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The purpose of this study is to assess the cost-impact of cardiac magnetic resonance imaging (CMR) and its advantages over conventional cardiac catheterization to detect cardiac allograft vasculopathy (CAV) and myocardial inflammation derived from possible rejection in heart transplant (HTx) recipients. A sizable institutions still perform an endomyocardial biopsy (EMB) and coronary artery angiogram (CAG) in routine practice. Non-invasive diagnostic tools such as echocardiography and gene expression profiling have been reported as a possible alternative to EMBs, but its application is limited. Stress echo is a powerful tool for sorting those who require invasive assessment, but it cannot detect ongoing CAV. CMR is free from radiation exposure and allows the visualization of coronary artery narrowing without using contrast agents. We estimated medical care expense needed for rejection and CAV surveillance for HTx recipients at 3 years to 15 year-posttransplant in Japan (n=320), consisting of those with 10 % rejection rate up to 5 years and 20% CAV occurrence thereafter, as a hypothetical cohort. Three models were created. Model-1: Annual investigation using CMR-angiography to assess CAV, and T2W imaging to detect myocardial inflammation. For patients with a suspicion of the development of rejection or CAV, EMBs and CAG are performed. Model-2: Annual evaluation using CAG and EMBs up to 10 years posttransplant. After 10 year-posttransplant, the invasive procedure is done as needed. Model-3: Using echocardiography as a primary modality to detect rejection. CAG biennial and EMBs if any change in echo. If patients never developed rejection or CAV, Model-1 is the least costly with ¥228,800 to 324,860 per patient, whereas Model-2 costs ¥1,064,000 to 2,190,000 and Model-3, ¥445,200 to 689,000, respectively. When we include patients with rejection or CAV according to a hypothetical cohort, Model-1 and Model-3 were equally cost-effective. When we set sensitivity and specificity of CMR and echo as 70%, 80% and 70%, 90%, respectively, Model-1 is most cost-effective with sufficient diagnostic accuracy. Utilization of CMR as an annual follow-up tool in HTx recipients would be beneficial from a viewpoint of medical economics. [ABSTRACT FROM AUTHOR]

Right ventricular (RV) function has been recognized as an important prognostic factor in patients with heart failure. However, previous studies have focused on the global RV function such as RV ejection fraction (RVEF), not on RV contractile pattern. Cardiac magnetic resonance imaging (CMR) is a powerful imaging modality to assess RV morphological change together with its global systolic function.The purpose of this study is to elucidate the difference of RV contractile patterns in various heart diseases with RV dysfunction using CMR. The CMR data obtained from 50 patients with RV dysfunction and 23 control subjects were analyzed.The patients with RV dysfunction were classified into 3 groups according to the etiology of RV dysfunction; RV volume-overload group (Group V, n=16, consisting of those with atrial septal defect), RV-dominant myocyte degeneration (Group M, n=17, consisting of arrhythmogenic right ventricular cardiomyopathy), and pericarditis group (Group P, n=17). The RV longitudinal contractile pattern (FLC: fractional longitudinal change) and the radial contractile pattern (FTC: fractional transverse change) were measured using a 4-chamber view of Cine-CMR. The ratio of transverse to longitudinal contraction (T/L ratio=FTC/FLC) was calculated. Both FLC and FTC significantly decreased in Groups M and P, while Group V showed relatively preserved FTC compared to control subjects. The T/L ratio was significantly lower in Group M than the other groups, while the value tended to be higher in Group V and P than the control (Figure). Impaired transverse contractile pattern as reflected by the reduced T/L ratio may indicate the degeneration of RV myocardium itself, whereas this value tends to be preserved in patients with RV dysfunction due to volume overload. RV contractile pattern may help to understand the disease progression and the underlying cause of RV dysfunction. [ABSTRACT FROM AUTHOR]

In a healthy subject, the left ventricle (LV) generates pressure by twisting, whereas the right ventricle (RV) dose so mainly by longitudinal shortening. Right ventricular (RV) function is recognized as a prognostic predictor in patients with left-sided heart failure. However, previous studies have focused on the global RV function such as RV ejection fraction (RVEF), not on RV morphological change.Cardiac magnetic resonance imaging (CMR) is a powerful imaging modality to assess RV morphological change which enables quantitative analysis of RV longitudinal and transverse shortening together with its global function. The purpose of this study is to investigate whether RV morphology alter even in left-sided heart failure patients with preserved RV global function. We consecutively analyzed CMR findings obtained from 143 patients with left-sided heart failure. Among those, 46 patients who were considered to have a solitary left ventricle dysfunction defined as RVEF>50% were included in the RV morphological analysis. RV-related Fractional longitudinal change (RV-FLC) and transverse change (RV-FTC) were measured. We dichotomized the patients according to the median value of RV-FLC and RV-FTC, and assessed the relationship between the RV and morphology and their LV function. Left ventricular (LV) mass was higher and the age was older in patients with low RV-FLC than in those with high RV-FLC (62.6+/-17.0 vs. 52.7+/-7.5 g/m2, p=0.018, 52.8+/-17.7 vs. 41.4+/-17.8 year-old, p=0.018, respectively). In patients with low RV-FTC, LV end-systolic volume (34.8+/-12.2 vs. 26.9+/-12.7 mL/m2 p=0.019) and RV end-systolic volume (35.8+/-8.0 vs. 28.8+/-10.1 mL/m2, p=0.006) were higher than those with high RV-FTC. In the analysis of patients showing reduced RV function (RVEF<50%), RV contractility was even more dependent on RV transverse shortening. Even in patients with left-sided heart failure and preserved RV global function, RV global function is dependent on RV transverse shortening rather than longitudinal shortening. Detailed investigation of RV contractile pattern using CMR in patients with left-sided heart failure can unveil their underlying RV dysfunction leading prognostic risk-stratification. [ABSTRACT FROM AUTHOR]