Cardiac allograft vasculopathy after heart transplantation: electrocardiographically gated cardiac CT angiography for assessment.

PURPOSE: To evaluate the diagnostic accuracy of cardiac computed tomographic (CT) angiography without the use of ß-blockers compared with that of invasive angiography for the detection of cardiac allograft vasculopathy (CAV) in heart transplant recipients. MATERIALS AND METHODS: The study was approved by the research ethics committee and informed consent was obtained. Heart transplant recipients (n = 138) scheduled for routine invasive angiography were prospectively enrolled to undergo CT to evaluate coronary artery calcification and retrospectively gated cardiac CT angiography with a 64-section scanner. The cardiac CT angiographic images were systematically analyzed for image quality. Degree of CAV was assessed by using a 15-coronary segments model. The area under the receiver operating characteristic curve, sensitivity, specificity, and negative and positive predictive values of cardiac CT angiography for detection of CAV with any degree of stenosis and greater than or equal to 50% stenosis were calculated. RESULTS: Coronary artery calcification was absent in 82 patients, five (6%) of whom had CAV with 50% or more stenosis. Interpretable image quality was obtained in 130 (96%) of the 136 patients who completed the study and 1900 (98%) of 1948 segments. At the patient level, cardiac CT angiography had an area under the receiver operating characteristic curve, sensitivity, specificity, and positive and negative predictive values of 0.880 (95% confidence interval: 0.819, 0.941), 98%, 78%, 77%, and 98%, respectively, for diagnosis of CAV with any degree of stenosis, but for CAV with 50% or more stenosis, the corresponding values were 0.942 (95% confidence interval: 0.885, 1.000), 96%, 93%, 72%, and 99%, respectively. None of the 61 patients with normal cardiac CT angiographic results had CAV on the basis of invasive angiographic images. CONCLUSION: The study results show that cardiac CT angiography compares favorably with invasive angiography in detecting CAV in heart transplant recipients and may be a preferable screening technique because of its noninvasive nature. The absence of coronary artery calcification alone is not reliable enough for excluding CAV.

Volumetric intravascular ultrasound assessment of mechanisms and results of stent expansion in heart transplant patients.

BACKGROUND: Percutaneous coronary intervention with stent placement for the treatment of patients with cardiac allograft vasculopathy is common, but data regarding stent behavior in this setting is lacking. OBJECTIVES: We investigated mechanisms and potential differences in stent expansion among transplant patients vs. patients with native coronary artery atherosclerotic disease ("controls"). METHODS: We compared pre- and poststent intravascular ultrasound in 12 transplant patients (17 lesions) and 33 control patients (34 lesions) matched according to age (60.1 ± 9.2 years), diabetes mellitus, and lesion location. Planar and volumetric analysis was conducted for every 1 mm at the lesion site as well as the first 5 mm proximal and distal to the stent edge. Focal stent expansion was defined as minimum stent area (MSA) divided by mean reference lumen area. Diffuse stent expansion was defined as mean stent area divided by mean reference lumen area. RESULTS: Transplant patients had more plaque than "controls" prestenting, but similar MSA and focal and diffuse stent expansion afterwards. The increase in mean lumen area correlated with the increase in mean vessel area in both groups, transplant (R = 0.64, P = 0.008) and controls (R = 0.70, P < 0.0001), but correlated inversely with changes in mean plaque area only in the transplant group (R = 0.55, P = 0.027). There were no differences in calcification between the two groups and no axial plaque distribution from the lesion into the reference segments in either group. CONCLUSIONS: The mechanism of stent expansion in transplant vasculopathy appears to be similar to de novo atherosclerosis-i.e., mainly vessel expansion to achieve similar acute results.

Functional assessment of donor and recipient left atrium in heart transplant patients using full-volume three-dimensional echocardiography.

BACKGROUND: Atrial function plays an important role in many cardiac conditions, how recipient and donor compartments of left atrium (LA) of transplanted hearts differentially contribute to overall LA function in transplanted hearts has not been described. We tested whether three-dimensional transthoracic echocardiography (3DE) could be used to calculate these compartment-specific atrial functions. METHODS AND RESULTS: We analyzed 3DE images of 22 consecutive transplant patients who had diagnostic imaging quality (ages 59 ± 16 years) using TomTec Research Arena. The contour of the recipient and total LA were traced frame by frame, and the donor LA volume was calculated as the difference of the total LA volume minus the recipient LA volume. The LA ejection fractions of total LA, donor LA, and recipient LA were also calculated as (LA atrial end-diastolic volume - LA atrial end-systolic volume)/LA atrial end-diastolic volume of each compartment. Interobserver variability of LA volumes for the total, recipient, and donor compartments were 5.6 ± 2.4, 5.4 ± 2.0, and 9.3 ± 3.2 mL, respectively (n = 11). The donor LA ejection fraction was higher than that of recipient (41 ± 18% vs. 30 ± 14%, P = 0.013). When the patients were categorized as asymptomatic (New York Heart Association functional class [NYHA] functional class I) and symptomatic (NYHA functional class II-III), indexed donor LA atrial end-diastolic volume was significantly lower in asymptomatic patients as compared with symptomatic patients. CONCLUSIONS: Compartment-specific LA volumes can be calculated in orthotopic heart transplant patients using full-volume 3DE. Our findings may suggest that unique contribution of each LA compartment of transplanted hearts toward the symptoms of these patients.

Usefulness of dual-source computed tomography for the evaluation of coronary arteries in heart transplant recipients.

BACKGROUND: Heart transplant recipients require serial assessment of coronary arteries due to a risk of cardiac allograft vasculopathy or atherosclerosis. Currently available non-invasive imaging methods are of a limited value for the detection of coronary stenoses, and thus invasive coronary angiography (ICA) is recommended. AIM: We evaluated diagnostic accuracy and clinical usefulness of dual-source computed tomography (DSCT) as a potential alternative to ICA for the detection of coronary stenoses. METHODS: DSCT was performed in 20 consecutive heart transplant recipients (15 males, mean age 47.5 years) who were scheduled for ICA. Exclusion criteria included renal dysfunction with creatinine clearance <45 mL/min and lack of patient consent. All examinations were performed using a first generation dual-source scanner and a retrospectively ECG-gated protocol. Data sets were routinely reconstructed in best-systolic and best-diastolic phases. We evaluated presence of a >50% stenosis in a vessel with a diameter of >1.0 mm, image quality of each segment, and radiation dose delivered to the patient. Sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy were calculated in per segment, per vessel, and per patient analyses, with ICA considered the reference method. RESULTS: All DSCT and ICA examinations were diagnostic and performed without any complications. Mean heart rate was 85 bpm (range 63-114), and was stable in 85% of patients. Significant stenoses (>50%) were diagnosed by DSCT in 4 of the 287 segments, and these findings were confirmed by ICA in 2 segments. Sensitivity, specificity, and diagnostic accuracy were: (1) in the per segment analysis, 100%, 99%, and 99%, respectively, for the left coronary artery; and 100% each for the right coronary artery; (2) 100%, 97%, and 97%, respectively, in the per vessel analysis; and (3) 100%, 94%, 95%, respectively, in the per patient analysis. In diastolic reconstructions, right coronary segments were significantly more commonly nondiagnostic than left coronary segments (25% vs. 11.5%, p = 0.003). In contrast, right coronary segments showed better quality than left coronary segments in systolic reconstructions (63.5% vs. 42.2%, p <0.001). Mean effective radiation dose was 12.7 (range 5.4-18.7) mSv. CONCLUSIONS: DSCT is a clinically useful alternative to invasive coronary angiography for excluding significant coronary stenoses in heart transplant recipients. The negative predictive value of this modality is very high. Sensitivity, specificity and diagnostic accuracy is acceptably high. Imaging of coronary arteries in patients with high heart rates in technically feasible, but require modifications of routine exam protocol. Using of modern prospectively ECG-triggered protocols is not reccommended.

Role of echocardiography in the ventricular assessment of the transplanted heart versus heart rejection.

BACKGROUND: Heart transplantation is an alternative for individuals with end-stage heart disease. However, episodes of heart rejection (HR) are frequent and increase morbidity and mortality, requiring the use of an accurate non-invasive exam for their diagnosis, since endomyocardial biopsy (EMB) is not a complication-free procedure. OBJECTIVE: To compare the parameters obtained by use of Doppler echocardiography in a group of transplanted patients with HR (TX1) and another group of transplanted patients without rejection (TX0), having as reference a control group (CG) and observing the behavior of the left ventricular systo-diastolic function expressed as the myocardial performance index (MPI) METHODS: Transthoracic echocardiographies were performed from January 2006 to January 2008 to prospectively assess 47 patients divided into three groups: CG (36.2%); TX0 (38.3%); and TX1 (25.5%). The MPI was compared between the groups, and data were analyzed by use of Fisher exact test and nonparametric Kruskal-Wallis test, both with significance level of 5%. RESULTS: The groups did not differ regarding age, weight, height, and body surface. When compared to GC, TX0 and TX1 showed a change in the left ventricular systo-diastolic function, expressed as an increase in MPI, which was greater in TX1 [0.38 (0.29 - 0.44); 0.47 (0.43 - 0.56); 0.58 (0.52 - 0.74), respectively; p < 0.001]. CONCLUSION: Echocardiography was a very accurate test to detect changes in the systo-diastolic function of the transplanted heart; however, it did not prove to be reliable to replace BEM in the safe diagnosis of HR.

Follow-up examination of 12 heart transplant recipients with cardiac CT.

OBJECTIVE: The aims of this study were to observe the changes of a transplanted heart with cardiac computed tomography (CT) and to evaluate the clinical application of the examination. METHODS: Cardiac CT was performed on 12 heart transplant recipients, of which 4 cases were also examined by echocardiography. Coronary arteries, the cardiac chamber, and the wall were shown with three-dimensional imaging techniques, and their changes were analyzed and discussed. RESULTS: Twelve heart transplant recipients were successfully examined by CT. All transplanted hearts were found with good anastomosis at the great vessels and atria. Coronary allograft vasculopathy was found in 7 cases, of which 4 cases were found with ventricular dilation or ventricular septum thickening and 1 with tricuspid regurgitation. Ventricular dilation was found in other 3 cases, of which 1 was found with ventricular septum thickening and 1 with tricuspid regurgitation. No abnormality was found by cardiac CT in the rest 2 cases, which were found with mitral regurgitation by echocardiography. CONCLUSION: Cardiac CT can clearly and directly display the changes in the shape of a transplanted heart and coronary artery abnormalities. It will become an ideal noninvasive follow-up method for the heart transplant recipients.

Clinical, haemodynamic and echocardiographic features of early cardiac graft dysfunction.

BACKGROUND: The main cause of early death after heart transplantation (HTx) is so-called early primary or secondary graft failure (GF). The risk of profound GF has not declined in the past decade, as the consequence of the liberalisation of donor acceptance criteria because of the scarcity of donors. It is therefore important to try to diagnose graft failure and recognise the mechanisms of early graft dysfunction. AIM: To establish haemodynamic and echocardiographic criteria of early GF to define patients who should be considered for assist device support or re-transplantation. METHODS: Between January 2000 and March 2009, 116 HTx patients were studied. On the basis of echocardiography and continuous invasive monitoring, three groups were identified: (1) The true graft failure group (GF) consisted of 46 patients; (2) The latent right ventricular (RV) dysfunction group (RV-D) consisted of 25 patients with small left ventricular (LV) chamber (〈 39 mm) and RV ejection fraction (RVEF) 〈 50%; (3) The control group consisted of 45 consecutive HTx patients without any haemodynamic complications. RESULTS: Postoperatively, only the GF group required large doses of norepinephrine (〉 0.3 µmg/kg/min) and inhalative NO (40 ppm). Nevertheless, right and left filling pressures were significantly higher than in the controls (right 12 ± 3.6 vs. 9.0 ± 2 and left atrial pressure 13.0 ± 3.2 vs. 9.6 ± 2 mm Hg, both p 〈 0.001). Cardiac index was significantly smaller (2.9 ± 0.7 vs. 3.7 ± 0.9, p 〈 0.001) but neither pulmonary artery pressure (29.5 ± 6 vs. 29.7 ± 7 mm Hg) nor transpulmonary gradient (6 ± 5 vs. 5.1 ± 5 mm Hg) nor pulmonary vascular resistance (273 ± 97 vs. 287 ± 144 dyn × s × cm-5) differed significantly from those of the control group. In the GF group, LV end diastolic dimension (LVEDD) was significantly smaller and function poorer than in controls (39.8 ± 5 vs. 44.4 ± 5 mm, respectively, p = 0.001). RV function was also significantly worse (RVEF 42.2 ± 14% vs. 56.0 ± 9%), respectively, p = 0.001), whereas RV dimension did not differ significantly. Mechanical support after failure of the initial medical treatment was necessary in 37% of patients; 29 (63.0%) patients from the GF group died, the cause of death being sepsis with multi-organ failure. In the RV-D group, remodelling was quite similar but LVEF was excellent and maximal systolic velocity from the posterior wall was significantly higher than in GF. No death occurred. CONCLUSIONS: True early GF represents a grave haemodynamic situation with high mortality. Bedside echocardiography helps to distinguish between latent RV dysfunction and true GF.

Assessment of cardiac allograft vasculopathy in cardiac transplantation: experience of a Brazilian center.

BACKGROUND: Cardiac transplantation continues to be the treatment of choice for heart failure refractory to optimized treatment. Two methods have high sensitivity for diagnosing allograft rejection episodes and cardiac allograft vasculopathy (CAV), important causes of mortality after transplantation. OBJECTIVE: To assess the relationship between intravascular ultrasound (IVUS) results and endomyocardial biopsy (BX) reports in the follow-up of patients undergoing cardiac transplantation in a Brazilian reference service. METHODS: A retrospective epidemiological observational study was carried out with patients undergoing orthotopic cardiac transplantation from 2000 to 2009. The study assessed the medical records of those patients and the results of the IVUS and BX routinely performed in the clinical post-transplant follow-up, as well as the therapy used. RESULTS: Of the 77 patients assessed, 63.63% were males, their ages ranging from 22 to 69 years. Regarding the IVUS results, 33.96% of the patients were classified as Stanford class I, and 32.08%, as Stanford class IV. Of the 143 BX reports, 51.08% were 1R, and 0.69%, 3R. The Quilty effect was described in 14.48% of the BX reports. All patients used antiproliferative agents, 80.51% used calcineurin inhibitors, and 19.48% used proliferation signal inhibitors. CONCLUSION: The assessment of cardiac transplant patients by use of IVUS provides detailed information for the early and sensitive diagnosis of CAV, which is complemented by histological data derived from BX, establishing a possible causal relationship between CAV and humoral rejection episodes.

Ex vivo coronary angiography of a donor heart in the organ care system.

The international demand for donor hearts for transplantation is steadily increasing. Thus, longer transportation distances and explantation from sites with limited abilities for preexplantation diagnostics have to be considered. The development of the Organ Care System® (OCS) (TransMedics, Andover, MA, USA) may extend the extracorporeal period, with the possibility to constantly evaluate and interact during organ transport. One of the potential advantages of the OCS® is the ability to even perform coronary angiography of the donor heart, if a preexplantation angiography evaluation is not possible at the donor hospital and if significant evidence for coronary artery disease in the donor heart becomes known, because of the donor's medical history or after palpation of sclerotic coronary ostia. In this report, we present the first ex vivo coronary angiography evaluation of a potential donor heart that was performed in the OCS®. Upon explantation of the donor heart, sclerosis of the left coronary artery was palpated. After reaching the implantation site, a coronary angiography was performed by placing the OCS® on a catheterization table and inserting a 6F sheath into the access site of the OCS®. A 6F guide catheter was used to intubate the left coronary ostium. Injection of contrast agent led to strong contrast for visualization of the left coronary system. This procedure allowed sufficient assessment of the coronary arteries, which showed a slight diffuse sclerosis without any significant stenosis. This report demonstrates the advantage of the OCS® in the complex assessment of donor hearts after explantation. While the donor heart is still in the OCS®, not only is it possible to measure metabolic parameters and pressures, but even coronary angiography is feasible. With the increasing international demand for donor organs, such ex vivo examinations might play a more important role, because longer transportation distances can be accepted and organs from suboptimal donors without preexplantation diagnostics may be considered at donor sites with limited diagnostic options.

Assessment of left ventricular parameters in orthotopic heart transplant recipients using dual-source CT and contrast-enhanced echocardiography: comparison with MRI.

OBJECTIVES: To establish the accuracy and reliability of cardiac dual-source CT (DSCT) and two-dimensional contrast-enhanced echocardiography (CE-Echo) in estimating left ventricular (LV) parameters with respect to cardiac magnetic resonance imaging (CMR) as the reference standard. METHODS: Twenty-five consecutive heart transplant recipients (20 male, mean age 62.7±10.4 years, mean time since transplantation 8.1±5.9 years) were prospectively recruited. Two blinded readers independently assessed LV ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), and stroke volume (SV) for each patient after manual tracing of the endo- and epicardial contours in DSCT, CE-Echo and CMR cine images. Student's t-test for paired samples for differences, and Bland and Altman plots and Lin's concordance-correlation coefficients (CCC) for agreement were calculated. RESULTS: There was no statistical difference between left ventricular parameters determined by DSCT and CMR. CE-Echo resulted in significant underestimation of left ventricular volumes (mean difference EDV: 15.94±14.19 ml and 17.1±17.06 ml, ESV: 8.5±9.3 and 7.32±9.14 ml with respect to DSCT and CMR), and overestimation of EF compared with the cross-sectional imaging modalities (3.78±8.47% and 2.14±8.35% with respect to DSCT and CMR). Concordance correlation coefficients for LV parameters using DSCT and CMR were higher (CCC≥0.75) than CCC values observed between CE-Echo and DSCT- or CMR-derived data (CCC≥0.54 and CCC≥0.49, respectively). Interobserver agreement was higher for DSCT and CMR values (CCC≥0.72 and CCC≥0.87, respectively). CONCLUSION: In orthotopic heart transplantation cardiac DSCT allows accurate and reliable estimation of LV parameters compared with CMR, whereas CE-Echo seems to be insufficient to obtain precise measurements.

Two-dimensional speckle tracking echocardiography in heart transplant patients: three-year follow-up of deformation parameters and ejection fraction derived from transthoracic echocardiography.

AIMS: Non-invasive diagnosis of allograft dysfunction is a major objective in the management of heart transplant (HTX) recipients. Speckle tracking echocardiography (STE) permits comprehensive assessment of myocardial function. It is well established that deformation indices are reduced in HTXs when compared with control subjects. However, it is unclear if the reduction in strain is a chronic progressive phenomenon in HTX patients. Method and results Follow-up transthoracic echocardiography (TTE) was performed 3 years after initial TTE in 20 'healthy' HTX patients (13.2 years post-transplantation at time of follow-up) with normal ejection fraction and angiographically ruled out allograft vasculopathy. Grey-scale apical views were recorded and stored for automated offline speckle tracking (EchoPAC 7.0, GE) of the 16 segments of the left ventricle. Strain analysis was performed in 320 segments 34.3 ± 3.7 months after initial assessment. Automated tracking of myocardial deformation for determination of longitudinal systolic strain was not possible in 24 (7.5%) segments at baseline and in 32 (10.0%) segments at follow-up (P = ns). The left ventricular ejection fraction (LVEF) was 61.9 ± 8.1% at the initial examination vs. 62.8 ± 5.8% 3 years afterwards (P = ns). Global longitudinal peak systolic strain was -14.0 ± 4.0 vs. -14.4 ± 2.8%, respectively (P = ns). CONCLUSION: This is the first study describing follow-up deformation parameters in HTX patients undergoing STE. 'Healthy' HTX patients with normal coronary arteries and normal ejection fractions showed no deterioration of longitudinal strain values 3 years after the initial assessment. Apparently, deformation values remain stable over the years as long as the LVEF is preserved.

Coronary calcifications detected by computed tomography are not markers of cardiac allograft vasculopathy.

BACKGROUND: Cardiac allograft vasculopathy (CAV) still limits survival after heart transplantation. Currently available noninvasive tests are of inferior value to detect CAV, and thus invasive coronary angiography (ICA) is frequently performed. Cardiac dual-source computed tomography calcium scoring (DSCTCS) offers the possibility to detect coronary calcifications, which might serve as a noninvasive marker of CAV. This study sought to evaluate its clinical feasibility. METHODS: One hundred sixty-one patients (130 men; 31 women; mean age: 50.5±12.1 years) underwent DSCTCS 1±2 days before annual routine ICA. Mean posttransplant time was 73.7±49.6 months. The results of DSCTCS were compared with ICA. RESULTS: In 100 patients (85 men; 15 women; mean age: 51.5±12.3 years), coronary calcifications were detected, and in 61 patients (45 men; 16 women; mean age: 49.0±11.7 years), coronary calcifications were excluded. ICA excluded CAV in 82 patients (63 men; 19 women; mean age: 48.6±11.9 years). In 79 patients (67 men; 12 women; mean age: 52.5±12.2 years), CAV was detected of whom 11 patients needed stent implantation. No statistically significant difference of DSCTCS in patients without (17.2±29.5; range: 0-190) and with CAV (33.4±66.8; range: 0-385) was observed (P=0.133). Moreover, 4 of 11 (36.4%) severely diseased patients had a calcium score of zero. Sensitivity, specificity, negative predictive value, and positive predictive value for CAV detection (calcium score threshold >0) was calculated as 72.2%, 47.6%, 47.7%, and 57.0%, respectively. Diagnostic accuracy was 59.6%. CONCLUSION: DSCTCS is not a valuable noninvasive modality for CAV detection and thus not recommended in clinical practice. Moreover, we hypothesize that it represents preexisting or de novo traditional coronary atherosclerosis than CAV.

Tissue doppler echocardiography in the diagnosis of heart transplantation rejection.

BACKGROUND: Endomyocardial biopsy (EMB) is the gold standard method for the diagnosis of cellular rejection (CR) after heart transplantation (HT). OBJECTIVE: To test the hypothesis that tissue Doppler imaging (TDI) could detect CR > 3A and add diagnostic information compared to conventional Doppler. METHODS: Fifty-four HT patients underwent 129 EMB and a TDI echocardiographic study within 24 hours. We compared HT patients with CR > 3A versus HT patients with CR < 3A, with a normal matched control group (13 patients). We measured TDI systolic (S), early diastolic (e'), late diastolic (a') velocities and e'/a' ratio in the left ventricular annulus, basal and medium (mid) segments of the septal (SEP), lateral (LAT), inferior (INF), anterior (ANT) walls; and in the right ventricular annulus. RESULTS: HT patients showed CR > 3A in 39/129 (30.2%) EMB. The best isolated predictor for CR diagnosis was a'LAT, with a sensitivity of 76.3%, specificity of 73.8% (p = 0.001). In the multivariate analysis, a'LAT (p = 0.001), a'SEP (p = 0.002), e'/a' LAT ratio (p = 0.006), e'Mitral/ e'LAT ratio (p = 0.014), SINF (p = 0.009) predicted CR > 3A. We obtained a score with a sensitivity of 88.2%, accuracy of 79.6% and negative predictive value of 92.9% to diagnose CR > 3A. Conventional Doppler (mitral and pulmonary venous flow) was not relevant to predict CR > 3A. CONCLUSION: TDI added diagnostic information to predict CR > 3A compared to conventional Doppler. A TDI-based model could become a potential method to detect CR > 3A after heart transplantation.

Allograft morphology and function in heart transplant recipients surviving more than 15 years by magnetic resonance imaging and dual-source computed tomography.

OBJECTIVE: Cardiac allograft vasculopathy and late graft failure are the main limiting factors of long-term success of heart transplantation, and little is known about graft function in the long-term survivors. The aim of this study was to assess the ventricular function and the allograft vasculopathy in long-term survivors (>15 years) with the cardiac magnetic resonance imaging (MRI) and dual-source computed tomography (DSCT) coronary angiogram. METHODS: In our database, 34 cardiac recipients have more than 15 years of follow-up and were evaluated for this study; 22 (65%) of them were enrolled. Mean age at transplant was 46 ± 13.5 years, mean donor age was 28.5 ± 10.1 years, and mean graft ischemic time was 189 ± 58 min. Mean follow-up was 18.5 ± 2.4 years (range 15-22). All patients underwent cardiac MRI and DSCT. RESULTS: Mean left ventricular (LV) volumes indexed to the body surface area (BSA) were within normal range: the end-diastolic volume/BSA was 61 ± 16 ml m(-2), end-systolic volume/BSA was 22 ± 15 ml m(-2), stroke volume/BSA was 38 ± 6 ml m(-2), LV mass/BSA: 72 ± 18 g m(-2), and mean ejection fraction (EF) was 0.59 ± 0.08. Two patients (9%) showed a global cardiac hypokinesia and two other patients (9%) showed akinesia of one segment. At DSCT, 41% of patients had a strictly normal coronary angiogram, 41% had wall thickening and 18% presented a least one >60% stenosis. CONCLUSIONS: Cardiac MRI and DSCT coronary angiogram revealed a normal graft function and morphology after more than 15 years of transplantation. However, a certain number of patients have significant cardiac allograft vasculopathy and another consistent group has initial disease. These patients deserve further follow-up and tailoring of the immunosuppressive regimen.

Systolic prospectively ECG-triggered dual-source CT angiography for evaluation of the coronary arteries in heart transplant recipients.

OBJECTIVES: To assess feasibility, image quality, and radiation dose of prospectively ECG-triggered coronary CT angiography (CTA) in orthotopic heart transplant (OHT) recipients. METHODS: 47 consecutive OHT recipients (40 men, mean age 62.1 ± 10.9 years, mean heart rate 86.3 ± 14.4 bpm) underwent dual-source CTA to rule out coronary allograft vasculopathy in a prospectively ECG-triggered mode with data acquisition during 35% to 45% of the cardiac cycle. Two independent observers blindly assessed image quality on a per-segment and per-vessel basis using a four-point scale (1-excellent, 4-not evaluable). Scores 1-3 were considered acceptable for diagnosis. Multivariate analysis was performed to evaluate differences between image quality scores obtained at different reconstruction intervals. Effective radiation doses were calculated. RESULTS: 671 coronary segments were evaluated. Interobserver agreement on the image quality was κ=0.75. Diagnostic image quality was observed in 93.9%, 95.5% and 93.3% of the segments at 35%, 40% and 45% reconstruction intervals. Mean image quality score was 1.5 ± 0.7 for the entire coronary tree, 1.4 ± 0.7 for the RCA, 1.6 ± 0.8 for the LCA and 1.6 ± 0.7 for the Cx at the best reconstruction interval. Estimated mean radiation dose was 4.5 ± 1.2 mSv. CONCLUSION: Systolic prospectively ECG-triggered CTA allows diagnostic image quality coronary angiograms in OHT recipients at low radiation doses.

Impact of donor-transmitted atherosclerosis on early cardiac allograft vasculopathy: new findings by three-dimensional intravascular ultrasound analysis.

BACKGROUND: The influence of donor-transmitted coronary atherosclerosis (DA) on plaque progression during the first year after cardiac transplantation (Tx) is unknown. METHODS: Serial 3-dimensional intravascular ultrasound (IVUS) studies were performed within 8 weeks (baseline; BL) and at 1 year after Tx in 38 recipients. On the basis of maximum intimal thickness (MIT) at BL, recipients were divided into DA group (DA+; MIT≥0.5 mm, n=23) or non-DA group (DA-; MIT<0.5 mm, n=15). Plaque, lumen, and vessel volume indexes were calculated by volume/measured length (mm/mm) in the left anterior descending artery. Univariate and multivariate regression analyses were attempted to reveal clinical predictors of change in coronary dimensions. RESULTS: During the first year after Tx, plaque volume index increased significantly in DA+ group, but did not change in DA- Group (DA+, 3.0±1.5 to 4.1±1.5 mm/mm, P<0.0001: DA-, 1.2±0.4 to 1.3±0.5 mm/mm, P=0.53). In both groups vessel volume index decreased significantly (DA+, 16.3±3.6 to 14.6±3.3 mm/mm, P=0.003: DA-, 13.5±4.1 to 12.0±3.3 mm/mm, P=0.01), as did lumen volume index (DA+, 13.2±3.1 to 10.5±2.7 mm/mm, P<0.0001: DA-, 12.2±3.7 to 10.7±3.0 mm/mm, P=0.004). Univariate and multivariate regression analyses revealed that DA was one of the strongest predictors for plaque progression. CONCLUSIONS: DA was associated with significant plaque progression during the first year after Tx, and in conjunction with negative remodeling, may be an important determinant of cardiac allograft vasculopathy.