Cardiac Magnetic Resonance Feature Tracking Research Articles

Left atrial morpho-functional changes in hypertrophic cardiomyopathy and Fabry disease: a CMR-feature tracking study

Abstract Funding Acknowledgements Type of funding sources: None. Background Left ventricular (LV) diastolic dysfunction (DD) is a hallmark of hypertrophic cardiomyopathy (HCM) and its phenocopies, such as Fabry disease (FD). Together with left atrial (LA) size, LA function is emerging as a sensitive marker of the adaptive changes to backward transmission of LV cardiac filling pressure, thus implementing DD assessment. Additionally, both HCM and FD are characterized by a primitive atrial myopathy, but LA morpho-functional changes in HCM and FD have never been directly compared. More recently, LA strain by Cardiovascular Magnetic Resonance Feature Tracking (CMR-FT) has been demonstrated to be a feasible and reproducible tool to explore LA function. Purpose To compare LA morpho-functional changes in HCM and FD and to explore their correlation with tissue alterations. Methods 15 HCM and 15 sex-, age- and LV mass index-matched FD patients underwent CMR (Magnetom Aera 1.5T, Siemens) and Doppler Echocardiography for LV diastolic function assessment (E/e’ and DD grading from 0 to 3). LA phasic function was evaluated by CMR-FT strain (Qstrain Medis). The software output included passive (εe, conduit function), active (εa, booster pump function) and total strain (εs, reservoir function), along with LA volumes and ejection fraction (EF). Late gadolinium enhancement (LGE) was quantified as a percentage of LV mass using the standard deviations (SDs) method (≥ 5 SDs). Interstitial fibrosis was assessed by extracellular volume (ECV) quantification in remote myocardium. All patients were in sinus rhythm. Results In the HCM group, the proportion of patients with DD grade 2-3 was only slightly higher than in FD (p 0.26). Accordingly, no significant difference was found in E/e’ value (p 0.78). Compared to FD, HCM patients showed more severe LA morpho-functional changes, including larger LA end-systolic volume (ESV) (113 ± 35 vs 84 ± 23 ml), lower LA EF (37 ± 7 vs 44 ± 9 %) and a greater reduction of εs (-20 ± 5 vs -25 ± 6 %) and εa (-10 ± 4 vs -15 ± 4 %) (all p < 0.05). LV size and function and the burden of fibrosis (LGE quantification and ECV) were comparable between the two groups. Interestingly, in HCM population, unlike in FD, LA morpho-functional measurements significantly correlated with tissue characterization parameters (LA ESV with LGE, r 0.56, p 0.03; εs and εa with ECV, r -0.51, p 0.05 and r -0.59, p 0.02, respectively). Conclusions LA morpho-functional alterations are much more severe in HCM compared to FD with similar degree of LV hypertrophy. A more severe atrial myopathy or different mechanisms of atrial damage in the two cardiomyopathies may explain these findings. LA CMR-FT analysis may represent a sensitive tool to discriminate between HCM and FD, although larger studies are needed to confirm this finding and the possible correlation with the occurrence of atrial arrhythmias and thromboembolic risk.

Diastolic function assessed my CMR feature tracking is a predictor for outcomes in patients with suspected myocarditis and preserved left ventricular ejection fraction

Abstract Funding Acknowledgements Type of funding sources: None. Diastolic function assessed my CMR feature tracking is a predictor for outcomes in patients with suspected myocarditis and preserved left ventricular ejection fraction Background Impairment of left ventricular (LV) systolic function was reported to be a valuable predictor for outcomes in patients with myocarditis. However, in patients with myocarditis and preserved LV systolic function, prediction of outcomes remains challenging. So far, minimal data exists about the prognostic role of diastolic function, as assessed by cardiac magnetic resonance imaging (CMR) in the clinical setting of suspected myocarditis. Purpose To determine the predictive value of LV diastolic function in patients with suspected myocarditis and preserved LV ejection fraction (LVEF). Methods In patients referred for CMR with clinically suspected myocarditis and LVEF≥50%, diastolic function was assessed by CMR feature tracking (FT). The primary endpoint was defined as a composite of major adverse cardiovascular events (MACE) including hospitalization for heart failure, recurrent myocarditis, sustained ventricular tachycardia and all-cause death. Results Of 381 patients included with clinically suspected myocarditis (216, 56.7% male, mean age 45.7 ± 16.4 years) late gadolinium enhancement (LGE) was present in 124 (32.4 %) of patients (mean LGE extent 4.9 ± 5.0 g). MACE occurred in 25 (6.6%) individuals at a median follow-up time of 4.5 years. In a univariate cox-regression model, radial, circumferential and longitudinal early diastolic strain rate (EDSR) and circumferential late diastolic strain rate were significantly associated with MACE. After adjustment for age, gender and extent of LGE, radial EDSR remained an independent predictor for MACE (HR = 2.26, 95% CI 1.06 to 4.8; p = 0.034). Conclusion Diastolic strain rate, as assessed by CMR-FT, can be useful in the prediction of outcomes in patients with myocarditis and preserved LVEF.

CMR feature tracking cloud assess right ventricular functional reserve with pulmonary arterial hypertension

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): JSPS KAKENHI, Grant-in-Aid for Early-Career Scientists. Background Pulmonary arterial hypertension (PAH) remains a fatal disorder characterized by elevated pulmonary arterial pressure. Survival of the patients with PAH is determined from right ventricular (RV) function. CMR has become an attractive modality for following up and providing prognosis in such patients, and CMR feature tracking has been used as a newer useful parameter to assess RV function. However, it has not yet been determined whether CMR feature tracking can assess RV functional reserve in patients with PAH. Purpose We investigated whether CMR feature tracking can estimate RV functional reserve using a rat model with PAH. Methods Rats were received injections with monocrotaline (MCT-rats, n = 19) or solvent (Ctr-rats, n = 5). Four weeks after the injections, we performed CMR on 7-T MRI scanner and imaged retrospective ECG-gated cine MR (16 phases/beat). RV ejection fraction (RVEF) and RV strain were analyzed before and after addition of 0.5∼3 nmol endothelin-1 (ET-1). After the measurements, we dissected trabeculae (length = 1.45 ± 0.07 mm, width = 334 ± 27 µm, thickness = 114 ± 6 µm) from the RVs of rat hearts. Trabeculae were electrically stimulated with 2-s intervals at extracellular Ca2+ of 0.7 and 2.0 mmol/L (24°C). Force and maximum dF/dt (dF/dtmax) were then measured using a silicon strain gauge in the absence and presence of 0.1 µM ET-1. Results MCT-rats showed higher systolic RV pressure (RVP), lower RVEF, and lower RV global longitudinal strain (RVGLS) in CMR imaging and showed lower developed force and lower dF/dtmax in their trabeculae. Correlation between RVGLS and dF/dtmax was higher (r = 0.53, p < 0.05) than that between RVEF and dF/dtmax (r = 0.24). In 5 MCT-rats with preserved RVEF (>50%), RVGLS had already been reduced, suggesting that RVGLS is reduced earlier than RVEF. ET-1 increased developed force and dF/dtmax in trabeculae from MCT-rats (12.2 ± 5.7 to 17.4 ± 3.1 mN/mm2 and 0.08 ± 0.03 to 0.14 ± 0.06 mN/mm2/sec, respectively, n = 6), and ET-1 also increased RVP in MCT-rats and Ctr-rats (49.0 ± 19.3 to 59.7 ± 16.8 mmHg in MCT-rats, n = 6, 17.3 ± 7.5 to 20.4 ± 7.8 mmHg in Ctr-rats, n = 2). According to RV global circumferential strain (RVGCS) and RVEF, we could divide MCT-rats into three groups as follows: MCT-rats with reduced-RVGCS (> -20%)/preserved-RVEF (> 50%), MCT-rats with increased-RVGCS (< -30%)/preserved-RVEF and MCT-rats with reduced-RVGCS/reduced-RVEF. ET-1 reduced RVGCS in MCT-rats with reduced-RVGCS/preserved-RVEF, while ET-1 did not change RVGCS in MCT-rats with increased-RVGCS/preserved-RVEF. MCT-rats with reduced-RVGCS/reduced-RVEF died after injection of ET-1. In Ctr-rats, ET-1 did not change RVGCS and RVEF. These results suggest that RVGCS can be useful to assess RV functional reserve. Conclusion CMR feature tracking can estimate RV functional reserve earlier and more accurately than RVEF in rats with PAH. RV strain may become an important parameter to assess RV functional reserve in patients with PAH.

Feature tracking cardiovascular magnetic resonance in asymptomatic patients with extracardiac sarcoidosis

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Regional Development Fund - Project ENOCH (No. CZ.02.1.01/0.0/0.0/16_019/0000868) and the Specific University Research (MUNI/A/1685/2020) provided by the Ministry of Education, Youth and Sports of the Czech Republic (MEYS CR) in the year 2020. Introduction Sarcoidosis is a systemic granulomatous disease affecting many organs including heart. Myocardial strain analysis could potentially detect early stadia of cardiac dysfunction in sarcoidosis patients. Purpose The study aims to assess use cardiac magnetic resonance (CMR) strain analysis using feature tracking (FT) in the detection of early cardiac involvement in asymptomatic patients with sarcoidosis. Methods One hundred thirteen CMR studies of patients with extracardiac sarcoidosis without pre-existing known cardiovascular disease were included into the study and analysed using FT and compared to 22 age and gender matched controls. Global longitudinal strain (GLS), global circumferential strain (GCS) and global radial strain (GRS) of left ventricle (LV) were measured. Results The sarcoidosis patients did not significantly differ from controls in basic demographic data and had normal global and regional systolic LV function – LV ejection fraction (EF) 66 ± 7% vs 65 ± 5% in controls (p = NS). No statistically significant differences were found in all strain parameters between patients and controls: GLS (-13.9 ± 3.1 vs. -14.2 ± 2.5), GCS (-23.4 ± 4.0 vs. -22.2 ± 2.9) and GRS (53.4 ± 13.5 vs. 51.2 ± 13.6%) (p = NS). Conclusion Asymptomatic patients with extracardiac sarcoidosis had normal myocardial deformation measured by CMR-FT derived global strain.

Prognostic implications of left ventricular torsion by feature-tracking cardiac magnetic resonance in patients with ST-elevation myocardial infarction

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): the National Key Research and Development Program of China OnBehalf Renji Hospital Affiliated to Medical College of Shanghai Jiaotong University Background The prognostic implications of left ventricular (LV) torsion on the long-term prognosis of patients with acute ST-elevation myocardial infarction (STEMI) is not clear. Methods We analyzed Cardiac Magnetic Resonance (CMR) images and followed up 420 first STEMI patients from the EARLY Assessment of MYOcardial Tissue Characteristics by CMR in STEMI (EARLY-MYO-CMR) registry (NCT03768453). These patients received timely primary percutaneous coronary intervention (PCI) within 12h and CMR examination within 1 week (median,5 days; range, 2-7 days) after infarction. Besides, CMR images of 40 normal people were enrolled as the control group. LV torsion, torsion rate and other conventional CMR indexes were measured. Ultrasound cardiogram examinations were performed in the acute phase and 1 year post-STEMI to assess LV remodeling (≥ 20% increase in LV end-diastolic volume). Primary end point was composite major adverse cardiac and cerebrovascular events (MACCEs) including cardiovascular death, re-infarction, re-hospitalization for heart failure and stroke. Secondary end points were the formation of LV aneurysm/thrombus in hospital as well as LV remodeling at 1 year post-STEMI. Results During follow-up (median: 52 months, inter-quartile range: 29–78 months), 80 patients developed MACCEs. Compared with normal people, patients with STEMI had more decreased LV torsion (P < 0.001) and torsion rate (P = 0.033). Patients who experienced MACCEs had more impaired LV torsion (P < 0.001) and torsion rate (P < 0.001) than those who didn’t. LV torsion ≤ 0.876 deg/cm in the acute phase of STEMI was an independent predictive factor of MACCE (P = 0.001) and LV remodeling (P = 0.001). Patients with impaired LV torsion were more likely to experience MACCEs (P < 0.001). The impairment of LV torsion was also associated with the higher incidence of LV aneurysm (P < 0.001) and thrombus (P = 0.006). The addition of LV torsion to a risk model comprising LV ejection fraction (LVEF), infarct size (IS), and microvascular obstruction (MVO) led to a net reclassification improvement (continuous NRI 0.499 [95% CI, 0.261–0.737]; P < 0.001). Hypertension (P = 0.047), tobacco use (P = 0.005), worse TIMI flow post-PCI (P < 0.001), more extensive IS (P < 0.001) / MVO size (P = 0.002) were associated with the impairment of LV torsion. Conclusions Compared with normal people, patients with STEMI had more decreased LV torsion and torsion rate. LV torsion ≤ 0.876 deg/cm in the acute phase was an independent predictive factor of MACCE and LV remodeling. The addition of LV torsion to a risk model comprising LVEF, LV-IS and LV-MVO significantly improved risk stratification of patients with STEMI .

Prognostic implications of peak early diastolic strain rate (PEDSR) by feature-tracking cardiac magnetic resonance in patients with st-elevation myocardial infarction

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): the National Key Research and Development Program of China OnBehalf Renji Hospital Affiliated to Medical College of Shanghai Jiaotong University Background：The prognostic value of Peak Early Diastolic Strain Rate (PEDSR) measured by Cardiac Magnetic Resonance (CMR) in ST-Elevation Myocardial Infarction (STEMI) is not clear. Methods：420 first-STEMI patients from the EARLY Assessment of MYOcardial Tissue Characteristics by CMR in STEMI (EARLY-MYO-CMR) registry (NCT03768453) and 40 normal people were enrolled and followed up. The patients received timely percutaneous coronary intervention (PCI) within 12h and CMR within 1 week (median,5 days; range, 2-7 days) after infarction. LV circumferential, radial, longitudinal PEDSR and other routine CMR parameters were measured. Clinical end point was a composite major adverse cardiovascular events (MACEs) including cardiovascular death, re-infarction and re-hospitalization for heart failure. Results：During follow-up (median: 52 months, inter-quartile range: 29–78 months), 73 (17.4%) patients experienced a MACE event. Compared with normal people, STEMI patients had lower PEDSR (circumf. PEDSR 0.77 vs. 1.27%/s, P < 0.001). Patients who developed MACEs also had lower PEDSR than patients who didn’t (circumf. PEDSR 0.64 vs. 0.78%/s, P < 0.001). Circumf. PEDSR can significantly predict MACEs with an AUC of 0.659 (95%CI 0.587-0.731, P < 0.001) which is not inferior to LVEF (0.659 vs. 0.651, P = 0.843), LVIS (0.659 vs. 0.661, P = 0.678) and LVMVO (0.659 vs. 0.666, P = 0.600). Circumf. PEDSR ≤ 0.665%/s is the independent predictive factor of MACEs in clinical (HR 2.099 [95%CI 1.273-3.461], P = 0.004) and CMR models (HR 1.795 [95%CI 1.065-3.026], P = 0.028). In Kaplan-Meier curve, patients with impaired PEDSR are more likely to experience MACEs (P < 0.001). When subdivided by LVEF, PEDSR still makes a significant difference to MACEs in patients with LVEF > 50.28% (P = 0.003) but not in reduced LVEF patients (P = 0.204). PEDSR is also incremental to LVEF (Continuous NRI 0.515 [95%CI 0.268-0.763], P < 0.001), LVIS (Continuous NRI 0.576 [95%CI 0.330-0.822], P < 0.001), and LVMVO (Continuous NRI 0.576 [95%CI 0.330-0.822], P < 0.001). Finally, worse TIMI flow post-PCI (HR 3.353 [95%CI 1.603-7.016], P = 0.001) and LVEF (HR 0.920 [95%CI 0.900, 0.940], P < 0.001) are the risk factors for PEDSR impairment. Conclusions：CMR-derived PEDSR can significantly predict MACEs with the discriminative power not inferior to LVEF, LVIS and LVMVO. Circumf. PEDSR ≤ 0.665%/s is an independent predictive factor of MACEs and is incremental in the prognostic risk stratification of STEMI.

Myocardial strain overrules left ventricular ejection fraction and late gadolinium enhancement extent in predicting MACE in CMR-proven acute myocarditis

Abstract Funding Acknowledgements Type of funding sources: None. Background Cardiac magnetic resonance (CMR) plays a major role in both the diagnostic process and prognostic stratification in acute myocarditis. Presence of late gadolinium enhancement (LGE) and left ventricular (LV) ejection fraction (EF) are known predictors of major adverse cardiovascular events (MACE). However, in daily clinical practice it remains challenging to distinguish ‘the good from the bad’. The prognostic value of CMR feature tracking (FT) derived strain, with respect to LGE and LVEF, remains unclear. Purpose To evaluate the incremental prognostic value of left atrial (LA) phasic function, LV and right ventricular (RV) strain using CMR-FT in patients with CMR-proven acute myocarditis. Methods In this multicenter observational study, patients with CMR-proven acute myocarditis were included and followed with regard to MACE including all-cause mortality (ACM), heart-failure hospitalizations (HFH), and life-threatening arrhythmias (LTA). Using FT-derived strain, LV global longitudinal strain (GLS), circumferential strain (GCS), and radial strain (GRS), RV GLS and LA phasic function were measured. Uni- and multivariable analysis including clinical and CMR parameters were performed to assess the association with MACE. Results A total of 162 patients were included (75% male, 41 ±17 years). MACE occurred in 29 patients (18%, ACM n = 18, HFH n = 7, LTA n = 11) during a median follow-up of 5.5 (2.2-8.3) years. Forty-six percent had a STEMI-like presentation (combination of chest pain, elevated troponin, and ST-elevation, n = 74). LGE was present in 90% of patients and mean LVEF was 51 ± 12%. Patients with LVEF <50% had a significantly worse prognosis compared to patients with LVEF ≥50% (p < 0.0001, Figure A). When we categorized the study population into subgroups of quartile values of LV GLS, patients with LV GLS worse than 18% had a significant worse outcome compared to the other subgroups (p < 0.05, Figure B). Subgroups of LGE extent did not show significantly different associations with outcome (p = 0.458, Figure C). Cox regression analysis showed that LV strain and LA phasic function were univariably associated with MACE, whereas RV GLS and LGE extent were not. All univariable associated strain parameters were separately included in a multivariable model, including age, sex, STEMI-like presentation, and LVEF. LV GLS (HR 1.08, p = 0.01), LV GCS (HR 1.15, p = 0.02), and LV GRS (HR 0.98, p = 0.02) were independent predictors of MACE. Conclusions LV strain parameters are independent and incremental predictors of prognosis in patients with acute myocarditis, while RV strain and LA phasic function are not. Therefore, LV strain is a promising novel parameter for risk stratification in acute myocarditis.

Additional diagnostic value of cardiac magnetic resonance feature tracking in patients with biopsy-proven arrhythmogenic cardiomyopathy

BackgroundWe aim to evaluate the value of Cardiac magnetic resonance (CMR) feature tracking (CMR-FT) in addition to Task Force Criteria(TFC) in patients with (arrhythmogenic cardiomyopathy) AC biopsy-proved. MethodsThirty-five patients with AC histologically proven who performed CMR with late gadolinium enhancement (LGE) acquisition were enrolled. The study population was divided in Group1 (negative CMR TFC and LV ejection fraction≥55%) and Group2 (positive CMR TFC and/or LVEF<55%) and compared to an age and gender-matched control group. CMR datasets of all patients were analyzed to calculate LV indexed end-diastolic (LVEDi) and end-systolic (LVESi) volumes and RV indexed end-diastolic (RVEDi) and end-systolic (RVESi) volumes, both LV ejection fraction (LVEF) and RV ejection fraction (RVEF). Moreover, LV and RV global longitudinal (GLS), circumferential (GCS) and radial (GRS) strain were measured. ResultsThe AC patients showed both higher LVEDi (p:0.002) and RVEDi (p:0.017) and lower LVEF (p: 0.016) as compared to control patients. Moreover, AC patients showed impaired LV-GLS (p < 0.001), LV-GRS (p < 0.001), LV-GCS (p < 0.001) and RV-GRS (p:0.026) as compared to control subjects. Group1 patients showed a significant reduction of LV-GRS (p < 0.05) and LV-GCS p < 0.01) as compared to control subjects. At univariate analysis LV-GCS was the most discriminatory parameter between Group1 vs heathy subjects with an optimal cut-off of −15.8 (Sensitivity: 74%; Specificity: 10%). ConclusionsIn patients with AC biopsy-proven, CMR-FT could improve the diagnostic yield in the subset of patients who results negative for imaging TFC criteria resulting as useful gatekeeper for indication of myocardial biopsy in case of equivocal clinical and imaging presentation.

Right Ventricular Contraction Patterns in Patients Undergoing Transcatheter Tricuspid Valve Repair for Severe Tricuspid Regurgitation.

This study investigated patterns of right ventricular (RV) contraction by using cardiac magnetic resonance (CMR) imaging in patients undergoing transcatheter tricuspid valve repair (TTVR). The role of RV function in patients with severe tricuspid regurgitation undergoing TTVR is poorly understood. Global RV dysfunction was defined as CMR-derived RV ejection fraction (RVEF)≤45% and longitudinal RV dysfunction was defined as tricuspid annular plane systolic excursion (TAPSE)<17mm on echocardiography. Patients were stratified into 3 types of RV contraction: type I, TAPSE≥17 and RVEF >45%; type II, TAPSE<17 and RVEF >45%; and type III, TAPSE<17 and RVEF≤45%. CMR feature tracking was performed to assess longitudinal and circumferential RV strain. The primary outcome was a composite of all-cause mortality or first heart failure hospitalization. Of 79 patients (median age 79 years, 51% female), 18 (23%) presented with global and 40 (51%) presented with longitudinal RV dysfunction. The composite outcome occurred in 22 patients (median follow-up 362days). Global RV dysfunction but not longitudinal RV dysfunction (hazard ratio: 6.62; 95% confidence interval: 2.77-15.77; and hazard ratio: 1.30; 95% confidence interval: 0.55-3.08, respectively) was associated with the composite outcome. Compared with type I RV contraction, patients with type II RV contraction exhibited increased circumferential strain, with a preservation of RVEF despite diminished longitudinal strain. Patients with type III RV contraction exhibited both diminished longitudinal and circumferential strain, resulting in an impaired RVEF. Patients with type III RV contraction showed the worst survival (P< 0.001). Global RV dysfunction is a predictor of outcomes among TTVR patients. Tricuspid regurgitation patientscan be stratified into 3 types of RV contraction, in which a loss of longitudinal function can be compensated by increasing circumferential function, preserving RVEF and favorable outcomes.

Clinical value of left ventricular strain analysis by cardiovascular magnetic resonance in patients with coronary chronic total occlusion

Objective: To explore the clinical value of quantitatively assessment of left ventricular strain in patients with coronary chronic total occlusion (CTO) by cardiac magnetic resonance imaging (CMR)-feature tracking (CMR-FT) technique. Methods: In this retrospective and observation study, patients with single CTO, who underwent CMR examination in Beijing Anzhen Hospital from November 2014 to January 2019, were selected as case group (CTO group), and those without cardiovascular diseases defined by echocardiography, electrocardiogram (ECG) and clinical history and with normal CMR results were selected as healthy control group (control group). General clinical data including age, gender, discharge diagnosis, and the examination results of echocardiography and ECG were obtained from the electronic medical record system. Two-dimensional CMR-FT was applied to measure left ventricle (LV) global peak radial, circumferential, and longitudinal strains (GPRS, GPCS and GPLS, respectively), and the regional myocardial strain in the target vessel area of CTO was analyzed. Grayscale thresholds of 5 standard deviations (SDs) were used to quantify late gadolinium enhancement (LGE). Patients with CTOs were divided into infract size>10% group and infarct size≤10% group, and left ventricular ejection fraction (LVEF)≥50% group and LVEF<50% group, respectively. The differences between various groups were compared. Results: There were 52 patients in CTO group (34 males, age (54.1±11.7) years, body mass index (BMI) (26.2±2.5)kg/m2) and 30 patients in control group (14 males, age(51.6±12.3)years, BMI (25.6±3.3)kg/m2). There was no significant difference in age, gender, and BMI between the two groups (all P>0.05). LVEF, GPRS, GPCS and GPLS were significantly lower in CTO group than in control group (all P<0.05), left ventricular volume (LVEDV) was similar between the two groups (P>0.05). Among the patients with CTO, there were 26 patients with infarct size>10% and 26 patients with infarct size≤10%. GPRS, GPCS and GPLS were significantly lower (all P<0.05), while LVEF and LVEDV were similar in CTO patients with infarct size≤10% as compared to control group (both P>0.05). LVEF, GPRS, GPCS and GPLS were significantly lower (all P<0.05), while LVEDV was similar in CTO patients with infarct size>10% (P>0.05) as compared to control group. GPRS and GPCS were significantly lower (both P<0.05), while LVEF, LVEDV and GPLS were similar in CTO patients with infarct size>10% as compared to infarct size≤10% group. There were 40 subjects in LVEF≥50% group and 12 subjects in LVEF<50% group. Compared with the control group, GPCS and GPLS of CTO patients were significantly lower in LVEF≥50% group and LVEF<50% group (all P<0.01), LVEF and LVEDV was similar in CTO patients with LVEF≥50% (both P>0.05), but LVEF was lower and LVEDV was larger in LVEF<50% group (both P<0.05). The GPRS, GPCS, GPLS and LVEF of CTO patients in LVEF ≥ 50% group were higher than those in LVEF<50% group (all P<0.0l), and the myocardial infarction size was smaller than that in LVEF reduced group (P<0.0l), but there was no significant difference in LVEDV between the two groups (P=0.07). In the CTO group, there were 21 patients with left anterior descending artery (LAD) occlusion and 126 segments supplied by the target vessels. The peak radial strain (PRS), circumferential strain (PCS) and longitudinal strain (PLS) in the blood supply area were lower than those in the control group (all P<0 01). In 7 patients with left circumflex artery (LCX) occlusion, the number of myocardial segments supplied by the target vessels was 35, and the PRS, PCS and PLS in the target vessel supply area were lower than those in the control group (all P<0 05). In 24 patients with right coronary artery (RCA) occlusion, the number of myocardial segments supplied by the target vessels was 120, and the PRS, PCS and PLS in the target vessel supply area were lower than those in the control group (all P<0.01). Among the 126 segments in 21 patients with LAD CTO, 91 (72.2%) segments had infarct size≤25%, 17 (13.5%) segments had infarct size between 26%-50%, 11 segments (8.7%) had infarct size between 51%-75%, and 7 (5.6%) segments had infarct size between 76%-100%. Among the 35 segments in 7 patients with LCX CTO, 31 (88.6%) segments had infarct size≤25%, and 4 (11.4%) segments had infarct size between 26%-75%. Among the 120 segments in 24 patients with RCA CTO, 96 (80.0%) segments had infarct size≤25%, 11 (9.2%) segments had infarct size between 26%-50%, 8 (6.7%) segments had infarct size between 51%-75%, and 5 segments (4.2%) had infarct size between 76%-100%. Conclusions: In this study with single CTO, although the LVEF is preserved in the majority of the patients, the left ventricular global and regional strain values are significantly decreased. The larger the infarct size, the greater the impact on radial and circumferential motion, reflecting the early impairment of left ventricular function in these patients.

How does iron deposition modify the myocardium? A feature-tracking cardiac magnetic resonance study.

Iron-overload cardiomyopathy is the principal cause of mortality in thalassemia. Via feature-tracking cardiac magnetic resonance (FT-CMR), we investigated alterations in cardiac deformation with the progression in myocardial iron overload (MIO). We enrolled 154 patients with thalassemia (50.64% male, mean age = 32.19 ± 9.79 years) referred for MIO assessment and 28 controls (50% male, mean age = 31.07 ± 4.35 years). Functional, strain, and T2* values were assessed in 4 study groups: no MIO (T2* > 20), mild-to-moderate MIO (T2* = 10-20), severe MIO (T2* < 10), and healthy controls. The recorded strain values were compared between the groups. The study groups were statistically significantly different vis-à-vis left ventricular (LV) global longitudinal strain (GLS) (F [3, 178] = 20.30), LV global radial strain (GRS) (F [3, 178] = 11.61), right ventricular (RV) GLS (F [3, 178]) = 5.32), RV global circumferential strain (GCS) (F [3, 178] = 26.02), and RVGRS (F [3, 178] = 16.86) (Ps < 0.005). The post hoc test revealed that LVGLS, RVGCS, and RVGRS were different between patients with thalassemia but without MIO and the control group (Ps < 0.001). A significant difference in LVGLS and LVGRS was detected between the T2* > 20 and 10 ≤ T2* ≤ 20 groups (Ps < 0.05). The multivariate logistic regression analysis depicted LVGRS as the most robust predictor of MIO (T2* ≤ 20) (odds ratio = 0.920, 95% CI 0.886 to 0.955), which predicted MIO with a cutoff point of 31.16% or less (sensitivity = 62% and specificity = 80.77%). Biventricular FT-CMR values are impaired in patients with thalassemia even without MIO. With MIO progression, LV strain values are the first ones to be undermined. Notably, functional CMR indices are jeopardized late, only after severe iron deposition.

Impairment of left atrial function in pediatric patients with repaired tetralogy of Fallot: a cardiovascular magnetic resonance imaging study.

We aimed to assess left atrial (LA) strain before LA dilatation in patients with repaired tetralogy of Fallot (rTOF) compared with healthy controls. We also determined the effects of right atrial (RA) dilatation on LA performance using cardiovascular magnetic resonance-feature tracking (CMR-FT). Forty-nine pediatric patients with rTOF and 36 age- and sex-matched healthy controls were prospectively recruited between June 2017 and August 2019. Balanced steady-state free precession (2D b-SSFP) cine, 2D late gadolinium enhancement (LGE) and phase-contrast (PC) sequences were acquired on 1.5 and 3.0 Tesla scanners. Both ventricular and atrial volumes and ejection fraction were measured. Left ventricular (LV) strain and diastolic strain rates were evaluated between the rTOF patient and control groups. LA reservoir (Ɛs), conduit (Ɛe), and booster strain (Ɛa) were determined at LV end-systole, LV diastasis, and pre-LA systole, respectively. The first derivatives of the respective strains yielded corresponding peak strain rates. Statistical analysis was performed using the t-test and Mann-Whitney test for parametric and non-parametric variables, respectively. Correlations were assessed using Pearson's correlation coefficient for normally distributed variables and Spearman's correlation coefficient for non-parametric data. Intra-observer and inter-observer variabilities of LA strain and strain rate measurements were determined from ten randomly selected rTOF patients and ten control subjects. LA strain was significantly lower in patients with rTOF compared with controls (Ɛs, P < 0.001; Ɛe, P = 0.002; Ɛa, P < 0.001). The correlations between LA strain and RA stroke volume indices (SVi) and RA ejection fraction (EF) were moderate (Ɛs and SVi, r = 0.538, P < 0.001; Ɛs and RA EF, r = 0.493, P < 0.001; Ɛe and SVi, r = 0.532, P < 0.001; Ɛe and RA EF, r = 0.466, P < 0.001). LA strain and strain rates had good reproducibility in intra-observer and inter-observer analyses. LA strain and strain rates decreased in pediatric patients with rTOF compared with controls before LA enlargement. A dysfunction in LA performance might precede LV dysfunction in patients with rTOF, even in the early stages after repair.

Age- and Sex-Specific Changes in CMR Feature Tracking-Based Right Atrial and Ventricular Functional Parameters in Healthy Asians.

Cardiovascular magnetic resonance (CMR) is the reference standard for non-invasive assessment of right-sided heart function. Recent advances in CMR post-processing facilitate quantification of tricuspid annular (TA) dynamics and longitudinal strains of the right ventricle (RV) and right atrium (RA). We aimed to determine age- and sex-specific changes in CMR-derived TA dynamics, and RV and RA functional parameters in healthy Asian adults. We studied 360 healthy subjects aged 21–79 years, with 30 men and 30 women in each of the six age groups. Functional parameters of RV and RA were measured on standard four-chamber cine CMR using fast feature tracking: (1) TA peak velocities (systolic velocity S′, early diastolic velocity E′, late diastolic velocity A′) and TA plane systolic excursion (TAPSE); (2) RV global longitudinal strain (GLS) and strain rates; and (3) RA phasic longitudinal strains and strain rates. S′ and TAPSE exhibited negative correlations with age. RV GLS was significantly higher in females than in males but not associated with age in both sexes. Females had similar E′, lower A′, and higher E′/A′ ratios compared to males. Positive associations of E′ and E′/A′, and negative association of A′ with age were observed in both sexes. Females had higher RA reservoir and conduit strains compared to males. There were significantly negative and positive associations between RA conduit and booster strains, respectively, with age. Age- and sex-specific reference ranges were established, and associations revealed, for fast CMR feature tracking parameters of right heart function in a large normal Asian population.

Risk stratification of patients with Brugada syndrome: the impact of myocardial strain analysis using cardiac magnetic resonance feature tracking

ObjectiveThis study evaluated the prognostic significance of cardiac magnetic resonance myocardial feature tracking (CMR-FT) in patients with Brugada syndrome (BrS) to detect subclinical alterations and predict major adverse events (MAE). MethodsCMR was performed in 106 patients with BrS and 25 healthy controls. Biventricular global strain analysis was assessed using CMR-FT. Patients were followed over a median of 11.6 [8.8 ± 13.8] years. ResultsThe study cohort was subdivided according to the presence of a spontaneous type 1 ECG (sECG) into sBrS (BrS with sECG, n = 34 (32.1%)) and diBrS (BrS with drug-induced type 1 ECG, n = 72 (67.9%)). CMR-FT revealed morphological differences between sBrS and diBrS patients with regard to right ventricular (RV) strain (circumferential (%) (sBrS −7.9 ± 2.9 vs diBrS - 9.5 ± 3.1, p = 0.02) and radial (%) (sBrS 12.0 ± 4.3 vs diBrS 15.4 ± 5.4, p = 0.004)). During follow-up, MAE occurred in 11 patients (10.4%). Multivariable analysis was performed to identify independent predictors for the occurrence of events during follow-up. The strongest predictive value was found for RV circumferential strain (OR 3.2 (95% CI 1.4 - 6.9), p = 0.02) and RVOT/BSA (OR 3.1 (95% CI 1.0 - 7.0), p = 0.03). ConclusionsMyocardial strain analysis detected early subclinical alterations, prior to apparent changes in myocardial function, in patients with BrS. While usual functional parameters were within the normal range, CMR-FT revealed pathological results in patients with an sECG.Moreover, RV circumferential strain and RVOT size provided additional prognostic information on the occurrence of MAE during follow-up, which reflects electrical vulnerability.

Comprehensive assessment of left atrial and ventricular remodeling in paroxysmal atrial fibrillation by the cardiovascular magnetic resonance myocardial extracellular volume fraction and feature tracking strain

Atrial fibrillation (AF) is a progressive disease that starts with structural or functional changes in the left atrium and left ventricle, and evolves from paroxysmal toward sustained forms. Early detection of structural or functional changes in the left atrium and left ventricle in the paroxysmal stage could be useful for identifying a higher risk of progression to persistent AF and future cardio-cerebrovascular events. The aim of this study was to test the hypothesis that the feature tracking (FT) left atrial (LA) strain and left ventricular (LV) extracellular volume fraction (ECV) derived from cardiovascular magnetic resonance (CMR) could detect early changes in remodeling of the left atrium and ventricle in the paroxysmal AF (PAF) stage. The participants were comprised of 106 PAF patients (age, 66.1 ± 10.7 years; 66% male) who underwent clinical CMR before pulmonary vein isolation and 20 control subjects (age, 68.3 ± 8.6 years; 55% male). The CMR-FT LA strain/phasic function and LV-ECV were compared between the PAF and control groups. The total and passive LA empty fraction (LAEF) and LA strain (corresponding to LA reservoir and conduit function) were decreased in the PAF group as compared to the control group. However, active LAEF (corresponding to the LA booster pump function) did not differ significantly between the PAF group (33.9 ± 10.9%) and control group (37.9 ± 13.3%, p = 0.15), while the active LA strain (corresponding to the LA booster pump function) was significantly decreased in the PAF group (11.4 ± 4.3 vs. 15.2 ± 5.6%, p = 0.002). The LV-ECV was significantly greater in the PAF group (28.7 ± 2.8%) than control group (26.6 ± 2.0%, p = 0.002). In the PAF group, the LV-ECV correlated significantly with the E/e′ and LA volume index. Regarding the LA strain, correlations were seen between the LV-ECV and both the reservoir function and conduit function. CMR-FT LA strain in combination with the LV-ECV in a single clinical study offers a potential imaging marker that identifies LA/LV remodeling including subtle LA booster pump dysfunction undetectable by the conventional booster pump LAEF in the PAF stage.

Efficacy of Novel Noncontrast Cardiac Magnetic Resonance Methods in Indicating Fibrosis in Hypertrophic Cardiomyopathy.

Objective In hypertrophic cardiomyopathy (HCM), myocardial fibrosis is routinely shown by late gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR) imaging. We evaluated the efficacy of 2 novel contrast-free CMR methods, namely, diffusion-weighted imaging (DWI) and feature-tracking (FT) method, in detecting myocardial fibrosis. Methods This cross-sectional study was conducted on 26 patients with HCM. Visual and quantitative comparisons were made between DWI and LGE images. Regional longitudinal, circumferential, and radial strains were compared between LGE-positive and LGE-negative segments. Moreover, global strains were compared between LGE-positive and LGE-negative patients as well as between patients with mild and marked LGE. Results All 3 strains showed significant differences between LGE-positive and LGE-negative segments (P < 0.001). The regional longitudinal and circumferential strain parameters showed significant associations with LGE (P < 0.001), while regional circumferential strain was the only independent predictor of LGE in logistic regression models (OR: 1.140, 95% CI: 1.073 to 1.207, P < 0.001). A comparison of global strains between patients with LGE percentages of below 15% and above 15% demonstrated that global circumferential strain was the only parameter to show impairment in the group with marked myocardial fibrosis, with borderline significance (P=0.09). A review of 212 segments demonstrated a qualitative visual agreement between DWI and LGE in 193 segments (91%). The mean apparent diffusion coefficient was comparable between LGE-positive and LGE-negative segments (P=0.51). Conclusions FT-CMR, especially regional circumferential strain, can reliably show fibrosis-containing segments in HCM. Further, DWI can function as an efficient qualitative method for the estimation of the fibrosis extent in HCM.

Feature-tracking cardiac magnetic resonance left ventricular global longitudinal strain improves 6\xa0months after kidney transplantation associated with reverse remodeling, not myocardial tissue characteristics

To determine whether left ventricular (LV) global longitudinal strain (GLS) measured by feature-tracking (FT) cardiac magnetic resonance (CMR) improves after kidney transplantation (KT) and to analyze associations between LV GLS, reverse remodeling and myocardial tissue characteristics. This is a prospective single-center cohort study of kidney transplant recipients who underwent two CMR examinations in a 3T scanner, including cines, tagging, T1 and T2 mapping. The baseline exam was done up to 10 days after transplantation and the follow-up after 6 months. Age and sex-matched healthy controls were also studied for comparison. A total of 44 patients [mean age 50 ± 11 years-old, 27 (61.4%) male] completed the two CMR exams. LV GLS improved from − 13.4% ± 3.0 at baseline to − 15.2% ± 2.7 at follow-up (p < 0.001), but remained impaired when compared with controls (− 17.7% ± 1.5, p = 0.007). We observed significant correlation between improvement in LV GLS with reductions of left ventricular mass index (r = 0.356, p = 0.018). Improvement in LV GLS paralleled improvements in LV stroke volume index (r = − 0.429, p = 0.004), ejection fraction (r = − 0.408, p = 0.006), global circumferential strain (r = 0.420, p = 0.004) and global radial strain (r = − 0.530, p = 0.002). There were no significant correlations between LV GLS, native T1 or T2 measurements (p > 0.05). In this study, we demonstrated that LV GLS measured by FT-CMR improves 6 months after KT in association with reverse remodeling, but not native T1 or T2 measurements.

Prognostic Value of Feature-Tracking Right Ventricular Longitudinal Strain in Severe Functional Tricuspid Regurgitation: A Multicenter Study

ObjectivesThis study sought to evaluate the prognostic value of cardiac magnetic resonance (CMR) feature-tracking–derived right ventricular (RV) free wall longitudinal strain (RVFWLS) in a large multicenter population of patients with severe functional tricuspid regurgitation. BackgroundTricuspid regurgitation imposes a volume overload on the RV that can lead to progressive RV dilation and dysfunction. Overt RV dysfunction is associated with poor prognosis and increased operative risk. Abnormalities of myocardial strain may provide the earliest evidence of ventricular dysfunction. CMR feature-tracking techniques now allow assessment of strain from routine cine images, without specialized pulse sequences. Whether abnormalities of RV strain measured using CMR feature tracking have prognostic value in patients with tricuspid regurgitation is unknown. MethodsConsecutive patients with severe functional tricuspid regurgitation undergoing CMR at 4 U.S. medical centers were included in this study. Feature-tracking RVFWLS was calculated from 4-chamber cine views. The primary endpoint was all-cause death. Cox proportional hazards regression modeling was used to examine the independent association between RVFWLS and death. The incremental prognostic value of RVFWLS was assessed in nested models. ResultsOf the 544 patients in this study, 128 died during a median follow-up of 6 years. By Kaplan-Meier analysis, patients with RVFWLS ≥median (−16%) had significantly reduced event-free survival compared with those with RVFWLS <median (log-rank p < 0.001). By Cox multivariable regression modeling, RVFWLS was associated with increased risk-of-death after adjustment for clinical and imaging risk factors, including RV size and ejection fraction (hazard ratio: 1.14 per %; p < 0.001). Addition of RVFWLS in this model resulted in significant improvement in the global chi-square (31 to 78; p < 0.001). ConclusionsCMR feature-tracking–derived RVFWLS is an independent predictor of mortality in patients with severe functional tricuspid regurgitation, incremental to common clinical and imaging risk factors.

Characterization of subclinical diastolic dysfunction by cardiac magnetic resonance feature-tracking in adult survivors of non-Hodgkin lymphoma treated with anthracyclines

BackgroundThe use of anthracycline-based chemotherapy is associated with the development of heart failure, even years after the end of treatment. Early detection of cardiac dysfunction could identify a high-risk subset of survivors who would eventually benefit from early intervention. Cardiac magnetic resonance feature-tracking (CMR-FT) analysis offers a practical and rapid method to calculate systolic and diastolic strains from routinely acquired cine images. While early changes in systolic function have been described, less data are available about late effects of chemotherapy in diastolic parameters by CMR-FT. The main goal of this study was to determine whether left ventricular (LV) early diastolic strain rates (GDSR-E) by CMR-FT are impaired in long-term adult survivors of non-Hodgkin lymphoma (NHL). Our secondary objective was to analyze associations between GDSR-E with cumulative anthracycline dose, systolic function parameters and myocardial tissue characteristics.MethodsThis is a single center cross-sectional observational study of asymptomatic patients in remission of NHL who previously received anthracycline therapy. All participants underwent their CMR examination on a 3.0-T scanner, including cines, T2 mapping, T1 mapping and late gadolinium enhancement imaging. Derived myocardial extracellular volume fraction was obtained from pre- and post-contrast T1 maps. CMR-FT analysis was performed using Trufi Strain software. The data obtained were compared between anthracycline group and volunteers without cardiovascular disease or neoplasia.ResultsA total of 18 adult survivors of NHL, 14 (77.8%) males, at mean age of 57.6 (± 14.7) years-old, were studied 88.2 (± 52.1) months after exposure to anthracycline therapy (median 400 mg/m2). Compared with controls, anthracycline group showed impaired LV global early diastolic circumferential strain rate (GCSR-E) [53.5%/s ± 19.3 vs 72.2%/s ± 26.7, p = 0.022], early diastolic longitudinal strain rate (GLSR-E) [40.4%/s ± 13.0 vs 55.9%/s ± 17.8, p = 0.006] and early diastolic radial strain rate (GRSR-E) [− 114.4%/s ± 37.1 vs − 170.5%/s ± 48.0, p < 0.001]. Impaired LV GCSR-E, GLSR-E and GRSR-E correlated with increased anthracycline dose and decreased systolic function. There were no correlations between GDSR-E and myocardial tissue characteristics.ConclusionsLeft ventricular early diastolic strain rates by CMR-FT are impaired late after anthracycline chemotherapy in adult survivors of non-Hodgkin lymphoma.

Comparison between cardiac magnetic resonance and speckle-tracking echocardiography in prediction of cardiac resynchronization therapy outcomes

Background Cardiac resynchronization therapy (CRT) improves quality of life, exercise tolerance, and myocardial function in a considerable number of patients with heart failure (HF) and left bundle branch block. In addition, CRT decreases HF hospitalizations and overall mortality. However, structural, morbidity, and mortality improvements after CRT rate between 40 and 60%. Objective To compare the role of the cardiac magnetic resonance (CMR) and speckle-tracking echocardiography (STE) in expectation of response to CRT. Patients and methods We investigated the predictors of CRT response using CMR measurement of left ventricular (LV) volumes and function, CMR-derived mechanical dyssynchrony, scar percentage, and its relation to the site of LV lead implantation, in comparison with STE in prediction of CRT outcomes. Results A total of 35 patients with HF planned for CRT were included. Echocardiography was used to define the response to CRT (15% reduction in LV end-systolic volume 6 months after implantation). At follow-up, 18 (51.43%) patients were categorized as responders. Echocardiographic speckle-tracking radial strain analysis showed a significant LV dyssynchrony in responders versus nonresponders (radial mid-anteroseptal and posterior wall delays were 245.1 ms and 80.7 ms, respectively) (P&lt;0.0001). LV radial dyssynchrony, as measured by CMR-feature tracking, was significantly higher in responders versus nonresponders (mean of SDt-16 of radial strain were 232.7 ms vs. 180.4 ms, P&lt;0.0001), and median of radial mid-anteroseptal-to-inferolateral wall delay was 375 vs. 125.4 ms, P&lt;0.0001). Late contrast-enhanced CMR was performed for scar assessment. It was noticed that scar percentage of LV mass was much higher in nonresponders (median 6.2 vs. 0%) (P=0.005). Conclusion CMR imaging offers the unique opportunity to predict the CRT outcomes by measurement of LV volumes, LV mechanical dyssynchrony (that well correlated with that of STE), and the total scar percentage and distribution in a single examination.