Left Atrial Strain Has Superior Prognostic Value to Ventricular Function and Delayed-Enhancement in Dilated Cardiomyopathy

Left Atrial Markers in Diagnosing and Prognosticating Non-Ischemic Cardiomyopathies: Ready for Prime Time?

The left atrium (LA) is pivotal in cardiac hemodynamics, serving as a dynamic indicator of left ventricular (LV) compliance and diastolic function. The LA undergoes structural and functional adaptations in response to hemodynamic stress, infiltrative processes, myocardial injury, and arrhythmic triggers. Remodeling of the LA in response to these stressors directly impacts pulmonary circulation, eventually leading to pulmonary capillary involvement, pulmonary artery hypertension, and eventually right ventricular failure. LA dysfunction and fibrosis also contribute to the future risk of atrial arrhythmias and mitral regurgitation. The parameters of LA size and function are being recognized as robust markers for the progression of several cardiac pathologies as well as important tools for prognostication. In this article, we briefly describe the different modalities and markers used to evaluate LA pathology in patients with nonischemic cardiomyopathies (NICM). We then provide an overview of the studies that compared the association of the different LA parameters with disease severity and future prognosis. We also identify the gaps in knowledge before these LA parameters make a case for clinical adoption.

Incremental Prognostic Value of Left Atrial Strain in Patients With Suspected Myocarditis and Preserved Left Ventricular Ejection Fraction

BACKGROUND

Analysis of left atrial (LA) strain and left atrioventricular coupling index (LACI) have prognostic value in cardiovascular diseases. However, the prognostic value of LA strain and LACI in patients with suspected myocarditis and preserved left ventricular ejection fraction (LVEF) is unclear.

PURPOSE

To investigate the prognostic value of LA strain and LACI in patients with suspected myocarditis and preserved LVEF in comparison with conventional MRI outcome predictors.

STUDY TYPE

Retrospective.

POPULATION

One hundred sixty-five patients with clinically suspected myocarditis and preserved LVEF with available follow-up data.

FIELD STRENGTH/SEQUENCE

Steady-state free precession cine and phase-sensitive inversion recovery segmented gradient echo late gadolinium enhancement sequences at 3.0 T.

ASSESSMENT

Left ventricular (LV) and LA strain were evaluated using feature tracking. LACI was calculated as the ratio of LA and LV volumes at LV end-diastole. Patients were followed-up with the primary endpoint being major adverse cardiovascular events (MACE).

STATISTICAL TESTS

Independent-samples t-test and Mann-Whitney U test to compare patients with and without MACE, receiver operating characteristic (ROC) curve analysis to define high/low risk groups, Kaplan-Meier survival analysis and Cox proportional hazards regression to assess prognosis. A P value of <0.05 was considered statistically significant.

RESULTS

The associations of LV strain parameters (including global radial, circumferential, and longitudinal strain) and LACI with MACE were not significant (P = 0.511, 0.108, 0.148, and 0.847, respectively). An optimal LA conduit strain (Ԑe) cutoff value of 10.4% was identified to best classify patients into low- and high-risk groups. Only Ԑe was significantly associated with MACE in both univariable (hazards ratio [HR] 0.936, 95% confidence interval [CI] 0.884-0.991) and multivariable Cox survival analyses (HR 0.937, 95% CI 0.884-0.994).

DATA CONCLUSION

LA conduit strain has prognostic value in patients with suspected myocarditis and preserved LVEF, incremental to conventional MRI outcome predictors, whereas LACI was not associated with MACE occurrence.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 2.

Left atrial strain in non-ischemic dilated cardiomyopathy in sinus rhythm: Prognostic implications and interrelationship with left ventricular deformation

BACKGROUND

Left atrial deformation analysis may identify patients at higher risk of adverse events in the setting of non-ischemic dilated cardiomyopathy (NIDCM). The purpose was to determine the association between peak longitudinal (PALS) and contraction (PACS) LA strain in NIDCM, accounting for left ventricular global longitudinal strain (LV-GLS).

METHODS

Consecutive patients with NIDCM, sinus rhythm and LV ejection fraction (LVEF)<50 % were included. PALS, PACS and LV-GLS were obtained from echocardiography images. The composite outcome was a combination of hospitalization for heart failure, cardiovascular death, or ventricular arrhythmia. The association with the composite outcome was assessed using Cox regression and a classification and regression tree (CART) analysis was performed.

RESULTS

Among 347 patients included (median age 66 years old, median LVEF 35 %), median PALS and PACS values of 16 % and 9 %. After a median follow-up of 3.6 years, the composite outcome occurred in 70 (20.2 %) patients. PACS ≤8 % was associated with the composite outcome (adjusted HR = 2.73, 95 %CI 1.33-5.60), mostly by increasing the risk of heart failure admission. LV-GLS increased the risk of the composite outcome among patients with PACS>8 % (HR = 1.20, 95 %CI 1.07-1.35). PALS more strongly correlated with LV-GLS (Spearmans' rho = -0.71) than PACS (rho = -0.5). A decreased PALS/LV-GLS ratio was associated with higher rates of the composite outcome.

CONCLUSION

LA dysfunction is a major determinant of the composite outcome in NIDCM with LVEF <50 % and should be routinely assessed. PACS may perform better than PALS when combined with LV-GLS, probably due to lesser dependency from mitral annular motion.

Evaluating pulmonary stenosis and regurgitation impact on cardiac strain and strain rate in a porcine model via magnetic resonance feature tracking

BACKGROUND

Pulmonary stenosis (PS) is common in congenital heart disease and an integral finding in Tetralogy of Fallot (TOF). Pulmonary regurgitation (PR) is more commonly found following surgery in repaired TOF. We aimed to evaluate the haemodynamic effects of PS and PR on cardiac physiology in a porcine model using cardiac magnetic resonance-based feature tracking (CMR-FT) deformation imaging.

METHODS

CMR-FT was performed in 14 pigs before and 10-12 weeks after surgery. Surgery included either pulmonary artery banding to simulate PS (n = 7), or an incision to the pulmonary valve to simulate PR (n = 7). CMR-FT assessment included left and right ventricular global longitudinal (LV/RV GLS) and LV circumferential (GCS) strain and strain rates (SR) as well as left and right atrial reservoir/conduit/booster pump (LA/RA Es, Ee, Ea) strain and SR.

RESULTS

RV GLS was significantly reduced following PS compared to PR induction (PS -7.51 vs. PR -23.84, p < 0.001). RV GLS improved after induction of PR (before - 20.50 vs. after - 23.84, p = 0.018) as opposed to PS (before - 11.73 vs. after - 7.51, p = 0.128). Similarly, RA Es (PS 14.22 vs. PR 27.34, p = 0.017) and Ee (PS 8.65 vs. PR 20.51, p = 0.004) were decreased in PS compared to PR with detrimental impact of PS (Es before 23.20 vs. after 14.22, p = 0.018, Ee before 15.04 vs. after 8.65, p = 0.028) but not PR (Es before 31.65 vs. after 27.34, p = 0.176, Ee before 20.63 vs. after 20.51, p = 0.499).

CONCLUSIONS

In a porcine model of RV pressure vs. volume overload, increased after- but not preload shows detrimental impact on RV and RA physiology.

Unsupervised clustering of intraventricular hemodynamic forces for the phenotyping of left-ventricular function in non-ischemic left ventricular cardiomyopathy

BACKGROUND

Cardiac magnetic resonance (CMR) is essential for diagnosing cardiomyopathy, serving as the gold standard for assessing heart chamber volumes and tissue characterization. Hemodynamic forces (HDF) analysis, a novel approach using standard cine CMR images, estimates energy exchange between the left ventricular (LV) wall and blood. While prior research has focused on peak or mean longitudinal HDF values, this study aims to investigate whether unsupervised clustering of HDF curves can identify clinically significant patterns and stratify cardiovascular risk in non-ischemic LV cardiomyopathy (NILVC).

METHODS AND RESULTS

A retrospective cohort of 279 patients with NILVC who underwent cardiac CMR at Vall d'Hebron University Hospital (Barcelona) was examined. Unsupervised clustering of longitudinal and transversal HDF curves was performed using Dynamic Time Warping for dissimilarity measurement and the Partitioning Around Medoids algorithm. Outcomes were defined as a composite of cardiovascular mortality, heart failure hospitalization, and ventricular arrhythmias. Median age was 65[57.0;74.0] years, with 27.2% females and 35.5% showing late gadolinium enhancement (LGE). Unsupervised clustering identified three distinct clusters, delineating risk groups with worsening LA and LV function, indicating a stepwise increase in cardiovascular risk profile. Over a median follow-up of 40 months, 60 patients experienced the composite outcome. After adjusting for LGE, LVEF and LV size, clusters 2 and 3 demonstrated a significantly higher risk of adverse events (both p<0.05) compared to cluster 1.

CONCLUSION

Analyzing both longitudinal and transversal HDF throughout the cardiac cycle enables the identification of distinct phenotypes with prognostic value beyond ejection fraction and LGE in NILVC patients.

The prognostic value of left atrial strain and strain rate in predicting heart failure outcomes in patients with hypertrophic cardiomyopathy and a left ventricular ejection fraction of 50% or higher

AIM

Identifying high-risk hypertrophic cardiomyopathy (HCM) patients for heart failure (HF) is a challenge. Previous studies noted left atrial (LA) abnormalities in HCM patients, but the predictive value of LA strain and strain rate for HF in those with left ventricular ejection fraction (LVEF) ≥ 50% remains unclear. Our study aimed to explore if LA strain and strain rate predict HF-related outcomes in HCM patients with LVEF ≥ 50%.

MATERIALS AND METHODS

In this retrospective study, 284 patients aged 51 (range 40-62), 68% male, were studied. 34 experienced HF-related outcomes including death to HF, NYHA III-IV class progression, and HF worsening leading to hospitalization. LA strain and rate were analyzed using cardiac magnetic resonance (CMR) feature tracking technique. ROC curves, Kaplan-Meier curves, violin plot, LASSO analysis, forest plot, and Cox regression were used. The strength of the association was represented as HR∗, where HR∗ is defined as hazard ratio (HR) when the HR > 1 and as 1/HR when HR < 1.

RESULTS

After adjusting for the NYHA classification and the extent of LV-LGE, the booster strain (HR∗: 1.094; 95% CI: 0.845-0.989; p = 0.026) and booster strain rate (HR∗: 2.593; 95% CI: 1.369-4.910; p = 0.003) were significantly associated with HF-related events. Reservoir strain, conduit strain, and their respective strain rates did not emerge as independent predictors for HF-related outcomes.

CONCLUSION

LA booster strain and strain rate showed a stronger association with HF-related outcomes, highlighting significant functional changes in the LA. Identifying these parameters as key predictors underscores their importance in managing particularly in HCM patients with LVEF ≥ 50%.

Dapagliflozin Effects on Cardiac Deformation in Heart Failure and Secondary Clinical Outcome

BACKGROUND

Sodium-glucose cotransporter 2 inhibitors were shown to reduce morbidity and mortality in patients with heart failure.

OBJECTIVES

This study aims to assess potential effects of dapagliflozin in nondiabetic patients with heart failure with reduced ejection fraction (HFrEF) and heart failure with mildly reduced ejection fraction (HFmrEF) on cardiac function assessed by speckle tracking echocardiography (STE).

METHODS

This randomized, prospective, single-center, open-label trial compared consecutive nondiabetic outpatients with HFrEF or HFmrEF receiving dapagliflozin with patients treated with optimal medical therapy (OMT) except sodium-glucose cotransporter type 2 inhibitors. Primary endpoint was the presence of a significant modification of left ventricular global longitudinal strain, diastolic function (as peak atrial longitudinal strain) and right ventricular function by STE from baseline to 6 months. Cardiovascular events and parameters of congestion were assessed as safety-exploratory endpoints.

RESULTS

Overall, 88 patients (38% HFmrEF) were enrolled and randomized to start dapagliflozin on top of OMT (n = 44) or to continue with OMT (n = 44). All STE values improved in the dapagliflozin group after 6 months, whereas there was a nonsignificant improvement in OMT group. Moreover, when comparing the modification of STE parameters at follow-up in patients with HFrEF and HFmrEF, only the main treatment effect resulted statistically significant in both groups (P < 0.0001), indicating a significant difference between dapagliflozin and OMT.

CONCLUSIONS

This study provided randomized data on the beneficial effect of dapagliflozin in nondiabetic patients with HFrEF and HFmrEF in terms of myocardial performance measured by the most sensitive echocardiographic technique, ie, STE. This suggests its usefulness for left ventricular reverse remodeling and better quality of life in patients with HFrEF and HFmrEF. (Effects of Dapagliflozin on cardiac deformation and clinical outcomes in heart failure with reduced and mildly reduced ejection fraction [DAPA ECHO trial]; EudraCT number: 2021-005394-66).

MRI Assessment of Myocardial Deformation for Risk Stratification of Major Arrhythmic Events in Patients With Non-Ischemic Cardiomyopathy Eligible for Primary Prevention Implantable Cardioverter Defibrillators

BACKGROUND

Implantable cardioverter-defibrillator (ICD) intervention is an established prophylactic measure. Identifying high-benefit patients poses challenges.

PURPOSE

To assess the prognostic value of cardiac magnetic resonance imaging (MRI) parameters including myocardial deformation for risk stratification of ICD intervention in non-ischemic cardiomyopathy (NICM) while accounting for competing mortality risk.

STUDY TYPE

Retrospective and prospective.

POPULATION

One hundred and fifty-nine NICM patients eligible for primary ICD (117 male, 54 ± 13 years) and 49 control subjects (38 male, 53 ± 5 years).

FIELD STRENGTH/SEQUENCE

Balanced steady state free precession (bSSFP) and three-dimensional phase-sensitive inversion-recovery late gadolinium enhancement (LGE) sequences at 1.5 T or 3 T.

ASSESSMENT

Patients underwent MRI before ICD implantation and were followed up. Functional parameters, left ventricular global radial, circumferential and longitudinal strain, right ventricular free wall longitudinal strain (RV FWLS) and left atrial strain were measured (Circle, cvi42). LGE presence was assessed visually. The primary endpoint was appropriate ICD intervention. Models were developed to determine outcome, with and without accounting for competing risk (non-sudden cardiac death), and compared to a baseline model including LGE and clinical features.

STATISTICAL TESTS

Wilcoxon non-parametric test, Cox's proportional hazards regression, Fine-Gray competing risk model, and cumulative incidence functions. Harrell's c statistic was used for model selection. A P value <0.05 was considered statistically significant.

RESULTS

Follow-up duration was 1176 ± 960 days (median: 896). Twenty-six patients (16%) met the primary endpoint. RV FWLS demonstrated a significant difference between patients with and without events (-12.5% ± 5 vs. -16.4% ± 5.5). Univariable analyses showed LGE and RV FWLS were significantly associated with outcome (LGE: hazard ratio [HR] = 3.69, 95% CI = 1.28-10.62; RV FWLS: HR = 2.04, 95% CI = 1.30-3.22). RV FWLS significantly improved the prognostic value of baseline model and remained significant in multivariable analysis, accounting for competing risk (HR = 1.73, 95% CI = 1.12-2.66).

DATA CONCLUSIONS

In NICM, RV FWLS may provide additional predictive value for predicting appropriate ICD intervention.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 5.

Comparative prognostic importance of measures of left atrial structure and function in non-ischaemic dilated cardiomyopathy

AIMS

This study aimed to compare the association between measures of left atrial (LA) structure and function, derived from cardiovascular magnetic resonance (CMR), with cardiovascular death or non-fatal heart failure events in patients with non-ischaemic dilated cardiomyopathy (DCM).

METHODS AND RESULTS

CMR studies of 580 prospectively recruited patients with DCM in sinus rhythm [median age 54 (interquartile range 44-64) years, 61% men, median left ventricular ejection fraction 42% (30-51%)] were analysed for measures of LA structure [LA maximum volume index (LAVImax) and LA minimum volume index (LAVImin)] and function (LA emptying fraction, LA reservoir strain, LA conduit strain (LACS), and LA booster strain]. Over a median follow-up of 7.4 years, 103 patients (18%) met the primary endpoint. Apart from LACS, each measure of LA structure and function was associated with the primary endpoint after adjusting for other important prognostic variables. The addition of each LA metric to a baseline model containing the same important prognostic covariates improved model discrimination, with LAVImin providing the greatest improvement [C-statistic improvement: 0.702-0.738; χ2 test comparing likelihood ratio P < 0.0001; categorical net reclassification index: 0.210 (95% CI 0.023-0.392)]. Patients in the highest tercile of LAVImin had similar event rates to those with persistent atrial fibrillation. Measures of LA strain did not enhance model discrimination above LA volumetric measures.

CONCLUSION

Measures of LA structure and function offer important prognostic information in patients with DCM and enhance the prediction of adverse outcomes. LA strain was not incremental to volumetric analysis for risk prediction.

Risk Stratification in Nonischemic Dilated Cardiomyopathy Using CMR Imaging: A Systematic Review and Meta-Analysis

Importance

Accurate risk stratification of nonischemic dilated cardiomyopathy (NIDCM) remains challenging.

Objective

To evaluate the association of cardiac magnetic resonance (CMR) imaging-derived measurements with clinical outcomes in NIDCM.

Data Sources

MEDLINE, Embase, Cochrane Library, and Web of Science Core Collection databases were systematically searched for articles from January 2005 to April 2023.

Study Selection

Prospective and retrospective nonrandomized diagnostic studies reporting on the association between CMR imaging-derived measurements and adverse clinical outcomes in NIDCM were deemed eligible.

Data Extraction and Synthesis

Prespecified items related to patient population, CMR imaging measurements, and clinical outcomes were extracted at the study level by 2 independent reviewers. Random-effects models were fitted using restricted maximum likelihood estimation and the method of Hartung, Knapp, Sidik, and Jonkman.

Main Outcomes and Measures

All-cause mortality, cardiovascular mortality, arrhythmic events, heart failure events, and major adverse cardiac events (MACE).

Results

A total of 103 studies including 29 687 patients with NIDCM were analyzed. Late gadolinium enhancement (LGE) presence and extent (per 1%) were associated with higher all-cause mortality (hazard ratio [HR], 1.81 [95% CI, 1.60-2.04]; P < .001 and HR, 1.07 [95% CI, 1.02-1.12]; P = .02, respectively), cardiovascular mortality (HR, 2.43 [95% CI, 2.13-2.78]; P < .001 and HR, 1.15 [95% CI, 1.07-1.24]; P = .01), arrhythmic events (HR, 2.69 [95% CI, 2.20-3.30]; P < .001 and HR, 1.07 [95% CI, 1.03-1.12]; P = .004) and heart failure events (HR, 1.98 [95% CI, 1.73-2.27]; P < .001 and HR, 1.06 [95% CI, 1.01-1.10]; P = .02). Left ventricular ejection fraction (LVEF) (per 1%) was not associated with all-cause mortality (HR, 0.99 [95% CI, 0.97-1.02]; P = .47), cardiovascular mortality (HR, 0.97 [95% CI, 0.94-1.00]; P = .05), or arrhythmic outcomes (HR, 0.99 [95% CI, 0.97-1.01]; P = .34). Lower risks for heart failure events (HR, 0.97 [95% CI, 0.95-0.98]; P = .002) and MACE (HR, 0.98 [95% CI, 0.96-0.99]; P < .001) were observed with higher LVEF. Higher native T1 relaxation times (per 10 ms) were associated with arrhythmic events (HR, 1.07 [95% CI, 1.01-1.14]; P = .04) and MACE (HR, 1.06 [95% CI, 1.01-1.11]; P = .03). Global longitudinal strain (GLS) (per 1%) was not associated with heart failure events (HR, 1.06 [95% CI, 0.95-1.18]; P = .15) or MACE (HR, 1.03 [95% CI, 0.94-1.14]; P = .43). Limited data precluded definitive analysis for native T1 relaxation times, GLS, and extracellular volume fraction (ECV) with respect to mortality outcomes.

Conclusion

The presence and extent of LGE were associated with various adverse clinical outcomes, whereas LVEF was not significantly associated with mortality and arrhythmic end points in NIDCM. Risk stratification using native T1 relaxation times, extracellular volume fraction, and global longitudinal strain requires further evaluation.

Abnormal left atrial strain and left atrial stiffness index are associated with adverse outcomes in children with cardiomyopathies: a pilot study

Conventional diastolic dysfunction parameters seem to be imperfect when applied to the pediatric cardiomyopathy population. The aim of this pilot study was to search for novel echocardiographic parameters associated with adverse outcomes in children with the most common cardiomyopathies. Fifty-six patients with pediatric cardiomyopathies (28 with dilated, 21 with hypertrophic, 7 with left ventricular non-compaction cardiomyopathy) and 28 healthy subjects were included in the study. Left atrial reservoir (LASr), conduit (LAScd) and contraction (LASct) strain, left atrial stiffness index (LASI), as well as conventional diastolic dysfunction parameters were measured using echocardiography. Adverse outcomes were defined as heart failure (including heart transplant) and arrhythmic endpoints. Patients with adverse outcomes presented with significantly lower LASr (16.68% ± 8.64% vs. 33.97% ± 9.99%, p-value < 0.001), lower LAScd (- 10.37% ± 5.83% vs. - 25.50% ± 9.24%, p-value < 0.001) and higher values of LASI (0.69 [IQR 0.34; 1.11] vs. 0.21 [IQR 0.16; 0.31], p-value < 0.001). LASr < 20%, LAScd ≥ - 12%, and LASI ≥ 0.26 were all associated with reduced survival. LASr, LAScd and LASI seem to be promising parameters in predicting adverse outcomes in the most common pediatric cardiomyopathies. Left atrial strain parameters and LASI are helpful in differentiating healthy control subjects from children with hypertrophic and dilated cardiomyopathies.

Cardiac Magnetic Resonance Left Atrial Strain in the Prediction of Death, Ischemic Stroke, and Heart Failure

BACKGROUND

To determine the prognostic value of left atrial strain (LAS) using cardiac magnetic resonance for predicting death, heart failure, and ischemic stroke in patients with known or suspected coronary artery disease with preserved left ventricular systolic function and no prior history of ischemic stroke, heart failure, or atrial fibrillation.

METHODS AND RESULTS

This retrospective cohort analysis included patients referred for stress cardiac magnetic resonance or myocardial viability studies between September 2017 and December 2019. Patients with impaired left ventricular systolic function (<50%) or a history of atrial fibrillation, stroke, or heart failure were excluded. A multivariable Cox model assessed the prognostic value of LAS, with the primary outcomes being the composite outcomes of all-cause death, ischemic stroke, and heart failure. A total of 2030 participants were included in the study. The average LAS was 24.1±8.5%; 928 had LAS <23%, and 1102 had LAS ≥23%. The mean follow-up duration was 39.9±13.6 months. There were 49 deaths (2.4%), 32 ischemic strokes (1.6%), and 34 heart failure events (1.7%). Patients with LAS <23% were at greater risk for composite outcome, with an adjusted hazard ratio of 2.31 (95% CI, 1.50-3.55).

CONCLUSIONS

LAS by cardiac magnetic resonance has an independent and incremental prognostic value for death, ischemic stroke, and heart failure in patients with preserved left ventricular systolic function. This prognostic value is observed after adjusting for clinical and cardiac magnetic resonance parameters, including left ventricular systolic function, late gadolinium enhancement, and left atrial volume index.

Potential prognostic impact of left-ventricular global longitudinal strain in analysis of whole-heart myocardial mechanics in nonischemic dilated cardiomyopathy

Cardiac magnetic resonance (CMR) feature-tracking (FT) has an important diagnostic role in non-ischemic dilated cardiomyopathy (NIDCM). To date, the relationship between whole-heart myocardial mechanics by CMR and early primary outcomes in NIDCM has not been elucidated. patients with NIDCM were eligible for this study. CMR-FT was used to analyze whole-heart myocardial mechanics. The primary outcomes were a composite of heart failure (HF) death, heart transplantation (HT), and hospitalization for HF worsening (WHF) after 1-year since diagnosis. 98 patients were included. During a 1-year follow-up, a worse prognosis occurred in 32 patients (30 hospitalizations for WHF, 8 deaths, and 3 HT). The left ventricular (LV) global longitudinal systolic strain (GLS), left ventricular global circumferential strain (LV GCS), strains of right ventricle and both atria were significantly reduced in patients with events vs. those without (GLS - 8.0 ± 3.4 vs. - 12.1 ± 4.5, p < 0.001; GCS - 13.0 ± 6.4 vs. - 18.3 ± 7.1, p < 0.001; right ventricular (RV) GLS - 12.1 ± 4.9 vs. - 17.4 ± 6.4, p < 0.001; left atrial longitudinal strain 7.5 ± 3.8 vs. 15.1 ± 12.3, p < 0.001; right atrial longitudinal strain 11.0 ± 6.7 vs. 17.2 ± 8.0, p < 0.001). Left ventricular ejection fraction (LVEF) was significantly higher in patients with better prognosis (22.7 ± 8.7 vs. 33.56 ± 10.4, p < 0.001). Multivariate regression analysis revealed LV GLS as an independent predictor of a worse prognosis (OR 0.787, CI 95% 0.697-0.890, p < 0.001). reduction of LV GLS showed the strongest predictive value for the composite outcome of WHF, HT, and HF death.

Atrial and ventricular strain using cardiovascular magnetic resonance in the prediction of outcomes of pericarditis patients: a pilot study

OBJECTIVE

Our study aimed to explore with cardiovascular magnetic resonance (CMR) the impact of left atrial (LA) and left ventricular (LV) myocardial strain in patients with acute pericarditis and to investigate their possible prognostic significance in adverse outcomes.

METHOD

This retrospective study performed CMR scans in 36 consecutive patients with acute pericarditis (24 males, age 52 [23-52]). The primary endpoint was the combination of recurrent pericarditis, constrictive pericarditis, and surgery for pericardial diseases defined as pericardial events. Atrial and ventricular strain function were performed on conventional cine SSFP sequences.

RESULTS

After a median follow-up time of 16 months (interquartile range [13-24]), 12 patients with acute pericarditis reached the primary endpoint. In multivariable Cox regression analysis, LA reservoir and LA conduit strain parameters were all independent determinants of adverse pericardial diseases. Conversely, LV myocardial strain parameters did not remain an independent predictor of outcome. With receiving operating characteristics curve analysis, LA conduit and reservoir strain showed excellent predictive performance (area under the curve of 0.914 and 0.895, respectively) for outcome prediction at 12 months.

CONCLUSION

LA reservoir and conduit mechanisms on CMR are independently associated with a higher risk of adverse pericardial events. Including atrial strain parameters in the management of acute pericarditis may improve risk stratification.

CLINICAL RELEVANCE STATEMENT

Atrial strain could be a suitable non-invasive and non-contrast cardiovascular magnetic resonance parameter for predicting adverse pericardial complications in patients with acute pericarditis.

KEY POINTS

• Myocardial strain is a well-validated CMR parameter for risk stratification in cardiovascular diseases. • LA reservoir and conduit functions are significantly associated with adverse pericardial events. • Atrial strain may serve as an additional non-contrast CMR parameter for stratifying patients with acute pericarditis.

Myocardial Strain Imaging: Theory, Current Practice, and the Future

Myocardial strain imaging by echocardiography or cardiac magnetic resonance (CMR) is a powerful method to diagnose cardiac disease. Strain imaging provides measures of myocardial shortening, thickening, and lengthening and can be applied to any cardiac chamber. Left ventricular (LV) global longitudinal strain by speckle-tracking echocardiography is the most widely used clinical strain parameter. Several CMR-based modalities are available and are ready to be implemented clinically. Clinical applications of strain include global longitudinal strain as a more sensitive method than ejection fraction for diagnosing mild systolic dysfunction. This applies to patients suspected of having heart failure with normal LV ejection fraction, to early systolic dysfunction in valvular disease, and when monitoring myocardial function during cancer chemotherapy. Segmental LV strain maps provide diagnostic clues in specific cardiomyopathies, when evaluating LV dyssynchrony and ischemic dysfunction. Strain imaging is a promising modality to quantify right ventricular function. Left atrial strain may be used to evaluate LV diastolic function and filling pressure.

Interdependence between myocardial deformation and perfusion in patients with T2DM and HFpEF: a feature-tracking and stress perfusion CMR study

BACKGROUND

Patients with diabetes have an increased risk of developing heart failure with preserved ejection fraction (HFpEF). This study aimed to compare indices of myocardial deformation and perfusion between patients with type 2 diabetes mellitus (T2DM) with and without HFpEF and to investigate the relationship between myocardial strain and perfusion reserve.

METHODS

This study included 156 patients with T2DM without obstructive coronary artery disease (CAD) and 50 healthy volunteers who underwent cardiac magnetic resonance (CMR) examination at our center. Patients with T2DM were subdivided into the T2DM-HFpEF (n = 74) and the T2DM-non-HFpEF (n = 82) groups. The parameters of left ventricular (LV) and left atrial (LA) strain as well as stress myocardial perfusion were compared. The correlation between myocardial deformation and perfusion parameters was also assessed. Mediation analyses were used to evaluate the direct and indirect effects of T2DM on LA strain.

RESULTS

Patients with T2DM and HFpEF had reduced LV radial peak systolic strain rate (PSSR), LV circumferential peak diastolic strain rate (PDSR), LA reservoir strain, global myocardial perfusion reserve index (MPRI), and increased LA booster strain compared to patients with T2DM without HFpEF (all P < 0.05). Furthermore, LV longitudinal PSSR, LA reservoir, and LA conduit strain were notably impaired in patients with T2DM without HFpEF compared to controls (all P < 0.05), but LV torsion, LV radial PSSR, and LA booster strain compensated for these alterations (all P < 0.05). Multivariate linear regression analysis demonstrated that LA reservoir and LA booster strain were independently associated with global MPRI (β = 0.259, P < 0.001; β =  - 0.326, P < 0.001, respectively). Further, the difference in LA reservoir and LA booster strain between patients with T2DM with and without HFpEF was totally mediated by global MPRI. Global stress PI, LA booster, global rest PI, and global MPRI showed high accuracy in diagnosing HFpEF among patients with T2DM (areas under the curve [AUC]: 0.803, 0.790, 0.740, 0.740, respectively).

CONCLUSIONS

Patients with T2DM and HFpEF exhibited significant LV systolic and diastolic deformation, decreased LA reservoir strain, severe impairment of myocardial perfusion, and elevated LA booster strain that is a compensatory response in HFpEF. Global MPRI was identified as an independent influencing factor on LA reservoir and LA booster strain. The difference in LA reservoir and LA booster strain between patients with T2DM with and without HFpEF was totally mediated by global MPRI, suggesting a possible mechanistic link between microcirculation impairment and cardiac dysfunction in diabetes. Myocardial perfusion and LA strain may prove valuable for diagnosing and managing HFpEF in the future.

Myocardial hypertrophy: the differentiation of uremic, hypertensive, and hypertrophic cardiomyopathies by cardiac MRI

OBJECTIVES

To apply cardiac magnetic resonance imaging (CMR) for detailed myocardial characterization in uremic cardiomyopathy (UC), hypertensive cardiomyopathy (HTN), and hypertrophic cardiomyopathy (HCM) aiming to enrich the understanding of UC's etiology and further support the development of therapeutic strategies.

METHODS

A total of 152 patients (age: 49.2 ± 9.9 years; 65.8% male) underwent routine CMR from June 2016 to March 2023. Retrospectively, 53 patients with UC, 39 patients with HTN, 30 patients with HCM, and 30 healthy controls were included. Functional analysis, feature tracking of the left ventricle and left atrium, and myocardial T1, T2, and T2* mapping were performed. Statistical analysis included Pearson correlation and ROC analysis to define correlations and discriminators between groups.

RESULTS

UC patients demonstrated significantly higher native T1 (p < 0.001 for all) and T2 (p < 0.002 for all) values compared with the other three groups. UC patients revealed higher left atrial reservoir strain rate (p < 0.001 for all) and left atrial conduit strain rate (p < 0.001 for all) absolute values as compared with HTN and HCM patients. A significant correlation between T1 and T2 values in UC patients (r = 0.511, p < 0.001) was found. The combination of T1 values and strain parameters was the best discriminator between UC and HTN patients (AUC = 0.872, 95% CI: 0.801-0.943) and between UC and HCM patients (AUC = 0.840, 95% CI: 0.746-0.934).

CONCLUSION

UC reveals distinguishing tissue characteristics as evidenced by T1 and T2 mapping, as well as distinguishing functional strain parameters as compared with other hypertrophic phenotypes such as HTN and HCM.

CRITICAL RELEVANCE STATEMENT

The use of CMR imaging in UC patients offers incremental information to elucidate its complex etiology, contributing to ongoing discourse on effective treatment pathways.

KEY POINTS

This study investigated uremic, hypertensive, and hypertrophic cardiomyopathies using cardiac MRI. UC patients have higher T1 and T2 values and better preserved cardiac function. Combined strain and T1 values distinguish UC from other cardiomyopathies.

Papillary Muscle Delayed Hyperenhancement: Prevalence and Clinical Implications in a Large Population With Dilated Cardiomyopathy

Background

Papillary muscle-delayed hyperenhancement (papHE) at cardiac magnetic resonance indicates fibrotic or infiltrative processes. Contrary to myocardial HE, the prevalence and prognostic implications of papHE in patients with nonischemic dilated cardiomyopathy are unclear.

Objectives

The purpose of this study was to determine the prevalence of papHE and describe its association with adverse clinical outcomes.

Methods

This prospective cohort study included 528 patients who underwent late gadolinium enhancement cardiac magnetic resonance. The primary outcomes were all-cause mortality, sudden cardiac death, life-threatening arrhythmia, and hospitalization for heart failure. Patients were allocated into 4 categories: the first without papHE and without myocardial HE, the second with papHE, the third with myocardial HE, and the fourth with papHE and myocardial HE. The hazards of the primary outcomes for each category were compared using multivariable Cox regression.

Results

papHE was present in 131 patients (25%). The median follow-up duration was 6.1 years (IQR: 3.7-9.7 years). Isolated papHE and isolated myocardial HE were not significantly associated with any of the prespecified outcomes. Patients who had both myocardial HE and papHE were at an increased risk of all-cause mortality (HR: 2.33, 95% CI: 1.26-4.30), sudden cardiac death (HR: 3.77, 95% CI: 1.59-8.94), life-threatening arrhythmia (HR: 3.94, 95% CI: 1.34-11.58), and hospitalization for heart failure (HR: 2.97, 95% CI: 1.30-6.80).

Conclusions

The combined presence of myocardial and papHE was independently associated with adverse outcomes. Future studies should investigate if the incorporation of papHE and myocardial HE may improve clinical decision-making strategies to select dilated cardiomyopathy patients who would benefit the most from ICD implantation.

Prognostic Value of Left Atrial Volume and Late Gadolinium Enhancement on Cardiac Magnetic Resonance Imaging in Patients with Coronary Artery Disease and Severe Left Ventricular Dysfunction Underwent CABG

RATIONALE AND OBJECTIVES

This study aims to investigate whether the combination of Left atrial volume (LAV) and late gadolinium enhancement (LGE) is helpful in stratifying the risk in CABG patients with CAD with EF≤ 35%.

MATERIALS AND METHODS

We conducted a retrospective analysis involving 205 CAD patients with EF≤ 35% who underwent CABG. All patients underwent gadolinium-enhanced CMR before surgery. The CMR images were analyzed for LAV, biventricular function, LGE, and left ventricular myocardial strain. Primary endpoint events included all-cause mortality, revascularization, re-hospitalization due to myocardial infarction or heart failure, and stroke after CABG. Multivariable Cox analysis was performed to identify independent risk factors for adverse outcomes. Kaplan-Meier curve analysis with the log-rank test was employed to evaluate survival estimates.

RESULTS

A total of 55 patients reached the primary endpoints. Univariate Cox proportional hazard regression analysis showed that LAV index (LAVi), left ventricular EF (LVEF), right ventricular EF, LGE percent, and global longitudinal strain were significantly associated with the primary outcome (all P < 0.05). Multivariable analysis showed that LAVi (hazard ratio [HR] 1.05, [95% confidence interval (CI) 1.02-1.07], P < 0.001) and LGE percent (HR 1.10, [95% CI 1.06-1.15], P < 0.001) were independently associated with the primary outcome. Kaplan-Meier analysis indicated a significant increase in the risk of endpoint occurrence when patients exhibited LAVi≥ 51.0 mL/m2 and LGE≥ 11.6% (both P < 0.05).

CONCLUSION

For CAD patients with LVEF≤ 35%, the combination of LAVi and LGE percent demonstrated good predictive value for adverse events after CABG. CMR is a helpful tool to risk-stratify patients with severe left ventricular dysfunction undergoing CABG.

Reference ranges of computed tomography-derived strains in four cardiac chambers

Research on cardiovascular diseases using CT-derived strain is gaining momentum, yet there is a paucity of information regarding reference standard values beyond echocardiography, particularly in cardiac chambers other than the left ventricle (LV). We aimed to compile CT-derived strain values from the four cardiac chambers in healthy adults and assess the impact of age and sex on myocardial strains. This study included 101 (mean age: 55.2 ± 9.0 years, 55.4% men) consecutive healthy individuals who underwent multiphase cardiac CT. CT-derived cardiac strains, including LV global and segmental longitudinal, circumferential, and transverse strains, left atrial (LA), right atrial (RA), and right ventricle (RV) strains were measured by the commercially available software. Strain values were classified and compared by their age and sex. The normal range of CT-derived LV global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS) were -20.2 ± 2.7%, -27.9 ± 4.1%, and 49.4 ± 12.1%, respectively. For LA, reservoir strain, pump strain, and conduit strain were 28.6 ± 8.5%, 13.2 ± 6.4%, and 15.5 ± 8.6%, respectively. The GLS of RA and RV were 27.9 ± 10.9% and -22.0 ± 5.7%, respectively. The absolute values of GLS of RA and RV of women were higher than that in men (32.4 ± 11.4 vs. 24.3 ± 9.1 and -25.2 ± 4.7 vs. -19.4 ± 5.0, respectively; p<0.001, both). Measurement of CT-derived strain in four cardiac chambers is feasible. The reference ranges of CT strains in four cardiac chambers can be used for future studies of various cardiac diseases using the cardiac strains.

Cardiac magnetic resonance in advanced heart failure

Heart failure (HF) is a chronic and progressive disease that often progresses to an advanced stage where conventional therapy is insufficient to relieve patients' symptoms. Despite the availability of advanced therapies such as mechanical circulatory support or heart transplantation, the complexity of defining advanced HF, which requires multiple parameters and multimodality assessment, often leads to delays in referral to dedicated specialists with the result of a worsening prognosis. In this review, we aim to explore the role of cardiac magnetic resonance (CMR) in advanced HF by showing how CMR is useful at every step in managing these patients: from diagnosis to prognostic stratification, hemodynamic evaluation, follow-up and advanced therapies such as heart transplantation. The technical challenges of scanning advanced HF patients, which often require troubleshooting of intracardiac devices and dedicated scans, will be also discussed.

Left atrial structural and functional remodelling in Fabry disease and cardiac amyloidosis: A comparative analysis

BACKGROUND

Fabry disease (FD) and transthyretin cardiac amyloidosis (TTR CA) are cardiomyopathies with hypertrophic phenotype that share several features, including left atrial (LA) enlargement and dysfunction, but direct comparative data are lacking. Aim of the present study was to perform a comparative analysis of LA remodelling between the two diseases.

METHODS AND RESULTS

In this prospective study, a total of 114 patients (31 FD and 83 TTR CA) were included; all of them had left ventricular hypertrophy (LVH), defined as left ventricular (LV) wall thickness ≥ 12 mm. Despite similar degree of LVH, patients with TTR CA showed worse LV systolic and diastolic function. LA maximal volume index was not significantly different between the two groups (p = 0.084), while patients with TTR CA showed larger LA minimal volume index (p = 0.001). Moreover, all phases of LA mechanics were more impaired in the TTR CA group vs FD (reservoir: 6.9[4.2-15.5] vs 19.0[15.5-29.5], p < 0.001). After excluding patients with atrial fibrillation (AF), these differences remained clearly significant. In multivariable regression analyses, LA reservoir strain showed an independent correlation with TTR CA, controlling for demographic characteristics, AF and LV systolic and diastolic performance (p ≤ 0.001), whereas LV global longitudinal strain did not. Finally, among echocardiographic parameters, LA function demonstrated the highest accuracy in discriminating the two diseases.

CONCLUSIONS

TTR CA is characterized by a more advanced LA structural and functional remodelling in comparison to patients with FD and similar degree of LVH. The association between TTR CA and LA dysfunction remains consistent after adjustment for potential confounders.

Incremental diagnostic and prognostic utility of left atrial deformation in heart failure using speckle tracking echocardiography

Left atrium (LA) is a very important component of cardiovascular performance. The assessment of LA function has gathered the interest with expanding research supporting the utility as a biomarker for outcomes in heart failure (HF). Echocardiography is the main imaging modality which helps in a qualitative and quantitative assessment of the LA size and function. Recent advances in probe technology and software analysis have provided a better understanding of LA anatomy, physiology, pathology, and function. A variety of parameters have been defined as markers of LA function but there is no single parameter that best defines LA function. Speckle tracking echocardiography-derived analysis of LA deformation provides a window on all phases of LA function (reservoir, conduit, and booster pump). There is accumulative published data that supported the diagnostic and prognostic values of LA deformation integration during echo assessment of LA in HF. This review article summarized the clinical utility of LA deformation that may help in prediction, diagnosis, categorization, risk stratification, and guiding the proper selection of therapy in HF patients in daily practice.

Application of left atrial strain derived from cardiac magnetic resonance feature tracking to predict cardiovascular disease: A comprehensive review

The structural and functional changes of the left atrium (LA)are important for maintaining the filling of the left ventricle (LV), whether the hemodynamics is stable or not, and are valuable for evaluating LV diastolic dysfunction and grading the severity. Studies over the past decade have shown that LA structural alterations are linked to several cardiovascular disorders, and LA enlargement has been identified as a strong predictor of several cardiovascular diseases. However, LA structural or volumetric abnormalities are commonly seen in the advanced stages of disease and do not adequately represent functional changes throughout the cardiac cycle. In recent years, LA strain obtained using cardiac magnetic resonance feature tracking (CMR-FT)technology has been shown to provide early monitoring of LA tension damage while also comprehensively reflecting LA functional changes in three phases, providing deeper insights into cardiovascular disease risk, prognosis of cardiovascular disease, and evaluation of therapeutic efficacy. When compared to the ultrasound speckle tracking approach, the CMR-FT technique provides improved spatial resolution, repeatability, and reproducibility. We report a comprehensive review of the most recent studies on CMR-LA strain in the past five years, including normal reference values, early detection of disease, incremental diagnosis, improvement of risk stratification, assessment of the value of atrial-ventricular hemodynamics and coupled injury, major adverse cardiovascular events and prognostic value, as well as future research perspectives and current limitations, aiming at providing an objective reference for the further exploration of the value of the application of CMR-LA strain in various cardiac disorders.

Prognostic Utility of Left Atrial Strain From MRI Feature Tracking in Ischemic and Nonischemic Dilated Cardiomyopathy: A Multicenter Study

BACKGROUND. MRI-based prognostic evaluation in patients with dilated cardiomyopathy (DCM) has historically used markers of late gadolinium enhancement (LGE) and feature tracking (FT)-derived left ventricular global longitudinal strain (LVGLS). Early data indicate that FT-derived left atrial strain (LAS) parameters, including reservoir, conduit, and booster, may also have prognostic roles in such patients. OBJECTIVE. The purpose of our study was to evaluate the prognostic utility of LAS parameters, derived from MRI FT, in patients with ischemic or nonischemic DCM, including in comparison with the traditional parameters of LGE and LVGLS. METHODS. This retrospective study included 811 patients with ischemic or nonischemic DCM (median age, 60 years; 640 men, 171 women) who underwent cardiac MRI at any of five centers. FT-derived LAS parameters and LVGLS were measured using two- and four-chamber cine images. LGE percentage was quantified. Patients were assessed for a composite outcome of all-cause mortality or heart failure hospitalization. Multivariable Cox regression analyses including demographic characteristics, cardiovascular risk factors, medications used, and a wide range of cardiac MRI parameters were performed. Kaplan-Meier analyses with log-rank tests were also performed. RESULTS. A total of 419 patients experienced the composite outcome. Patients who did, versus those who did not, experience the composite outcome had larger LVGLS (-6.7% vs -8.3%, respectively; p < .001) as well as a smaller LAS reservoir (13.3% vs 19.3%, p < .001), LAS conduit (4.7% vs 8.0%, p < .001), and LAS booster (8.1% vs 10.3%, p < .001) but no significant difference in LGE (10.1% vs 11.3%, p = .51). In multivariable Cox regression analyses, significant independent predictors of the composite outcome included LAS reservoir (HR = 0.96, p < .001) and LAS conduit (HR = 0.91, p < .001). LAS booster and LGE were not significant independent predictors in the models. LVGLS was a significant independent predictor only in a model that initially included LAS booster but not the other LAS parameters. In Kaplan-Meier analysis, all three LAS parameters were significantly associated with the composite outcome (p < .001). CONCLUSION. In this multicenter study, LAS reservoir and LAS conduit were significant independent prognostic markers in patients with ischemic or nonischemic DCM, showing greater prognostic utility than the currently applied markers of LVGLS and LGE. CLINICAL IMPACT. FT-derived LAS analysis provides incremental prognostic information in patients with DCM.

Predictive value of a comprehensive atrial assessment with cardiac magnetic resonance in non-ischemic cardiomyopathy: keep it simple

Cardiac magnetic resonance (CMR) can provide a multi-parametric evaluation of left atrial (LA) size and function. A complete CMR-based LA assessment might improve the risk stratification of patients with non-ischemic dilated cardiomyopathy (DCM). We performed a comprehensive CMR-based evaluation of LA size and function, in order to assess the prognostic impact of specific LA parameters in DCM. Secondary analysis of a prospective registry (UHSM-CMR study, NCT02326324) including 648 consecutive patients with DCM and CMR evaluation of LA area and LA length. Of these, 456 had complete LA assessment covering reservoir, conduit and booster pump function and including LA reservoir strain evaluated with feature tracking. The heart failure (HF) endpoint included HF hospitalizations, HF death and heart transplant. The arrhythmic endpoint included ventricular arrhythmias (VA) (sustained or treated by implantable defibrillator) and sudden death (SD). At median follow-up of 23 months, 34 patients reached the HF endpoint; in a multivariable model including NYHA class and LVEF, LA length had incremental predictive value. LA length ≥ 69 mm was the best cut-off to predict HF events (adjusted HR 2.3, p = 0.03). Among the 456 patients with comprehensive LA assessment, only LA length was independently associated with the HF endpoint after adjusting for LVEF and NYHA class. By contrast, no LA parameter independently predicted the arrhythmic risk. In DCM patients, LA length is an independent predictor of HF events, showing stronger association than other more complex parameters of LA function. No atrial parameter predicts the risk of VA and SD.

Assessment of Right Atrial Function Measured with Cardiac MRI Feature Tracking for Predicting Outcomes in Patients with Dilated Cardiomyopathy

Background Right atrial (RA) function strain is increasingly acknowledged as an important predictor of adverse events in patients with diverse cardiovascular conditions. However, the prognostic value of RA strain in patients with dilated cardiomyopathy (DCM) remains uncertain. Purpose To evaluate the prognostic value of RA strain derived from cardiac MRI (CMR) feature tracking (FT) in patients with DCM. Materials and Methods This multicenter, retrospective study included consecutive adult patients with DCM who underwent CMR between June 2010 and May 2022. RA strain parameters were obtained using CMR FT. The primary end points were sudden or cardiac death or heart transplant. Cox regression analysis was used to determine the association of variables with outcomes. Incremental prognostic value was evaluated using C indexes and likelihood ratio tests. Results A total of 526 patients with DCM (mean age, 51 years ± 15 [SD]; 381 male) were included. During a median follow-up of 41 months, 79 patients with DCM reached the primary end points. At univariable analysis, RA conduit strain was associated with the primary end points (hazard ratio [HR], 0.82 [95% CI: 0.76, 0.87]; P < .001). In multivariable Cox analysis, RA conduit strain was an independent predictor for the primary end points (HR, 0.83 [95% CI: 0.77, 0.90]; P < .001). A model combining RA conduit strain with other clinical and conventional imaging risk factors (C statistic, 0.80; likelihood ratio, 92.54) showed improved discrimination and calibration for the primary end points compared with models with clinical variables (C statistic, 0.71; likelihood ratio, 37.12; both P < .001) or clinical and imaging variables (C statistic, 0.75; likelihood ratio, 64.69; both P < .001). Conclusion CMR FT-derived RA conduit strain was an independent predictor of adverse outcomes among patients with DCM, providing incremental prognostic value when combined in a model with clinical and conventional CMR risk factors. Published under a CC BY 4.0 license. Supplemental material is available for this article.

The Added Value of Advanced Echocardiography for the Morpho-Functional and Prognostic Evaluation of the Right Heart in Dilated Cardiomyopathy: Do Not Forget about the Right Atrium

(1) Introduction and Aims: Right ventricular (RV) remodeling significantly impacts the prognosis of dilated cardiomyopathy (DCM) patients, and right atrial (RA) size and function are still often neglected in DCM patients. Accordingly, our aims were to (i) evaluate right heart subclinical changes and (ii) the prognostic value of RA compared to left atrial (LA) size and function in patients with DCM by advanced echocardiography. (2) Materials and Methods: Sixty-eight patients with DCM (with a mean age of 60 years; 35 men) were evaluated by comprehensive transthoracic echocardiography, compared to 62 age- and sex-matched healthy controls (with a mean age of 61 years; 32 men), and followed up for 12.4 ± 5 months. (3) Results: DCM patients have RV and RA global longitudinal dysfunction by 2DSTE, higher RA minimum volumes and tricuspid annulus areas despite having normal RV volumes, ejection fractions, and RA maximum volumes by 3DE compared to the controls. The RA strain and RV strain are correlated with each other. The RA reservoir strain (with an AUC = 0.769) has an increased value for outcome prediction compared to that of the LA strain. (4) Conclusion: Patients with DCM have RV longitudinal dysfunction and decreased RA function, in the absence of clinical RV involvement or atrial arrhythmias, and the RA strain is associated with an increased risk of hospitalization and cardiac death.

Association between left atrial myopathy and sarcomere mutation in patients with hypertrophic cardiomyopathy: insights into left atrial strain by MRI feature tracking

OBJECTIVES

Left atrial (LA) myopathy, characterized by LA enlargement and mechanical dysfunction, is associated with worse prognosis in hypertrophic cardiomyopathy (HCM) while the impact of sarcomere mutation on LA myopathy remains unclear. We aimed to assess the association between LA myopathy and sarcomere mutation and to explore the incremental utility of LA strain in mutation prediction.

METHODS

A total of 105 consecutive HCM patients (mean age 47.8 ± 11.9 years, 71% male) who underwent HCM-related gene screening and cardiac MRI were retrospectively enrolled. LA volume, ejection fraction and strain indices in reservoir, conduit, and booster-pump phases were investigated respectively.

RESULTS

Fifty mutation-positive patients showed higher LA maximal volume index (59.4 ± 28.2 vs 43.8 ± 18.1 mL/m2, p = 0.001), lower reservoir (21.3 ± 7.9 vs 26.2 ± 6.6%, p < 0.001), and booster-pump strain (12.1 ± 5.4 vs 17.1 ± 5.0%, p < 0.001) but similar conduit strain (9.2 ± 4.5 vs 9.1 ± 4.5%, p = 0.909) compared with mutation-negative patients. In multivariate logistic regression, LA booster-pump strain was associated with sarcomere mutation (odds ratio = 0.86, 95% confidence interval: 0.77-0.96, p = 0.010) independent of maximal wall thickness, late gadolinium enhancement, and LA volume. Furthermore, LA booster-pump strain showed incremental value for mutation prediction added to Mayo II score (AUC 0.798 vs 0.709, p = 0.024).

CONCLUSIONS

In HCM, mutation-positive patients suffered worse LA enlargement and worse reservoir and booster-pump functions. LA booster-pump strain was a strong factor for sarcomere mutation prediction added to Mayo II score.

CLINICAL RELEVANCE STATEMENT

The independent association between sarcomere mutation and left atrial mechanical dysfunction provide new insights into the pathogenesis of atrial myopathy and is helpful to understand the adverse prognosis regarding atrial fibrillation and stroke in mutation-positive patients.

KEY POINTS

• In patients with hypertrophic cardiomyopathy, left atrial (LA) reservoir and booster-pump function, but not conduit function, were significantly impaired in mutation-positive patients compared with mutation-negative patients. • LA booster-pump strain measured by MRI-derived feature tracking is feasible to predict sarcomere mutation with high incremental value added to Mayo II score.

Prognostic value of left ventricular trabeculae fractal analysis in patients with dilated cardiomyopathy

BACKGROUND

The prognostic value of left ventricular (LV) myocardial trabecular complexity on cardiovascular magnetic resonance (CMR) in dilated cardiomyopathy (DCM) remains unknown. This study aimed to evaluate the prognostic value of LV myocardial trabecular complexity using fractal analysis in patients with DCM.

METHODS

Consecutive patients with DCM who underwent CMR between March 2017 and November 2021 at two hospitals were prospectively enrolled. The primary endpoints were defined as the combination of all-cause death and heart failure hospitalization. The events of cardiac death alone were defined as the secondary endpoints.LV trabeculae complexity was quantified by measuring the fractal dimension (FD) of the endocardial border based on fractal geometry on CMR. Cox proportional hazards regression and Kaplan-Meier survival analysis were used to examine the association between variables and outcomes. The incremental prognostic value of FD was assessed in nested models.

RESULTS

A total of 403 patients with DCM (49.31 ± 14.68 years, 69% male) were recruited. After a median follow-up of 43 months (interquartile range, 28-55 months), 87 and 24 patients reached the primary and secondary endpoints, respectively. Age, heart rate, New York Heart Association functional class >II, N-terminal pro-B-type natriuretic peptide, LV ejection fraction, LV end-diastolic volume index, LV end-systolic volume index, LV mass index, presence of late gadolinium enhancement, global FD, LV mean apical FD, and LV maximal apical FD were univariably associated with the outcomes (all P < 0.05). After multivariate adjustment, LV maximal apical FD remained a significant independent predictor of outcome [hazard ratio = 1.179 (1.116, 1.246), P < 0.001]. The addition of LV maximal apical FD in the nested models added incremental prognostic value to other common clinical and imaging risk factors (all <0.001; C-statistic: 0.84-0.88, P < 0.001).

CONCLUSION

LV maximal apical FD was an independent predictor of the adverse clinical outcomes in patients with DCM and provided incremental prognostic value over conventional clinical and imaging risk factors.

Left atrial conduit strain derived from cardiac magnetic resonance is an independent predictor of left ventricular reverse remodeling in patients with nonischemic cardiomyopathy

BACKGROUND

In some patients with nonischemic cardiomyopathy (NICM), left ventricular (LV) function improves with medical assistance, resulting in left ventricular reverse remodeling (LVRR). However, predictors of LVRR are not fully understood. The left atrium (LA) has been reported as a prognostic predictor in patients with heart failure (HF). The present study aimed to evaluate clinical predictors of LVRR related to LA function on cardiac magnetic resonance (CMR).

METHODS

A total of 103 patients with reduced left ventricular ejection fraction (LVEF) were enrolled in this retrospective study between September 2015 and July 2021. CMR parameters, including strain data, were measured in all patients. Echocardiographic data obtained approximately 2 years after enrollment were analyzed to assess LVRR.

RESULTS

LVRR occurred in 46 patients (44.7%) during follow-up. The value of LA conduit strain was higher in the LVRR group than in the non-LVRR group (6.6 [interquartile range (IQR): 5.6-9.3]% versus 5.0 [IQR: 3.0-6.2]%; p < 0.001). The multivariate logistic regression analysis showed that LA conduit strain was an independent predictor of LVRR (odds ratio [OR]: 1.216, 95% confidence interval [CI]: 1.050-1.408; p = 0.009). The area under the receiver operating characteristic (ROC) curve of the LA conduit strain was 0.746, and the cutoff value was 6.2%. The Kaplan‒Meier analysis revealed that the incidence of adverse cardiac events was significantly lower in patients with LA conduit strain > 6.2% compared to those with ⩽6.2%. (log-rank test, p = 0.019).

CONCLUSIONS

LA conduit strain derived from CMR is an independent predictor of LVRR in patients with NICM.

Incremental Diagnostic Value of Right Ventricular Strain Analysis in Arrhythmogenic Right Ventricular Cardiomyopathy

BACKGROUND

Strain analysis is a sensitive method for the assessment of ventricular structural or functional alterations. The authors aimed to determine whether right ventricular (RV) strain parameters can discriminate patients with revised Task Force Criteria-diagnosed arrhythmogenic RV cardiomyopathy (ARVC) incremental to the existing cardiovascular magnetic resonance (CMR) criteria, thus improving the diagnostic yield of CMR in ARVC.

METHODS AND RESULTS

A total of 74 patients with revised Task Force Criteria-diagnosed ARVC (37 borderline and 37 definite) and 37 controls were retrospectively enrolled for analysis. Using CMR feature tracking, RV global longitudinal (GLS), circumferential, and radial strain of all participants were evaluated. Compared with controls, the study patients demonstrated significantly impaired global biventricular strain in all 3 directions (all P<0.001). Receiver operating characteristic curve analysis indicated that RV GLS was the strongest discriminator among all RV strain parameters for the identification of patients with ARVC (area under the curve, 0.92). Using the Youden index, the authors determined RV GLS ≥-19.95% as the diagnostic criterion of ARVC. In patients diagnosed with borderline ARVC according to revised Task Force Criteria but with no or only minor CMR criteria, there were >50% presenting with impaired RV GLS. When both conventional criteria and RV GLS were considered together, this new diagnostic method demonstrated an overall diagnostic accuracy of 90%. The likelihood ratio test showed a significant incremental diagnostic value of RV GLS (P=0.02) over the existing CMR major criteria.

CONCLUSIONS

The current study showed an improved diagnostic accuracy when both RV GLS and the existing CMR criteria were considered together, especially for patients with borderline diagnosis, suggesting the incremental value of strain analysis to the initial assessment of ARVC.

Left atrial strain in adults after the arterial switch operation for transposition of the great arteries

BACKGROUND

No study has focused on left atrial (LA) function assessed by echocardiography in adult patients with simple D-TGA after arterial switch operation (ASO). We aimed to describe LA strain parameters in these patients.

METHODS

A prospective cohort study including 42 adult patients with simple D-TGA after ASO and 33 aged-matched controls. Phasic LA and LV global longitudinal strain (GLS) were obtained by transthoracic 2D-speckle tracking echocardiography (STE). Volumetric and functional analysis of LA and LV were also evaluated by 2D and 3D analysis. A multivariable model was performed to investigate the variables that best differentiate patients with D-TGA from healthy controls.

RESULTS

LA strain parameters in D-TGA patients were within the normal range described for healthy subjects. However, the three LA strain parameters (Reservoir, Conduit, and Contraction) were lower in patients (LASr: 31.13 ± 7.67 vs. 49.71 ± 8.38; LAS cd: -22.91 ± 5.69 vs. -34.55 ± 6.54; LASct: -8.14 ± 4.93 vs. -15.15 ± 6.07, p < .001 for all three comparisons). LA volumes were similar between patients and controls. LV-GLS remained significantly lower in the D-TGA group than in controls (-17.29 ± 2.68 vs. -21.98 ± 1.84, p < .001). D-TGA patients had evidence of worse LV ejection fraction measured by the Teichholz method (63.38 ± 8.23 vs. 69.28 ± 5.92, p = .001) and 3D analysis (57.97% ± 4.16 vs. 60.67 ± 3.39, p = .011) and diastolic dysfunction as compared to healthy controls. LV-GLS and conduit LAS were the variables best differentiating patients with D-TGA from healthy controls.

CONCLUSIONS

LA strain is impaired in young adults with simple D-TGA late after the ASO, probably in agreement with some degree of LV dysfunction previously described.

Left atrial strain analysis in the realm of pediatric cardiology: Advantages and implications

BACKGROUND

Left atrial (LA) strain analysis has emerged as a noninvasive technique for assessing LA function and early detection of myocardial deformation. Recently, its application has also shown promise in the pediatric population, spanning diverse cardiac conditions that demand accurate and sensitive diagnostic measures.

OBJECTIVE

This research article endeavors to explore the role of LA strain parameters and contribute to the growing body of knowledge in pediatric cardiology, paving the way for more effective and tailored approaches to patient care.

METHODS

A comprehensive literature review was conducted to gather evidence from studies using echocardiographic strain imaging techniques across pediatric populations.

RESULTS

LA strain parameters exhibited greater sensitivity than conventional atrial function indicators, with early detection of diastolic dysfunction and LA remodeling in pediatric cardiomyopathy, children with multisystem inflammatory syndrome, rheumatic heart disease, as well as childhood renal insufficiency and obesity offering prognostic relevance as potential markers in these pediatric subpopulations. However, there remains a paucity of evidence concerning pediatric mitral valve pathology, justifying further exploration.

CONCLUSION

LA strain analysis carries crucial clinical and prognostic implications in pediatric cardiac conditions, with reliable accuracy and sensitivity to early functional changes.

Incremental prognostic value of left atrial and biventricular feature tracking in dilated cardiomyopathy: a long-term study

BACKGROUND

Despite the use of cardiovascular magnetic resonance (CMR) feature tracking (FT) imaging to detect myocardial deformation, the optimal strain index in dilated cardiomyopathy (DCM) is unclear. This study aimed to determine whether atrial and biventricular strains can provide the greatest or joint incremental prognostic value in patients with DCM over a long follow-up period.

METHODS

Four hundred-twelve DCM patients were included retrospectively. Comprehensive clinical evaluation and imaging investigations were obtained, including measurements of CMR-FT derived left atrial (LA) reservoir, conduit, booster strain (εs, εe, εa); left ventricular (LV) and right ventricular (RV) global longitudinal, radial, circumferential strain (GLS, GRS, GCS). All patients were followed up for major adverse cardiac events (MACE) including all-cause mortality, heart transplantation, and implantable cardioverter defibrillator discharge. The predictors of MACE were examined with univariable and multivariable Cox regression analysis. Subsequently, nested Cox regression models were built to evaluate the incremental prognostic value of strain parameters. The incremental predictive power of strain parameters was assessed by Omnibus tests, and the model performance and discrimination were evaluated by Harrell C-index and integrated discrimination improvement (IDI) analysis. Patient survival was illustrated by Kaplan-Meier curves and differences were evaluated by log-rank test.

RESULTS

During a median follow-up of 5.0 years, MACE were identified in 149 (36%) patients. LAεe, LVGLS, and RVGLS were the most predictive strain parameters for MACE (AUC: 0.854, 0.733, 0.733, respectively). Cox regression models showed that the predictive value of LAεe was independent from and incremental to LVGLS, RVGLS, and baseline variables (HR 0.74, 95% CI 0.68-0.81, P < 0.001). In reclassification analysis, the addition of LAεe provided the best discrimination of the model (χ2 223.34, P < 0.001; C-index 0.833; IDI 0.090, P < 0.001) compared with LVGLS and RVGLS models. Moreover, LAεe with a cutoff of 5.3% further discriminated the survival probability in subgroups of patients with positive LGE or reduced LVEF (all log-rank P < 0.001).

CONCLUSION

LAεe provided the best prognostic value over biventricular strains and added incremental value to conventional clinical predictors for patients with DCM.

Echocardiographic Reference Ranges of Global Longitudinal Strain for All Cardiac Chambers Using Guideline-Directed Dedicated Views

BACKGROUND

Myocardial deformation by echocardiographic strain imaging is a key measurement in cardiology, providing valuable diagnostic and prognostic information. Reference ranges for strain should be established from large healthy populations with minimal methodologic biases and variability.

OBJECTIVES

The aim of this study was to establish echocardiographic reference ranges, including lower normal limits of global strains for all 4 cardiac chambers, by guideline-directed dedicated views from a large healthy population and to evaluate the influence of subject-specific characteristics on strain.

METHODS

In total, 1,329 healthy participants from HUNT4Echo, the echocardiographic substudy of the 4th wave of the Trøndelag Health Study, were included. Echocardiographic recordings specific for each chamber were optimized according to current recommendations. Two experienced sonographers recorded all echocardiograms using GE HealthCare Vivid E95 scanners. Analyses were performed by experts using GE HealthCare EchoPAC.

RESULTS

The reference ranges for left ventricular (LV) global longitudinal strain and right ventricular free-wall strain were -24% to -16% and -35% to -17%, respectively. Correspondingly, left atrial (LA) and right atrial (RA) reservoir strains were 17% to 49% and 17% to 59%. All strains showed lower absolute values with higher age, except for LA and RA contractile strains, which were higher. The feasibility for strain was overall good (LV 96%, right ventricular 83%, LA 94%, and RA 87%). All chamber-specific strains were associated with age, and LV strain was associated with sex.

CONCLUSIONS

Reference ranges of strain for all cardiac chambers were established based on guideline-directed chamber-specific recordings. Age and sex were the most important factors influencing reference ranges and should be considered when using strain echocardiography.

Prognostic Utility of Left Atrial Strain to Predict Thrombotic Events and Mortality in Amyloid Cardiomyopathy

BACKGROUND

There is currently no thromboembolic risk stratification tool for amyloid cardiomyopathy (ACM) and the current survival staging systems for ACM have only modest discriminatory ability.

OBJECTIVES

This study aims to evaluate the prognostic value of left atrial (LA) strain to predict incident thrombotic event (TE) and improve survival staging systems in ACM.

METHODS

The authors identified patients with light chain (AL) or transthyretin (ATTR) ACM and no history of atrial fibrillation (AF) at diagnosis. Three components of LA strain (reservoir, conduit, and contractile) were measured and their predictive value for TE and mortality was determined. In addition, the authors evaluated the incremental utility of adding LA strain to current prognostic staging systems.

RESULTS

The authors included 448 patients (50.2% AL; 49.8% ATTR) with median follow-up of 3.8 years. There were 64 (14.3%) TE cases, 103 (23%) AF cases, and 234 (52.2%) deaths. Notably, 75% of TEs occurred without preceding AF documented. LA strain reservoir and LA contractile strain significantly predicted both events: HRs for TE were 2.22 (95% CI: 1.27-3.85; P = 0.006) and 2.63 (95% CI: 1.25-5.00; P = 0.01) per SD decrease in LA strain reservoir and LA contractile strain, respectively. The respective HRs for mortality were 1.32 (95% CI: 1.09-1.59; P < 0.001) and 1.49 (95% CI: 1.22-1.75; P < 0.001). Also, LA strain reservoir and LA contractile strain significantly improved the C-statistics of the Mayo AL staging from 0.65 to 0.68 and 0.70, respectively (P ≤ 0.02); Mayo ATTR staging (0.73 to 0.79 and 0.80, respectively; P < 0.001); and Gillmore ATTR staging (0.70 to 0.79 and 0.80, respectively; P < 0.001).

CONCLUSIONS

LA strain identifies ACM patients with high thrombotic risk (independent of AF) and improves current ACM-specific survival staging.

Compressed sensing cine imaging with higher temporal resolution for analysis of left atrial strain and strain rate by cardiac magnetic resonance feature tracking

PURPOSE

Cardiac magnetic resonance (CMR) feature tracking (FT) is more widely used in the measurement of left atrial (LA) strain and strain rate (SR). However, in recent years, researchers have attempted to improve the low temporal resolution of CMR-FT to better capture the subtle deformations of the myocardium. The technique of compressed sensing (CS) has been applied clinically, reducing scan time while increasing temporal resolution. The purpose of this study was to explore the effect of the increased temporal resolution of CS cine sequences on the analysis of LA longitudinal strain and SR.

MATERIALS AND METHODS

Twenty-nine healthy subjects were included in the study. They underwent CMR with a reference steady-state free precession cine sequence of conventional temporal resolution (standard SSFP sequence), a cine sequence of higher temporal resolution (HT sequence), and an HT cine sequence with CS (CS HT sequence) (temporal resolution: 22.1-44.3/24.9-47.1 ms, 11.1-19.4 ms, and 8.3-19.4 ms, respectively). The standard SSFP sequence, HT sequence, and CS HT sequence were acquired in all subjects during the same scanning session. LA longitudinal strain and SR, reflecting LA reservoir, conduit, and contraction booster-pump function, were measured by CMR-FT and compared among the three sequences.

RESULTS

The measurements of LASR reservoir, conduit, and booster-pump were significantly higher on the HT and CS HT sequences than on the standard SSFP sequence. The standard SSFP sequence was correlated significantly with the HT and CS HT sequences in terms of LA strain and SR analysis, respectively. The LA strain and SR measurements also showed excellent agreement between the HT and CS HT sequences.

CONCLUSION

Higher temporal resolution led to significantly higher measured LASR values in CMR-FT. Furthermore, the addition of CS reduced scan time and did not affect LA longitudinal strain or SR analysis.

Dilated cardiomyopathy: causes, mechanisms, and current and future treatment approaches

Dilated cardiomyopathy is conventionally defined as the presence of left ventricular or biventricular dilatation or systolic dysfunction in the absence of abnormal loading conditions (eg, primary valve disease) or significant coronary artery disease sufficient to cause ventricular remodelling. This definition has been recognised as overly restrictive, as left ventricular hypokinesis without dilation could be the initial presentation of dilated cardiomyopathy. The causes of dilated cardiomyopathy comprise genetic (primary dilated cardiomyopathy) or acquired factors (secondary dilated cardiomyopathy). Acquired factors include infections, toxins, cancer treatment, endocrinopathies, pregnancy, tachyarrhythmias, and immune-mediated diseases. 5-15% of patients with acquired dilated cardiomyopathy harbour a likely pathogenic or pathogenic gene variant (ie, gene mutation). Therefore, the diagnostic tests and therapeutic approach should always consider both genetic and acquired factors. This Seminar will focus on the current multidimensional diagnostic and therapeutic approach and discuss the underlying pathophysiology that could drive future treatments aiming to repair or replace the existing gene mutation, or target the specific inflammatory, metabolic, or pro-fibrotic drivers of genetic or acquired dilated cardiomyopathy.

CMR-derived left ventricular intraventricular pressure gradients identify different patterns associated with prognosis in dilated cardiomyopathy

AIMS

Left ventricular (LV) blood flow is determined by intraventricular pressure gradients (IVPG). Changes in blood flow initiate remodelling and precede functional decline. Novel cardiac magnetic resonance (CMR) post-processing LV-IVPG analysis might provide a sensitive marker of LV function in dilated cardiomyopathy (DCM). Therefore, the aim of our study was to evaluate LV-IVPG patterns and their prognostic value in DCM.

METHODS AND RESULTS

LV-IVPGs between apex and base were measured on standard CMR cine images in DCM patients (n = 447) from the Maastricht Cardiomyopathy registry. Major adverse cardiovascular events, including heart failure hospitalisations, life-threatening arrhythmias, and sudden/cardiac death, occurred in 66 DCM patients (15%). A temporary LV-IVPG reversal during systolic-diastolic transition, leading to a prolonged transition period or slower filling, was present in 168 patients (38%). In 14%, this led to a reversal of blood flow, which predicted outcome corrected for univariable predictors [hazard ratio (HR) = 2.57, 95% confidence interval (1.01-6.51), P = 0.047]. In patients without pressure reversal (n = 279), impaired overall LV-IVPG [HR = 0.91 (0.83-0.99), P = 0.033], systolic ejection force [HR = 0.91 (0.86-0.96), P < 0.001], and E-wave decelerative force [HR = 0.83 (0.73-0.94), P = 0.003] predicted outcome, independent of known predictors (age, sex, New York Heart Association class ≥ 3, LV ejection fraction, late gadolinium enhancement, LV-longitudinal strain, left atrium (LA) volume-index, and LA-conduit strain).

CONCLUSION

Pressure reversal during systolic-diastolic transition was observed in one-third of DCM patients, and reversal of blood flow direction predicted worse outcome. In the absence of pressure reversal, lower systolic ejection force, E-wave decelerative force (end of passive LV filling), and overall LV-IVPG are powerful predictors of outcome, independent of clinical and imaging parameters.

Left Atrial Strain Derived From Cardiac Magnetic Resonance Imaging Can Predict Outcomes of Patients With Acute Myocarditis

OBJECTIVE

There is increasing recognition that left atrial (LA) strain can be a prognostic marker of various cardiac diseases. However, its prognostic value in acute myocarditis remains unclear. Therefore, this study aimed to evaluate whether cardiovascular magnetic resonance (CMR)-derived parameters of LA strain can predict outcomes in patients with acute myocarditis.

MATERIALS AND METHODS

We retrospectively analyzed the data of 47 consecutive patients (44.2 ± 18.3 years; 29 males) with acute myocarditis who underwent CMR in 13.5 ± 9.7 days (range, 0-31 days) of symptom onset. Various parameters, including feature-tracked CMR-derived LA strain, were measured using CMR. The composite endpoints included cardiac death, heart transplantation, implantable cardioverter-defibrillator or pacemaker implantation, rehospitalization following a cardiac event, atrial fibrillation, or embolic stroke. The Cox regression analysis was performed to identify associations between the variables derived from CMR and the composite endpoints.

RESULTS

After a median follow-up of 37 months, 20 of the 47 (42.6%) patients experienced the composite events. In the multivariable Cox regression analysis, LA reservoir and conduit strains were independent predictors of the composite endpoints, with an adjusted hazard ratio per 1% increase of 0.90 (95% confidence interval [CI], 0.84-0.96; P = 0.002) and 0.91 (95% CI, 0.84-0.98; P = 0.013), respectively.

CONCLUSION

LA reservoir and conduit strains derived from CMR are independent predictors of adverse clinical outcomes in patients with acute myocarditis.

Abnormal left atrial compliance is associated with a history of life-threatening arrhythmia in corrected Tetralogy of Fallot

Objectives

The objectives of this study were to examine left atrial (LA) function and compliance using two-dimensional (2D) strain analysis in adult patients with corrected Tetralogy of Fallot (c-ToF) and to investigate the relationships between LA function and patient characteristics, especially history of life-threatening arrhythmia (h-LTA).

Methods

Fifty-one c-ToF patients (34 males; age, 39 ± 15 years; h-LTA, n = 13) were included in this retrospective monocenter study. In addition to a 2D standard echocardiography examination, 2D strain analysis was performed to assess left ventricular (LV) and LA functions, including peak-positive LA strain (LAS-reservoir function) and LA compliance [defined as the ratio LAS/(E/Ea)].

Results

Patients with h-LTA were older and exhibited a longer QRS duration. LV ejection fraction, LAS and LA compliance were significantly lower in the group of patients with h-LTA. Indexed LA and RA volumes, RV end-diastolic area was significantly higher and RV fractional area change significantly lower in the h-LTA group. LA compliance was the best echocardiographic predictor for h-LTA (AUC: 0.839; p < 0.001). Moderate inverted correlations were found between LA compliance and age and QRS duration. Among the echocardiographic parameters, LA compliance was moderately inversely correlated with RV end-diastolic area (r = -0.40, p = 0.01).

Conclusion

We documented abnormal LAS and LA compliance values in adult c-ToF patients. Further study is needed to determine how best to incorporate LA strain, particularly LA compliance, into multiparametric predictive models for LTA in c-ToF patients.

Correlation between Heart rate recovery and Left Atrial phasic functions evaluated by 2D speckle-tracking Echocardiography after Acute Myocardial infarction

BACKGROUND

Heart rate recovery (HRR) in the exercise test is the index of cardiac autonomic system function and sympathovagal balance impaired in patients with myocardial infarction (MI). An instance is left atrial (LA) phasic function, which is impaired in such patients. In this study, we investigated the role of HRR in predicting LA phasic functions in patients with MI.

METHODS

The present study recruited 144 consecutive patients with ST-elevation MI. A symptom-limited exercise test was performed about 5 weeks after MI, with echocardiography conducted just before the exercise test. The patients were divided into abnormal and normal HRR at 60 s (HRR60) and again into abnormal and normal HRR at 120 s (HRR120) after the exercise test. LA phasic functions, evaluated by 2D speckle-tracking echocardiography, were compared between the 2 groups.

RESULTS

Patients with abnormal HRR120 had lower LA strain values and strain rates during the reservoir, conduit, and contraction phases, while those with abnormal HRR60 had lower LA strain values and strain rates during the reservoir and conduit phases. The differences were lost after adjustments for possible confounders, except for LA strain and strain rate during the conduit phase, in patients with abnormal HRR120.

CONCLUSIONS

Abnormal HRR120 in the exercise test can independently predict decreased LA conduit function in patients with ST-elevation MI.

Predictive value of left atrial strain analysis in adverse clinical events in patients with hypertrophic cardiomyopathy: a CMR study

BACKGROUND

A subset of patients with hypertrophic cardiomyopathy (HCM) will experience adverse clinical events such as heart failure (HF), cardiovascular death, and new-onset atrial fibrillation (AF). Current risk stratification methods are imperfect and limit the identification of patients at high risk for HCM. This study aimed to evaluate the role of cardiac magnetic resonance (CMR)-derived left atrial strain parameters in the occurrence of adverse clinical events in patients with HCM.

METHODS

Left atrial (LA) structural, functional, and strain parameters were evaluated in 99 patients with HCM and compared with 89 age-, sex-, and BMI-matched control subjects. LA strain parameters were derived from CMR two- and four-chamber cine images by a semiautomatic method. LA strain parameters include global longitudinal strain (GLS) and global circumferential strain (GCS). The LA GLS includes reservoir strain (GLS reservoir), conduit strain (GLS conduit), and booster strain (GLS booster). Three LA GLS strain rate (SR) parameters were derived: SR reservoir, SR conduit, and SR booster. The primary endpoint was set as a composite of adverse clinical events, including SCD, new-onset or worsening to hospitalized HF, new-onset AF, thromboembolic events, and fatal ventricular arrhythmias.

RESULTS

LA GLS, GLS SR and GCS were impaired in HCM patients compared to control subjects (all p < 0.001). After a mean follow-up of 37.94 ± 23.69 months, 18 HCM patients reached the primary endpoint. LA GLS, GLS SR, and GCS were significantly lower in HCM patients with adverse clinical events than in those without adverse clinical events (all p < 0.05). In stepwise multiple Cox regression analysis, LV SV, LA diameter, pre-contraction LAV (LAV pre-ac), passive LA ejection fraction (EF), and LA GLS booster were all independent determinants of adverse clinical events. LA GLS booster ≤ 8.9% was the strongest determinant (HR = 8.9 [95%CI (1.951, 40.933)], p = 0.005). Finally, LA GLS booster provided predictive adverse clinical events value (AUC = 0.86 [95%CI 0.77-0.98]) that exceeded traditional outcome predictors.

CONCLUSION

LA strain assessment, a measure of LA function, provides additional predictive information for established predictors of HCM patients. LA GLS booster was independently associated with adverse clinical events in patients with HCM.