Multiparametric Early Detection and Prediction of Cardiotoxicity Using Myocardial Strain, T1 and T2 Mapping, and Biochemical Markers: A Longitudinal Cardiac Resonance Imaging Study During 2 Years of Follow-Up

BACKGROUND

Our goal was to evaluate the ability of cardiovascular magnetic resonance for detecting and predicting cardiac dysfunction in patients receiving cancer therapy. Left ventricular ejection fraction, global and regional strain utilizing fast-strain-encoded, T1 and T2 mapping, and cardiac biomarkers (troponin and BNP [brain natriuretic peptide]) were analyzed.

METHODS

Sixty-one patients (47 with breast cancer, 11 with non-Hodgkin lymphoma, and 3 with Hodgkin lymphoma) underwent cardiovascular magnetic resonance scans at baseline and at regular intervals during 2 years of follow-up. The percentage of all left ventricular myocardial segments with strain ≤-17% (normal myocardium [%]) was analyzed. Clinical cardiotoxicity (CTX) and sub-CTX were defined according to standard measures.

RESULTS

Nine (15%) patients developed CTX, 26 (43%) had sub-CTX. Of the 35 patients with CTX or sub-CTX, 24 (69%) were treated with cardioprotective medications and showed recovery of cardiac function. The amount of normal myocardium (%) exhibited markedly higher accuracy for the detection of CTX and sub-CTX compared with left ventricular ejection fraction, T1, and T2 mapping as well as troponin I (Δareas under the curve=0.20, 0.24, and 0.46 for normal myocardium (%) versus left ventricular ejection fraction, troponin I, and T1 mapping, P<0.001 for all). In addition, normal myocardium (%) at baseline accurately identified patients with subsequent CTX (P<0.001), which was not achieved by any other markers.

CONCLUSIONS

Normal myocardium (%) derived by fast-strain-encoded cardiovascular magnetic resonance, is an accurate and sensitive tool that can establish cardiac safety in patients with cancer undergoing cardiotoxic chemotherapy not only for the early detection but also for the prediction of those at risk of developing CTX. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03543228.

Effects of nitrogen fertilization and dried distillers grains supplementation: nitrogen use efficiency

In a 3-yr study, 135 crossbred steers (330 ± 10 kg) were used in a randomized complete block design to evaluate corn dried distillers grains plus solubles (DDGS) fed to yearling steers as a substitute for forage and N fertilizer and its effect on N use efficiency in yearling steers grazing smooth bromegrass pastures. Steers were initially stocked at 6.8 animal unit months (AUM)/ha on nonfertilized smooth bromegrass pastures (CONT), at 9.9 AUM/ha on smooth bromegrass pastures fertilized with 90 kg of N/ha (FERT), or at 9.9 AUM/ha on nonfertilized smooth bromegrass pastures with 2.3 kg (DM) of DDGS supplemented daily per steer (SUPP). Paddock was the experimental unit, with 3 replications per treatment per year for 3 yr. Paddocks were strip-grazed, and put-and-take cattle were used to maintain similar grazing pressure among treatment paddocks during the 160-d grazing season. Steers consumed less forage (P < 0.01), but total N intake for SUPP was greater (P < 0.01) per steer and per hectare than for FERT, and both were greater (P < 0.01) than for CONT. Nitrogen retention for steers in the SUPP treatment was increased (P < 0.01) by 31% compared with N retention in the CONT and FERT treatments. Nitrogen retention per hectare for SUPP was 30 and 98% greater (P < 0.01) than N retention per hectare for FERT and CONT, respectively. Nitrogen excretion per steer and per hectare were also greater (P < 0.01) for SUPP than FERT, and both were increased (P < 0.01) compared with CONT. Animal N use efficiency was similar (P = 0.29) for steers in the CONT, FERT, and SUPP treatments. However, system-based N use improved (P < 0.01) by 144% for SUPP compared with FERT. The DDGS increased N intake and N excretion in yearling steers. However, because of improvements in BW gain and increases in stocking rate of pastures, DDGS can be a useful tool to increase the efficiency of N use in smooth bromegrass grazing systems.

Fast-Strain Encoded Cardiac Magnetic Resonance During Vasodilator Perfusion Stress Testing

Background: Cardiac magnetic resonance perfusion imaging during vasodilator stress is an established modality in patients with suspected and known coronary artery disease (CAD). Aim: This study aimed to evaluate the performance of fast-Strain-Encoded-MRI (fast-SENC) for the diagnostic classification and risk stratification of patients with ischemic heart disease. Methods: Perfusion and fast-SENC cardiac magnetic resonance (CMR) images were retrospectively analyzed in 111 patients who underwent stress CMR. The average myocardial perfusion score index, global and segmental longitudinal and circumferential strain (GLS and GCS and SLS and SCS, respectively), were measured at rest and during stress. The combination of SLS and SCS was referred to as segmental aggregate strain (SAS). Segments exhibiting perfusion defects or SAS impairment during stress were defined as "ischemic." All-cause mortality, non-fatal infarction, and urgent revascularization were deemed as our combined clinical endpoint. Results: During adenosine stress testing, 44 of 111 (39.6%) patients exhibited inducible perfusion abnormalities. During a mean follow-up of 1.94 ± 0.65 years, 25 (22.5%) patients reached the combined endpoint (death in n = 2, infarction in n = 3 and urgent revascularization in n = 20). Inducible perfusion defects were associated with higher number of segments with inducible SAS reduction ≥6.5% (χ² = 37.8, AUC = 0.79, 95% CI = 0.71-0.87, p < 0.001). In addition, patients with inducible perfusion defects or SAS impairment exhibited poorer outcomes (AUC_Perf = 0.81 vs. AUC_SAS = 0.74, p = NS vs. each other, and χ² = 30.8, HR = 10.3 and χ² = 9.5, HR = 3.5, respectively, p < 0.01 for both). Conclusion: Purely quantitative strain analysis by fast-SENC during vasodilator stress was related to the diagnosis of ischemia by first-pass perfusion and is non-inferior for the risk stratification of patients with ischemic heart disease. This may bear clinical implications, especially in patients with contraindications for contrast agent administration.

Enoxaparin in patients with primary percutaneous coronary intervention for acute ST segment elevation myocardial infarction

The inhibition of thrombin plays a key role as adjunct therapy in the management of patients with primary percutaneous coronary intervention for ST elevation myocardial infarction. Enoxaparin provides a more predictable and constant level of anticoagulation compared with the current standard unfractionated heparin. The available data from smaller studies and prospective registries suggest that enoxaparin is associated with a reduction in the rate of death and nonfatal reinfarction after primary percutaneous coronary intervention without an increase in bleeding complications. Thus, a large randomized trial is warranted to further evaluate the role of enoxaparin in these patients.

P3554CMR Fast-SENC intramyocardial LV & RV segmental strain helps manage cardioprotective therapy in patients exhibiting cardiotoxicity during cancer treatment

Background

Cardiotoxicity during cancer treatment has become an acknowledged problem of chemotherapy medications and radiation therapy. Limitations of biomarkers and imaging tests such as echocardiography left ventricular ejection fraction (LVEF) hinder early detection of cardiotoxicity and proactive cardioprotective therapy. Once the heart is unable to compensate for subclinical dysfunction, systemic damage and remodeling occurs increasing the potential for heart failure. Fast-SENC segmental intramyocardial strain (fSENC) is a unique cardiac magnetic resonance imaging (CMR) test that regionally detects subclinical intramyocardial dysfunction in 1 heartbeat. This study evaluates the ability of fSENC to detect subclinical cardiotoxicity and manage cardioprotective therapy in cancer patients.

Methods

This single center, prospective Prefect Study was used to evaluate cardiotoxicity and the impact of cardioprotective therapy in Breast Cancer and Lymphoma patients (NCT03543228). fSENC was acquired with a 1.5T MRI and processed with the MyoStrain software to quantify intramyocardial strain. Segmental strain was measured in three short axis scans (basal, midventricular & apical) with 16LV/6RV longitudinal segments & three long axis scans (2-, 3-, 4-chamber) with 21LV/5RV circumferential segments. fSENC CMR was performed before chemotherapy, during and after anthracycline/taxan therapy, at 1 year follow-up, and as needed in between designated follow-up periods. Cardioprotective therapy was offered to patients meeting the definition of cardiotoxicity by the ESC Guidelines on Cardiotoxicity and/or ESMO Clinical Practice Guidelines or those observing a substantial decline in cardiac function. Comparisons were made with paired t-Test with a 95% confidence interval.

Results

Two hundred eight (208) CMRs were performed in fifty-two (52) patients (44 female). Patients had an average (± stdev) age of 53 (15) yrs, BMI of 26 (5) kg/m2; 77% had breast cancer, 23% had Lymphoma. fSENC CMRs required 11 (2) min total exam time. Figure 1 shows bar graphs of the % of normal LV myocardium (e.g. % LV MyoStrain Segments <−17%) at baseline and sequential follow-ups for patients without cardiotoxicity and with cardiotoxicity requiring cardioprotective therapy. Patients observing cardiotoxicity had a statistically significant decline in cardiac function measured by segmental fSENC (p=0.0002) which resolved after cardioprotective therapy.

Figure 1

Conclusion

Segmental fSENC intramyocardial strain detects subclinical cardiotoxicity during chemotherapy and impact of cardioprotective therapy. The ability to serve as a surrogate safety endpoint for chemotherapy or other pharmacological agents, and aid management of cardiotoxicity by serving as a surrogate efficacy endpoint for cardioprotection agents, dosage, and patient compliance may help physicians detect subclinical cardiac dysfunction, and proactively manage cancer patients to avoid early or late heart failure.

P3118CMR Fast-SENC intramyocardial LV & RV segmental strain detects cardiotoxicity during oncology treatment and impact of cardioprotection therapy before echocardiography

Background

The incidence of cardiotoxicity during cancer therapy is underestimated due to limitations of current diagnostic tests. Current biomarkers (BNP, NT-pro-BNP, hs-Troponin, etc.) and imaging calculations (e.g. echocardiography) such as left ventricular ejection fraction (LVEF) are currently included in the guidelines to designate cardiotoxicity during cancer therapy. Unfortunately, these diagnostics identify systemic damage in symptomatic patients after the heart is unable to compensate for regional dysfunction. Fast-SENC segmental intramyocardial strain (fSENC) is a unique cardiac magnetic resonance imaging (CMR) test that regionally detects subclinical intramyocardial dysfunction in 1 heartbeat.

Methods

This single center, prospective Prefect Study was used to evaluate cardiotoxicity and the impact of cardioprotective therapy in Breast Cancer and Lymphoma patients (NCT03543228). fSENC was acquired with a 1.5T MRI and processed with the software to quantify intramyocardial strain. Segmental strain was measured in three short axis scans (basal, midventricular, apical) with 16 LV/6 RV longitudinal segments & three long axis scans (2-, 3-, 4-chamber) with 21 LV/5 RV circumferential segments. fSENC CMR was performed before chemotherapy, during and after anthracycline/taxane therapy, at 1 year follow-up, and as needed in between designated follow-up periods. Cardioprotective therapy was offered to patients meeting the definition of cardiotoxicity by the ESC Guidelines on Cardiotoxicity and/or ESMO Clinical Practice Guidelines or those observing a substantial decline in cardiac function.

Results

Two hundred eight (208) CMRs were performed in fifty-two (52) patients (44 female). Patients had an average (± stdev) age of 53 (15) yrs, BMI of 26 (5) kg/m2; 77% had breast cancer, 23% had Lymphoma. fSENC CMRs required 11 (2) min total exam time. The % of normal fSENC (segmental stain <−17%) with a threshold of 65% showed a sensitivity of 87% and specificity of 89% in detecting cardiotoxicity while echocardiography GLS with a threshold of −17% observed a sensitivity of 20% and specificity of 88%. Figure 1 shows receiver operating characteristic curves for fSENC based on the percent of normal myocardium, and echocardiography global longitudinal strain (GLS) respectively. Global fSENC had substantially lower sensitivity than segmental fSENC despite having higher accuracy than the other global metrics.

Figure 1

Conclusion

Segmental fSENC intramyocardial strain detects subclinical dysfunction due to cardiotoxic response of chemotherapy before other biomarkers and imaging modalities. The ability to detect the subclinical cardiotoxicity of chemotherapy agents, or other pharmacological agents that cause or worsen heart failure, enables proactive prescription of cardioprotective medications to avoid tissue remodeling that precedes systemic cardiac dysfunction and worsening of global measures such as LVEF and current biomarkers.