Absence Of Late Gadolinium Enhancement Research Articles

The emerging role of cardiovascular magnetic resonance in the evaluation of cardiac involvement in systemic sclerosis

Abstract Systemic sclerosis (SSc) is an autoimmune rheumatic disease, characterized by vascular, inflammatory and fibrotic alterations. Cardiac involvement is the « fatal tip of the iceberg» in SSc, as it leads to high morbidity/mortality. Cardiovascular imaging modalities play an important role in the early diagnosis and treatment assessment of cardiac involvement. Echocardiography is the corner stone for evaluation of cardiac involvement, providing information about function, wall motion, pulmonary pressure, pericardium and valvular disease. It is a low-cost modality, widely available, without radiation and with great experience among cardiologists. However, it is a window and operator dependent modality and cannot provide tissue characterization information, absolutely necessary for diagnosis and treatment of cardiac involvement in SSc. Cardiovascular magnetic resonance (CMR) can perform myocardial function and tissue characterization in the same examination without radiation, has excellent reproducibility and is window and operator independent. The great advantage of CMR is the capability to assess peri- myo-vascular inflammation, myocardial ischemia and presence of replacement and diffuse myocardial fibrosis in parallel with ventricular function assessment. The modified Lake Louise criteria including T2, native T1 mapping and extracellular volume fraction (ECV) has been recently used to diagnose inflammatory cardiomyopathy. According to expert recommendations, myocardial inflammation should be considered if at least 2 indices, one T2 and one T1 parameter are positive, whereas native T1 mapping and ECV assess diffuse fibrosis or oedema, even in the absence of late gadolinium enhancement (LGE). Moreover, transmural/subendocardial LGE following the distribution of coronary arteries and diffuse subendocardial fibrosis not related with epicardial coronary arteries are indicative of epicardial and micro-vascular coronary artery disease, respectively. To conclude, CMR can overcome the limitations of echocardiography by identifying acute/active or chronic myocardial inflammation/fibrosis, ischemia and myocardial infarction using classic and parametric indices in parallel with biventricular function assessment

Absence of late gadolinium enhancement and outcomes of cardiac resynchronization therapy in non-ischemic dilated cardiomyopathy

Abstract Background Among patients with non-ischemic dilated cardiomyopathy (DCM) with indication for cardiac resynchronization therapy (CRT), there are no clear recommendations about who should receive a CRT-defibrillator (CRT-D) and who should have CRT-pacemaker (CRT-P). Absence of late gadolinium enhancement (LGE) at cardiac magnetic resonance (CMR) has a high negative predictive value for ventricular arrhythmias (VA) and sudden death (SD) in DCM and is a predictor of reverse remodelling in several scenarios. Purpose To evaluate the association between absence of LGE and VA/SD or echocardiographic response to CRT in DCM patients treated with CRT. Methods Multicenter retrospective observational cohort study including consecutive DCM patients with de-novo CRT implant and with available CMR. The primary endpoints were: 1) a combined arrhythmic endpoint including appropriate defibrillator therapies, sustained VA and sudden death. 2) echocardiographic response to CRT, intended as an increase ≥10% in left ventricular ejection fraction (LVEF). Results We included 167 patients, 55% males, with median QRS duration of 160ms and median LVEF of 25%. LGE was present in 46% of cases (LGE+). A CRT-D was implanted in 73% of patients. Median follow-up was 63 months. Of note, among patients without LGE (LGE-) we did not record any event of the combined arrhythmic endpoint. The cumulative incidence of the arrhythmic endpoint was significantly higher in LGE+ than in LGE- patients (25% vs 0%, p<0.001) and LGE was an independent predictor of this endpoint (adjusted HR 42, p<0.001). The proportion of responders to CRT was significantly higher in LGE- than in LGE+ cases (81% vs 53%, p<0.001); absence of LGE was the strongest predictor of echocardiographic response to CRT at multivariate analysis (adjusted OR 4.1, p=0.001). Super-responders (i.e. those with LVEF≥50% at follow-up) were also more frequent among LGE- than LGE+ patients (46% vs 21%, p=0.001) and absence of LGE was an independent predictor of LVEF normalization (HR 2.6, p=0.03). Conclusions Among DCM patients who receive CRT, those without LGE have an extremely low (or null in this case) arrhythmic risk and, at the same time, they have a high probability of echocardiographic response to CRT. Thus, LGE- patients could be ideal candidates for CRT-P instead of CRT-D.

Abnormal Global Longitudinal Strain Correlates with Amyloidogenic Light Chain-Induced Cardiac Dysfunction via Direct Myocardial Toxicity in Patients without Significant Amyloid Fibril Deposition

Introduction: Patients with advanced cardiac AL have high early mortality despite receiving effective plasma cell-directed therapies. Cardiac dysfunction is caused by direct myocardial toxicity from amyloidogenic light chains (LCs) and architectural distortion from amyloid fibril deposition. Diagnosis before significant fibril-induced cardiac dysfunction is critical for improving outcomes. While measuring cardiac biomarkers is standard for risk stratification of patients with newly diagnosed AL, serum concentrations can be impacted by fluid shifts and renal impairment, suggesting a need for complementary biomarkers. Our transcriptomic analysis highlighted dysregulation of myocardial contractility in cardiac cells exposed to amyloidogenic LCs, leading us to hypothesize that there could be clinically measurable differences in cardiac contractility (Ghosh et al., 2023). Global longitudinal strain (GLS) is a sensitive echocardiographic measure of myocardial contractility and may predict survival independent of serum cardiac biomarkers. Since LC-induced cardiac dysfunction via direct myocardial toxic effects is reversible with plasma cell-directed therapy and may represent an early cardiac insult in patients with cardiac AL, we identified and evaluated patients with LC-induced cardiac dysfunction and no clinical or echocardiographic evidence of significant cardiac amyloid fibril deposition to determine clinical features potentially associated with early cardiac AL. Methods: We analyzed the demographic, clinical, and echocardiographic features of patients with non-cardiac biopsy-proven AL amyloidosis and LC-induced cardiac dysfunction seen at the Boston University Amyloidosis Center between January 1, 2011 and March 31, 2023. Direct LC-induced cardiac dysfunction was defined as: (1) elevated cardiac biomarkers (BNP >176 pg/mL or NT-proBNP >899 pg/mL or troponin I >0.033 ng/mL, per institutional reference ranges); (2) normal echocardiographic interventricular septal thickness (<11 mm in males and <10 mm in females); (3) estimated glomerular filtration rate >60 mL/min/1.73m 2; (4) absence of late gadolinium enhancement on cardiac magnetic resonance imaging (if performed); and (5) negative endomyocardial biopsy (if performed). Echocardiographic variables, including left ventricular ejection fraction (LVEF) and GLS, were collected from the electronic health record or post-processed manually using TomTec 2D CPA. All statistical analyses were performed using GraphPad Prism version 8©. Overall survival (OS) was evaluated using the Kaplan-Meier estimator and log rank tests. Results: Twenty-nine patients met our criteria for direct LC-induced cardiac dysfunction. Median age at diagnosis was 65 years (range: 46-83), and 55% of patients (n=16) were male ( Table 1). LC isotype was lambda in 69% (n=20) and kappa in 31% (n=9) of patients. The difference in free light chains (dFLC) was >50 mg/L in 62% (n=18) of patients at diagnosis.Additionally, 76% (n=22) of patients met criteria for Boston University stage II cardiac disease with mildly elevated cardiac biomarkers (median BNP 237 pg/mL, median troponin I 0.053 ng/mL). Among 16 patients for whom a GLS measurement was available, 81% (13/16) had an abnormal GLS (normal < -18%). Median and mean GLS were -15.5% (-7 to -21.7) and -15.3% ± 4.5, respectively ( Figure 1). Median OS was 5.2 years for the entire cohort. Conclusion: We found that a subset of patients with AL amyloidosis demonstrate cardiac dysfunction without substantial clinical or echocardiographic evidence of amyloid deposition; this we postulate to be the result of direct myocardial toxic effects by amyloidogenic LCs. Early cardiac biomarker stage and abnormal GLS were commonly associated with LC-induced cardiac dysfunctionin these patients.

Abstract 17726: Nonischemic Cardiomyopathy in Patients With Coronary Artery Disease

Introduction: Randomized trials in obstructive coronary artery disease (CAD) have largely shown no prognostic benefit from revascularization. While there are several potential reasons for the lack of benefit from coronary revascularization, an underexplored possibility is the presence of coexisting nonischemic myocardial pathology. Aim: We aimed to investigate the prevalence and prognostic significance of nonischemic cardiomyopathy (NICM) in CAD. Methods: We studied a large cohort of consecutive patients with obstructive CAD on coronary angiography who had cardiovascular magnetic resonance imaging (CMR) from 2004 to 2020 for clinical indications. CMRs were analyzed for this study for the presence and type of cardiomyopathy. Patients with normal left ventricular ejection fraction and no late gadolinium enhancement (LGE) were classified as having no cardiomyopathy. Ischemic cardiomyopathy (ICM) was defined by ischemic LGE or extensive hibernating myocardium in the absence of LGE. NICM was defined by nonischemic LGE, absence of LGE without hibernating myocardium, or morphological abnormalities of NICM such as left ventricular hypertrophy. The study endpoint was a composite of all-cause death or hospitalization for heart failure. Results: Among 3,027 patients (mean age 65 years, 24% women), 18% had no cardiomyopathy, 65% had only ICM, and 17% had NICM. Of those with NICM, 38% also had ICM (dual cardiomyopathy). At a median follow-up of 4.7 years, 1,112 patients experienced the study endpoint. On Kaplan-Meier analysis, patients with NICM had a higher cumulative incidence of the study endpoint compared with no cardiomyopathy and ICM (log-rank P<0.001 for both comparisons). On multivariable regression analyses, NICM was associated with a greater risk for the study endpoint-hazard ratio (HR) 1.77; 95% confidence interval (CI) 1.43-2.19; P<0.001 compared with no cardiomyopathy and HR 1.27; 95% CI 1.09-1.47; P=0.003 compared with ICM, after adjustment for potential confounders. Conclusions: NICM was identified in 1 in 6 patients with CAD and was associated with worse long-term outcomes compared with no cardiomyopathy and ICM. In patients with obstructive CAD, coexisting NICM may contribute to the lack of prognostic benefit from revascularization.

Absence of visible infarction on cardiac magnetic resonance imaging despite the established diagnosis of myocardial infarction by 4th Universal Definition of Myocardial Infarction.

Myocardial scarring due to acute myocardial infarction (AMI) can be visualized by late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) imaging. However, a recent study revealed a group of Type 1 AMI patients with undetectable myocardial injury on LGE. This study aims to describe these cases in detail and explore possible explanations for this new phenomenon. A total of 137 patients diagnosed with either ST-elevation myocardial infarction (STEMI) or non-ST-elevation myocardial infarction (non-STEMI) diagnosed according to the 4th Universal Definition of Myocardial Infarction underwent LGE-CMR after invasive coronary angiography. Fourteen of them (10.2%) showed no LGE and were included in the final study population. Most patients presented with acute chest pain, 3 patients were diagnosed as STEMI, and 11 as non-STEMI. Peak high-sensitive cardiac troponin T ranged from 45 to 1173 ng/L. A culprit lesion was identified in 12 patients. Severe coronary stenoses were found in five patients, while seven patients had subtotal to total coronary artery occlusion. Percutaneous coronary intervention was performed in 10 patients, while 2 patients required coronary artery bypass grafting and no intervention was required in 2 patients. Cardiac magnetic resonance was performed 30 (4-140) days after the initial presentation. Most patients showed preserved left ventricular ejection fraction on CMR. No alternative reasons for the rise/fall of high-sensitive cardiac troponin T were found. The absence of LGE on CMR in patients with Type 1 AMI is a new finding. While insufficient spatial resolution of LGE imaging, delayed CMR performance, spontaneous reperfusion, and coronary collaterals may provide some explanations, further investigations are required to fully understand this phenomenon.

Myocardial microstructure assessed by T1 mapping after on-pump and off-pump coronary artery bypass grafting.

The correlation between the release of cardiac biomarkers after revascularization, in the absence of late gadolinium enhancement (LGE) or myocardial edema, and the development of myocardial tissue damage remains unclear. This study sought to identify whether the release of biomarkers is associated with cardiac damage by assessing myocardial microstructure on T1 mapping after on-pump (ONCAB) and off-pump coronary artery bypass grafting (OPCAB). Seventy-six patients with stable multivessel coronary artery disease (CAD) and preserved systolic ventricular function were included. T1 mapping, high-sensitive cardiac troponin I (cTnI), creatine kinase myocardial band (CK-MB) mass, and ventricular dimensions and function were measured before and after procedures. Of the 76 patients, 44 underwent OPCAB, and 32 ONCAB; 52 were men (68.4%), and the mean age was 63±8.5 years. In both OPCAB and ONCAB the native T1 values were similar before and after surgeries. An increase in extracellular volume (ECV) values after the procedures was observed, due to the decrease in hematocrit levels during the second cardiac resonance. However, the lambda partition coefficient showed no significant difference after the surgeries. The median peak release of cTnI and CK-MB were higher after ONCAB than after OPCAB [3.55 (2.12-4.9) vs. 2.19 (0.69-3.4) ng/mL, P=0.009 and 28.7 (18.2-55.4) vs. 14.3 (9.3-29.2) ng/mL, P=0.009, respectively]. Left ventricular ejection fraction (LVEF) was similar in both groups before and after surgery. In the absence of documented myocardial infarction, T1 mapping did not identify structural tissue damage after surgical revascularization with or without cardiopulmonary bypass (CPB), despite the excessive release of cardiac biomarkers.

Changes in CMR findings over time following acute Takotsubo cardiomyopathy

Takotsubo cardiomyopathy (TTS) is characterized by acute reversible left ventricular dysfunction showing typical left ventricular apical ballooning in the absence of obstructive coronary artery disease. Cardiac magnetic resonance (CMR) provides functional and inflammatory findings in contrast with the absence of late gadolinium enhancement (LGE). TTS generally heals within the first two weeks after the onset of symptoms, with the ECG and echocardiogram normalizing. However, data on CMR dynamics are scarce. In the present study, we aimed to describe how CMR findings change over time in acute TTS. Between December 2008 and May 2021, we retrospectively included all the patients hospitalized in the tertiary University Hospital of Angers, France who underwent CMR and received a diagnosis of acute TTS. Sixty-two patients fulfilled the diagnostic criteria from the 2018 ESC international expert consensus and underwent CMR. Patients were classified into three groups based on the delay between their first day of hospitalization and their assessment using CMR: less than five days (n = 31, 50%), between 5 and 15 days (n = 16, 25.8%), and more than 15 days [median 27 days (IQR: 20–36)] (n = 15, 24.2%). Compared to the 0–5 d group, the patients in the > 15 d group showed resolution of the LVEF alterations (55.9 ± 10.7 vs. 44.8 ± 13.3, P = 0.07), less apical akinesia (40% vs. 83%, P = 0.01) and normalized apical T2 values (44.5 ± 3.5 vs. 57 ± 2, P = 0.049). T1 and T2 quantitative measurements showed a base-to-apex gradient in 88.2% and 85.7% of patients, irrespective of the delay (P = 0.12 and P = 0.88). When CMR cannot be performed early after the onset of a suspected TTS, wall motion abnormalities disappear, and LVEF alteration resolve. However, a parametric assessment searching for a base-to-apex gradient in T1 and T2 values with higher apical values may be helpful to confirm the diagnosis. Main CMR findings at different time points (Fig. 1).

Use of Cardiac Magnetic Resonance Imaging to Distinguish Between Acute Myocarditis and Takotsubo Cardiomyopathy

Use of Cardiac Magnetic Resonance Imaging to Distinguish Between Acute Myocarditis and Takotsubo Cardiomyopathy

945 TRANSIENT LEFT VENTRICULAR THROMBOSIS TAKOTSUBO-RELATED

Abstract Background Takotsubo syndrome (TTS) is an increasingly widespread syndrome characterized by an acute and usually transient left ventricular (LV) dysfunction. Despite its transient nature, the acute phase can be characterized by serious complications such as LV thrombosis, as occurred in this case. Case description A 93-year-old woman was admitted to our emergency department due to a recent and self-limiting episode of acute chest pain. The ECG showed ST-elevation in leads V2, V3 and V4 (Fig.1), with cardiac biomarkers elevation. Transthoracic echocardiography (TTE) revealed apical akinesia and hypokinesia of the other LV segments with a severely reduced ejection fraction (EF 35%). Emergency coronary angiography showed normal epicardial coronary vessels. So, Takotsubo cardiomyopathy was hypothesized as diagnosis. A mass suspect for a thrombus was detected into the apex on day 3, despite a mild improvement of the other segments contraction (EF 40%), and clearly confirmed with the contrast echocardiography on day 5 (Fig.2). Unexpectedly, any LV thrombus was identified with cardiac MRI study performed on day 7 (Fig.3). Meanwhile, the patient never showed neurological disorders or other signs of thromboembolic complications. Echocardiography performed on day 11, before discharge, showed a great improvement of regional wall motion with residual LV apical hypokinesia (EF 55%) and no apical masses. Discussion This case emphasizes the need of frequent echocardiographic follow up in stress-induced cardiomyopathy, not only during the akinetic phase but also during the period of wall motion recovery, in order to diagnose and treat as soon as possible a LV apical thrombosis avoiding thromboembolic complications. We hypothesized that the early anticoagulation therapy combined with the initial improvement in LV wall motion facilitated the process of thrombosis resolution. Cardiac MRI played a relevant role in the comprehensive assessment of the functional and structural LV changes; the absence of late gadolinium enhancement (LGE) can be considered as a positive prognostic factor, indicating a complete resolution without residual fibrosis. Conclusion A multimodality imaging approach, based on a frequent echocardiographic follow up combined with cardiac MRI, is fundamental for an early diagnosis and a rapid treatment of LV thrombosis Takotsubo-related.

193 13 SECONDS OF ASYSTOLE IN YOUNG: IS A PACEMAKER NECESSARY?

Abstract Introduction Cardioinhibitory neurocardiogenic syncope (CNS) is caused by inappropriately trigger-activated cardiac reflex which finally precipitates asystole, sinus bradycardia, or atrioventricular block. In the absence of structural heart disease, the prognosis is excellent, but frequent syncopal episodes can have a significant impact on quality of life. No medical therapy has proved to be really effective and studies concerning pacemaker implantation are often controversial. However, in young individuals, especially those under 40 years of age, implanting a pacemaker may carry more risks than benefits. Thus, alternative techniques such as ablation of the cardiac atrial parasympathetic ganglia (GP) have emerged. Case report A 34-year-old man with frequent episodes of reflex syncope performed a tilt test in March 2022 that diagnosed cardio-inhibitory syncope with 13-second asystole interrupted with external cardiac massage and intravenous atropine. In May 2022 he had an MRI scan showing normal biventricular systolic function and absence of late-gadolinium enhancement and underwent loop recorder implantation. He came to our centre in June 2022 and underwent electrophysiological study and electroanatomical mapping of the right atrium (Carto 3) during general anaesthesia. The anatomical areas of the supero-posterior and infero-posterior GPs of the right atrium were identified by electroanatomical mapping of complex fractionated atrial electrograms (CFAE). Radiofrequency pulses (Thermocool 30 watts) were delivered at these points, resulting in the disappearance of the CFAEs and an increase in basal heart rate. The greatest number of ganglia are allocated on the posterior surface of the right atrium and in particular the supero-posterior GP is the nexus point for vagal input to the GPs before innervating the atria. Therefore, it was decided to localise and ablate exclusively the GPs of the right atrium. The procedure was completed without complications. The patient has not complained of any syncopal episodes since, and the loop has not recorded any significant pauses. Conclusions The anatomic ablation of GP only in the right atrium could represent a feasible method to reduce CNS, to increase the warning symptoms period, and to delay as much as possible pacemaker implant, especially in young patients who have experienced a related physical trauma. This approach significantly decreased the procedural time and risks.

Early detection of myocardial fibrosis in cardiomyopathy in the absence of late enhancement: role of T1 mapping and extracellular volume analysis.

To analyze myocardial fibrosis in dilated cardiomyopathy (DCM) patients with no late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) using T1 mapping and extracellular volume (ECV) and investigate the potential correlation with left ventricular (LV) dilation and dysfunction. The study included 41 DCM patients without LGE and 79 healthy controls. T1 and ECV were compared between the two groups using multivariable logistic regression analysis. The correlations between histological and functional parameters were evaluated using Pearson's correlation. Mean native myocardial T1 and ECV were significantly higher in the DCM group compared to controls (p ≤ 0.001, respectively). Multivariable logistic regression revealed that ECV (mean, minimum), LV ejection fraction (LVEF), and LV end-diastolic diameter (LVEDD) were independent discriminators for LGE-negative DCM; the area under the curve (AUC) of LVEF, LVEDD, ECV mean, and ECV minimum were 0.97, 0.96, 0.88, and 0.68, respectively. In the DCM group, LVEDD and LVEF were positively and negatively correlated with ECV, respectively. LVEDV index and LV end-systolic volume (LVESV) index were positively correlated with native-T1 and ECV, and the absolute value of LV global strain had a negative correlation with ECV. Early myocardial fibrosis in DCM could be detected by prolonged native T1 and elevated ECV despite the absence of LGE on CMR. Moreover, the change of histological characteristics of myocardium in DCM was correlated with LV dilation and dysfunction. • At an early stage, patients with DCM may have myocardial fibrosis despite the absence of LGE. • T1 mapping and ECV are efficient methods for early detection of potential myocardial fibrosis. • Increased native T1 and ECV are correlated with left ventricular dilation and dysfunction in LGE-negative DCM patients.

Positive CMR findings are associated with polymorphic ventricle arrhythmias and ECG repolarization changes but not with exercises induced arrhythmias in competitive and non-competitive athletes

Abstract Funding Acknowledgements Type of funding sources: None. Background Cardiac magnetic resonance (CMR) provides an effective contribution for the prevention of sudden cardiac death with its ability to provide accurate information on morpho-functional abnormalities and on myocardial tissue characterization. However, data on its utility in clinical scenario in the competitive athletes are limited to selected cohort of patients with complex arrhythmias. Objective To retrospectively analyze all the CMR performed at our center for evaluating the predictors of positive CMR findings in a large cohort of competitive and non-competitive athletes presenting with different clinical indications. Methods Over a period of 30 months all the CMR performed on athletes aged > 14 years and training for at least 5 hours per week at our Institutes were retrospectively recruited. The following data were also collected: medical history, ECG, echocardiography, exercise testing. CMR were categorized as "positive" or "negative" based on the presence or absence of late gadolinium enhancement (LGE, excluding RV insertion point) and/or morphological and/or functional abnormalities. Predictors of "positive" CMR were explored. Results 503 CMR were recruited and the most frequent indications for CMR were: ventricular arrythmias (n= 213, 42%), ECG abnormalities (n= 140, 28%) followed by echocardiogram abnormalities, symptoms and family history (Figure A). 308 (61%) CMR were "negative" and 195 (39%) "positive" (Figure B). Uncommon ventricular arrythmias did not result associated with positive CMR (p= 0.43), while polymorphic ventricular beats are associated with positive CMR (p= 0.02). Among ECG abnormalities only T-waves inversion, particularly on lateral and infero-lateral leads, were associated with positive CMR (p= 0.04). Conclusion Ventricular arrhythmias represented the most common indication for require a CMR but in almost half the cases, the CMR was negative. Excises induced ventricular arrhythmias is not significantly associated with pathological findings on CMR, while the polymorphic morphology of arrhythmias and the presence of lateral and infero-lateral repolarization abnormalities on ECG were associated with positive CMR.

Electrical markers and arrhythmic risk associated with myocardial fibrosis in mitral valve prolapse.

AimsWe aimed to characterize the substrate of T-wave inversion (TWI) using cardiac magnetic resonance (CMR) and the association between diffuse fibrosis and ventricular arrhythmias (VA) in patients with mitral valve prolapse (MVP).Methods and resultsTWI was defined as negative T-wave ≥0.1 mV in ≥2 adjacent ECG leads. Diffuse myocardial fibrosis was assessed by T1 relaxation time and extracellular volume (ECV) fraction by T1-mapping CMR. We included 162 patients with MVP (58% females, age 50 ± 16 years), of which 16 (10%) patients had severe VA (aborted cardiac arrest or sustained ventricular tachycardia). TWI was found in 34 (21%) patients. Risk of severe VA increased with increasing number of ECG leads displaying TWI [OR 1.91, 95% CI (1.04–3.52), P = 0.04]. The number of ECG leads displaying TWI increased with increasing lateral ECV (26 ± 3% for TWI 0-1leads, 28 ± 4% for TWI 2leads, 29 ± 5% for TWI ≥3leads, P = 0.04). Patients with VA (sustained and non-sustained ventricular tachycardia) had increased lateral T1 (P = 0.004), also in the absence of late gadolinium enhancement (LGE) (P = 0.008).ConclusionsGreater number of ECG leads with TWI reflected a higher arrhythmic risk and higher degree of lateral diffuse fibrosis by CMR. Lateral diffuse fibrosis was associated with VA, also in the absence of LGE. These results suggest that TWI may reflect diffuse myocardial fibrosis associated with VA in patients with MVP. T1-mapping CMR may help risk stratification for VA.

Abstract 12567: Reduced Myocardial Strain is Associated With Myocardial Inflammation and Fibrosis on Cardiovascular Magnetic Resonance Imaging in Collegiate Athletes Recovering From SARS-CoV-2 Infection

Introduction: Myocarditis is an important cause of sudden cardiac death in competitive athletes. There have been reports of myocardial inflammation on cardiovascular magnetic resonance (CMR) in athlete and non-athlete populations after SARS-CoV-2 infection; however, their clinical and functional significance is not known. We sought to investigate the relationship between left ventricular (LV) strain and other CMR markers suggestive of myocardial inflammation or fibrosis. Hypothesis: Reduced myocardial strain is associated with the presence of CMR abnormalities suggestive of inflammation, fibrosis, or necrosis in athletes recovering from SARS-CoV-2 infection. Methods: Collegiate athletes (N = 123) underwent a comprehensive CMR exam including strain encoded (SENC) imaging. We analyzed LV global longitudinal strain (GLS) across five groups defined by the presence or absence of late gadolinium enhancement (LGE), and T1 or T2 abnormalities. Myocarditis diagnosis on CMR required both abnormal T1 or LGE, and abnormal T2, in the same LV segment. Results: We enrolled 11 COVID negative control athletes (Group 1). Among COVID positive athletes, 42 had no abnormalities on CMR (Group 2), 31 had isolated right ventricular insertion point (RVIP) LGE (Group 3), 28 had LGE beyond RVIP (Group 4), and 11 athletes had myocarditis (Group 5). GLS was significantly lower in Groups 3, 4, and 5 compared with negative controls (p<0.05, Figure 1). There was a deterioration in GLS as CMR abnormalities progressed from control athletes to those with LGE and myocarditis. There was no significant difference in LV ejection fraction between the 5 groups. Conclusions: In conclusion, SARS-CoV-2 infection in collegiate athletes leads to subtle abnormalities in cardiac function detected by GLS that correlate with abnormal mapping and LGE suggestive of myocardial inflammation and fibrosis. The clinical significance of these abnormalities remains to be determined.

Prevalence, clinical and instrumental features of left bundle branch block-induced cardiomyopathy: the CLIMB registry.

AimsAlthough increasingly recognized as a distinct pathological entity, left bundle branch block‐induced cardiomyopathy (LBBB‐ICMP) is not included among the possible aetiologies of acquired dilated cardiomyopathies (DCM). While diagnostic criteria have been proposed, its recognition remains principally retrospective, in the presence of clinical and instrumental red flags. We aimed to assess the prevalence and clinical and instrumental features of LBBB‐ICMP in a large cohort of patients with DCM.Methods and resultsWe analysed a cohort of 242 DCM patients from a two‐centre registry. Inclusion criteria were age > 18, non‐ischaemic or non‐valvular DCM, and LBBB on electrocardiogram. LBBB‐ICMP was defined according to previously proposed diagnostic criteria: (i) neither family history nor clinically identifiable potential causes for DCM; (ii) negative genetic testing; (iii) echocardiographic features including non‐severe chamber dilation, normal absolute and relative wall thickness, marked dyssynchrony, and normal right ventricular function; and (iv) absence of late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR). From the entire cohort, we identified 30 subjects (similar in terms of New York Heart Association class I or II in 80% vs. 75%, P = 0.56; QRS width of 150 ± 22 vs. 151 ± 24 ms, P = 0.82; and cardiac remodelling of baseline end‐diastolic diameter 66 ± 8 vs. 65 ± 10 mm, P = 0.53) with a comprehensive dataset including CMR and genetic testing, required to verify the presence of the diagnostic criteria proposed for LBBB‐ICMP. The main characteristics of this subgroup were 73% males, age 45 ± 13 years, left ventricular ejection fraction (LVEF) 30 ± 10%, LGE in 38% of patients, and QRS complex of 150 ± 22 ms. Patients were under guideline‐directed medical therapy, and 57% of them were treated with cardiac resynchronization therapy (CRT). Two patients (6.67%, 50% males, age 53 ± 13 years) fulfilled the diagnostic criteria proposed for LBBB‐ICMP. After a follow‐up of 44 (12–76) months, LVEF was normal and QRS width significantly reduced (from 154 ± 25 to 116 ± 52 ms) in patients with LBBB‐ICMP. Both patients were under optimal medical treatment, and one was implanted with CRT‐D. Neither of the two patients experienced death, malignant ventricular arrhythmia, or heart failure hospitalization at follow‐up.ConclusionsLeft bundle branch block‐induced cardiomyopathy emerges as a distinct pathological entity, promptly identifiable in a minority but not negligible proportion of patients with newly diagnosed DCM and LBBB, using a series of diagnostic criteria including CMR and genetic testing. Further studies are needed to better elucidate the clinical course of LBBB‐ICMP.

Myocardial extracellular volume by T1 mapping: a new marker of arrhythmia in mitral valve prolapse

Abstract Funding Acknowledgements Type of funding sources: None. Background In MVP, MAD has been associated with myocardial replacement fibrosis and arrhythmia, but the importance of interstitial fibrosis remains unknown. We aimed to evaluate the relationship between mitral annular disjunction (MAD) severity and myocardial interstitial fibrosis at the left ventricular (LV) base in patients with mitral valve prolapse (MVP), and to assess the association between severity of interstitial fibrosis and the occurrence of ventricular arrhythmic events Methods Thirty patients with MVP and MAD (MVP-MAD) underwent Cardiac Magnetic Resonance (CMR) with assessment of MAD length, late gadolinium enhancement (LGE), and basal segments myocardial extracellular volume (ECV). The control group included 14 patients with mitral regurgitation but no MAD (MR-NoMAD) and 10 patients with normal CMR (NoMR-NoMAD). Fifteen MVP-MAD patients underwent 24h-Holter monitoring. Results LGE was observed in 47% of MVP-MAD patients and absent in controls. ECV was higher in MVP-MAD (30 ± 3% vs 24 ± 3% MR-NoMAD, p < 0.0001 and vs 24 ± 2% NoMR-NoMAD, p < 0.0001), even in MVP-MAD patients without LGE (29 ± 3% vs 24 ± 3%, p < 0.0001 and vs 24 ± 2%, p < 0.0001, respectively), Fig.1. MAD length was correlated with ECV (rho = 0.61, p = 0.0003), but not with LGE extent. Four patients had history of OHCA; LGE and ECV were equally performant to identify those high-risk patients (area under the ROC curve 0.81 vs 0.83, p = 0.84). Among patients with Holter, 87% had complex ventricular arrhythmia. ECV was above the cut-off value in all while only 53% had LGE. Conclusion Increase in ECV, a marker of interstitial fibrosis, occurs in MVP-MAD even in the absence of LGE, and was correlated with MAD length and OHCA. ECV should be part of the CMR examination of MVP patients in an effort to better assess fibrous remodelling as it may provide additional value beyond the assessment of LGE in the arrhythmic risk stratification.

Left Ventricular Remodeling Following Balloon Mitral Valvuloplasty in Rheumatic Mitral Stenosis: Magnetic Resonance Imaging Study.

Background: Rheumatic heart disease affects primarily cardiac valves, it could involve the myocardium either primarily or secondary to heart valve affection. The influence of balloon mitral valvuloplasty (BMV) on left ventricular function has not been sufficiently studied.Aim: To determine the influence of balloon mitral valvuloplasty (BMV) on both global and regional left ventricular (LV) function.Methods: Thirty patients with isolated rheumatic mitral stenosis (MS) were studied. All patients had cardiac magnetic resonance imaging (CMR) before, 6 months and 1 year after successful BMV. LV volumes, ejection fraction (EF), regional and global LV deformation, and LV late gadolinium enhancement were evaluated.Results: At baseline, patients had median EF of 57 (range: 45–69) %, LVEDVI of 74 (44–111) ml/m2 and LVESVI of 31 (14–57) ml/m2 with absence of late gadolinium enhancement in all myocardial segments. Six months following BMV, there was a significant increase in LV peak systolic global longitudinal strain (GLS) (−16.4 vs. −13.8, p < 0.001) and global circumferential strain (GCS) (−17.8 vs. −15.6, p = 0.002). At 1 year, there was a trend towards decrease in LVESVI (29 ml/m2, p = 0.079) with a significant increase in LV EF (62%, p < 0.001). A further significant increase, compared to 6 months follow up studies, was noticed in GLS (−17.9 vs. −16.4, p = 0.008) and GCS (−19.4 vs. −17.8 p = 0.03).Conclusions: Successful BMV is associated with improvement in global and regional LV systolic strain which continues for up to 1 year after the procedure.

Myocardial extracellular volume by T1 mapping: a new marker of arrhythmia in mitral valve prolapse

ObjectivesWe aimed to evaluate the relationship between mitral annular disjunction (MAD) severity and myocardial interstitial fibrosis at the left ventricular (LV) base in patients with mitral valve prolapse (MVP), and to assess the association between severity of interstitial fibrosis and the occurrence of ventricular arrhythmic events.BackgroundIn MVP, MAD has been associated with myocardial replacement fibrosis and arrhythmia, but the importance of interstitial fibrosis remains unknown.MethodsIn this retrospective study, 30 patients with MVP and MAD (MVP–MAD) underwent cardiovascular magnetic resonance (CMR) with assessment of MAD length, late gadolinium enhancement (LGE), and basal segments myocardial extracellular volume (ECVsyn). The control group included 14 patients with mitral regurgitation (MR) but no MAD (MR-NoMAD) and 10 patients with normal CMR (NoMR-NoMAD). Fifteen MVP–MAD patients underwent 24 h-Holter monitoring.ResultsLGE was observed in 47% of MVP–MAD patients and was absent in all controls. ECVsyn was higher in MVP–MAD (30 ± 3% vs 24 ± 3% MR-NoMAD, p < 0.001 and vs 24 ± 2% NoMR-NoMAD, p < 0.001), even in MVP–MAD patients without LGE (29 ± 3% vs 24 ± 3%, p < 0.001 and vs 24 ± 2%, p < 0.001, respectively). MAD length correlated with ECVsyn (rho = 0.61, p < 0.001), but not with LGE extent. Four patients had history of out-of-hospital cardiac arrest; LGE and ECVsyn were equally performant to identify those high-risk patients, area under the receiver operating characteristic (ROC) curve 0.81 vs 0.83, p = 0.84). Among patients with Holter, 87% had complex ventricular arrhythmia. ECVsyn was above the cut-off value in all while only 53% had LGE.ConclusionIncrease in ECVsyn, a marker of interstitial fibrosis, occurs in MVP–MAD even in the absence of LGE, and was correlated with MAD length and increased risk of out-of-hospital cardiac arrest. ECV should be includedin the CMR examination of MVP patients in an effort to better assess fibrous remodelling as it may provide additional value beyond the assessment of LGE in the arrhythmic risk stratification.

Non-contrast cardiovascular magnetic resonance detection of myocardial fibrosis in Duchenne muscular dystrophy

BackgroundDuchenne muscular dystrophy (DMD) leads to progressive cardiomyopathy. Detection of myocardial fibrosis with late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR) is critical for clinical management. Due to concerns of brain deposition of gadolinium, non-contrast methods for detecting and monitoring myocardial fibrosis would be beneficial.ObjectivesWe hypothesized that native T1 mapping and/or circumferential (εcc) and longitudinal (εls) strain can detect myocardial fibrosis.Methods156 CMRs with gadolinium were performed in 66 DMD boys and included: (1) left ventricular ejection fraction (LVEF), (2) LGE, (3) native T1 mapping and myocardial tagging (εcc-tag measured using harmonic phase analysis). LGE was graded as: (1) presence/absence by segment, slice, and globally; (2) global severity from 0 (no LGE) to 4 (severe); (3) percent LGE using full width half maximum (FWHM). εls and εcc measured using feature tracking. Regression models to predict LGE included native T1 and either εcc-tag or εls and εcc measured at each segment, slice, and globally.ResultsMean age and LVEF at first CMR were 14 years and 54%, respectively. Global εls and εcc strongly predicted presence or absence of LGE (OR 2.6 [1.1, 6.0], p = 0.029, and OR 2.3 [1.0, 5.1], p = 0.049, respectively) while global native T1 did not. Global εcc, εls, and native T1 predicted global severity score (OR 2.6 [1.4, 4.8], p = 0.002, OR 2.6 [1.4, 6.0], p = 0.002, and OR 1.8 [1.1, 3.1], p = 0.025, respectively). εls correlated with change in LGE by severity score (n = 33, 3.8 [1.0, 14.2], p = 0.048) and εcc-tag correlated with change in percent LGE by FWHM (n = 34, OR 0.2 [0.1, 0.9], p = 0.01).ConclusionsPre-contrast sequences predict presence and severity of LGE, with εls and εcc being more predictive in most models, but there was not an observable advantage over using LVEF as a predictor. Change in LGE was predicted by εls (global severity score) and εcc-tag (FWHM). While statistically significant, our results suggest these sequences are currently not a replacement for LGE and may only have utility in a very limited subset of DMD patients.

Comparative study on native T1 value of myocardium between using ConSept and SAX approaches in non-ischemic dilated cardiomyopathy.

T1 mapping can noninvasively quantify the native longitudinal relaxation time (T1 value) of myocardium and provide more information on myocardial fibrosis based on late gadolinium enhancement (LGE). However, the traditional approach of measuring T1 value limits the popularization and application of this technology in clinic because the whole short axis (SAX) of myocardium is required in the regions of interest (ROI). This study aims to evaluate the diagnostic ability of native T1 value obtained by comparison between the midventricular septum (ConSept) and SAX approaches in diffuse myocardial lesions. Retrospective analysis was performed on 38 patients with non-ischemic dilated cardiomyopathy (NIDCM) and 27 healthy controls who underwent T1 mapping and gadolinium delayed enhancement (LGE) scanning on a 3.0T cardiac magnetic resonance (CMR) in Xiangya Hospital of Central South University. Patients with NIDCM were divided into a LGE positive group and a LGE negative group according to the presence or absence of LGE. The native T1 value was measured by the ROI placed in the ConSept and SAX, respectively. The ability to distinguish the impaired myocardium from the healthy myocardium and the native T1 values of the myocardium measured by the 2 approaches were compared between the NIDCM group and the control group. The native T1 values of NIDCM group using ConSept or SAX approach were significantly higher than those in the control group (all P<0.001), and the native T1 values in the LGE positive group were greater than those in the LGE negative group (all P<0.05). There was no significant difference in T1 value of middle, basal, and apical layer between the ConSept approach and SAX approach (all P>0.05). ConSept and SAX approaches had a good consistency [concordance correlation coefficient (CCC)=0.954]. Comparing to the SAX approach, ConSept approach is a simple and equivalent method to measure the native T1 value of myocardium and is suitable for clinical application.