Ventricular arrhythmias in patients with immune checkpoint inhibitor myocarditis

Background

Immune checkpoint inhibitor (ICI)-associated myocarditis is associated with a markedly increased risk of morbidity and mortality. The occurrence of ventricular arrhythmias (VA) in patients with ICI-associated myocarditis has not been well characterized.

Purpose

The aim of this study was to determine the characteristics and risk factors for severe VA in patients with ICI myocarditis.

Methods

The cohort consisted of 202 patients with ICI myocarditis. Ventricular arrhythmias were defined as a composite of sustained ventricular tachycardia and ventricular fibrillation. We used a multivariable logistic regression model to test the association between clinical variables and the development of VA.

Results

From a cohort of 202 patients with ICI myocarditis (67±13 years, 35% female, 60% hypertension, 23% diabetes mellitus), 41 (20.3%) developed VA, of which, 33 had VT and 8 had VF. The median time from admission to VF was 144 hours and to VT was 72 hours. A VA occurred in 17.5% of patients with a normal LVEF, and 25% of patients with reduced LVEF. On univariate analysis, a QRS duration >110ms (OR 2.88, 95% CI 1.40 to 6.16, P=0.005) and a QTc duration >470ms were associated with an increased probability of VA (OR 2.58, 95% CI 1.23, 5.41, P=0.012). The association remained significant after adjustment for age and gender. Additionally, a longer time from admission to initiation of corticosteroids was associated with a higher probability of VA (OR 1.06, 95% CI 1.01 to 1.13, P=0.027). The association between the time from admission to administration of corticosteroids and probability of VA remained significant after adjustment for age, gender, and LVEF on admission (OR, 1.06, 95% CI 1.00, 1.13, P=0.037) where each 6-hour delay in the initiation of corticosteroids was associated with a 4% increase in the risk for VA.

Conclusions

Ventricular arrhythmias are common in the setting of ICI myocarditis and are observed in patients presenting with both a preserved and a reduced LVEF. Wider QRS and longer QT at presentation and longer time from admission to initiation of corticosteroids were associated with an increased risk of VA.

Funding Acknowledgement

Type of funding sources: None.

Cardioprotection using strain-guided management of potentially cardiotoxic cancer therapy: 1 year results of the SUCCOUR trial

Background

Conventional criteria for diagnosis of chemotherapy-related cardiac dysfunction (CTRCD) are dependent on the recognition of heart failure (HF) symptoms and/or changes in LVEF. However, the low sensitivity of EF for minor changes in LV function may delay initiation of cardio-protective therapy (CPT). Global longitudinal strain (GLS) is a robust and sensitive marker of LV dysfunction (LVD), but existing observational data are insufficient to justify changing the diagnostic criteria for CTRCD.

Purpose

To identify whether GLS guidance of CPT would improve cardiac function of at risk patients undergoing potentially cardiotoxic chemotherapy, compared with usual care.

Methods

In this international multicenter prospective randomized controlled trial, 331 pts from 23 international sites taking anthracyclines with another risk factor for HF were randomly allocated into 166 undergoing GLS-guided (CPT for >12% relative reduction in GLS using Echopac software) and 165 EF-guided (CPT for >10% absolute reduction of EF). Pts were followed over 1 year for the primary end-point (ΔEF) with 3D echo (3DE); 2D echo (2DE) was used when 3D images were unsuitable for measurement. Development of CTRCD (EF reduction of 10% to <55%) was a secondary endpoint.

Results

Of 331 randomized patients, 24 withdrew before follow-up imaging was performed (2 died, and rest withdrew or were lost to follow-up). Among 307 patients (age 54±12 years, 94% women) with follow-up 1.0±0.2 years, 277 had breast cancer, 30 had lymphoma/leukemia. HF risk factors were prevalent: 89 (29%) had hypertension and 39 (13%) had diabetes mellitus. The most common chemotherapy regimen during this study was the combination of anthracycline and trastuzumab. The baseline 3D LVEF was 61±5%, and GLS was −20.8±3.2%. At 1 year follow-up, 31 (10%) met CTRCD and was reduced in the GLS-guided arm (Table 1), although new LV dysfunction (EF<55%) and change of EF were not different.

Conclusion

In this international multicentre trial, the incidence of CTRCD was reduced by strain-guided cardioprotection. Although the final EF and the number of pts developing EF <55% was not altered by strain-guided therapy, this reduces meaningful reduction of EF to the abnormal range. The results support the use of GLS in surveillance for CTRCD.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): General Electric Medical Systems

Association between global longitudinal strain and cardiopulmonary fitness in patients with breast cancer

Background

Anthracycline and trastuzumab therapies improve survival in the cancer population, but are limited by treatment induced cardiotoxicity. Echocardiography derived global longitudinal strain (GLS) permits more sensitive detection of cardiotoxicity than left ventricular ejection fraction (LVEF). However, the clinical implication of a reduction in GLS in cancer survivors is unknown.

Purpose

To define the association between GLS and cardiopulmonary fitness in women with breast cancer immediately post cancer therapy.

Methods

Women with HER2+ early stage breast cancer (EBC, Stage I-III) receiving anthracyclines followed by trastuzumab were recruited prospectively and followed between January 2015 and December 2019 with echocardiography during therapy. Left ventricular peak systolic GLS (GE EchoPAC, 3 apical views) and 3D-LVEF were measured prior to anthracyclines, and after completion of trastuzumab at 12 months. Exercise capacity was measured using a supine bicycle cardiopulmonary exercise test. Results of exercise testing at end of treatment were compared between patients with and without reduced GLS (absolute value ≤18% vs >18%) at the end of therapy.

Results

Amongst 128 women, 43 (34%) had a GLS ≤18% at the end of trastuzumab therapy. Baseline patient demographics including tumor characteristics and cardiac risk factors were similar between those with normal and abnormal GLS. During treatment 33 (25.8%) participants developed cardiotoxicity defined by the CREC criteria based on 3D-LVEF. Significant baseline (pre-cancer treatment) differences were found between groups for GLS (GLS 21.2±1.8 vs 19.6±2.2, p<0.001) and 3D LVEF (61.8±3.5 vs 60.2±3.7%, p=0.02) for those with GLS >18% and GLS ≤18% respectively at the completion of trastuzumab. Compared to those with GLS >18% those with GLS ≤18% had lower VO2peak (17.4±3.8 mL.kg-1.min-1 versus 20.2±4.9 mL.kg-1.min-1, p=0.001) despite similar effort (respiratory exchange ratio 1.14 versus 1.12, p=0.30). GLS following therapy (β coefficient: −0.596, SE 0.255; p=0.02) and age (β coefficient: −0.115, SE 0.057; p=0.047) were the only parameters associated with VO2peak after adjusting for relevant confounding factors.

Conclusion

A significant proportion of women receiving cancer therapy for HER2+ EBC had reduced GLS at end of treatment. Abnormal GLS at the end of cancer treatment was associated with lower VO2peak. Reduced VO2peak is strongly associated with late-occurring cardiovascular events and should prompt closer cardiac monitoring, cardiac risk factor management, and referral to exercise rehabilitation programs.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Canadian Institute of Health Research

P2618Association of left ventricular ejection fraction with mortality and hospitalizations

Background

Although 2-dimensional echocardiography (2DE) is widely used to measure left ventricular ejection fraction (LVEF), the prognostic value of 2DE-derived LVEF has not been clearly demonstrated in a broad range of patients, including those acutely hospitalized as well as ambulatory patients. In particular, the prognostic value of echocardiographic LVEF has not been demonstrated for cardiovascular and heart failure hospitalizations.

Purpose

To determine if greater degrees of LV dysfunction are associated with progressively increasing risks of death or cardiovascular hospitalizations among patients undergoing echocardiography in hospital or outpatient settings.

Methods

We examined quantitative LVEFs from patient-level echocardiographic reports at 3 large hospital laboratories, which were linked to the Canadian Institute for Health Information hospitalization database and to death registries in Ontario, Canada. LVEF was categorized as <25%, 25–35%, 36–45%, or 46–55% (reference). Analyses were performed using cause-specific hazard competing risk models and stratified by: a) outpatient vs. inpatient echocardiogram, and b) if inpatient study, whether the reason for hospitalization was cardiac or noncardiac in nature.

Results

In the echocardiographic cohort of 27,323 patients (median age 68 [IQR: 58–77], 14,828 women [31.7%]), greater reductions in LVEF were associated with higher rates of all-cause mortality, with adjusted hazard ratios (95% CI) of 1.67 (1.57, 1.77) for LVEF <25%, 1.30 (1.24, 1.36) for LVEF 25–35%, and 1.17 (1.11, 1.23) for LVEF 36–45%, compared to LVEF 46–55% (all p<0.001). The cumulative incidence of cardiovascular death was higher as LVEF progressively worsened (Figure). The rate of heart failure hospitalizations was also increased with hazard ratios of 1.71 (1.59, 1.85) for LVEF <25%, 1.39 (1.31, 1.48) for LVEF 25–35%, and 1.21 (1.13, 1.29) for LVEF 36–45%, compared to LVEF 46–55% (all p<0.001). Cardiovascular hospitalizations were also increased with hazard ratios of 1.35 (1.27, 1.42), 1.21 (1.16, 1.27), and 1.13 (1.07, 1.18) for LVEFs <25%, 25–35%, and 36–45%, respectively (all p<0.001). The risk of mortality and hospitalizations increased comparably with greater reductions in LVEF during both inpatient cardiac or noncardiac admissions (p<0.001).

Cumulative incidence of CV death

Conclusions

Quantitative LVEF assessed by 2DE is potent prognostically and was able to stratify the risk of both death and hospitalization outcomes in a wide range of clinical settings. Patients with reduced LVEF measured on inpatient or outpatient echocardiograms, and even in the context of non-cardiac admission, should be considered an at-risk group in whom quality of care metrics could be evaluated in future studies.

Acknowledgement/Funding

Canadian Institutes of Health Research, Heart and Stroke Foundation, and the Ted Rogers Centre for Heart Research

Interventions for preventing cardiomyopathy due to anthracyclines: a Bayesian network meta-analysis

Background

The relative efficacy of interventions for primary prevention of anthracycline-associated cardiotoxicity is unknown.

Methods

We conducted a systematic review of randomized controlled trials for primary prevention of anthracycline-associated cardiotoxicity in adult cancer patients. We used hierarchal outcome definitions in the following order of priority: (1) composite of heart failure or decline in left ventricular ejection fraction, (2) decline in ejection fraction, or (3) heart failure. Data were analyzed using a Bayesian network meta-analysis with random effects.

Results

A total of 16 trials reported cardiotoxicity as a dichotomous outcome among 1918 patients, evaluating dexrazoxane, angiotensin antagonists, beta-blockers, combination angiotensin antagonists and beta-blockers, statins, Co-enzyme Q-10, prenylamine, and N-acetylcysteine. Compared with control, dexrazoxane reduced cardiotoxicity with a pooled odds ratio (OR) of 0.26 (95% credible interval [CrI] 0.11-0.74) and had the highest probability (33%) of being most effective. No other agent was demonstrably better than placebo. Angiotensin antagonists had an 84% probability of being most effective in a sensitivity analysis excluding one outlying study (OR 0.06 [95% CrI 0.01- 0.24]). When the outcome was restricted to heart failure, dexrazoxane was associated with an OR of 0.12 (95% CrI 0.06-0.23) relative to control and had 58% probability of being most effective, while angiotensin antagonists had an OR of 0.18 (95% CrI 0.05-0.55). Available data suggested that dexrazoxane and angiotensin antagonists did not affect malignancy response rate or risk of death.

Conclusion

Moderate quality data suggest that dexrazoxane, and low quality data suggest angiotensin antagonists, are likely to be effective for cardiotoxicity prevention.

Fulminant myocarditis owing to high-dose interleukin-2 therapy for metastatic melanoma

High-dose interleukin-2 (IL-2) therapy may cause acute myocarditis characterised by diffuse myocardial involvement and occasionally fulminant heart failure. Cardiac MRI (CMRI) provides a comprehensive assessment of myocardial function, inflammation and injury in a single examination and has shown value in the diagnosis of myocarditis. We report a case of a 54-year-old male with metastatic melanoma who developed acute severe myocarditis with fulminant heart failure after high-dose IL-2 therapy. CMRI using a combination of T(2) weighted imaging and T(1) weighted late post-gadolinium enhancement techniques played a key role in establishing the diagnosis. To our knowledge we present the first case report of the combined use of T(1) and T(2) weighted CMRI techniques to diagnose IL-2 induced myocarditis.

The MCT ketogenic diet: effects on animal seizure models

Male Wistar rat pups were weaned at 20 days of age and placed on either a control diet or a ketogenic diet containing medium-chain triglyceride (MCT) oil. After 10 days on the diets, they were subjected to one of four seizure tests-maximal electric shock, threshold electroconvulsive shock, threshold pentylenetetrazol, or maximal pentylenetetrazol. After testing, subjects were sacrificed and blood samples were analyzed for beta-hydroxybutyrate concentration. It was found that the MCT diet produced blood levels of beta-hydroxybutyrate that were comparable to or higher than those commonly reported in clinical studies. However, no anticonvulsant effects were seen in any of the seizure tests. In fact, the tests involving maximal seizures actually showed proconvulsant effects. It appears that clinical levels of ketones may be present in the bloodstream without suppressing seizures.

Neuroprotective effects of acetylsalicylic acid in an animal model of focal brain ischemia

Recent studies have shown neuroprotective effects of acetylsalicylic acid (ASA) in cell cultures and hippocampal slices. The present study demonstrates similar effects in a whole-animal modal of focal ischemic stroke. Focal cortical ischemia was produced in Wistar rats by ligation of the common carotid and middle cerebral arteries. Subjects were sacrificed 8 days after ligation, and infarct volume was assessed via automated densitometry. Significant reductions in infarct volume were seen with i.p. ASA doses of 15 mg/kg and above. Reductions occurred when ASA was injected 2 h or 30 min before ligation, but not when it was injected 8 or 24 h before, or 30 min after ligation.