Hepatic Flow Redistribution is Feasible in Patients with Hepatic Malignancies Undergoing Same-Day Work-Up Angiography and Yttrium-90 Microsphere Radioembolization.

PURPOSE: To assess the feasibility of performing same-day vascular flow redistribution and Yttrium-90 radioembolization (90Y-RE) for hepatic malignancies. MATERIALS AND METHODS: From November 2015 to February 2019, patients undergoing same-day hepatic flow redistribution during work-up angiography, 99mTechnetium-labeled macroaggregated albumin (99mTc-MAA) SPECT/CT and 90Y microsphere-RE, were recruited. Within 18 h following the delivery of 90Y resin microspheres, an 90Y-PET/CT study was performed. According to patients' vascular anatomy, flow redistribution was performed by microcoil embolization of extrahepatic branches (group A), intrahepatic non-tumoral vessels (group B) and intrahepatic tumoral arteries (group C). The accumulation of 99mTc-MAA particles and microspheres in the redistributed areas was qualitatively evaluated using a 5-point visual scale (grade 1 = < 25% accumulation; grade 5 = 100% accumulation). Differences in the distribution of microspheres among groups were assessed with Mann-Whitney U test. RESULTS: Twenty-two patients were treated for primary (n = 17) and secondary (n = 5) hepatic malignancies. The MAA-SPECT/CT showed uptake in all the redistributed areas. Regarding the accumulation of microspheres within the redistributed segments in all the groups, perfusion patterns were classified as 2 in 1 case, 4 in 6 cases and 5 in 15 cases. No statistically significant differences were observed between groups A and B-C (U value = 34, p = 0.32) and between groups B and C (U value = 26, p = 0.7). Mean predicted absorbed doses by the tumoral and normal hepatic tissues were 163.5 ± 131.2 Gy and 60.4 ± 69.3 Gy, respectively. Mean total procedure time (from work-up angiography to 90Y delivery) was 401 ± 0.055 min. CONCLUSION: Performing same-day redistribution of the arterial hepatic flow to the target and 90Y-microsphere delivery is feasible in the treatment of liver tumors. Clinical Trials Registry NCT03380130.

Safety of regadenoson for vasodilation in cardiac MRI stress tests. / Seguridad del empleo de regadenosón como fármaco vasodilatador en resonancia magnética cardíaca de estrés.

OBJECTIVE: To determine the safety of regadenoson for vasodilation in cardiac MRI stress tests to detect myocardial ischemia. MATERIAL AND METHODS: We retrospectively analyzed cardiac MRI studies done in 120 patients (mean age, 67±11.6 years; 88 men) with suspected ischemic heart disease or known coronary disease who had clinical indications for cardiac MRI stress tests. All studies were done on a 1.5 T scanner (MAGNETOM Aera, Siemens Healthineers) using regadenoson (5ml, 0.4mg) for vasodilation. We recorded cardiovascular risk factors, medications, and indications for the test as well as vital signs at rest and under stress and the symptoms and adverse effects induced by the drug. RESULTS: No symptoms developed in 52.6% of patients. The most common symptoms were central chest pain (25%) and dyspnea (12%). At peak stress, the mean increase in heart rate was 23.9±11.4 beats per minute and the mean decreases in systolic and diastolic blood pressure were 7.1±18.8mmHg and 5.3±9.2mmHg, respectively (p <0.001). The response to regadenoson was less pronounced in obese and diabetic patients. The increase in heart rate was greater in symptomatic patients (27.4±11.2 bpm vs. 20.6±10.7 bpm in asymptomatic patients, p=0.001). No severe adverse effects were observed. CONCLUSION: Regadenoson is well tolerated and can be safely used for cardiac MRI stress tests.

Cardiac magnetic resonance imaging myocardial perfusion reserve index in heart transplant patients. / Valoración del índice de reserva de perfusión miocárdica por resonancia magnética en pacientes con trasplante cardíaco.

OBJECTIVE: To compare the myocardial perfusion reserve index (MPRI) measured during stress cardiac magnetic resonance imaging (MRI) with regadenoson in patients with heart transplants versus in patients without heart transplants. MATERIAL AND METHODS: We retrospectively compared 20 consecutive asymptomatic heart transplant patients without suspicion of microvascular disease who underwent stress cardiac MRI with regadenoson and coronary computed tomography angiography (CTA) to rule out cardiac allograft vasculopathy versus 16 patients without transplants who underwent clinically indicated stress cardiac MRI who were negative for ischemia and had no signs of structural heart disease. We estimated MPRI semiquantitatively after calculating the up-slope of the first-pass enhancement curve and dividing the value obtained during stress by the value obtained at rest. We compared MPRI in the two groups. Patients with positive findings for ischemia on stress cardiac MRI or significant coronary stenosis on coronary CTA were referred for conventional coronary angiography. RESULTS: More than half the patients remained asymptomatic during the stress test. Stress cardiac MRI was positive for ischemia in two heart transplant patients; these findings were confirmed at coronary CTA and at conventional coronary angiography. Patients with transplants had lower end-diastolic volume index (59.3±15.2 ml/m2 vs. 71.4±15.9 ml/m2 in those without transplants, p=0.03), lower MPRI (1.35±0.19 vs. 1.6±0.28 in those without transplants, p=0.003), and a less pronounced hemodynamic response to regadenoson (mean increase in heart rate 13.1±5.4 bpm vs. 28.5±8.9 bpm in those without transplants, p <0.001). CONCLUSION: Stress cardiac MRI with regadenoson is safe. In the absence of epicardial coronary artery disease, patients with heart transplants have lower MPRI than patients without transplants, suggesting microvascular disease. The hemodynamic response to regadenoson is less pronounced in patients with heart transplants than in patients without heart transplants.