Some patients developed increased circulating levels of cardiac troponin I isoform (cTnI), a marker of cardiomyocyte necrosis. Here we have characterized whether cTnI elevations correlated with diastolic dysfunction that manifested as impaired relaxation or a high level of BNP. The effects of high BNP levels on cTnI elevations were also characterized. We show that impaired relaxation or high BNP levels were significantly more frequent in patients with cTnI elevations. High BNP levels diminished the plasma peak and area under the curve of cTnI, but this result was accompanied by inappropriate tachycardia. cTnI elevations occurred only in patients treated with anthracyclines; moreover, the association of impaired relaxation or high BNP levels with cTnI elevations was significantly more frequent in doxorubicin-treated patients compared with patients treated with its analog, epirubicin. These findings describe cause-and-effect relations between impaired relaxation and cardiomyocyte necrosis, illuminate the role of anthracycline analogs, denote that the beneficial effects of BNP in relieving impaired relaxation and cardiomyocyte necrosis are counterbalanced by inappropriate tachycardia. Patients showing troponin elevations and impaired relaxation or high BNP levels should be treated with lusitropic drugs that lack a positive chronotropism.