Relationships between plasma cytokine balance and cardiac magnetic resonance imaging in long-term post-COVID follow-up: a cross-sectional preliminary study

Background

COVID-19 infection can lead to a constellation of long-lasting post-infectious sequelae, including myocardial dysfunction, whose outcome is strongly affected by a fine-tuned balance between pro- and anti-inflammatory systemic immune responses. Plasma cytokines are key mediators of this immunological balance. In this preliminary study we evaluated the cross-sectional association between the circulating levels of the main pro- and anti-inflammatory cytokines and cardiac magnetic resonance (CMR) abnormalities.

Methods

71 subjects (59% female, mean age 52±14) with previous diagnosis of COVID-19 infection were enrolled at our institution for MULTICOVID protocol, comprehensive of CMR and biomarkers assessment performed >3 months and <1 year following the first negative swab test. CMR protocols consisted of conventional sequences (cine, T2-weighted imaging, and late gadolinium enhancement [LGE]) and quantitative mapping sequences (T1, T2, and extracellular volume [ECV] mapping). Plasma levels of cytokines TNF-α, IL-1β, IL-1α, IFN-α2, IL-6, IL-8, IL-13, IL-10, IL-17A, IL-18, IP-10, MIG and MCP-1 were quantified by Multiplex Immunoassays on the Luminex technology platform. Soluble cardiologic and biochemical biomarkers were measured by routine laboratory analysis.

Results

After a median of 9 (IQR 6–11) months following negative swab, CMR was normal in 48 subjects, while in 23 (32%) it revealed tissue characterization abnormalities (myocardial late enhancement and/or edema). By multivariate regression analysis (adjusted for age, sex, vaccination, severity degrees of the initial COVID disease, presence of comorbidities, smoke, time interval between COVID diagnosis and CMR assessment) the cytokine ratio TNF-α/(IL-10+IL-13) was independently associated (OR=2.89, 95% CI 1.19–7.04, p=0.02) with CMR abnormalities. Interestingly, the cumulative pro-/anti-inflammatory cytokine ratio (IL-1β+TNF-α+IFN-α2+IL-6+IL-17A+IL-8)/(IL-10+IL-13) showed a positive (OR=1.70, 95% CI: 1.04–2.75) and significant (p=0.03) association with CMR imaging aspects. Also, the ratio IFN-α2/(IL-10+IL-13), although without achieving a complete statistical significance (p=0.09), was associated positively with CMR findings.

Conclusions

The preliminary results of this cross-sectional study suggest that the systemic inflammatory environment, long-lasting unbalanced towards a prevalent cytokine-driven pro-inflammatory condition following COVID infection, could affect the development of CMR-detectable myocardial edema and fibrosis in long-term post-COVID subjects.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Tuscany Region

CarDiac magnEtic Resonance for prophylactic Implantable-cardioVerter defibrillAtor ThErapy in Non-Ischaemic dilated CardioMyopathy: an international Registry

AIMS

The aim of this registry was to evaluate the additional prognostic value of a composite cardiac magnetic resonance (CMR)-based risk score over standard-of-care (SOC) evaluation in a large cohort of consecutive unselected non-ischaemic cardiomyopathy (NICM) patients.

METHODS AND RESULTS

In the DERIVATE registry (www.clinicaltrials.gov/registration: RCT#NCT03352648), 1000 (derivation cohort) and 508 (validation cohort) NICM patients with chronic heart failure (HF) and left ventricular ejection fraction <50% were included. All-cause mortality and major adverse arrhythmic cardiac events (MAACE) were the primary and secondary endpoints, respectively. During a median follow-up of 959 days, all-cause mortality and MAACE occurred in 72 (7%) and 93 (9%) patients, respectively. Age and >3 segments with midwall fibrosis on late gadolinium enhancement (LGE) were the only independent predictors of all-cause mortality (HR: 1.036, 95% CI: 1.0117-1.056, P < 0.001 and HR: 2.077, 95% CI: 1.211-3.562, P = 0.008, respectively). For MAACE, the independent predictors were male gender, left ventricular end-diastolic volume index by CMR (CMR-LVEDVi), and >3 segments with midwall fibrosis on LGE (HR: 2.131, 95% CI: 1.231-3.690, P = 0.007; HR: 3.161, 95% CI: 1.750-5.709, P < 0.001; and HR: 1.693, 95% CI: 1.084-2.644, P = 0.021, respectively). A composite clinical and CMR-based risk score provided a net reclassification improvement of 63.7% (P < 0.001) for MAACE occurrence when added to the model based on SOC evaluation. These findings were confirmed in the validation cohort.

CONCLUSION

In a large multicentre, multivendor cohort registry reflecting daily clinical practice in NICM work-up, a composite clinical and CMR-based risk score provides incremental prognostic value beyond SOC evaluation, which may have impact on the indication of implantable cardioverter-defibrillator implantation.

Clinical Risk Prediction in Patients With Left Ventricular Myocardial Noncompaction

BACKGROUND

Left ventricular noncompaction (LVNC) is a heterogeneous entity with uncertain prognosis.

OBJECTIVES

This study sought to develop and validate a prediction model of major adverse cardiovascular events (MACE) and to identify LVNC cases without events during long-term follow-up.

METHODS

This is a retrospective longitudinal multicenter cohort study of consecutive patients fulfilling LVNC criteria by echocardiography or cardiovascular magnetic resonance. MACE were defined as heart failure (HF), ventricular arrhythmias (VAs), systemic embolisms, or all-cause mortality.

RESULTS

A total of 585 patients were included (45 ± 20 years of age, 57% male). LV ejection fraction (LVEF) was 48% ± 17%, and 18% presented late gadolinium enhancement (LGE). After a median follow-up of 5.1 years, MACE occurred in 223 (38%) patients: HF in 110 (19%), VAs in 87 (15%), systemic embolisms in 18 (3%), and 34 (6%) died. LVEF was the main variable independently associated with MACE (P < 0.05). LGE was associated with HF and VAs in patients with LVEF >35% (P < 0.05). A prediction model of MACE was developed using Cox regression, composed by age, sex, electrocardiography, cardiovascular risk factors, LVEF, and family aggregation. C-index was 0.72 (95% confidence interval: 0.67-0.75) in the derivation cohort and 0.72 (95% confidence interval: 0.71-0.73) in an external validation cohort. Patients with no electrocardiogram abnormalities, LVEF ≥50%, no LGE, and negative family screening presented no MACE at follow-up.

CONCLUSIONS

LVNC is associated with an increased risk of heart failure and ventricular arrhythmias. LVEF is the variable most strongly associated with MACE; however, LGE confers additional risk in patients without severe systolic dysfunction. A risk prediction model is developed and validated to guide management.

Cardiac magnetic resonance findings in patients with type 1 myotonic dystrophy

Funding Acknowledgements

Type of funding sources: None.

Background

Heart disease is a major determinant of prognosis in type 1 myotonic dystrophy (DM1), second only to respiratory complications. Cardiac imaging, possibly including cardiac magnetic resonance (CMR), is recommended in patients with DM1. However, limited information is available on CMR findings and their prognostic significance in DM1.

Methods

We identified all patients with DM1 evaluated from 2009 to 2020 in a CMR laboratory with an established collaboration with a Neuromuscular Disorder Unit.

Results

Thirty-four patients were retrieved (21 males, aged 45 ± 12). At the time of CMR examination, 97% had neuromuscular symptoms (mean duration 16 ± 13 years), 12 (35%) presented with atrioventricular block (n = 11 1st degree, n = 1 2nd degree type 1), 15 (44%) with intraventricular conduction disturbances (n = 5 left bundle branch block, n = 5 right bundle branch block, n = 3 left anterior fascicular block, n = 2 other non-specific intraventricular conduction delay), 4 (12%) with atrial fibrillation or flutter. No patient had a device. At CMR, 5 (15%) patients had left ventricular (LV) systolic dysfunction (LV ejection fraction [LVEF] &lt;50%) and 5 (15%) a depressed right ventricular (RV) function (RVEF &lt;50%). Compared to age- and sex-specific reference values for our laboratory, 12 (35%) patients showed a decreased LV end-diastolic volume index (LVEDVi), 7 (21%) a decreased LV mass index (LVMi), and 29 (83%) a decreased LVMi/LVEDVi ratio. Nine (26%) patients had mid-wall late gadolinium enhancement (LGE, mean extent 4.5 ± 2.0% of LVM; n = 8 septal, n = 4 inferolateral, n = 2 inferior, n = 1 anterolateral), and 14 (40%) some areas of fatty infiltration (n = 9 involving the LV, n = 13 the RV). Native T1 in the interventricular septum (1,041 ± 53 ms) approached the upper reference limit (1,089 ms), and the extracellular volume was slightly increased (33 ± 2%, reference values &lt;30%). Over a median follow-up of 3.3 years (interquartile interval 1.6-4.7), 2 (6%) patients died, one for infectious and respiratory complications and the other for unknown causes, 5 (15%) patients underwent pacemaker implantation for conduction disturbances, and 4 (12%) had a documentation of high-risk (Lown class ≥4) ventricular ectopic beats (VEBs). Among all CMR variables collected, higher values of LVMi/LVEDVi ratio emerged as univariate predictor of all-cause death (p = 0.044). At logistic regression analysis, anteroseptal wall thickness was associated with the need for pacemaker implantation (p = 0.028), while LGE mass was associated with high-risk VEBs (p = 0.026).

Conclusions

Patients with DM1 display several structural and functional cardiac abnormalities, with variable degrees of cardiac muscle hypotrophy, fibrosis and fatty infiltration. The possibility to predict the need for pacemaker implantation, ventricular arrhythmias and all-cause or cardiovascular mortality should be verified in larger cohorts.

Late gadolinium enhancement predicts adverse clinical outcome in patients with mitral valve prolapse/mitral annulus disjunction

Funding Acknowledgements

Type of funding sources: None.

OnBehalf

Mitral vAlve prolapse and disjunction by cardiac maGnetIC resonance (MA-GIC) registry

Backgroung

Mitral valve prolapse (MVP) is 2-3% prevalent in the general population with good prognosis. However, some patients develop complex ventricular arrhythmias (CVAs), sudden cardiac death (SCD), or severe mitral regurgitation (MR). Previous studies suggested that bi-leaflet involvement, mitral annulus disjunction (MAD), and myocardial fibrosis (MF) are associated with adverse outcome. Notwithstanding, these findings were limited to autopsic series or single-centre studies involving highly selected patients. Moreover, MF has been scantly investigated as predictor of clinical outcome.

Purpose

To investigate the prognostic significance of MF in an international multicentre study of MVP patients studied by cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE). 

Methods

From October 2007 to June 2020 patients undergoing LGE-CMR were screened in 14 European centres. Inclusion criteria were: i) age &gt; 18 years; ii) full clinical history and cardiac rhythm monitoring at baseline; iii) MVP (leaflet displacement ≥ 2 mm beyond the annulus). Exclusion criteria were: i) ischemic heart disease; ii) primary cardiomyopathy; iii) inflammatory heart disease; iv) congenital heart diseases; v) moderate-to-severe valvular heart disease. CVAs at the study outset was defined as one of the following: i) ventricular ectopic beats &gt;10000/24h; ii) ≥ 1 episode of non-sustained ventricular tachycardia (VT); iii) sustained VT; iv) aborted SCD. Primary end-point was a composite of SCD, unexplained syncope, and mitral valve repair/replacement. Secondary end-point was a composite of SCD and unexplained syncope. 

Results

Four-hundred-fifty-eight MVP patients were eventually included (46 ± 16 years old, 51% males) of whom 68% had MAD. LGE was detected in 103 (22%) of subjects with mid-wall pattern (46%) in left ventricular (LV) lateral wall (66%) as the most prevalent feature. At baseline, 37% of LGE-positive patients vs. 18% of LGE-negative individuals had CVAs (P &lt; 0.001). SVT and/or aborted SCD were more prevalent in LGE-positive than in LGE-negative patients (9% vs 2%, P &lt; 0.001). By multivariable Cox-regression analysis, LGE presence or extent were strong independent predictors of the primary (HR = 4.02, P = 0.003 and HR = 4.76 per 10% increase, P = 0.032, respectively) and secondary (HR = 5.39, P = 0.008 and HR = 8.78 per 10% increase, P = 0.012, respectively) endpoints after correction for major confounders including LV volumes, left atrial size and MAD presence.

Conlusion

Myocardial fibrosis by LGE is the strongest independent predictor of clinical outcome in MVP. In contrast, MAD per se does not harbinger worse prognosis.

Evolution of acute myocarditis in a pediatric population: An MRI based study

BACKGROUND

Cardiac Magnetic Resonance (CMR) data regarding myocarditis presentation and disease course is still lacking in pediatric patients. We evaluate baseline CMR and evolution of functional and tissue abnormalities in children with acute myocarditis.

METHODS

CMR was performed in 125 patients with clinical diagnosis of acute myocarditis. Clinical follow-up was performed for a median of 498 (214-923) days.

RESULTS

LVEF was depressed (<55%) in 56 cases (45%) upon baseline CMR. LGE was found in 93 patients (77%) of cases. LGE was exclusively subepicardial in 29 patients (23%), while other LGE patterns (midwall/mixed) were present in 64 (51%). CMR was repeated in 92 (74%) patients. 67% presented recover of function at a median of 170 (70-746) days after onset of symptoms. Midwall/mixed LGE pattern had a statistically significant correlation with absent recover of function (OR 0.20 p 0.036). Thirteen patients (16%) had recovery from LV dysfunction but with persistence of LGE. Sub-epicardial pattern of LGE (OR 3.33, 95% CI 1.08-10.2, p = 0.036) and the presence of fever at admission (OR 4.67, 95% CI 1.16-18.7, p = 0.03) were associated with a significantly higher likelihood of complete normalization while midwall/mixed LGE pattern was associated with non-recovery.

CONCLUSIONS

In pediatric myocarditis, midwall/mixed LGE pattern is associated with absent recover of function. Patients with recover of function may still have persistence of LGE, while a complete recovery from functional and tissue abnormalities is found only in a third of patients. Midwall/mixed pattern of LGE at first MRI was associated to worse outcome.

Accuracy of right atrial pressure estimation using a multi-parameter approach derived from inferior vena cava semi-automated edge-tracking echocardiography: a pilot study in patients with cardiovascular disorders

The echocardiographic estimation of right atrial pressure (RAP) is based on the size and inspiratory collapse of the inferior vena cava (IVC). However, this method has proven to have limits of reliability. The aim of this study is to assess feasibility and accuracy of a new semi-automated approach to estimate RAP. Standard acquired echocardiographic images were processed with a semi-automated technique. Indexes related to the collapsibility of the vessel during inspiration (Caval Index, CI) and new indexes of pulsatility, obtained considering only the stimulation due to either respiration (Respiratory Caval Index, RCI) or heartbeats (Cardiac Caval Index, CCI) were derived. Binary Tree Models (BTM) were then developed to estimate either 3 or 5 RAP classes (BTM3 and BTM5) using indexes estimated by the semi-automated technique. These BTMs were compared with two standard estimation (SE) echocardiographic methods, indicated as A and B, distinguishing among 3 and 5 RAP classes, respectively. Direct RAP measurements obtained during a right heart catheterization (RHC) were used as reference. 62 consecutive 'all-comers' patients that had a RHC were enrolled; 13 patients were excluded for technical reasons. Therefore 49 patients were included in this study (mean age 62.2 ± 15.2 years, 75.5% pulmonary hypertension, 34.7% severe left ventricular dysfunction and 51% right ventricular dysfunction). The SE methods showed poor accuracy for RAP estimation (method A: misclassification error, ME = 51%, R² = 0.22; method B: ME = 69%, R² = 0.26). Instead, the new semi-automated methods BTM3 and BTM5 have higher accuracy (ME = 14%, R² = 0.47 and ME = 22%, R² = 0.61, respectively). In conclusion, a multi-parametric approach using IVC indexes extracted by the semi-automated approach is a promising tool for a more accurate estimation of RAP.

P995The extent of late gadolinium enhancement predicts defibrillator shocks in patients with non-ischaemic heart failure

Background

Implantable cardioverter defibrillator (ICD) is recommended for patients with non-ischaemic heart failure (HF) and left ventricular ejection fraction (LVEF) ≤35%, although most patients will not experience any appropriate ICD intervention. We assessed if cardiovascular magnetic resonance (CMR) findings may predict benefit from ICD implantation.

Methods and results

We retrieved the data of all patients (n=183) with non-ischaemic HF receiving an ICD for primary prevention at our Institution, and undergoing CMR within 1 month before implantation. 183 patients were evaluated (men 73%, median age 66 years, LVEF 24%, N-terminal fraction of pro-B-type natriuretic peptide 1217 ng/L, atrial fibrillation, flutter or atrial ectopic rhythm 21%). They received single-chamber (n=21, 12%), dual-chamber (n=34, 19%), or cardiac resynchronization therapy devices (n=127, 69%); 1 patient (1%) received a subcutaneous defibrillator. Twenty patients (11%) experienced a shock for ventricular tachycardia or fibrillation (VT/VF) over 2.5 years (0.8–5.4), and 13 (7%) had an inappropriate shock over 2.7 years (0.9–5.4). Late gadolinium enhancement (LGE) was present in 146 patients (80%), but on average accounted for limited percentage of LV mass (4% [2–11%]). LGE mass independently predicted shocks for VT/VF (HR 2.13, 95% CI 1.02–4.47; p=0.045). LGE mass ≥14% (the best cut-off at receiver operating characteristics analysis) independently predicted shocks for VT/VF (HR 3.82, 95% CI 1.51–9.68; p=0.005). LGE mass <4% was the only univariate predictor of inappropriate shocks (HR 4.82, 95% CI 1.07–21.76; p=0.041).

Conclusions

Patients with non-ischaemic HF and LGE mass ≥14% benefit most from ICD, while those with LGE mass <4% display mainly inappropriate shocks.

P597Clinical and prognostic correlates of volume/time curve at cardiac magnetic resonance in patients with non-ischemic heart failure and left bundle branch block

Background

In patients with non-ischaemic systolic heart failure (HF) and left bundle branch block (LBBB), the systolic phase of the left ventricular (LV) volume/time (V/t) curve at cardiac magnetic resonance (CMR) can display a wide or a narrow pattern (WP/NP). The clinical and prognostic significance of these patterns are currently unknown.

Methods

Consecutive patients with systolic non-ischaemic HF (LV ejection fraction <50%) and LBBB were enrolled. They underwent a baseline evaluation including CMR, and were periodically re-evaluated during follow-up. The endpoint was a composite of cardiovascular death, heart failure (HF)-related event, and ventricular arrhythmias requiring defibrillator shock.

Results

Out of 101 patients (mean age 64±11 years, males 50%), NP was found in 29 and WP in 72, with no difference in QRS duration. Patients with WP had worse clinical presentation and greater LV volumes, but similar LGE prevalence, extent or distribution. The WP subgroup displayed a greater maximal dyssynchrony time, expressed both as absolute duration (192±80 vs. 143±65 ms, P<0.001), and as percentage of the RR interval (25±11% vs. 8±4%, p<0.001). Even the systolic dyssynchrony index was higher in patients with WP (13±4 vs. 7±3%, p<0.001). The contractility index was lower in patients with the WP (2.6±1.2 vs 3.2±1.7, p<0.05). Over a median follow-up duration of 44 months (interquartile interval 23–59), only WP (p=0.029) and NT-proBNP (p=0.004) demonstrated an independent prognostic value for cardiac events.

Conclusions

In patients with non-ischaemic systolic HF and LBBB, the WP of V/t curves identifies a subgroup of patients with greater LV dyssynchrony, worse clinical conditions and prognosis.

P2728Prognostic impact of left atrial function in patients with cardiac amyloidosis: a cardiac magnetic resonance study

Background

Left atrial function (AEF) is a parameter of paramount importance that has a prognostic value in a number of heart conditions. Cardiac involvement in both light-chain and transthyretin amyloidosis is the main driver of prognosis and influences treatment strategies. Cardiac magnetic resonance (CMR) provides high quality images of the left and right atria using high temporal resolution steady state free precession (SSFP) cine sequences.

Purpose

The aim of our study was to assess by CMR left atrial function and his correlation with prognosis in patients with cardiac amyloidosis.

Method

We enrolled 80 consecutive patients with diagnosis of cardiac amyloidosis: 38 patients (47%) with light-chain and 42 patients (53%) with transthyretin one. CMR was performed using a 1.5-T scanner. In all subjects, the study of atria was obtained by acquiring cine steady-state free precession (SSFP). Left Atrial function was evaluated by the ratio between the maximum and the minimum LA volume. A median follow up of 937 days was performed and 36 patients (44%) died of cardiac causes. We evaluated cardiac death as endpoint. We split out all the patient in 4 different quartiles depending on left atrial function: in the first quartile patients with AEF≤14% that reflects severe atrial dysfunction, in the second quartile patients with AEF between 14 and 19%, in the third quartile patients with AEF between 19 and 36% and in the last one patients with AEF≥36% that represent patients with normal value of left atrial function.

Results

We found that CMR assessed left atrial function allowed to individuate and stratify the prognosis in patients with cardiac amyloidosis. The most effective parameter to evaluate cardiac death was left atrial function with a cut off ≤14% that could predict cardiac related mortality with the same accuracy in both light-chain and transthyretin amyloidosis patients. Kaplan Meier analysis showed that patients with AEF≤14% had a worse prognosis as compared to patient with AEF≥14% (log rank p. 0001). Furthermore patients with AEF≤14% have a cardiac death risk of 32% at 1 year and 61% at 3 years.

Kaplan Meier analysis

Conclusion

Cardiac magnetic resonance is an imaging modality that allows to individuate with great accuracy left atrial function in patients with various heart conditions and especially cardiac amyloidosis. CMR left atrial function assessment clearly identifies a subgroup of cardiac amyloid patients with an increased risk of death.

Measurement of myocardial amyloid deposition in systemic amyloidosis: insights from cardiovascular magnetic resonance imaging

BACKGROUND

Cardiac involvement in systemic amyloidosis is caused by the extracellular deposition of misfolded proteins, mainly immunoglobulin light chains (AL) or transthyretin (ATTR), and may be detected by cardiovascular magnetic resonance (CMR). The aim of this study was to measure myocardial extracellular volume (ECV) in amyloid patients with a novel T1 mapping CMR technique and to determine the correlation between ECV and disease severity.

METHODS

Thirty-six patients with biopsy-proven systemic amyloidosis (mean age 70 ± 9 years, 31 men, 30 with AL and six with ATTR amyloidosis) and seven patients with possible amyloidosis (mean age 64 ± 10 years, six men) underwent comprehensive clinical and CMR assessment, with ECV estimation from pre- and postcontrast T1 mapping. Thirty healthy subjects (mean age 39 ± 17 years, 21 men) served as the control group.

RESULTS

Amyloid patients presented with left ventricular (LV) concentric hypertrophy with impaired biventricular systolic function. Cardiac ECV was higher in amyloid patients (definite amyloidosis, 0.43 ± 0.12; possible amyloidosis, 0.34 ± 0.11) than in control subjects (0.26 ± 0.04, P < 0.05); even in amyloid patients without late gadolinium enhancement (0.35 ± 0.10), ECV was significantly higher than in the control group (P < 0.01). A cut-off value of myocardial ECV >0.316, corresponding to the 95th percentile in normal subjects, showed a sensitivity of 79% and specificity of 97% for discriminating amyloid patients from control subjects (area under the curve of 0.884). Myocardial ECV was significantly correlated with LV ejection fraction (R(2)  = 0.16), LV mean wall thickness (R(2)  = 0.41), LV diastolic function (R(2)  = 0.21), right ventricular ejection fraction (R(2)  = 0.13), N-terminal fragment of the pro-brain natriuretic peptides (R(2)  = 0.23) and cardiac troponin (R(2)  = 0.33).

CONCLUSION

Myocardial ECV was increased in amyloid patients and correlated with disease severity. Thus, measurement of myocardial ECV represents a potential noninvasive index of amyloid burden for use in early diagnosis and disease monitoring.

Magnetic resonance assessment of prevalence and correlates of right ventricular abnormalities in isolated left ventricular noncompaction

The aim of the present study was to evaluate the prevalence and correlates of right ventricular (RV) noncompaction (RVNC), RV systolic dysfunction, and RV myocardial fibrosis in patients with isolated left ventricular (LV) noncompaction (LVNC). For this purpose, cine and contrast-enhanced cardiac magnetic resonance imaging (MRI) was used. A total of 56 consecutive patients with isolated LVNC were included in the study. The diagnosis of isolated LVNC was based on the presence of standard cardiac MRI and clinical criteria. For each patient, cine and contrast-enhanced cardiac MR images were analyzed to evaluate the prevalence and correlates of RVNC, RV dysfunction, and late gadolinium enhancement (a surrogate of myocardial fibrosis) involving the RV. Mean age of the patient population was 45 ± 19 years; 35 patients (63%) were men. RVNC was observed in 5 patients (9%). Impaired RV systolic function was observed in 9 patients (16%). Late gadolinium enhancement was not observed in any RV segment. No association was found between wall motion abnormalities and noncompaction at RV segmental level (φ coefficient 0.041, p = 0.26). At multivariate analysis, LV ejection fraction was the only variable independently related to RV ejection fraction (β = 0.62, p <0.001). In conclusion, RV systolic dysfunction is present in a non-negligible proportion of patients with isolated LVNC; LV systolic function is the only variable independently related to RV systolic function.

A prospective randomized trial of thrombectomy versus no thrombectomy in patients with ST-segment elevation myocardial infarction and thrombus-rich lesions: MUSTELA (MUltidevice Thrombectomy in Acute ST-Segment ELevation Acute Myocardial Infarction) trial

OBJECTIVES

The aim of this study was to evaluate whether thrombectomy during primary percutaneous coronary intervention (pPCI) in patients with high thrombus burden improves myocardial reperfusion and reduces infarct size.

BACKGROUND

Thrombectomy aims at reducing distal thrombotic embolization during pPCI, improving myocardial reperfusion and clinical outcome.

METHODS

We randomized 208 patients with high thrombus burden in a 1:1 ratio to either pPCI with thrombectomy (Group T) or standard pPCI (Group S). Thrombectomy was performed with either rheolytic or manual aspiration catheters. Three-month magnetic resonance imaging was performed to assess infarct size and transmurality and microvascular obstruction (MVO). The primary endpoints were ST-segment elevation resolution (STR) >70% at 60 min and 3-month infarct size.

RESULTS

The baseline profile was similar between groups, except for a higher rate of initial Thrombolysis In Myocardial Infarction flow grade 3 in Group S (p = 0.002). Group T showed a significantly higher rate of STR (57.4% vs. 37.3%; p = 0.004) and of final myocardial blush 3 (68.3% vs. 52.9%; p = 0.03). Group T and Group S did not differ with regard to infarct size (20.4 ± 10.5% vs. 19.3 ± 10.6%; p = 0.54) and transmurality (11.9 ± 12.0% vs. 11.6 ± 12.7%; p = 0.92), but Group T showed significantly less MVO (11.4% vs. 26.7%; p = 0.02) and a higher prevalence of inhomogeneous scar (p < 0.0001). One-year freedom from major adverse cardiac events was similar between groups.

CONCLUSIONS

Thrombectomy as an adjunct to pPCI in patients with high thrombus load yielded better post-procedural STR and reduced MVO at 3 months but was not associated with a reduction in infarct size and transmurality. Thromboaspiration in Patients With High Thrombotic Burden Undergoing Primary Percutaneous (Coronary Intervention; NCT01472718).

Regional evidence of modulation of cardiac adiponectin level in dilated cardiomyopathy: pilot study in a porcine animal model

Background

The role of systemic and myocardial adiponectin (ADN) in dilated cardiomyopathy is still debated. We tested the regulation of both systemic and myocardial ADN and the relationship with AMP-activated protein kinase (AMPK) activity in a swine model of non-ischemic dilated cardiomyopathy.

Methods and results

Cardiac tissue was collected from seven instrumented adult male minipigs by pacing the left ventricular (LV) free wall (180 beats/min, 3 weeks), both from pacing (PS) and opposite sites (OS), and from five controls. Circulating ADN levels were inversely related to global and regional cardiac function. Myocardial ADN in PS was down-regulated compared to control (p < 0.05), yet ADN receptor 1 was significantly up-regulated (p < 0.05). No modifications of AMPK were observed in either region of the failing heart. Similarly, myocardial mRNA levels of PPARγ, PPARα, TNFα, iNOS were unchanged compared to controls.

Conclusions

Paradoxically, circulating ADN did not show any cardioprotective effect, confirming its role as negative prognostic biomarker of heart failure. Myocardial ADN was reduced in PS compared to control in an AMPK-independent fashion, suggesting the occurrence of novel mechanisms by which reduced cardiac ADN levels may regionally mediate the decline of cardiac function.

Pacing-induced regional differences in adenosine receptors mRNA expression in a swine model of dilated cardiomyopathy

The adenosinergic system is essential in the mediation of intrinsic protection and myocardial resistance to insult; it may be considered a cardioprotective molecule and adenosine receptors (ARs) represent potential therapeutic targets in the setting of heart failure (HF). The aim of the study was to test whether differences exist between mRNA expression of ARs in the anterior left ventricle (LV) wall (pacing site: PS) compared to the infero septal wall (opposite region: OS) in an experimental model of dilated cardiomyopathy. Cardiac tissue was collected from LV PS and OS of adult male minipigs with pacing-induced HF (n = 10) and from a control group (C, n = 4). ARs and TNF–α mRNA expression was measured by Real Time-PCR and the results were normalized with the three most stably expressed genes (GAPDH, HPRT1, TBP). Immunohistochemistry analysis was also performed. After 3 weeks of pacing higher levels of expression for each analyzed AR were observed in PS except for A₁R (A₁R: C = 0.6±0.2, PS = 0.1±0.04, OS = 0.04±0.01, p<0.0001 C vs. PS and OS respectively; A_2AR: C = 1.04±0.59, PS = 2.62±0.79, OS = 2.99±0.79; A_2BR: C = 1.2±0.1, PS = 5.59±2.3, OS = 1.59±0.46; A₃R: C = 0.76±0.18, PS = 8.40±3.38, OS = 4.40±0.83). Significant contractile impairment and myocardial hypoperfusion were observed at PS after three weeks of pacing as compared to OS. TNF-α mRNA expression resulted similar in PS (6.3±2.4) and in OS (5.9±2.7) although higher than in control group (3.4±1.5). ARs expression was mainly detected in cardiomyocytes. This study provided new information on ARs local changes in the setting of LV dysfunction and on the role of these receptors in relation to pacing-induced abnormalities of myocardial perfusion and contraction. These results suggest a possible therapeutic role of adenosine in patients with HF and dyssynchronous LV contraction.

Ferritin as a reporter gene for in vivo tracking of stem cells by 1.5-T cardiac MRI in a rat model of myocardial infarction

The methods currently utilized to track stem cells by cardiac MRI are affected by important limitations, and new solutions are needed. We tested human ferritin heavy chain (hFTH) as a reporter gene for in vivo tracking of stem cells by cardiac MRI. Swine cardiac stem/progenitor cells were transduced with a lentiviral vector to overexpress hFTH and cultured to obtain cardiospheres (Cs). Myocardial infarction was induced in rats, and, after 45 min, the animals were subjected to intramyocardial injection of ∼200 hFTH-Cs or nontransduced Cs or saline solution in the border zone. By employing clinical standard 1.5-Tesla MRI scanner and a multiecho T2* gradient echo sequence, we localized iron-accumulating tissue only in hearts treated with hFTH-Cs. This signal was detectable at 1 wk after infarction, and its size did not change significantly after 4 wk (6.33 ± 3.05 vs. 4.41 ± 4.38 mm2). Cs transduction did not affect their cardioreparative potential, as indicated by the significantly better preserved left ventricular global and regional function and the 36% reduction in infarct size in both groups that received Cs compared with control infarcts. Prussian blue staining confirmed the presence of differentiated, iron-accumulating cells containing mitochondria of porcine origin. Cs-derived cells displayed CD31, α-smooth muscle, and α-sarcomeric actin antigens, indicating that the differentiation into endothelial, smooth muscle and cardiac muscle lineage was not affected by ferritin overexpression. In conclusion, hFTH can be used as a MRI reporter gene to track dividing/differentiating stem cells in the beating heart, while simultaneously monitoring cardiac morpho-functional changes.

Endocardial and epicardial deformations in cardiac amyloidosis and hypertrophic cardiomyopathy

BACKGROUND

The aim of the present study was to analyze epicardial (EPI) and endocardial (ENDO) strain (S) in patients with transthyretin-related cardiac amyloidosis (TTR-CA) and hypertrophic cardiomyopathy (HCM) using echocardiography (TTE) with 2-dimensional feature tracking imaging (FTI).

METHODS AND RESULTS

Thirty-three subjects (11 with HCM, 11 with TTR-CA, and 11 healthy subjects as controls) with a New York Heart Association functional class ≤ II underwent conventional TTE and FTI. TTE was used for the evaluation of left ventricle (LV) wall thickness, mass, systolic and diastolic function. FTI was used for the evaluation of EPI and ENDO longitudinal, and circumferential, and radial S. LV wall thickness and mass were higher in both TTR-CA and HCM in comparison with controls (P < 0.001), but ejection fraction (EF) was similar among patients with TTR-CA, HCM and controls (63 ± 6%, 64 ± 6%, 61 ± 5%, respectively). ENDO and EPI longitudinal and circumferential S and radial S were significantly lower in HCM and TTR-CA when compared with controls (P < 0.01). No differences in EPI and ENDO longitudinal S, ENDO circumferential S and radial S were found between TTR-CA and HCM groups, while EPI circumferential S was significantly lower in the TTRCA group (6 ± 3.3%) than in the HCM group (8.1 ± 4.3%; P < 0.0001).

CONCLUSIONS

Longitudinal, circumferential and radial LV deformations are impaired in patients with TTR-CA and HCM with a preserved EF. Impairment of EPI circumferential strain is greater in TTR-CA than in HCM.

Myocardial fibrosis in isolated left ventricular non-compaction and its relation to disease severity

AIMS

The aim of the present study was to evaluate the prevalence and extent of myocardial fibrosis in patients with isolated left ventricular non-compaction (LVNC) and to determine its relation to clinical status and LV systolic function.

METHODS AND RESULTS

The cardiac magnetic resonance imaging (MRI) database of our institution was searched for all patients with a first diagnosis of isolated LVNC. The diagnosis of isolated LVNC was based on the presence of standard cardiac MRI and clinical criteria. For each patient, cine and contrast-enhanced cardiac MR images were analysed to evaluate LV systolic function and the prevalence and extent of late gadolinium enhancement (LGE), a surrogate of myocardial fibrosis. A total of 42 patients (mean age 46 ± 20 years, 62% male) were identified. Late gadolinium enhancement was observed in 23 (55%) patients with isolated LVNC, occupying 4.8 ± 6.7% of the LV mass. Both the presence and extent of LGE were significantly related to the number of abnormal clinical features (i.e. symptomatic status, resting electrocardiogram abnormalities, and 24 h Holter monitoring abnormalities; P < 0.001 and P= 0.001, respectively). Similarly, LGE was more prevalent and extensive in patients with LV ejection fraction (EF) < 50% compared with patients with LVEF ≥ 50% (90 vs. 23%; P< 0.001 and 8.9 ± 7.6 vs. 1.1 ± 2.4%; P< 0.001, respectively). At multivariate analysis, both the presence and extent of LV LGE were independently related to LVEF (β = -0.63; P < 0.001 and β = -0.62; P< 0.001, respectively).

CONCLUSION

Myocardial fibrosis is related to clinical disease severity and LV systolic dysfunction in isolated LVNC.

Intramural myocardial hemorrhagic rupture in a patient with metastatic cancer and myocardial infarction

A 77-year-old man with anterior ST-elevated myocardial infarction and lateral myocardial rupture underwent successful percutaneous revascularization. Cardiac magnetic resonance imaging (MRI) and positron emission tomography (PET) unveiled a disseminated metastatic cancer, likely responsible not only for a prothrombotic paraneoplastic syndrome but also for ventricular metastasis and myocardial rupture. The patient unfortunately died because of noncardiovascular complications of cancer.

Hyaluronan mixed esters of butyric and retinoic acid affording myocardial survival and repair without stem cell transplantation

Possible cardiac repair by adult stem cell transplantation is currently hampered by poor cell viability and delivery efficiency, uncertain differentiating fate in vivo, the needs of ex vivo cell expansion, and consequent delay in transplantation after the onset of heart attack. By the aid of magnetic resonance imaging, positron emission tomography, and immunohistochemistry, we show that injection of a hyaluronan mixed ester of butyric and retinoic acid (HBR) into infarcted rat hearts afforded substantial cardiovascular repair and recovery of myocardial performance. HBR restored cardiac [¹⁸F]fluorodeoxyglucose uptake and increased capillary density and led to the recruitment of endogenous Stro-1-positive stem cells. A terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling assay demonstrated that HBR-treated hearts exhibited a decrease in the number of apoptotic cardiomyocytes. In isolated rat cardiomyocytes and Stro-1 stem cells, HBR enhanced the transcription of vascular endothelial growth factor, hepatocyte growth factor, kdr, akt, and pim-1. HBR also increased the secretion of vascular endothelial growth factor and hepatocyte growth factor, suggesting that the mixed ester may have recruited both myocardial and Stro-1 cells also. An increase in capillarogenesis was induced in vitro with medium obtained from HBR-exposed cells. In the infarcted myocardium, HBR injection increased histone H4 acetylation significantly. Acetyl-H4 immunoreactivity increased in rat cardiomyocytes and Stro-1 cells exposed to HBR, compared with untreated cells. In conclusion, efficient cardiac regenerative therapy can be afforded by HBR without the need of stem cell transplantation or vector-mediated gene delivery.

Q-wave prediction of myocardial infarct location, size and transmural extent at magnetic resonance imaging

OBJECTIVE

We investigated how pathologic Q waves or equivalents predict location, size and transmural extent of myocardial infarction (MI).

METHODS

MI characteristics, detected by contrast-enhanced magnetic resonance imaging, were compared with 12-lead electrocardiogram in 79 patients with previous first MI.

RESULTS

Q waves involved only the anterior leads (V1-V4) in 13 patients: in all patients MI involved the anterior and anteroseptal walls and apex; 81% of scar tissue was within these regions. Q waves involved only the inferior leads (II, III, aVF) in 13 patients: in 12 of these patients MI involved the inferior and inferoseptal walls; however, only 59% of scar occupied these regions. Q waves involved only lateral leads (V5, V6, I, aVL) in 11 patients: in nine of these patients MI involved the lateral wall but only 27% of scar tissue was within this wall. Q waves involved two electrocardiogram locations in 42 patients. In the 79 patients as a whole, the number of anterior Q waves was related to anterior MI size (r=0.70); however, the number of inferior and lateral Q waves was only weakly related to MI size in corresponding territories (r=0.35 and 0.33). A tall and broad R wave in V1-V2 was a more powerful predictor of lateral MI size than Q waves. Finally, the number of Q waves accurately reflected the transmural extent of the infarction (r=0.70) only in anterior infarctions.

CONCLUSION

Q waves reliably predict MI location, size and transmural extent only in patients with anterior infarction. A tall and broad R wave in V1-V2 reflects a lateral MI.

The obesity paradox and myocardial infarct size

OBJECTIVE

Obese subjects have a risk of death from cardiovascular disease higher than those with normal body weight. Obese patients, however, have a better outcome when undergoing coronary revascularisation, and when suffering from heart failure or chronic kidney disease. The term 'obesity paradox' underlines the divergence between increased risk and better outcome in sick obese patients. We tested the hypothesis that the obesity paradox could also occur in myocardial infarction.

METHODS

A group of 89 patients (mean age 62 +/- 11 years) with previous myocardial infarction (Q-wave in 72 patients) underwent contrast-enhanced MRI.

RESULTS

Areas of delayed contrast enhancement (which reflects myocardial necrosis) were present in 15 +/- 9% of left ventricular myocardium. Infarct size was not influenced by patient age, gender, history of arterial hypertension, hypercholesterolaemia, hypertriglyceridaemia nor tobacco smoking. Infarct size, however, was larger in insulin-dependent diabetic patients (P = 0.06) and in those with a family history of premature coronary artery disease (P = 0.06). Surprisingly, infarct size was smaller in obese patients (11 +/- 4% of left ventricular myocardium) than in those with normal body weight (16 +/- 9% of left ventricular myocardium, P = 0.03). Insulin-dependent diabetes mellitus, obesity and family history of coronary artery disease were the only independent predictors of infarct size at multiple linear regression analysis.

CONCLUSIONS

Owing to its limitations (small sample size and exclusion of extremely obese patients), this study generates a working hypothesis, which should be tested in larger prospective studies, that the obesity paradox could also occur in myocardial infarction.

Mismatch between uniform increase in cardiac glucose uptake and regional contractile dysfunction in pacing-induced heart failure

Increased glucose utilization and regional differences in contractile function are well-known alterations of the failing heart and play an important pathophysiological role. We tested whether, similar to functional derangement, changes in glucose uptake develop following a regional pattern. Heart failure was induced in 13 chronically instrumented minipigs by pacing the left ventricular (LV) free wall at 180 beats/min for 3 wk. Regional changes in contractile function and stress were assessed by magnetic resonance imaging, whereas regional flow and glucose uptake were measured by positron emission tomography utilizing, respectively, the radiotracers [(13)N]ammonia and (18)F-deoxyglucose. In heart failure, LV end-diastolic pressure was 20 +/- 4 mmHg, and ejection fraction was 35 +/- 4% (all P < 0.05 vs. control). Sustained pacing-induced dyssynchronous LV activation caused a more pronounced decrease in LV systolic thickening (7.45 +/- 3.42 vs. 30.62 +/- 8.73%, P < 0.05) and circumferential shortening (-4.62 +/- 1.0 vs. -7.33 +/- 1.2%, P < 0.05) in the anterior/anterior-lateral region (pacing site) compared with the inferoseptal region (opposite site). Conversely, flow was reduced significantly by approximately 32% compared with control and was lower in the opposite site region. Despite these nonhomogeneous alterations, regional end-systolic wall stress was uniformly increased by 60% in the failing LV. Similar to wall stress, glucose uptake markedly increased vs. control (0.24 +/- 0.004 vs. 0.07 +/- 0.01 micromol x min(-1) x g(-1), P < 0.05), with no significant regional differences. In conclusion, high-frequency pacing of the LV free wall causes a dyssynchronous pattern of contraction that leads to progressive cardiac failure with a marked mismatch between increased glucose uptake and regional contractile dysfunction.