Predictors of steroid-refractory immune checkpoint inhibitor associated myocarditis

Background/Introduction

Immune checkpoint inhibitor (ICI)-associated myocarditis has a high mortality rate of approximately 50%. Clinical decompensation often occurs despite first-line treatment with corticosteroids. Factors associated with steroid failure are currently unknown.

Purpose

To identify predictors of steroid failure in patients with ICI-associated myocarditis.

Methods

We developed a web-based registry to collect and study 157 cases with clinical manifestations of ICI-associated myocarditis across 16 countries. Steroid failure was defined as patients who were escalated to immunomodulators after ≥1mg/kg daily dose of prednisone or had in-hospital death due to myocarditis despite ≥1mg/kg daily dose of prednisone. Steroid response was defined as all other patients treated with steroids without escalation to immunomodulators and without death due to myocarditis. A multivariate logistic model accounting for age and sex was used to predict association with steroid failure.

Results

Compared to steroid responsive cases, steroid failure was more likely to result in fulminant myocarditis (56.7% vs 19.6%, OR=5.37 [2.62–10.98] p<0.001) and all-cause in-hospital mortality (49.1% vs 12.9%, OR=6.50 [2.86–14.73] p<0.001) with shorter time from presentation to death (27.5 vs 43.0 days HR: 2.56 [1.45–4.50] p=0.001). When adjusting for age and sex, cases were more likely to be steroid-refractory if they were female (46.7% vs 30.1%, OR=2.77 [1.31–5.85] p=0.007), higher body mass index (27.2 vs 22.0, OR=1.09 [1.01–1.18] p=0.012), had higher intake creatine kinase (2800.5 vs 528.0 U/L, OR=1.48 [1.14–1.90] p=0.003) had higher intake troponin T (1.40 vs 0.25 ng/mL OR=1.63 [1.00–2.64] p=0.049), or had one or more concomitant non-cardiac immune-related adverse event (90.0% vs 74.2%, OR=3.10 [1.14–8.25] p<0.026). The only immune-related adverse events independently associated with steroid failure in myocarditis were myasthenia gravis-like syndrome (26.7% vs 8.2%, OR=3.84 [1.47–10.10] p=0.006) and myositis (45.0% vs 24.7%, OR=2.38 [1.16–4.92] p=0.018). Steroid failure was not significantly associated with cardiovascular or autoimmune history but was associated with a history of thymoma (12.0% vs 2.6%, OR=18.86 [0.10–356.7] p=0.05)

Conclusion(s)

Features such as female sex, high body mass index, and pre-existing thymoma as well as findings of elevated cardiac biomarkers and other non-cardiac immune-related adverse events – particularly myositis and myasthenia gravis-like syndrome – may represent a steroid-refractory phenotype of ICI-associated myocarditis. These results suggest that a multidisciplinary approach to diagnosing concomitant non-cardiac immune related adverse events is key to risk-stratifying ICI-associated myocarditis.

Forrest Plot

Funding Acknowledgement

Type of funding source: Private hospital(s). Main funding source(s): National Institutes of Health

Cardiovascular Toxicity Related to Cancer Treatment: A Pragmatic Approach to the American and European Cardio-Oncology Guidelines

The considerable progress made in the field of cancer treatment has led to a dramatic improvement in the prognosis of patients with cancer. However, toxicities resulting from these treatments represent a cost that can be harmful to short- and long-term outcomes. Adverse events affecting the cardiovascular system are one of the greatest challenges in the overall management of patients with cancer, as they can compromise the success of the optimal treatment against the tumor. Such adverse events are associated not only with older chemotherapy drugs such as anthracyclines but also with many targeted therapies and immunotherapies. Recognizing this concern, several American and European governing societies in oncology and cardiology have published guidelines on the cardiovascular monitoring of patients receiving potentially cardiotoxic cancer therapies, as well as on the management of cardiovascular toxicities. However, the low level of evidence supporting these guidelines has led to numerous discrepancies, leaving clinicians without a consensus strategy to apply. A cardio-oncology expert panel from the French Working Group of Cardio-Oncology has undertaken an ambitious effort to analyze and harmonize the most recent American and European guidelines to propose roadmaps and decision algorithms that would be easy for clinicians to use in their daily practice. In this statement, the experts addressed the cardiovascular monitoring strategies for the cancer drugs associated with the highest risk of cardiovascular toxicities, as well as the management of such toxicities.

Management of low blood pressure in ambulatory heart failure with reduced ejection fraction patients

Low blood pressure is common in patients with heart failure and reduced ejection fraction (HFrEF). While spontaneous hypotension predicts risk in HFrEF, there is only limited evidence regarding the relationship between hypotension observed during heart failure (HF) drug titration and outcome. Nevertheless, hypotension (especially orthostatic hypotension) is an important factor limiting the titration of HFrEF treatments in routine practice. In patients with signs of shock and/or severe congestion, hospitalization is advised. However, in the very frequent cases of non‐severe and asymptomatic hypotension observed while taking drugs with a class I indication in HFrEF, European and US guidelines recommend maintaining the same drug dosage. In instances of symptomatic or severe persistent hypotension (systolic blood pressure < 90 mmHg), it is recommended to first decrease blood pressure reducing drugs not indicated in HFrEF as well as the loop diuretic dose in the absence of associated signs of congestion. Unless the management of hypotension appears urgent, a HF specialist should then be sought rather than stopping or decreasing drugs with a class I indication in HFrEF. If symptoms or severe hypotension persist, no recommendations exist. Our HF group reviewed available evidence and proposes certain steps to follow in such situations in order to improve the pharmacological management of these patients.

Identification of anticancer drugs associated with atrial fibrillation: analysis of the WHO pharmacovigilance database

AIMS

The explosion of novel anticancer therapies has meant emergence of cardiotoxicity signals including atrial fibrillation (AF). Reliable data concerning the liability of anticancer drugs in inducing AF are scarce. Using the World Health Organization individual case safety report database, VigiBase®, we aimed to determine the association between anticancer drugs and AF.

METHODS AND RESULTS

A disproportionality analysis evaluating the multivariable-adjusted reporting odds ratios for AF with their 99.97% confidence intervals was performed for 176 U.S. Food and Drug Administration (FDA)- or European Medicines Agency (EMA)-labelled anticancer drugs in VigiBase®, followed by a descriptive analysis of AF cases for the anticancer drugs identified in VigiBase®. ClinicalTrial registration number: NCT03530215. A total of 11 757 AF cases associated with at least one anticancer drug were identified in VigiBase® of which 95.8% were deemed serious. Nineteen anticancer drugs were significantly associated with AF of which 14 (74%) are used in haematologic malignancies and 9 (45%) represented new AF associations not previously confirmed in literature including immunomodulating agents (lenalidomide, pomalidomide), several kinase inhibitors (nilotinib, ponatinib, midostaurin), antimetabolites (azacytidine, clofarabine), docetaxel (taxane), and obinutuzumab, an anti-CD20 monoclonal antibody.

CONCLUSION

Although cancer malignancy itself may generate AF, we identified 19 anticancer drugs significantly associated with a significant increase in AF over-reporting. This pharmacovigilance study provides evidence that anticancer drugs themselves could represent independent risk factors for AF development. Dedicated prospective clinical trials are now required to confirm these 19 associations. This list of suspected anticancer drugs should be known by physicians when confronted to AF in cancer patients, particularly in case of haematologic malignancies.

Acute Coronary Syndrome With Immune Checkpoint Inhibitors: A Proof-of-Concept Case and Pharmacovigilance Analysis of a Life-Threatening Adverse Event

Isolated cases of acute coronary syndrome (ACS) associated with immune checkpoint inhibitors (ICIs) have been described without the establishment of a formal cause-and-effect relationship between treatment and adverse event. We reported a case of ACS after the first administration of an ICI and with a fatal recurrence in another coronary area immediately after readministration. According to guidelines, causality was considered to be certain. Subsequently, we queried the French pharmacovigilance database and found 4 cases of ACS with coronary artery thrombosis. Causality was probable in those patients. These data suggest that ACS may be another life-threatening cardiac adverse event occurring with ICI exposure.

[Myocarditis: Uncommon but severe toxicity of immune checkpoint inhibitors]

Traditional cancer therapies, such as treatment with anthracyclines and chest radiation, are known to induce cardiovascular complications. Currently, the increase of cancer therapies will involve new mechanisms such as cancer immunotherapies, also called immune checkpoint inhibitors (PD-1, PD-L1 and CTLA-4 inhibitors). These treatments have shown long-term remissions in subgroup of cancers, including melanomas, non-small-cell lung cancer, urothelial carcinoma, renal cell carcinoma, squamous cell carcinoma of the head and neck and colorectal cancer. Although these treatments will change the natural course of these cancers, they may sometimes induce cardiovascular complications, which has been reported as about 1 % in the literature. Currently, the physicians must keep in mind one uncommon but severe cardiac complication: auto-immune myocarditis. The clinical presentation may include various symptoms like chest pain, heart failure or rhythm disorders. In this situation, a baseline cardiologic check-up before starting cancer immunotherapy may be very helpful. Cardiac biomarkers (troponin and brain natriuretic peptide) and 12-lead resting electrocardiogram must be promptly performed when myocarditis is suspected. A cardiologist's opinion must be requested in emergency to discuss both a transthoracic echocardiography and the appropriate treatment (stopping immunotherapy, adding immunosuppressive treatment such as corticoids) and the monitoring in an intensive care unit. Cardiac MRI and endomyocardial biopsies may help to approach the final diagnosis. In this situation, other cancer therapies may be discussed.

Pulmonary hypertension in patients with myeloproliferative neoplasms: A large cohort of 183 patients

BACKGROUND

Chronic myeloproliferative neoplasms (MPN) are recognized as a cause of pulmonary hypertension (pH). We ought to describe the prevalence and characteristics of PH in a cohort of MPN who were screened using transthoracic echocardiography (TTE).

METHODS

One hundred eighty-three newly diagnosed consecutive MPN patients were prospectively evaluated using TTE to detect PH.

RESULTS

Two patients were diagnosed with chronic eosinophilic leukemia, two patients had post-essential thrombocythemia (ET) myelofibrosis (MF), two patients had post-polycythemia vera (PV) MF, 11 patients had primary myelofibrosis (PMF), 28 patients had chronic myeloid leukemia (CML), 51 patients had PV, and 87 patients had ET. TTE was used to determine PH, and PH was suspected in 16 of 183 patients as follows: four with PV, seven with ET, two with PMF, and three with CML. Two patients with ET were excluded because of global cardiac failure. Three patients underwent right heart catheterization to confirm PH. The 14 (7.7%) patients with PH had no cardiac or lung disease that directly involved MPN in PH development.

CONCLUSION

In this large cohort of 183 MPN patients, TTE was used to diagnose PH, and 14 patients (7.7%) developed PH. This prevalence was lower than expected based on previously reported data, but it remains higher than in the general population.

Mechanical characterisation of human ascending aorta dissection

Mechanical characteristics of both the healthy ascending aorta and acute type A aortic dissection were investigated using in vitro biaxial tensile tests, in vivo measurements via transoesophageal echocardiography and histological characterisations. This combination of analysis at tissular, structural and microstructural levels highlighted the following: (i) a linear mechanical response for the dissected intimomedial flap and, conversely, nonlinear behaviour for both healthy and dissected ascending aorta; all showed anisotropy; (ii) a stiffer mechanical response in the longitudinal than in the circumferential direction for the healthy ascending aorta, consistent with the histological quantification of collagen and elastin fibre density; (iii) a link between dissection and ascending aorta stiffening, as revealed by biaxial tensile tests. This result was corroborated by in vivo measurements with stiffness index, β, and Peterson modulus, E_p, higher for patients with dissection than for control patients. It was consistent with histological analysis on dissected samples showing elastin fibre dislocations, reduced elastin density and increased collagen density. To our knowledge, this is the first study to report biaxial tensile tests on the dissected intimomedial flap and in vivo stiffness measurements of acute type A dissection in humans.

High incidence of atrial fibrillation in patients treated with ibrutinib

Objective

Atrial fibrillation (AF) is one of the most common side effects of ibrutinib, a drug that has dramatically improved the prognosis of chronic B-cell malignancies such as chronic lymphocytic leukaemia (CLL). The true incidence of ibrutinib-related AF (IRAF) is not well known and its therapeutic management poses unique challenges especially due to the inherent risk of bleeding. We aimed to determine the incidence and predictors of IRAF, and to analyse its management and outcome.

Methods

A standardised monitoring was applied at two cardio-oncology clinics in consecutive patients referred before and during ibrutinib therapy. The primary endpoint was the incidence of IRAF. The excess of AF incidence with ibrutinib was studied by comparing the incidence of IRAF with the expected incidence of AF in general population and in patients with CLL not exposed to ibrutinib.

Results

53 patients were included. The incidence of IRAF was 38% at 2 years and the risk was 15-fold higher than the AF risk in both the general population and patients with CLL not exposed to ibrutinib (p<0.0001). The majority of cases occurred in asymptomatic patients within the first 6 months. Left atrial volume index ≥40 mL/m² at treatment initiation identified patients at high risk of developing IRAF. No major bleeding events occurred in patients on ibrutinib, although the majority of patients with IRAF were treated with anticoagulants.

Conclusions

This cardio-oncology study showed that the risk of IRAF was much higher than previously reported. The majority of cases occurred in asymptomatic patients justifying close monitoring.

Physiological stress markers during breath-hold diving and SCUBA diving

This study investigated the sources of physiological stress in diving by comparing SCUBA dives (stressors: hydrostatic pressure, cold, and hyperoxia), apneic dives (hydrostatic pressure, cold, physical activity, hypoxia), and dry static apnea (hypoxia only). We hypothesized that despite the hypoxia induces by a long static apnea, it would be less stressful than SCUBA dive or apneic dives since the latter combined high pressure, physical activity, and cold exposure. Blood samples were collected from 12SCUBA and 12 apnea divers before and after dives. On a different occasion, samples were collected from the apneic group before and after a maximal static dry apnea. We measured changes in levels of the stress hormones cortisol and copeptin in each situation. To identify localized effects of the stress, we measured levels of the cardiac injury markers troponin (cTnI) and brain natriuretic peptide (BNP), the muscular stress markers myoglobin and lactate), and the hypoxemia marker ischemia-modified albumin (IMA). Copeptin, cortisol, and IMA levels increased for the apneic dive and the static dry apnea, whereas they decreased for the SCUBA dive. Troponin, BNP, and myoglobin levels increased for the apneic dive, but were unchanged for the SCUBA dive and the static dry apnea. We conclude that hypoxia induced by apnea is the dominant trigger for the release of stress hormones and cardiac injury markers, whereas cold or and hyperbaric exposures play a minor role. These results indicate that subjects should be screened carefully for pre-existing cardiac diseases before undertaking significant apneic maneuvers.

OCT Analysis of Very Early Strut Coverage of the Synergy Stent in Non-ST Segment Elevation Acute Coronary Syndrome Patients

OBJECTIVES

Early endothelialization of drug-eluting stent (DES) is a major challenge to reduce the risk of stent thrombosis and the duration of dual-antiplatelet therapy (DAPT) in high bleeding-risk patients. The aim of the present study is to evaluate very early strut coverage with optical coherence tomography (OCT) of the Synergy stent (Boston Scientific) at 1 month in non-ST segment elevation acute coronary syndrome (NSTE-ACS) patients.

METHODS

This substudy of the EARLY trial prospectively included NSTE-ACS patients treated with the Synergy DES. OCT analysis of the Synergy stent was performed during a staged PCI of additional lesions at 1 month. The primary endpoint was the percentage of covered struts assessed with OCT at 1 month.

RESULTS

Twenty-four patients were included, with a mean stent length of 35.9 ± 10.1 mm per patient. The rate of covered struts was 78.5% out of 3839 struts analyzed. Nineteen patients (79.2%) had at least 70% of their struts covered. The average neointimal thickness was 0.0508 ± 0.016 mm.

CONCLUSIONS

In NSTE-ACS patients undergoing culprit percutaneous coronary intervention with the Synergy stent, the rate of covered struts at 1 month was 78.5%. This rapid coverage is in line with the results of clinical trials demonstrating the safety of short-duration DAPT in selected patients who are at high bleeding risk and treated with new-generation DES options.

Sphere-Tubule Superstructures through Supramolecular and Supracolloidal Assembly Pathways

While colloids have been widely employed as models for atoms and molecules, the current study proposes to extend their use as building blocks for supracolloidal frameworks. Hereby, the self-assembly between highly anisotropic supramolecular microtubules and soft spherical fluorescent microgels is explored using confocal laser scanning microscopy. The influence of the particle size and charge with respect to the catanionic tubule composition, which consists of two oppositely charged bile salt derivatives, is investigated. Under certain conditions, microgel particles are found to specifically interact with the extremities of the tubular aggregates and hierarchically self-assemble into various superstructures varying from virus-like assemblies to supracolloidal networks. The reported approach is envisioned to open new self-assembly routes toward ordered hybrid superstructures where the spherical colloids act as responsive linkers of tubular structures.

Doppler echocardiography for assessment of systemic vascular resistances in cardiogenic shock patients

OBJECTIVE

Impaired vascular tone plays an important role in cardiogenic shock. Doppler echocardiography provides a non-invasive estimation of systemic vascular resistance. The aim of the present study was to compare Doppler echocardiography with the transpulmonary thermodilution method for the assessment of systemic vascular resistance in patients with cardiogenic shock.

METHODS

This prospective monocentric comparison study was conducted in a single cardiology intensive care unit (Hopital Nord, Marseille, France). We assessed the systemic vascular resistance index by both echocardiography and transpulmonary thermodilution in 28 patients admitted for cardiogenic shock, on admission and after the introduction of an inotrope or vasopressor treatment.

RESULTS

A total of 35 paired echocardiographic and transpulmonary thermodilution estimations of the systemic vascular resistance index were compared. Echocardiography values ranged from 1309 to 3526 dynes.s.m²/cm⁵ and transpulmonary thermodilution values ranged from 1320 to 3901 dynes.s.m²/cm⁵. A statistically significant correlation was found between echocardiography and transpulmonary thermodilution (r=0.86, 95% confidence interval (CI) 0.74, 0.93; P<0.0001). The intraclass correlation coefficient was 0.84 (95% CI 0.72, 0.92). The mean bias was -111.95 dynes.s.m²/cm⁵ (95% CI -230.06, 6.16). Limits of agreement were -785.86, 561.96.

CONCLUSIONS

Doppler echocardiography constitutes an accurate non-invasive alternative to transpulmonary thermodilution to provide an estimation of systemic vascular resistance in patients with cardiogenic shock.

Uric acid levels are associated with endothelial dysfunction and severity of coronary atherosclerosis during a first episode of acute coronary syndrome

The role of serum uric acid in coronary artery disease has been extensively investigated. It was suggested that serum uric acid level (SUA) is an independent predictor of endothelial dysfunction and related to coronary artery lesions. However, the relationship between SUA and severity of coronary atherosclerosis evaluated via endothelial dysfunction using peripheral arterial tone (PAT) and the reactive hyperhemia index (RHI) has not been investigated during a first episode of acute coronary syndrome (ACS). The aim of our study was to address this point. We prospectively enrolled 80 patients with a first episode of ACS in a single-center observational study. All patients underwent coronary angiography, evaluation of endothelial function via the RHI, and SUA measurement. The severity of the coronary artery lesion was assessed angiographically, and patients were classified in three groups based on the extent of disease and Gensini and SYNTAX scores. Endothelial function was considered abnormal if RHI < 1.67. We identified a linear correlation between SUA and RHI (R² = 0.66 P < 0.001). In multivariable analyses, SUA remained associated with RHI, even after adjustment for traditional cardiovascular risk factors and renal function. SUA was associated with severity of coronary artery disease. SUA is associated with severity of coronary atherosclerosis in patients with asymptomatic hyperuricemia. This inexpensive, readily measured biological parameter may be useful to monitor ACS patients.

Uric acid levels are associated with endothelial dysfunction and severity of coronary atherosclerosis during a first episode of acute coronary syndrome

The role of serum uric acid in coronary artery disease has been extensively investigated. It was suggested that serum uric acid level (SUA) is an independent predictor of endothelial dysfunction and related to coronary artery lesions. However, the relationship between SUA and severity of coronary atherosclerosis evaluated via endothelial dysfunction using peripheral arterial tone (PAT) and the reactive hyperhemia index (RHI) has not been investigated during a first episode of acute coronary syndrome (ACS). The aim of our study was to address this point. We prospectively enrolled 80 patients with a first episode of ACS in a single-center observational study. All patients underwent coronary angiography, evaluation of endothelial function via the RHI, and SUA measurement. The severity of the coronary artery lesion was assessed angiographically, and patients were classified in three groups based on the extent of disease and Gensini and SYNTAX scores. Endothelial function was considered abnormal if RHI < 1.67. We identified a linear correlation between SUA and RHI (R² = 0.66 P < 0.001). In multivariable analyses, SUA remained associated with RHI, even after adjustment for traditional cardiovascular risk factors and renal function. SUA was associated with severity of coronary artery disease. SUA is associated with severity of coronary atherosclerosis in patients with asymptomatic hyperuricemia. This inexpensive, readily measured biological parameter may be useful to monitor ACS patients.

[How to organise cardiovascular management of cancer patients?]

How to organise cardiovascular management of cancer patients? Advances in cancer therapy have reduced cancer mortality. However, these results are sometimes achieved at the cost of cardiovascular adverse events that may limit the overall benefit of treatment. Cardio-oncology is a recent discipline that aims to prevent, screen and manage cardiovascular diseases associated with or secondary to cancer treatment without compromising its effectiveness. These goals must therefore be integrated into the patient care program at the time of cancer diagnosis. Therefore, a cardiovascular toxicity risk assessment should be conducted prior treatment to identify patients candidate for closer monitoring. In parallel with their oncologic follow-up, these high-risk patients should receive cardiovascular follow-up that should not be restricted to a solely measurement of the left ventricular ejection fraction. Indeed, toxicities can be multiple, so the assessment must be comprehensive and should include at least clinical examination, ECG, cardiac imaging, and sometimes biomarkers. In the case of cardiovascular events, this organisation will enable an earlier and coordinated management with oncologists, which will result in an improvement of the patients' overall prognosis.

Prevalence and characteristics of coronary artery disease in heart failure with preserved and mid-range ejection fractions: A systematic angiography approach

BACKGROUND

Guidelines recommend careful screening and treatment of coronary artery disease (CAD) in heart failure with preserved or mid-range ejection fraction (HFpEF/HFmEF).

AIM

We aimed to determine the prevalence and characteristics of CAD using a prospective systematic coronary angiography approach.

METHODS

A systematic coronary angiography protocol was applied in consecutive patients admitted for HFpEF/HFmEF during a 6-month period in a single centre. History of CAD and results of angiography, including revascularization, were reported.

RESULTS

Of the 164 patients with HFpEF/HFmEF who were included, an angiography assessment was applied in 108 (66%) (median age: 79 years [interquartile range: 70-85 years]; 54% were women). In our analysis, 64% (95% confidence interval [CI] 55-73%) of patients had a significant coronary stenosis corresponding to a global CAD prevalence of 80% (95% CI 73-88%). The prevalence of CAD was similar for HFpEF and HFmEF. The left main coronary artery presented a significant stenosis in 6.5% of cases and 39% of patients had a two- or three-vessel disease. The rate of significant coronary stenosis was non-significantly higher in patients with a history of CAD. Patients with HFpEF/HFmEF with and without CAD did not differ in clinically meaningful ways, in terms of symptoms or laboratory and echocardiography results. This strategy led to complete revascularization in 36% of patients with significant stenosis and in 23% of all patients with HFpEF/HFmEF.

CONCLUSIONS

Our study differs from others in that we used a systematic angiography approach. The results suggest a much higher prevalence of CAD in HFpEF/HFmEF than previously reported and should encourage clinicians to aggressively identify this co-morbidity.

Ventricular Arrhythmia Occurrence and Compliance in Patients Treated With the Wearable Cardioverter Defibrillator Following Percutaneous Coronary Intervention

BACKGROUND

The wearable cardioverter defibrillator (WCD) is a life-saving therapy in patients with high risk of arrhythmic death. We aimed to evaluate ventricular arrhythmia (VA) occurrence rate and compliance with the WCD during the first 90 days following myocardial revascularisation with percutaneous coronary intervention (PCI) in patients with left ventricular ejection fraction (LVEF) <30%.

METHODS

From September 2015 to November 2016, clinical characteristics, WCD recordings and compliance data of the aforementioned subset of patients were prospectively collected.

RESULTS

Twenty-four patients (men=20, 80%) were included in this analysis. Mean age was 56±10 years and mean LVEF at enrolment was 26.6±4.3%. During a mean wearing period of 3.0±1.3 months, two episodes of VA occurred in two patients (8.3%): one successfully treated with WCD shock and one with spontaneous termination. The mean and median daily use of the WCD was 21.5hours and 23.5hours a day, respectively. Eighteen patients (75%) wore the WCD more than 22hours a day.

CONCLUSIONS

The rate of VA, during the WCD period use after myocardial revascularisation with PCI, was high in our study. Otherwise it underlined that patient compliance is critical during the WCD period use. Remote monitoring and patient education are keys to achieve good compliance.

Towards Addressing the Body Electrolyte Environment via Sweat Analysis:Pilocarpine Iontophoresis Supports Assessment of Plasma Potassium Concentration

Electrolyte concentration in sweat depends on environmental context and physical condition but also on the pathophysiological status. Sweat analyzers may be therefore the future way for biological survey although how sweat electrolyte composition can reflect plasma composition remains unclear. We recruited 10 healthy subjects and 6 patients to have a broad range of plasma electrolyte concentrations (chloride, potassium and sodium) and pH. These variables were compared to those found in sweat produced following cycling exercise or pilocarpine iontophoresis, a condition compatible with operating a wearable device. We found no correlation between plasma and sweat parameters when exercise-induced sweat was analyzed, and we could identify a correlation only between plasma and sweat potassium concentration (R = 0.78, p < 0.01) when sweat was induced using pilocarpine iontophoresis. We tested measurement repeatability in sweat at 24hr-interval for 3 days in 4 subjects and found a great intra-individual variability regarding all parameters in exercise-induced sweat whereas similar electrolyte levels were measured in pilocarpine-induced sweat. Thus, electrolyte concentration in sweat sampled following physical activity does not reflect concentration in plasma while pilocarpine iontophoresis appears to be promising to reproducibly address sweat electrolytes, and to make an indirect evaluation of plasma potassium concentration in chronic kidney disease and arrhythmia.