Integración de la imagen mecánica,estructural y eléctrica para entender la respuesta a la terapia de resincronización cardiaca

Introduction and objectives

There is extensive controversy exists on whether cardiac resynchronization therapy corrects electrical or mechanical asynchrony. The aim of this study was to determine if there is a correlation between electrical and mechanical sequences and if myocardial scar has any relevant impact.

Methods

Six patients with normal left ventricular function and 12 patients with left ventricular dysfunction and left bundle branch block, treated with cardiac resynchronization therapy, were studied. Real-time three-dimensional echocardiography and electroanatomical mapping were performed in all patients and, where applicable, before and after therapy. Magnetic resonance was performed for evaluation of myocardial scar. Images were postprocessed and mechanical and electrical activation sequences were defined and time differences between the first and last ventricular segment to be activated were determined. Response to therapy was defined as a reduction in left ventricular end-systolic volume ≥ 15% after 12 months of follow-up.

Results

Good correlation between electrical and mechanical timings was found in patients with normal left ventricular function (r² = 0.88; P = .005) but not in those with left ventricular dysfunction (r² = 0.02; P = not significant). After therapy, both timings and sequences were modified and improved, except in those with myocardial scar.

Conclusions

Despite a close electromechanical relationship in normal left ventricular function, there is no significant correlation in patients with dysfunction. Although resynchronization therapy improves this correlation, the changes in electrical activation may not yield similar changes in left ventricular mechanics particularly depending on the underlying myocardial substrate.Full English text available from: www.revespcardiol.org\en     

Etiological diagnosis of left ventricular dysfunction: computed tomography compared with coronary angiography and cardiac magnetic resonance

Introduction and objectives

To evaluate the capability of multidetector computed tomography to diagnose the coronary etiology of left ventricular dysfunction compared with using invasive coronary angiography and magnetic resonance.

Methods

Forty consecutive patients with left ventricular dysfunction of uncertain etiology underwent invasive coronary angiography and contrast magnetic resonance. All patients were evaluated with multidetector computed tomography including coronary calcium presence and score, noninvasive coronary angiography, and myocardial tissue assessment.

Results

The sensitivity and specificity of the presence of coronary calcium to identify left ventricular dysfunction was 100% and 31%, respectively. If an Agatston calcium score of >100 is taken, specificity increases to 58% with sensitivity still 100%. Sensitivity and specificity for coronary angiography by multidetector computed tomography was 100% and 96%, respectively; for identifying necrosis in contrast acquisition it was 57% and 100%, respectively; and in late acquisition, 84% and 96%, respectively. To identify coronary ventricular dysfunction with necrosis, the sensitivity and specificity was 92% and 100%, respectively.

Conclusions

Of all the diagnostic tools available in multidetector computed tomography, coronary angiography is the most accurate in determining the coronary origin of left ventricular dysfunction. A combination of coronary angiography and myocardial tissue study after contrast allows a single test to obtain similar information compared with the combination of invasive coronary angiography and contrast magnetic resonance.Full English text available from:www.revespcardiol.org     

Pérdida de estimulación biventricular continua en pacientes con terapia de resincronización cardiaca: incidencia,causas y resultados

Introduction and objectives

In recent years, implantation of cardiac resynchronization therapy devices has significantly increased. The benefits of this therapy are directly related to the maintenance of continuous biventricular pacing. This study analyzed the incidence, causes, and outcomes of loss of continuous biventricular pacing, and the approach adopted.

Methods

We analyzed the clinical and follow-up data of a series of consecutive patients from a single center who underwent implantation of a cardiac resynchronization therapy device.

Results

The study included 136 patients. During a mean follow-up of 33.4 months, loss of continuous biventricular pacing occurred in 45 patients (33%). The most common causes included atrial tachyarrhythmias (21.3%), lead macrodislodgement (18%), and loss of left ventricular capture (13.1%). In most patients (88.5%), loss of continuous biventricular pacing was transient and correctable, and occurred earlier in the follow-up when the cause was lead macrodislodgement, oversensing, or extracardiac stimulation. There were no significant differences in mortality between patients with and without loss of continuous biventricular pacing (P=.88).

Conclusions

Despite technical advances in cardiac resynchronization therapy, loss of continuous biventricular pacing is common; however, this loss can usually be corrected. In most patients, continuous biventricular pacing can be ensured by close monitoring and follow-up and a proactive approach.Full English text available from:www.revespcardiol.org/en     

Structural and Functional Inverse Cardiac Remodeling After Cavotricuspid Isthmus Ablation in Patients With Typical Atrial Flutter

Introduction and objectives

The purpose of the present study is to determine the structural and functional cardiac changes that occur in patients at 1-year follow-up after ablation of typical atrial flutter.

Methods

We enrolled 95 consecutive patients referred for cavotricuspid isthmus ablation. Echocardiography was performed at ≤6 h post-procedure and 1-year follow-up.

Results

Of 95 patients initially included, 89 completed 1-year follow-up. Hypertensive cardiopathy was the most frequently associated condition (39%); 24% of patients presented low baseline left ventricular systolic dysfunction. We observed a significant reduction in right and left atrial areas, end-diastolic and end-systolic left ventricular diameters, and interventricular septum. We observed substantial improvement in right atrium contraction fraction and left ventricular ejection fraction, and a reduction in pulmonary hypertension. Changes in diastolic dysfunction pattern were observed: 60% of patients progressed from baseline grade III to grade I; at 1-year follow-up, this improvement was found in 81%. We found no structural differences between paroxysmal and persistent atrial flutter at baseline and 1-year follow-up, exception for basal diastolic function.

Conclusions

In patients with typical atrial flutter undergoing cavotricuspid isthmus catheter ablation, we found inverse structural and functional cardiac remodeling at 1-year follow-up with much improved left ventricular ejection fraction, right atrium contraction fraction, and diastolic dysfunction pattern.     

Análisis transversal de la resincronización cardiaca en España. Indicaciones,técnicas de implante,optimización y seguimiento

Introduction and objectives

A cross-sectional study of cardiac resynchronization therapy use in Spain was performed to analyze problems with indications, implantation, and patient follow-up.

Methods

Spanish cardiac resynchronization therapy implanter centers were identified, then the department members were surveyed and the data were recorded by each implantation team.

Results

Eighty-eight implanter centers were identified; of these, 85 (96.6%) answered the survey. A total of 2147 device implantations were reported, comprising 85.6% of the overall number of 2518 implantations estimated by the European Confederation of Medical Suppliers Associations for the same period. The reported implantation rate was 46 per million inhabitants versus an estimated implantation rate of 51 per million (European average, 131). Cardiac resynchronization therapy devices accounted for 84% of implantations, and upgrades to previously implanted devices, 16%. The majority of cardiac resynchronization therapy devices were implanted in men (70.7%). The mean age was 68 (12) years, and the mean left ventricular ejection fraction was 26.4% (5%). Most patients (67%) were in New York Heart Association functional class III. The group of patients for whom cardiac resynchronization therapy was indicated according to the latest update of the guidelines was significant: 17.3% among New York Heart Association class II patients and more than 21.6% among patients with atrial fibrillation. In all, electrophysiologists accounted for 73.8% of implanters, followed by surgeons, accounting for 21.4%.

Conclusions

The latest update of the guidelines is being progressively implemented in Spain, according to data obtained in patients in New York Heart Association class II or with atrial fibrillation. Nevertheless, the number of cardiac resynchronization therapy device implants is still well below the European average.Full English text available from:www.revespcardiol.org     

Prevalence and severity of ventricular dysfunction in patients with HIV-related pulmonary arterial hypertension

Objectives

To evaluate the occurrence of ventricular systolic dysfunction in human immunodeficiency virus (HIV)-related pulmonary arterial hypertension (PAH).

Background

Patients with HIV-related PAH may develop ventricular systolic dysfunction both as a consequence of PAH progression or of the myocardial involvement from the HIV infection itself.

Methods

Cardiac magnetic resonance imaging was applied to measure ejection fraction for the left ventricle and the right ventricle in patients with HIV-related PAH (n = 27) and in patients with PAH from other aetiologies (n = 115).

Results

In HIV-related PAH, ejection fraction values were lower and a higher proportion of patients presented with an advanced stage of ventricular dysfunction (55% vs. 25%; p = 0.009). In a multivariate model, PAH related to HIV infection remained independently associated with advanced ventricular dysfunction (p = 0.011).

Conclusions

Patients with HIV-related PAH have more prevalent and severe ventricular systolic dysfunction compared to patients with PAH from other aetiologies.     

Myocardial scar characteristics based on cardiac magnetic resonance imaging is associated with ventricular tachyarrhythmia in patients with ischemic cardiomyopathy

Objectives

We hypothesized that myocardial scar characterization using cardiac magnetic resonance imaging (CMR) may be associated with the occurrence of ventricular tachyarrhythmia (VT), appropriate implantable cardioverter-defibrillator (ICD) therapy and mortality.

Background

Since a minority of patients with prophylactic ICD implantation receive appropriate ICD therapy, there is a need for more effective risk stratification for primary prevention in patients with ischemic cardiomyopathy.

Methods and results

In 99 patients with ischemic cardiomyopathy, CMR was performed prior to ICD implantation. We assessed if CMR indices (cardiac mass, LVEF) and CMR scar characteristics (infarct core mass, peri-infarction mass and the ratio's between left ventricular mass, infarct core mass and peri-infarction mass) were associated with outcome. The primary endpoint was sustained VT and/or appropriate ICD therapy. The secondary endpoint was all-cause mortality. During a median follow-up of 5.4 years (IQR 4.5–6.6 years), 34 patients reached the primary end-point (17 appropriate ICD shocks) and 26 patients died. In multivariable Cox regression analysis, peri-infarction to core-infarction ratio (HR 2.01, 95%CI: 1.17–3.44, p = 0.01) was independently and significantly associated with the primary endpoint, whereas NYHA-class and lower LVEF were not. Conversely, age (HR 1.06, 95% CI: 1.01–1.12, p = 0.02) and lower LVEF (HR 0.95, 95% CI: 0.91–1.00, p = 0.04) were independently associated with all-cause mortality, mainly due to heart failure.

Conclusion

A relatively large peri-infarction mass is associated with sustained VT and/or appropriate ICD therapy, whereas age and lower LVEF are associated with mortality. CMR based tissue characterization could aid in the prediction of specific outcome measures and in clinical decision making.     

Myocardial Atrophy and Chronic Mechanical Unloading of the Failing Human Heart : Implications for Cardiac Assist Device–Induced Myocardial Recovery

Background

In animal models of heterotopic transplantation, mechanical unloading of the normal, nonhypertrophic heart results in atrophy. Primarily on the basis of these animal data, the notion that chronic left ventricular assist device (LVAD)-induced unloading will result in atrophy has dominated the clinical heart failure field, and anti-atrophic drugs have been used to enhance the cardiac recovery potential observed in some LVAD patients. However, whether unloading-induced atrophy in experimental normal heart models applies to failing and hypertrophic myocardium in heart failure patients unloaded by continuous-flow LVADs has not been studied.

Objectives

The study examined whether mechanical unloading by continuous-flow LVAD leads to myocardial atrophy.

Methods

We prospectively examined myocardial tissue and hemodynamic and echocardiographic data from 44 LVAD patients and 18 untransplanted normal donors.

Results

Cardiomyocyte size (cross-sectional area) decreased after LVAD unloading from 1,238 ± 81 μm² to 1,011 ± 68 μm² (p = 0.001), but not beyond that of normal donor hearts (682 ± 56 μm²). Electron microscopy ultrastructural evaluation, cardiomyocyte glycogen content, and echocardiographic assessment of myocardial mass and left ventricular function also did not suggest myocardial atrophy. Consistent with these findings, t-tubule morphology, cytoplasmic penetration, and distance from the ryanodine receptor were not indicative of ongoing atrophic remodeling during LVAD unloading. Molecular analysis revealed no up-regulation of proatrophic genes and proteins of the ubiquitin proteasome system.

Conclusions

Structural, ultrastructural, microstructural, metabolic, molecular, and clinical functional data indicated that prolonged continuous-flow LVAD unloading does not induce hypertrophy regression to the point of atrophy and degeneration. These findings may be useful in designing future investigations that combine LVAD unloading and pharmaceutical therapies as a bridge to recovery of the failing heart.     

LV mechanical dispersion as a predictor of ventricular arrhythmia in patients with advanced systolic heart failure

Background

Myocardial mechanical dyssynchrony induced by the presence of postinfarction scar and/or conduction abnormalities in patients with a left ventricular ejection fraction (LVEF) of < 35 % may be associated with a greater propensity toward inducing serious ventricular arrhythmia [(ventricular tachycardia (VT), ventricular fibrillation (VF)] and sudden cardiac death. The assessment of regional myocardial function using tissue Doppler echocardiography (TDE) allows for noninvasive analysis of regional mechanical dysfunction (LV mechanical dispersion).

Aim

The aim of this study was to evaluate the TDE-based mechanical dispersion as a potential echocardiographic predictor of VT/VF.

Methods

The study group consisted of 47 consecutive ambulatory patients with implanted cardiac resynchronization therapy–defibrillator (CRT-D) devices who were divided into two groups: Group 1 (n = 29) comprised patients with recorded episodes of VT/VF, in whom baseline TDE data were available, and group 2 (n = 18) comprised patients without registered VT/VF in the device memory within 4 years after implantation. LV mechanical dispersion was defined as the standard deviation of the time measured from the beginning of the QRS complex to the peak longitudinal strain in apical four-chamber and two-chamber views. A retrospective quantitative assessment of LV regional deformation was based on the color tissue velocity recordings.

Results

The average time to event after implantation was 345 days. Patients with electrical events demonstrated greater mechanical dispersion: 99.14 ± 33.60 vs. 72.98 ± 19.70, p=0.002.

Conclusion

During the 4-year follow-up, patients with documented VT/VF were characterized by significantly higher LV mechanical dispersion as compared with patients without electrical events. Measurement of LV mechanical dispersion might be helpful in determining the risk of sudden cardiac death.

     

Midterm Effects and Clinical Benefits of Left Ventricular vs Biventricular Pacing in Heart Failure

Background

Although left ventricular pacing (LVP) leads to a greater acute hemodynamic response than does biventricular pacing (BVP), the long-term effects are diverse. We aimed to assess the efficacy of LVP and BVP in patients undergoing cardiac resynchronization therapy and determine which patients would benefit more from LVP or BVP.

Methods

Randomized controlled trials that compared left and biventricular pacing were retrieved from MEDLINE and analyzed for changes in cardiac function and dimensions, cardiac resynchronization therapy response, and electromechanical effects.

Results

A total of 811 patients were included from 9 trials. After a mean follow-up, a shorter QRS duration (−40.92 milliseconds; 95% confidence interval [CI], −64.50 to −17.34; P = 0.0007), and improved left ventricular dimensions were observed in the BVP group compared with the LVP group. Moreover, the BVP group had a longer 6-minute hall walk (6MHW) test (37.19 m; 95% CI, 4.72 to 69.67; P = 0.02).

Conclusion

Our results indicate that BVP results in a better electromechanical effect and leads to a better 6MHW test. For all other test criteria, LVP showed a benefit equal to that of BVP. Thus, there is currently insufficient evidence to advocate for LV-only pacing.     

Relationship of Electro-mechanical Remodeling to Survival Rates after Cardiac Resynchronization Therapy

Cardiac resynchronization therapy, when added to optimal medical therapy, increases longevity in symptomatic congestive heart failure patients with left ventricular ejection fractions (LVEF) ≤0.35 and QRS durations >120 ms. Cardiac resynchronization therapy is also associated with electrical and mechanical reverse remodeling. We examined whether reverse remodeling predicts increased survival rates in non-trial settings.Recipients of cardiac resynchronization therapy and defibrillators (n=112; 78 men; mean age, 69 ± 11 yr) underwent repeat echocardiography and electrocardiography at least 90 days after device implantation. Forty patients had mechanical responses of at least 0.05 improvement in absolute LVEF; 56 had electrical responses (any narrowing of biventricular-paced QRS duration compared with the electrocardiogram immediately after therapy). During a mean follow-up period of 3.1 ± 1.7 years, 55 patients died. The average death rate per 100 person-years was lower among mechanical responders than nonresponders (9.2% vs 23.9%; P=0.009); the unadjusted hazard ratio was 0.39 (95% confidence interval [CI], 0.19–0.79).In a multivariate model adjusted for age, sex, baseline LVEF, and QRS duration, mechanical responders had 60% better survival than nonresponders (hazard ratio=0.40; 95% CI, 0.21–0.79; P=0.008). No difference in survival was observed in electrical response. In our association of absolute change in LVEF over the observed range with death (using restricted cubic splines), we observed a linear relationship with survival.In patients given cardiac resynchronization therapy, mechanical but not electrical remodeling was associated with better survival rates, suggesting that mechanical remodeling underlies this therapy''s mechanism of conferring a survival benefit.Key words: Cardiac resynchronization therapy/methods, combined modality therapy, heart conduction system/physiopathology, heart failure/mortality/physiopathology/therapy, predictive value of tests, survival analysis, ventricular dysfunction, left/mortality/prevention & control/therapy, ventricular remodelingIn selected heart-failure patients, cardiac resynchronization therapy (CRT) improves exercise tolerance, maximal oxygen consumption, and quality of life, and reduces the risks of repeat hospitalization for heart failure or death.^1,2 Lower left ventricular ejection fraction (LVEF) is a predictor of cardiac events independently of QRS duration or electrical evidence of dyssynchrony.^3,4 Secondary data analyses from clinical trials yielded better clinical outcomes in the context of reverse mechanical remodeling.^5,6 In addition, electrical dyssynchrony—commonly observed in patients with left ventricular (LV) dysfunction⁷—is a predictor of LV systolic dysfunction.^8,9 Data from clinical practice are sparse in regard to associations of reverse mechanical and electrical remodeling with improved survival rates. In this study, we examined the association between electromechanical reverse remodeling and survival rates in a tertiary-care hospital.     

Five-year follow-up of left ventricular diastolic function in systemic sclerosis patients: Determinants of mortality and disease progression

Objectives

In systemic sclerosis (SSc), left ventricular diastolic dysfunction reflects primary myocardial involvement of the disease. We aimed to assess the abnormalities of the diastolic function, analyze the characteristics of the disease progression, and investigate the prognostic value of diastolic dysfunction in SSc patients.

Patients and methods

A total of 34 SSc patients (57 ± 12 years, 31 female) were involved in the study. The following traditional or tissue Doppler parameters of left ventricular diastolic function were obtained: E/A, lateral E?, E/E?, left ventricular mass index (LVM index), and maximal left atrial (LA) volume index. Measurements were repeated after 5.5 years.

Results

At baseline, diastolic dysfunction was found in 62% of the SSc patients. Follow-up time was 5.4 ± 1.2 years. A total of 6 patients died of heart failure. In univariate Cox regression analysis, age (HR = 1.08, p < 0.05), LVM index (HR = 1.07, p < 0.01), lateral E? (HR = 1.57, p = 0.05), and LA volume index (HR = 1.11, p < 0.01) were predictors of survival. During the follow-up, significant increase in LA volume index (27.5 ± 9.7 vs. 35.4 ± 10.6 cm³/m², p < 0.001) and E/E? was found (7.6 ± 2.5 vs. 8.7 ± 3.8, p < 0.05) while E? did not change (9.6 ± 2.6 vs. 9.2 ± 1.9 cm/s, NS). The increase in LA volume index showed positive correlation (r = 0.46, p < 0.05) while the decrease in E? values showed negative correlation (r = −0.54, p < 0.01) with the duration of the SSc.

Conclusion

In SSc patients, left ventricular diastolic dysfunction is highly prevalent and is associated with increased risk of mortality. Our data suggest that in the advanced phase of the disease, the myocardial fibrotic processes burns out while the increase of the filling pressure progresses continuously.     

Remodelado cardiaco inverso estructural y funcional en pacientes con aleteo auricular típico sometidos a ablación del istmo cavotricuspídeo

Introduction and objectives

The purpose of the present study is to determine the structural and functional cardiac changes that occur in patients at 1-year follow-up after ablation of typical atrial flutter.

Methods

We enrolled 95 consecutive patients referred for cavotricuspid isthmus ablation. Echocardiography was performed at ≤6 h post-procedure and 1-year follow-up.

Results

Of 95 patients initially included, 89 completed 1-year follow-up. Hypertensive cardiopathy was the most frequently associated condition (39%); 24% of patients presented low baseline left ventricular systolic dysfunction. We observed a significant reduction in right and left atrial areas, end-diastolic and end-systolic left ventricular diameters, and interventricular septum. We observed substantial improvement in right atrium contraction fraction and left ventricular ejection fraction, and a reduction in pulmonary hypertension. Changes in diastolic dysfunction pattern were observed: 60% of patients progressed from baseline grade III to grade I; at 1-year follow-up, this improvement was found in 81%. We found no structural differences between paroxysmal and persistent atrial flutter at baseline and 1-year follow-up, exception for basal diastolic function.

Conclusions

In patients with typical atrial flutter undergoing cavotricuspid isthmus catheter ablation, we found inverse structural and functional cardiac remodeling at 1-year follow-up with much improved left ventricular ejection fraction, right atrium contraction fraction, and diastolic dysfunction pattern.Full English text available from:www.revespcardiol.org     

Relación entre la presión arterial central y periférica con la masa ventricular izquierda en hipertensos

Introduction and objectives

The purpose of the present study was to assess the relationship of central and peripheral blood pressure to left ventricular mass.

Methods

Cross-sectional study that included 392 never treated hypertensive individuals. Measurement of office, 24-h ambulatory, and central blood pressure (obtained using applanation tonometry) and determination of left ventricular mass by echocardiography were performed in all patients.

Results

In a multiple regression analysis, with adjustment for age, gender and metabolic syndrome, 24-h blood pressure was more closely related to ventricular mass than the respective office and central blood pressures. Systolic blood pressures always exhibited a higher correlation than diastolic blood pressures in all 3 determinations. The correlation between left ventricular mass index and 24-h systolic blood pressure was higher than that of office (P<.002) or central systolic blood pressures (P<.002). Changes in 24-h systolic blood pressure caused the greatest variations in left ventricular mass index (P<.001).

Conclusions

In our population of untreated middle-aged hypertensive patients, left ventricular mass index is more closely related to 24-h ambulatory blood pressure than to office or central blood pressure. Central blood pressure does not enable us to better identify patients with left ventricular hypertrophy.Full English text available from:www.revespcardiol.org     

A pilot trial of autologous bone marrow mononuclear cell transplantation through grafting artery: A sub-study focused on segmental left ventricular function recovery and scar reduction

Background

Our preliminary study suggested that patients with chronic myocardial infarction (MI) and heart failure could potentially benefit from CABG combined with aBM-MNC by improving global left ventricular (LV) function. The purpose of this sub-study was to quantitatively evaluate the effectiveness of aBM-MNC transplantation during CABG in patients with chronic MI by intensively analyzing the global and segmental LV function, the scar, and the relationships between the function recovery and the scar transmural extent.

Methods

A randomized, double-blinded, placebo-controlled study was performed in 50 patients with chronic MI. The patients were randomly allocated into CABG with stem cell transplantation (group A) and CABG only (group B) groups. CMR assessments of global and segmental left ventricular function and scar tissue were performed before surgery and repeated at 12 months after CABG and aBM-MNC transplantation.

Results

The left ventricular ejection fraction (LVEF) improved by 13.5% and 8.0% in group A and B respectively (P = 0.04). Segmental analysis of regional LV function recovery indicated that more improvement in contractility was found in group A within the same degree of the infarct transmurality (P = 0.017) and showed a predominant interaction in the most severely affected segments (76–100%, P = 0.016). Decrease in infarct size between the two groups did not reach statistical difference (9.4% vs. 6.0%, P = 0.100).

Conclusions

CMR assessments revealed reversed ventricular remodeling and improved systolic function and scar reduction in patients who underwent aBM-MNC transplantation during CABG. And the conjunctional use of CABG and stem cell therapy could improve the left ventricular function in patients with chronic MI.     

Long-term follow-up after percutaneous treatment of the unprotected left main stenosis in high risk patients not suitable for bypass surgery

Introduction and objectives

Percutaneous coronary intervention is recommended in patients with unprotected left main stenosis non suitable for coronary artery bypass graft. Long-term follow-up of those patients remains uncertain.

Methods

All patients with de novo unprotected left main stenosis treated with stent implantation were consecutively enrolled. Percutaneous coronary intervention was indicated according to the standards of care, taking into account clinical and anatomical conditions unfavorable for coronary artery bypass graft. The primary end point was the occurrence of major adverse cardiac events, a composite of death, nonfatal acute myocardial infarction, or target lesion revascularization.

Results

Of 226 consecutive patients included, 202 (89.4%) were treated with drug-eluting stents. Mean age was 72.1 years, 41.1% had renal dysfunction, and mean Syntax score and EuroSCORE were 28.9 and 7.4, respectively. Angiographic and procedural success was achieved in 99.6% and 92.9% of patients. At 3 years, the rates of major adverse cardiac events, death, nonfatal acute myocardial infarction and target lesion revascularization were 36.2%, 25.2%, 8.4%, 8.0%, respectively. Target lesion revascularization was more frequently observed when ≥2 stents were implanted rather than a single stent (18.5% vs 5.8%, P=.03); and with bare metal stents rather than drug-eluting stents (13.0% vs 7.9%, P=.24). Definite stent thrombosis was observed in 2 patients (0.9%) and probable stent thrombosis in 7 (3.1%). Female sex, impaired left ventricular function, and use of bare metal stents were significantly related with all-cause mortality.

Conclusions

High-risk patients with unprotected left main stenosis treated with percutaneous coronary intervention presented with a high rate of major adverse cardiac events at long-term follow-up. Female sex, impaired left ventricular function, and use of bare metal stents were predictors of poor prognosis.Full English text available from:www.revespcardiol.org     

Eco-Doppler de ejercicio en pacientes con miocardiopatía hipertrófica. Factores determinantes de la limitación funcional

Introduction and objectives

At-rest echocardiography is a poor predictor of exercise capacity in patients with hypertrophic cardiomyopathy. We aimed to test the performance of treadmill exercise Doppler echocardiography in the prediction of functional limitations in these patients.

Methods

Eighty-seven consecutive patients with hypertrophic cardiomyopathy underwent treadmill exercise echocardiography with direct measurement of oxygen consumption. Both at rest and at peak exercise, the mitral inflow, mitral regurgitation, left ventricular outflow tract obstruction and mitral annulus velocities were assessed.

Results

Forty-three patients developed left ventricular outflow tract obstruction during exercise, which significantly decreased oxygen consumption (21.3 [5.7] mL/kg/min vs 24.6 [6.1] mL/kg/min; P=.012), and had greater left atrial volume (42.1 [14.5] mL/m² vs 31.1 [11.6] mL/m²; P<.001) and a higher degree of mitral regurgitation and E/E’ ratio during exercise. Exercise variables improved the predictive value of functional capacity (adjusted R² rose from 0.38 to 0.49). Independent predictors of oxygen consumption were age, left atrial volume, E/E’ ratio and the presence of left ventricular outflow tract obstruction. In a subset of patients without left ventricular outflow obstruction, only left ventricular and atrial volume indexes were independent predictors of exercise capacity.

Conclusions

In patients with hypertrophic cardiomyopathy, left ventricular outflow tract obstruction and left atrial volume are the main predictors of exercise capacity. Exercise echocardiography is a better predictor of functional performance than at-rest echocardiography, although its predictive power is under 50%. In nonobstructed patients, left atrial and ventricular volumes were the independent factors.Full English text available from:www.revespcardiol.org/en     

Left anterior descending coronary artery flow impaired by right ventricular apical pacing: The role of systolic dyssynchrony

Introduction

Right ventricular (RV) pacing may affect myocardial perfusion and coronary blood flow; however, it remains unknown whether this is related to systolic dyssynchrony induced by RV pacing. This prospective study was aimed to assess the relationship between dyssynchrony and the changes of coronary blood flow.

Methods

Seventy patients with sinus node dysfunction were prospectively enrolled. Coronary flow was evaluated by measuring diastolic velocity time integral (VTI) and duration at the distal-portion of left anterior descending coronary artery (LAD) with transthoracic echocardiography at baseline and follow-up. Systolic dyssynchrony was assessed with tissue Doppler imaging by time standard deviation to peak systolic velocity of 12 left ventricular segments (Ts-SD, cutoff value ≥ 33 ms).

Results

Adequate data for analysis was available from 65 patients. At follow-up (mean follow up time: 127 ± 45 days), LAD velocity-time integral (LAD-VTI: 12.1 ± 4.2 vs. 10.7 ± 4.6 cm, p < 0.001) was decreased and there was deterioration of left ventricular systolic function (left ventricular ejection fraction: 65 ± 7% vs. 62 ± 7%). However, these changes were only detected in those with RV pacing induced systolic dyssynchrony. Significant reduction of LAD-VTI (defined as ≥ 5%) occurred in 34 (52%) patients which was more prevalent in those with pacing-induced systolic dyssynchrony than those without (85.3% versus 16.1%, χ² = 31.1, p < 0.001). Though similar at baseline, LAD-VTI was significantly lower in the dyssynchrony group at follow up (p < 0.001). Cox-regression analysis showed that pacing-inducing systolic dyssynchrony [hazard ratio (HR): 3.62, p = 0.009] and higher accumulative pacing percentage (HR: 1.02, p = 0.002) were independently associated with reduction of LAD-VTI. ROC curve demonstrated that accumulative pacing percentage ≥ 35% was 97% sensitive and 84% specific in revealing significant reduction (area under the curve: 0.961, p < 0.001).

Conclusions

RV pacing induced dyssynchrony is associated with reduced coronary flow and this may account for, in part, the deleterious effect of RV pacing on ventricular function over time.     

Scar imaging using multislice computed tomography versus metabolic imaging by F-18 FDG positron emission tomography: A pilot study

Introduction

F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) FDG PET is an established metabolic imaging technique to assess myocardial viability. Delayed iodinated contrast enhancement (DE) of myocardium on computed tomography (CT) has also been shown to be an anatomical marker of nonviable myocardium. A pilot study was undertaken to determine quantitative and qualitative agreement between metabolic viability imaging and scar imaging using FDG PET and multislice CT respectively.

Methods

Fifteen patients with coronary artery disease and left ventricular dysfunction were recruited in the study. All patients underwent same day FDG PET and DECT to evaluate myocardial viability. The images were analyzed quantitatively and qualitatively using a 17 segment model.

Results

DECT diagnosed viability in 57% (146/255) whilst PET in 51% (129/255) of segments. The per-segment agreement between DECT and FDG PET on qualitative analysis was 70% (Kappa: 0.40). The agreement in quantitative measurements between the two techniques for viability showed modest correlation [Pearson ρ: 0.63; P < 0.0001] on scatter plot and the Passing–Bablok regression analysis. Higher agreement (70 vs 77%; P = 0.051; Kappa: 0.40 vs 0.53) was obtained with quantitative compared to qualitative DECT.

Conclusions

DECT may be useful in characterizing myocardial scar, and preliminary results correlate modestly with metabolic FDG PET, both qualitatively and quantitatively. Although in our study quantitative analysis offered superior agreement compared to qualitative with DECT, further studies are needed to determine its incremental value.     

Tratamiento anticoagulante en pacientes con insuficiencia cardiaca por disfunción sistólica y ritmo sinusal: análisis del registro REDINSCOR

Introduction and objectives

In patients with heart failure, left ventricular ejection fraction ≤35% and sinus rhythm without conditions such as atrial fibrillation, thrombus or history of thromboembolic events, the use of anticoagulation is controversial. Our objective was to evaluate the anticoagulation strategy in these patients, variables associated with its use, and its effects on various cardiovascular events.

Methods

Of the patients included in the REDINSCOR registry with left ventricular ejection fraction ≤35% and sinus rhythm without other anticoagulation indications (including patients with heart failure from 19 Spanish centres), we compared those who received this treatment with the remaining patients.

Results

Between 2007 and 2010, 2263 patients were included, of whom 902 had left ventricular ejection fraction ≤35% and sinus rhythm. Of these, 237 (26%) were receiving anticoagulation therapy. Variables associated with this treatment were a lower left ventricular ejection fraction, ischemic etiology, advanced functional class, wider QRS, larger left atrial diameter, and hospitalization. After 21(11-32) months of median follow-up, there were no significant differences in total mortality (14% versus 12.5%) or stroke (0.8% versus 0.9%). A propensity score adjusted multivariate analysis showed a reduction in a combined end-point including cardiac death, heart transplantation, coronary revascularization, and cardiovascular hospitalization (hazard ratio: 0.74; 95% confidence interval, 0.56-0.97; P=.03) in patients receiving anticoagulation therapy. No information regarding bleeding was collected in the follow-up.

Conclusions

In a large and contemporary series of patients with heart failure, left ventricular ejection fraction ≤35% and sinus rhythm, 26% received anticoagulation therapy. This was not associated with lower mortality or stroke incidence, although there was a reduction in major cardiac events.Full English text available from:www.revespcardiol.org