Longitudinal strain assessed by cardiac magnetic resonance correlates to hemodynamic findings in patients with severe aortic stenosis and predicts positive remodeling after transcatheter aortic valve replacement

Myocardial Strain Measurements Derived From MR Feature-Tracking: Influence of Sex, Age, Field Strength, and Vendor

BACKGROUND

Cardiac magnetic resonance feature tracking (CMR-FT) is a novel technique for assessing myocardial deformation and dysfunction. However, a comprehensive assessment of normal values of strain parameters in all 4 cardiac chambers using different vendors is lacking.

OBJECTIVES

This study aimed to characterize the normal values for myocardial strain in all 4 cardiac chambers and identify factors that contribute to variations in FT strain through a systematic review and meta-analysis of the CMR-FT published reports.

METHODS

The investigators searched PubMed, Embase, and Scopus for myocardial strains of all 4 chambers measured by CMR-FT in healthy adults. The pooled means of all strain parameters were generated using a random-effects model. Subgroup analyses and meta-regressions were performed to identify the sources of variations.

RESULTS

This meta-analysis included 44 studies with a total of 3,359 healthy subjects. The pooled means of left ventricular global longitudinal strain (LV-GLS), LV global radial strain, and LV global circumferential strain (GCS) were -18.4% (95% CI: -19.2% to -17.6%), 43.7% (95% CI: 40.0%-47.4%), and -21.4% (95% CI: -22.3% to -20.6%), respectively. The pooled means of left atrial (LA)-GLS (corresponding to total strain, passive strain, and active strain) were 34.9% (95% CI: 29.6%-40.2%), 21.3% (95% CI: 16.6%-26.1%) and 14.3% (95% CI: 11.8%-16.8%), respectively. The pooled means of right ventricular (RV)-GLS and right atrial global longitudinal total strain were -24.0% (95% CI: -25.8% to -22.1%) and 36.3% (95% CI: 15.5%-57.0%), respectively. Meta-regression identified field strength (P < 0.001; I2 = 98.6%) and FT vendor (P < 0.001; I2 = 98.5%) as significant confounders contributing to heterogeneity of LV-GLS. The variations of LA-GLSactive were associated with regional distribution (P < 0.001; I2 = 97.3%) and FT vendor (P < 0.001; I2 = 97.4%). Differences in FT vendor were attributed to variations of LV-GCS and RV-GLS (P = 0.02; I2 = 98.8% and P = 0.01; I2 = 93.8%).

CONCLUSIONS

This study demonstrated the normal values of CMR-FT strain parameters in all 4 cardiac chambers in healthy subjects. Differences in FT vendor contributed to the heterogeneity of LV-GLS, LV-GCS, LA-GLSactive, and RV-GLS, whereas sex, age, and MR vendor had no effect on the normal values of CMR-FT strain measurements.

[Predictive value of cardiac magnetic resonance imaging for adverse left ventricular remodeling after acute ST-segment elevation myocardial infarction]

OBJECTIVE

To assess the value of cardiac magnetic resonance (CMR) imaging for predicting adverse left ventricular remodeling in patients with ST-segment elevation myocardial infarction (STEMI).

METHODS

We retrospectively analyzed the clinical data and serial CMR (cine and LGE sequences) images of 86 STEMI patients within 1 week and 5 months after percutaneous coronary intervention (PCI), including 25 patients with adverse LV remodeling and 61 without adverse LV remodeling, defined as an increase of left ventricular end-systolic volume (LVESV) over 15% at the second CMR compared to the initial CMR. The CMR images were analyzed for LV volume, infarct characteristics, and global and infarct zone myocardial function. The independent predictors of adverse LV remodeling following STEMI were analyzed using univariate and multivariate Logistic regression methods.

RESULTS

The initial CMR showed no significant differences in LV volume or LV ejection fraction (LVEF) between the two groups, but the infarct mass and microvascular obstructive (MVO) mass were significantly greater in adverse LV remodeling group (P < 0.05). Myocardial injury and cardiac function of the patients recovered over time in both groups. At the second CMR, the patients with adverse LV remodeling showed a significantly lower LVEF, a larger left ventricular end-systolic volume index (LVESVI) and a greater extent of infarct mass (P < 0.001) with lower global peak strains and strain rates in the radial, circumferential, and longitudinal directions (P < 0.05), infarct zone peak strains in the 3 directions, and infarct zone peak radial and circumferential strain rates (P < 0.05). The independent predictors for adverse LV remodeling following STEMI included the extent of infarct mass (AUC=0.793, 95% CI: 0.693-0.873; cut-off value: 30.67%), radial diastolic peak strain rate (AUC=0.645, 95% CI: 0.534-0.745; cut-off value: 0.58%), and RAAS inhibitor (AUC= 0.699, 95% CI: 0.590-0.793).

CONCLUSION

The extent of infarct mass, peak radial diastolic strain rate, and RAAS inhibitor are independent predictors of adverse LV remodeling following STEMI.

Is there a role for cardiovascular magnetic resonance imaging in the assessment of biological aortic valves?

Patients with biological aortic valves (following either surgical aortic valve replacement [SAVR] or trans catheter aortic valve implantation [TAVI]) require lifelong follow-up with an imaging modality to assess prosthetic valve function and dysfunction. Echocardiography is currently the first-line imaging modality to assess biological aortic valves. In this review, we discuss the potential role of cardiac magnetic resonance imaging (CMR) as an additional imaging modality in situations of inconclusive or equivocal echocardiography. Planimetry of the prosthetic orifice can theoretically be measured, as well as the effective orifice area, with potential limitations, such as CMR valve-related artefacts and calcifications in degenerated prostheses. The true benefit of CMR is its ability to accurately quantify aortic regurgitation (paravalvular and intra-valvular) with a direct and reproducible method independent of regurgitant jet morphology to accurately assess reverse remodelling and non-invasively detect focal and interstitial diffuse myocardial fibrosis. Following SAVR or TAVI for aortic stenosis, interstitial diffuse fibrosis can regress, accompanied by structural and functional improvement that CMR can accurately assess.

Shifting from Left Ventricular Ejection Fraction to Strain Imaging in Aortic Stenosis

Adverse ventricular remodeling is an inflexion point of disease progression in aortic stenosis (AS) and a major determinant of prognosis. Intervention before irreversible myocardial damage is of paramount importance to sustain favorable post-operative outcomes. Current guidelines recommend a left ventricular ejection fraction (LVEF)-based strategy to determine the threshold for intervention in AS. However, LVEF has several pitfalls: it denotes the left ventricular cavity volumetric changes and it is not suited to detecting subtle signs of myocardial damage. Strain has emerged as a contemporary imaging biomarker that describes intramyocardial contractile force, providing information on subclinical myocardial dysfunction due to fibrosis. A large body of evidence advocates its use to determine the switch from adaptive to maladaptive myocardial changes in AS, and to refine thresholds for intervention. Although mainly studied in echocardiography, studies exploring the role of strain in multi-detector row computed tomography and cardiac magnetic resonance are emerging. This review, therefore, summarizes contemporary evidence on the role of LVEF and strain imaging in AS prognosis, aiming to move from an LVEF-based to a strain-based approach for risk stratification and therapeutic decision-making in AS.

Cardiac MRI in Fabry disease

Fabry disease is a rare, progressive X-linked inherited disorder of glycosphingolipid metabolism due to a deficiency of α-galactosidase A enzyme. It leads to the accumulation of globotriaosylceramide within lysosomes of multiple organs, predominantly the vascular, renal, cardiac, and nervous systems. Fabry cardiomyopathy is characterized by increased left ventricular wall thickness/mass, functional abnormalities, valvular heart disease, arrhythmias, and heart failure. Early diagnosis and treatment are critical to avoid cardiac or renal complications that can significantly reduce life expectancy in untreated FD. This review will focus on the role of cardiovascular magnetic resonance imaging in the diagnosis, clinical decision-making, and monitoring of treatment efficacy.

Evaluation of right ventricular myocardial strain in pulmonary arterial hypertension associated with atrial septal defect by cardiac magnetic resonance feature tracking

We aimed to research the role of right ventricular strain parameters (RVSP) quantified by cardiac magnetic resonance feature tracking (CMR-FT) in the early assessment of right ventricular (RV) function in patients with pulmonary arterial hypertension associated with atrial septal defect (PAH-ASD). From September 2017 to May 2021, we retrospectively enrolled 41 patients with PAH-ASD and 20 healthy controls. All subjects underwent CMR-FT, and right heart catheterization was conducted in patients with PAH-ASD. The relationship between RVSP and RV functional parameters was subjected to correlation analysis, and intragroup correlation coefficient (ICC) and Bland-Altman plots were used to assess the consistency. The subjects were divided into three groups: Group A (controls; n = 20), Group B (PAH-ASD, RVEF ≥ 45%; n = 14), and Group C (PAH-ASD, RVEF < 45%; n = 27). Compared with healthy controls, the RV global longitudinal strain (GLS) in Group B was significantly decreased (- 19.68 ± 2.72% vs. - 25.21 ± 3.6%, P < 0.05). In RVEF-preserved PAH-ASD patients (Group B), compared with patients with GLS ≤ - 20%, patients with GLS > - 20% also had significantly elevated right ventricular end-diastolic pressure (RVEDP) [8 (6.5-8.25) mmHg vs. 4.5 ± 1.64 mmHg, P < 0.05]. RV GLS had a moderate to strong correlation with RVEF, RVESVi, RVEDVi, RVEDP, and NT-proBNP (P < 0.05). ICC and Bland-Altman plots showed good intragroup and intergroup consistency in radial, circumferential and longitudinal strains of RV. In conclusion, it is feasible to quantify RV strain in patients with PAH-ASD by CMR-FT, and GLS is valuable for the early assessment of RV dysfunction in patients with PAH-ASD.

Acute phase segmental radial strain correlates with recovery and late gadolinium extent in ST-elevation myocardial infarction (STEMI): analysis of the abciximab intracoronary versus intravenously drug application in STEMI substudy

Background

The role of regional strain evaluation in patients with acute reperfused ST-elevation myocardial infarction (STEMI) is not well determined. The objective of this study was the description of regional strain characteristics in the acute and chronic phase of myocardial infarction and its correlation with symptom-to-balloon time and final extent of myocardial scar assessed by cardiac magnetic resonance imaging.

Methods

The study cohort has been derived from the randomized controlled Abciximab Intracoronary versus Intravenously Drug Application in STEMI (AIDA STEMI) trial enrolled at the University of Ulm. All patients received comprehensive cardiac magnetic resonance imaging examinations in the acute phase and 6 months later.

Results

There was a significant improvement of all global deformation indices over time (global longitudinal strain: -13.1%±5.1% to -15.5%±5.8%, P=0.001; global circumferential strain: -14.4%±3.7% to -16.8%±3.6%, P<0.0001; global radial strain: 28.1%±8.7% to 31.9%±9.2%, P=0.0002). Mean radial strain of ischemic segments significantly improved (16.6%±10.8% to 23.7%±12.8%, P<0.0001), while mean radial strain of remote segments remained unchanged (40.2%±9.4% to 39.4%±9.4%, P=0.570). There was a significant correlation between acute phase radial strain of ischemic segments and either symptom-to-balloon time (P=0.013), as well as extent of late gadolinium enhancement at follow-up (P<0.0001). Using a cut-off of ≤27%, acute phase radial strain predicted infarction of the corresponding segment with high sensitivity and specificity (74.4% and 69.0% respectively, P<0.001).

Conclusions

Segmental radial strain in the acute phase of infarction showed a significant correlation to either symptom-to-balloon-time and the extent of late gadolinium enhancement at follow-up, thus potentially serving as early surrogate for left ventricular remodeling and outcome in STEMI.

Advanced cardiovascular multimodal imaging and aortic stenosis

Aortic valve stenosis has become the most common valvular heart disease on account of aging population and increasing life expectancy. Echocardiography is the primary diagnosis tool for this, but it still has many flaws. Therefore, advanced cardiovascular multimodal imaging techniques are continuously being developed in order to overcome these limitations. Cardiac magnetic resonance imaging (CMR) allows a comprehensive morphological and functional evaluation of the aortic valve and provides important data for the diagnosis and risk stratification in patients with aortic stenosis. CMR can functionally assess the aortic flow using two-dimensional and time-resolved three-dimensional velocity-encoded phase-contrast techniques. Furthermore, by late gadolinium enhancement and T1-mapping, CMR can reveal the presence of both irreversible replacement and diffuse interstitial myocardial fibrosis. Moreover, its role in guiding aortic valve replacement procedures is beginning to take shape. Recent studies have rendered the importance of active and passive biomechanics in risk stratification and prognosis prediction in patients with aortic stenosis, but more work is required is just in its infancy, but data are promising. In addition, cardiac computed tomography is particularly useful for the diagnosis of aortic valve stenosis, and in preprocedural evaluation of the aorta, while positron emission tomography can be also used to assess valvular inflammation and active calcification. The purpose of this review is to provide a comprehensive overview of current available data regarding advanced cardiovascular multimodal imaging in aortic stenosis.

Cardiac Magnetic Resonance Feature Tracking in Aortic Stenosis: Exploration of Strain Parameters and Prognostic Value in Asymptomatic Patients with Preserved Ejection Fraction

Objective

To determine the most valuable cardiac magnetic resonance feature tracking (CMR-FT) parameters for evaluating aortic stenosis (AS) and determine whether they can predict the prognosis in asymptomatic AS patients with preserved ejection fraction (pEF).

Materials and Methods

A prospective cohort of 123 moderate to severe AS patients (60 males, 68.6 ± 9.2 years) and 32 control subjects (14 males, 67.9 ± 4.4 years) underwent echocardiography and 3T CMR imaging from 2011–2015. CMR cine images were analyzed using CMR-FT to assess the left ventricular radial, circumferential, and longitudinal peak strain (PS) in 2- and 3-dimensions. The primary endpoints were clinical cardiac events (CCEs), including cardiac death, heart failure, and AS-associated symptom development. For statistical analysis, logistic regression and log-rank tests were used.

Results

Global PSs differed between AS patients and controls and between severe and moderate AS patients (p < 0.05). Two-dimensional (2D) global radial and longitudinal PSs changed gradually with the severity of AS groups (p < 0.001). Twenty-two of 67 asymptomatic AS patients with pEF experienced CCEs during the follow-up (median: 31.1 months). 2D global longitudinal PS (GLPS) was the single risk factor for CCE (p = 0.017). The relative risk for CCE was 3.9 (p = 0.016, 95% confidence interval: 1.2–11.9) based on 2D GLPS with a cutoff of −17.9% according to receiver operating characteristic curve analysis. Survival analysis demonstrated that asymptomatic AS patients with pEF having impaired 2D GLPS experienced worse event-free survival than the others (p = 0.041).

Conclusion

2D global longitudinal and radial PSs may reflect cardiac dysfunction according to the degree of AS. 2D GLPS might be a prognostic predictor of CCEs in asymptomatic AS patients with pEF.

Test–retest reliability of left and right ventricular systolic function by new and conventional echocardiographic and cardiac magnetic resonance parameters

Aims 

Reproducible evaluation of left (LV) and right ventricular (RV) function is crucial for clinical decision-making and risk stratification. We evaluated whether speckle-tracking echocardiography (STE) and cardiac magnetic resonance feature-tracking (cMR-FT) global longitudinal (GLS) and circumferential strains allow better test–retest reproducibility of LV and RV systolic function than conventional cMR and echocardiographic parameters.

Methods and results 

Thirty healthy volunteers and 20 chronic heart failure patients underwent cMR and STE twice on separate days to evaluate test–retest coefficient of variation (CV), intraclass correlation coefficient (ICC) and estimated sample sizes for significant changes in LV and RV function. Among LV parameters, cMR-left ventricular ejection fraction (LVEF) had the highest reproducibility (CV = 6.7%, ICC = 0.98), significantly better than cMR-FT-GLS (CV = 15.1%, ICC = 0.84), global circumferential strains (CV = 11.5%, ICC = 0.94) and echocardiographic LVEF (CV = 11.3%, ICC = 0.93). STE-LV-GLS (CV = 8.9%, ICC = 0.94) had significantly better reproducibility than cMR-FT-LV-GLS. Among RV parameters, STE-RV-GLS (CV = 7.3%, ICC = 0.93) had significantly better CV than cMR-right ventricular ejection fraction (RVEF) (CV = 13%, ICC = 0.82). cMR-FT-RV-GLS (CV = 43%, ICC = 0.39) performed poorly with significantly lower reproducibility than all other RV parameters. Owing to their superior interstudy reproducibility, cMR-LVEF (n = 12), cMR-RVEF (n = 41), STE-LV-GLS and STE-RV-GLS (both n = 14) were the parameters allowing the lowest calculated sample sizes to detect 10% change in LV or RV systolic function.

Conclusion 

STE-LV-GLS and STE-RV-GLS showed higher test–retest reliability than other echocardiographic measurements of LV and RV function. They also allowed smaller calculated sample sizes, supporting the use of STE-LV and RV-GLS for longitudinal follow-up of LV and RV function.

Global longitudinal strain by feature tracking for optimized prediction of adverse remodeling after ST-elevation myocardial infarction

BACKGROUND

The role of left ventricular (LV) myocardial strain by cardiac magnetic resonance feature tracking (CMR-FT) for the prediction of adverse remodeling following ST-elevation myocardial infarction (STEMI), as well as its prognostic validity compared to LV ejection fraction (LVEF) and CMR infarct severity parameters, is unclear. This study aimed to evaluate the independent and incremental value of LV strain by CMR-FT for the prediction of adverse LV remodeling post-STEMI.

METHODS

STEMI patients treated with primary percutaneous coronary intervention were enrolled in this prospective observational study. CMR core laboratory analysis was performed to assess LVEF, infarct pathology and LV myocardial strain. The primary endpoint was adverse remodeling, defined as ≥ 20% increase in LV end-diastolic volume from baseline to 4 months.

RESULTS

From the 232 patients included, 38 (16.4%) reached the primary endpoint. Global longitudinal strain (GLS), global radial strain, and global circumferential strain were all predictive of adverse remodeling (p < 0.01 for all), but only GLS was an independent predictor of adverse remodeling (odds ratio: 1.36[1.03-1.78]; p = 0.028) after adjustment for strain parameters, LVEF and CMR markers of infarct severity. A GLS > - 14% was associated with a fourfold increase in the risk for LV remodeling (odds ratio: 4.16[1.56-11.13]; p = 0.005). Addition of GLS to a baseline model comprising LVEF, infarct size and microvascular obstruction resulted in net reclassification improvement of 0.26 ([0.13-0.38]; p < 0.001) and integrated discrimination improvement of 0.02 ([0.01-0.03]; p = 0.006).

CONCLUSIONS

In STEMI survivors, determination of GLS using CMR-FT provides important prognostic information for the development of adverse remodeling that is incremental to LVEF and CMR markers of infarct severity.

CLINICAL TRIAL REGISTRATION

NCT04113356.

Comprehensive MR Analysis of Cardiac Function, Aortic Hemodynamics and Left Ventricular Strain in Pediatric Cohort with Isolated Bicuspid Aortic Valve

Bicuspid aortic valve (BAV) disease demonstrates a range of clinical presentations and complications. We aim to use cardiac MRI (CMR) to evaluate left ventricular (LV) parameters, myocardial strain and aortic hemodynamics in pediatric BAV patients with and without aortic stenosis (AS) or regurgitation (AR) compared to tricuspid aortic valve (TAV) controls. We identified 58 pediatric BAV patients without additional cardiovascular pathology and 25 healthy TAV controls (15.3 ± 2.2 years) who underwent CMR with 4D flow. BAV cohort included subgroups with no valvulopathy (n = 13, 14.3 ± 4.7 years), isolated AS (n = 19, 14.5 ± 4.0 years), mixed valve disease (AS + AR) (n = 13, 17.1 ± 3.2 years), and prior valvotomy/valvuloplasty (n = 13, 13.9 ± 3.2 years). CMR data included LV volumetric and mass indices, myocardial strain and aortic hemodynamics. BAV patients with no valvulopathy or isolated AS had similar LV parameters to controls excepting cardiac output (p < 0.05). AS + AR and post-surgical patients had abnormal LV volumetric and mass indices (p < 0.01). Post-surgical patients had decreased global longitudinal strain (p = 0.02); other subgroups had comparable strain to controls. Patients with valvulopathy demonstrated elevated velocity and wall shear stress (WSS) in the ascending aorta (AAo) and arch (p < 0.01), while those without valve dysfunction had only elevated AAo velocity (p = 0.03). Across the cohort, elevated AAo velocity and WSS correlated to higher LV mass (p < 0.01), and abnormal hemodynamics correlated to decreased strain rates (p < 0.045). Pediatric BAV patients demonstrate abnormalities in LV parameters as a function of valvular dysfunction, most significantly in children with AS + AR or prior valvotomy/valvuloplasty. Correlations between aortic hemodynamics, LV mass and strain suggest valvular dysfunction could drive LV remodeling. Multiparametric CMR assessment in pediatric BAV may help stratify risk for cardiac remodeling and dysfunction.

Evaluation of stimulus-effect relations in left ventricular growth using a simple multiscale model

Cardiac growth is the natural capability of the heart to change size in response to changes in blood flow demand of the growing body. Cardiac diseases can trigger the same process leading to an abnormal type of growth. Prediction of cardiac growth would be clinically valuable, but so far published models on cardiac growth differ with respect to the stimulus-effect relation and constraints used for maximum growth. In this study, we use a zero-dimensional, multiscale model of the left ventricle to evaluate cardiac growth in response to three valve diseases, aortic and mitral regurgitation along with aortic stenosis. We investigate how different combinations of stress- and strain-based stimuli affect growth in terms of cavity volume and wall volume and hemodynamic performance. All of our simulations are able to reach a converged state without any growth constraint, with the most promising results obtained while considering at least one stress-based stimulus. With this study, we demonstrate how a simple model of left ventricular mechanics can be used to have a first evaluation on a designed growth law.

The association of reduced global longitudinal strain with cancer therapy-related cardiac dysfunction among patients receiving cancer therapy

BACKGROUND

Cardiotoxicity is a leading cause of morbidity and mortality among patients receiving cancer therapy. The most commonly used definition is cancer therapy-related cardiac dysfunction (CTRCD) defined by a left ventricular ejection fraction reduction. Global longitudinal strain (GLS) has been implied to be superior in detecting early subclinical dysfunction.

OBJECTIVES

Evaluate the prevalence of reduced GLS and whether it is associated with CTRCD development among patients receiving cancer therapy.

METHODS

Data were collected as part of the Israel Cardio-Oncology Registry (ICOR), a prospective registry enrolling all adult patients receiving different types of cancer therapy, who were referred to the cardio-oncology clinic. Patients were divided into two groups-reduced GLS (> - 17%) vs. preserved GLS (≤ - 17%). Multivariable analyses were adjusted for a propensity score for baseline characteristics.

RESULTS

Among 291 consecutive patients, 48 (16%) patients were included in the reduced GLS group. Overall, 11 (5%) patients developed CTRCD at following echocardiogram evaluation. Patients with preserved GLS had a significantly lower risk for CTRCD development [odds ratio (OR) 0.11, 95% confidence interval (CI) 0.03-0.41, p = 0.001], with every 1-unit improvement of GLS the risk of CTRCD decreased by 16% (OR 0.84, 95%CI 0.73-0.95, p = 0.007). After adjustment for baseline characteristics, including cardiovascular risk factors and systolic function, preserved GLS remained significantly associated with a lower risk for CTRCD development (OR 0.11, 95%CI 0.02-0.64, p = 0.014), with every 1-unit improvement lowering the risk by 19% (OR 0.81, 95%CI 0.67-0.98, p = 0.032).

CONCLUSIONS

Reduced GLS is common among patients receiving cancer therapy and may identify patients at increased risk for CTRCD development.

Transcatheter aortic valve replacement for pure aortic valve regurgitation: "on-label" versus "off-label" use of TAVR devices

INTRODUCTION

Transcatheter aortic valve replacement (TAVR) has become the mainstay of treatment for aortic stenosis in patients with high surgical risk. Pure aortic regurgitation (PAR) is considered a relative contraindication for TAVR; however, TAVR is increasingly performed in PAR patients with unfavorable risk profile. Herein, we aim to summarize available data on TAVR for PAR with special emphasis on "on-label" versus "off-label" TAVR devices.

METHODS AND RESULTS

Pubmed was searched for studies of patients undergoing TAVR for PAR. Primary outcome was 30 day-mortality. Pooled estimated event rates were calculated. Twelve studies including a total of 640 patients were identified until December 2017. Among these, 208 (33%) patients were treated with devices with CE-mark approval for PAR ("on-label"; JenaValve and J valve). Overall, the procedural success rate was 89.9% (95% CI 81.1-96.1%; I² 80%). Major bleeding was reported in 6.4% (95% CI 2.9-10.8%; I² 48%). All-cause mortality at 30 days was 10.4% (95% CI 7.1-14.2%; I² 20%). Stroke occurred in 2.2% (95% CI 0.9-3.9%; I² 0%). A permanent pacemaker was required in 10.7% (95% CI 7.3-14.6%; I² 23%). At 30 days after TAVR, ≥ moderate AR post-interventional was observed in 11.5% (95% CI 2.9-23.6%; I² 90%). In the "on-label"-group, success rate was 93.0% (95% CI 85.9-98.1%; I² 52%). 30-day-mortality was 9.1% (95% CI 3.7-16.0%; I² 36%). More than trace AR was present in 2.8% (95% CI 0.1-7.6%; I² 0%). Compared to first-generation devices, second-generation devices were associated with significantly lower 30-day-mortality (r = - 0.10; p = 0.02), and significantly higher procedural success rates (r = 0.28; p < 0.001). Compared to other second-generation devices, the use of J valve or JenaValve was not associated with altered mortality (r = 0.04; p = 0.50), rates of > trace residual AR (r = - 0.05; p = 0.65) but with a significantly higher procedural success (r = 0.15; p = 0.042).

CONCLUSION

Based on this summary of available observational data TAVR for PAR is feasible and safe in patients deemed inoperable. First-generation TAVR devices are associated with inferior outcome and should be avoided. The "on-label" use of PAR-certified TAVR devices is associated with a significantly higher procedural success rate and might be favorable compared to other second-generation devices.

Test-retest reliability of new and conventional echocardiographic parameters of left ventricular systolic function

Background

Reliability of left ventricular function measurements depends on actual biological conditions, repeated registrations and their analyses.

Objective

To investigate test–retest reliability of speckle-tracking-derived strain measurements and its determinants compared to the conventional parameters, such as ejection fraction (EF), LV volumes and mitral annular plane systolic excursion (MAPSE).

Methods

In 30 patients with a wide range of left ventricular function (mean EF 46.4 ± 16.4%, range 14–73%), standard echo views were acquired independently in a blinded fashion by two different echocardiographers in immediate sequence and analyzed off-line by two independent readers, creating 4 data sets per patient. Test–retest reliability of studied parameters was calculated using the smallest detectable change (SDC) and a total, inter-acquisition and inter-reader intra-class correlation coefficient (ICC).

Results

The smallest detectable change normalized to the mean absolute value of the measured parameter (SDCrel) was lowest for MAPSE (10.7%). SDCrel for EF was similar to GLS (14.2 and 14.7%, respectively), while SDCrel for CS was much higher (35.6%). The intra-class correlation coefficient was excellent (> 0.9) for all measures of the left ventricular function. Intra-patient inter-acquisition reliability (ICCacq) was significantly better than inter-reader reliability (ICCread) (0.984 vs. 0.950, p = 0.03) only for EF, while no significant difference was observed for any other LV function parameter. Mean intra-subject standard deviations were significantly correlated to the mean values for CS and LV volumes, but not for the other studied parameters.

Conclusions

In a test–retest setting, both with normal and impaired left ventricular function, the smallest relative detectable change of EF, GLS and MAPSE was similar (11–15%), but was much higher for CS (35%). Surprisingly, reliability of GLS was not superior to that of EF. Acquisition and reader to a similar extent influenced the reliability of measurements of all left ventricular function measures except for ejection fraction, where the reliability was more dependent on the reader than on the acquisition.

Long-term effects of device-guided slow breathing in stable heart failure patients with reduced ejection fraction

Background

Slow breathing (SLOWB) alleviates symptoms of chronic heart failure (HF) but its long-term effects are unknown. We examined the acute and long-term impact of device-guided breathing on hemodynamics and prognostic parameters in HF patients with reduced ejection fraction (HFrEF).

Methods and results

Twenty-one patients with HFrEF (23.9 ± 5.8%, SD ± mean) on optimal medical therapy underwent blood pressure (BP), heart rate (HR), HR variability, 6-min walk test (6MWT), cardiopulmonary exercise testing (CPET), and echocardiography measurements before and 3 months after SLOWB home training (30 min daily). After 3 months, all patients were assigned to continue SLOWB (Group 1) or no-SLOWB (Group 2). All tests were repeated after 6 months. Acute SLOWB (18 ± 5 vs 8 ± 2 breaths/min, P < 0.001) had no influence on BP and HR but improved saturation (97 ± 2 vs 98 ± 2%, P = 0.01). Long-term SLOWB reduced office systolic BP (P < 0.001) but not central or ambulatory systolic BP. SLOWB reduced SDNN/RMSSD ratio (P < 0.05) after 3 months. One-way repeated measures of ANOVA revealed a significant increase in 6MWT and peak RER (respiratory exchange ratio) from baseline to 6-month follow-up in group 1 (P < 0.05) but not group 2 (P = 0.85 for 6MWT, P = 0.69 for RER). No significant changes in echocardiography were noted at follow-up. No HF worsening, rehospitalisation or death occurred in group 1 out to 6-month follow-up. Two hospitalizations for HF decompensation and two deaths ensued in group 2 between 3- and 6-month follow-up.

Conclusions

SLOWB training improves cardiorespiratory capacity and appears to slow the progression of HFrEF. Further long-term outcome studies are required to confirm the benefits of paced breathing in HFrEF.