Early or deferred cardiovascular magnetic resonance after ST-segment-elevation myocardial infarction for effective risk stratification

AIMS

In ST-segment-elevation myocardial infarction (STEMI), cardiovascular magnetic resonance (CMR) holds the potentiality to improve risk stratification in addition to Thrombolysis in Myocardial Infarction (TIMI) risk score. Nevertheless, the optimal timing for CMR after STEMI remains poorly defined. We aim at comparing the prognostic performance of three stratification strategies according to the timing of CMR after STEMI.

METHODS AND RESULTS

The population of this prospective registry-based study included 492 reperfused STEMI patients. All patients underwent post-reperfusion (median: 4 days post-STEMI) and follow-up (median: 4.8 months post-STEMI) CMR. Left ventricular (LV) volumes, function, infarct size, and microvascular obstruction extent were quantified. Primary endpoint was a composite of all-death and heart failure (HF) hospitalization. Baseline-to-follow-up percentage increase of LV end-diastolic (EDV; ΔLV-EDV) ≥20% or end-systolic volumes (ESV; ΔLV-ESV) ≥15% were tested against outcome. Three multivariate models were developed including TIMI risk score plus early post-STEMI (early-CMR) or follow-up CMR (deferred-CMR) or both CMRs parameters along with adverse LV remodelling (paired-CMRs). During a median follow-up of 8.3 years, the primary endpoint occurred in 84 patients (47 deaths; 37 HF hospitalizations). Early-CMR, deferred-CMR, and paired-CMR demonstrated similar predictive value for the primary endpoint (C-statistic: 0.726, 0.728, and 0.738, respectively; P = 0.663). ΔLV-EDV ≥20% or ΔLV-ESV ≥15% were unadjusted outcome predictors (hazard ratio: 2.020 and 2.032, respectively; P = 0.002 for both) but lost their predictive value when corrected for other covariates in paired-CMR model.

CONCLUSION

In STEMI patients, early-, deferred-, or paired-CMR were equivalent stratification strategies for outcome prediction. Adverse LV remodelling parameters were not independent prognosticators.

Pulmonary blood volume index as a quantitative biomarker of haemodynamic congestion in hypertrophic cardiomyopathy

Aims 

The non-invasive assessment of left ventricular (LV) diastolic function and filling pressure in hypertrophic cardiomyopathy (HCM) is still an open issue. Pulmonary blood volume index (PBVI) by cardiovascular magnetic resonance (CMR) has been proposed as a quantitative biomarker of haemodynamic congestion. We aimed to assess the diagnostic accuracy of PBVI for left atrial pressure (LAP) estimation in patients with HCM.

Methods and results 

We retrospectively identified 69 consecutive HCM outpatients (age 58 ± 11 years; 83% men) who underwent both transthoracic echocardiography (TTE) and CMR. Guideline-based detection of LV diastolic dysfunction was assessed by TTE, blinded to CMR results. PBVI was calculated as the product of right ventricular stroke volume index and the number of cardiac cycles for a bolus of gadolinium to pass through the pulmonary circulation as assessed by first-pass perfusion imaging. Compared to patients with normal LAP, patients with increased LAP showed significantly larger PBVI (463 ± 127 vs. 310 ± 86 mL/m², P < 0.001). PBVI increased progressively with worsening New York Heart Association functional class and echocardiographic stages of diastolic dysfunction (P < 0.001 for both). At the best cut-off point of 413 mL/m², PBVI yielded good diagnostic accuracy for the diagnosis of LV diastolic dysfunction with increased LAP [C-statistic = 0.83; 95% confidence interval (CI): 0.73–0.94]. At multivariable logistic regression analysis, PBVI was an independent predictor of increased LAP (odds ratio per 10% increase: 1.97, 95% CI: 1.06–3.68; P = 0.03).

Conclusion 

PBVI is a promising CMR application for assessment of diastolic function and LAP in patients with HCM and may serve as a quantitative marker for detection, grading, and monitoring of haemodynamic congestion.

Prevalence and prognostic impact of nonischemic late gadolinium enhancement in stress cardiac magnetic resonance

AIM

To assess the prevalence and prognostic significance of NI-LGE in patients undergoing stress-CMR.

METHODS

Stress-CMR with either dipyridamole or adenosine was performed in 283 patients (228 men, 81%) including perfusion imaging, wall motion evaluation and LGE. Follow-up was completed in all enrolled patients (median time: 1850 days; interquartile range: 1225-2705 days). Composite endpoint included cardiac death, ventricular tachycardia, myocardial infarction, stroke, hospitalization for cardiac cause and coronary revascularization performed beyond 90 days from stress-CMR scans.

RESULTS

One hundred and twelve patients (40%) had negative LGE (no-LGE), 140 patients (49%) I-LGE and 31 patients (11%) NI-LGE. Twenty-five events occurred in the no-LGE group, 68 in I-LGE and 11 in the NI-LGE group. On survival curves, patients with NI-LGE had worse prognosis than patients with no-LGE regardless of the presence of inducible perfusion defects. No significant prognostic differences were found between I-LGE and NI-LGE.

CONCLUSION

NI-LGE can be detected in 11% of patients during stress-CMR providing a diagnosis of nonischemic cardiac disease. Patients with NI-LGE have worse prognosis than those with no-LGE.

Post-mortem CMR in a model of sudden death due to myocardial ischemia: validation with connexin-43

OBJECTIVES

We sought to evaluate the effectiveness of post-mortem cardiac magnetic resonance (PM-CMR) for the identification of myocardial ischemia as cause of sudden cardiac death (SCD) when the time interval between the onset of ischemia and SCD is ≤ 90 min.

METHODS

PM-CMR was performed in 8 hearts explanted from pigs with spontaneous death caused by occlusion of the left anterior descending coronary artery: 4 with SCD after ≤ 40 min of coronary occlusion and 4 between 40 and 90 min. PM-CMR included conventional T1 and T2-weighted image and T1, T2, and T2* mapping techniques. Imaging data were compared and validated with immunohistochemical evaluation of the altered proportion and redistribution of phosphorylated versus non-phosphorylated connexin 43 (CX43 and npCX43, respectively), an established molecular marker of myocardial ischemia.

RESULTS

At T2-weighted images, the ischemic core was hypointense (core/remote ratio 0.67 ± 0.11) and surrounded by and hyperintense border zone. Compared to remote myocardium, the ischemic core had higher T1 (p = 0.0008), and lower T2 (p = 0.007) and T2* (p = 0.002). Cytoplasmatic npX43 and the npCX43/CX43 ratio were significantly higher in animals deceased > 40 min than in others.

CONCLUSION

PM-CMR can reliably detect early signs of myocardial damage induced by ischemia, based on conventional pulse sequences complemented by a novel ad hoc application of quantitative mapping techniques.

KEY POINTS

• Post-mortem MRI may help to understand cause of sudden cardiac death. • Post-mortem MRI allows detection of signs of myocardial ischemia as cause of sudden cardiac death within 90 and 40 min following coronary occlusion as demonstrated in a pig model of myocardial ischemia. • Signs of myocardial ischemia using conventional and mapping MRI technique are associated with the immunohistochemical changes of phosphorylated and dephosphorylated connexin-43 which is an established molecular marker of myocardial ischemia.

Prognostic Role of Left Ventricular Intramyocardial Fatty Metaplasia in Patients With Previous Myocarditis (MYOFAT Study)

Left ventricular intramyocardial fat (LV-IMF) is often found in patients with previous irreversible myocardial damage and may be detected by cardiac magnetic resonance (CMR). No data are currently available about the prevalence of LV-IMF in patients with previous myocarditis. Our aim was to assess the prevalence of LV-IMF in patients with previous myocarditis by repeating after >3 years a follow-up CMR examination and to evaluate its clinical and prognostic role. Patients with clinical suspected myocarditis who underwent CMR within the first week from the onset of their symptoms and underwent repeated CMR were enrolled. LV-IMF was detected as areas of left ventricular intramyocardial "India ink" black boundary with or without a hyperintense core. Overall, in 235 patients with a definitive diagnosis of acute myocarditis, CMR was repeated after a median of 4 (3 to 6) years from symptom onset. LV-IMF positive patients (n = 35, 15%) presented greater ventricular volumes and more frequently a mid-wall late gadolinium enhancement than those without LV-IMF (both p < 0.05). Patients presenting major cardiac events (sudden cardiac deaths, resuscitated cardiac arrest, and appropriate implantable cardioverter-defibrillator-firing) at follow-up had a greater prevalence of LV-IMF than those without (55% vs 11%, p < 0.001). Patients with LV-IMF had a higher incidence myocarditis relapse (27% vs 9%, p = 0.003) and a greater risk of major cardiac events (p < 0.0001) than those without. At logistic regression analysis, LV-IMF was an independent predictor of major cardiac events. In conclusion, LV-IMF is not an uncommon finding in patients with previous myocarditis and is associated with worse ventricular remodeling and prognosis.

Appropriate use criteria for cardiovascular magnetic resonance imaging (CMR): SIC-SIRM position paper part 1 (ischemic and congenital heart diseases, cardio-oncology, cardiac masses and heart transplant)

Cardiac magnetic resonance (CMR) has emerged as new mainstream technique for the evaluation of patients with cardiac diseases, providing unique information to support clinical decision-making. This document has been developed by a joined group of experts of the Italian Society of Cardiology and Italian society of Radiology and aims to produce an updated consensus statement about the current state of technology and clinical applications of CMR. The writing committee consisted of members and experts of both societies who worked jointly to develop a more integrated approach in the field of cardiac radiology. Part 1 of the document will cover ischemic heart disease, congenital heart disease, cardio-oncology, cardiac masses and heart transplant.

Morphologies and prognostic significance of left ventricular volume/time curves with cardiac magnetic resonance in patients with non-ischaemic heart failure and left bundle branch block

Patients with non-ischaemic systolic heart failure (HF) and left bundle branch block (LBBB) can display a wide or narrow pattern (WP/NP) of the systolic phase of the left ventricular (LV) volume/time (V/t) curve in cardiac magnetic resonance (CMR). The clinical and prognostic significance of these patterns is unknown. Consecutive patients with non-ischaemic HF, LV ejection fraction < 50% and LBBB underwent 1.5 T CMR. Maximal dyssynchrony time (time between the earliest and latest end-systolic peaks), systolic dyssynchrony index (standard deviation of times to peak volume change), and contractility index (maximum rate of change of pressure-normalized stress) were calculated. The endpoint was a composite of cardiovascular death, HF hospitalization, and appropriate defibrillator shock. NP was found in 29 and WP in 72 patients. WP patients had higher volumes and NT-proBNP, and lower LVEF. WP patients had a longer maximal dyssynchrony time (absolute duration: 192 ± 80 vs. 143 ± 65 ms, p < 0.001; % of RR interval: 25 ± 11% vs. 8 ± 4%, p < 0.001), a higher systolic dyssynchrony index (13 ± 4 vs. 7 ± 3%, p < 0.001), and a lower contractility index (2.6 ± 1.2 vs 3.2 ± 1.7, p < 0.05). WP patients had a shorter survival free from the composite endpoint regardless of age, NT-proBNP or LVEF. Nonetheless, WP patients responded more often to cardiac resynchronization therapy (CRT) than those with NP (24/28 [86%] vs. 1/11 [9%] responders, respectively; p < 0.001). In patients with non-ischaemic systolic HF and LBBB, the WP of V/t curves identifies a subgroup of patients with greater LV dyssynchrony and worse outcome, but better response to CRT.

Cardiovascular magnetic resonance: What clinicians should know about safety and contraindications

Cardiovascular magnetic resonance (MR) is a multiparametric, non-ionizing, non-invasive imaging technique, which represents the imaging gold standard to study cardiac anatomy, function and tissue characterization. Faced with a wide range of clinical application, in this review we aim to provide a comprehensive guide for clinicians about MR safety, contraindications and image quality. Starting from the physical interactions of the static magnetic fields, gradients and radiofrequencies with the human body, we will describe the most common metal and electronic devices which are allowed (MR-safe), allowed under limited conditions (MR-conditional) or contraindicated (MR-unsafe). Moreover, some conditions potentially affecting image quality and patient comfort will be mentioned, including arrhythmias, claustrophobia, and poor breath-hold capacity. Finally, we will discuss the pharmacodynamics and pharmacokinetics of current gadolinium-based contrast agents, their contraindications and their potential acute and chronic adverse effects, as well as the safety issue concerning the use of vasodilating/inotropic agents in stress cardiac MR.

Prognostic Impact of Late Gadolinium Enhancement by Cardiovascular Magnetic Resonance in Myocarditis: A Systematic Review and Meta-Analysis

BACKGROUND

Patients with acute myocarditis (AM) are at increased risk of adverse cardiac events after the index episode. Late gadolinium enhancement (LGE) detected by cardiovascular magnetic resonance in patients with AM plays an important diagnostic role, but its prognostic significance remains unresolved. This systematic review and meta-analysis sought to assess the prognostic implications of cardiovascular magnetic resonance-derived LGE in patients with AM.

METHODS

Data search was conducted from inception through February 28, 2020, using the following Medical Subject Heading terms: Myocarditis, CMR, Magnetic Resonance Imaging, Magnetic Resonance. From 2422 articles retrieved, we selected 11 studies reporting baseline cardiovascular magnetic resonance assessment and long-term clinical follow-up in patients with AM. Hazard ratios and CIs for a combined clinical end point were recorded for LGE presence, extent (>2 segments or >10% of left ventricular [LV] mass or >17g) and location (anteroseptal versus non-anteroseptal). A combined end point comprised all-cause mortality, cardiac mortality, and major adverse cardiovascular events. Hartung and Knapp correction improved robustness of the results. Prespecified sensitivity analyses explored potential sources of heterogeneity. The meta-analysis was conducted according to the Meta-analysis of Observational Studies in Epidemiology guidelines.

RESULTS

LGE presence (pooled hazard ratios, 3.28 [95% CIs, 1.69-6.39], P<0.001 [95% CIs, 1.33-8.11] after Hartung and Knapp correction) and anteroseptal LGE (pooled-hazard ratios, 2.58 [95% CIs, 1.87-3.55], P<0.001 [95% CIs, 1.64-4.06] after Hartung and Knapp correction) were associated with an increased risk of the combined end point. Extensive LGE was associated with worse outcomes (pooled-hazard ratios, 1.96 [95% CIs, 1.08-3.56], P=0.027), but this association was not confirmed after Hartung and Knapp correction (95% CIs, 0.843-4.57).

CONCLUSIONS

LGE presence and anteroseptal location at baseline cardiovascular magnetic resonance are important independent prognostic markers that herald an increased risk of adverse cardiac outcomes in patients with AM. Registration: https://www.crd.york.ac.uk/PROSPERO/ Unique identifier: CRD42019146619.

70 Deep learning to diagnose cardiac amyloidosis from cardiac magnetic resonance findings

Aims

Cardiac magnetic resonance (CMR) is part of the diagnostic work-up for cardiac amyloidosis (CA). Deep learning (DL) is an application of artificial intelligence that may allow to automatically analyze CMR findings and establish the likelihood of CA.

Methods and results

1.5 T CMR was performed in 187 subjects with suspected CA (n = 92, 49% with unexplained left ventricular—LV—hypertrophy; n = 95, 51% with blood dyscrasia and suspected light-chain amyloidosis). Patients were randomly assigned to the training (n = 121, 65%), validation (n = 28, 15%), and testing subgroups (n = 38, 20%). Short axis (SA), 2-chamber (2 C), 4-chamber (4 C) late gadolinium enhancement (LGE) images were evaluated by 3 networks (DL algorithms). The tags “amyloidosis present” or “absent” were attributed when the average probability of CA from the 3 networks was ≥50% or &lt; 50%, respectively. The DL strategy was compared to a machine learning (ML) algorithm considering all manually extracted features (LV volumes, mass and function, LGE pattern, early blood-pool darkening, pericardial and pleural effusion, etc.), to reproduce exam reading by an experienced operator. The DL strategy displayed good diagnostic accuracy (84%), with an area under the curve (AUC) of 0.96. The precision (positive predictive value), recall score (sensitivity), and F1 score (a measure of test accuracy) were 78%, 94%, and 86% respectively. A ML algorithm considering all CMR features had a similar diagnostic yield to DL strategy (AUC 0.93 vs. 0.96; p = 0.45).

Conclusion

A DL approach evaluating LGE acquisitions displayed a similar diagnostic performance for CA to a ML-based approach, which simulates CMR reading by experienced operators.

Deep learning to diagnose cardiac amyloidosis from cardiovascular magnetic resonance

BACKGROUND

Cardiovascular magnetic resonance (CMR) is part of the diagnostic work-up for cardiac amyloidosis (CA). Deep learning (DL) is an application of artificial intelligence that may allow to automatically analyze CMR findings and establish the likelihood of CA.

METHODS

1.5 T CMR was performed in 206 subjects with suspected CA (n = 100, 49% with unexplained left ventricular (LV) hypertrophy; n = 106, 51% with blood dyscrasia and suspected light-chain amyloidosis). Patients were randomly assigned to the training (n = 134, 65%), validation (n = 30, 15%), and testing subgroups (n = 42, 20%). Short axis, 2-chamber, 4-chamber late gadolinium enhancement (LGE) images were evaluated by 3 networks (DL algorithms). The tags "amyloidosis present" or "absent" were attributed when the average probability of CA from the 3 networks was ≥ 50% or < 50%, respectively. The DL strategy was compared to a machine learning (ML) algorithm considering all manually extracted features (LV volumes, mass and function, LGE pattern, early blood-pool darkening, pericardial and pleural effusion, etc.), to reproduce exam reading by an experienced operator.

RESULTS

The DL strategy displayed good diagnostic accuracy (88%), with an area under the curve (AUC) of 0.982. The precision (positive predictive value), recall score (sensitivity), and F1 score (a measure of test accuracy) were 83%, 95%, and 89% respectively. A ML algorithm considering all CMR features had a similar diagnostic yield to DL strategy (AUC 0.952 vs. 0.982; p = 0.39).

CONCLUSIONS

A DL approach evaluating LGE acquisitions displayed a similar diagnostic performance for CA to a ML-based approach, which simulates CMR reading by experienced operators.

Electromechanical dissociation of left atrium in patients with Cardiac Amyloidosis by Magnetic Resonance: Prognostic and clinical correlates

OBJECTIVES

Left atrial (LA) function is an important marker of hemodynamic status in cardiac amyloidosis (CA), and its characterization may provide relevant prognostic information. We sought to assess the prevalence and prognostic impact of LA dysfunction by cardiac magnetic resonance (CMR) in patients with CA.

METHODS

We performed CMR in 80 consecutive patients with CA, including 38 with AL (47%) and 42 with ATTR (53%). LA function was assessed by acquiring short axis cine steady-state free precession (SSFP) covering the entire chamber. The atrial emptying fraction (AEF) was calculated as the ratio between the difference of LA maximal and minimal volume to LA maximal volume, expressed as percentage. Severe atrial dysfunction was defined as AEF ≤ 14%.

RESULTS

Mean AEF was 18% (13-35%). Overall, AEF ≤ 14% was present in 19 patients (24%), including 21% of those in sinus rhythm (SR) with no history of atrial fibrillation (AF). After a median of 3 years (IQR 2-4), 36 patients (44%) died of cardiac causes. Patients with AEF ≤ 14% showed increased cardiac mortality, with an independent OR of 4.2 (95 IC 2.1-8.2, P < 0.0001). Of note, AEF ≤ 14% was the stronger independent predictor of cardiac death. Patients in SR with AEF ≤ 14% had worse outcome than those with AF.

CONCLUSIONS

Severe impairment of LA contractile function was present in three-quarters of patients with CA, and was prevalent irrespective of CA etiology, both in the presence and absence of AF. Severe LA dysfunction was associated with an independent 4-fold increase in risk for cardiac death at three years.

Lung magnetic resonance imaging in systemic sclerosis: a new promising approach to evaluate pulmonary involvement and progression

INTRODUCTION/OBJECTIVES

Interstitial lung disease (ILD) is frequent and highly disabling in systemic sclerosis (SSc). Magnetic resonance imaging (MRI) is not routinely used to evaluate the lung, due to poorer spatial resolution compared to high-resolution computed tomography (HRCT). We aimed to compare lung MRI signal with HRCT and evaluate the role of MRI in predicting ILD progression.

METHODS

Thirty SSc patients underwent lung MRI and HRCT. STIR and T1 mapping sequences were acquired before and after gadolinium injection. Patients were classified as normal (group 1 with normal HRCT and MRI), discordant (group 2 without ILD signs on HRCT but areas of hyperintensity on MRI), and abnormal (group 3 with ILD signs on HRCT and areas of hyperintensity on MRI). Patients were followed up for ILD progression.

RESULTS

Mean STIR and T1 values were different between the three groups (p < 0.0001). STIR values correlated with HRCT score (R = 0.79, p < 0.0001), lung ultrasound B-lines (R = 0.73, p < 0.0001), and %DLco (R = - 0.63, p = 0.0001). Nine events were recorded during a follow-up of 25 ± 20 months. Continuous STIR values were independently associated with events (HR 1.018; CI 1.005-1.031, p = 0.005). A STIR value >90 ms discriminated patients at a higher risk of worsening pulmonary involvement (HR 8.80; CI 1.81-42.74; p < 0.007).

CONCLUSIONS

Lung MRI can detect SSc-related ILD, with good correlations with other ILD markers. STIR values, independently of HRCT appearance, may predict worsening lung involvement. Lung MRI, although very preliminary, is a promising tool that in a near future could help selecting patients for an early treatment of SSc-related ILD and a more appropriate use of HRCT. Key points • Lung MRI has the potential to differentiate inflammation-predominant versus fibrosis-predominant lesions, but it is not currently used in routine clinical practice to assess SSc-related ILD. • Lung MRI STIR and T1 values are significantly different between patients with and without SSc-related ILD. STIR values, independently of HRCT appearance, are also able to predict worsening lung involvement over time. • These preliminary data suggest that, in a near future, MRI could support the choice for an early treatment of SSc-related ILD, as well as a more appropriate use of HRCT.

Iatrogenic pulmonary artery dissection in patient with ostium secundum interatrial septum defect

Pulmonary artery dissection is a rare and lethal condition. Few cases are reported in the literature, and most are derived from autopsies. In most cases, pulmonary artery dissection is a complication of chronic pulmonary hypertension leading to pulmonary artery aneurysm but there are other causes. We describe a case of iatrogenic pulmonary artery dissection in an elderly patient with ostium secundum defect. In particular, we describe the role of cardiac magnetic resonance in making this diagnosis and guiding future therapeutic decisions.

Late gadolinium enhancement role in arrhythmic risk stratification of patients with LMNA cardiomyopathy: results from a long-term follow-up multicentre study

Aims

We aimed at addressing the role of late gadolinium enhancement (LGE) in arrhythmic risk stratification of LMNA-associated cardiomyopathy (CMP).

Methods and results

We present data from a multicentre national cohort of patients with LMNA mutations. Of 164 screened cases, we finally enrolled patients with baseline cardiac magnetic resonance (CMR) including LGE sequences [n = 41, age 35 ± 17 years, 51% males, mean left ventricular ejection fraction (LVEF) by echocardiogram 56%]. The primary endpoint of the study was follow-up (FU) occurrence of malignant ventricular arrhythmias [MVA, including sustained ventricular tachycardia (VT), ventricular fibrillation, and appropriate implantable cardioverter-defibrillator (ICD) therapy]. At baseline CMR, 25 subjects (61%) had LGE, with non-ischaemic pattern in all of the cases. Overall, 23 patients (56%) underwent ICD implant. By 10 ± 3 years FU, eight patients (20%) experienced MVA, consisting of appropriate ICD shocks in all of the cases. In particular, the occurrence of MVA in LGE+ vs. LGE− groups was 8/25 vs. 0/16 (P = 0.014). Of note, no significant differences between LGE+ and LGE− patients were found in currently recognized risk factors for sudden cardiac death (male gender, non-missense mutations, baseline LVEF &lt;45% and non-sustained VT), all P-value &gt;0.05.

Conclusions

In LMNA-CMP patients, LGE at baseline CMR is significantly associated with MVA. In particular, as suggested by this preliminary experience, the absence of LGE allowed to rule-out MVA at 10 years mean FU.

Comparison of different prediction models for the indication of implanted cardioverter defibrillator in patients with arrhythmogenic right ventricular cardiomyopathy

Aims

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is associated with a high risk of sudden cardiac death. Three different prediction models for the indication of implanted cardioverter defibrillator (ICD) are now available: the 5 year ARVC risk score, the International Task Force Consensus (ITFC) criteria, and the Heart Rhythm Society (HRS) criteria. We compared these three prediction models in a validation cohort of patients with definite ARVC.

Methods and results

In a cohort of 140 patients with definite ARVC, the 5 year ARVC risk score and the ITFC and HRS criteria were compared for the prediction of a major combined endpoint of sudden cardiac death, appropriate ICD intervention, resuscitated cardiac arrest, and sustained ventricular tachycardia. During the follow‐up, 65 major events occurred. The 5 year ARVC risk score with a threshold >10%, derived from the maximally selected rank statistic, predicted 62 (95%) events [odds ratio (OR) 9.1, 95% confidence interval (CI) 2.6–32, P = 0.0006], the ITFC criteria 53 (81%, OR 4.8, 95% CI 2.2–10.3, P = 0.0001), and the HRS criteria 29 (45%, OR 4.2, 95% CI 1.9–9.3, P = 0.0003). At the analysis of decision curve for ICD implantation, a 5 year ARVC risk score >10% showed a greater net benefit than the ITFC and HRS criteria over a wide range of threshold probability of events. Finally, at multivariate analysis, the 5 year ARVC risk score >10% was the only independent predictor of major events.

Conclusions

The 5 year score with a threshold of >10% was more effective for predicting events than the ITFC and HRS criteria.

The Multi-modality Cardiac Imaging Approach to Cardiac Sarcoidosis

BACKGROUND

Sarcoidosis is a multisystem granulomatous disease with a neglected but high prevalence of life-threatening cardiac involvement.

DISCUSSION

The clinical presentation of Cardiac Sarcoidosis (CS) depends upon the location and extent of the granulomatous inflammation, with left ventricular free wall the most common location followed by interventricular septum. The lack of a diagnostic gold standard and the unpredictable risk of sudden cardiac death pose serious challenges for the validation of accurate and effective screening test and the management of the disease. In the last few years advanced cardiac imaging modalities such as Cardiac Magnetic Resonance (CMR) and Positron Emission Tomography (PET) have significantly improved our knowledge and understanding of CS, and have also contributed in risk stratification, assessment of inflammatory activity and therapeutic monitoring of the disease.

CONCLUSION

In this review, we will discuss the state of the art in the diagnosis of CS focusing on the role and importance of multi-modality cardiac imaging.

Late Gadolinium Enhancement-Dispersion Mapping: A New Magnetic Resonance Imaging Technique to Assess Prognosis in Patients With Hypertrophic Cardiomyopathy and Low-Intermediate 5-Year Risk of Sudden Death

BACKGROUND

Late gadolinium enhancement (LGE) is an important prognostic marker in hypertrophic cardiomyopathy and an extent >15% it is associated with high risk of sudden cardiac death. We proposed a novel method, the LGE-dispersion mapping, to assess heterogeneity of scar, and evaluated its prognostic role in patients with hypertrophic cardiomyopathy.

METHODS

One hundred eighty-three patients with hypertrophic cardiomyopathy and a low- or intermediate 5-year risk of sudden cardiac death underwent cardiac magnetic resonance imaging. A parametric map was generated from each LGE image. A score from 0 to 8 was assigned at every pixel of these maps, indicating the number of the surrounding pixels having different quality (nonenhancement, mild-enhancement, or hyperenhancement) from the central pixel. The Global Dispersion Score (GDS) was calculated as the average score of all the pixels of the images.

RESULTS

During a median follow-up time of 6 (25th-75th, 4-10) years, 22 patients had hard cardiac events (sudden cardiac death, appropriate implantable cardioverter-defibrillator therapy, resuscitated cardiac arrest, and sustained ventricular tachycardia). Kaplan-Meier analysis showed that patients with GDS>0.86 had worse prognosis than those with lower GDS (P<0.0001). GDS>0.86 was the only independent predictor of cardiac events (hazard ratio, 9.9 [95% CI, 2.9-34.6], P=0.0003). When compared with LGE extent >15%, GDS improved the classification of risk in these patients (net reclassification improvement, 0.39 [95% CI, 0.11-0.72], P<0.019).

CONCLUSIONS

LGE-dispersion mapping is a marker of scar heterogeneity and provides a better risk stratification than LGE presence and its extent in patients with hypertrophic cardiomyopathy and a low-intermediate 5-year risk of sudden cardiac death.

Myocardial salvage is increased after sympathetic renal denervation in a pig model of acute infarction

RATIONALE

Despite advances in treatment of acute myocardial infarction (AMI), many patients suffer significant myocardial damage with cardiac dysfunction. Sympathetic renal denervation (RD) may reduce adrenergic activation following AMI.

OBJECTIVE

To investigate the potential role of RD limiting myocardial damage and remodeling when performed immediately after AMI.

METHODS AND RESULTS

Sixteen farm pigs underwent 90 min left anterior descending artery balloon occlusion. Eight pigs underwent RD immediately after reperfusion. LV function, extent of myocardium at risk, and myocardial necrosis were quantified by cardiac magnetic resonance 5 and 30 days after AMI. ¹²³I-MIBG scintigraphy was performed 31 days after AMI to image myocardial sympathetic innervation. Heart norepinephrine was quantified (from necrotic, border and remote zone). RD and control did not differ in myocardium at risk extent (59 ± 9 vs 55 ± 11% of LV mass) at 5 days. At 30 days CMR, RD pigs had smaller necrotic areas than control as assessed by gadolinium delay enhancement (18 ± 7 vs 30 ± 12% of LV mass, p = 0.021) resulting in improved myocardial salvage index (60 ± 11 vs 44 ± 27%, p < 0.001). RD pigs had higher cardiac output (3.7 ± 0.8 vs 2.66 ± 0.7 L/min, p < 0.001) and lower LV end diastolic volume (98 ± 16 vs 113 ± 31 ml, p = 0.041). ¹²³I-MIBG defect extension was smaller in RD than control (60 ± 28 vs 78 ± 17%, p < 0.05) with significant reduction in the difference between innervation and perfusion defects (25 ± 12 vs 36 ± 30%, p = 0.013). NE content from necrotic area (238; IQR 464 vs 2546; IQR 1727 ng/g in RD and control, respectively, p < 0.001) and from border zone (295; IQR 264 vs 837; IQR 207 in RD and control, respectively, p = 0.031) was significantly lower in RD than control.

CONCLUSIONS

RD results in increased myocardial salvage and better cardiac function, when performed immediately after AMI. Reduction of sympathetic activation with preservation of cardiac sympathetic functionality warranted by RD may sustain these effects.

Diphosphonate single-photon emission computed tomography in cardiac transthyretin amyloidosis

BACKGROUND

Planar diphosphonate scintigraphy is an established diagnostic tool for amyloid transthyretin (ATTR) cardiomyopathy. Characterization of the amyloid burden up to the segmental level by single photon emission computed tomography (SPECT) has not been evaluated so far.

METHODS

Data from consecutive patients undergoing cardiac ^99mTc-hydroxymethylene diphosphonate (^99mTc-HMDP) SPECT and diagnosed with ATTR cardiomyopathy at a tertiary referral center from June 2016 to April 2019 were collected.

RESULTS

Thirty-eight patients were included (median age 81 years, 79% men, 92% with wild-type ATTR). In patients with Perugini score 1, the most intense diphosphonate regional uptake was found in septal segments, particularly in infero-septal segments. Among patients scoring 2, the amyloid burden in the septum became more significant, and extended to inferior and apical segments. Finally, patients scoring 3 displayed an intense and widespread tracer uptake. All patients with Perugini score 1 had LGE in at least one antero-septal, one infero-septal, and one infero-lateral segment. All patients with score 2 displayed LGE in infero-septal, inferior, and infero-lateral segments. LGE became extensive in patients scoring 3, with all patients having at least one LGE-positive segment in each region.

CONCLUSIONS

When assimilating different Perugini grades to evolutive stages of the disease, amyloid deposition seem to progress from the septum to the inferior wall and then to the other regions and from the basis to the apex. The potential of segmental analysis might be particularly relevant in patients with very limited cardiac uptake at planar scintigraphy (Perugini score 1).

Left ventricular noncompaction, morphological, and clinical features for an integrated diagnosis

The presence of myocardial noncompaction (NC), regardless of the criterion used, does not identify cardiomyopathy per se. The distinction between a morphological variant and the presence of an NC cardiomyopathy is challenging. However, thanks to larger cohorts of patients and longer periods of follow-up, better clinical characterization and prognostic evaluation are becoming available. Indeed, the physician is required to integrate the evidence of NC with the clinical history of the patient, which is supplemented by necessary advanced instrumental investigations before a definite diagnosis of NC cardiomyopathy can be made. Therefore, we extensively revised the current literature in order to help the clinicians to identify clinical features which are pivotal supporting diagnostic element for the correct recognition of Left ventricular noncompaction cardiomyopathy and thus highlighting the difference between a form of cardiomyopathy and a mere intraventricular hypertrabeculation.

Biventricular Reference Values by Body Surface Area, Age, and Gender in a Large Cohort of Well-Treated Thalassemia Major Patients Without Heart Damage Using a Multiparametric CMR Approach

BACKGROUND

Cardiac MRI plays a critical role in the management of thalassemic patients. No accurate biventricular reference values are available.

PURPOSE

To establish the ranges for normal left ventricular (LV) and right ventricular (RV) volumes and ejection fraction (EF) and LV mass normalized to body surface area (BSA), age, and gender in a large cohort of well-treated beta-thalassemia major (β-TM) patients without heart damage using a multiparametric MRI.

STUDY TYPE

Retrospective/cohort study.

POPULATION

In all, 251 β-TM patients with no known risk factors or cardiac disease, normal electrocardiogram, no macroscopic myocardial fibrosis, and all cardiac segments with T₂ * ≥20 msec, and 246 healthy subjects.

FIELD STRENGTH/SEQUENCE

1.5T/cine steady-state free precession (SSFP), gradient-echo T₂ *, late gadolinium enhancement (LGE) images.

ASSESSMENT

Biventricular end-diastolic volume, end-systolic volume, stroke volume, and LV mass were normalized to BSA (EDVI, ESVI, SVI).

STATISTICAL TESTS

Comparisons between the two groups was performed with two-samples t-test or Wilcoxon's signed rank test. For more than two groups, one-way analysis of variance (ANOVA) or a Kruskal-Wallis test were applied.

RESULTS

Compared to controls, males with β-TM showed significantlt higher LVEDVI in all the age groups, while for the other volumes the difference was significant only within one or more age groups. In females the volumes were comparable between β-TM patients and healthy subjects in all the age groups. In the male β-TM population we found a significant effect of age on LVEDVI (P = 0.017), LVESVI (P = 0.001), RVESVI (P = 0.029), and RVEF (P = 0.031), while for females none of the biventricular parameters were significantly different among the age groups (LVEDVI: P = 0.614; LVESVI: P = 0.449; LVSVI: P = 0.186; LV mass index: P = 0.071; LVEF: P = 0.059; RVEDVI: P = 0.374; RVESVI: P = 0.180; RVSVI: P = 0.206; RVEF: P = 0.057). In β-TM patients all biventricular volume indexes as well as the LV mass index were significantly larger in males than in females (P < 0.0001 in all cases). The LV and the RV EF were comparable between the sexes (P = 0.568 and P = 0.268, respectively).

DATA CONCLUSION

Appropriate "normal" reference ranges normalized to BSA, sex, and age are recommended to avoid misdiagnosis of cardiomyopathy in β-TM patients.

LEVEL OF EVIDENCE

4 TECHNICAL EFFICACY STAGE: 2.