American Society of Echocardiography Algorithm for Degenerative Mitral Regurgitation: Comparison With CMR.

OBJECTIVES: The purpose of this study was to compare the American Society of Echocardiography (ASE) algorithm for assessing mitral regurgitation (MR) to cardiac magnetic resonance (CMR) and left ventricular (LV) remodeling following mitral intervention. BACKGROUND: The ASE recommends integrating multiple echocardiographic parameters for assessing MR. The ASE guidelines include an algorithm that weighs the parameters and highlights those considered indicative of definitely mild or definitely severe MR. METHODS: We prospectively enrolled 152 (age 62 ± 13 years; 59% male) patients with degenerative MR who underwent ASE algorithm-guided echocardiographic and CMR grading of MR severity. Using the ASE algorithm, patients were graded as definitely mild, grade I, grade II, grade III, grade IV, or definitely severe MR. CMR MR volume was graded as mild (<30 mL), grade II moderate (30-44 mL), grade III moderate (45-59 mL), or severe (≥60 mL). A subgroup of 63 patients underwent successful mitral intervention, of whom 48 had postintervention CMR. RESULTS: Only 52% of patients with definitely severe MR by the ASE algorithm had severe MR by CMR, and 10% had mild MR by CMR. There was an increase in post mitral intervention LV reverse remodeling with worsening MR severity using CMR (P < 0.0001) but not the ASE algorithm (P = 0.07). Severe MR by CMR was an independent predictor of post mitral intervention LV reverse remodeling and definitely severe MR by the ASE algorithm was not. CONCLUSIONS: In patients with degenerative MR, agreement between CMR and the ASE algorithm was suboptimal. Severe MR by CMR was an independent predictor of post mitral intervention LV reverse remodeling, whereas definitely severe MR by the ASE algorithm was not. These findings suggest an important role for CMR in surgical decision making in degenerative MR. (Comparison Study of Echocardiography and Cardiovascular Magnetic Resonance Imaging in the Assessment of Mitral and Aortic Regurgitation; NCT04038879).

Characterization of Primary Mitral Regurgitation With Flail Leaflet and/or Wall-Impinging Flow.

BACKGROUND: Echocardiography guidelines note that a flail leaflet is a specific criterion for severe mitral regurgitation (MR) and that regurgitant severity is underestimated in wall-impinging jets (Coanda effect). Both findings are often considered to be pathognomonic of severe MR. OBJECTIVES: In this study, the authors sought to determine the association of flail leaflet and Coanda effect with MR severity quantified by means of cardiac magnetic resonance (CMR). METHODS: The authors enrolled 158 consecutive patients with primary MR according to echocardiography and CMR. The presence of a flail leaflet or Coanda was determined for each patient. CMR regurgitant volume (RV) and regurgitant fraction (RF) were quantified for all patients. RESULTS: There were 55 patients (35%) with a flail leaflet, 52 (33%) with Coanda, and 22 (14%) with a flail leaflet and Coanda. The mean CMR mitral RV and RF progressively increased in patients without a Coanda or flail, a Coanda, a flail, or a Coanda and a flail (RV: 28 ± 21 mL vs 43 ± 23 mL vs 58 ± 29 mL vs 64 ± 25 mL [P < 0.001]; RF: 25% ± 16% vs 34% ± 14% vs 41% ± 12% vs 45% ± 12% [P < 0.001]). With the use of CMR RV, 35%, 46%, and 59% of patients had severe MR with the presence of a Coanda, flail leaflet, or both, respectively. With the use of CMR RF, 25%, 31%, and 40% of patients had severe MR with the presence of a Coanda, flail leaflet, or both, respectively. CONCLUSIONS: While the presence of a flail leaflet and Coanda effect on echocardiography are associated with higher regurgitant volumes and fractions, they are frequently not associated with severe MR as assessed by means of CMR. (Comparison Study of Echocardiography and Cardiovascular Magnetic Resonance Imaging in the Assessment of Mitral and Aortic Regurgitation; NCT04038879).

Cardiovascular Magnetic Resonance in Valvular Heart Disease-Related Heart Failure.

Patients with valvular heart disease-related heart failure are unable to pump enough blood to meet the body's needs. Magnetic resonance imaging (MRI) can play an important role by identifying these patients and distinguishing them from patients whose valvular disease is not the cause of their heart failure. Heart failure is a major public health problem, with a prevalence of 5.8 million people in the United States and more than 223 million people worldwide. This article focuses on the diagnostic and prognostic value of MRI patients with valvular causes of heart failure.

Usefulness of Mitral Regurgitant Volume Quantified Using Magnetic Resonance Imaging to Predict Left Ventricular Remodeling After Mitral Valve "Correction".

MRI studies have shown a tight correlation between mitral regurgitant volume and left ventricular end-diastolic volume (LV EDV) in patients with primary chronic mitral regurgitation (MR). They have also shown a tight correlation between regurgitant volume and the decrease in LVEDV following mitral valve surgery. The purpose of this study is to validate an empiric calculation that can be used preoperatively to predict the amount of left ventricular remodeling following mitral valve correction. This is a prospective multicenter study of 63 (61 ± 13 years, male 65%) patients who underwent an MRI before and after mitral valve correction. Pre and postmitral valve correction ventricular volumes and ejection fractions were quantified. The predicted change in LV EDV was empirically calculated as mitral regurgitant volume/left ventricular ejection fraction. The observed change in LV EDV was compared to the predicted change in LV EDV. The LVEDV decreased in 61 (97%) patients following mitral valve correction (237 ± 66 ml vs 164 ± 46 ml, p <0.0001). Correlation between the observed and predicted change in LVEDV was good for the entire cohort (r = 0.77, p <0.0001) and excellent in patients with <10 ml of residual MR (r = 0.87, p <0.0001). This tight correlation was seen in both patients with primary (0.86, p <0.0001) and secondary MR (0.97, p <0.0001) and <10 ml of residual MR. Multivariate predictors of LV remodeling were MR volume, primary MR, and LVESV. In conclusion cardiac MRI volumetric measurements accurately predict LV remodeling following mitral valve correction. This finding supports the notion that MRI accurately quantifies the severity of chronic mitral regurgitation and a cardiac MRI should be strongly considered before mitral valve correction.

The Effect of Systolic Variation of Mitral Regurgitation on Discordance Between Noninvasive Imaging Modalities.

OBJECTIVES: This study sought to assess the impact of systolic variation of mitral regurgitation (MR) has on discordance between echocardiography and magnetic resonance imaging (MRI). BACKGROUND: Studies have shown discordance between echocardiography and MRI when assessing the severity of MR. Contributing factors to this discordance may include the systolic variation of MR and the use of the color Doppler jet at a single point in time as the basis of many echocardiographic methods. METHODS: This analysis included 117 patients (62 ± 14 years of age; 58% male) with MR who underwent echocardiographic and MRI evaluation. Discordance was defined as the difference between the grades of MR (mild, moderate, or severe) by MRI and echocardiography. For each patient, 2 echocardiographic methods, the continuous wave time index and the color Doppler time index, and 1 MRI method, the systolic variation score (SVS), were measured to quantify systolic variation of MR. RESULTS: There was absolute agreement between echocardiography and MRI in 47 (40%) patients, a 1-grade difference in 54 (46%) patients, and a 2-grade difference in 16 (14%) patients. Only the SVS significantly differed between patients with and without discordance (0.60 ± 0.23 vs. 0.47 ± 0.21; p = 0.003). On receiver-operating characteristic analysis SVS had moderate predictive power of discordance (area under the curve: 0.67; p = 0.003), with an SVS of 53 having a sensitivity of 61% and a specificity of 65% to predict discordance. CONCLUSIONS: Discordance between MRI and echocardiographic assessment of MR severity is associated with systolic variation of MR as quantified by MRI using the SVS. Continuous wave Doppler and the presence of color Doppler were not correlated with discordance. This study highlights an advantage of MRI. Namely, it does not rely on a single point in time to determine MR severity. Because systolic variation had only moderate sensitivity and specificity for predicting discordance, other factors are also responsible for the discordance between the 2 techniques.

A Comparative Assessment of Echocardiographic Parameters for Determining Primary Mitral Regurgitation Severity Using Magnetic Resonance Imaging as a Reference Standard.

BACKGROUND: The American Society of Echocardiography (ASE) guidelines suggest the use of several echocardiographic methods to assess mitral regurgitation severity using an integrated approach, without guidance as to the weighting of each parameter. The purpose of this multicenter prospective study was to evaluate the recommended echocardiographic parameters against a reference modality and develop and validate a weighting for each echocardiographic measure of mitral regurgitation severity. METHODS: This study included 112 patients who underwent evaluation with echocardiography and magnetic resonance imaging (MRI). Echocardiographic parameters recommended by the ASE were included and compared with MRI-derived regurgitant volume (MRI-RV). RESULTS: Echocardiographic parameters that correlated best with MRI-RV were proximal isovelocity surface area (PISA) radius (r = 0.65, P < .0001), PISA-derived effective regurgitant orifice area (r = 0.65, P < .0001), left ventricular end-diastolic volume (r = 0.56, P < .0001), and PISA-derived regurgitant volume (r = 0.52, P < .0001). In the linear regression models PISA-derived effective regurgitant orifice area, PISA-derived regurgitant volume, left ventricular end-diastolic volume, and the presence of a flail leaflet independently predicted MRI-RV. CONCLUSION: Echocardiographic parameters of mitral regurgitation as recommended by the ASE had moderate correlations with MRI-RV. The best predictors of MRI-RV were PISA-derived effective regurgitant orifice area, PISA-derived regurgitant volume, left ventricular end-diastolic volume, and the presence of a flail leaflet, suggesting that these parameters should be weighted more heavily than other echocardiographic parameters in the application of the ASE-recommended integrated approach.

Use of Cardiac Magnetic Resonance Imaging in Assessing Mitral Regurgitation: Current Evidence.

Accurate quantification of regurgitant volume is a central component to the management of mitral regurgitation. Cardiac magnetic resonance imaging (CMR) accurately quantifies mitral regurgitation as the difference between left ventricular stroke volume and forward stroke volume using steady state free precession and phase contrast imaging. The CMR measurement of mitral regurgitant volume is reproducible and can quantify mitral regurgitation in patients without regard to regurgitant jet morphology, such as patients with multiple and eccentric jets. It can be used to quantify regurgitant volume in patients with multiple valve lesions and concomitant intracardiac shunts without the use of intravenous contrast. Studies have highlighted the accuracy and reproducibility of CMR in quantifying mitral regurgitation and have begun to link CMR to clinical outcomes.

Assessing the Risks Associated with MRI in Patients with a Pacemaker or Defibrillator.

BACKGROUND: The presence of a cardiovascular implantable electronic device has long been a contraindication for the performance of magnetic resonance imaging (MRI). We established a prospective registry to determine the risks associated with MRI at a magnetic field strength of 1.5 tesla for patients who had a pacemaker or implantable cardioverter-defibrillator (ICD) that was "non-MRI-conditional" (i.e., not approved by the Food and Drug Administration for MRI scanning). METHODS: Patients in the registry were referred for clinically indicated nonthoracic MRI at a field strength of 1.5 tesla. Devices were interrogated before and after MRI with the use of a standardized protocol and were appropriately reprogrammed before the scanning. The primary end points were death, generator or lead failure, induced arrhythmia, loss of capture, or electrical reset during the scanning. The secondary end points were changes in device settings. RESULTS: MRI was performed in 1000 cases in which patients had a pacemaker and in 500 cases in which patients had an ICD. No deaths, lead failures, losses of capture, or ventricular arrhythmias occurred during MRI. One ICD generator could not be interrogated after MRI and required immediate replacement; the device had not been appropriately programmed per protocol before the MRI. We observed six cases of self-terminating atrial fibrillation or flutter and six cases of partial electrical reset. Changes in lead impedance, pacing threshold, battery voltage, and P-wave and R-wave amplitude exceeded prespecified thresholds in a small number of cases. Repeat MRI was not associated with an increase in adverse events. CONCLUSIONS: In this study, device or lead failure did not occur in any patient with a non-MRI-conditional pacemaker or ICD who underwent clinically indicated nonthoracic MRI at 1.5 tesla, was appropriately screened, and had the device reprogrammed in accordance with the prespecified protocol. (Funded by St. Jude Medical and others; MagnaSafe ClinicalTrials.gov number, NCT00907361 .).

Utilization and likelihood of radiologic diagnostic imaging in patients with implantable cardiac defibrillators.

PURPOSE: To examine imaging utilization in a matched cohort of patients with and without implantable cardioverter defibrillators (ICD) and to project magnetic resonance imaging (MRI) utilization over a 10-year period. MATERIALS AND METHODS: The Truven Health MarketScan Commercial claims and Medicare Supplemental health insurance claims data were used to identify patients with continuous health plan enrollment in 2009-2012. Patients with ICDs were identified using ICD-9 and CPT codes, and matched to patients with the same demographic and comorbidity profile, but no record of device implantation. Diagnostic imaging utilization was compared across the matched cohorts, in total, by imaging categories, and in subpopulations of stroke, back pain, and joint pain. MRI use in the nonimplant group over the 4-year period was extrapolated out to 10 years for ICD-indicated patients. RESULTS: A cohort of 18,770 matched patients were identified; average age 65.5 ± 13.38 and 21.9% female. ICD patients had significantly less MRI imaging (0.23 0.70 SD vs. 0.00 0.08 SD, P < 0.0001) than nonimplant patients. Among patients with records of stroke/transient ischemic attack (TIA) (ICD 5%, nonimplant 4%) and accompanying diagnostic imaging, 44% of nonimplant patients underwent MRI vs. 1% of ICD patients (P < 0.0001). Forecast models estimated that 53% to 64% of ICD-eligible patients may require an MRI within 10 years. CONCLUSION: MRI utilization is lower in ICD patients compared to nonimplant patients, yet the burden of incident stroke/TIA, back, and joint pain suggests an unmet need for MR-conditional devices.

Discordance between echocardiography and MRI in the assessment of mitral regurgitation severity: a prospective multicenter trial.

BACKGROUND: The decision to undergo mitral valve surgery is often made on the basis of echocardiographic criteria and clinical assessment. Recent changes in treatment guidelines recommending surgery in asymptomatic patients make the accurate assessment of mitral regurgitation (MR) severity even more important. OBJECTIVES: The purpose of this study was to compare echocardiography and magnetic resonance imaging (MRI) in the assessment of MR severity using the degree of left ventricular (LV) remodeling after surgery as the reference standard. METHODS: In this prospective multicenter trial, MR severity was assessed in 103 patients using both echocardiography and MRI. Thirty-eight patients subsequently had isolated mitral valve surgery, and 26 of these had an additional MRI performed 5 to 7 months after surgery. The pre-surgical estimate of regurgitant severity was correlated with the postoperative decrease in LV end-diastolic volume. RESULTS: Agreement between MRI and echocardiographic estimates of MR severity was modest in the overall cohort (r = 0.6; p < 0.0001), and there was a poorer correlation in the subset of patients sent for surgery (r = 0.4; p = 0.01). There was a strong correlation between post-surgical LV remodeling and MR severity as assessed by MRI (r = 0.85; p < 0.0001), and no correlation between post-surgical LV remodeling and MR severity as assessed by echocardiography (r = 0.32; p = 0.1). CONCLUSIONS: The data suggest that MRI is more accurate than echocardiography in assessing the severity of MR. MRI should be considered in those patients when MR severity as assessed by echocardiography is influencing important clinical decisions, such as the decision to undergo MR surgery.

Usefulness of the Left Anterior Descending Artery Wrapping Around the Left Ventricular Apex to Predict Adverse Clinical Outcomes in Patients With Anterior Wall ST-Segment Elevation Myocardial Infarction (an INFUSE-AMI Substudy).

The relation between left anterior descending coronary artery (LAD) anatomic features and clinical outcomes in patients with anterior ST-segment elevation myocardial infarction has not been fully investigated. The Intracoronary Abciximab and Aspiration Thrombectomy in Patients With Large Anterior Myocardial Infarction (INFUSE-AMI) trial randomized 452 patients with anterior ST-segment elevation myocardial infarctions who underwent mechanical revascularization to intralesional abciximab versus no abciximab and to manual thrombus aspiration versus no aspiration. The primary end point was infarct size (percentage left ventricular mass) on contrast magnetic resonance imaging at 30 days. "Wraparound LAD" was defined as an LAD reaching the apex and supplying the apical inferior aspect of the heart. Among complete data available in 338 patients, 258 (76.3%) had wraparound LADs. Global infarct size (17.4% vs 16.1%, p = 0.64) and the left ventricular ejection fraction (49.7% vs 48.7%, p = 0.98) by contrast magnetic resonance imaging at 30 days were comparable between patients with and those without wraparound LADs. Regional apical anterior infarct size was comparable (59.5% vs 55.8%, p = 0.559) between the groups; however, apical septal (61.3% vs 48.9%, p = 0.005), apical inferior (19.0% vs 3.7%, p <0.0001), and apical lateral (12.2% vs 4.8%, p = 0.0584) infarct sizes were larger in patients with wraparound LADs compared with those with nonwraparound LADs. The incidence of new-onset severe heart failure at 1 year was significantly higher in patients with compared with those without wraparound LADs (6.3% vs 0%, p = 0.02). In conclusion, in patients with anterior ST-segment elevation myocardial infarctions, as compared with the LAD not supplying the inferior aspect of the heart, a wraparound LAD was associated with a larger left ventricular apex infarct size, resulting in worse adverse events at 1 year.

An easy and reproducible parameter for the assessment of the pressure gradient in patients with aortic stenosis disease: A magnetic resonance study.

AIM: Cardiovascular magnetic resonance (CMR) has been increasingly used as an alternative method to evaluate the severity of aortic stenosis. The aim of our study was to evaluate whether the indirect measurement of the aortic gradient (Calc-PG), derived from Gorlin's formula, is a reproducible parameter for gradient assessment. Then, we evaluated if this parameter is correlated with left ventricular hypertrophy, considered as a marker of severity of aortic stenosis, better than phase-contrast sequences-derived pressure gradient (PC-PG) and aortic valve area. METHODS: Forty-one patients with isolated aortic stenosis underwent CMR. Calc-PG was obtained from the formula (cardiac output/aortic valve area)(2), and it was compared to PC-PG. RESULTS: We found that the Calc-PG has higher correlation with left ventricle mass than PC-PG (r(2) 0.44, p<0.001 vs. r(2) 0.26, p<0.01), also after multivariate analysis adjusting for age, gender and hypertension (p<0.001). Furthermore, Calc-PG was more reproducible than PC-PG. The receiver operating characteristic comparison curve analysis showed that Calc-PG has a significantly higher ability to describe the presence of left ventricular hypertrophy than PC-PG (area under the curve 0.85, 95% CI 0.70-0.94, p<0.0001 vs. 0.74, 95% CI 0.58-0.87, p=0.03). CONCLUSIONS: We propose that transaortic gradient indirectly calculated by using the simplified Gorlin's equation could be an alternative method to assess the severity of aortic stenosis.

A novel technique to quantify the instantaneous mitral regurgitant rate.

BACKGROUND: The systolic variation of mitral regurgitation (MR) is a pitfall in its quantification. Current recommendations advocate using quantitative echocardiographic techniques that account for this systolic variation. While prior studies have qualitatively described patterns of systolic variation no study has quantified this variation. METHODS: This study includes 41 patients who underwent cardiovascular magnetic resonance (CMR) evaluation for the assessment of MR. Systole was divided into 3 equal parts: early, mid, and late. The MR jets were categorized as holosystolic, early, or late based on the portions of systole the jet was visible. The aortic flow and left ventricular stroke volume (LVSV) acquired by CMR were plotted against time. The instantaneous regurgitant rate was calculated for each third of systole as the difference between the LVSV and the aortic flow. RESULTS: The regurgitant rate varied widely with a 1.9-fold, 3.4-fold, and 1.6-fold difference between the lowest and highest rate in patients with early, late, and holosystolic jets respectively. There was overlap of peak regurgitant rates among patients with mild, moderate and severe MR. The greatest variation of regurgitant rate was seen among patients with mild MR. CONCLUSION: CMR can quantify the systolic temporal variation of MR. There is significant variation of the mitral regurgitant rate even among patients with holosystolic MR jets. These findings highlight the need to use quantitative measures of MR severity that take into consideration the temporal variation of MR.

Intralesional abciximab and thrombus aspiration in patients with large anterior myocardial infarction: one-year results from the INFUSE-AMI trial.

BACKGROUND: Whether intralesional abciximab administration and thrombus aspiration confer clinical benefits to patients undergoing primary percutaneous coronary intervention for ST-segment-elevation myocardial infarction is controversial. METHODS AND RESULTS: A total of 452 patients with ST-segment-elevation myocardial infarction caused by proximal or mid left anterior descending artery occlusion undergoing primary percutaneous coronary intervention with bivalirudin anticoagulation were randomized in a 2×2 factorial design to bolus abciximab delivered locally at the infarct lesion site versus no abciximab and to manual thrombus aspiration versus no aspiration. Treatment with intralesional abciximab, thrombus aspiration, or both therapies compared with no active therapy before stent implantation resulted in lower 1-year rates of death (4.5% versus 10.4%; P=0.03), severe heart failure (4.2% versus 10.3%; P=0.02), and stent thrombosis (0.9% versus 3.8%; P=0.046). Between 30 days and 1 year of follow-up, treatment with intralesional abciximab compared with no abciximab was associated with a lower rate of death (1.4% versus 4.9%; P=0.04) and composite major adverse ischemic events (3.3% versus 7.8%; P=0.04), with nonsignificantly different overall 1-year rates of mortality, composite ischemic events, and heart failure-related events. Thrombus aspiration compared with no aspiration was associated with lower rates of new-onset severe heart failure between 30 days and 1 year (0.9% versus 4.5%; P=0.02) and of rehospitalization for heart failure from randomization to 1 year (0.9% versus 5.4%; P=0.0008), with nonsignificantly different rates of mortality. CONCLUSIONS: Intralesional abciximab and thrombus aspiration may have long-term benefits in patients with anterior ST-segment-elevation myocardial infarction presenting early after symptom onset and undergoing primary percutaneous coronary intervention with bivalirudin anticoagulation. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT00976521.

Clinical outcomes following a strategy of optimized medical management and selective "downstream" procedures following coronary computed tomography angiography.

BACKGROUND: Prior studies have shown a consistent relationship between coronary artery calcium (CAC) scores or the degree of coronary stenoses on coronary computed tomography angiography (CCTA) and all-cause mortality. Whether CCTA-targeted therapy, including intensive medical management, stress testing and/or invasive coronary angiography (ICA), can lead to a substantial reduction in adverse outcomes is not yet known. METHODS: We retrospectively analyzed 691 patients (55±13 years, male=63%) from a single medical practice who underwent a CAC scan and CCTA and were followed for a mean of 2.9±1.0 years. Of these, 416 (60%) patients were asymptomatic. All changes in medications, coronary risk factors (including lipids profiles), downstream testing, revascularization procedures, and clinical events (myocardial infarction and death) were recorded. RESULTS: Among our patients cohort 279 (40%) had no coronary artery disease. The most severe stenosis was <50% in 314 (46%) patients, 50-70% in 76 (11%) patients, and >70% in 22 (3%) patients. A high frequency of medical therapy was employed for those patients with any degree of stenosis, while stress testing was primarily applied for patients with >50% stenosis and ICA was primarily performed in those with >70% stenosis. Only two non-cardiovascular deaths and no cardiovascular deaths occurred during the follow-up period. CONCLUSIONS: Our findings support the hypotheses that among patients undergoing CCTA, comprehensive medical management, including targeted percutaneous coronary interventions and increasingly intensive medical therapy with progressively worse CCTA findings, can reduce event rates among patients with abnormal CCTA studies.