The Role of New Imaging Technologies in the Diagnosis of Cardiac Amyloidosis.

Cardiac amyloidosis is an infiltrative disorder caused by transthyretin or immunoglobulin free light-chain deposition, which determines clinical disease with similar phenotype but different time course, prognosis and therapy. Multimodality imaging is the cornerstone for disease diagnosis and management. Multimodality imaging has revolutionized the approach to the disease favoring its awareness and simplifying its diagnosis, especially in ATTR cardiac amyloidosis. This describes the different imaging tools, from the traditional to the more novel ones, and highlights the different approach in each different setting (prognosis, subtyping, prognosis, monitoring disease progression, and response to therapy).

Diagnosis and Management of Left Atrium Appendage Thrombosis in Atrial Fibrillation Patients Undergoing Cardioversion.

Atrial fibrillation is the most common cardiac arrhythmia and is associated with an increased risk of stroke and thromboembolic complications. A rhythm control strategy with both electrical and pharmacological cardioversion is recommended for patients with symptomatic atrial fibrillation. Anticoagulant therapy for 3-4 weeks prior to cardioversion is recommended in order to avoid thromboembolic events deriving from restoring sinus rhythm. Transesophageal echocardiography has a pivotal role in this setting, excluding the presence of left atrial appendage thrombus before cardioversion. The aim of this review is to discuss the epidemiology and risk factors for left atrial appendage thrombosis, the role of echocardiography in the decision making before cardioversion, and the efficacy of different anticoagulant regimens on the detection and treatment of left atrial appendage thrombosis.

The mitral-to-aortic flow-velocity integral ratio in the real world echocardiographic evaluation of functional mitral regurgitation before and after percutaneous repair.

INTRODUCTION: Percutaneous mitral valve repair (PMVR) using MitraClip system has emerged as a therapeutic option for patients with functional severe mitral regurgitation (FMR) at prohibitive risk for surgery. In this setting, the echocardiographic assessment of FMR severity is challenging because the traditional echocardiographic methods have important limitations. The aim of this study was to assess the accuracy and reliability of a simple Doppler index, the mitral/aortic flow velocity integral ratio (MAVIR), to evaluate residual FMR severity after PMVR. METHODS: Eighty-five heart failure patients with functional MR and LV dysfunction (LVEF ≤ 40%) were included. FMR was quantified on the basis of traditional quantitative parameters of MR severity. MAVIR was expressed as the ratio of mitral and aortic time velocity integral (TVI) values. According to MR severity, 25 patients underwent MC implantation and at 6 months a complete echocardiographic follow-up was performed. RESULTS: A significant linear relationship was found between MAVIR and both VC and EROA. A MAVIR ≥1.02 identified pts with severe MR with a sensitivity of 86.7% and a specificity of 90.9%. At the 6 months echocardiographic follow-up after the MitraClip implantation, we observed a significant reduction of LAVI, LVED and LVES volume, while LVEF improved. Furthermore, MAVIR significantly decreased its decrease showed a significant linear relationship with LAVI reduction. CONCLUSION: Our data show a close relationship between MAVIR and traditional indexes of MR severity in patients with FMR. This Doppler-derived index seems applicable after PMVR where traditional echocardiographic index of MR severity shows significant limitations.

Prevalence and clinical significance of right ventricular pulmonary arterial uncoupling in cardiac amyloidosis.

BACKGROUND: This study aims to evaluate the prevalence and the clinical significance of the right ventricular pulmonary arterial (RV-PA) uncoupling in patients with cardiac amyloidosis (CA). METHODS: The study population consisted in 92 consecutive patients with CA (age 71.1 ± 12.2 years, 71% males; 47% with immunoglobulin light chain (AL), 53% with transthyretin [ATTR]). A pre-specified tricuspid anulus plane systolic excursion on pulmonary arterial systolic pressure (TAPSE/PASP) value <0.31 mm/mmHg was used to define RV-PA uncoupling and to dichotomize the study population. RESULTS: Thirty-two patients (35%) showed RV-PA uncoupling at baseline evaluation (15/44 [34%] AL and 17/48 [35%] ATTR). Patients with RV-PA uncoupling, in both AL and ATTR, showed worse NYHA functional class, lower systemic blood pressure, and more pronounced left ventricular and RV systolic dysfunction than those with RV-PA coupling. During a median follow-up of 8 months (IQR 4-13), 26 patients (28%) experienced cardiovascular death. Patients with RV-PA uncoupling showed lower survival at 12 months follow-up than those with RV-PA coupling (42.7% [95%CI 21.7-63.7%] vs. 87.3% [95%CI 78.3-96.3%], p-value<0.001). Multivariate analysis identified high-sensitivity troponin I values (HR 1.01 [95%CI 1.00-1.02] per 1 pg/mL increase; p-value 0.013) and TAPSE/PASP (HR 1.07 [95%CI 1.03-1.11] per 0.01 mm/mmHg decrease; p-value 0.002) as independent predictors of cardiovascular death. CONCLUSIONS: RV-PA uncoupling is common among patient with CA, and it is a marker of advanced disease and worse outcome. This study suggest that TAPSE/PASP ratio has the potential to improve risk stratification and guide management strategies in patients with CA of different etiology and advanced disease.

Global Left Ventricular Myocardial Work Efficiency in Heart Failure Patients with Cardiac Amyloidosis: Pathophysiological Implications and Role in Differential Diagnosis.

INTRODUCTION: Cardiac amyloidosis (CA) is an infiltrative cardiomyopathy and a common cause of heart failure with preserved and mid-range ejection fraction (HFpEF and HFmrEF). Left ventricular (LV) systolic assessment is pivotal in differential diagnostic and prognostic stratification in CA. However, nondeformation and deformation-based parameters classically implied had many limitations. Myocardial work (MW) has been recently introduced for the evaluation of myocardial performance, in a load-independent fashion, in patients with cardiomyopathies. AIMS: This study aimed to evaluate MW parameters in LV performance assessment in CA and their possible role in differential diagnosis between AL and ATTR forms, compared with other echocardiographic parameters, also exploring the possible association between MW parameters and blood biomarkers. MATERIALS AND METHODS: The study population consisted of 25 patients with CA (10 with AL amyloidosis and 15 with wild-type ATTR [ATTRwt] form) and HFpEF or HFmrHF, enrolled between March 2018 and December 2019, undergoing a comprehensive clinical, biochemical, and imaging evaluation. Ten healthy individuals were studied as controls. ATTR patients had a noninvasive diagnosis of wtATTR-CA (positive 99mTc-hydroxy methylene-diphosphonate scintigraphy with a negative hematological screening), while AL patients underwent endomyocardial biopsy. All patients underwent standard transthoracic echocardiography. MW and related indices were estimated using a vendor-specific module. RESULTS: Compared to the ATTRwt group, patients in the AL group showed a more pronounced myocardial performance impairment assessed by Global Word Efficiency (GWE: 83.5% ± 6.3% vs. 88.2% ± 3.6%; P = 0.026). In multiple linear regression analysis, cardiac troponin I (Β = -0.55; P < 0.0001), global longitudinal strain (Β =0.35; P < 0.008), and regional relative strain ratio (Β = -0.30; P < 0.016) were significant predictors of GWE reduction in CA patients. At receiver operating characteristics curve analysis, among all other deformation-based and nondeformation-based echocardiographic parameters, GWE showed the highest area under the curve (AUC) (AUC 0.74; 95% CI: 0.55-0.96; P < 0.04). The optimal cutoff was determined by sensitivity/specificity analysis: a GWE < 86.5% identified patients with AL amyloidosis with a sensitivity and specificity, respectively, of 80.0% and 66.7%. CONCLUSIONS: The results of our pivotal study seem to highlight the importance of new deformation parameters to study myocardial performance in patients with CA, and to differentiate between AL CA and ATTR CA.

Effects of global longitudinal strain and total scar burden on response to cardiac resynchronization therapy in patients with ischaemic dilated cardiomyopathy.

AIMS: To evaluate whether quantification of the extent of scarred left ventricular (LV) tissue by speckle-tracking strain echo (2DSE) can predict response to cardiac resynchronization therapy (CRT) in patients with ischaemic dilated cardiomyopathy (DCM). METHODS AND RESULTS: Forty-five patients (58.3 +/- 8.3 years; 24 males) with ischaemic DCM scheduled for CRT, and 25 controls were studied. A week before implantation all the patients underwent standard Doppler echo, 2DSE, and contrast-enhanced magnetic resonance (MR). Clinical and echocardiographic evaluation was repeated 6 months after CRT. The patients were considered as responders to CRT if LV end-systolic volume decreased by 15%. In DCM patients, LV ejection fraction was 29.2 +/- 5.1%. By evaluating the 765 segments with MR, subendocardial infarct was identified in 17.0% and transmural infarct in 18.3%. With 2DSE, the average global longitudinal strain (GLS) was -23.1 +/- 3.6% in controls and -15.1 +/- 5.1% in DCM (P = 0.001). GLS showed a close correlation with total scar burden using MR (r = 0.64, P < 0.001). At follow-up, patients were subdivided into responders (n = 30; 66.7%) and non-responders (n = 15; 33.3%) to CRT. GLS was significantly different in non-responders than in responders (GLS: -10.4 +/- 5.1 in non-responders vs. -18.4 +/- 14% in responders, P < 0.001). In a multivariable analysis, GLS (P < 0.0001) and radial intraventricular dyssynchrony (P < 0.001) were powerful independent determinants of response to CRT. CONCLUSION: GLS is strongly associated with total scar burden assessed by MR, and is an excellent independent predictor of response to CRT.

Effect of right ventricular apical pacing in survivors of myocardial infarction.

BACKGROUND: Much information is available regarding the possible negative effects of long-term right ventricular (RV) apical pacing, which may cause worsening of heart failure. However, very limited data are available regarding the effects of RV pacing in patients with a previous myocardial infarction (MI). METHODS AND RESULTS: We screened 115 consecutive post-MI patients and matched a group of 29 pacemaker (PM) recipients with a group of 49 unpaced patients, for age, left ventricular (LV) ejection fraction, and site of MI. During a median follow-up of 54 months, echocardiograms showed a decrease in LV ejection fraction in the paced group, from 51 +/- 10 to 39 +/- 11 (P < 0.01), and a minimal change in the unpaced group, from 57 +/- 8 to 56 +/- 7 (P = 0.98). Similar change was observed in systolic and diastolic diameters and volumes. CONCLUSIONS: The study showed that, in post-MI patients, RV apical pacing was associated with a worsening of LV function, suggesting that, among MI survivors, the need for a PM is a marker of worse outcome.

Significant functional mitral regurgitation affects left atrial function in heart failure patients: haemodynamic correlations and prognostic implications.

AIMS: Functional mitral regurgitation (FMR) is a well-known pathophysiological factor in heart failure (HF) patients, and left atrial function (LAF) is a novel determinant of clinical status and outcome in this setting. However, little is known about the pathophysiological role of FMR on LAF in HFrEF patients. Aim of this study is to explore the possible interplay between the severity of FMR and LAF in heart failure with reduce ejection fraction (HFrEF) patients and their possible consequences. METHODS AND RESULTS: We studied 97 consecutive patients with FMR classified in two groups: mild-to-moderate MR ore less (FMR group, n = 38) and moderate-to-severe or more (SFMR group, n = 59). Using the phasic method, left atrial contractile, conduit, reservoir, and total emptying function (TLAEF) were calculated to assess LAF. SFMR group showed significantly lower values of LAF compared to FMR group. LA dysfunction (LA-dys) was defined for TLAEF values below the median and groups divided in four subgroups based on its presence. Patient with LA-Dys in SFMR group showed a worse clinical status, higher incidence of right ventricular dysfunction (RV-Dys), and pulmonary hypertension (PH), and a significant worse clinical survival compared to all other groups. CONCLUSION: In our study, the survival was significantly lower in SFMR/LA-Dys+ group. Furthermore, LA-Dys was strongly related with worse clinical status and higher incidence of PH and RV-Dys. These results suggest that in patients with SFMR and HFrEF, LA-Dys may represent both a marker of more advanced disease and a novel prognostic factor.

Anesthesiological Management in Transcatheter Mitral Valve Repair With MitraClip: Beyond the EVEREST Criteria.

Percutaneous mitral valve repair with the MitraClip system recently emerged as a viable and less invasive therapeutic option in patients with severe mitral regurgitation deemed to be high-risk surgical candidates. Mitral valve morphology and geometry features are key elements for MitraClip eligibility. In the setting of functional mitral regurgitation, the presence of a leaflet coaptation gap due to advanced left ventricle remodeling can be a potential exclusion criterion for MitraClip therapy. In this article, the authors present a case of successful MitraClip implantation in a patient with severe functional mitral regurgitation and a significant coaptation gap. Periprocedural and intraoperative pharmacological and anesthesiological management were fundamental for successful grasping and procedural success.

Infective Endocarditis: Echocardiographic Imaging and New Imaging Modalities.

Infective endocarditis (IE) is a rare disease with a significant impact and an increasing mortality despite earlier diagnosis and surgical intervention. It is related to several and the main etiological agents are the Gram-positive cocci. The new guidelines propose new diagnostic criteria that consider the potentiality on integrated multimodality imaging. Echocardiography (TTE) plays a key role for the diagnosis of IE and must be performed as soon as IE is suspected. It allows to identify vegetation, abscess, new dehiscence of prosthetic valve and assesses the number, size, shape, location, echogenicity and mobility of vegetations so it also useful for prediction embolic risk. Transesophageal echocardiography (TEE) is indicated when TTE is positive or non diagnostic, in case of suspected complications and when intracardiac device leads are present. We underline the increasing role of three-dimensional (3D) echocardiography in overcoming the limit of 2DTEE in selecting the maximum true diameter of irregular masses (ie, vegetation). We also underline the diagnostic value of multislice computed tomograpfy (MSCT), cerebral magnetic resonance (RMI) and nuclear imaging and also emphasize the emerging role of particular types of endocarditis specially Lead Endocarditis. The aim of this review is to provide an overview of the imaging techniques useful for the diagnosis and identification of any complications. In our opinion, the management of IE is complex, based on an "Endocarditis team " composed by several specialist and an integrated multimodality imaging is essential for the diagnostic approach.

A radial global dyssynchrony index as predictor of left ventricular reverse remodeling after cardiac resynchronization therapy.

BACKGROUND: Cardiac mechanical efficiency requires that opposing left ventricular regions are coupled both in shortening and lengthening during the same phase of cardiac cycle. Aim of this study was to evaluate whether global measures of mechanical dyssynchrony are able to predict reverse remodeling of the left ventricle in patients receiving cardiac resynchronization therapy (CRT). METHODS: Sixty-two patients underwent a clinical examination, including New York Heart Association class evaluation and 6-minute walking distance and both echocardiographic study before and 6 months after CRT. Intraventricular dyssynchrony was evaluated by two-dimensional strain echocardiography, measuring the amount of uncoordinated contraction and relaxation between septum and free wall for both longitudinal and radial function and was presented as the longitudinal global dyssynchrony index (LGDI) and the radial global dyssynchrony index (RGDI). Reverse remodeling was defined by a left ventricular end systolic volume reduction >or= 15%. RESULTS: After CRT 39 patients showed reverse remodeling. In this group, RGDI (0.74 +/- 0.26 vs 0.32 +/- 0.30; P = 0.0001) and LGDI (0.52 +/- 0.28 vs 0.30 +/- 0.24; P = 0.002) were significantly higher than in nonresponders. A receiver-operating characteristic curve analysis showed that RGDI >0.47 and LGDI >0.34 had a sensitivity and a specificity to predict reverse remodeling of 87% and 74%, 82%, and 74%, respectively. Stepwise forward multiple logistic regression analysis showed that RGDI (O.R.:13.4; 95%C.I.:4.2-120.5; P < 0.0001) was an independent determinant of a positive response to CRT. CONCLUSION: A radial global dyssynchrony index predicts left ventricular reverse remodeling after CRT.

Presence of left ventricular contractile reserve, evaluated by means of dobutamine stress-echo test, is able to predict response to cardiac resynchronization therapy.

INTRODUCTION: We evaluated whether the dobutamine stress-echo test can select responders to cardiac resynchronization therapy (CRT). Up to 50% of patients do not respond to CRT. Lack of response may be due to a significant amount of scar or fibrotic tissue at myocardial level. METHODS AND RESULTS: We studied 42 CRT patients. After clinical and echocardiographic evaluation, all patients underwent a dobutamine stress-echo test to assess contractile reserve. Cut-off for the test was an increase of 25% of the left ventricular ejection fraction. Patients were implanted with a CRT-defibrillator and followed up at 6 months. Cut-off for CRT response was a reduction of 15% of left ventricular end-systolic volume. Twenty-five patients responded to CRT; all of them showed presence of contractile reserve. The test showed a sensitivity of 100% and a specificity of 88%. CONCLUSION: Contractile reserve was a strong predictive factor of response to CRT in the studied population.

Transcatheter Aortic Valve Replacement and Cardiac Resynchronization Therapy in Cancer-Related Cardiotoxicity.

Cardiotoxicity related to antineoplastic agents is a rising and growing issue, therefore early recognition and prompt management can impact on the overall prognosis of cancer patients. We report the case of a 70-year-old woman without cardiovascular risk factors, with a medical history of non-Hodgkin lymphoma and chronic myeloid leukemia treated with chemotherapy and radiotherapy, who underwent transcatheter aortic valve replacement for severe aortic stenosis and cardiac resynchronization therapy for further development of complete left bundle branch block, with a significant improvement of her functional status and left ventricle systolic function in a long-term follow-up.

Effect of pacing the right ventricular mid-septum tract in patients with permanent atrial fibrillation and low ejection fraction.

INTRODUCTION: Permanent right ventricular (RV) pacing leads have been traditionally implanted in the right ventricular apex (RVA). Nowadays, some deleterious effects of RVA pacing have been recognized. The aim of this study was to evaluate the effect of different sites of RV pacing in patients with permanent atrial fibrillation (AF) and low ejection fraction (LEF) needing a pacemaker (PM) implantation. METHODS: Two hundred seventy-three patients with permanent AF and EF <30% underwent a one-chamber rate responsive (VVIR) PM implant procedure. Patients were divided into two groups: Group A, including 113 patients with the pacing lead tip placed in the RV mid-septum, and Group B of 120 patients with the pacing lead tip placed at the apex of RV. All patients had clinical and Echo control after 1, 3, 6, 12, and 18 months after PM implantation to assess New York Heart Association (NYHA) class and EF. RESULTS: After 18 months, NYHA class changed in Group A from 2.9 +/- 0.4 at implant to 1.7 +/- 0.3 at 18 months (P = 0.01), and in Group B from 3.0 +/- 0.5 at implant to 3.3 +/- 0.6 at 18 months (P = n.s.). EF increased in Group A: 28 +/- 2% at implant, 33 +/- 1% at 18 months (P = 0.0125), while no significant changes were observed in Group B: at implant 27 +/- 2%, 26 +/- 2% at 18 months (P = n.s.). CONCLUSION: The present study suggests that more physiological pacing from the RV sept can improve EF and quality of life (QoL) in patients with permanent AF and low EF needing a PM.

Incremental diagnostic value of ultrasonographic assessment of coronary flow reserve with high-dose dipyridamole in patients with acute coronary syndrome.

BACKGROUND: Coronary flow reserve (CFR) assessment by transthoracic Doppler echocardiography has been found to be useful in subjects with suspected coronary artery disease. An important clinical question is whether such technique can be successfully applied in patients admitted to the coronary care unit with an acute coronary syndrome to detect a significant left anterior descending (LAD) disease. METHODS: One hundred fifty-nine patients with acute coronary syndrome (93 patients with unstable angina, 66 with acute inferior or lateral myocardial infarction) were included in the present analysis. Patients underwent a high-dose dipyridamole stress (0.84 mg/kg) with combined assessment of CFR in the LAD and regional wall motion. Blood flow velocities were recorded in the mid-distal portion of the LAD using a digital ultrasonographic system and CFR was calculated as the ratio of hyperemia-induced peak diastolic velocity to resting peak diastolic flow velocity. All patients underwent coronary angiography and a significant LAD stenosis was classified for lumen narrowing > or = 70%. RESULTS: Adequate Doppler recordings in the LAD were obtained in 92% of patients. A contrast agent was used in the 39% of examinations. No major adverse reaction occurred in any patient. A receiving operating characteristic curve showed that a CFR value < 1.9 had a sensitivity of 85%, a specificity of 87%, a positive predictive value of 71%, a negative predictive value of 94% and a diagnostic accuracy of 86% for identifying a significant LAD stenosis. The area under the receiving operating characteristic curve computed for CFR was significantly higher than for wall motion score index (p < 0.001). In a stepwise forward, multiple logistic regression analysis, both CFR (OR = 4.8, 95% C.I. 3.7-5.3; p < 0.00001) and the wall motion score index for the LAD territory (OR = 4.2, 95% C.I. 2.6-6.8; p < 0.0001) were independent determinants of LAD stenosis > or = 70%. CONCLUSION: Early assessment of CFR by transthoracic Doppler echocardiography is feasible and safe and provides additional information to identify subjects with acute coronary syndrome and significant LAD stenosis.

Usefulness of transthoracic color Doppler echocardiography for the identification of left anterior descending coronary artery stenosis.

We briefly describe our experience with transthoracic Doppler echocardiography for the direct evaluation of mid-distal left anterior descending coronary artery (LAD) stenosis. Three patients with previous myocardial infarction, scheduled for coronary flow reserve evaluation, underwent Doppler analysis of the mid-distal LAD. In all 3 cases, the mid-distal LAD stenosis was accurately quantified by the Doppler spectrum as confirmed by quantitative coronary angiography. Our study demonstrated the feasibility of transthoracic Doppler echocardiography in the discrimination of significant and non-significant mid-distal LAD stenosis. Limitations of such a technique could be related to the variable coronary anatomy and to the severity of the atherosclerotic process.

Recoordination of opposing walls drives the response to cardiac resynchronization therapy: a longitudinal study using a strain discoordination index.

BACKGROUND AND AIMS: Intraventricular dyssynchrony has traditionally been studied by means of contraction delays between different myocardial segments. Recently, the discoordination of opposing wall contraction throughout the cardiac cycle has been proposed as a more faithful predictor of response. Aim of the current study was to evaluate which parameters - mechanical dyssynchrony or discoordination - normalize with left ventricular response to cardiac resynchronization therapy (CRT). METHODS: Cardiac mechanics were analysed before and after 6 months of CRT in 53 patients with left bundle branch block and advanced heart failure. Discoordination was quantified by means of the transverse strain discoordination index (TSDI) at basal and mid-ventricular segments; this index takes into account the percentage of time in the cardiac cycle in which cardiac deformation (transverse strain) of the two opposing walls occurs in noncoordinated directions. Dyssynchrony indices included septal to lateral peak-to-peak transverse strain delay and the standard deviation of time to peak tissue velocity in 12 mid-basal segments (Yu index). RESULTS: Around 63% of patients met the response criteria. Several baseline indices were predictive of reverse remodelling; TSDI at the mid-ventricular level demonstrated the best accuracy. Time from Q to peak velocity and strain tended to increase in all explored myocardial segments; despite a trend towards a decrease in septal-to-lateral strain delay, the latter decreased equally in responders and in nonresponding patients. Yu index decreased in responders more than in nonresponders, with borderline significance. Basal and medium TSDI remained unchanged in nonresponders and consistently normalized in patients who responded to CRT. The changes in TSDI were significantly correlated with improvements in left ventricular end-systolic volume and ejection fraction; the strongest correlation was observed for changes in TSDI measured at the mid-ventricular level. CONCLUSION: Left ventricular reverse remodelling after CRT is accompanied by the recoordination of opposite-wall contraction, as testified by changes in mid-ventricular TSDI, which also reveals as a very good predictor of response. On the contrary, changes of segmental peak-to-peak delays (dyssynchrony indices) fail to capture the complex nature of left ventricular response to CRT.

Left atrium remodeling after acute myocardial infarction (results of the GISSI-3 Echo Substudy).

To evaluate the existence, timing, and determinants of post-infarction left atrial remodeling, we studied a subgroup of 514 patients from the Third Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico Echo Substudy who underwent 4 serial 2-dimensional echocardiograms up to 6 months after acute myocardial infarction. This study is the first to demonstrate, in a large series of patients, the existence of early and late left atrial remodeling after low-risk acute myocardial infarction and the relation of left atrial remodeling to left ventricular remodeling.

Usefulness of the mitral/aortic flow velocity integral ratio as a screening method to identify patients with hemodynamically significant mitral regurgitation.

OBJECTIVE: We sought to test the value of a simple Doppler index, the mitral/aortic flow velocity integral ratio (MAVIR), as a screening method to identify patients with hemodynamically significant mitral regurgitation (MR). METHODS: Included in the study were 91 patients (mean age 61 +/- 14 years; 54% men) with echocardiographically diagnosed MR. The cause was organic in 23 patients and ischemic/functional in 68. MR degree was assessed by 2 quantitative echocardiographic measures: the regurgitant fraction and the regurgitant orifice area. RESULTS: A good correlation was found between MAVIR and both regurgitant fraction (r = 0.75) and orifice (r = 0.60). When we divided patients into 3 groups on the basis of the regurgitant fraction, used as reference standard, MAVIR significantly increased in proportion to MR severity (0.7 +/- 0.1 for mild MR vs 1.1 +/- 0.2 for moderate and 1.4 +/- 0.3 for severe regurgitation; P <.0001). A ratio > 1 identified 28 of 30 patients with severe MR (regurgitant fraction > 60%), whereas all patients with mild MR (regurgitant fraction < 40%) had a ratio < 1. Using a regurgitant orifice >or= 40 mm(2) as threshold for severe MR, a significant difference in MAVIR was also present among patients who had severe MR compared with those having mild and moderate regurgitation (P <.0001). CONCLUSIONS: These findings suggest that MAVIR is a sensitive index, potentially widely applicable in clinical practice as a screening parameter for identifying patients with hemodynamically significant MR.