Pedro Azcárate

Impact of collagen type I turnover on the long-term response to cardiac resynchronization therapy

AIMS We investigated whether collagen type I turnover influences the long-term response to cardiac resynchronization therapy (CRT). METHODS AND RESULTS Serum carboxy-terminal propeptide of procollagen type I or PICP (a marker of collagen type I synthesis) and carboxy-terminal telopeptide of collagen type I or CITP (a marker of collagen type I degradation) were measured in heart failure patients at baseline and after 1 year of CRT. Patients were categorized as responders or non-responders if they increased the distance walked in 6 min by > or <10%, respectively. At baseline, the PICP:CITP ratio, an index of the degree of coupling between collagen type I synthesis and degradation was higher (P = 0.006) in responders than in non-responders. Whereas the PICP:CITP ratio decreased (P= 0.000) after treatment in responders, it remained unchanged in non-responders. Thus, at 1-year, the PICP:CITP ratio was similar in the two groups of patients. A direct correlation (r = 0.289, P = 0.037) was found between the baseline PICP:CITP ratio and the change in the distance walked in 6 min in all patients. Receiver operating characteristics curves showed that a cut-off value of 14.4 for the PICP:CITP ratio provided 70% specificity and 63% sensitivity for the predicting response to CRT with a relative risk of 2.07 (95% confidence interval, 0.98-4.39). CONCLUSION Collagen type I turnover influences the long-term response to CRT. In addition, the ability of CRT to restore the balance between collagen type I synthesis and degradation is associated with a beneficial response.

Dual-source CT coronary angiogram in heart transplant recipients in comparison with dobutamine stress echocardiography for detection of cardiac allograft vasculopathy.

Conventional coronary angiography (CCA) is the gold standard in the diagnosis of cardiac allograft vasculopathy (CAV) in heart transplant recipients. Dobutamine stress echocardiography (DSE) is a useful technique for screening. Dual-source computed tomography (DSCT) is the last generation of computed tomography scanners, which could be useful to noninvasively assess CAV. Thirty cardiac transplant recipients underwent DSE and DSCT coronary angiogram. Exclusion criteria were as follows: renal insufficiency, iodinated contrast media allergy, less than 12 months since transplant, and unstable clinical conditions. DSE showed ischemia in two patients. At DSCT scan 13 patients had a normal angiogram, 13 ones wall thickening and four significant diseases. DSCT showed a sensitivity of 100% with a specificity of 92%. DSCT allowed detection of more patients with CAV than DSE. Four patients showed significant CAV at DSCT compared with two at DSE. Thirteen patients showed initial signs of disease at DSCT despite a normal DSE.

Effect of the left ventricular pacing site on echocardiographic parameters of ventricular dyssynchrony in patients receiving cardiac resynchronization therapy

INTRODUCTION AND OBJECTIVES Cardiac resynchronization therapy has been shown to be an option in the treatment of patients with congestive heart failure. The current indication for this treatment is based on clinical and electrocardiographic criteria, although echocardiography has also been shown to be a useful tool for the diagnosis of ventricular dyssynchrony. The aim of this study was to assess left ventricular dyssynchrony by echocardiography and to evaluate the effect of the stimulation site on the magnitude of resynchronization. PATIENTS AND METHOD We studied 25 patients with biventricular stimulation (left ventricular lead located in a lateral position in 13 patients, and in an anterior position in 12). A complete echo-Doppler evaluation, including left ventricular ejection fraction, ventricular diameters and parameters of inter- and intraventricular dyssynchrony, was performed before implantation and 3 months after the procedure, with the device connected and disconnected. RESULTS Left ventricular ejection fraction increased significantly from 23.7 (6.5) to 27.8 (5.5) (P=.007) at 3 months. In the group as a whole, biventricular pacing was associated with a significant decrease in all intraventricular dyssynchrony parameters (septal-to-lateral wall motion delay and septal-to-posterior wall motion delay). This decrease in septal-to-posterior wall motion delay and septal-to-lateral wall motion delay was significantly greater in patients with the electrode implanted in the lateral position (58.1 ms vs 118 ms; P=.02) than with the lead in the anterior position (39.5 ms vs 86.5 ms; P=.04). Three patients, all with the electrode in an anterior location, were considered non-responders. CONCLUSIONS Left lateral free wall stimulation provided significantly better intraventricular resynchronization compared to stimulation at an anterior site. Echocardiography is a useful tool to evaluate changes in intra- and interventricular synchrony related to the pacing site.

Obstructive Sleep Apnea Severity Is Associated with Left Ventricular Mass Independent of Other Cardiovascular Risk Factors in Morbid Obesity

OBJECTIVE To evaluate the relation between obstructive sleep apnea (OSA) and left ventricular mass (LVM) in morbid obesity and the influence of gender, menopausal status, anthropometry, body composition, hypertension, and other cardiovascular risk factors in this relationship. DESIGN Cross-sectional descriptive study. METHODS Polysomnographic and echocardiographic studies were performed in a cohort of 242 patients (86 men, 100 premenopausal (PreM) and 56 postmenopausal (PostM) women), with grade II obesity and above (BMI: 43.7 ± 0.4 kg/m(2)) to investigate OSA and LVM respectively. Anthropometry, body composition, glucose tolerance, and blood pressure were also recorded. RESULTS OSA to different degrees was diagnosed in 76.2% of the patients (n: 166), its prevalence being 90.9% (n: 70) for men, and 76% (n: 38) and 63.8% (n: 58) for PostM and PreM women, respectively (p < 0.01). LVM excess was greatest for PostM women (90.2%), followed by men (81.9%) and PreM females (69.6%) (p < 0.01). LVM values increased in accordance to OSA severity (absence, 193.7 ± 6.9 g; mild, 192.6 ± 7.8 g; moderate, 240.5 ± 12.5 g; severe, 273.6 ± 14.6 g; p < 0.01). LVM magnitude correlated with the menopausal state, age, central adiposity, hypertension (HT), type 2 diabetes (DM), desaturation index (DI), and apnea-hypopnea index (AHI) (r = 0.41; p < 0.01). The relationship between LVM and AHI persisted in the multivariate analysis (β = 0.25; p < 0.05) after adjusting for age, gender, menopausal state, BMI, waist circumference, neck circumference, DI, fasting plasma glucose, DM, and HT. But if tobacco habits are included, the statistical difference disappears (β = 0.22; p = 0.06). CONCLUSIONS Morbid obesity is frequently associated with abnormal LVM, particularly in patients with OSA; this association is independent of HT, BMI, body composition, and other clinical factors, supporting a direct role of OSA on LVM in morbid obesity. This suggests that OSA and LVM might be taken as predictors of the cardiovascular risk in these patients.

Assessment of left ventricular parameters in orthotopic heart transplant recipients using dual-source CT and contrast-enhanced echocardiography: Comparison with MRI

OBJECTIVES To establish the accuracy and reliability of cardiac dual-source CT (DSCT) and two-dimensional contrast-enhanced echocardiography (CE-Echo) in estimating left ventricular (LV) parameters with respect to cardiac magnetic resonance imaging (CMR) as the reference standard. METHODS Twenty-five consecutive heart transplant recipients (20 male, mean age 62.7±10.4 years, mean time since transplantation 8.1±5.9 years) were prospectively recruited. Two blinded readers independently assessed LV ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), and stroke volume (SV) for each patient after manual tracing of the endo- and epicardial contours in DSCT, CE-Echo and CMR cine images. Students t-test for paired samples for differences, and Bland and Altman plots and Lins concordance-correlation coefficients (CCC) for agreement were calculated. RESULTS There was no statistical difference between left ventricular parameters determined by DSCT and CMR. CE-Echo resulted in significant underestimation of left ventricular volumes (mean difference EDV: 15.94±14.19 ml and 17.1±17.06 ml, ESV: 8.5±9.3 and 7.32±9.14 ml with respect to DSCT and CMR), and overestimation of EF compared with the cross-sectional imaging modalities (3.78±8.47% and 2.14±8.35% with respect to DSCT and CMR). Concordance correlation coefficients for LV parameters using DSCT and CMR were higher (CCC≥0.75) than CCC values observed between CE-Echo and DSCT- or CMR-derived data (CCC≥0.54 and CCC≥0.49, respectively). Interobserver agreement was higher for DSCT and CMR values (CCC≥0.72 and CCC≥0.87, respectively). CONCLUSION In orthotopic heart transplantation cardiac DSCT allows accurate and reliable estimation of LV parameters compared with CMR, whereas CE-Echo seems to be insufficient to obtain precise measurements.

Allograft morphology and function in heart transplant recipients surviving more than 15 years by magnetic resonance imaging and dual-source computed tomography.

OBJECTIVE Cardiac allograft vasculopathy and late graft failure are the main limiting factors of long-term success of heart transplantation, and little is known about graft function in the long-term survivors. The aim of this study was to assess the ventricular function and the allograft vasculopathy in long-term survivors (>15 years) with the cardiac magnetic resonance imaging (MRI) and dual-source computed tomography (DSCT) coronary angiogram. METHODS In our database, 34 cardiac recipients have more than 15 years of follow-up and were evaluated for this study; 22 (65%) of them were enrolled. Mean age at transplant was 46 ± 13.5 years, mean donor age was 28.5 ± 10.1 years, and mean graft ischemic time was 189 ± 58 min. Mean follow-up was 18.5 ± 2.4 years (range 15-22). All patients underwent cardiac MRI and DSCT. RESULTS Mean left ventricular (LV) volumes indexed to the body surface area (BSA) were within normal range: the end-diastolic volume/BSA was 61 ± 16 ml m(-2), end-systolic volume/BSA was 22 ± 15 ml m(-2), stroke volume/BSA was 38 ± 6 ml m(-2), LV mass/BSA: 72 ± 18 g m(-2), and mean ejection fraction (EF) was 0.59 ± 0.08. Two patients (9%) showed a global cardiac hypokinesia and two other patients (9%) showed akinesia of one segment. At DSCT, 41% of patients had a strictly normal coronary angiogram, 41% had wall thickening and 18% presented a least one >60% stenosis. CONCLUSIONS Cardiac MRI and DSCT coronary angiogram revealed a normal graft function and morphology after more than 15 years of transplantation. However, a certain number of patients have significant cardiac allograft vasculopathy and another consistent group has initial disease. These patients deserve further follow-up and tailoring of the immunosuppressive regimen.

Fases de reconstrucción y exactitud de la tomografía computarizada para cuantificar la función y masa ventricular izquierda

PURPOSE To compare the accuracy of cardiac dual-source CT (DSCT) reconstructions obtained at 5% and 10% of the cardiac cycle and MRI for quantifying global left ventricular (LV) function and mass in heart transplant recipients. MATERIAL AND METHODS We prospectively included 23 heart transplant recipients (21 male, mean age 60±11.7 years) who underwent cardiac DSCT and MRI examinations. We compared LV parameters on cardiac DSCT reconstructions obtained at 5% (0%-95%) and 10% (0%-90%) intervals of the cardiac cycle and on double-oblique short-axis MR images. We determined ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), and myocardial mass using commercially available semiautomated segmentation analysis software for DSCT datasets and conventional manual contour tracing for MR studies. RESULTS Using different reconstruction intervals to quantify LV parameters at DSCT resulted in non-significant differences (P>.05). Compared to MRI, DSCT slightly overestimated LV-EDV, ESV, and mass when both 5% (11.5±25.1ml, 6.8±10.9ml, and 28.3±21.6g, respectively) and 10% (mean difference 15.3±26.3ml, 7.4±11.5ml, and 29.3±18.7g, respectively) reconstruction intervals were used. DSCT and MRI estimates of EF and SV were not significantly different. CONCLUSION In heart transplant recipients, DSCT allows reliable quantification of LV function and mass compared with MRI, even using 10% interval reconstructions.

Miocarditis aguda: diagnóstico mediante resonancia magnética cardiaca

Cardiomyopathies are a common cause of morbidity and mortality. Myocarditis, which is included among specific cardiomyopathies, frequently presents non-specific clinical manifestations and thus may be difficult to diagnose, or even be misdiagnosed. Traditionally employed diagnostic techniques, including endomyocardial biopsy, have been shown to be of limited value. Following its overall implantation in clinical practice, cardiac magnetic resonance imaging (MRI) is nowadays widely considered to be the best non-invasive diagnostic tool available for diagnosing myocarditis.

Tratamiento de la insuficiencia cardíaca avanzada mediante estimulación biventricular. Experiencia inicial en una serie de 22 casos consecutivosBiventricular Pacing as a Treatment for Advanced Heart Failure. Preliminary Experience in a Series of 22 Consecutive Patients

Background and objectives. Recent data suggest that biventricular pacing may play an important role in treating advanced heart failure in the presence of a significant interventricular and/or intraventricular conduction disorder by correcting cardiac dysynchrony. In this article, we review the initial technical and clinical experience with cardiac resynchronization therapy in an electrophysiology laboratory. Methods. The first 22 consecutive patients with severe congestive heart failure, ejection fraction 120 ms who were implanted biventricular pacemakers were studied. Clinical, electrocardiographic, and echocardiographic evaluations were made before and three months after pacemaker implantation. Acute functional capacity testing with peak oxygen uptake was measured during biventricular pacing and during intrinsic rhythm or right ventricular pacing three months after the implantation procedure. Results. The success rate of pacemaker implantation was 95%. Pre-discharge left ventricular pacing was achieved in 91%, with an average pacing threshold of 1.53 (1.04) volts. NYHA functional class improved (p = 0.039) from 3.4 (0.7) to 2.3 (0.78). The rate of hospitalization for heart failure decreased from an average of 3.12 (0.58) three months before the procedure to 1.38 (0.34) three months after the procedure. Peak oxygen uptake was significantly greater (p = 0.028) during biventricular pacing: 14.89 (2.1) ml/min/kg, than during intrinsic rhythm or right ventricular pacing: 12.65 (2.3) ml/min/kg. Conclusions. Cardiac resynchronization therapy can be performed safely and with a high success rate in the electrophysiology laboratory. Biventricular pacing seems to improve the symptoms of congestive heart failure in patients with evidence of atrioventricular and/or interventricular/intraventricular dysynchrony. An acute benefit in H EART F AILUREBACKGROUND AND OBJECTIVES Recent data suggest that biventricular pacing may play an important role in treating advanced heart failure in the presence of a significant interventricular and/or intraventricular conduction disorder by correcting cardiac dysynchrony. In this article, we review the initial technical and clinical experience with cardiac resynchronization therapy in an electrophysiology laboratory. METHODS The first 22 consecutive patients with severe congestive heart failure, ejection fraction < 0.35, NYHA functional class III or IV, and QRS duration > 120 ms who were implanted biventricular pacemakers were studied. Clinical, electrocardiographic, and echocardiographic evaluations were made before and three months after pacemaker implantation. Acute functional capacity testing with peak oxygen uptake was measured during biventricular pacing and during intrinsic rhythm or right ventricular pacing three months after the implantation procedure. RESULTS The success rate of pacemaker implantation was 95%. Pre-discharge left ventricular pacing was achieved in 91%, with an average pacing threshold of 1.53 (1.04) volts. NYHA functional class improved (p = 0.039) from 3.4 (0.7) to 2.3 (0.78). The rate of hospitalization for heart failure decreased from an average of 3.12 (0.58) three months before the procedure to 1.38 (0.34) three months after the procedure. Peak oxygen uptake was significantly greater (p = 0.028) during biventricular pacing: 14.89 (2.1) ml/min/kg, than during intrinsic rhythm or right ventricular pacing: 12.65 (2.3) ml/min/kg. CONCLUSIONS Cardiac resynchronization therapy can be performed safely and with a high success rate in the electrophysiology laboratory. Biventricular pacing seems to improve the symptoms of congestive heart failure in patients with evidence of atrioventricular and/or interventricular/intraventricular dysynchrony. An acute benefit in peak oxygen uptake was associated with biventricular pacing after the implantation procedure.