Practice gaps in the care of mitral valve regurgitation: Insights from the American College of Cardiology mitral regurgitation gap analysis and advisory panel.

BACKGROUND: The revised 2014 American College of Cardiology (ACC)/American Heart Association valvular heart disease guidelines provide evidenced-based recommendations for the management of mitral regurgitation (MR). However, knowledge gaps related to our evolving understanding of critical MR concepts may impede their implementation. METHODS: The ACC conducted a multifaceted needs assessment to characterize gaps, practice patterns, and perceptions related to the diagnosis and treatment of MR. A key project element was a set of surveys distributed to primary care and cardiovascular physicians (cardiologists and cardiothoracic surgeons). Survey and other gap analysis findings were presented to a panel of 10 expert advisors from specialties of general cardiology, cardiac imaging, interventional cardiology, and cardiac surgeons with expertise in valvular heart disease, especially MR, and cardiovascular education. The panel was charged with assessing the relative importance and potential means of remedying identified gaps to improve care for patients with MR. RESULTS: The survey results identified several knowledge and practice gaps that may limit implementation of evidence-based recommendations for MR care. Specifically, half of primary care physicians reported uncertainty regarding timing of intervention for patients with severe primary or functional MR. Physicians in all groups reported that quantitative indices of MR severity were frequently not reported in clinical echocardiographic interpretations, and that these measurements were not consistently reviewed when provided in reports. In the treatment of MR, nearly 30% of primary care physician and general cardiologists did not know the volume of mitral valve repair surgeries by their reference cardiac surgeons and did not have a standard source to obtain this information. After review of the survey results, the expert panel summarized practice gaps into 4 thematic areas and offered proposals to address deficiencies and promote better alignment with the 2014 ACC/American Heart Association valvular disease guidelines. CONCLUSION: Important knowledge and skill gaps exist that may impede optimal care of the patient with MR. Focused educational and practice interventions should be developed to reduce these gaps.

Value of interactive scanning for improving the outcome of new-learners in transcontinental tele-echocardiography (VISION-in-Tele-Echo) study.

BACKGROUND: Point-of-care (POC) echocardiography may be helpful for mass triage, but such a strategy requires adequately trained sonographers at the remote site. The aim of this study was to test the feasibility of using a novel POC echocardiography training program for improving physicians' imaging skills during preanesthetic cardiac evaluations performed in a community camp organized for treating cataract blindness. METHODS: Seventeen physicians were provided 6 hours of training in the use of POC echocardiography; nine were taught on site and eight were taught online through a transcontinental tele-echocardiography system. The trained physicians subsequently scanned elderly patients undergoing cataract surgery. The quality of images was graded, and agreement between local physicians' interpretations and Web-based interpretations by worldwide experts was compared. RESULTS: A total of 968 studies were performed, with 660 used for validating physicians' competence. Major cardiac abnormalities were seen in 136 patients (14.2%), with 32 (3.3%) deemed prohibitive to surgery in unmonitored settings. Although good-quality images were obtained more frequently by physicians trained on site rather than online (P = .03), there were no differences between the two groups in agreement with expert interpretations. The majority of physicians (70.6%) expressed satisfaction with the training (average Likert-type scale score, 4.24 of 5), with no difference seen between the two groups. The training resulted in significant improvements in self-perceived competence in all components of POC echocardiography (P < .001 for all). CONCLUSIONS: This study establishes the feasibility of using short-duration, one-on-one, personalized transcontinental tele-echocardiography education for wider dissemination of echocardiographic skills to local physicians in remote communities, essential for optimizing global cardiovascular health.

Application of speckle-tracking in the evaluation of carotid artery function in subjects with hypertension and diabetes.

BACKGROUND: Speckle-tracking enables direct tracking of carotid arterial wall motion. Timing intervals determined with carotid speckle-tracking and slopes calculated from carotid artery area versus cardiac cycle curves may provide further information on arterial function and stiffness. The proposed arterial stiffness parameters were examined in healthy controls (n = 20), nondiabetic patients with hypertension (n = 20), and patients with type 2 diabetes (n = 21). METHODS: Bilateral electrocardiographically gated ultrasonograms of the distal common carotid artery were acquired using a 12-MHz vascular probe. Four timing intervals were derived from speckle-tracked carotid arterial strain curves: (1) carotid predistension period, (2) peak carotid arterial strain time, (3) arterial distension period, and (4) arterial diastolic time. In addition, carotid artery area curves were recorded over the cardiac cycle and subdivided into four segments, S1 to S4, relating to arterial distention and contraction periods. RESULTS: Mean far wall predistension period and peak carotid arterial strain time were more delayed in patients with diabetes and hypertension than in controls. Global mean arterial distension period was prolonged and arterial diastolic time was shorter in patients with hypertension and diabetes than in controls. Slopes of segments S2 and S4 were markedly steeper in the combined group of patients with hypertension and diabetes compared with healthy controls (P = .03 and P = .02, respectively). CONCLUSIONS: Speckle-tracking-based measures of arterial stiffness may provide potential additive value in assessing vascular function in patients at risk for cardiovascular disease.

Segmental analysis of carotid arterial strain using speckle-tracking.

BACKGROUND: Increased arterial stiffness has been shown to be associated with aging and cardiovascular risk factors. Speckle-tracking algorithms are being used to measure myocardial strain. The aims of this study were to evaluate whether speckle-tracking could be used to measure carotid arterial strain (CAS) reproducibly in healthy volunteers and to determine if CAS was lesser in individuals with diabetes. METHODS: Bilateral electrocardiographically gated ultrasound scans of the distal common carotid arteries (three cardiac cycles; 14-MHz linear probe; mean frame rate, 78.7 ± 8.9 frames/sec) were performed twice (2-4 days apart) on 10 healthy volunteers to test repeatability. Differences in CAS between healthy subjects (n = 20) and patients with diabetes (n = 21) were examined. Peak CAS was measured in each of six equal segments, and averages of all segments (i.e., the global average), of the three segments nearest the probe, and of the three segments farthest from the probe (i.e., the far wall average) were obtained. RESULTS: Global CAS (intraclass correlation coefficient = 0.40) and far wall average (intraclass correlation coefficient = 0.63) had the greatest test-retest reliability. Global and far wall averaged CAS values were lower in patients with diabetes (4.29% [SE, 0.27%] and 4.30% [SE, 0.44%], respectively) than in controls (5.48% [SE, 0.29%], P = .001, and 5.58% [SE, 0.44%], P = .003, respectively). This difference persisted after adjustment for age, gender, race, and hemodynamic parameters. CONCLUSIONS: Speckle-tracking to measure CAS is feasible and modestly reliable. Patients with diabetes had lower CAS obtained with speckle-tracking compared with healthy controls.

Mitral annulus dynamics early after valve repair: preliminary observations of the effect of resectional versus non-resectional approaches.

BACKGROUND: Mitral repair is recommended for patients with significant organic mitral regurgitation (MR). The nonresectional dynamic mitral valve repair (NVR) method involves a complete flexible ring and artificial chordal insertion but without leaflet resection or annular plication. The aim of this study was to compare changes in mitral annular structure and function after the NVR technique with those after a resectional mitral valve repair (RVR) method, which involves leaflet resection and annuloplasty with a partial flexible ring. METHODS: Patients with organic severe MR undergoing mitral valve repair with either technique underwent three-dimensional transesophageal echocardiography before and after surgery. The mitral annulus was tracked offline and measured throughout the cardiac cycle. Mitral leaflet mobility was also measured. RESULTS: Fifteen patients underwent repair with NVR, and 13 underwent repair with RVR (age, 56 vs 61 years, respectively). Both operations reduced mitral annular area significantly (maximum area reduction, from 18.5 ± 4.6 to 6.6 ± 1.7 cm(2) and from 20.1 ± 4.8 to 6 ± 1.5 cm(2) with the NVR and RVR techniques, respectively; P < .001). In contrast to RVR, patients who underwent NVR maintained dynamic changes in mitral annular area, circumference, and anterior-posterior diameter during the cardiac cycle. Mitral leaflet mobility was reduced with both techniques, but posterior leaflet mobility was restricted with RVR. CONCLUSIONS: The size of the mitral annulus is reduced after repair with either surgical approach. Compared with resectional valve repair, more dynamic changes in the structure of the mitral annulus are maintained during the cardiac cycle with the NVR technique early postoperatively, along with more preserved motion of the posterior leaflet.

Comparative accuracy of two- and three-dimensional transthoracic and transesophageal echocardiography in identifying mitral valve pathology in patients undergoing mitral valve repair: initial observations.

BACKGROUND: Identification of mitral regurgitation (MR) mechanism and pathology are crucial for surgical repair. The aim of the present investigation was to evaluate the comparative accuracy of real-time three-dimensional (3D) transesophageal echocardiography (TEE) and transthoracic echocardiography (TTE) with two-dimensional (2D) TEE and TTE in diagnosing the mechanism of MR compared with the surgical standard. METHODS: Forty patients referred for surgical mitral valve repair were studied; 2D and 3D echocardiography with both TTE and TEE were performed preoperatively. Two independent observers reviewed the studies for MR pathology, functional or organic. In organic disease, the presence and localization of leaflet prolapse and/or flail were noted. Surgical findings served as the gold standard. RESULTS: There was 100% agreement in identifying functional versus organic MR among all four modalities. Overall, 2D TTE, 2D TEE, and 3D TEE performed similarly in identifying a prolapse or a flail leaflet; 3D TEE had the best agreement in identifying anterior leaflet prolapse, and it also showed an advantage for segmental analysis. Three-dimensional TTE was less sensitive and less accurate in identifying flail segments. CONCLUSION: All modalities were equally reliable in identifying functional MR. Both 2D TEE and 3D TEE were comparable in diagnosing MR mechanism, while 3D TEE had the advantage of better localizing the disease. With current technology, 3D TTE was the least reliable in identifying valve pathology.

Advanced Cardiovascular Sonographer: a proposal of the American Society of Echocardiography Advanced Practice Sonographer Task Force.

Echocardiographic examinations require a well-trained and competent sonographer to obtain proper anatomic and physiologic data to establish an accurate diagnosis for clinical decision-making and patient management. Although the formal education and training of cardiovascular sonographers are evolving, many entry-level and staff sonographers may not have sufficient practical or clinical knowledge of the necessary components of the echocardiographic study for the individual patient's clinical presentation. In many clinical settings, echocardiograms are read after the patient has left the laboratory. Thus, there is a role for a sonographer who can practice at an advanced level in a cardiovascular ultrasound laboratory to ensure a proper echocardiographic examination is performed on every patient. In this setting, an Advanced Cardiovascular Sonographer (ACS) would be able to review the indication for and quality of the examination. If additional images were needed, the ACS would assist the sonographer in obtaining these images, which would lead to the performance of a complete and fully diagnostic examination before the patient had left the echocardiography laboratory. In clinical practice, the quality of the examinations performed would improve, advancements in echocardiographic methods could be taught and incorporated into daily practice, and patients would be better served. The present report is a proposal from the American Society of Echocardiography Advanced Practice Task Force that identifies the potential of cardiac sonographers to achieve the ACS level.

Imaging methodology and protocols for three-dimensional echocardiography.

PURPOSE OF REVIEW: Three-dimensional echocardiography (3DE) is an additional ultrasound modality that is poised to become an integral part of the routine echocardiogram. Incorporating 3DE into clinical daily practice continues to be a challenge for many laboratories. The following review will focus on workflow processes related to methodology and protocols in order to incorporate 3DE into clinical practice. RECENT FINDINGS: Several studies have shown the clinical utility and feasibility of both transthoracic and transesophageal 3DE. In addition, many centers performing 3DE studies utilize a focused 3DE protocol as opposed to a full 3DE protocol. A majority of the studies noted limitations with respect to artifacts inherent in gated imaging and preferred real-time 3DE or rather volume imaging. A recurrent message from several recent publications is that the ultimate success and widespread clinical application of 3DE will rely mainly on improved 3D image resolution and volume rates. SUMMARY: Continuous technology improvements have led to real-time full-volume 3D imaging that is no longer prone to the artifact issues encountered with gated 3D imaging. Additional improvements to 3DE image quality and time-saving automatic quantitative analysis tools will continue to define the emerging role for routine 3DE.

Lack of pathologic Q waves: a specific marker of viability in myocardial hibernation.

BACKGROUND: The present study evaluates the lack of Q waves on the electrocardiogram (ECG) in the prediction of myocardial viability compared with dobutamine stress echocardiography (DSE) and rest-redistribution thallium-201 (Tl-201) scintigraphy. HYPOTHESIS: The lack of pathologic Q waves (NoQ) may be a readily available and specific marker for the presence of viability. METHODS: Sixty four patients with stable coronary artery disease (CAD) and ventricular dysfunction underwent rest ECG, DSE, and Tl-201 scintigraphy before revascularization, and a repeat rest 2-Dimensional (2-D) echocardiogram more than 3 mo later. RESULTS: Total viability at baseline (% of total segments) was higher in the NoQ group by Tl-201 scintigraphy (87 +/- 19% versus 70 +/- 20%, p = 0.008) and by DSE (81 +/- 20% versus 65 +/- 24%, p = 0.013). As expected, the sensitivity of NoQ waves was low in predicting recovery of function (23%), and inferior to Tl-201 (82%) and DSE (84%) (p<0.08). However, specificity of NoQ waves for predicting recovery of global function was high (72%); higher than Tl-201 (50%) and DSE (45%). Positive predictive values were comparable among all modalities. Results were similar if the data were analyzed regionally for viability. CONCLUSION: Lack of pathologic Q waves is a specific and readily available marker of myocardial viability in patients with chronic CAD, which should alert the clinician for myocardial hibernation.

Evaluation of global and regional right ventricular systolic function in patients with pulmonary hypertension using a novel speckle tracking method.

This study sought to demonstrate that a novel speckle-tracking method can be used to assess right ventricular (RV) global and regional systolic function. Fifty-eight patients with pulmonary arterial hypertension (11 men; mean age 53 +/- 14 years) and 19 age-matched controls were studied. Echocardiographic images in apical planes were analyzed by conventional manual tracing for volumes and ejection fractions and by novel software (Axius Velocity Vector Imaging). Myocardial velocity, strain rate, and strain were determined at the basal, mid, and apical segments of the RV free wall and ventricular septum by Velocity Vector Imaging. RV volumes and ejection fractions obtained with manual tracing correlated strongly with the same indexes obtained by the Velocity Vector Imaging method in all subjects (r = 0.95 to 0.98, p < 0.001 for all). Peak systolic myocardial velocities, strain rate, and strain were significantly impaired in patients with pulmonary arterial hypertension compared with controls and were most altered in patients with the most severe pulmonary arterial hypertension (p < 0.05 for all). Pulmonary artery systolic pressure and a Doppler index of pulmonary vascular resistance were independent predictors of RV strain (r = -0.61 and r = -0.65, respectively, p < 0.05 for both). In conclusion, the new automated Velocity Vector Imaging method provides simultaneous quantitation of global and regional RV function that is angle independent and can be applied retrospectively to already stored digital images.