Left atrial mechanics strongly predict functional capacity assessed by cardiopulmonary exercise testing in subjects without structural heart disease

Left atrium function is essential for cardiovascular performance and is evaluable by two-dimensional speckle-tracking echocardiography (2D-STE). Our aim was to determine how echocardiographic parameters interrelate with exercise capacity and ventilatory efficiency in subjects with no structural heart disease. Asymptomatic volunteers, in sinus rhythm and with normal biventricular size and function, were recruited from a community-based population. Individuals with moderate-to-severe valvular disease, pulmonary hypertension, and history of cardiac disease were excluded. We performed a transthoracic echocardiogram and assessed left atrial (LA) and left ventricular (LV) mechanics via 2D-STE. Cardiopulmonary exercise testing by treadmill took place immediately thereafter. Peak oxygen uptake (VO₂) served as measure of functional capacity and ventilation/carbon dioxide output (VE/VCO₂) slope as surrogate of ventilation/perfusion mismatch. 20 subjects were included (age 51?±?14 years, male gender 65%). Peak VO₂ strongly correlated with age (r?=??0.83; P?<?0.01), with E/e′ ratio (r?=??0.72; P?<?0.01), and with LA reservoir- and conduit-phase mechanics, particularly with LA conduit strain rate (SR) (r?=??0.82; P?<?0.01), but showed no correlation with LA volume index or LV mechanics. A similar pattern of associations was identified for VE/VCO₂ slope. In multivariate analysis, LA conduit SR (β?=??0.69; P?=?0.02) emerged as sole independent correlate of peak VO₂, adjusted for age and for E/e′ ratio (adjusted r ² ?=?0.76; P?<?0.01). Conduit and reservoir components of LA mechanics displayed strong associations with peak VO₂ and VE/VCO₂ slope. LA conduit-phase SR seems best suited as echocardiographic marker of functional capacity in subjects with no structural heart disease.     

Regional contribution to ventricular stroke volume is affected on the left side,but not on the right in patients with pulmonary hypertension

To develop more sensitive measures of impaired cardiac function in patients with pulmonary hypertension (PH), since detection of impaired right ventricular (RV) function is important in these patients. With the hypothesis that a change in septal function in patients with PH is associated with altered longitudinal and lateral function of both ventricles, as a compensatory mechanism, we quantified the contributions of these parameters to stroke volume (SV) in both ventricles using cardiac magnetic resonance (CMR). Seventeen patients (10 females) evaluated for PH underwent right heart catheterization (RHC) and CMR. CMR from 33 healthy adults (13 females) were used as controls. Left ventricular (LV) atrioventricular plane displacement (AVPD) and corresponding longitudinal contribution to LVSV was lower in patients (10.8?±?3.2 mm and 51?±?12?%) compared to controls (16.6?±?1.9 mm and 59?±?9?%, p?<?0.0001 and p?<?0.01, respectively). This decrease did not differ in patient with ejection fraction (EF) >50?% and <50?% (p?=?0.5) and was compensated for by increased LV lateral contribution to LVSV in patients (49?±?13?% vs. 37?±?7?%, p?=?0.001). Septal motion contributed less to LVSV in patients (5?±?8?%) compared to controls (8?±?4?%, p?=?0.05). RV AVPD was lower in patients (12.0?±?3.6 mm vs. 21.8?±?2.2 mm, p?<?0.0001) but longitudinal and lateral contribution to RVSV did not differ between patients (78?±?17?% and 29?±?16?%) and controls (79?±?9?% and 31?±?6?% p?=?0.7 for both) explained by increased RV cross sectional area in patients. LV function is affected in patients with PH despite preserved global LV function. The decreased longitudinal contribution and increased lateral contribution to LVSV was not seen in the RV, contrary to previous findings in patients with volume loaded RVs.     

Association of native T1 times with biventricular function and hemodynamics in precapillary pulmonary hypertension

In precapillary pulmonary hypertension (PH) patients, we sought to (1) investigate the relationship between ventricular insertion point (VIP) T1 times, hemodynamic parameters, and biventricular function, and (2) determine the predictors of anterior and inferior VIP T1 time. Twenty-two patients with precapillary PH underwent 1.5-T cardiac MR, right heart catheterization (RHC), and echocardiography. A group of 10 healthy age- and sex-matched volunteers served as controls. Biventricular function, morphology and mass were obtained from short-axis cine images. Native T1 times at anterior, inferior VIP, septum and LV lateral wall were respectively derived from all subjects. Mixed venous oxygen saturation (SvO₂) was the strongest hemodynamic parameters correlating with anterior (r_p = ?0.67, P?=?0.001) and inferior VIP T1 time (r_p = ?0.81, P?<?0.001). Elevated VIP T1 times were associated with reduced right ventricular (RV) ejection fraction, RV longitudinal and transverse motion, and increased RV end-diastolic and end-systolic volume index. LV diastolic function, quantified as mitral E velocity, was negatively correlated with anterior, inferior VIP (r_p = ?0.55, P?=?0.01) and septal T1 times (r_p = ?0.50, P?=?0.02), and positively correlated with RV systolic function and wall motion. In multivariate linear regression analyses, systolic eccentricity index (sEI) was the independent predictor of average VIPs T1 time (β=?0.47, P?<?0.01), and remained significant correlation after adjustment of RHC and demographic parameters. In patients with precapillary PH, VIP T1 times are associated with biventricular function and hemodynamic parameters. Among all the parameters, sEI acts as a determinant of average VIPs T1 time.     

Decreased left atrial strain parameters are correlated with prolonged total atrial conduction time in lone atrial fibrillation

To investigate left atrium (LA) strain properties of patients with lone atrial fibrillation (LAF) and to assess relationships between LA strain parameters and total atrial conduction time measured with tissue Doppler imaging (PA-TDI). The study population consisted of 53 patients with LAF. The control group was comprised of 50 normal volunteers. Conventional echocardiography indices were measured. Mitral annular velocities and PA-TDI were assessed with TDI. Two-dimensional speckle-tracking echocardiography (2D-STE) was used to assess LA segmental strain and strain rate. Compared with the control group, PA-TDI was significantly prolonged and LA myocardial Ss, SRs, Sa, and SRa were significantly decreased in the LAF group (all P?<?0.001). In the control group, LA myocardial Ss (γ?=??0.486, P?<?0.01), SRs (γ?=??0.436, P?<?0.01), and Sa (γ?=??0.360, P?<?0.05) were correlated negatively with PA-TDI. LA myocardial SRa (γ?=?0.377, P?<?0.01) was correlated positively with PA-TDI. In the LAF group, LA myocardial Ss (γ?=??0.429, P?<?0.01), SRs (γ?=??0.468, P?<?0.01), and Sa (γ?=??0.380, P?<?0.05) were also correlated negatively, and SRa (γ?=?0.390, P?<?0.01) was correlated positively, with PA-TDI. Multivariate logistic regression identified PA-TDI as the only predictor of AF onset (OR 1.39; 95?% CI 1.02–1.54; P?<?0.01). LA strain parameters were decreased and PA-TDI was prolonged in patients with LAF. Structural remodeling of the LA, assessed by 2D-STE, was correlated with electrical remodeling, determined by PA-TDI. Prolonged PA-TDI was independently associated with AF onset.     

Cardiovascular magnetic resonance left ventricular strain in end-stage renal disease patients after kidney transplantation

Background

Cardiovascular disease is a significant cause of morbidity and mortality in patients with end-stage renal disease (ESRD) and kidney transplant (KT) patients. Compared with left ventricular (LV) ejection fraction (LVEF), LV strain has emerged as an important marker of LV function as it is less load dependent. We sought to evaluate changes in LV strain using cardiovascular magnetic resonance imaging (CMR) in ESRD patients who received KT, to determine whether KT may improve LV function.

Methods

We conducted a prospective multi-centre longitudinal study of 79 ESRD patients (40 on dialysis, 39 underwent KT). CMR was performed at baseline and at 12?months after KT.

Results

Among 79 participants (mean age 55 years; 30% women), KT patients had significant improvement in global circumferential strain (GCS) (p?=?0.007) and global radial strain (GRS) (p?=?0.003), but a decline in global longitudinal strain (GLS) over 12?months (p?=?0.026), while no significant change in any LV strain was observed in the ongoing dialysis group. For KT patients, the improvement in LV strain paralleled improvement in LVEF (57.4?±?6.4% at baseline, 60.6%?±?6.9% at 12?months; p?=?0.001). For entire cohort, over 12?months, change in LVEF was significantly correlated with change in GCS (Spearman’s r?=???0.42, p?<?0.001), GRS (Spearman’s r?=?0.64, p?<?0.001), and GLS (Spearman’s r?=???0.34, p?=?0.002). Improvements in GCS and GRS over 12?months were significantly correlated with reductions in LV end-diastolic volume index and LV end-systolic volume index (all p?<?0.05), but not with change in blood pressure (all p?>?0.10).

Conclusions

Compared with continuation of dialysis, KT was associated with significant improvements in LV strain metrics of GCS and GRS after 12?months, which did not correlate with blood pressure change. This supports the notion that KT has favorable effects on LV function beyond volume and blood pessure control. Larger studies with longer follow-up are needed to confirm these findings.

     

Assessment of right ventricular longitudinal strain by 2D speckle tracking imaging compared with RV function and hemodynamics in pulmonary hypertension

The right ventricular longitudinal strain (RVLS) of pulmonary hypertension (PH) patients and its relationship with RV function parameters measured by echocardiography and hemodynamic parameters measured by right heart catheterization was investigated. According to the WHO functional class (FC), 66 PH patients were divided into FC I/II (group 1) and III/IV (group 2). RV function parameters were measured by echocardiographic examinations. Hemodynamic parameters were obtained by right heart catheterization. Patients in group 2 had higher systolic pulmonary artery pressure (sPAP; P?<?0.05) than patients in group (1) significant between-group differences were observed in global RVLS (RVLS_global), free wall RVLS (RVLS_FW; P?<?0.01), and RV conventional function parameters (all P?<?0.05). Moreover, mPAP and PVR increased remarkably and CI decreased significantly in group (2) RVLS_global had a positive correlation with 6-min walking distance (6MWD; r?=?0.492, P?<?0.001) and N-terminal pro-brain natriuretic peptide (NT-proBNP; r?=?0.632, P?<?0.001), while RVLS_FW had a positive correlation with 6MWD (r?=?0.483, P?<?0.001) and NT-proBNP (r?=?0.627, P?<?0.001). Hemodynamics analysis revealed that RVLS_global had a positive correlation with mPAP (r?=?0.594, P?<?0.001), PVR (r?=?0.573, P?<?0.001) and CI (r?=?0.366, P?=?0.003), while RVLS_FW had a positive correlation with mPAP (r?=?0.597, P?<?0.001), PVR (r?=?0.577, P?<?0.001) and CI (r?=?0.369, P?=?0.002). According to receiver operating characteristic curves, the optimal cut-off values of RVLS_global (–15.0%) and RVLS_FW (–15.3%) for prognosis detection with good sensitivity and specificity. Evidence has shown that RVLS measurement can provide the much-needed and reliable information on RV function and hemodynamics. Therefore, this qualifies as a patient-friendly approach for the clinical management of PH patients.     

Relation between invasive hemodynamics and measured glomerular filtration rate by 51Cr-EDTA clearance in advanced heart failure

The interaction between hemodynamics and kidney function in heart failure (HF) is incompletely understood. We investigated the association between invasive hemodynamic parameters and measured glomerular filtration rate (mGFR) by plasma clearance of 51-chromium-labeled ethylenediamine tetra-acetic acid (⁵¹Cr-EDTA) in patients with advanced HF and tested the hypothesis that patients with reduced mGFR have lower cardiac index (CI) and mean arterial pressure (MAP) as well as higher central venous pressure (CVP) and pulmonary capillary wedge pressure (PCWP). We retrospectively studied 242 patients (mean age 50?±?13?years) referred for evaluation for heart transplantation or implantation of a left ventricular assist device with a left ventricular ejection fraction < 45% on optimal medical therapy, who underwent right heart catheterization (RHC) and measurement of ⁵¹Cr-EDTA clearance. Mean mGFR was 63?±?21?mL/min/1.73 m², CI was 2.3?±?0.7?L/min/m², PCWP was 21?±?9?mmHg, and CVP was 10.3?±?5.2?mmHg. Univariate analysis demonstrated a significant correlation between mGFR and CI (r² = 0.030, p?=?.007) and CVP (r² = 0.017, p?=?.049) but not between mGFR and MAP or PCWP. In multivariate analyses, none of the hemodynamic variables remained significantly associated with mGFR. While CVP and CI were correlated with mGFR in univariate analysis the results of analyses adjusted for multiple covariates suggest that hemodynamics are only correlated to renal function in advanced HF to a modest degree challenging the hypothesis that renal dysfunction in HF mainly is a consequence of renal congestion.     

Left atrial deformation as a potent predictor for paroxysmal atrial fibrillation in patients with end-stage renal disease

It is widely known that various factors contribute to left atrial (LA) mechanical dysfunction in patients with end stage renal disease (ESRD). However, the connection between atrial dysfunction and arrhythmic events such as paroxysmal atrial fibrillation (PAF), in this group of patients, remains unclear. The purpose of our study was to evaluate prospectively the association between LA deformation indices and PAF in ESRD patients. 79 patients (41 men, mean age 57?±?17) with ESRD and preserved left ventricular systolic function comprised the study population. All patients underwent a baseline comprehensive echocardiography study and were followed for a mean period of 16?±?5 months. PAF episodes, first and the following events, were reported. LA longitudinal strain reflecting LA reservoir function and LA longitudinal strain rate reflecting LA pump function were specifically evaluated as LA deformation indices of interest, using 2D speckle tracking echocardiography. At the end of follow up period nine patients died. 15 of the rest 70 reported one or more episodes of PAF. LA indexed volumes were significantly higher in patients with PAF (32?±?26 vs. 21.5?±?9 ml/m², p?=?0.002), mean LA strain was significantly reduced (17?±?7 vs. 27?±?9%, p?<?0.001) as well as mean LA stain rate (??1.19?±?0.5 vs. ??1.95?±?0.5 1/s, p?<?0.001). Multivariate analysis showed that LA strain rate when adjusted with age together with PAF history remained the single most significant echocardiographic parameter for PAF prediction. Impaired LA strain and LA strain rate are associated with PAF in ESRD patients. LA strain rate might be a better independent predictor of PAF, compared to standard echocardiographic indices. Further prospective studies are needed to validate its relevance in routine clinical practice.     

Early detection of cardiac alterations by left atrial strain in patients with risk for cardiac abnormalities with preserved left ventricular systolic and diastolic function

This study sought to examine whether early cardiac alterations could be detected by left atrial (LA) strain in patients with risk for cardiac abnormalities. In this cross-sectional and retrospective study, we included patients with (n?=?234) and without (n?=?48) risk for cardiac abnormalities (i.e. those with arterial hypertension, diabetes mellitus and/or a history of coronary artery disease) of similar age and with preserved left ventricular (LV) systolic and diastolic function according to standard criteria. LA strain was significantly altered in patients with risk for cardiac abnormalities in comparison to those without risk (29.2?±?8.6 vs. 38.5?±?12.6%; rate of impaired LA strain: 18.8% vs. 0%; all p?<?0.01) and was the most sensitive parameter to detect early LA alterations in comparison with other LA functional parameters (rate of impaired LA strain rate, LA total emptying fraction, and LA expansion index 3.8%, 7.3%, and 3.8%, respectively). Moreover, in patients with risk for cardiac abnormalities LA strain was altered even in the absence of subtle LV systolic and diastolic alterations (rates 13.9% and 6.8%), albeit to a lesser extent than in patients with an abnormal LV longitudinal systolic strain or abnormal mitral annular e′ velocities (rates 48.5% and 24.4%). Regarding the clinical relevance of these findings, an impaired LA strain (i.e. <?23%) was significantly linked to exertional dyspnea (OR 3.5 [1.7–7.0]) even adjusting the analyses by age, gender and subtle LV abnormalities. In conclusion, the findings from this study suggest that LA strain measurements could be useful to detect early cardiac alterations in patients with risk for cardiac abnormalities with preserved LV systolic and diastolic function and that these early LA strain alterations could be linked to exertional dyspnea.     

Relationship between left atrial appendage emptying and left atrial function using cardiac magnetic resonance in patients with atrial fibrillation: comparison with transesophageal echocardiography

To compare cardiac magnetic resonance (CMR) quantifications of left atrium (LA) function and left atrial appendage (LAA) emptying depending on the presence of LA spontaneous echogenic contrast (LA-SEC) on transesophageal echocardiography (TEE) in patients with atrial fibrillation (AF). A total of 48 patients with AF underwent sequential CMR examination and TEE in preparation for catheter ablation. The CMR protocol included cine and velocity encoding (VENC) sequences for evaluation of both LA function and LAA emptying. The peak blood velocity of LAA just before left ventricle systole was defined as the LAA emptying velocity (LAA-EV). Depending on the presence of LA-SEC on TEE, patients were divided into two groups, the SEC group (n?=?15) and the non-SEC group (n?=?33). Mean LAA-EV was significantly greater in the non-SEC group than in the SEC group (54.5?±?24.8 ml/s vs. 26.0?±?22.6 ml/s, P?<?0.01). LAA-EV had a significant positive relationship (P?<?0.05) with LAA backflow velocity, as assessed using TEE. Use of an optimal LAA-EV cutoff value of 35 ml/s to predict LA-SEC yielded a sensitivity of 80.0?%, a specificity of 75.7?%, and positive and negative predictive values of 58.8 and 83.9?%, respectively. Using VENC-CMR, LAA-EV is associated with LA function and can be useful for predicting LA-SEC in patients with AF.     

Validation of a rapid semi-automated method to assess left atrial longitudinal phasic strains on cine cardiovascular magnetic resonance imaging

Background

Abnormal left atrial (LA) function is a marker of cardiac dysfunction and adverse cardiovascular outcome, but is difficult to assess, and hence not, routinely quantified. We aimed to determine the feasibility and effectiveness of a fast method to measure long-axis LA strain and strain rate (SR) with standard cardiovascular magnetic resonance (CMR) compared to conventional feature tracking (FT) derived longitudinal strain.

Methods

We studied 50 normal controls, 30 patients with hypertrophic cardiomyopathy, and 100 heart failure (HF) patients, including 40 with reduced ejection fraction (HFrEF), 30 mid-range ejection fraction (HFmrEF) and 30 preserved ejection fraction (HFpEF). LA longitudinal strain and SR parameters were derived by tracking the distance between the left atrioventricular junction and a user-defined point at the mid posterior LA wall on standard cine CMR two- and four-chamber views. LA performance was analyzed at three distinct cardiac phases: reservoir function (reservoir strain ε_s and strain rate SR_s), conduit function (conduit strain ε_e and strain rate SR_e) and booster pump function (booster strain ε_a and strain rate SR_a).

Results

There was good agreement between LA longitudinal strain and SR assessed using the fast and conventional FT-CMR approaches (r?=?0.89 to 0.99, p?<?0.001). The fast strain and SRs showed a better intra- and inter-observer reproducibility and a 55% reduction in evaluation time (85?±?10 vs. 190?±?12 s, p?<?0.001) compared to FT-CMR. Fast LA measurements in normal controls were 35.3?±?5.2% for ε_s, 18.1?±?4.3% for ε_e, 17.2?±?3.5% for ε_a, and 1.8?±?0.4, ??2.0?±?0.5, ??2.3?±?0.6 s^??1 for the respective phasic SRs. Significantly reduced LA strains and SRs were observed in all patient groups compared to normal controls. Patients with HFpEF and HFmrEF had significantly smaller ε_s, SR_s, ε_e and SR_e than hypertrophic cardiomyopathy, and HFmrEF had significantly impaired LA reservoir and booster function compared to HFpEF. The fast LA strains and SRs were similar to FT-CMR for discriminating patients from controls (area under the curve (AUC)?=?0.79 to 0.96 vs. 0.76 to 0.93, p?=?NS).

Conclusions

Novel quantitative LA strain and SR derived from conventional cine CMR images are fast assessable parameters for LA phasic function analysis.

     

Quantification of left atrial strain and strain rate using Cardiovascular Magnetic Resonance myocardial feature tracking: a feasibility study

Background

Cardiovascular Magnetic Resonance myocardial feature tracking (CMR-FT) is a quantitative technique tracking tissue voxel motion on standard steady-state free precession (SSFP) cine images to assess ventricular myocardial deformation. The importance of left atrial (LA) deformation assessment is increasingly recognized and can be assessed with echocardiographic speckle tracking. However atrial deformation quantification has never previously been demonstrated with CMR. We sought to determine the feasibility and reproducibility of CMR-FT for quantitative derivation of LA strain and strain rate (SR) myocardial mechanics.

Methods

10 healthy volunteers, 10 patients with hypertrophic cardiomyopathy (HCM) and 10 patients with heart failure and preserved ejection fraction (HFpEF) were studied at 1.5 Tesla. LA longitudinal strain and SR parameters were derived from SSFP cine images using dedicated CMR-FT software (2D CPA MR, TomTec, Germany). LA performance was analyzed using 4- and 2-chamber views including LA reservoir function (total strain [?_s], peak positive SR [SRs]), LA conduit function (passive strain [?_e], peak early negative SR [SRe]) and LA booster pump function (active strain [?_a], late peak negative SR [SRa]).

Results

In all subjects LA strain and SR parameters could be derived from SSFP images. There was impaired LA reservoir function in HCM and HFpEF (?_s [%]: HCM 22.1?±?5.5, HFpEF 16.3?±?5.8, Controls 29.1?±?5.3, p?<?0.01; SRs [s^?1]: HCM 0.9?±?0.2, HFpEF 0.8?±?0.3, Controls 1.1?±?0.2, p?<?0.05) and impaired LA conduit function as compared to healthy controls (?_e [%]: HCM 10.4?±?3.9, HFpEF 11.9?±?4.0, Controls 21.3?±?5.1, p?<?0.001; SRe [s^?1]: HCM ?0.5?±?0.2, HFpEF ?0.6?±?0.1, Controls ?1.0?±?0.3, p?<?0.01). LA booster pump function was increased in HCM while decreased in HFpEF (?_a [%]: HCM 11.7?±?4.0, HFpEF 4.5?±?2.9, Controls 7.8?±?2.5, p?<?0.01; SRa [s^?1]: HCM ?1.2?±?0.4, HFpEF ?0.5?±?0.2, Controls ?0.9?±?0.3, p?<?0.01). Observer variability was excellent for all strain and SR parameters on an intra- and inter-observer level as determined by Bland-Altman, coefficient of variation and intraclass correlation coefficient analyses.

Conclusions

CMR-FT based atrial performance analysis reliably quantifies LA longitudinal strain and SR from standard SSFP cine images and discriminates between patients with impaired left ventricular relaxation and healthy controls. CMR-FT derived atrial deformation quantification seems a promising novel approach for the study of atrial performance and physiology in health and disease states.     

Left atrial remodelling in patients undergoing transcatheter aortic valve implantation: a speckle-tracking prospective, longitudinal study

Aortic stenosis (AS) results in several left ventricular (LV) disturbances as well as progressive left atrial (LA) enlargement and dysfunction. Transcatheter aortic valve implantation (TAVI) reverses LV remodelling and improves overall systolic function but its effect on LA function remains undetermined. The aim of this prospective, longitudinal study was to investigate the effects of TAVI on LA structure and function. We studied thirty-two patients with severe symptomatic AS who underwent TAVI, using standard and 2-dimensional speckle-tracking echocardiography before, at 40-day and at 3-month follow-up. Following TAVI, mean transvalvular gradient decreased (p < 0.001). Both LA area index and LA volume index decreased at 40-day follow-up (16.2 ± 6.4 vs. 12.5 ± 2.9 cm²/m², and 47.3 ± 12.0 vs. 42.8 ± 12.5 mL/m², respectively, p < 0.05) and values remained unchanged at 3 months. The reduction of LA size was accompanied by a significant increase in global peak atrial longitudinal strain (14.4 ± 3.9 vs. 19.1 ± 4.7 %, p < 0.001) and in global peak atrial contraction strain (8.4 ± 2.5 vs. 11.0 ± 4.1 %, p < 0.05) at 3-month follow-up. LA stiffness measurements significantly decreased 3 months after TAVI (0.93 ± 0.59 vs. 0.65 ± 0.37, respectively, p < 0.001). Trans-aortic mean gradient change and pre-procedural LA volume were identified as predictors of global peak atrial longitudinal strain increase (β = ?0.41, β = ?0.35, respectively, p < 0.0001) while pre-procedural LA volume and trans-aortic mean gradient change as predictor of LA volume index reduction 3 months after TAVI (β = ?0.37, β = ?0.28, respectively, p < 0.0001). TAVI is associated with significant recovery of LA structure and function suggesting a reverse cavity remodelling. Such functional recovery is primarily determined by the severity of pre-procedural valve stenosis.     

Predictors of left ventricular remodeling after ST-elevation myocardial infarction

Adverse left ventricular (LV) remodeling after acute ST-elevation myocardial infarction (STEMI) is associated with morbidity and mortality. We studied clinical, biochemical and angiographic determinants of LV end diastolic volume index (LVEDVi), end systolic volume index (LVESVi) and mass index (LVMi) as global LV remodeling parameters 4 months after STEMI, as well as end diastolic wall thickness (EDWT) and end systolic wall thickness (ESWT) of the non-infarcted myocardium, as compensatory remote LV remodeling parameters. Data was collected in 271 patients participating in the GIPS-III trial, presenting with a first STEMI. Laboratory measures were collected at baseline, 2 weeks, and 6–8 weeks. Cardiovascular magnetic resonance imaging (CMR) was performed 4 months after STEMI. Linear regression analyses were performed to determine predictors. At baseline, patients were 21% female, median age was 58 years. At 4 months, mean LV ejection fraction (LVEF) was 54?±?9%, mean infarct size was 9.0?±?7.9% of LVM. Strongest univariate predictors (all p?<?0.001) were peak Troponin T for LVEDVi (R²?=?0.26), peak CK-MB for LVESVi (R²?=?0.41), NT-proBNP at 2 weeks for LVMi (R²?=?0.24), body surface area for EDWT (R²?=?0.32), and weight for ESWT (R²?=?0.29). After multivariable analysis, cardiac biomarkers remained the strongest predictors of LVMi, LVEDVi and LVESVi. NT-proBNP but none of the acute cardiac injury biomarkers were associated with remote LV wall thickness. Our analyses illustrate the value of cardiac specific biochemical biomarkers in predicting global LV remodeling after STEMI. We found no evidence for a hypertrophic response of the non-infarcted myocardium.     

The association between the embolic load and atrial size in acute pulmonary embolism

Background: Early identification by computed tomography pulmonary angiography (CTPA) of patients with acute pulmonary embolism (PE) who have signs associated with a high embolic burden would be highly desirable. Objectives: To investigate whether an increased obstruction of the pulmonary vasculature is associated with reduced left atrial (LA) and increased right atrial (RA) areas. Methods: We retrospectively analyzed a consecutive series of CTPA studies of 137 patients with acute PE and 38 controls without PE between October 2004 and March 2006. Left and right atrial areas and longitudinal and short axis diameters were measured and correlated with the pulmonary arterial obstruction index (PAOI) divided into tertiles (obstruction of < 12.5%, 12.5%–42.5% and ≥ 42.5%). Results: There was a significant negative age‐ and gender‐adjusted correlation between the PAOI and LA measurements, particularly the LA area (r = ?0.259) and the LA short axis diameter (r = ?0.331). All RA measurements had positive correlations (RA area, r = 0.279; RA short axis diameter, r = 0.313). The LA/RA area ratio correlated negatively with the PAOI (r = ?0.447). All above‐mentioned correlations had P < 0.002. All the LA measurements were the largest in the controls and gradually decreased with higher PAOIs. A receiver operating characteristic curve analysis demonstrated that the RV/LV diameter, LA/RA area and LA/RA short axis diameter ratios had comparable discriminative ability for higher PAOI tertiles. Conclusions: The higher the clot load in the pulmonary arteries, the smaller the LA area and the larger the RA area. Atrial area measurements by CTPA may serve as a real‐time parameter in assessing the severity of PE upon diagnosis.     

Left heart longitudinal deformation analysis in mitral regurgitation

In mitral regurgitation (MR), left atrium (LA) and left ventricle (LV) undergo remodeling even if the patient is asymptomatic. The aim of our study was to identify the best echo index that correlates with MR severity in asymptomatic patients affected by MR. We enrolled 150 MR patients (50: mild, 50: moderate, 50: severe), asymptomatic for exertional dyspnea and 50 healthy controls. MR was graded using Doppler quantitative method. All underwent standard and Speckle Tracking Echocardiography (STE) with analysis of global peak atrial longitudinal strain (PALS), LV longitudinal strain (LS) and global atrio-ventricular strain (GAVS). LA dimensions showed significant differences between the groups while LV end-diastolic diameter did not significantly differ, although having a slight increase. PALS was slightly higher in patients with mild MR, while decreased in moderate and, mainly, in severe MR (controls 37.4?±?12.2%, mild MR 38.2?±?9%, moderate MR 29.1?±?9%, severe MR 19.8?±?10.6%, p?<?0.0001 by ANOVA); the same was found for GAVS (56.1?±?13%, 57.6?±?9.7%, 48.2?±?9% 39?±?9.4%, p?<?0.0001 by ANOVA). LV LS showed a tendency for gradual reduction in the three groups. In multivariate analysis, PALS and GAVS were far superior than GLS as predictors of MR groups. PALS emerged as an added value to the LA indexed volumes as predictor of MR severity. STE-derived PALS and GAVS emerged as promising tools to investigate heart longitudinal function in patients with chronic MR and no symptoms. PALS can represent a surplus in the prediction of severity of MR, in addition to the assessment of LA volumes.     

Cardiac function in patients with polymyositis or dermatomyositis: a three-dimensional speckle-tracking echocardiography study

Cardiac event is a major cause of death in patients with idiopathic inflammatory myopathies (IIM). The most frequent IIMs are polymyositis (PM) and dermatomyositis (DM). The purpose of this study was to analyze cardiac involvement by three-dimensional speckle-tracking echocardiography (3D STE) in patients with PM or DM, and to identify the relationship of cardiac injury with clinical characteristics and disease-specific parameters. 60 PM/DM patients with preserved left ventricular ejection fraction and 30 matched healthy controls were assessed by conventional echocardiography, 3D STE with biventricular strain analysis and electrocardiogram. Compared to controls, patients with PM/DM had significantly diminished left ventricular global longitudinal systolic strain and right ventricular longitudinal systolic strain (LVGLS, ? 20.3?±?2.5 vs. ? 23.4?±?1.7%; RVLS, ? 19.4?±?4.2 vs ? 24.8?±?2.0%; both P?<?0.001), and longer QTc intervals(421.0?±?38.4 vs 400.6?±?14.5 ms, P?=?0.001). Multiple regression analysis showed that Myositis Damage Index (MDI) was independently associated with LVGLS (R²?=?0.44, P?=?0.002) and RVLS (R²?=?0.56, P?<?0.001) in PM/DM patients with established disease course more than 1 year. In multivariate analysis of pooled data for all the PM/DM patients, when MDI was excluded due to missing observations, disease duration correlated with worse LVGLS (R²?=?0.24, P?=?0.002), while concomitant interstitial lung disease correlated with worse RVLS (R²?=?0.30, P?<?0.001). Disease activity scores (Myositis Intention to Treat Activities Index) had a weak positive correlation with QTc intervals (r_sp = 0.31, P?=?0.02). Our results suggest that cardiac injury in PM/DM is a long-term process and its severity depends on patients’ heterogeneous clinical features and systemic disease burden.     

Quantification of aortic stiffness in stroke patients using 4D flow MRI in comparison with transesophageal echocardiography

To quantify stiffness of the descending aorta (DAo) in stroke patients using 4D flow MRI and compare results with transesophageal echocardiography (TEE). 48 acute stroke patients undergoing 4D flow MRI and TEE were included. Intima-media-thickness (IMT) was measured in the DAo and the aorta was scrutinized for atherosclerotic plaques using TEE. Stiffness of the DAo was determined by (a) 4D flow MRI at 3 T by calculating pulse wave velocity (PWV) and by (b) TEE calculating arterial strain, stiffness index, and distensibility coefficient. Mean IMT was 1.43?±?1.75. 7 (14.6%) subjects had no sign of atherosclerosis, 10 (20.8%) had IMT-thickening or plaques?<?4 mm, and 31 (66.7%) had at least one large and/or complex plaque in the aorta. Increased IMT significantly correlated (p?<?0.001) with increased DAo stiffness in MRI (PWV r?=?0.66) and in TEE (strain r?=?0.57, stiffness index r?=?0.64, distensibility coefficient r?=?0.57). Patients with at least IMT-thickening had significantly higher stiffness values compared to patients without atherosclerosis. However, no difference was observed between patients with plaques?<?4 mm and patients with plaques?≥?4 mm. PWV and TEE parameters of stiffness correlated significantly [strain (r?=???0.36; p?=?0.011), stiffness index (r?=?0.51; p?=?0.002), and distensibility coefficient (r?=???0.59; p?<?0.001)]. 4D flow MRI and TEE-based parameters of aortic stiffness were associated with markers of atherosclerosis such as IMT-thickness and presence of plaques. We believe that 4D flow MRI is a promising tool for future studies of aortic atherosclerosis, due to its longer coverage of the aorta and non-invasiveness.     

Left atrial booster-pump function as a predictive parameter for new-onset postoperative atrial fibrillation in patients with severe aortic stenosis

Postoperative atrial fibrillation (POAF) is associated with increased risk of embolic events and heart failure, but its associated factors remains unknown. Left atrial (LA) subclinical mechanical dysfunction caused by the acute stress of surgery may be clinically manifested as POAF. The purpose of our study was therefore to test the hypothesis that preoperative LA subclinical myocardial dysfunction is a potential predictor of development of POAF in patients with aortic stenosis (AS). We studied 27 patients with severe AS undergoing aortic valve replacement (AVR) with left ventricular (LV) ejection fraction of 63 ± 11 %. All patients were in sinus rhythm and had no history of atrial fibrillation (AF). LA reservoir (SR-LAs), conduit (SR-LAe), and booster-pump (SR-LAa) functions were determined as the averaged global LA speckle-tracking longitudinal strain rates from apical four- and two-chamber views. POAF, defined as any episode of AF within 30-day after AVR, was observed in 15 patients (56 %). There were no differences in clinical characteristics, LA and LV volumes, and global LV function between patients with and without POAF. Multivariate logistic regression analysis identified SR-LAa as the only independent predictor of POAF. Furthermore, SR-LAa >0.79 s^?1 predicted POAF with 60 % sensitivity, 92 % specificity, and area under the curve of 0.828 (p < 0.0001). Of the 15 patients with POAF, one developed paroxysmal AF during long-term follow-up. In conclusions, SR-LAa helped to detect subtle LA booster-pump dysfunction and was associated with new-onset POAF in patients with severe AS. These findings may be useful for risk stratification and management of such patients.     

Intramyocardial dissecting hematoma in anterior wall ST elevation myocardial infarction: impact on left ventricular remodeling and prognosis

Intramyocardial dissecting hematoma is an uncommon complication of myocardial infarction potentially leading to cardiac rupture. The aim of the present study was to investigate coronary reperfusion results, left ventricular (LV) function recovery and remodeling and clinical outcomes in patients with anterior STEMI complicated by intramyocardial hematoma. We prospectively studied 87 patients (mean age 59?±?10 years; 88% male) with anterior STEMI (42 with intramyocardial hematoma) in order to evaluate coronary reperfusion results, LV remodeling (≥15% increase in end-systolic volume) and clinical outcomes (cardiac death, non-fatal reinfarction, and hospitalization for congestive heart failure) at 24 months. Thrombolysis in myocardial infarction (TIMI) flow score and myocardial blush grade (MBG) were assessed both pre- and post-percutaneous coronary intervention (PCI) and speckle-tracking echocardiography was performed post PCI and at 6-month follow-up. Patients with hematoma had lower post-PCI TIMI score and MBG, higher heart rate, worse LV ejection fraction and longitudinal or rotational function than their counterparts. LV remodeling occurred in 33 (78.6%) patients with hematoma and 11 (24.4%) patients without (p?<?0.001). Independent predictors of LV remodeling were heart rate (p?=?0.018), MBG (p?=?0.036) and presence of hematoma (p?<?0.001). Hematoma (log-rank test, χ²?=?9.849; p?=?0.002) and LV remodeling (log-rank test, χ²?=?13.770; p?<?0.001) were associated to a higher rate of adverse events. Cox analysis identified LV remodeling as the only independent predictor of adverse events (hazard ratio?=?3.912; 95% confidence interval, 1.429–10.714; p?=?0.008). Intramyocardial dissecting hematoma complicating anterior STEMI is an independent determinant of LV remodeling and is associated to poor prognosis.