Myocardial scar characteristics based on cardiac magnetic resonance imaging is associated with ventricular tachyarrhythmia in patients with ischemic cardiomyopathy.

OBJECTIVES: We hypothesized that myocardial scar characterization using cardiac magnetic resonance imaging (CMR) may be associated with the occurrence of ventricular tachyarrhythmia (VT), appropriate implantable cardioverter-defibrillator (ICD) therapy and mortality. BACKGROUND: Since a minority of patients with prophylactic ICD implantation receive appropriate ICD therapy, there is a need for more effective risk stratification for primary prevention in patients with ischemic cardiomyopathy. METHODS AND RESULTS: In 99 patients with ischemic cardiomyopathy, CMR was performed prior to ICD implantation. We assessed if CMR indices (cardiac mass, LVEF) and CMR scar characteristics (infarct core mass, peri-infarction mass and the ratio's between left ventricular mass, infarct core mass and peri-infarction mass) were associated with outcome. The primary endpoint was sustained VT and/or appropriate ICD therapy. The secondary endpoint was all-cause mortality. During a median follow-up of 5.4 years (IQR 4.5-6.6 years), 34 patients reached the primary end-point (17 appropriate ICD shocks) and 26 patients died. In multivariable Cox regression analysis, peri-infarction to core-infarction ratio (HR 2.01, 95%CI: 1.17-3.44, p=0.01) was independently and significantly associated with the primary endpoint, whereas NYHA-class and lower LVEF were not. Conversely, age (HR 1.06, 95% CI: 1.01-1.12, p=0.02) and lower LVEF (HR 0.95, 95% CI: 0.91-1.00, p=0.04) were independently associated with all-cause mortality, mainly due to heart failure. CONCLUSION: A relatively large peri-infarction mass is associated with sustained VT and/or appropriate ICD therapy, whereas age and lower LVEF are associated with mortality. CMR based tissue characterization could aid in the prediction of specific outcome measures and in clinical decision making.

Preoperative assessment of liver function: a comparison of 99mTc-Mebrofenin scintigraphy with indocyanine green clearance test.

BACKGROUND/AIMS: The indocyanine green (ICG) clearance test is the most frequently used test for preoperative assessment of liver parenchymal function but has its limitations. The aim of this study was to investigate the correlation between ICG clearance test and the liver uptake of 99-Technetium-labelled (99mTc)-Mebrofenin (99mTc-Mebrofenin) as measured with hepatobiliary scintigraphy. METHODS: Fifty-four patients were diagnosed as hepatocellular carcinoma (n=9), hilar tumours (n=20) and 25 patients with non-parenchymal tumours including colorectal metastasis (n=15) and miscellaneous tumours (n=10). One day prior to operation, hepatobiliary 99mTc-Mebrofenin scintigraphy was performed after intravenous injection of 85 MBq and the 15-min clearance rate of ICG (ICG-C15) was measured. RESULTS: The mean ICG-C15 was 86.86+/-1.19% (SEM). The mean 99mTc-Mebrofenin uptake rate was 12.87+/-0.52%/min. A significant correlation was obtained between 99mTc-Mebrofenin uptake rate by scintigraphy and ICG-C15 (r=0.73, P<0.0001). The mean clearance capacity of the right liver segments (79.83+/-1.63, range 47.75-95.97%) was larger than that of the left segments (20.24+/-1.55, range 6.51-52.51%). CONCLUSION: 99mTc-Mebrofenin uptake rate as assessed by scintigraphy is an efficient method for determining liver function and correlates well with ICG clearance. At the same time, 99mTc-Mebrofenin scintigraphy provides information of segmental functional liver tissue, which is of additional use when planning liver resection.