Contemporary Role of Cardiac Magnetic Resonance in the Management of Patients with Suspected or Known Coronary Artery Disease

The association between cardiac T2*BOLD and quantitative flow ratio (QFR) in the diagnosis of stenotic coronary arteries in patients with multi-vessel coronary artery disease

BACKGROUND

T2*BOLD is based on myocardial deoxyhemoglobin content to reflect the state of myocardial oxygenation. Quantitative flow ratio is a tool for assessing coronary blood flow based on invasive coronary angiography.

PURPOSE

This study aimed to evaluate the correlation between T2*BOLD and QFR in the diagnosis of stenotic coronary arteries in patients with multi-vessel coronary artery disease.

METHODS

Fifty patients with MVCAD with at least 1 significant coronary artery stenosis (diameter stenosis > 50%) and 21 healthy control subjects underwent coronary angiography combined with QFR measurements and cardiovascular magnetic resonance (CMR). QFR ≤ 0.80 was considered to indicate the presence of hemodynamic obstruction.

RESULTS

Totally 60 (54%) obstructive vessels had hemodynamic change. Between stenotic coronary arteries (QFR ≤ 0.8) and normal vessels, T2*BOLD showed AUCs of 0.97, 0.69, and 0.91 for left anterior descending (LAD), left circumflex (LCX) and right coronary (RCA) arteries and PI displayed AUCs of 0.89, 0.77 and 0.90 (all p > 0.05, except for LAD). The AUCs of T2*BOLD between stenotic coronary arteries (QFR > 0.8) and normal vessels were 0.86, 0.72, and 0.85 for LAD, LCX and RCA; while, PI showed AUCs of 0.93, 0.86, and 0.88, respectively (p > 0.05). Moreover, T2*BOLD displayed AUCs of 0.96, 0.74, and 0.91 for coronary arteries as before between coronary arteries with stenosis (QFR ≤ 0.8 and > 0.8), but the mean PI of LAD, LCX and RCA showed no significant differences between them.

CONCLUSION

T2* BOLD and QFR have good correlation in diagnosing stenotic coronary arteries with hemodynamic changes in patients with stable multi-vessel CAD. T2* BOLD is superior to semi-quantitative perfusion imaging in analyzing myocardial ischemia without stress.

Role of feature tracking cardiac magnetic resonance imaging in early detection of cardiac dysfunction in β-thalassemia patients recovered from COVID-19: A cross-sectional study

Background and Aims

β-Thalassemia patients may have cardiac complications due to iron overload, which puts them at higher risk of cardiac complications induced by coronavirus disease 2019 (COVID-19) compared with the normal population. The present study aims to evaluate early cardiovascular complications following iron overload in β-thalassemia patients who had early recovery from COVID-19 by cardiac magnetic resonance imaging (MRI) and feature-tracking technique.

Methods

Thirty-two confirmed COVID-19-recovered β-thalassemia cases were evaluated within 3 weeks to 3 months after a positive reverse-transcriptase polymerase chain reaction COVID-19 test. Both the heart and liver of all patients were examined using cardiac MRI.

Results

We analyzed 32 patients with mean age of 32.84 ± 6.45 years at baseline. Left ventricular global strain values were significantly associated with myocardial T2*. A cut-off value of -15.08% for global longitudinal strain (GLS) with sensitivity and specificity of 90% and 61.1% (p = 0.017), 32.33% for global radial strain (GRS) with sensitivity and specificity of 80% and 94.4% (p = 0.001) and -16.21 for global circumferential strain (GCS), with sensitivity and specificity of 80% and 89.9% (p = 0.013) may indicate cardiac iron overload.

Conclusion

GLS, GRS, and GCS were significantly decreased in patients with myocardial T2* <20 ms (iron overload), while no significant change was observed in the right and left ventricular ejection fraction (RV- and LVEF). Cardiac MRI feature-tracking may be helpful in the early detection of cardiac complications resulting from iron overload in β-thalassemia patients who had early recovery from COVID-19.