Proximal aortic stiffening in Turner patients may be present before dilation can be detected: a segmental functional MRI study.

BACKGROUND: To study segmental structural and functional aortic properties in Turner syndrome (TS) patients. Aortic abnormalities contribute to increased morbidity and mortality of women with Turner syndrome. Cardiovascular magnetic resonance (CMR) allows segmental study of aortic elastic properties. METHOD: We performed Pulse Wave Velocity (PWV) and distensibility measurements using CMR of the thoracic and abdominal aorta in 55 TS-patients, aged 13-59y, and in a control population (n = 38;12-58y). We investigated the contribution of TS on aortic stiffness in our entire cohort, in bicuspid (BAV) versus tricuspid (TAV) aortic valve-morphology subgroups, and in the younger and older subgroups. RESULTS: Differences in aortic properties were only seen at the most proximal aortic level. BAV Turner patients had significantly higher PWV, compared to TAV Turner (p = 0.014), who in turn had significantly higher PWV compared to controls (p = 0.010). BAV Turner patients had significantly larger ascending aortic (AA) luminal area and lower AA distensibility compared to both controls (all p < 0.01) and TAV Turner patients. TAV Turner had similar AA luminal areas and AA distensibility compared to Controls. Functional changes are present in younger and older Turner subjects, whereas ascending aortic dilation is prominent in older Turner patients. Clinically relevant dilatation (TAV and BAV) was associated with reduced distensibility. CONCLUSION: Aortic stiffening and dilation in TS affects the proximal aorta, and is more pronounced, although not exclusively, in BAV TS patients. Functional abnormalities are present at an early age, suggesting an aortic wall disease inherent to the TS. Whether this increased stiffness at young age can predict later dilatation needs to be studied longitudinally.

The spectrum of spontaneous coronary artery dissection: illustrated review of the literature.

Spontaneous coronary artery dissection or SCAD is a rare and challenging disease that is increasingly diagnosed. It is characterized by a non-traumatic, non-iatrogenic separation of the coronary artery wall and occurs predominantly in young and middle-aged women without traditional cardiovascular risk factors. SCAD is often associated with predisposing conditions such as the peripartum period, systemic inflammatory disease and heritable connective tissue disease. More recently, independent investigators have demonstrated an important association with fibromuscular dysplasia. Extreme emotional or physical stress as well as intense hormonal therapy or drug abuse have been pointed out as precipitating factors. The diagnosis of SCAD can be challenging and starts with clinical suspicion. Advanced imaging techniques such as intravascular ultrasound and optical coherence tomography are useful for the differentiation from atherosclerotic disease and are increasingly used for this indication. The proposed treatment in the acute setting is based on findings from single-centre retrospective series: in stable patients with a TIMI-flow ≥2 a conservative management is proposed because of the high risk of procedural failure and complications as well as a high probability of spontaneous healing. Long-term treatment is comparable to that in non-SCAD acute coronary syndromes (ACS) but dual antiplatelet therapy should only be started in case of stenting and should be kept as short as possible in patients with vascular Ehlers-Danlos syndrome. Prognosis seems to be better compared to non-SCAD ACS but there is a reasonable risk of recurrence. In this review, we discuss the current knowledge of SCAD and provide a clinical pathway for the diagnosis, management and work-up of SCAD patients.

Efficacy of losartan as add-on therapy to prevent aortic growth and ventricular dysfunction in patients with Marfan syndrome: a randomized, double-blind clinical trial.

BACKGROUND: Marfan syndrome (MFS) is a multisystemic hereditary connective tissue disease. Aortic root aneurysms and dissections are the most common and life-threatening cardiovascular disorders affecting these patients. Other cardiac manifestations include mitral valve prolapse, ventricular dysfunction and arrhythmias. Medical treatment of cardiovascular features is ultimately aimed at slowing down aortic root growth rate and preventing dissection. Losartan has been proposed as a new therapeutic tool for this purpose. To which extent losartan affects cardiac function has not been studied previously. METHODS: We designed a prospective, double-blind, randomized placebo-controlled trial to evaluate the effect of losartan added to beta-blocker therapy on aortic growth and ventricular function in patients with MFS. Secondary outcomes were aortic dissection, prophylactic aortic surgery and death. RESULTS: Twenty-two patients were enrolled in the trial. There was a mild and similar increase in the aortic root during the 3 years of follow-up in both groups (median 1 mm, IQR [-1-1.5] and 1 mm, IQR [-0.25-1] in the losartan and placebo group, respectively, p = 1). Diastolic and systolic ventricular function was normal at baseline in both groups and remained stable during the study. One patient in the placebo group presented a subclavian artery dissection during follow-up. CONCLUSION: Losartan on top of beta-blocker therapy has no additional effect on aortic growth or on cardiac function in patients with MFS. Our results are underpowered but are in line with the result from other groups. In order to have a better insight on whether a group of patients could benefit more from losartan therapy, the outcome of an on-going meta-analysis should be awaited.

MR pulse wave velocity increases with age faster in the thoracic aorta than in the abdominal aorta.

PURPOSE: To assess the difference between thoracic and abdominal aortic pulse wave velocity (PWV) in apparently healthy subjects including young adults to elderly subjects. MATERIALS AND METHODS: We performed PWV and distensibility measurements and analysis of thoracic and abdominal aortic segments in 96 apparently normal subjects aged 20-80 years with magnetic resonance (MR). Both unadjusted correlation and General Linear Model (GLM) analysis of log-transformed PWV (thoracic and abdominal aorta) and distensibility (four aortic cross-sections) were performed. RESULTS: Both thoracic and abdominal PWV values and distensibility values increased with age. In unadjusted analyses the correlation between the ln(thoracic PWV) and age (r = 0.71; P < 0.001) was stronger than between ln(abdominal PWV) and age (r = 0.50; P < 0.001). In GLM analysis, the only determinant of thoracic and abdominal PWV was age (F = 42.5 and F = 14.8, respectively; both P < 0.001). Similarly, correlation between ln(distensibility) and age was strong (r = -0.79, r = -0.67, r = -0.71, and r = -0.65 for ascending, descending, diaphragmatic, and low abdominal aorta, respectively; all P < 0.001). In GLM analysis, age was the major determinant for distensibility of the ascending aorta (F = 81.7; P < 0.001), descending aorta (F = 42.2; P < 0.001), diaphragmatic aorta (F = 39.2; P < 0.001), and low abdominal aorta (F = 32.8; P < 0.001). CONCLUSION: The thoracic aorta is less stiff than the abdominal aorta in young and middle-aged subjects, and stiffens more rapidly with age than the abdominal aorta, resulting in a stiffer thoracic than abdominal aorta at older age.

Organ Doses and Radiation Risk of Computed Tomographic Coronary Angiography in a Clinical Patient Population: How Do Low-Dose Acquisition Modes Compare?

OBJECTIVE: To compare the organ doses and lifetime-attributable risk of cancer for electrocardiogram-triggered sequential and high-pitch helical scanning in a clinical patient population. METHODS: Phantom thermoluminiscence dosimeter measurements were used as a model for the organ dose assessment of 314 individual patients who underwent coronary computed tomographic angiography. Patient-specific lifetime-attributable cancer risks were calculated. RESULTS: Phantom measurements showed that heart rate had a significant influence on the delivered radiation exposure in sequential mode, and calcium scoring and contrast bolus tracking scans make a nonnegligible contribution to patients' dose. Therefore, they should be taken into account for patients' organ dose estimations. Median cancer induction risks are low, with 0.008% (0.0016%) and 0.022% (0.056%) for high-pitch and sequential scanning for men (women), respectively. CONCLUSIONS: The use of high-pitch helical scanning leads to 65% and 72% lower lifetime-attributable risk values for men and women, respectively, compared with sequential scanning.

Abnormal aortic arch morphology in Turner syndrome patients is a risk factor for hypertension.

Hypertension in Turner syndrome (TS) is a multifactorial, highly prevalent and significant problem that warrants timely diagnosis and rigorous treatment. The objective of this study was to investigate the association between abnormal aortic arch morphology and hypertension in adult TS patients. This was a single centre retrospective study in 74 adult TS patients (age 29.41 ± 8.91 years) who underwent a routine cardiac MRI. Patients were assigned to the hypertensive group (N = 31) if blood pressure exceeded 140/90 mmHg and/or if they were treated with antihypertensive medication. Aortic arch morphology was evaluated on MRI images and initially assigned as normal (N = 54) or abnormal (N = 20), based on the curve of the transverse arch and the distance between the left common carotid-left subclavian artery. We additionally used a new more objective method to describe aortic arch abnormality in TS by determination of the relative position of the highest point of the transverse arch (AoHP). Logistic regression analysis showed that hypertension is significantly and independently associated with age, BMI and abnormal arch morphology, with a larger effect size for the new AoHP method than for the classical method. TS patients with hypertension and abnormal arch morphology more often had dilatation of the ascending aorta. There is a significant association between abnormal arch morphology and hypertension in TS patients, independent of age and BMI, and not related to other structural heart disease. We suggest that aortic arch morphology should be included in the risk stratification for hypertension in TS and propose a new quantitative method to express aortic arch morphology.

SurLym trial: study protocol for a multicentre pragmatic randomised controlled trial on the added value of reconstructive lymphatic surgery to decongestive lymphatic therapy for the treatment of lymphoedema.

INTRODUCTION: Lymphoedema is a chronic condition caused by lymphatic insufficiency. It leads to swelling of the limb/midline region and an increased risk of infection. Lymphoedema is often associated with mental and physical problems limiting quality of life. The first choice of treatment is a conservative treatment, consisting of exercises, skin care, lymph drainage and compression. Reconstructive lymphatic surgery is also often performed, that is, lymphovenous anastomoses, lymph node transfer or a combination. However, robust evidence on the effectiveness of reconstructive lymphatic surgery is missing. Therefore, the objective of this trial is to investigate the added value of reconstructive lymphatic surgery to the conservative treatment in patients with lymphoedema. METHODS AND ANALYSIS: A multicentre randomised controlled and pragmatic trial was started in March 2022 in three Belgian university hospitals. 90 patients with arm lymphoedema and 90 patients with leg lymphoedema will be included. All patients are randomised between conservative treatment alone (control group) or conservative treatment with reconstructive lymphatic surgery (intervention group). Assessments are performed at baseline and at 1, 3, 6, 12, 18, 24 and 36 months. The primary outcome is lymphoedema-specific quality of life at 18 months. Key secondary outcomes are limb volume and duration of wearing the compression garment at 18 months. The approach of reconstructive lymphatic surgery is based on presurgical investigations including clinical examination, lymphofluoroscopy, lymphoscintigraphy, lymph MRI or CT angiography (if needed). All patients receive conservative treatment during 36 months, which is applied by the patient's own physical therapist and by the patient self. From months 7 to 12, the hours a day of wearing the compression garment are gradually decreased. ETHICS AND DISSEMINATION: The study has been approved by the ethical committees of University Hospitals Leuven, Ghent University Hospital and CHU UCL Namur. Results will be disseminated via peer-reviewed journals and presentations. TRIAL REGISTRATION NUMBER: NCT05064176.

Safety of meglumine gadoterate (Gd-DOTA)-enhanced MRI compared to unenhanced MRI in patients with chronic kidney disease (RESCUE study).

OBJECTIVE: To prospectively compare the renal safety of meglumine gadoterate (Gd-DOTA)-enhanced magnetic resonance imaging (MRI) to a control group (unenhanced MRI) in high-risk patients. METHODS: Patients with chronic kidney disease (CKD) scheduled for MRI procedures were screened. The primary endpoint was the percentage of patients with an elevation of serum creatinine levels, measured 72 ± 24 h after the MRI procedure, by at least 25 % or 44.2 µmol/l (0.5 mg/dl) from baseline. A non-inferiority margin of the between-group difference was set at -15 % for statistical analysis of the primary endpoint. Main secondary endpoints were the variation in serum creatinine and eGFR values between baseline and 72 ± 24 h after MRI and the percentage of patients with a decrease in eGFR of at least 25 % from baseline. Patients were screened for signs of nephrogenic systemic fibrosis (NSF) at 3-month follow-up. RESULTS: Among the 114 evaluable patients, one (1.4 %) in the Gd-DOTA-MRI group and none in the control group met the criteria of the primary endpoint [Δ = -1.4 %, 95%CI = (-7.9 %; 6.7 %)]. Non-inferiority was therefore demonstrated (P = 0.001). No clinically significant differences were observed between groups for the secondary endpoints. No serious safety events (including NSF) were noted. CONCLUSION: Meglumine gadoterate did not affect renal function and was a safe contrast agent in patients with CKD. KEY POINTS: • Contrast-induced nephropathy (CIN) is a potential problem following gadolinium administration for MRI. • Meglumine gadoterate (Gd-DOTA) appears safe, even in patients with chronic kidney disease. • Gd-DOTA only caused a temporary creatinine level increase in 1/70 such patients. • No case or sign of NSF was detected at 3-month follow-up.

The Hammock Sign in Computed Tomography as a Detection Aid for Bicuspid Aortic Valves.

Introduction: Bicuspid aortic valve is difficult to detect on standard transverse images. Purpose: We aimed to investigate the usefulness of the hammock sign for detection of bicuspid aortic valve. Methods: We retrospectively investigated the usefulness of a newly proposed 'hammock sign' in a population of 45 contrast enhanced computer tomographic studies to discern tricuspid (22) from anatomical bicuspid aortic (23) valves. The gold standard of aortic morphology was the definite diagnosis in the patient's medical file, established by computed tomography, magnetic resonance, or surgery. Results: Computer tomographic (CT) studies of each aortic morphology were randomly evaluated for the presence of the hammock sign on coronal and sagittal images, by two readers blinded to the diagnosis. Sensitivity for detecting an anatomic bicuspid valve was 86%, and specificity was 100%. Conclusion: The hammock sign allows for a quick and easy diagnosis of an anatomical bicuspid aortic valve, merely by scrolling through the standard coronal reconstructions of any type of contrast-enhanced thoracic CT study, and regardless of any other findings associated with bicuspid aortic valve. Functional bicuspid aortic valves were not the scope of this study.

Serum Calcification Propensity T50 Associates with Disease Severity in Patients with Pseudoxanthoma Elasticum.

Pseudoxanthoma elasticum (PXE) is a currently intractable genetic disorder characterized by progressive ectopic calcification in the skin, eyes and arteries. Therapeutic trials in PXE are severely hampered by the lack of reliable biomarkers. Serum calcification propensity T50 is a blood test measuring the functional anticalcifying buffer capacity of serum. Here, we evaluated T50 in PXE patients aiming to investigate its determinants and suitability as a potential biomarker for disease severity. Fifty-seven PXE patients were included in this cross-sectional study, and demographic, clinical, imaging and biochemical data were collected from medical health records. PXE severity was assessed using Phenodex scores. T50 was measured using a validated, nephelometry-based assay. Multivariate models were then created to investigate T50 determinants and associations with disease severity. In short, the mean age of patients was 45.2 years, 68.4% was female and mean serum T50 was 347 min. Multivariate regression analysis identified serum fetuin-A (p < 0.001), phosphorus (p = 0.007) and magnesium levels (p = 0.034) as significant determinants of T50, while no correlations were identified with serum calcium, eGFR, plasma PPi levels or the ABCC6 genotype. After correction for covariates, T50 was found to be an independent determinant of ocular (p = 0.013), vascular (p = 0.013) and overall disease severity (p = 0.016) in PXE. To conclude, shorter serum T50­indicative of a higher calcification propensity­was associated with a more severe phenotype in PXE patients. This study indicates, for the first time, that serum T50 might be a clinically relevant biomarker in PXE and may thus be of importance to future therapeutic trials.

A case report: cardiac dysphagia-a ghost of the past?

BACKGROUND: Rheumatic heart disease has become rare in developed countries and physicians have grown unfamiliar with the disease and its clinical course. The mitral valve is most commonly affected leading to mitral regurgitation and/or stenosis. The chronic volume and/or pressure overload leads to atrial remodelling and enlargement, driving the development of atrial fibrillation and thrombo-embolic events. CASE SUMMARY: A 87-year-old patient with a history of rheumatic mitral stenosis and mitral valve replacement was admitted to the neurology department for vertigo. A stroke was suspected, and she underwent a transoesophageal echocardiogram (TOE) which was complicated by dysphagia. Oesophageal manometry and computed tomography revealed oesophagogastric junction outflow obstruction due to extrinsic compression by a giant left atrium (GLA). DISCUSSION: Dysphagia due to a GLA is rare. Various diagnostic criteria exist and the prevalence thus depends on which criterium is used. It is mostly encountered in rheumatic mitral disease, although there are reports of non-rheumatic aetiology. When the left atrium assumes giant proportions it can compress adjacent intrathoracic structures. Compression of the oesophagus can lead to dysphagia, as in our case. A TOE in these cases is relatively contraindicated and should only be performed if there is considerable reason to believe that it may change patient management.

Validation of the murine aortic arch as a model to study human vascular diseases.

Although the murine thoracic aorta and its main branches are widely studied to gain more insight into the pathogenesis of human vascular diseases, detailed anatomical data on the murine aorta are sparse. Moreover, comparative studies between mice and men focusing on the topography and geometry of the heart and aorta are lacking. As this hampers the validation of murine vascular models, the branching pattern of the murine thoracic aorta was examined in 30 vascular corrosion casts. On six casts the intrathoracic position of the heart was compared with that of six younger and six older men of whom contrast-enhanced computer tomography images of the thorax were three-dimensionally reconstructed. In addition, the geometry of the human thoracic aorta was compared with that of the mouse by reconstructing micro-computer tomography images of six murine casts. It was found that the right brachiocephalic trunk, left common carotid artery and left subclavian artery branched subsequently from the aortic arch in both mice and men. The geometry of the branches of the murine aortic arch was quite similar to that of men. In both species the initial segment of the aorta, comprising the ascending aorta, aortic arch and cranial/superior part of the descending aorta, was sigmoidally curved on a cranial/superior view. Although some analogy between the intrathoracic position of the murine and human heart was observed, the murine heart manifestly deviated more ventrally. The major conclusion of this study is that, in both mice and men, the ascending and descending aorta do not lie in a single vertical plane (non-planar aortic geometry). This contrasts clearly with most domestic mammals in which a planar aortic pattern is present. As the vascular branching pattern of the aortic arch is also similar in mice and men, the murine model seems valuable to study human vascular diseases.

Calculations of cardiovascular shunts and regurgitation using magnetic resonance ventricular volume and aortic and pulmonary flow measurements.

BACKGROUND: Cardiovascular magnetic resonance measurements of the volumes of the right and left ventricle and of the flows in the ascending aorta and main pulmonary artery contribute to the assessment of patients with valvular regurgitation or intracardiac or extracardiac shunts. Ventricular volumes are measured by planimetry and summation of end-diastolic and end-systolic areas measured in a stack of ventricular short-axis cines. The volumes of blood flowing through planes transecting the great arteries are measured using phase contrast velocity mapping. The two approaches are essentially different and can be used either for mutual validation, or separately or in combination to quantify regurgitation and/or shunting. In the presence of shunts, the relations between the stroke volumes and arterial flows of each side of the heart vary depending on the level of shunting (for example, atrial, ventricular or ductal). CONCLUSION: This article aims to explain and illustrate the technical and theoretical basis for calculations using volumetric and flow measurements, providing formulae and diagrams to facilitate the interpretation of results.

Myocardial disease and ventricular arrhythmia in Marfan syndrome: a prospective study.

BACKGROUND: Aortic root dilatation and-dissection and mitral valve prolapse are established cardiovascular manifestations in Marfan syndrome (MFS). Heart failure and arrhythmic sudden cardiac death have emerged as additional causes of morbidity and mortality. METHODS: To characterize myocardial dysfunction and arrhythmia in MFS we conducted a prospective longitudinal case-control study including 86 patients with MFS (55.8% women, mean age 36.3 yr-range 13-70 yr-) and 40 age-and sex-matched healthy controls. Cardiac ultrasound, resting and ambulatory ECG (AECG) and NT-proBNP measurements were performed in all subjects at baseline. Additionally, patients with MFS underwent 2 extra evaluations during 30 ± 7 months follow-up. To study primary versus secondary myocardial involvement, patients with MFS were divided in 2 groups: without previous surgery and normal/mild valvular function (MFS-1; N = 55) and with previous surgery or valvular dysfunction (MFS-2; N = 31). RESULTS: Compared to controls, patients in MFS-1 showed mild myocardial disease reflected in a larger left ventricular end-diastolic diameter (LVEDD), lower TAPSE and higher amount of (supra) ventricular extrasystoles [(S)VES]. Patients in MFS-2 were more severely affected. Seven patients (five in MFS-2) presented decreased LV ejection fraction. Twenty patients (twelve in MFS-2) had non-sustained ventricular tachycardia (NSVT) in at least one AECG. Larger LVEDD and higher amount of VES were independently associated with NSVT. CONCLUSION: Our study shows mild but significant myocardial involvement in patients with MFS. Patients with previous surgery or valvular dysfunction are more severely affected. Evaluation of myocardial function with echocardiography and AECG should be considered in all patients with MFS, especially in those with valvular disease and a history of cardiac surgery.

Abnormal Aortic Wall Properties in Women with Turner Syndrome.

BACKGROUND: Turner syndrome (TS) is associated with aortic dilatation and dissection, but the underlying process is unclear. The aim of this study was to investigate the elastic properties and composition of the aortic wall in women with TS. METHODS: In this cross-sectional study, 52 women with TS aged 35 ± 13 years (50% monosomy, 12 with bicuspid aortic valve [BAV] and 4 with coarctation) were investigated using carotid-femoral pulse wave velocity (CF-PWV) by echocardiography and ascending aortic distensibility (AAD) and aortic arch pulse wave velocity (AA-PWV) by magnetic resonance imaging (MRI). As control group, 13 women with BAV without TS and 48 healthy patients were included. RESULTS: Women with TS showed a higher AA-PWV (ß = 1.08, confidence interval [CI]: 0.54-1.62) after correcting for age and comorbidities compared with controls. We found no significant difference in AAD and CF-PWV. In women with TS, the presence of BAV, coarctation of the aorta, or monosomy (45, X) was not associated with aortic stiffness. In addition, aortic tissue samples were investigated with routine and immunohistochemical stains in five additional women with TS who were operated. The tissue showed more compact smooth muscle cell layers with abnormal deposition and structure of elastin and diminished or absent expression of contractile proteins desmin, actin, and caldesmon, as well as the progesterone receptor. CONCLUSION: Both aortic arch stiffness measurements on MRI and histomorphological changes point toward an inherent abnormal thoracic aortic wall in women with TS.

Left atrial appendage segmentation from 3D CCTA images for occluder placement procedure.

BACKGROUND: Percutaneous left atrial appendage (LAA) closure (placement of an occluder to close the appendage) is a novel procedure for stroke prevention in patients suffering from atrial fibrillation. The closure procedure planning requires accurate LAA measurements which can be obtained from computed tomography (CT) images. METHOD: We propose a novel semi-automatic LAA segmentation method from 3D coronary CT angiography (CCTA) images. The method segments the LAA, proposes the location for the occluder placement (a delineation plane between the left atrium and LAA) and calculates measurements needed for closure procedure planning. The method requires only two inputs from the user: a threshold value and a single seed point inside the LAA. Proposed location of the delineation plane can be intuitively corrected if necessary. Measurements are calculated from the segmented LAA according to the final delineation plane. RESULTS: Performance of the proposed method is validated on 17 CCTA images, manually segmented by two medical doctors. We achieve the average dice coefficient overlap of 92.52% and 91.63% against the ground truth segmentations. The average dice coefficient overlap between the two ground truth segmentations is 92.66%. Our proposed LAA orifice localization is evaluated against the desired location of the LAA orifice determined by the expert. The average distance between our proposed location and the desired location is 2.51 mm. CONCLUSION: Segmentation results show high correspondence to the ground truth segmentations. The occluder placement method shows high accuracy which indicates potential in clinical procedure planning.

An unexpected cause of liver cirrhosis and cardiomyopathy in a young man.

Introduction Juvenile hemochromatosis is a rare but severe form of hereditary hemochromatosis that typically presents early in life and can be fatal if left untreated. Case presentation We present the case of a 30-year-old man with a clear symptomatology of juvenile hemochromatosis, but in whom the diagnosis was initially mistaken for alcoholic liver disease because of known excessive use of alcohol, with the consequence that an adequate treatment was postponed. Discussion In this report, we discuss the diagnosis and treatment of juvenile hemochromatosis, focusing on the interaction between hemochromatosis and alcohol induced liver disease and how to differentiate both. We conclude that every young patient with suspected alcoholic liver disease and signs of iron overload should have a testing to rule out other iron overloading pathology, since early recognition and treatment with phlebotomy may prevent organ damage and improve life expectancy.

Grading of mitral regurgitation based on intensity analysis of the continuous wave Doppler signal.

OBJECTIVES: Echocardiographic methods are used to quantify mitral regurgitation (MR) severity; however, their applicability, accuracy and reproducibility have been debated. We aimed to develop and validate a novel custom-made transthoracic echocardiographic method for grading MR severity based on average pixel intensity (API) analysis of the continuous wave (CW) Doppler envelope. METHODS: MR was assessed in 290 patients using API, colour Doppler imaging, vena contracta width (VCW) and proximal iso-velocity surface area (PISA) method. For the validation of the API method, a pulsatile in vitro cardiac phantom was used. RESULTS: Indices of MR severity, such as left ventricular and atrial dimension, pulmonary arterial pressure, significantly cosegregate with API severity (p≤0.002). The API method showed a linear correlation with colour Doppler (r=0.79), VCW (r=0.68), PISA-effective regurgitant orifice area (r=0.72) and PISA-regurgitant volume (r=0.67); p<0.001 for all. The API was significantly more applicable than VCW (95% vs 75% of all patients; p<0.001) and PISA-based methods (65%; p<0.001). Additionally, the API showed a stronger intraobserver and interobserver agreement compared with other methods. Finally, in the in vitro validation, API values showed a strong linear correlation with increasing regurgitant volumes (r=0.81; p<0.001). CONCLUSIONS: We showed the clinical feasibility and in vitro validation of a novel digital quantitative echocardiographic method to grade MR severity. This method is more applicable and has less interobserver and intraobserver variability compared with current quantitative methods.