Downregulation of MicroRNA-126 Contributes to the Failing Right Ventricle in Pulmonary Arterial Hypertension.

BACKGROUND: Right ventricular (RV) failure is the most important factor of both morbidity and mortality in pulmonary arterial hypertension (PAH). However, the underlying mechanisms resulting in the failed RV in PAH remain unknown. There is growing evidence that angiogenesis and microRNAs are involved in PAH-associated RV failure. We hypothesized that microRNA-126 (miR-126) downregulation decreases microvessel density and promotes the transition from a compensated to a decompensated RV in PAH. METHODS AND RESULTS: We studied RV free wall tissues from humans with normal RV (n=17), those with compensated RV hypertrophy (n=8), and patients with PAH with decompensated RV failure (n=14). Compared with RV tissues from patients with compensated RV hypertrophy, patients with decompensated RV failure had decreased miR-126 expression (quantitative reverse transcription-polymerase chain reaction; P<0.01) and capillary density (CD31(+) immunofluorescence; P<0.001), whereas left ventricular tissues were not affected. miR-126 downregulation was associated with increased Sprouty-related EVH1 domain-containing protein 1 (SPRED-1), leading to decreased activation of RAF (phosphorylated RAF/RAF) and mitogen-activated protein kinase (MAPK); (phosphorylated MAPK/MAPK), thus inhibiting the vascular endothelial growth factor pathway. In vitro, Matrigel assay showed that miR-126 upregulation increased angiogenesis of primary cultured endothelial cells from patients with decompensated RV failure. Furthermore, in vivo miR-126 upregulation (mimic intravenous injection) improved cardiac vascular density and function of monocrotaline-induced PAH animals. CONCLUSIONS: RV failure in PAH is associated with a specific molecular signature within the RV, contributing to a decrease in RV vascular density and promoting the progression to RV failure. More importantly, miR-126 upregulation in the RV improves microvessel density and RV function in experimental PAH.

Feasibility of Valve-in-Valve Procedure for Degenerated St. Jude Medical Trifecta Bioprosthesis.

The valve-in-valve (ViV) procedure is an option for patients with symptomatic structural degeneration of a bioprosthesis and excessive reoperative risk. The risk of coronary obstruction appears to be increased if ViV is performed for certain pericardial prostheses in which the leaflets are mounted outside the stent posts. Herein is described a successful ViV for a degenerated Trifecta aortic bioprosthesis, and the technical considerations for performing a ViV procedure within such types of prosthesis are considered. Emphasis is placed on the importance of preoperative investigations (computed tomography scan-based measurements of coronary ostial height and of sinus of Valsalva diameters), and on the precise deployment of the valve (transapical approach with transesophageal echocardiography control) to minimize the risk of major complications. The presence of a failing Trifecta bioprosthesis should not be considered an absolute contraindication to ViV on the basis of the risk of coronary obstruction.

Spontaneous bacterial coronary sinus septic thrombophlebitis treated successfully medically.

A 38-year-old farmer was hospitalized for fever, chills, cough, and chest pain lasting for 7 days. Due to persistent symptoms, patient was referred to hospital. Blood cultures identified oxacillin-sensitive Staphylococcus aureus (OSSA). Transthoracic echocardiography (TTE) showed large pericardial effusion, a mobile heterogeneous mass originating from the coronary sinus ostium, no sign of valvular endocarditis. Pericardiocentesis was done carrying out purulent fluid, microbiological culture isolating an OSSA. Parenteral penicillin M was administered for 6 weeks. At the end of this antibiotherapy regimen, TTE showed no coronary sinus mass with complete vacuity of the coronary sinus vein and no pericardial effusion.

Effect of QRS duration and morphology on cardiac resynchronization therapy outcomes in mild heart failure: results from the Resynchronization Reverses Remodeling in Systolic Left Ventricular Dysfunction (REVERSE) study.

BACKGROUND: Cardiac resynchronization therapy (CRT) decreases mortality, improves functional status, and induces reverse left ventricular remodeling in selected populations with heart failure. We aimed to assess the impact of baseline QRS duration and morphology and the change in QRS duration with pacing on CRT outcomes in mild heart failure. METHODS AND RESULTS: Resynchronization Reverses Remodeling in Systolic Left Ventricular Dysfunction (REVERSE) was a multicenter randomized trial of CRT among 610 patients with mild heart failure. Baseline and CRT-paced QRS durations and baseline QRS morphology were evaluated by blinded core laboratories. The mean baseline QRS duration was 151±23 milliseconds, and 60.5% of subjects had left bundle-branch block (LBBB). Patients with LBBB experienced a 25.3-mL/m(2) mean reduction in left ventricular end-systolic volume index (P<0.0001), whereas non-LBBB patients had smaller decreases (6.7 mL/m(2); P=0.18). Baseline QRS duration was also a strong predictor of change in left ventricular end-systolic volume index with monotonic increases as QRS duration prolonged. Similarly, the clinical composite score improved with CRT for LBBB subjects (odds ratio, 0.530; P=0.0034) but not for non-LBBB subjects (odds ratio, 0.724; P=0.21). The association between clinical composite score and QRS duration was highly significant (odds ratio, 0.831 for each 10-millisecond increase in QRS duration; P<0.0001), with improved response at longer QRS durations. The change in QRS duration with CRT pacing was not an independent predictor of any outcomes after correction for baseline variables. CONCLUSION: REVERSE demonstrated that LBBB and QRS prolongation are markers of reverse remodeling and clinical benefit with CRT in mild heart failure. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00271154.

Sites of left and right ventricular lead implantation and response to cardiac resynchronization therapy observations from the REVERSE trial.

OBJECTIVES: The objective of this study is to ascertain the effects of the left (LV) and right (RV) ventricular lead tip position in response to cardiac resynchronization therapy (CRT). BACKGROUND: The REVERSE randomized trial examined the effects of CRT in patients with asymptomatic or mildly symptomatic heart failure (HF). METHODS: We analysed data collected from the active group (CRT-ON) of REVERSE in whom the precise locations of the LV and RV ventricular lead tips were determined from postoperative chest roentgenograms as part of a prespecified sub-study. LV position was classified as lateral or non-lateral, and apical or non-apical. RV position was classified as apical or non-apical. Echocardiographic LV end-systolic volume index (LVESVi), QRS duration, and clinical outcomes at 12-24 months of follow-up were evaluated with respect to the lead tip position. The primary trial endpoint was the proportion of patients with a worsened HF clinical composite response, scored as improved, unchanged, or worsened. RESULTS: Totally 346 patients included in this analysis were followed for a median of 12.6 months (interquartile range: 11.9-23.9 months). The proportion of worsened HF clinical composite response did not correlate with lead position, whereas a significantly greater decrease in the powered secondary endpoint of LVESVi was observed with the non-apical vs. the apical LV lead positions. CRT-paced QRS duration was significantly shorter than at baseline in patients with lateral vs. non-lateral LV position, as well non-apical vs. apical LV position. The incidence of composite endpoint of death and first hospitalization for HF was lower in the LV lateral than in the non-lateral (HR 0.44; 95% CI 0.19-0.99; P= 0.04), and in the LV non-apical than in the apical group (HR 0.27; 95% CI 0.11-0.63; P= 0.001). No significant differences were observed between RV apical and non-apical positions of the lead tip. CONCLUSIONS: A more favourable outcome of CRT with regard to LV reverse remodelling and the composite of time to death or first HF hospitalization was observed when the LV lead tip was implanted in the lateral wall, away from the apex, while the position of the RV lead tip was indifferent. The long-term change in QRS duration was significantly associated with the position of the LV lead tip. ClinicalTrials.gov Identifier: NCT00271154.

Real-time three-dimensional speckle tracking echocardiography: a novel technique to quantify global left ventricular mechanical dyssynchrony.

AIMS: left ventricular (LV) mechanical dyssynchrony (LVMD) has emerged as a therapeutic target using cardiac resynchronization therapy (CRT) in chronic heart failure patients. Current methods used to evaluate LVMD are technically challenging and do not assess all the components of LVMD simultaneously. We analysed real-time 3D speckle tracking (3DST) echocardiography as a novel method to assess LVMD. METHODS AND RESULTS: three-dimensional ST was performed in 60 unselected patients (71 ± 9 years old; 39% with ischaemic cardiomyopathy) who were referred to optimize and to control of a CRT device; implanted according to current guidelines (9 added to be excluded from the protocol). Two standardized conditions [right ventricular (RV) versus an optimized biventricular (BiV) pacing modality] were tested. These two pacing modalities lead to two distinct electrical activation patterns. We sought to test the capability of 3DST to distinguish these two patterns. The LV ejection fraction was 24 ± 9 in the RV mode and 29 ± 10% in BiV. By 3DST, we measured global end-systolic LV deformation and dyssynchrony (standard deviation of the time to peak/16 LV-segment). The 3D radial strain increased from 13.8 ± 5.7 in the RV to 15.9 ± 6.5% in theBiV mode, and the dyssynchrony index decreased from 15.1 ± 5.0 to 11.8 ± 4.1%. 3D longitudinal strain increased from -6.9 ± 2.8 in the RV to -7.8 ± 3.2% in the BiV mode, and the dyssynchrony index decreased from 14.2 ± 4.8 to 11.5 ± 5.0% (P < 0.01 for all). The 3D area strain (AS) increased from -15.4 ± 6 in the RV to -18.3 ± 7.0% in the BiV mode, and the dyssynchrony index decreased from 12.2 ± 5.1 to 9.5 ± 4.5% (P < 0.001 for all). CONCLUSION: When image quality is optimal, 3DST might offer a new rapid method to quantify global LVMD in CRT candidates. In a comparison of the utility of various 3D strain measurements, the 3D AS appears to be closed to the ideal parameter that we are looking for.

Impact of aortic stenosis on longitudinal myocardial deformation during exercise.

UNLABELLED: In aortic stenosis (AS), left ventricular (LV) adaptation to exercise has poorly been examined. Changes in LV ejection fraction may lack accuracy in identifying the presence of intrinsic myocardial impairment. AIMS: We sought to determine the impact of aortic stenosis (AS) on left ventricular (LV) longitudinal function at exercise in a series of asymptomatic patients with AS and preserved LV ejection fraction. METHODS AND RESULTS: Long-axis function was assessed at rest and at exercise by using 2D speckle tracking of myocardial deformation in 207 AS patients (aortic valve area 0.87 ± 0.19 cm²) and 43 aged-matched control subjects. When compared with control subjects, patients with AS have reduced longitudinal myocardial function at rest (-20.2 ± 2.7 vs. -15.4 ± 4.0%) and at peak exercise (-25.0 ± 3.7 vs. -16.5 ± 4.9%) (P < 0.0001 for both). Exercise changes in global longitudinal strain were correlated with changes in LV ejection in controls but not in patients with AS. Changes in LV global longitudinal strain during test were lower in AS patients with an abnormal response to exercise (-0.5 ± 2.7 vs. -1.5 ± 2.8%, P = 0.001). In multivariate analysis, a lower global longitudinal strain at rest (P = 0.04), a higher increase in mean trans-valvular pressure gradient (P < 0.001) at exercise, and smaller exercise-induced changes in global longitudinal strain (P < 0.001) were associated with an abnormal exercise test. CONCLUSION: In AS, subnormal LV function can be reliably identified by 2D strain imaging at rest and during a sub-maximal exercise. That sensitive measure of LV systolic function is depressed in AS and even more in patients having the most severe AS.

Improved diagnosis of post-operative myocardial infarction by contrast echocardiography after coronary artery bypass graft surgery.

OBJECTIVE: Contrast echocardiography is a more accurate means of assessment of left ventricular (LV) regional motion compared with non-enhanced echocardiography. Despite new tests, the diagnosis of post-operative myocardial infarction (MI) remains difficult. The aim of this study was to determine whether contrast echocardiography can facilitate this diagnosis. METHODS: We performed standard and contrast echocardiography in 79 consecutive patients before and up to 10 days after they underwent isolated coronary artery bypass graft (CABG) surgery. RESULTS: The post-operative intra- and interobserver reproducibility of echocardiographic measurements of the LV ejection fraction and wall motion score was significantly higher with than without contrast enhancement. The proportion of non-visualized LV myocardial segments was significantly greater with non-enhanced (6.6%) than with contrast (0.3%) echocardiography (P< 0.0001). The mean peak serum cardiac troponin (cTnI) concentration was significantly higher in the group of patients with new wall motion abnormalities detected with contrast-enhanced echocardiography. A correlation was found (r = -0.43, P< 0.01) between peak cTnI and changes in wall motion score only when a contrast agent was used. CONCLUSION: Contrast echocardiography facilitated the detection of new LV wall motion abnormalities after CABG. This observation, added to other markers, might facilitate the diagnosis of post-operative MI.

Mitochondriopathy: a rare aetiology of restrictive cardiomyopathy.

When diagnosing a restrictive hypertrophied cardiomyopathy, most echocardiographists consider cardiac amyloidosis as a possible cause, especially after the appearance of 'granular' sparkling echoes on a transthoracic echocardiography. However, other infiltrative diseases (i.e. metabolic myopathies, Gaucher, Hunter's, and Hurler's diseases) or storage cardiomyopathies (haemochromatosis, Fabry's disease, glycogen storage, and Niemann-Pick disease) should be considered. In this paper, we report on another unusual cause of restrictive cardiomyopathy of which all cardiologists should be aware.

Forward Left Ventricular Ejection Fraction: A Simple Risk Marker in Patients With Primary Mitral Regurgitation.

BACKGROUND: The timing of mitral valve surgery in asymptomatic patients with primary mitral regurgitation (MR) is controversial. We hypothesized that the forward left ventricular (LV) ejection fraction (LVEF; ie, LV outflow tract stroke volume divided by LV end-diastolic volume) is superior to the total LVEF to predict outcomes in MR. The objective of this study was to examine the association between echocardiographic parameters of MR severity and LV function and outcomes in patients with MR. METHODS AND RESULTS: The clinical and Doppler-echocardiographic data of 278 patients with ≥mild MR and no class I indication of mitral valve surgery at baseline were retrospectively analyzed. The primary study end point was the composite of mitral valve surgery or death. During a mean follow-up of 5.4±3.2 years, there were 147 (53%) events: 96 (35%) MV surgeries and 66 (24%) deaths. Total LVEF and global longitudinal strain were not associated with the occurrence of events, whereas forward LVEF (P<0.0001) and LV end-systolic diameter (P=0.0003) were. After adjustment for age, sex, MR severity, Charlson probability, coronary artery disease, and atrial fibrillation, forward LVEF remained independently associated with the occurrence of events (adjusted hazard ratio: 1.09, [95% confidence interval]: 1.02-1.17 per 5% decrease; P=0.01), whereas LV end-systolic diameter was not (P=0.48). CONCLUSIONS: The results of this study suggest that the forward LVEF may be superior to the total LVEF and LV end-systolic diameter to predict outcomes in patients with primary MR. This simple and easily measurable parameter may be useful to improve risk stratification and select the best timing for intervention in patients with primary MR.

Impact of left ventricular remodelling patterns on outcomes in patients with aortic stenosis.

AIMS: The objective of this study was to examine the association between the different patterns of left ventricular (LV) remodelling/hypertrophy on all-cause and cardiovascular mortality in patients with aortic stenosis (AS). METHODS AND RESULTS: In total, 747 consecutive patients (69 ± 14 years, 57% men) with AS and preserved LV ejection fraction were included in this study. According to LV mass index and relative wall thickness, patients were classified into four LV patterns: normal, concentric remodelling (CR), concentric hypertrophy (CH), and eccentric hypertrophy (EH). One hundred and sixteen patients (15%) had normal pattern, 66 (9%) had EH, 169 (23%) had CR, and 396 (53%) had CH. During a median follow-up of 6.4 years, 339 patients died (242 from cardiovascular causes). CH was associated with higher risk of all-cause mortality compared with the three other LV patterns (all P < 0.05). After multivariable adjustment, CH remained associated with higher risk of mortality (HR = 1.27, 95% CI 1.01-1.61, P = 0.046). There was a significant interaction (P < 0.05) between sex and CH with regards to the impact on mortality: CH was associated with worse outcome in women (P = 0.0001) but not in men (P = 0.22). In multivariable analysis, CH remained associated with higher risk of worse outcome in women (HR = 1.56, 95% CI 1.08-2.24, P = 0.018). CONCLUSIONS: This study shows that CH was independently associated with increased risk of mortality in AS patients with preserved ejection fraction. This association was observed in women but not in men. The pattern of LV remodelling/hypertrophy should be integrated in the risk stratification process in patients with AS.

Discordant Grading of Aortic Stenosis Severity: Echocardiographic Predictors of Survival Benefit Associated With Aortic Valve Replacement.

OBJECTIVES: This study sought to assess the survival benefit associated with aortic valve replacement (AVR) according to different strata of echocardiographic parameters of aortic stenosis (AS) severity, and especially in patients with an aortic valve area (AVA) comprised between 0.8 cm(2) and 1 cm(2). BACKGROUND: Discordant findings between AVA (≤1.0 cm(2)) and mean gradient (MG) (<40 mm Hg) raise uncertainty regarding the actual severity of AS. Some studies suggested that the AVA threshold value to define severe AS should be decreased to 0.8 cm(2) to reconcile these discordances. METHODS: A total of 1,710 patients with documented moderate to severe AS by Doppler echocardiography were separated into 4 strata of AS severity based alternatively on AVA, indexed AVA, MG, or peak aortic jet velocity (Vpeak). We compared the survival rates of medically versus surgically treated patients. To eliminate covariate differences that may lead to biased estimates of treatment effect, a propensity matching with a greedy 5-to-1 digit-matching algorithm was used. RESULTS: Mean AVA was 0.9 ± 0.3 cm(2), mean MG 33 ± 18 mm Hg, and mean Vpeak 3.6 ± 0.9 m/s. A total of 1,030 (60%) patients underwent AVR within 3 months following echocardiographic evaluation. During a mean follow-up of 4.4 ± 3.0 years there were 469 deaths. Patients with an AVA between 0.8 cm(2) and 1.0 cm(2) had a significant observed survival benefit with AVR (hazard ratio: 0.37 [95% confidence interval: 0.21 to 0.63]; p = 0.0002). AVR was also associated with improved survival in patients with MG between 25 mm Hg and 40 mm Hg or Vpeak between 3 m/s and 4 m/s, but only in patients with concomitant AVA ≤1 cm(2) (p = 0.001 vs. p = 0.46 in patients with AVA >1 cm(2)). CONCLUSIONS: These results do not support decreasing the AVA threshold value for severity to 0.8 cm(2) and they confirm that AVR is associated with improved survival in a substantial number of patients with discordant aortic grading.

Echocardiographic predictors of outcomes in adults with aortic stenosis.

OBJECTIVE: The study purpose was to assess the usefulness of echocardiographic parameters of aortic stenosis (AS) severity and left ventricular (LV) systolic function to predict mortality in AS. The main hypothesis is that parameters of LV systolic function are the most important independent predictors of mortality, whereas parameters of stenosis severity are not. METHODS: 1065 consecutive patients with AS referred to the echocardiography laboratory and meeting the inclusion/exclusion criteria were included and followed during 5.7 years. The end points were aortic valve replacement (AVR) (n=584), composite of AVR or death (n=932), all-cause mortality (n=550) and cardiovascular mortality (n=398). RESULTS: The most powerful echocardiographic predictors of valve-related events were parameters of AS severity, such as peak aortic jet velocity (VPeak), mean gradient (MG) and aortic valve area (AVA) (all p<0.001). Regarding mortality, the main predictors were LV ejection fraction (LVEF) and stroke volume index (SVi) (p<0.05). After multivariable adjustment, LVEF (p<0.001) and SVi (p=0.02) remained the only echocardiographic predictors of mortality, even after adjustment for symptomatic status. AVA was also associated with mortality, whereas VPeak and MG were not. CONCLUSIONS: The most powerful echocardiographic predictors of mortality are low LVEF and low flow, whereas AS severity parameters predict valve-related events but not overall mortality. Hence, low flow should be integrated in the risk stratification and therapeutic decision-making in patients with AS.

Impact of exercise pulmonary hypertension on postoperative outcome in primary mitral regurgitation.

AIMS: The management of asymptomatic patients with mitral regurgitation (MR) remains controversial. Exercise-induced pulmonary hypertension (ExPHT) was recently reported as a strong predictor of rapid onset of symptoms. We hypothesised that ExPHT is a predictor of postoperative cardiovascular events in patients with primary MR. METHODS AND RESULTS: One hundred and two patients with primary MR, no or mild symptoms (New York heart association (NYHA) ≤2), and no LV dysfunction/dilatation, were prospectively recruited in 3 centres and underwent exercise-stress echocardiography. The presence of ExPHT was defined as an exercise systolic pulmonary arterial pressure >60 mm Hg. All patients were closely followed up and operated on when indication for surgery was reached. Postoperative events were defined as the occurrence of atrial fibrillation (AF), stroke, cardiac-related hospitalisation or death. Among the 102 patients included, 59 developed ExPHT (58%). These patients were significantly older than those without ExPHT (p=0.01). During a mean postoperative follow-up of 50±23 months, 28 patients (26%) experienced a predefined cardiovascular event. Patients with ExPHT had significantly higher rate of postoperative events (39% vs 12%, p=0.005); the rate of events was still higher in these patients (32% vs 9%, p=0.013), even when excluding early postoperative AF (ie, within 48 h). Event-free survival was significantly lower in the ExPHT group (all events: 5-year: 60±8% vs 88±5%, p=0.007, events without early AF: 5-year: 67±7% vs 90±4%, p=0.02). Using Cox multivariable analysis, ExPHT remained independently associated with higher risk of postoperative events in all models (all p≤0.04). CONCLUSIONS: ExPHT is associated with increased risk of adverse cardiac events following mitral valve surgery in patients with primary MR.

Impact of Cardiac Resynchronization Therapy on Left Ventricular Mechanics: Understanding the Response through a New Quantitative Approach Based on Longitudinal Strain Integrals.

BACKGROUND: The mechanisms of improvement of left ventricular (LV) function with cardiac resynchronization therapy (CRT) are not yet elucidated. The aim of this study was to describe a new tool based on automatic quantification of the integrals of regional longitudinal strain signals and evaluate changes in LV strain distribution after CRT. METHODS: This was a retrospective observational study of 130 patients with heart failure before CRT device implantation and after 3 to 6 months of follow-up. Integrals of regional longitudinal strain signals (from the beginning of the cardiac cycle to strain peak [IL,peak] and to the instant of aortic valve closure [IL,avc]) were analyzed retrospectively with custom-made algorithms. Response to CRT was defined as a decrease in LV end-systolic volume of ≥15%. RESULTS: Responders (61%) and nonresponders (39%) showed similar baseline values of regional IL,peak and IL,avc. At follow-up, significant improvements of midlateral IL,peak and of midlateral IL,avc were noted only in responders. Midlateral IL,avc showed a relative increase of 151 ± 276% in responders, whereas a decrease of 33 ± 69% was observed in nonresponders. The difference between IL,avc and IL,peak (representing wasted energy of the LV myocardium) of the lateral wall showed a relative change of -59 ± 103% in responders between baseline and CRT, whereas in nonresponders, the relative change was 21 ± 113% (P = .009). CONCLUSIONS: Strain integrals revealed changes between baseline and CRT in the lateral wall, demonstrating the beneficial effects of CRT on LV mechanics with favorable myocardial reverse remodeling.

Evolution and prognostic impact of low flow after transcatheter aortic valve replacement.

OBJECTIVE: Low flow (LF), defined as stroke volume index (SVi) <35 mL/m(2), prior to the procedure has been recently identified as a powerful independent predictor of early and late mortality in patients undergoing transcatheter aortic valve replacement (TAVR). The objectives of this study were to determine the evolution of SVi following TAVR and to assess the determinants and impact on mortality of early postprocedural SVi (EP-SVi). METHODS: We retrospectively analysed the clinical, Doppler echocardiographic and outcome data prospectively collected in 255 patients who underwent TAVR. Echocardiograms were performed before (baseline), within 5 days after procedure (early post procedure) and 6 months to 1 year following TAVR (late post procedure). RESULTS: Patients with EP-SVi <35 mL/m(2) (n=138; 54%) had increased mortality (HR 1.97, p=0.003) compared with those with EP-SVi ≥35 mL/m(2) (n=117; 46%). Furthermore, patients with baseline SVi (B-SVi) <35 mL/m(2) and EP-SVI ≥35 mL/m(2), that is, normalised flow, had better survival (HR 0.46, p=0.03) than those with both B-SVi and EP-SVi <35 mL/m(2), that is, persistent LF, and similar survival compared with those with both B-SVi and EP-SVi ≥35 mL/m(2), that is, maintained normal flow. In a multivariable model analysis, EP-SVi was independently associated with increased risk of mortality (HR 1.41 per 10 mL/m(2) decrease, p=0.03). The preprocedural/intraprocedural factors associated with lower EP-SVi were lower B-SVi (standardised ß [ß] 0.36, p<0.001) atrial fibrillation (ß -0.13, p=0.02) and transapical approach (ß -0.22, p<0.001). CONCLUSIONS: The measurement of EP-SVi is useful to assess the immediate haemodynamic benefit of TAVR and to predict the risk of late mortality.

Cardiac magnetic resonance versus transthoracic echocardiography for the assessment and quantification of aortic regurgitation in patients undergoing transcatheter aortic valve implantation.

BACKGROUND: The transthoracic echocardiographic (TTE) evaluation of the severity of residual aortic regurgitation (AR) following transcatheter aortic valve implantation (TAVI) has been controversial and lacks validation. OBJECTIVES: This study sought to compare TTE and cardiac magnetic resonance (CMR) for assessment of AR in patients undergoing TAVI with a balloon-expandable valve. METHODS: TTE and CMR exams were performed pre-TAVI in 50 patients and were repeated postprocedure in 42 patients. All imaging data were analysed in centralised core laboratories. RESULTS: The severity of native AR as determined by multiparametric TTE approach correlated well with the regurgitant volume and regurgitant fraction determined by CMR prior to TAVI (Rs=0.79 and 0.80, respectively; p<0.001 for both). However, after TAVI, the correlation between the prosthetic AR severity assessed by TTE and regurgitant volume and fraction measured by CMR was only modest (Rs=0.59 and 0.59, respectively; p<0.001 for both), with an underestimation of AR severity by TTE in 61.9% of patients (1 grade in 59.5%). The TTE jet diameter in parasternal view and the multiparametric approach (Rs=0.62 and 0.59, respectively; both with p<0.001) showed the best correlation with CMR regurgitant fraction post-TAVI. The circumferential extent of prosthetic paravalvular regurgitation showed a poor correlation with CMR regurgitant volume and fraction (Rs=0.32, p=0.084; Rs=0.36, p=0.054, respectively). CONCLUSIONS: The severity of AR following TAVI with a balloon-expandable valve was underestimated by echocardiography as compared with CMR. The jet diameter, but not the circumferential extent of the leaks, and the multiparametric echocardiography integrative approach best correlated with CMR findings. These results provide important insight into the evaluation of AR severity post-TAVI.

Resolution of left bundle branch block-induced cardiomyopathy by cardiac resynchronization therapy.

OBJECTIVES: The study sought to describe a specific syndrome characterized by isolated left bundle branch block (LBBB) and a history of progressive left ventricular (LV) dysfunction, successfully treated by cardiac resynchronization therapy (CRT). BACKGROUND: Isolated LBBB in animals causes cardiac remodeling due to mechanical dyssynchrony, reversible by biventricular stimulation. However, the existence of LBBB-induced cardiomyopathy in humans remains uncertain. METHODS: Between 2007 and 2010, 375 candidates for CRT were screened and retrospectively included in this study if they met all criteria of a pre-defined syndrome, including: 1) history of typical LBBB for >5 years; 2) LV ejection fraction (EF) >50%; 3) decrease in LVEF to <40% and development of heart failure (HF) to NYHA functional class II to IV over several years; 4) major mechanical dyssynchrony; 5) no known etiology of cardiomyopathy; and 6) super-response to CRT with LVEF >45% and decrease in NYHA functional class at 1 year. RESULTS: The syndrome was identified in 6 patients (1.6%), 50.5 years of age on average at the time of LBBB diagnosis. HF developed over a mean of 11.6 years. At the time of referral, Doppler echocardiograms showed major mechanical dyssynchrony at left atrioventricular, interventricular, and left intraventricular levels. During CRT, NYHA functional class decreased, LV dimensions normalized and mechanical dyssynchrony was nearly resolved in all patients, and mean LVEF increased from 31 ± 12% to 56 ± 8% (p = 0.027). CONCLUSIONS: These observations support the existence of a specific LBBB-induced cardiomyopathy resolved by CRT. Its prevalence, time course, and risk factors need to be prospectively studied.

Strain analysis during exercise in patients with left ventricular hypertrophy: impact of etiology.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) and aortic stenosis (AS) may influence left ventricular (LV) systolic function, despite preservation of LV ejection fraction. The aim of this study was to determine the relative importance of cardiac afterload and myocardial hypertrophy in the potential dysfunction of myocardial deformation, at rest and during standardized exercise. METHODS: Patients with moderate to severe (≤ 1.5 cm(2)) asymptomatic AS and patients with HCM in sinus rhythm were prospectively studied using resting and exercise echocardiography during submaximal exercise. Myocardial deformations were assessed using two-dimensional strain. Exclusion criteria were altered LV ejection fraction (<50%), coronary artery disease, intra-LV obstruction > 30 mm Hg at rest, diastolic LV thickness ≥ 30 mm, and New York Heart Association class > II. Thus, 50 patients (25 with AS, 25 with HCM) were selected and matched for age, sex, rest and exercise blood pressure, degree of LV hypertrophy (defined by maximal wall thickness), and LV ejection fraction. RESULTS: Mean resting global longitudinal strain (GLS) was -14.9 ± 4.7% in patients with AS and -16.1 ± 3.9% in those with HCM (P = .30). During exercise (mean heart rate, 110 ± 10 beats/min), mean GLS was -13.9 ± 4.2% in patients with AS and -18.1 ± 5.4% in those with HCM (P = .004). GLS decreased in patients with AS but increased in those with HCM (ΔGLS, 0.9 ± 3.1% and -1.9 ± 3.2%, respectively, P = .003). The same results were observed for global circumferential strain. Mean resting global circumferential strain was -16.4 ± 5.8% in patients with AS and -17.9 ± 4.5% in those with HCM (P = .36). During exercise, mean global circumferential strain was -13.8 ± 4.1% in patients with AS and -18.6 ± 5.3% in those with HCM (P = .011). Afterload was higher, particularly during exercise, in patients with AS than in those with HCM. CONCLUSIONS: Longitudinal and circumferential LV deformation during exercise was lower in patients with AS compared with those with HCM, despite similar resting characteristics. The greater afterload observed in patients with AS led to reduced contractile reserve.