Diab Mutlak

Functional Tricuspid Regurgitation in Patients With Pulmonary Hypertension: Is Pulmonary Artery Pressure the Only Determinant of Regurgitation Severity?

BACKGROUND Pulmonary hypertension is a common cause of functional tricuspid regurgitation (TR), but other factors play a role in determining TR severity. The objectives of our study were to determine the distribution of TR severity in relation to pulmonary artery systolic pressure (PASP) and to define the determinants of TR severity. METHODS The echocardiographic reports and selected echocardiographic studies of patients with echocardiographic estimation of PASP were reviewed. Patients with organic tricuspid valve (TV) disease were excluded from the analysis. RESULTS Among 2,139 patients, the frequency of moderate or severe TR was progressively greater in patients with higher PASP. Nevertheless, TR was only mild in a substantial proportion of patients with high PASP (mild TR in 65.4% of patients with PASP 50-69 mm Hg and in 45.6% of patients with PASP >or= 70 mm Hg). By multivariate analysis, age, female gender, PASP (odds ratio, 2.26 per 10-mm Hg increase; 95% confidence interval, 1.95 to 2.61), pacemaker lead, right atrial (RA) and right ventricular enlargement, left atrial enlargement, and organic mitral valve disease were independently associated with greater degrees of TR. In patients with PASP >or= 70 mm Hg, RA size, tricuspid annular diameter, and TV tethering area were greater in patients with greater degrees of TR. CONCLUSIONS PASP is a strong determinant of TR severity, but many patients with pulmonary hypertension do not exhibit significant TR. In addition to PASP, demographic characteristics, mechanical factors, remodeling of the right heart cavities, and other factors (possibly reflecting the presence of atrial fibrillation or occult organic TV disease) are predictive of TR severity.

Relation of Myocardial Mechanics in Severe Aortic Stenosis to Left Ventricular Ejection Fraction and Response to Aortic Valve Replacement

Decreased left ventricular (LV) longitudinal strain and increased circumferential LV strain have been demonstrated in patients with severe aortic stenosis (AS) and normal LV ejection fraction (LVEF). Biplane myocardial mechanics normalize after aortic valve replacement (AVR). This study objective was to examine LV mechanics before and soon after AVR in patients with AS and LV systolic dysfunction. Paired echocardiographic studies before and soon (7 ± 3 days) after AVR were analyzed in 64 patients with severe AS: 32 with normal LVEF (≥ 50%), 16 with mild to moderate LV dysfunction (LVEF <36% to 50%), and 16 with severe LV dysfunction (LVEF ≤ 35%). Longitudinal myocardial function was assessed from 3 apical views (average of 18 segments) and circumferential function was assessed at mid-LV and apical levels (average of 6 segments per view). Strain, strain rate, and mid-LV and apical rotations were measured using 2-dimensional velocity vector imaging. Before AVR (1) longitudinal strain was low in all patients and correlated with LVEF (ρ = 0.74, p <0.001), (2) mid-LV circumferential strain was supranormal in patients with normal LVEF and low in patients with low LVEF (ρ = 0.88, p <0.001), and (3) apical rotation was highest in patients with mild to moderate LV dysfunction. After AVR, LVEF increased in patients with LV dysfunction and myocardial mechanics partly normalized. In conclusion, compensatory mechanisms (high circumferential strain in patients with preserved LVEF and increased apical rotation in patients with mild to moderate LV dysfunction) were observed in patients with severe AS. Compensatory mechanics were lost in patients with severe LV dysfunction. AVR partly reversed these changes in patients with LV dysfunction.

Differential effects of afterload on left ventricular long- and short-axis function: insights from a clinical model of patients with aortic valve stenosis undergoing aortic valve replacement.

BACKGROUND The effects of left ventricular (LV) afterload on longitudinal versus circumferential ventricular mechanics are largely unknown. Our objective was to examine changes in LV deformation before and early after aortic valve replacement (AVR) in patients with severe aortic valve stenosis (AS). METHODS Paired echocardiographic studies before and early (7 +/- 3 days) after AVR were analyzed in 45 patients (age 67 +/- 12 years, 49% men) with severe AS and normal LV ejection fraction without segmental wall motion abnormalities. Longitudinal myocardial function was assessed from 3 apical views (average of 18 segments). Circumferential function was assessed at mid and apical levels (averaging 6 segments per view). Strain, strain rate (SR), and LV twist (relative rotation of the mid and apex) were measured using 2-dimensional strain software. RESULTS Early post-AVR, (1) LV size and LV ejection fraction did not change; (2) longitudinal systolic strain, which was lower than normal before AVR, increased (-12.8 +/- 1.7 to -15.9 +/- 2.2, P < .05), whereas mid-LV circumferential strain, which was higher than normal, decreased (-27.0 +/- 5.1 to -22.3 +/- 4.9, P < .05); (3) longitudinal early diastolic SR increased (0.6 +/- 0.1 to 0.7 +/- 0.2, P < .05), whereas mid-LV circumferential diastolic SR decreased (1.2 +/- 0.5 to 1.0 +/- 0.3, P < .05); and (4) LV twist increased (3.7 degrees +/- 2.1 degrees to 6.1 degrees +/- 2.9 degrees , P < .05). CONCLUSIONS Aortic valve stenosis causes differential changes in longitudinal and circumferential mechanics that partially normalize after AVR. These findings provide new insights into the mechanical adaptation of the LV to chronic afterload elevation and its response to unloading.

Velocity Vector Imaging: standard tissue-tracking results acquired in normals--the VVI-STRAIN study.

BACKGROUND Echocardiographic imaging assessment of left ventricular mechanics is a new technology that is offered by various vendors. Different software algorithms have at times yielded conflicting results. The aim of this study was to determine normal myocardial mechanical parameters in a healthy population using Velocity Vector Imaging. METHODS One hundred twenty subjects were selected for this study, including healthy subjects referred for echocardiography to evaluate minor symptoms or murmurs, who had normal echocardiographic findings and healthy volunteers. Study subjects were recruited in Haifa, Israel and Toronto, Canada. Echocardiography was performed using commercially available systems to analyze archived studies. Endocardial and epicardial longitudinal and circumferential strain and strain rate were calculated as well as rotational mechanical parameters. Age and gender differences were evaluated. RESULTS Average endocardial longitudinal, circumferential, and radial strains and twist were -19.6 ± 2.0%, -27.6 ± 3.9%, +30.1 ± 7.5%, and 9.6 ± 3.9°, respectively. Epicardial circumferential strain and twist were -11.3 ± 2.2% and 4.0 ± 1.9°, respectively. Shortening increased from base to apex longitudinally (10%) and circumferentially (33%). Thickening at the apex was 16% lower than at the base. Men and older subjects had increased endocardial circumferential strain and apical rotation. CONCLUSIONS Mechanical parameters differ with location (endocardial vs epicardial, basal vs apical strain gradients), age, and gender. Care should be taken when comparing regional strain measurements between systems, and gender and age should be matched between and within two-dimensional strain systems.

Pulmonary Hypertension, Right Ventricular Function, and Clinical Outcome in Acute Decompensated Heart Failure

BACKGROUND Pulmonary hypertension (PH) and right ventricular (RV) dysfunction have been associated with adverse outcome in patients with chronic heart failure. However, data are lacking in the setting of acute decompensated heart failure (ADHF). We sought to determine prognostic significance of PH in patients with ADHF and its interaction with RV function. METHODS We studied 326 patients with ADHF. Pulmonary artery systolic pressure (PASP) and RV function were determined with the use of Doppler echocardiography, with PH defined as PASP >50 mm Hg. The primary end point was all-cause mortality during 1-year follow-up. RESULTS PH was present in 139 patients (42.6%) and RV dysfunction in 83 (25.5%). The majority of patients (70%) with RV dysfunction had PH. Compared with patients with normal RV function and without PH, the adjusted hazard ratio (HR) for mortality was 2.41 (95% confidence interval [CI] 1.44-4.03; P = .001) in patients with both RV dysfunction and PH. Patients with normal RV function and PH had an intermediate risk (adjusted HR 1.78, 95% CI 1.11-2.86; P = .016). Notably, patients with RV dysfunction without PH were not at increased risk for 1-year mortality (HR 1.04, 95% CI 0.43-2.41; P = .94). PH and RV function data resulted in a net reclassification improvement of 22.25% (95% CI 7.2%-37.8%; P = .004). CONCLUSIONS PH and RV function provide incremental prognostic information in ADHF. The combination of PH and RV dysfunction is particularly ominous. Thus, the estimation of PASP may be warranted in the standard assessment of ADHF.

Frequency, Determinants and Outcome of Pulmonary Hypertension in Patients With Aortic Valve Stenosis

Introduction:The frequency, causes and prognostic implications of pulmonary hypertension (PHT) in patients with severe aortic stenosis (AS) are not well defined. The objectives of this study were to determine the frequency of PHT [pulmonary artery systolic pressure (PASP) >50 mm Hg] in patients with severe AS, identify the factors associated with PHT and assess the relationship between PHT and clinical outcome. Methods:Patients with severe AS (aortic valve area ⩽1.0 cm2) and an echocardiographic estimate of PASP were identified by using the institutional echocardiography laboratory database. Patients with atrial fibrillation, mitral valve stenosis or a mitral prosthesis were excluded from analysis. The associations between clinical and echocardiographic parameters and PHT and the relationship between PHT and outcome were examined. Results:During the study period, 216 patients fulfilled the inclusion criteria (age: 75 ± 11 years; 43% men), and PHT was present in 64 patients (29.6%). By multivariate analysis, reduced left ventricular (LV) systolic function (LV ejection fraction ⩽45% and lower stroke volume) and impaired LV diastolic function (mitral inflow E/A ratio ≥1.5 and greater left atrium size) were independent predictors of PHT. Mortality was higher among patients with PHT managed medically (adjusted hazard ratio, 1.87; 95% confidence interval, 1.06–3.30; P = 0.011), whereas patients with PHT who underwent aortic valve replacement had an excellent outcome. Conclusions:PHT is common in patients with AS and is related to the severity of LV systolic and diastolic dysfunction. PHT is associated with poorer outcome in medically treated patients.

Restrictive Left Ventricular Filling Pattern and Risk of New-Onset Atrial Fibrillation After Acute Myocardial Infarction

Mechanisms for atrial arrhythmias that occur in the context of acute myocardial infarction (AMI) have not been well characterized. AMI often leads to alterations in left ventricular (LV) filling dynamics, which may result in advanced diastolic dysfunction. Diastolic dysfunction may produce increased left atrial (LA) pressure and initiate LA remodeling, promoting the progression to atrial fibrillation (AF). We studied 1,169 patients admitted with AMI. Advanced diastolic dysfunction was defined as a restrictive filling pattern (RFP), defined as ratio of early to late transmitral velocity of mitral inflow >1.5 or deceleration time <130 ms. The relation between RFP and the primary end point of new-onset AF occurring within 6 months was analyzed using multivariable Cox models. Of 1,169 patients (70% men, mean ± SD 64 ± 10 years of age), 110 (9.4%) developed new-onset AF (19.6% and 7.5% in patients with and without RFP, respectively, p <0.0001). RFP was associated with a hazard ratio of 2.72 for AF (95% confidence interval 1.83 to 4.05, p <0.0001). After multivariable adjustments for clinical variables, LV ejection fraction (EF) and LA size, RFP remained an independent predictor of AF (hazard ratio 2.17, 95% confidence interval 1.42 to 3.32, p <0.0001). Risk of AF was higher in patients with RFP for preserved (≥45%, hazard ratio 2.14, 95% confidence interval 1.09 to 4.20, p = 0.03) or decreased (hazard ratio 2.80, 95% confidence interval 1.63 to 4.82, p <0.0001) LVEF. In contrast, decreased LVEF in the absence of RFP was similar to that of patients with preserved LVEF and without RFP. In conclusion, in patients with AMI, presence of advanced diastolic dysfunction was independently associated with new-onset AF, suggesting that increased filling pressures may contribute to the development of AF after AMI.

Impact of Diastolic Dysfunction on the Development of Heart Failure in Diabetic Patients After Acute Myocardial Infarction

Background—Diabetes is often associated with an abnormal diastolic function. However, there are no data regarding the contribution of diastolic dysfunction to the development of heart failure (HF) in diabetic patients after acute myocardial infarction. Methods and Results—A total of 1513 patients with acute myocardial infarction (417 diabetic) underwent echocardiographic examination during the index hospitalization. Severe diastolic dysfunction was defined as a restrictive filling pattern (RFP) based on E/A ratio >1.5 or deceleration time <130 ms. The primary end points of the study were readmission for HF and all-cause mortality. The frequency of RFP was higher in patients with diabetes (20 versus 14%; P=0.005). During a median follow-up of 17 months (range, 8 to 39 months), 52 (12.5%) and 62 (5.7%) HF events occurred in patients with and without diabetes, respectively (P<0.001). There was a significant interaction between diabetes and RFP (P=0.04) such that HF events among diabetic patients occurred mainly in those with RFP. The adjusted hazard ratio for HF was 2.77 (95%, CI 1.41 to 5.46) in diabetic patients with RFP and 1.21 (95% CI, 0.75 to 1.55) in diabetic patients without RFP. A borderline interaction (P=0.059) was present with regard to mortality (adjusted hazard ratio, 3.39 [95% CI, 1.57 to 7.34] versus 1.61 [95% CI, 1.04 to 2.51] in diabetic patients with and without RFP, respectively). Conclusion—Severe diastolic dysfunction is more common among diabetic patients after acute myocardial infarction and portends adverse outcome. HF and mortality in diabetic patients occur predominantly in those with concomitant RFP.

Diagnostic accuracy of myocardial hypoenhancement on multidetector computed tomography in identifying myocardial infarction in patients admitted with acute chest pain syndrome.

Objective: To evaluate prevalence and diagnostic accuracy of myocardial hypoenhancement (MH) using multidetector computed tomography (MDCT) in patients admitted for acute chest pain syndromes. Methods: Sixty-nine patients underwent first-pass MDCT, coronary angiography, and echocardiography. Using a standardized analysis protocol, left ventricular short-axis reformations were evaluated for presence, size, and density of MH in 16 myocardial segments. These were correlated with the presence and location of myocardial infarction (MI), regional myocardial dysfunction, and coronary artery disease. Results: Myocardial hypoenhancement was found in acute MI (27/35), healed MI (6/14), unstable angina (3/9), and atypical chest pain (0/11). Sensitivity, specificity, and positive and negative predictive values of MH for diagnosing any MI were 67%, 85%, 92% and 52%, respectively. Conclusions: The presence of MH on MDCT in acute chest pain patients has high positive predictive value and specificity but only moderate sensitivity for presence of acute or healed MI using the strict criteria proposed in this study.

Relationship of functional mitral regurgitation to new-onset atrial fibrillation in acute myocardial infarction

Background/objective The role of factors that increase left atrial pressure or cause acute left atrial dilatation is frequently emphasised in the pathogenesis of atrial fibrillation (AF) in patients with acute myocardial infarction (AMI). This study was designed to test the hypothesis that functional mitral regurgitation (FMR) occurring after AMI may promote AF by producing left atrial volume overload. Setting Intensive care unit of a tertiary care hospital. Patients and Methods 1920 patients admitted with AMI were studied. Patients with known AF were excluded. FMR was classified using echocardiography into three groups: none; mild FMR and moderate or severe FMR. The relationship between FMR and AF occurring at any time during the hospital course was examined using multivariable logistic regression. Results Mild FMR was present in 744 patients (38.8%) and moderate or severe FMR was present in 150 patients (7.8%). AF developed in 51 (5.0%), 83 (11.2%) and 28 (18.7%) patients with no FMR, mild FMR and moderate or severe FMR, respectively (p trend <0.001). In multivariable logistic regression, both mild (odds ratio (OR) 1.6; 95% CI 1.1 to 2.3, p=0.02) and moderate or severe FMR (OR 2.1; 95% CI 1.2 to 3.6, p=0.007) were independent predictors of AF. There was a significant interaction between the left ventricular ejection fraction and FMR (p=0.003) such that mild FMR was predictive of AF only in patients with a reduced (<45%) ejection fraction. Conclusions There is a graded independent association between the severity of FMR and the new onset of AF in patients with AMI.