Jaroslav Meluzín

Prognostic value of the amount of dysfunctional but viable myocardium in revascularized patients with coronary artery disease and left ventricular dysfunction

OBJECTIVES The purpose of our study was to assess the prognostic importance of the amount of dysfunctional but viable myocardium in revascularized patients with coronary artery disease (CAD) and left ventricular (LV) dysfunction. BACKGROUND The amount of dysfunctional but viable myocardium predicts the functional improvement after revascularization and may offer more precise risk stratification of patients referred for bypass surgery or coronary angioplasty. METHODS Two hundred and seventy-four consecutive patients with CAD and LV ejection fraction < or =40% underwent low-dose dobutamine echocardiography for viability assessment. One hundred and thirty-three of them were revascularized using either coronary artery bypass surgery (118 patients) or coronary angioplasty (15 patients) and entered this study. To quantify the amount of dysfunctional but viable myocardium, wall motion was scored using 16-segment model. The dysfunctional segments were defined as viable if they exhibited improvement in their thickening by at least 1 grade with dobutamine infusion. The patients were followed up for a mean period of 20+/-12 months (range, 2 to 48) for cardiac mortality and nonfatal cardiac events including myocardial infarction, unstable angina pectoris requiring hospitalization and hospitalization for heart failure. Standard follow-up echocardiography was performed 3 to 6 months after revascularization. RESULTS Twenty-nine patients exhibited a large amount of dysfunctional but viable myocardium (> or =6 segments, group A), 60 patients had a small amount of dysfunctional but viable myocardium (2 to 5 segments, group B) and 44 patients were found to have dysfunctional myocardium irreversibly damaged (group C). Similar prerevascularization LV ejection fractions of 35%+/-5%, 34%+/-4%, 36%+/-4% in groups A, B and C increased to 47%+/-6% (p < 0.01 vs. baseline, p < 0.01 vs. groups B and C), to 40%+/-5% (p < 0.01 vs. baseline) and to 37%+/-6% (p = NS vs baseline), respectively, after revascularization. The greatest functional improvement after revascularization in group A patients was accompanied by a lower rate of cardiac events during follow-up (2 vs. 18 in group B, p < 0.05, and vs. 17 in group C, p < 0.01) and better cardiac event-free survival according to Kaplan-Meier survival analysis (p < 0.05 vs. groups B and C, respectively). CONCLUSION In revascularized patients with CAD and moderate or severe LV dysfunction, the presence of a large amount of dysfunctional but viable myocardium identifies patients with the best prognosis.

Prognostic Importance of the Right Ventricular Function Assessed by Doppler Tissue Imaging

AIMS We sought to assess whether the peak systolic and diastolic tricuspid annular velocities as indicators of the right ventricular systolic and diastolic function are of prognostic importance in patients with symptomatic heart failure. METHODS AND RESULTS The study included 139 consecutive patients with symptomatic heart failure. Their mean left ventricular ejection fraction was 24% (range, 10-39%); 107 patients (77%) were in functional class III according to the New York Heart Association. All patients underwent clinical and laboratory examination, standard echocardiography completed by the Doppler tissue imaging of the tricuspid annular motion, and the right-sided heart catheterization. They were followed up for cardiac-related death and non-fatal cardiac events including the need for implantation of a cardioverter-defibrillator and hospitalization for heart failure. The median follow-up was 11 months (range, 1-48 months). There were 17 cardiac-related deaths and 23 non-fatal cardiac events. The multivariate stepwise Cox regression modelling revealed three effective predictors for both survival and event-free survival: aetiology of heart failure, left ventricular end-diastolic diameter, and the peak systolic tricuspid annular velocity (Sa). Patients with Sa<10.8cms(-1) exhibited worse survival (P=0.048) and event-free survival (P<0.001) compared with those having Sa>/=10.8cms(-1). Risk values of Sa (<10.8cms(-1)) and the left ventricular end-diastolic diameter (>70mm) were found to be of additive simultaneous influence leading to a very poor prognosis, mainly if aetiology of heart failure was idiopathic dilated cardiomyopathy (P<0.001). CONCLUSION The Sa represents a significant independent predictor of survival and event-free survival in patients with symptomatic heart failure. Its combination with the left ventricular end-diastolic diameter provides a very powerful tool for patient risk stratification.

A Fast and Simple Echocardiographic Method of Determination of the Optimal Atrioventricular Delay in Patients After Biventricular Stimulation

The optimization of atrioventricular (AV) delay is known to signifcantly contribute to maximum cardiac performance. The aim of this study was to validate a new, fast, and simple echocardiographic method of identifying the AV delay that provides the maximum cardiac output (CO). Right heart catheterization and Doppler echocardiography of transmitral filling were performed simultaneously in 18 patients with heart failure and at least minimum functional mitral regurgitation treated with atrial synchronized biventricular pacing. CO derived from catheterization and Doppler filling parameters were measured at the predicted optimal AV delay (oAVD), the short AV delay (oAVD − 50 ms), and the long AV delay (oAVD + 28 ms on average/range, +10 ms to +50 ms) during a constant heart rate. The AV delay was regarded as optimal if the end of atrial contraction (represented by the end of A wave of transmitral filling) coincided with the beginning of ventricular contraction (heralded by the onset of the systolic component of mitral regurgitation). Prediction of the optimal AV delay included the following steps: (1) The maximum AV delay at which full ventricular capture is still preserved was found under electrocardiographic control. (2) This value, decreased by 5 to 10 ms, was designated as “the testing long AV delay,” and the time interval from the end of the A wave to the onset of the systolic component of mitral regurgitation (time t1) was measured at this setting. (3) oAVD was simply calculated as “the testing long AV delay”− time t1. The CO measured at the oAVD (4.5 ± 0.7 1 · min−1) significantly exceeded those at the short AV delay (4.3 ± 0.7 1 · min−1, P < 0.01) and the long AV delay (4.4 ± 0.8 1 · min−1, P < 0.01), respectively. The method correctly determined the maximum CO in 78% of the patients. In conclusion, Doppler echocardiography enables very rapid and accurate optimization of AV synchrony in patients after the implantation of a biventricular pacemaker. (PACE 2004; 27:58–64)

Left Ventricular Mechanics in Idiopathic Dilated Cardiomyopathy: Systolic-Diastolic Coupling and Torsion

BACKGROUND In idiopathic dilated cardiomyopathy (IDC), myocardial deformational parameters and their mutual relationships remain incompletely characterized. METHODS Thirty-seven patients with IDC underwent two-dimensional speckle-tracking echocardiography (2D-STE) to assess left ventricular rotation, torsion, and longitudinal, circumferential, and radial systolic and diastolic strains and strain rates. Additionally, 2D-STE was performed in 14 controls. RESULTS All deformational parameters on 2D-STE were significantly lower in patients with IDC compared with controls. Seven patients exhibited opposite basal (positive, counterclockwise) and 11 patients exhibited opposite apical (negative, clockwise) rotation at end-systole. Circumferential, radial, and longitudinal early diastolic strain rates were correlated most strongly with the corresponding spatial components of systolic deformation. CONCLUSION In patients IDC, all torsional, systolic, and diastolic deformational parameters were decreased. Corresponding three-dimensional components of systolic and diastolic deformations were closely coupled. Considerable variation in the direction of basal and apical rotation exists in a subset of patients with IDC.

Short-term Effects of Cardiac Resynchronization Therapy on Sleep-Disordered Breathing in Patients With Systolic Heart Failure

OBJECTIVES We evaluated the short-term effect of cardiac resynchronization therapy (CRT) on sleep apnea in patients with systolic heart failure. BACKGROUND Sleep-disordered breathing is common in patients with left ventricular systolic dysfunction. METHODS Twelve patients (mean [+/-SE] age, 59.6+/-7.8 years; mean left ventricular ejection fraction, 28.0+/-2.8%) with an implanted atrial-synchronized biventricular pacemaker for the treatment of left ventricular systolic dysfunction were selected and studied. Each subject underwent polysomnography on 3 consecutive nights with CRT on the first night, CRT off the second night, and CRT on the third night. Echocardiography was performed prior to each polysomnogram. RESULTS The central sleep event index (ie, the number of central sleep apneas [CSAs] and hypopneas per hour of sleep) score was lower with CRT compared to that without CRT (mean central sleep event index score with CRT on, 6.9+/-1.7 events per hour of sleep; mean central sleep event index score with CRT off, 14.3+/-2.9 events per hour of sleep; mean central sleep event index score with CRT on, 8.1+/-1.5 events per hour of sleep; p<0.001). Similarly, the cumulative duration of central sleep events (the number of minutes per hour of sleep during CRT) was one half that observed without CRT (CRT on, 2.8+/-0.7 min per hour of sleep; CRT OFF 6.2+/-1.2 min per hour of sleep; CRT ON 3.1+/-0.7 min per hour of sleep; p<0.001). There was a significant correlation between mitral regurgitant volume and central sleep event index on all three nights (r>or=0.77; p<0.01). CONCLUSIONS CRT reduces CSA severity in the short term. This reduction correlated significantly with the CRT-mediated reduction of mitral regurgitation.

Right ventricular dysfunction in chronic heart failure patients

To evaluate any differences in haemodynamic and echocardiographic parameters in patients with both left (LV) and right ventricular (RV) systolic dysfunction and in patients with isolated LV systolic dysfunction.

Estimation of left ventricular filling pressures by speckle tracking echocardiography in patients with idiopathic dilated cardiomyopathy

AIMS the ratio of early diastolic transmitral flow velocity (E) to early diastolic mitral annular velocity (E(a)) is frequently used to predict an increase in left ventricular filling pressure (LVFP). However, this approach has several limitations. The aim of this study was to test whether additional information is gained by new echocardiographic indexes utilizing strain and strain rate (SR) derived from 2-dimensional speckle tracking echocardiography (2D-STE) for the estimation of LVFP. METHODS AND RESULTS fifty-one patients with idiopathic dilated cardiomyopathy (IDC) underwent pulsed-wave tissue Doppler echocardiography and 2D-STE performed simultaneously with right heart catheterization. Receiver operating characteristic analysis showed that circumferential strain and the SR during late diastolic LV filling (0.956 and 0.951, both P = 0.001), E/circumferential SR at early diastolic LV filling (0.949, P = 0.001), and E/circumferential strain at the time of peak E-wave (0.948, P = 0.001) had greater area under the curve than the E/E(a) ratio (0.911, P = 0.001) for the prediction of pulmonary capillary wedge pressure > 12 mmHg. CONCLUSION when compared with the E/E(a) ratio, several 2D-STE-derived parameters better estimated the increase in LVFP in patients with IDC.

Prognosis of patients with chronic coronary artery disease and severe left ventricular dysfunction. The importance of myocardial viability

The choice of optimal treatment strategy in patients with coronary artery disease (CAD) and severe left ventricular (LV) dysfunction is often difficult. The aim of this study was to compare long‐term results of patients with chronic CAD, severe heart failure and a defined scope of myocardial viability treated with coronary revascularization, heart transplantation, or kept on medical therapy.

Association of coronary artery disease, erectile dysfunction,and endothelial nitric oxide synthase polymorphisms

The purpose of this study was to determine the relationship between erectile dysfunction (ED), coronary artery disease (CAD), and T−786C and intron 4 a/b endothelial nitric oxide synthase (eNOS) polymorphisms in 419 patients with suspected or known CAD referred for coronary angiography. The patients had a high prevalence of risk factors for both CAD and ED: hypercholesterolemia (64%), hypertension (74%), diabetes mellitus (25%), obesity (30%), and smoking (63%). Three hundred and twenty-one patients had significant coronary atherosclerosis (luminal diameter narrowing of 50% or more of at least 1 coronary artery), 41 had insignificant coronary stenoses, and 57 patients were found to have coronary arteries without the evidence of atherosclerosis. The prevalence of ED in these groups was 79%, 76%, and 67% (P = NS), respectively. As compared to patients without ED, those with ED exhibited significantly higher probability of having significant coronary atherosclerosis (69% vs 79%, P = 0.04), higher number of significant coronary stenoses (median, 1 vs 2, P = 0.004), and a higher prevalence of a triple-vessel disease (12% vs 25%, P = 0.004). We did not find any relationship between T−786C and intron 4 a/b polymorphisms and the manifestation of coronary atherosclerosis or the presence of ED. In conclusion, in patients with numerous cardiovascular risk factors referred for coronary angiography, there was a high prevalence of ED in patients with both the presence and the absence of coronary atherosclerosis. The coincidence of CAD and ED identified patients at increased risk of severe forms of CAD.

The role of exercise echocardiography in the diagnostics of heart failure with normal left ventricular ejection fraction

AIMS Few data are available on the exercise-induced abnormalities of myocardial function in patients with exertional dyspnoea and normal left ventricular ejection fraction (LV EF). The main aims of this study were to determine the prevalence of isolated exercise-induced heart failure with normal ejection fraction (HFNEF) and to assess whether disturbances in LV or right ventricular longitudinal systolic function are associated with the diagnosis of HFNEF. METHODS AND RESULTS Eighty-four patients with exertional dyspnoea and normal LV EF and 14 healthy controls underwent spirometry, NT-proBNP plasma analysis, and exercise echocardiography. Doppler LV inflow and tissue mitral and tricuspid annular velocities were analysed at rest and immediately after the termination of exercise. Of the 30 patients with the evidence of HFNEF, 6 (20%) patients had only isolated exercise-induced HFNEF. When compared with the remaining patients, those with HFNEF had a significantly lower resting and exercise peak mitral annular systolic velocity (Sa) and the mitral annular velocity during atrial contraction, lower exercise peak mitral annular velocity at early diastole, and lower exercise peak systolic velocity of tricuspid annular motion. The multivariate logistic regression analysis including both parameters standardly defining HFNEF and the new Doppler variables potentially associated with the diagnosis of HFNEF revealed that NT-proBNP, LV mass index, left atrial volume index, and Sa significantly and independently predict the diagnosis of HFNEF. CONCLUSION A significant proportion of patients require exercise to diagnose HFNEF. Sa appears to be a significant independent predictor of HFNEF, which may increase the diagnostic value of models utilizing the variables recommended by the European Society of Cardiology guidelines.