Tissue characterization and myocardium strain by cardiac magnetic resonance imaging in the early detection of anthracycline cardiotoxicity

Background

Cardiotoxicity (CT) remains an important cause of morbidity and mortality in patients with lymphomas treated with anthracyclines. Current strategies for early detection of CT during chemotherapy are not yet fully established.

Purpose

To evaluate the performance of cardiac magnetic resonance with T1 mapping and myocardium strain by feature tracking during chemotherapy in detecting anthracycline CT in patients with lymphoma.

Methods

From June 2017 to March 2019, patients with lymphoma planned to start chemotherapy with anthracyclines were evaluated by a cardiologist to check the eligibility criteria. At baseline (Time 1), at the end of 3° cycle (Time 2) and 30 days after the final cycle (Time 3), patients were evaluated through cardiac biomarkers, electrocardiogram and cardiac magnetic resonance (CMR). Strain, MapT1 and extracellular volume (ECV) were evaluated in all patients. CT was defined as drop of the left ventricular fraction (LVEF) >10% or LVEF decrease below 50%. A p value <0.05 was considered statistically significant.

Result

We included 48 patients, mean age was 45.32 (± 17.84) years-old and 25 (52.1%) were female. The prevalence of hypertension, diabetes and dyslipidemia was 18.8%, 10.4% and 10.4%, respectively. CT was diagnosed in 13 patients (27%). At baseline, there was no difference between cardiotoxicity group (CTG) and no cardiotoxicity group (nCTG) in CMR diastolic volume, systolic volume, nativeT1 map and global longitudinal strain (GLS), respectively (116 [103.6–138.1]ml vs 136.3 [115.7–173.8], p=0.069), (46 [38.0–58.5] ml vs 63.0 [44.5–74.2, p=0.069), (1540.6 [1478.3–1591.1]ms vs 1514.8 [1487.5–1786.3]ms, p=0.568) and (−15.94±2.91% vs −14.84±2.65%, p=0.243). Regarding the others CMR parameters, we showed that comparing CTG patients with nCTG patients at Time 3, systolic volumes were higher (54.8 [45.0–67.0] ml vs 78.51 [53.9–96.3] ml, p=0.007), right ejection fraction was lower (53.41±9.73% vs 46.29±3.93%, p=0.002), LVEF was lower (58.7±5.69% vs 46.67±8.12%, p<0.001) and GLS and radial strain were also reduced (−13.92±1.76% vs −12.44±2.7%, p=0.043) and (22.9 [21.18–27.43]% vs 19.84 [17.12–21.73], p=0.017), respectively. We did not observe any difference between groups in the native T1 map between groups at Time 2 and 3 1537.75 (1493.76–1589.72)ms vs 1601.99 (1501.12–1673.44)ms (p 0.383) and 1538.43 (1479.03–1633.6)ms and 1612.85 (1522.74–1638.34) ms (p=0.289). Similarly, the ECV value was no difference between groups at Time 2 and 3 (25.17 [23.62–32.83]% vs 24.42 [22.75–27.47], p=0.281 and 27.5 [23.59 - 31,9]% vs 27.2 [23.84–28.47]%, p=0.529, respectively).

Conclusions

Cardiotoxicity is a frequent complication in anthracycline treated patients. CMR evaluation, through analysis of volumes, ejection fraction and strain might early identify these patients, allowing prevention strategies to be initiated to improve cardiovascular outcomes.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Fundação de Apoio a pesquisa do estado de São Paulo - FAPESP

Prognostic value of noninvasive combined anatomic/functional assessment by cardiac ct in patients with suspected coronary heart disease

Background

Noninvasive evaluation of patients with stable angina is preferable over invasive testing if it leads to similar patient outcome. The combination of coronary angiography and vasodilator challenge myocardial perfusion imaging by computed tomography allows fast, comprehensive assessment of patients with suspected coronary heart disease.

Purpose

To compare the long-term prognostic value of combined computed tomography angiography (CTA) and myocardial CT perfusion imaging (CTP) with invasive coronary angiography (ICA) and single photon emission tomography (SPECT) in patients with suspected hemodynamically significant coronary heart disease.

Methods

At 16 centres, 381 patients were followed for major adverse cardiac events (MACE) for the CORE320 study. All patients underwent coronary CTA, CTP, and SPECT before ICA. Prognostic performance according binary results (normal/abnormal) was assessed by 5-year major cardiovascular events (MACE) free survival and area under the receiver-operating-characteristic curve (AUC).

Results

Follow up beyond 2-years was available in 323 patients. MACE-free survival rate was greater among patients with normal combined CTA/CTP findings compared to ICA/SPECT: 85 vs. 80% (95% confidence interval [CI] for difference 0.1, 11.3) though event-free survival time was similar (4.54 vs. 4.37 years, 95% CI for difference: 0.03, 0.36). Abnormal results by combined CTA/CTP was associated with 3.83 years event-free survival vs. 3.66 years after abnormal combined ICA/SPECT (95% CI for difference: 0.05, 0.39, CI −1.0, 11.1) (Figure). Predicting MACE by AUC also was similar: 65 vs. 65 (difference 0.1; 95% CI: −4.6, 4.9). When MACE was restricted to death, myocardial infarction, or stroke, AUC for CTA/CTP was 66 vs. 61 by ICA/SPECT (difference 5.1; 95% CI: −7.1, 12.9).

Conclusions

Combined CTA/CTP yield similar 5-year prognostic performance as joined ICA/SPECT assessment in patients presenting with suspected coronary heart disease and thus may represent a fast, non-invasive alternative to the traditional diagnostic approach.

Figure 1. 5-year event-free survival

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): National Institutes of Health

T1 mapping for myocardial tissue evaluation in patients with ischemia and stable coronary artery disease: MASS V-Trial Study Group

Background

T1 mapping is a magnetic resonance imaging (MRI) technique that enables the identification of myocardial structural changes during acute ischemic injury. However, it is not known whether these structural changes are present in patients with chronic effort induced ischemia.Thus, we sought to document the possible T1 mapping changes in chronic coronary artery disease (CAD) patients with documented myocardial ischemia.

Methods

Multivessel CAD patients from MASS V Trial with indication of myocardial revascularization, were evaluated for the presence of ischemia by myocardial scintigraphy. MRI with T1 mapping was performed in all patients. Based on the results of the scintigraphy, the myocardial segments were identified as ischemic and non-ischemic segments. The corresponding segments of scintigraphy and MRI were compared in relation to native T1 map (NT1), post-contrast T1 (CAT1) and extracellular volume (ECV).

Results

Of the 720 myocardial segments analyzed, there were 161 ischemic and 559 non-ischemic segments. Comparing ischemic vs non-ischemic segments, respectively, NT1 was 1022.7 (980.0–1052.0) versus 1029.3 (985.0–1066.3), p=0.57, ECV results were 25.4 (24.0–28.1) versus 26.4 (25.3–29.9), p=0.75 and CAT1 results were 492 (461.9–515.4) versus 488 (469.2–521.7), p=0.09. Myocardial segments supplied by obstructive coronary arteries were compared to those supplied by non-obstructive coronary arteries in relation to NT1 and ECV. NT1 values in obstructive and non-obstructive territories were, respectively, 1024.7 (998.5–1043.5) versus 1036.8 (1008.6–1046.9), p=0.30 and ECV results were 26.8 (24.4–29.9) versus 26.8 (24.4–30.0), p=0.90.

Conclusion

In this study, MRI identified structural similarities between chronic ischemic myocardium compared to the non-ischemic myocardium. This finding supports myocardial tissue stability in the presence of stress induced ischemia.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Zerbini Foundation and also by the FAPESP (2011/ 20876-2)