A Novel Approach to Cardiac Magnetic Resonance Scar Characterization in Patients Affected by Cardiac Amyloidosis: A Pilot Study.

Background and Objectives: Cardiac magnetic resonance (CMR) imaging has become an essential instrument in the study of cardiomyopathies; it has recently been integrated into the diagnostic workflow for cardiac amyloidosis (CA) with remarkable results. An additional emerging role is the stratification of the arrhythmogenic risk by scar analysis and the possibility of merging these data with electro-anatomical maps. This is made possible by using a software (ADAS 3D, Galgo Medical, Barcelona, Spain) able to provide 3D heart models by detecting fibrosis along the whole thickness of the myocardial walls. Little is known regarding the applications of this software in the wide spectrum of cardiomyopathies and the potential benefits have yet to be discovered. In this study, we tried to apply the ADAS 3D in the context of CA. Materials and Methods: This study was a retrospectively analysis of consecutive CMR imaging of patients affected by CA that were treated in our center (Marche University Hospital). Wherever possible, the data were processed with the ADAS 3D software and analyzed for a correlation between the morphometric parameters and follow-up events. The outcome was a composite of all-cause mortality, unplanned cardiovascular hospitalizations, sustained ventricular arrhythmias (VAs), permanent reduction in left ventricular ejection fraction, and pacemaker implantation. The secondary outcomes were the need for a pacemaker implantation and sustained VAs. Results: A total of 14 patients were deemed eligible for the software analysis: 8 patients with wild type transthyretin CA, 5 with light chain CA, and 1 with transthyretin hereditary CA. The vast majority of imaging features was not related to the composite outcome, but atrial wall thickening displayed a significant association with both the primary (p = 0.003) and the secondary outcome of pacemaker implantation (p = 0.003). The software was able to differentiate between core zones and border zones of scars, with the latter being the most extensively represented in all patients. Interestingly, in a huge percentage of CMR images, the software identified the highest degree of core zone fibrosis among the epicardial layers and, in those patients, we found a higher incidence of the primary outcome, without reaching statistical significance (p = 0.18). Channels were found in the scar zones in a substantial percentage of patients without a clear correlation with follow-up events. Conclusions: CMR imaging plays a pivotal role in cardiovascular diagnostics. Our analysis shows the feasibility and applicability of such instrument for all types of CA. We could not only differentiate between different layers of scars, but we were also able to identify the presence of fibrosis channels among the different scar zones. None of the data derived from the ADAS 3D software seemed to be related to cardiac events in the follow-up, but this might be imputable to the restricted number of patients enrolled in the study.

Characteristics and Clinical Value of Electroanatomic Voltage Mapping in Cardiac Amyloidosis.

BACKGROUND: Cardiac amyloidoses (CAs) are an increasingly recognised group of infiltrative cardiomyopathies associated with high risk of adverse cardiac events. We sought to characterise the characteristics and clinical value of right ventricular (RV) electroanatomic voltage mapping (EVM) in CA. METHODS: Fifteen consecutive patients undergoing endomyocardial biopsy (EMB) for suspected CA (median age 75 years, 1st-3rd quartiles 64-78 years], 67% male) were enrolled in an observational prospective study. Each patient underwent RV high-density EVM using a multipolar catheter and EMB. The primary outcome was death or heart failure hospitalisation at 1-year follow-up. We recorded electrographic features at EMB sampling sites and electroanatomic data in the overall RV, and explored their correlations with histopathologic findings and primary outcomes events. RESULTS: A final EMB-proven diagnosis of immunoglobulin light chain or transthyretin CA was formulated in 6 and 9 patients, respectively. Electrogram amplitudes in the bipolar and unipolar configurations averaged 1.55 ± 0.44 mV and 5.14 ± 1.50 mV, respectively, in the overall RV, with lower values in AL CA patients. We found a significant inverse correlation between both bipolar and unipolar electrogram amplitude and amyloid burden according to EMB (P = 0.001 and P = 0.025, respectively). At 1-year follow-up, 7 patients (47%) experienced a primary outcome event; the extent of bipolar dense scar area at RV EVM was an independent predictor of primary outcome events at multivariable analysis (odds ratio 2.40; P = 0.037). CONCLUSIONS: In CA, electrogram amplitudes are around the lower limit of normal yet disproportionately low compared with the increased wall thickness. Out data suggest that RV electrogram amplitude may be a quantitative marker of amyloid burden, and that RV EVM may have prognostic value.

Real-world candidacy to mavacamten in a contemporary hypertrophic obstructive cardiomyopathy population.

AIMS: In the EXPLORER-HCM trial, mavacamten reduced left ventricular outflow tract obstruction (LVOTO) and improved functional capacity of symptomatic hypertrophic obstructive cardiomyopathy (HOCM) patients. We sought to define the potential use of mavacamten by comparing real-world HOCM patients with those enrolled in EXPLORER-HCM and assessing their eligibility to treatment. METHODS AND RESULTS: We collected information on HOCM patients followed up at 25 Italian HCM outpatient clinics and with significant LVOTO (i.e. gradient ≥30 mmHg at rest or ≥50 mmHg after Valsalva manoeuvre or exercise) despite pharmacological or non-pharmacological therapy. Pharmacological or non-pharmacological therapy resolved LVOTO in 1044 (61.2%) of the 1706 HOCM patients under active follow-up, whereas 662 patients (38.8%) had persistent LVOTO. Compared to the EXPLORER-HCM trial population, these real-world HOCM patients were older (62.1 ± 14.3 vs. 58.5 ± 12.2 years, p = 0.02), had a lower body mass index (26.8 ± 5.3 vs. 29.7 ± 4.9 kg/m2 , p < 0.0001) and a more frequent history of atrial fibrillation (21.5% vs. 9.8%, p = 0.027). At echocardiography, they had lower left ventricular ejection fraction (LVEF, 66 ± 7% vs. 74 ± 6%, p < 0.0001), higher left ventricular outflow tract gradients at rest (60 ± 27 vs. 52 ± 29 mmHg, p = 0.003), and larger left atrial volume index (49 ± 16 vs. 40 ± 12 ml/m2 , p < 0.0001). Overall, 324 (48.9%) would have been eligible for enrolment in the EXPLORER-HCM trial and 339 (51.2%) for treatment with mavacamten according to European guidelines. CONCLUSIONS: Real-world HOCM patients differ from the EXPLORER-HCM population for their older age, lower LVEF and larger atrial volume, potentially reflecting a more advanced stage of the disease. About half of real-world HOCM patients were found eligible to mavacamten.

Exercise-induced ventricular arrhythmias and risk of sudden cardiac death in patients with hypertrophic cardiomyopathy.

BACKGROUND: Non-sustained ventricular tachycardia (NSVT) during ambulatory electrocardiographic monitoring (typically occurring at rest or during sleep) is associated with an increased risk of sudden cardiac death in patients with hypertrophic cardiomyopathy. The prevalence and prognostic significance of ventricular arrhythmias during exercise is unknown. METHODS AND RESULTS: This was a cohort study, with prospective data collection. We studied 1380 patients, referred to a cardiomyopathy clinic in London, UK [mean age 42 years (SD 15); 62% male; mean follow-up 54 (SD 49) months]. Patients underwent two-dimensional and Doppler echocardiography, upright exercise testing, and Holter monitoring. Twenty-seven patients [mean age 40 (SD 14) years (18-64); 22 (81.5%) male] had NSVT (24) or ventricular fibrillation (VF) (3) during exercise. During exercise, 13 (54.2%) had more than one run of NSVT (maximum 5) with a mean heart rate of 221 (SD 48) b.p.m. Patients with exercise NSVT/VF had more severe hypertrophy (22.6 vs. 19.5 mm, P = 0.009) and larger left atria (47.3 vs. 43.7 mm, P = 0.03). Male gender was significantly associated with exercise NSVT/VF [22 (81.5%) vs. 832 (61.5%), P = 0.03]. Eight (29.6%) of the exercise NSVT/VF patients died or had a cardiac event (SD/ICD discharge/transplant) compared with 150 (11.1%) patients without exercise NSVT/VF, P = 0.008. Patients with NSVT/VF had a 3.73-fold increase in risk of SD/ICD discharge (HR 95% CI: 1.61-8.63, P = 0.002). Exercise NSVT alone was associated with a 2.82-fold increased risk (HR 95% CI: 1.02-7.75, P = 0.049). In multivariable analysis with other risk markers, exercise NSVT/VF (but not NSVT alone) was independently associated with an increased risk of SD/ICD [HR 3.14 (95% CI: 1.29-7.61, P = 0.01)]. CONCLUSION: Ventricular arrhythmia during symptom limited exercise is rare in patients with hypertrophic cardiomyopathy, but is associated with an increased risk of sudden cardiac death.

Heart transplantation in hypertrophic cardiomyopathy.

Heart transplantation (HT) is the sole therapeutic option for selected patients with hypertrophic cardiomyopathy (HC) and refractory heart failure. However, the results of HT have not been systematically investigated in HC. We assessed the pathophysiologic profile of HT candidates and the outcome after transplantation in 307 patients with HC consecutively evaluated at our tertiary referral center from 1987 to 2005; follow-up was 9.9+8.2 years. Outcome of recipients with HC was compared with that of 141 patients who underwent transplantation for idiopathic dilated cardiomyopathy at our center over the same period. Of 21 patients with HC who entered the transplantation list, 20 had end-stage evolution with systolic dysfunction and 1 had an extremely small left ventricular cavity with impaired filling and recurrent cardiogenic shock during paroxysmal atrial fibrillation. Of 33 study patients with HC who showed end-stage evolution during follow-up, the 23 who were included on the waiting list or died from refractory heart failure (2 patients) were significantly younger than the 10 patients who remained clinically stable (37+/-14 vs 57+/-17 years, p=0.004). Of the 21 HT candidates, 18 underwent transplantation during follow-up. In heart transplant recipients, 7-year survival rate was 94% and not different from that of the 141 patients who received transplants for idiopathic dilated cardiomyopathy (p=0.66). In conclusion, long-term outcome after HT in patients with HC is favorable and similar to that of patients with idiopathic dilated cardiomyopathy. In patients with end-stage HC, young age is associated with more rapid progression to refractory heart failure.

Frequency, determinants, and clinical relevance of acute coronary syndrome-like electrocardiographic findings in patients with acute aortic syndrome.

We investigated frequency/characteristics of acute coronary syndrome-like (ACS-like) electrocardiographic (ECG) profiles among patients with a final diagnosis of acute aortic syndrome (AAS), and explored pathophysiologic determinants and prognostic relevance within each Stanford subtype. We blindly reviewed presentation electrocardiograms of 233 consecutive patients with final diagnosis of AAS (164 Stanford type A) at a regional treatment center. Prevalence of ACS-like ECG findings was 27% (type A, 26%, type B, 29%); most were non-ST-elevation myocardial infarction-like. Patients with ACS-like ECG findings more often had coronary ostia involvement (p=0.002), pleural effusion (p=0.02), significant aortic regurgitation (p=0.01), and troponin positivity (p=0.001). ACS-like ECG profile in type A disease was independently associated with coronary ostia involvement (odds ratio [OR] 5.27, 95% confidence interval [CI] 1.75 to 15.88). ACS-like ECG profile predicted in-hospital mortality (OR 2.90, 95% CI 1.24 to 6.12), as did age (each incremental 10-year: OR 1.59, 95% CI 1.14 to 2.22), and syncope at presentation (OR 2.90, 95% CI 1.16 to 7.24). In conclusion, about 25% of our AAS patients (in either Stanford subtype) presented ACS-like ECG patterns-often with non-ST-elevation myocardial infarction characteristics-which could cause misdiagnosis. ACS-like ECG profile was associated with more complicated disease, and in type A disease was a strong independent predictor of in-hospital mortality.

Different types of cardiomyopathy associated with isolated ventricular noncompaction.

Although mainly described in the context of dilated and hypokinetic left ventricles, it is unclear whether isolated ventricular noncompaction (IVNC) is a distinct cardiomyopathy, a subtype of dilated cardiomyopathy, or a morphogenetic disorder. To investigate the spectrum of cardiomyopathies associated with IVNC, children and adults with stringent echocardiographic diagnoses of IVNC were reviewed. Seventy-three patients (12 children aged <15 years) seen since 1994 satisfied stringent echocardiographic criteria for IVNC. Sixty-five patients (89%; 11 children) had dilated cardiomyopathy, 2 adults had clear-cut hypertrophic cardiomyopathy, 1 adult had restrictive cardiomyopathy (to the investigators' knowledge, the first reported example of this particular association), and 5 patients (1 child) had normal left ventricular morphology and function. In conclusion, knowledge that IVNC can co-exist with restrictive and hypertrophic cardiomyopathy (in addition to the dilated form) supports the concept that IVNC is a morphologic trait rather than a distinct cardiomyopathy. This knowledge should be taken into account during echocardiographic examination and encourage the use of contrast echocardiography (and magnetic resonance) and could also orient molecular biology studies.

Paradoxical contributions of non-compacted and compacted segments to global left ventricular dysfunction in isolated left ventricular noncompaction.

The pathophysiologic mechanisms of left ventricular (LV) dysfunction in isolated ventricular noncompaction (IVNC) remain unclear. Evaluating global and segmental systolic LV function in 65 patients with IVNC, this study found that normal wall motion was more common in noncompacted than in compacted segments. The number of noncompacted segments per patient correlated positively with the LV ejection fraction and negatively with LV end-diastolic volume index. These paradoxical findings support the concept that noncompaction represents a marker of a more generalized (cardio)myopathy rather than the direct pathophysiologic substrate of this still little-understood disease.

Ventricular remodeling in Loeffler endocarditis: implications for therapeutic decision making.

BACKGROUND: Little is known about the morphological and functional evolution of ventricular abnormalities in Loeffler endocarditis. METHODS AND RESULTS: We describe 5 patients, including 3 with long-term echocardiographic follow-up, in whom apical obliteration due to fibro-thrombotic thickening of the endocardium showed favorable patterns of evolution. In one patient there was almost complete resolution of the obliterative process with consequently increased effective ventricular volume. In two patients formation of a flow-passage in the fibrocalcific apical 'floor' between the main medioventricular cavity and the apical chamber, leading to a 'double-chambered' left ventricle was observed. CONCLUSIONS: Medical therapy and appropriate anticoagulation, can induce favorable long-term ventricular remodeling in Loeffler endocarditis.

Implications of cardiac resynchronization therapy and prophylactic defibrillator implantation among patients eligible for heart transplantation.

This study analyzed the relations and time-related changes in eligibility for cardiac resynchronization therapy and prophylactic defibrillator implantation in 161 potential candidates for heart transplantation. Although up to 62% of patients who fulfilled the severity criteria for heart transplantation were eligible for either device, this percentage increased as clinical/instrumental parameters of heart failure severity worsened.

Dilated-hypokinetic evolution of hypertrophic cardiomyopathy: prevalence, incidence, risk factors, and prognostic implications in pediatric and adult patients.

OBJECTIVES: This study sought to investigate the incidence, risk factors, and prognosis of dilated-hypokinetic evolution in a large cohort of patients with hypertrophic cardiomyopathy (HCM) followed up at a cardiology center serving both the pediatric and the adult population. BACKGROUND: The available data on this evolution of HCM mainly regards prevalence (rather than incidence) in adults, with very little being known about the pediatric population. METHODS: A total of 222 consecutive HCM patients (65% men, 19% < or =18 years old) were prospectively evaluated for a mean follow-up of 11 +/- 9 years. RESULTS: A diagnosis of dilated-hypokinetic HCM was made in 12 patients at first evaluation (11 without previous septal myectomy surgery; prevalence, 4.9%). Twelve of the 210 patients with classic HCM at first evaluation underwent dilated-hypokinetic evolution (incidence, 5.3/1,000 patient-years). Patients with prevalent/incident dilated-hypokinetic evolution were younger at first evaluation (32 +/- 14 years vs. 41 +/- 21 years, p = 0.04) and more often had a family history of HCM (61% vs. 26%, p = 0.002) or sudden death (43% vs. 19%, p = 0.01) with respect to patients who maintained classic HCM. Moreover, they showed greater interventricular septum (23 +/- 3 mm vs. 19 +/- 6 mm, p = 0.004) and posterior wall (15 +/- 3 mm vs. 13 +/- 4 mm, p = 0.006) thickness. Cardiovascular death-free survival was lower among patients with dilated-hypokinetic HCM (p < 0.04). Cox proportional hazards regression analysis identified left ventricular wall thickness (hazard ratio [HR] = 1.07; 95% confidence interval [CI], 1.01 to 1.14; p = 0.03) and end-diastolic diameter (HR = 1.08; 95% CI 1.04 to 1.11; p = 0.0001) as independent predictors of cardiovascular death. CONCLUSIONS: Dilated-hypokinetic evolution is rare but not exceptional in HCM. Young age at diagnosis, family history of HCM, and greater wall thickness are incremental risk factors for dilated-hypokinetic HCM, which carries an ominous prognosis.

Transesophageal echocardiography-guided algorithm for stent-graft implantation in aortic dissection.

OBJECTIVE: Endovascular stent-graft placement is replacing traditional surgery in type B aortic dissection. Usually stent-graft implantation is performed under fluoroscopic and angiographic guidance, but this relatively new procedure is still burdened with some complications. We investigated the value of a developed algorithm based on transesophageal echocardiography (TEE) for guiding stent-graft implantation in type B aortic dissection. METHODS: Forty-two patients with type B aortic dissection (chronic in 28 patients with aneurysmal dilatation of the false lumen, and acute complicated in 14 patients) underwent endovascular stent-graft reconstruction of the descending thoracic aorta. TEE was always performed after angiography. TEE-induced variations of the procedure, based on the algorithm, were compared with initial angiography-based decisions. RESULTS: TEE was decisive for guidewire repositioning (not possible with fluoroscopy) from the false to the true lumen in 3 patients and for correct guidewire entrance in an elephant trunk prosthesis in another patient. After stent-graft implantation color Doppler TEE enabled detection of proximal peri-stent leaks in 13 patients, whereas only 6 (46%) of the 13 leaks were detectable at angiography (P = .008). Most leaks were subsequently eliminated with balloon dilation or further stent grafting. Pulsed Doppler TEE was also useful for differentiating true leaks (13 patients) from Dacron porosity (7 patients). A pulsed-Doppler velocity cutoff value of 50 cm/s enabled differentiation of Dacron porosity (characterized by slow blood flow) from true peri-stent leak (fast flow). After stent-graft implantation TEE demonstrated new intimal tears in the thoracic aorta in 7 patients, whereas only 2 of the 7 new tears were detectable at angiography (P = .024); in 6 of 7 patients the new distal tears were subsequently resolved with placement of additional stents, whereas in a patient with Marfan syndrome new proximal tears determined a type I endoleak, which could not be resolved. Overall, TEE furnished decisive information additional to angiography in determining successful procedural changes in 16 of 42 patients (38%). There were no in-hospital deaths, and pre-discharge spiral computed tomograms showed a good outcome of stent-graft implantation in 37 of 42 patients (88%), with 5 residual type I endoleaks, all previously detected with TEE but impossible to eliminate with either balloon molding or further stent implantation. All but 2 patients (95%) are currently alive at mean follow-up of 30 +/- 18 months. CONCLUSIONS: TEE algorithm is an easy and useful tool in the operating room to guide correct stent-graft positioning in type B aortic dissection.