Early commercial experience with a newly designed balloon-expandable transcatheter heart valve: 30-day outcomes and implications of preprocedural computed tomography.

OBJECTIVES: We herein report a single-centre experience with the SAPIEN 3 Ultra balloon-expandable transcatheter aortic valve implantation (TAVI) system. METHODS: Between March 2019 and January 2020, a total of 79 consecutive patients received transfemoral TAVI using the SAPIEN 3 Ultra device. Data were retrospectively analysed according to updated Valve Academic Research Consortium-2 definitions. Detailed analysis of multislice computed tomography data was conducted to identify potential predictors for permanent pacemaker (PPM) implantation and residual paravalvular leakage (PVL) post TAVI. RESULTS: Device success and early safety were 97.5% (77/79) and 94.9% (75/79) with resulting transvalvular peak/mean pressure gradients of 21.1 ± 8.2/10.9 ± 4.4 and PVL >mild in 0/79 patients (0%). Mild PVL was seen in 18.9% (15/79) of cases. Thirty-day mortality was 2.5% (2/79). The Valve Academic Research Consortium-2 adjudicated clinical end points disabling stroke, acute kidney injury and myocardial infarction occurred in 1.3% (1/79), 5.1% (4/79) and 0% (0/79) of patients. Postprocedural PPM implantation was necessary in 7.6% (6/79) of patients. Multislice computed tomography analysis revealed significantly higher calcium amounts of the right coronary cusp in patients in need for postprocedural PPM implantation and a higher eccentricity index in patients with postinterventional mild PVL. CONCLUSIONS: First experience with this newly designed balloon-expandable-transcatheter heart valve demonstrates adequate 30-day outcomes and haemodynamic results with low mortality, low rates of PPM implantation and no residual PVL >mild. The herein-presented multislice computed tomography values with an elevated risk for PPM implantation and residual mild PVL may help to further improve outcomes with this particular transcatheter heart valve in TAVI procedures.

Trends in radiation dose and image quality for pediatric patients with a multidetector CT and a third-generation dual-source dual-energy CT.

AIM: To provide an overview on dose reduction and image quality after the installation of a third-generation dual-source CT (dsCT) in a Pediatric Radiology Department. MATERIALS AND METHODS: We included pediatric patients (< 20 years old) undergoing CT for oncological staging (neck, chest and abdomen) or low-dose chest CT for lung diseases. Each of these two groups were further divided in two age groups (≤ or > 10 years old) including patients scanned in the same period of two consecutive years, in 2017 with a 16-row LightSpeed CT (GE Healthcare) or in 2018 with a Somatom Force dsCT (Siemens Healthineers). Technical parameters such as kVp, mAs, slice thickness, exposure times and dose indicators were retrieved and compared. Image quality was evaluated in consensus by two radiologists on a five-point semiquantitative scale. Nonparametric tests were used. RESULTS: In oncological patients, significantly lower kVp and tube current with better image quality were achieved with the dsCT. Radiation dose (total DLP) was 5-6 times lower with dsCT, thanks also to virtual non-contrast images. In low-dose chest CT, the frequent use of tin filter required higher tube current; a total DLP 3 times lower was achieved with dsCT in patients ≤ 10 years old. The image quality was better with the dsCT in low-dose chest CT protocols. CONCLUSION: The third-generation dsCT provides high-quality images with reduced motion artifacts at lower dose.

Comparison of biomechanical properties in ascending aortic aneurysms of patients with congenital bicuspid aortic valve and Marfan syndrome.

BACKGROUND: In patients with ascending aortic aneurysms (AscAA), biomechanical differences are seen among patients with congenital bicuspid aortic valves (BAV), Marfan syndrome (MFS), and tricuspid aortic valves (TAV). We examined the hemodynamic profiles and ultrastructures of aneurysmal specimens, focusing on vascular remodelling to better understand AscAA pathogenesis. METHODS: A total of 795 patients with BAV (43.97 ±â€¯0.51 years; 93.2% male), 69 with MFS (34.43 ±â€¯1.44 years; 86.2% male), and 90 with TAV (67.27 ±â€¯0.58 years; 60% male) were enrolled, primarily upon admission with AscAA. The biomechanical properties of the aortic root were assessed and intraoperative specimens were analyzed by light-microscopy and two-photon autofluorescence microscopy. RESULTS: Patients with BAV had significantly greater distension of the aortic root, irrespective of age or aneurysmal widening (R2 = 0.543, p < 0.05). This was associated with significantly increase in the size of the tunica media. Patients with MFS displayed significant stiffness in the sinuses that worsened with age (R2 = 0.752, p < 0.001), similar to patients with TAV (R2 = 0.626, p < 0.05). Patients with MFS showed significant root elasticity with aneurysmal growth (R2 = 0.596, p < 0.05) and increased medial degeneration. Patients with TAV maintained biomechanical properties, apart from aneurysmal dimensions and high levels of inflammation. CONCLUSIONS: Among patients with AscAA, those with BAV maintain tissue elasticity in the aortic root, regardless of age. Patients with MFS demonstrate increased sinus stiffness with medial degeneration, both during aging and with aneurysmal growth. Patients with TAV and AscAA present with increased inflammation.

Radiation Dose Optimization in Pediatric Chest CT: Major Indicators of Dose Exposure in 1695 CT Scans over Seven Years.

PURPOSE: To analyze possible influencing factors on radiation exposure in pediatric chest CT using different approaches for radiation dose optimization and to determine major indicators for dose development. MATERIALS AND METHODS: In this retrospective study at a clinic with maximum care facilities including pediatric radiology, 1695 chest CT examinations in 768 patients (median age: 10 years; range: 2 days to 17.9 years) were analyzed. Volume CT dose indices, effective dose, size-specific dose estimate, automatic dose modulation (AEC), and high-pitch protocols (pitch ≥ 3.0) were evaluated by univariate analysis. The image quality of low-dose examinations was compared to higher dose protocols by non-inferiority testing. RESULTS: Median dose-specific values annually decreased by an average of 12 %. High-pitch mode (n = 414) resulted in lower dose parameters (p < 0.001). In unenhanced CT, AEC delivered higher dose values compared to scans with fixed parameters (p < 0.001). In contrast-enhanced CT, the use of AEC yielded a significantly lower radiation dose only in patients older than 16 years (p = 0.04). In the age group 6 to 15 years, the values were higher (p < 0.001). The diagnostic image quality of low-dose scans was non-inferior to high-dose scans (2.18 vs. 2.14). CONCLUSION: Radiation dose of chest CT was reduced without loss of image quality in the last decade. High-pitch scanning was an independent factor in this context. Dose reduction by AEC was limited and only relevant for patients over 16 years. KEY POINTS: · The radiation dose of pediatric chest CT was reduced in the last decade.. · High-pitch scanning is an independent factor of dose optimization.. · Dose reduction by AEC is limited and only relevant for older children.. CITATION FORMAT: · Esser M, Hess S, Teufel M et al. Radiation Dose Optimization in Pediatric Chest CT: Major Indicators of Dose Exposure in 1695 CT Scans over Seven Years. Fortschr Röntgenstr 2018; 190: 1131 - 1140.

Aortic valve anatomy and outcomes after transcatheter aortic valve implantation in bicuspid aortic valves.

PURPOSE: Aortic stenosis (AS) in bicuspid aortic valve (BAV) remains a challenge for transcatheter aortic valve implantation (TAVI). BAV is a condition encountered in young adults as well as elderly patients. Frequently we face in clinical practice elderly patients with BAV and severe AS, but there is little evidence concerning TAVI in this population. The aim of our study was to compare anatomic features and outcomes of bicuspid and tricuspid patients with AS undergoing TAVI. METHODS: 83 consecutive BAV patients undergoing TAVI were matched, in a 1:2 ratio, to 166 tricuspid patients. Multi-detector computed tomography (MDCT) and transthoracic echocardiogram (TTE) were assessed at baseline. Primary endpoint was all-cause mortality and early safety at 30 days according to Valve Academic Research Consortium criteria 2 (VARC-2). Secondary endpoint included device success. RESULTS: BAV patients presented more aortic root calcifications, smaller diameter of left ventricular outflow tract (LVOT) and dilated aorta. We did not observe any statistically significant difference concerning all-cause mortality and early safety at 30 days. However higher intra-procedural TAV-in-TAV bailout procedure was observed in the BAV cohort, with consequent reduction of device success rate. CONCLUSIONS: Patients with BAV present more complex anatomy at baseline as compared to tricuspid AS patients. These anatomical features lead to more frequent TAV-in-TAV bailout procedure and lower device success rate, but are not associated with higher mortality rate at 30 days. Our findings support the feasibility of TAVI in BAV, but larger studies with longer follow-up and a focus on sizing are required.

Imaging of Combat-Related Thoracic Trauma - Review of Penetrating Trauma.

Introduction: Combat-related thoracic trauma is a significant contributor to morbidity and mortality of the casualties from Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF). Penetrating, blunt, and blast injuries were the most common mechanisms of trauma. Imaging plays a key role in the management of combat-related thoracic trauma casualties. This review discusses the imaging manifestations of thoracic injuries from penetrating trauma, emphasizing epidemiology and diagnostic clues seen during OEF and OIF. Materials and Methods: The assessment of radiologic findings in patients who suffer from combat-related thoracic trauma is the basis of this review article. The imaging modalities for this study include multi-detector computed tomography and chest radiography. Results: High-velocity penetrating projectile injuries appear as hemorrhage and re-expansion pulmonary edema from the temporary cavity and a linear, blood-filled track from the permanent cavity. In cases where the projectile passes totally through the body, entrance wounds at the skin surface and tracks through the subcutaneous tissues may be the only indications of penetrating trauma. When assessing vascular injury, special attention should be paid to the right hilum in contrast-enhanced multi-detector computed tomography, as contrast is concentrated in the superior vena cava and superior cavoatrial junction may obscure small fragments. Additionally, CT angiography may show vessel disruption or extravasation of contrast distal to normal vessel location in addition to intraluminal filling defects and pseudo-aneurysms. Tension pneumopericardium may rarely complicate penetrating or blunt chest trauma. On imaging, distension of the pericardial sack by pneumopericardium and compression of the heart support the diagnosis of tension. On multi-detector computed tomography in the acute trauma setting, fluid in the pleural space should be considered hemothorax, particularly when Hounsfield units are above 35. Acutely, extravasated blood will have similar attenuation to the thoracic vasculature, whereas clotted blood will have higher values of 50-90 Hounsfield units. Conclusion: Combat-related thoracic trauma continues to be a significant contributor to the morbidity and mortality of those injured during OEF and OIF. This review of the imaging manifestations of penetrating thoracic injury during OEF and OIF focuses on key diagnostic findings for clinicians caring for combat casualties. The distinct injury pattern and atypical imaging manifestations of penetrating trauma are important to recognize early due to the acuity of this patient population and the influence of accurate diagnosis on clinical management.

Comparison of procedural, clinical and valve performance results of transcatheter aortic valve replacement in patients with bicuspid versus tricuspid aortic stenosis.

BACKGROUND: Limited date describing the procedural, clinical and valve performance results of transcatheter aortic valve replacement (TAVR) in patients with bicuspid versus tricuspid aortic stenosis (TAV). METHODS: Procedural and clinical results were defined and reported according to VARC-2 criteria. RESULTS: Consecutive 87 patients with BAV and 70 patients with TAV were included. Compared to patients with TAV, patients with BAV had similar incidence of second valve implantation (14.9% vs 12.9%, p=0.708), more than mild paravalvular leakage (PVL, 40.2% vs 31.9%, p=0.288), permanent pacemaker implantation (PPM, 24.1% vs 28.6%, p=0.53). Furthermore, the procedural and clinical results of TAVR also did not differ between patients with type 0 and type 1 (second valve implantation: 18.4% vs 11.8%, p=0.71, PVL: 38.8% vs 41.2%, p=0.83, PPM: 18.4% vs 31.6%, p=0.16). The hemodynamic outcomes were similar in patients with BAV and TAV at 1-year (maximum velocity, 2.3 vs 2.2m/s, p=0.307) and 2-year (2.3 vs 2.1m/s, p=0.184) follow-up respectively. Adjusted binary logistic regression analysis found oversizing ratio at 14.45-20.57% is at lower risk for more than mild PVL (OR, 0.069, 95% CI, 0.011-0.428, p=0.004). Moreover, the Kaplan-Meier survival analysis revealed that TAVR in type 0 BAV, type 1 BAV and TAV have comparable risk for midterm mortality (Log rank, p=0.772). CONCLUSION: TAVR in whatever type of BAV appeared to be safe and efficacy, and TAVR in BAV was associated with comparable bioprosthetic function during follow up compared to patients with TAV.

Multi-detector CT: Liver protocol and recent developments.

Multi-detector computed tomography is today the workhorse in the evaluation of the vast majority of patients with known or suspected liver disease. Reasons for that include widespread availability, robustness and repeatability of the technique, time-efficient image acquisitions of large body volumes, high temporal and spatial resolution as well as multiple post-processing capabilities. However, as the technique employs ionizing radiation and intravenous iodine-based contrast media, the associated potential risks have to be taken into account. In this review article, liver protocols in clinical practice are discussed with emphasis on optimisation strategies. Furthermore, recent developments such as perfusion CT and dual-energy CT and their applications are presented.

Effects of low calcium dialysate on the progression of coronary artery calcification in hemodialysis patients: An open-label 12-month randomized clinical trial.

BACKGROUND: The association between the dialysate calcium level and coronary artery calcification (CAC) has not yet been evaluated in hemodialysis patients. The objective of this study was to determine whether lowering the dialysate calcium levels would decrease the progression of coronary artery calcification (CAC) compared to using standard calcium dialysate. METHODS: We conducted an open-label randomized trial with parallel groups. The patients were randomly assigned to either 12-month treatment with low calcium dialysate (LCD; 1.25mmol/L, n=36) or standard calcium dialysate (SCD; 1.5mmol/L, n=40). The primary outcome was the change in the CAC scores assessed by 64-slice multidetector computed tomography after 12months. RESULTS: During the treatment period, CAC scores increased in both groups, especially significant in LCD group (402.5±776.8, 580.5±1011.9, P=0.004). When we defined progressors as patients at second and third tertiles of CAC changes, progressor group had a higher proportion of LCD-treated patients than SCD-treated patients (P=0.0229). In multivariate analysis, LCD treatment is a significant risk factor for increase in CAC scores (odds ratio=5.720, 95% CI: 1.219-26.843, P=0.027). CONCLUSIONS: Use of LCD may accelerate the progression of CAC in patients with chronic hemodialysis over a 12-month period. TRIAL REGISTRATION: Clinical Research Information Service [Internet]; Osong (Chungcheongbuk-do): Korea Centers for Disease Control and Prevention, Ministry of Health and Welfare (Republic of Korea), 2010: KCT0000942. Available from: https://cris.nih.go.kr/cris/search/search_result_st01_kren.jsp?seq=3572&sLeft=2&type=my.

Latest generation of flat detector CT as a peri-interventional diagnostic tool: a comparative study with multidetector CT.

BACKGROUND AND PURPOSE: Flat detector CT (FDCT) has been used as a peri-interventional diagnostic tool in numerous studies with mixed results regarding image quality and detection of intracranial lesions. We compared the diagnostic aspects of the latest generation FDCT with standard multidetector CT (MDCT). MATERIALS AND METHODS: 102 patients were included in our retrospective study. All patients had undergone interventional procedures. FDCT was acquired peri-interventionally and compared with postinterventional MDCT regarding depiction of ventricular/subarachnoidal spaces, detection of intracranial hemorrhage, and delineation of ischemic lesions using an ordinal scale. Ischemic lesions were quantified with the Alberta Stroke Program Early CT Scale (ASPECTS) on both examinations. Two neuroradiologists with varying grades of experience and a medical student scored the anonymized images separately, blinded to the clinical history. RESULTS: The two methods were of equal diagnostic value regarding evaluation of the ventricular system and the subarachnoidal spaces. Subarachnoidal, intraventricular, and parenchymal hemorrhages were detected with a sensitivity of 95%, 97%, and 100% and specificity of 97%, 100%, and 99%, respectively, using FDCT. Gray-white differentiation was feasible in the majority of FDCT scans, and ischemic lesions were detected with a sensitivity of 71% on FDCT, compared with MDCT scans. The mean difference in ASPECTS values on FDCT and MDCT was 0.5 points (95% CI 0.12 to 0.88). CONCLUSIONS: The latest generation of FDCT is a reliable and accurate tool for the detection of intracranial hemorrhage. Gray-white differentiation is feasible in the supratentorial region.

Coronary risk stratification of patients undergoing surgery for valvular heart disease.

BACKGROUND: Multislice computed tomography (MSCT) is a non-invasive, less expensive, low-radiation alternative to coronary angiography (CAG) prior to valvular heart surgery. MSCT has a high negative predictive value for coronary artery disease (CAD) but previous studies of patients with valvular disease have shown that MSCT, as the primary evaluation technique, lead to re-evaluation with CAG in about a third of cases and it is therefore not recommended. If a subgroup of patients with low- to intermediate risk of CAD could be identified and examined with MSCT, it could be cost-effective, reduce radiation and the risk of complications associated with CAG. METHODS: The study cohort was derived from a national registry of patients undergoing CAG prior to valvular heart surgery. Using logistic regression, we identified significant risk factors for CAD and developed a risk score (CT-valve score). The score was validated on a similar cohort of patients from another registry. RESULTS: The study cohort consisted of 2221 patients, 521 (23.5%) had CAD. The validation cohort consisted of 2575 patients, 771 (29.9%) had CAD. The identified risk factors were male sex, age, smoking, hyperlipidemia, hypertension, aortic valve disease, extracardiac arteriopathy, ejection fraction <30% and diabetes mellitus. CT-valve score could identify a third of the population with a risk about 10%. CONCLUSION: A score based on risk factors of CAD can identify patients that might benefit from using MSCT as a gatekeeper to CAG prior to heart valve surgery.

A systematic review and meta-analysis of multidetector computed tomography in the assessment of coronary artery bypass grafts.

PURPOSE: The present meta-analysis aimed to compare the diagnostic accuracy of more recent computed tomography coronary angiography (CTCA) with invasive coronary angiography (ICA) in the assessment of graft patency after coronary artery bypass graft surgery (CABG). MATERIAL AND METHODS: A systematic review was performed using nine electronic databases from their dates of inception to July 2015. Predefined inclusion criteria included studies reporting on comparative outcomes using ≥64 slice multidetector computed tomography (MDCT) and ICA. The primary endpoints included graft occlusion and significant graft stenosis ≥50%. Secondary analyses included the comparison of arterial versus venous graft conduits, and the use of different MDCT techniques. RESULTS: Thirty-one studies were identified according to selection criteria, involving 1975 patients with 5364 assessed grafts. Combined assessment of stenosis and occlusion for all grafts demonstrated a sensitivity of 96.1% [95% confidence interval (CI) 94.3-97.4%] and specificity of 96.3% (95% CI 95.1-97.3%). CTCA assessment of venous grafts demonstrated higher sensitivity compared to arterial grafts, when testing for both occlusion and stenosis (97.6% vs 89.2%, p=0.004). CONCLUSION: Results of this study demonstrated that CTCA had a relatively high pooled sensitivity, specificity and negative predictive value compared to ICA. However, patient baseline characteristics varied between studies, and the results should be interpreted with caution. Nonetheless, our results indicate that CTCA should be recognized as an accurate and non-invasive investigation for graft patency in symptomatic patients after CABG.

Detection and characterization of intracranial aneurysms: a 10-year multidetector CT angiography experience in a large center.

BACKGROUND: CT angiography (CTA) is increasingly used for the detection, characterization, and follow-up of intracranial aneurysms. A lower threshold to request a CT angiogram may render a patient population that differs from previous studies primarily evaluated with conventional angiography. Our objective was to broaden our knowledge of the factors associated with aneurysm rupture and patient mortality in this population. METHODS: All CTA studies performed over a 10-year period at a large neurovascular referral center were reviewed for the presence of an intracranial aneurysm. Patient demographics, mortality, CTA indication, aneurysm location, size, and rupture status were recorded. RESULTS: 2927 patients with aneurysms were identified among 29 003 CTAs. 17% of the aneurysms were ruptured at the time of imaging, 24% of aneurysms were incidentally identified, and multiple aneurysms were identified in 34% of patients. Aneurysms most commonly arose from the supraclinoid internal carotid artery (22%), the middle cerebral artery (18%), and the anterior communicating artery (13%). Male sex, age <50 years, aneurysms >6 mm, and aneurysms arising from the anterior communicating artery, posterior communicating artery, or the posterior circulation were independent predictors of aneurysm rupture. Independent mortality predictors included male sex, posterior circulation aneurysms, intraventricular hemorrhage, and intraparenchymal hemorrhage. CONCLUSIONS: These results indicate that aneurysms detected on CTA that arise from the anterior communicating artery, posterior communicating artery, or the posterior circulation, measure >6 mm in size, occur in men, and in patients aged <50 years are associated with rupture.

[Cross-sectional imaging evaluation of renal masses]. / Schnittbildgebung der Nierentumoren.

Cross-sectional imaging modalities including multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) are the diagnostic standard in detection, characterization, and staging of renal masses due to their high sensitivity and specificity. Currently, most renal masses are incidentally diagnosed by imaging for other medical reasons. Recent developments have improved image acquisition with high resolution, while simultaneously reducing radiation dose. CT imaging is the most accessible cross-sectional imaging method and is, therefore, the standard technique. MRI is indicated in patients who are allergic to intravenous CT contrast medium, in patients with renal insufficiency, or in younger patients. Further characterization of renal masses is possible with functional imaging including dual energy CT, perfusion CT, or diffusion-weighted MRI. Contrast-enhanced ultrasound allows detection of even subtle enhancement in hypovascular lesions with high sensitivity and can add valuable information to CT and MRI studies.

Coronary computed tomography angiography for the assessment of chest pain: current status and future directions.

Chest pain is one of the most common presenting symptoms leading to presentation to medical clinics and Emergency Departments worldwide. Defining the nature and etiology of chest pain can pose a diagnostic dilemma for clinicians, despite the availability of several diagnostic algorithms and guidelines to assist them in evaluating these patients. Most investigations in patients with acute chest pain are initially performed to either exclude or diagnose and manage potentially life-threatening conditions such as acute coronary syndrome, pulmonary embolism and aortic dissection. In cases of stable chest pain syndromes, the focus shifts to determining the presence, extent and severity of coronary artery disease. In recent years, coronary computed tomography angiography (CCTA) is being increasingly used worldwide in the assessment of both stable and acute chest pain syndromes. This review evaluates the current evidence regarding the clinical utility of CCTA in the stable and acute chest pain settings and outlines the latest advances in CCTA techniques, including functional assessment of coronary stenoses, and their potential clinical application to improve patient care in a cost-effective manner.

Left atrial volume is more important than the type of atrial fibrillation in predicting the long-term success of catheter ablation.

BACKGROUND: The type of atrial fibrillation (AF) is the sole prognostic factor that affects the level of recommendation for catheter ablation in the current guidelines. Despite being recognized as a predictor of recurrence, relatively little emphasis is given to left atrium (LA) size. The aim of this study was to assess the relative importance of LA volume and type of AF as predictors of outcome after PVI. METHODS: We assessed 809 consecutive patients with symptomatic drug-refractory AF (584 male, mean age 57 ± 11 years) undergoing 905 percutaneous PVI procedures in two centers. LA volume was assessed by cardiac CT and/or electroanatomical mapping prior to AF ablation. The study endpoint was symptomatic and/or documented AF recurrence. RESULTS: The majority of patients (73.2%, n=592) had paroxysmal AF. The mean indexed LA volume was 55 ± 20 ml/m(2). During a follow-up of 2.4 ± 1.7 years, there were 280 recurrences. The relapse rate of patients with paroxysmal AF in the highest tertile of LA volume was higher than the relapse rate of patients with non-paroxysmal AF in the lowest tertile (20.0% vs. 10.9% per person-year, respectively, p=0.041). LA volume (HR 1.16 for each 10 ml/m(2), 95% CI 1.09-1.23, p<0.001), female gender (HR 1.55, 95% CI 1.19-2.03, p=0.001), and non-paroxysmal AF (HR 1.31, 95% CI 1.01-1.69, p=0.039) were the only independent predictors of AF recurrence. Split-sample cross-validation resampling confirmed LA volume as the strongest predictor of relapse after PVI. CONCLUSION: Left atrial volume seems to be more important than the type of atrial fibrillation in predicting the long-term success of pulmonary vein isolation.

Presence of myocardial hypoenhancement on multidetector computed tomography after primary percutaneous coronary intervention in acute myocardial infarction predicts poor prognosis.

BACKGROUND: Recent research has suggested that patients with greater delayed contrast-enhanced size by multidetector computed tomography (MDCT) are more likely to experience adverse cardiac events and have poor prognoses over the long term. The myocardial hypoenhancement area in the delayed contrast-enhanced effect suggests microvascular obstruction. The outcomes of patients with a hypoenhancement area detected by MDCT have not been clear. We examined the clinical importance of myocardial hypoenhancement detected by delayed contrast-enhanced MDCT after percutaneous coronary intervention (PCI) in patients with acute myocardial infarction. METHODS AND RESULTS: In 80 patients with acute myocardial infarction, MDCT was performed immediately after primary PCI. We investigated the outcomes of the patients with hypoenhancement detected by MDCT. Myocardial hypoenhancement was observed in 14 patients (17.5%). All 14 of these patients with hypoenhancement had a transmural infarction, and their infarct volume was significantly higher than those of the patients without hypoenhancement (n=66). During the median follow-up period of 309 days, the appearance of myocardial hypoenhancement was associated with the presence of slow flow/no-reflow, time from onset to reperfusion ≥6 h, aging, smoking, chronic kidney disease, and hyper-low-density lipoprotein cholesterolemia. The incidence of major adverse cardiovascular events (MACE) was significantly higher in the patients with hypoenhancement compared to those without hypoenhancement, regardless of the myocardial infarct volume. CONCLUSIONS: These results indicate that the presence of myocardial hypoenhancement in delayed contrast-enhanced MDCT after PCI as well as the extent of infarct area is an important predictor of MACE.