Jasmine Grewal

Mitral Annular Dynamics in Myxomatous Valve Disease New Insights With Real-Time 3-Dimensional Echocardiography

Background— Mitral annulus is a complex structure of poorly understood physiology. Full-volume real-time 3-dimensional transesophageal echocardiography offers a unique opportunity to completely image and quantify mitral annulus size and motion. Methods and Results— Real-time 3-dimensional transesophageal echocardiography of the mitral valve was acquired in 32 patients with myxomatous valve disease (MVD) and moderate to severe regurgitation, 15 normal control subjects, and 10 patients with ischemic mitral regurgitation of identical body surface area. Mitral annular dimensions (circumference, area, anteroposterior and intercommissural diameters, height, and ratio of height to intercommissural diameter ratio, which appraises annular saddle-shape depth) were measured throughout the cardiac cycle with dedicated quantification software. Compared with direct surgical measurement, 3-dimensional anterior annular dimension provided reliable measurements (mean difference, 0.1±0.1 mm; P=0.73; 95% confidence interval, ±4.4 mm). Annular dimensions were larger in MVD patients compared with control subjects in diastole (all P<0.05). Normal annulus displayed early-systolic anteroposterior (P<0.001) and area (P=0.04) contraction, increased height (P<0.001), and deeper saddle shape (ratio of height to intercommissural diameter, 15±1% to 21±1%; P<0.001), whereas intercommissural diameter was unchanged (P=0.30). In contrast, MVD showed early-systolic intercommissural dilatation (P=0.02) and no area contraction (P=0.99), height increase (P=0.11), or saddle-shape deepening (P=0.35). Late-systolic MVD annular saddle shape deepened but annular area excessively enlarged (P<0.04) as a result of persistent intercommissural widening (P<0.02). MVD annulus also contrasts with ischemic mitral regurgitation annulus, which, despite similar anteroposterior enlargement, is narrower and essentially adynamic. After MVD repair, the annulus remained dynamic without systolic saddle-shape accentuation (P=0.30). Conclusions— Real-time 3-dimensional transesophageal echocardiography provides insights into normal, dynamic mitral annulus function with early-systolic area contraction and saddle-shape deepening contributing to mitral competency. MVD annulus is also dynamic but considerably different with loss of early-systolic area contraction and saddle-shape deepening despite similar magnitude of ventricular contraction, suggestive of ventricular-annular decoupling. Subsequent area enlargement may contribute to mitral incompetence. After mitral repair, MVD annulus remains dynamic without systolic saddle-shape accentuation. Thus, real-time 3-dimensional transesophageal echocardiography provides new insights that allow the refining of mitral pathophysiology concepts and repair strategies.

Real-Time Three-Dimensional Transesophageal Echocardiography in the Intraoperative Assessment of Mitral Valve Disease

BACKGROUND The aims of this study were to evaluate the feasibility of real-time 3-dimensional (3D) transesophageal echocardiography in the intraoperative assessment of mitral valve (MV) pathology and to compare this novel technique with 2-dimensional (2D) transesophageal echocardiography. METHODS Forty-two consecutive patients undergoing MV repair for mitral regurgitation (MR) were studied prospectively. Intraoperative 2D and 3D transesophageal echocardiographic (TEE) examinations were performed using a recently introduced TEE probe that provides real-time 3D imaging. Expert echocardiographers blinded to 2D TEE findings assessed the etiology of MR on 3D transesophageal echocardiography. Similarly, experts blinded to 3D TEE findings assessed 2D TEE findings. Both were compared with the anatomic findings reported by the surgeon. RESULTS At the time of surgical inspection, ischemic MR was identified in 12% of patients, complex bileaflet myxomatous disease in 31%, and specific scallop disease in 55%. Three-dimensional TEE image acquisition was performed in a short period of time (60 +/- 18 seconds) and was feasible in all patients, with optimal (36%) or good (33%) imaging quality in the majority of cases. Three-dimensional TEE imaging was superior to 2D TEE imaging in the diagnosis of P1, A2, A3, and bileaflet disease (P < .05). CONCLUSIONS Real-time 3D transesophageal echocardiography is a feasible method for identifying specific MV pathology in the setting of complex disease and can be expeditiously used in the intraoperative evaluation of patients undergoing MV repair.

Three-Dimensional Echocardiographic Assessment of Right Ventricular Volume and Function in Adult Patients With Congenital Heart Disease: Comparison With Magnetic Resonance Imaging

BACKGROUND The aim of this study was to evaluate the accuracy of three-dimensional (3D) ultrasound compared with the standard magnetic resonance imaging method in determining right ventricular (RV) volumes and function in adult patients with congenital heart disease and chronic, severe pulmonary regurgitation (PR). METHODS Twenty-five patients with severe PR secondary to either pulmonary valvotomy or tetralogy of Fallot repair were evaluated using 3D ultrasound and MRI. RESULTS The mean RV ejection fractions were 42 +/- 8% on 3D ultrasound and 44 +/- 7% on MRI (r = 0.89, P < .0001). The mean end-diastolic volumes were 249 +/- 66 and 274 +/- 82 mL and the mean end-systolic volumes 147 +/- 50 and 159 +/- 60 mL on 3D ultrasound and MRI, respectively. Similarly, there were strong correlations of both end-diastolic volume and end-systolic volume on 3D ultrasound and MRI (r = 0.88 and r = 0.89, respectively). CONCLUSIONS Three-dimensional ultrasound was comparable with MRI in determining RV size and function in most patients with complex congenital heart disease. It will be important to study 3D US in a larger population of patients with TOF, which will be possible only through multi-center collaboration.

BNP and NT-proBNP predict echocardiographic severity of diastolic dysfunction.

To evaluate the best combination of clinical parameters and brain natriuretic peptide (BNP) or N‐terminal pro‐BNP (NT‐proBNP), to predict diastolic dysfunction (DD) in heart failure with preserved left ventricular ejection fraction (HF‐PLEF) as determined by Doppler‐echocardiography.

Usefulness of N-Terminal Pro–Brain Natriuretic Peptide and Brain Natriuretic Peptide to Predict Cardiovascular Outcomes in Patients With Heart Failure and Preserved Left Ventricular Ejection Fraction

More than 40% of patients hospitalized with heart failure have preserved left ventricular ejection fraction (HF-PLVEF) and are at high risk for cardiovascular (CV) events. The purpose of this study was to determine the value of N-terminal pro-brain natriuretic peptide (NT-proBNP) and brain natriuretic peptide (BNP) in predicting CV outcomes in patients with HF-PLVEF. Participants with an ejection fraction >40% in the prospective CHARM Echocardiographic Substudy were included in this analysis. Plasma NT-proBNP levels were measured, and 2 cut-offs were selected prospectively at 300 pg/ml and 600 pg/ml. BNP cut-off was set at 100 pg/ml. Clinical characteristics were recorded, and systolic and diastolic function were evaluated by echocardiography. The primary substudy outcome was the composite of CV mortality, hospitalization for heart failure, and myocardial infarction or stroke. A total of 181 patients were included, and there were 17 primary CV events (9.4%) during a median follow-up time of 524 days. In a model including clinical characteristics, echocardiographic measures, and BNP or NT-proBNP, the composite CV event outcome was best predicted by NT-proBNP >300 pg/ml (hazard ratio 5.8, 95% confidence intervals [CI] 1.3 to 26.4, p = 0.02) and moderate or severe diastolic dysfunction on echocardiography. When NT-proBNP >600 pg/ml was used in the model, it was the sole independent predictor of primary CV events (hazard ratio 8.0, 95% CI 2.6 to 24.8, p = 0.0003) as was BNP >100 pg/ml (hazard ratio 3.1, 95% CI 1.2 to 8.2, p = 0.02) in the BNP model. In conclusion, both elevated NT-proBNP and BNP are strong independent predictors of clinical events in patients with HF-PLVEF.

Pregnancy Outcomes in Women With Dilated Cardiomyopathy

OBJECTIVES The objectives of this study were to determine adverse outcomes during pregnancy in women with dilated cardiomyopathy (DCM) and to compare their cardiac outcomes with those of nonpregnant women with DCM. BACKGROUND Women with DCM are at risk for complications during pregnancy, but few studies have examined outcomes in this specific population. METHODS This was a substudy of a larger prospective cohort study of outcomes in women with heart disease. Maternal cardiac, obstetric, and fetal outcomes in pregnancy in women with DCM were examined. For comparison, cardiac outcomes in nonpregnant women with DCM (n = 18) matched by age and left ventricular (LV) systolic function were examined. A matched-pair survival analysis was used to compare groups. RESULTS Thirty-six pregnancies in 32 women with DCM were included. Thirty-nine percent (14 of 36) of the pregnancies were complicated by at least 1 maternal cardiac event. In the multivariate analysis, moderate or severe LV dysfunction and/or New York Heart Association functional class III or IV (p = 0.003) were the main determinants of adverse maternal cardiac outcomes during pregnancy. In the subset of women with moderate/severe LV dysfunction, 16-month event-free survival was worse in pregnant women compared with nonpregnant women (28 +/- 11% vs. 83 +/- 10%, p = 0.02). The adverse neonatal event rate was highest among women with obstetric and cardiac risk factors (43%). CONCLUSIONS In pregnant women with DCM the risk of adverse cardiac events is considerable, and pre-pregnancy characteristics can identify women at the highest risk. Pregnancy seems to have a short-term negative impact on the clinical course in women with DCM.

Cardiac outcomes after pregnancy in women with congenital heart disease

Objective Women with congenital heart disease (CHD) are at risk for adverse cardiac events during pregnancy; however, the risk of events late after pregnancy (late cardiac events; LCE) has not been well studied. A study was undertaken to examine the frequency and determinants of LCE in a large cohort of women with CHD. Design Baseline characteristics and pregnancy were prospectively recorded. LCE (>6 months after delivery) were determined by chart review. Survival analysis was used to determine the risk factors for LCE. Setting A tertiary care referral hospital. Patients The outcomes of 405 pregnancies were studied (318 women; median follow-up 2.6 years). Main outcome measures LCE included cardiac death/arrest, pulmonary oedema, arrhythmia or stroke. Results LCE occurred after 12% (50/405) of pregnancies. The 5-year rate of LCE was higher in women with adverse cardiac events during pregnancy than in those without (27±9% vs 15±3%, HR 2.2, p=0.02). Women at highest risk for LCE were those with functional limitations/cyanosis (HR 3.9, 95% CI 1.2 to 13.0), subaortic ventricular dysfunction (HR 3.0, 95% CI 1.4 to 6.6), subpulmonary ventricular dysfunction and/or significant pulmonary regurgitation (HR 3.2, 95% CI 1.6 to 6.6), left heart obstruction (HR 2.6, 95% CI 1.2 to 5.2) and cardiac events before or during pregnancy (HR 2.6, 95% CI 1.3 to 4.9). In women with 0, 1 or >1 risk predictors the 5-year rate of LCE was 7±2%, 23±5% and 44±10%, respectively (p<0.001). Conclusions In women with CHD, pre-pregnancy maternal characteristics can help to identify women at increased risk for LCE. Adverse cardiac events during pregnancy are important and are associated with an increased risk of LCE.

Is the Anterior Intertrigonal Distance Increased in Patients With Mitral Regurgitation Due to Leaflet Prolapse

BACKGROUND Severe mitral regurgitation (MR) leads to progressive enlargement of left ventricular dimensions and, consequently, the mitral valve (MV) annulus. Data from animal and cadaver studies suggest that the mitral annulus may dilate asymmetrically in certain conditions, which may influence the choice of valve repair technique. Although it is generally accepted that the posterior mitral annulus dilates in patients with severe MR due to leaflet prolapse, the stability of the anterior intertrigonal distance has not yet been demonstrated in humans. METHODS We obtained real-time, three-dimensional (3D) transesophageal echocardiographic images of the MV in 44 patients: 29 patients scheduled to undergo MV repair for severe MR due to leaflet prolapse (MV disease group) and 15 normal outpatients undergoing evaluation for various reasons (control group). Mitral valve repair was performed by median sternotomy or minimally invasively using thoracoscopic or robotic assistance. All patients underwent implantation of a standard-length flexible 63-mm posterior annuloplasty band at the time of mitral repair and we obtained postoperative 3D images for 11 patients after separation from bypass. Mitral annular dimensions were measured throughout the cardiac cycle using reconstructive analysis software (QLAB MVQ Version 6.0; Phillips, Bothell, WA). RESULTS The mean patient age was 60 years; 30 were men. The mean ejection fraction was 0.61 and was similar between the two groups (p = 0.16). In patients with MR due to leaflet prolapse, posterior annular length and total annular circumference were significantly larger than in control patients (p < 0.001). In contrast, there was no detectable difference in the anterior intertrigonal distance between patients with MR and normal controls. After mitral valve leaflet repair and posterior annuloplasty there was a significant decrease in both the total annular circumference and posterior annular length (p < 0.0001) while cyclic annular contraction was preserved. CONCLUSIONS Although the posterior mitral annulus is enlarged in patients with significant MR due to degenerative leaflet prolapse, there is no evidence that the intertrigonal distance is abnormal in these patients. Our data support the conclusion that posterior annular reduction with a flexible device at the time of mitral valve repair is important, and that altering the anterior intertrigonal portion of the mitral annulus is unnecessary.

Size, shape, and stamina: the impact of left ventricular geometry on exercise capacity.

Although several studies have examined the cardiac functional determinants of exercise capacity, few have investigated the effects of structural remodeling. The current study evaluated the association between cardiac geometry and exercise capacity. Subjects with ejection fraction ≥50% and no valvular disease, myocardial ischemia, or arrhythmias were identified from a large prospective exercise echocardiography database. Left ventricular mass index and relative wall thickness were used to classify geometry into normal, concentric remodeling, eccentric hypertrophy, and concentric hypertrophy. All of the subjects underwent symptom-limited treadmill exercise according to standard Bruce protocol. Maximal exercise tolerance was measured in metabolic equivalents. Of 366 (60±14 years; 57% male) subjects, 166 (45%) had normal geometry, 106 (29%) had concentric remodeling, 40 (11%) had eccentric hypertrophy, and 54 (15%) had concentric hypertrophy. Geometry was related to exercise capacity: in descending order, the maximum achieved metabolic equivalents were 9.9±2.8 in normal, 8.9±2.6 in concentric remodeling, 8.6±3.1 in eccentric hypertrophy, and 8.0±2.7 in concentric hypertrophy (all P<0.02 versus normal). Left ventricular mass index and relative wall thickness were negatively correlated with exercise tolerance in metabolic equivalents (r=−0.14; P=0.009 and r=−0.21; P<0.001, respectively). Augmentation of heart rate and ejection fraction with exercise were blunted in concentric hypertrophy compared with normal, even after adjusting for medications. In conclusion, the pattern of ventricular remodeling is related to exercise capacity among low-risk adults. Subjects with concentric hypertrophy display the greatest limitation, and this is related to reduced systolic and chronotropic reserve. Reverse remodeling strategies may prevent or treat functional decline in patients with structural heart disease.

Drug therapies in the secondary prevention of cardiovascular diseases: Successes, shortcomings and future directions.

Cardiovascular diseases are the major cause of death and a significant cause of disability in the Western world and more recently threaten to pose an increasing health burden on developing nations. People with pre-existent vascular disease are those at highest risk for adverse cardiovascular outcomes and require aggressive secondary preventive therapies. Large strides have been made in the development of pharmacologic agents that intervene on various pathways implicated in atherogenesis, thus offering the ability to greatly impact on disease progression and to prevent events. Compelling data derived primarily from randomized controlled trials have shown the benefits of aspirin (or antiplatelet agents) and angiotensin converting enzyme (ACE) inhibitors (A), beta-blockers and blood pressure (B) and cholesterol-lowering drugs (C), particularly statins, in preventing recurrent events and improving survival. Taken together these data are the foundation for the simple, but important advice for secondary prevention - the ABCs. In addition, the evidence for the central role of lifestyle factors as determinants of risk has lead to increased efforts towards developing interventions aimed at modifying lifestyle patterns. Today, the biggest challenge remains in the implementation of proven effective therapies. Our focus should turn to educating physicians and patients alike regarding available therapies and their indications. In addition systematic, sustainable and globally applicable approaches to the secondary prevention of cardiovascular diseases need to be developed to truly realize the vast potential benefits of existing therapies.