Implementation of an epicardial implantable MEMS sensor for continuous and real-time postoperative assessment of left ventricular activity in adult minipigs over a short- and long-term period

The sensing of left ventricular (LV) activity is fundamental in the diagnosis and monitoring of cardiovascular health in high-risk patients after cardiac surgery to achieve better short- and long-term outcome. Conventional approaches rely on noninvasive measurements even if, in the latest years, invasive microelectromechanical systems (MEMS) sensors have emerged as a valuable approach for precise and continuous monitoring of cardiac activity. The main challenges in designing cardiac MEMS sensors are represented by miniaturization, biocompatibility, and long-term stability. Here, we present a MEMS piezoresistive cardiac sensor capable of continuous monitoring of LV activity over time following epicardial implantation with a pericardial patch graft in adult minipigs. In acute and chronic scenarios, the sensor was able to compute heart rate with a root mean square error lower than 2 BPM. Early after up to 1 month of implantation, the device was able to record the heart activity during the most important phases of the cardiac cycle (systole and diastole peaks). The sensor signal waveform, in addition, closely reflected the typical waveforms of pressure signal obtained via intraventricular catheters, offering a safer alternative to heart catheterization. Furthermore, histological analysis of the LV implantation site following sensor retrieval revealed no evidence of myocardial fibrosis. Our results suggest that the epicardial LV implantation of an MEMS sensor is a suitable and reliable approach for direct continuous monitoring of cardiac activity. This work envisions the use of this sensor as a cardiac sensing device in closed-loop applications for patients undergoing heart surgery.

Prognostic Role of the Progression of Late Gadolinium Enhancement in Hypertrophic Cardiomyopathy

In hypertrophic cardiomyopathy (HCM), late gadolinium enhancement (LGE) extent ≥15% of left ventricular mass is considered a prognostic risk factor. LGE extent increases over time and the clinical role of the progression of LGE over time (LGE rate) was not prospectively evaluated. We sought to evaluate the prognostic role of the LGE rate in HCM. We enrolled 105 patients with HCM who underwent cardiac magnetic resonance (CMR) at baseline (CMR-I) and after ≥2 years of follow-up (CMR-II). LGE rate was defined as the ratio between the increase of LGE extent (grams) and the time interval (months) between examinations. A combined end point of sudden cardiac death, resuscitated cardiac arrest, appropriate Implanted Cardioverter Defibrillator (ICD) intervention, and sustained ventricular tachycardia was used (hard events). The percentage of patients with LGE extent ≥15% increased from 9% to 20% from CMR-I to CMR-II (p = 0.03). During a median follow-up of 52 months, 25 hard events were recorded. The presence of LGE ≥15% at CMR-II allowed a significant reclassification of the risk of patients than at LGE ≥15% at CMR-I (net reclassification improvement 0.21, p = 0.046). On the MaxStat analysis, the optimal prognostic cut point for LGE rate was >0.07 g/month. On the Kaplan-Meier curve, patients with LGE rate >0.07 had worse prognosis than those without (p <0.0001). LGE rate >0.07 allowed a significant reclassification of the risk compared with LGE ≥15% at CMR-I and at CMR-II (net reclassification improvement 0.49, p = 0.003). In the multivariable models, LGE rate >0.07 was the best independent predictor of hard events. In conclusion, CMR should be repeated after 2 years to reclassify the risk for sudden death of those patients. A high LGE rate may be considered a novel prognostic factor in HCM.

Diagnostic Role of Native T1 Mapping Compared to Conventional Magnetic Resonance Techniques in Cardiac Disease in a Real-Life Cohort

We sought to compare native T1 mapping to conventional late gadolinium enhancement (LGE) and T2-STIR techniques in a cohort of consecutive patients undergoing cardiac MRI (CMR). CMR was performed in 323 patients, 206 males (64%), mean age 54 ± 8 years, and in 27 age- and sex- matched healthy controls. In T2-STIR images, myocardial hyperintensity suggesting edema was found in 41 patients (27%). LGE images were positive in 206 patients (64%). T1 mapping was abnormal in 171 (49%). In 206 patients (64%), a matching between LGE and native T1 was found. T1 was abnormal in 32 out of 41 (78%) with edema in T2-STIR images. Overall, LGE and/or T2-STIR were abnormal in 209 patients, whereas native T1 was abnormal in 154 (52%). Conventional techniques and T1 mapping were concordant in 208 patients (64%). In 39 patients, T1 mapping was positive despite negative conventional techniques (12%). T1 mapping was able in conditions with diffuse myocardial damage such as cardiac amyloidosis, scleroderma, and Fabry disease (additive role in 42%). In contrast, T1 mapping was less effective in cardiac disease with regional distribution of myocardial damage such as myocardial infarction, HCM, and myocarditis. In conclusion, conventional LGE/T2-STIR and T1 mapping are complementary techniques and should be used together in every CMR examination.

Dark papillary muscles sign: a novel prognostic marker for cardiac magnetic resonance

OBJECTIVES

The prognostic role of left ventricular (LV) papillary muscle abnormalities in patients with preserved LV systolic ejection fraction (LVEF) is unknown. We sought to evaluate the prognosis role of LV papillary muscle abnormalities by CMR in patients with ventricular arrhythmias, preserved LVEF with no cardiac disease.

METHODS

A total of 391 patients with > 500/24 h premature ventricular complexes and/or with non-sustained ventricular tachycardia (NSVT), preserved LVEF, and no cardiac disease were enrolled. Different features of LV papillary muscles were considered: supernumerary muscles, papillary thickness, the attachment, late gadolinium enhancement (LGE). Dark-Paps was defined as end-systolic signal hypointensity of both papillary muscles in early post-contrast cine CMR images. Mitral valve prolapse, mitral annular disjunction (MAD), and myocardial LGE were considered.

RESULTS

Dark-Paps was found in 79 (20%) patients and was more frequent in females. It was associated with higher prevalence of mitral valve prolapse and MAD. During a median follow-up of 2534 days, 22 hard cardiac events occurred. At Kaplan-Meier curve analysis, patients with Dark-Paps were at higher risk of events than those without (p < 0.0001). Dark-Paps was significantly associated with hard cardiac events in all the multivariate models. Dark-Paps improved prognostic estimation when added to NSVT (p = 0.0006), to LGE (p = 0.005) and to a model including NSVT+LGE (p = 0.014). Dark-Paps allowed a significant net reclassification when added to NSVT (NRI 0.30, p = 0.03), to LGE (NRI 0.25, p = 0.04), and to NSVT + LGE (NRI 0.32, p  = 0.02).

CONCLUSIONS

In LV papillary muscles, Dark-Paps is a novel prognostic marker in patients with ventricular arrhythmias and preserved ejection fraction.

KEY POINTS

• Papillary muscle abnormalities are seen in patients with ventricular arrhythmias and preserved left ventricular ejection fraction. • Early post-contrast hypointensity of papillary muscles in end-systolic cine images (Dark-Paps) is a novel prognostic marker in patients with ventricular arrhythmias and preserved ejection fraction. • Dark-Paps had an additive prognostic role over late gadolinium enhancement and non-sustained ventricular tachycardia.

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 &gt;3 months and &lt;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

Incidence of acute myocarditis and pericarditis during the coronavirus disease 2019 pandemic: comparison with the prepandemic period

BACKGROUND

Myocarditis and pericarditis have been proposed to account for a proportion of cardiac injury during SARS-CoV-2 infection. The impact of COVID-19 the pandemic on the incidence of this acute inflammatory cardiac disease was not systematically evaluated.

AIM

To examine the incidence and prevalence of inflammatory heart disorders prior to and during the COVID-19 pandemic.

METHODS

We compared the incidence and prevalence of acute inflammatory heart diseases (myocarditis, pericarditis) in the provinces of Pisa, Lucca and Livorno in two time intervals: prior to (PRECOVID, from 1 June 2018 to 31 May 2019) and during the COVID-19 pandemic (COVID, from 1 June 2020 to May 2021).

RESULTS

Overall 259 cases of inflammatory heart disease (myocarditis and/or pericarditis) occurred in the areas of interest. The annual incidence was of 11.3 cases per 100 000 inhabitants. Particularly, 138 cases occurred in the pre-COVID, and 121 in the COVID period. The annual incidence of inflammatory heart disease was not significantly different (12.1/100 000 in PRECOVID vs 10.3/100 000 in COVID, P = 0.22). The annual incidence of myocarditis was significantly higher in PRECOVID than in COVID, respectively 8.1/100 000/year vs. 5.9/100 000/year (P = 0.047) consisting of a net reduction of 27% of cases. Particularly the incidence of myocarditis was significantly lower in COVID than in PRECOVID in the class of age 18-24

C63 PHENOTYPE – GENOTYPE RELATIONSHIP IN ARRHYTHMOGENIC CARDIOMYOPATHY

Background

Arrhythmogenic cardiomyopathy (ACM) is a primary disease of the myocardium with arrhythmic manifestations and fibro–fatty replacement either of the right (RV) or the left ventricle (LV) at the cardiac magnetic resonance (CMR). Over the last decade, different mutations in cardiac genes associated with heterogeneous phenotypes have been identified.

Aim

To investigate the genotype–phenotype relationships in ACM patients. Firstly, the phenotypic expression was defined in definite mutation carriers. Secondly, the prognostic significance of mutations was assessed across different phenotypes.

Methods

The study population included 281 patients with suspected ACM, based on family history, clinical and electrocardiographic evaluation, echocardiographic and CMR findings (Fig.1), studied at our Institution since 2012. All patients underwent genetic evaluation using Sanger sequencing and NGS of mutations in desmosomal (desmoplakin [DSP], plakophilin–2[PKP2], plakoglobin[JUP], desmoglein–2 [DSG2], desmocollin–2 [DSC2]) or non desmosomal genes. The composite endpoint included cardiac death, sustained and non–sustained ventricular tachycardia (VT), ventricular fibrillation (VF), appropriate defibrillator shock/antitachycardia pacing (ATP).

Results

The genetic test was positive in 113 patients (40%), 82 (73%) for desmosomal genes (41 DSP, 15 DSG2, 15 PKP2, 5 JUP, 6 DSC2), and 31 (27%) for non–desmosomal genes (4 titin, 2 TMEM 43, 2 lamin A/C, 23 others). Gene–positive compared to gene–negative (n = 168, 60%) patients showed a higher prevalence of LV ejection fraction (EF)&lt;50% (14%vs.6%, p&lt;0.011), LV and RV LGE (62%vs.46%, p &lt; 0.001, 20%vs.12%, p&lt;0.02), RV dilatation (27%vs.17%, p&lt;0.041) (Table 1). DSG2 mutations were associated mainly to biventricular (7/15,46%) or RV involvement (4/15,26%), while DSP mutations to LV involvement (24/41,58%). During a median 36–month follow–up (IQ.range 12–56), 55 patients (19%) experienced the composite endpoint (35 non–sustained VT; 11 sustained VT – 3 ATP, 1 defibrillator–shock–; 9 VF, all treated by defibrillator–shock). At Kaplan–Meier analysis, DSP mutations were associated with the worst prognosis (Fig. 3). Conclusion Diverse genotypes were differently associated with LV dysfunction/LGE, RV dilatation/LGE. DSP mutations were associated with higher arrhythmic risk. Genetic screening may result in a better risk stratification, useful for clinical decision–making.

Magnetic Resonance for Differential Diagnosis of Left Ventricular Hypertrophy: Diagnostic and Prognostic Implications

BACKGROUND

Left ventricular hypertrophy (LVH) may be due to different causes, ranging from benign secondary forms to severe cardiomyopathies. Transthoracic Echocardiography (TTE) and ECG are the first-level examinations for LVH diagnosis. Cardiac magnetic resonance (CMR) accurately defines LVH type, extent and severity.

OBJECTIVES

to evaluate the diagnostic and prognostic role of CMR in patients with TTE and/or ECG evidence of LVH.

METHODS

We performed CMR in 300 consecutive patients with echocardiographic and/or ECG signs of LVH.

RESULTS

Overall, 275 patients had TTE evidence of LVH, with initial suspicion of hypertrophic cardiomyopathy (HCM) in 132 (44%), cardiac amyloidosis in 41 (14%), hypertensive LVH in 48 (16%), aortic stenosis in 4 (1%), and undetermined LVH in 50 (16%). The initial echocardiographic diagnostic suspicion of LVH was confirmed in 172 patients (57.3%) and changed in 128 patients (42.7%, p < 0.0001): the diagnosis of HCM increased from 44% to 71% of patients; hypertensive and undetermined LVH decreased significantly (respectively to 4% and 5%). CMR allowed for a diagnosis in 41 out of 50 (82%) patients with undetermined LVH at TTE. CMR also identified HCM in 17 out of 25 patients with apparently normal echocardiography but with ECG criteria for LVH. Finally, the reclassification of the diagnosis by CMR was associated with a change in survival risk of patients: after CMR reclassification, no events occurred in patients with undetermined or hypertensive LVH.

CONCLUSIONS

CMR changed echocardiographic suspicion in almost half of patients with LVH. In the subgroup of patients with abnormal ECG, CMR identified LVH (particularly HCM) in 80% of patients. This study highlights the indication of CMR to better characterize the type, extent and severity of LVH detected at echocardiography and suspected with ECG.

Myocardial T2 values by a segmental approach with healthy ageing and gender

Funding Acknowledgements

Type of funding sources: None.

Introduction. No data are available in literature about normal ranges for T2 in human myocardium using GE scanners.

Aims. Our aims were to obtain myocardial regional and global T2 values as a reference for normality for the first time using a GE scanner and to assess their association with physiological variables.

Methods. A stratified approach was adopted for healthy volunteers recruitment, ensuring the presence of 10 participants for both genders in each age decile:  20–30, 30–40, 40-50, 50-60, 60-70 years. Basal, medium, and apical short-axis slices of the left ventricle were acquired by a multi-echo fast-spin-echo (MEFSE) sequence. Image analysis was performed with a commercially available software package. T2 value was assessed in all 16 myocardial segments and global value was the mean.

Results. The global T2 value averaged across all subjects was 52.2 ± 2.5 ms (range: 47.0-59.9 ms).

Inter-study, intra-observer, and inter-observer reproducibility was good (coefficient of variation &lt; 5%).

The 3.6% of segments was excluded because of artifacts and/or partial-volume effects. Segmental T2 values differed significantly (P &lt; 0.0001), with the lowest value in the basal anterolateral segment (50.0 ± 3.5 ms) and the highest in the apical lateral segment (54.9 ± 5.1 ms). Mean T2 was significantly lower in the basal slice compared to both medium (51.0 ± 2.4  vs 51.8 ± 2.6 ms; P &lt; 0.0001) and apical slices (51.0 ± 2.4  vs 54.2 ± 3.7 ms; P &lt; 0.0001), and in the medium slice than in the apical slice (51.8 ± 2.6  vs 54.2 ± 3.7 ms; P &lt; 0.0001).

Aging was associated with increased segmental and global T2 values. Females showed higher T2 values than males. T2 values were not correlated to heart rate.

Mean T2 values, standard deviation, and lower and upper limits of normal for all 16 myocardial segments are shown in Figure 1 for males and in Figure 2 for females, considering separately each age group.

Conclusion. The optimized MEFSE sequence allows for robust, reliable, and reproducible quantification of segmental T2 values. T2 values differ among myocardial slices and are influenced by age and gender, making mandatory to define gender- and age-specific segmental reference values for distinguishing between healthy and diseased myocardium. The normal ranges defined in this study on a large cohort of healthy subjects could be used as reference by other sites using the same sequence, allowing them to recruit a smaller population and accelerating the spread of myocardial T2 mapping in the clinical arena.

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.

Influence of cardiac phase on myocardial native T1 values by a segmental approach

Funding Acknowledgements

Type of funding sources: None.

Background. Native T1 values are usually assessed in the end-diastole to minimize motion artifacts while the systolic data acquisition offers the advantage of a thicker myocardium, with reduced partial-volume effects. Higher myocardial T1 values have been detected in diastole at both 1.5T and 3T but the dependence of this difference on myocardial segments or gender has not been fully explored.

Aim. We provided a systematic comparison of myocardial native T1 values in diastole and systole, by considering separately myocardial segments and dividing males and females.

Methods. Sixty-one healthy subjects (46.0 ± 14.1 years, 32 males) underwent CMR at 1.5T (Signa Artist; GE Healthcare). Three short-axis slices of the left ventricle acquired in diastole and systole using a Modified Look–Locker Inversion Recovery sequence. Image analysis was performed with a commercially available software package. T1 value was assessed in all 16 myocardial segments and global value was the mean.

Results. Table 1 shows the comparison between T1 values calculated from maps obtained in diastole and systole. Systolic T1 values were significantly lower in the basal anterolateral segment, in all medium segments except for the medium inferior segment, and in all apical segments. The percentage difference between diastolic and systolic T1 values was considered to compensate for the higher T1 values in females, and a significantly higher value was detected in females for the majority of medium segments, for all apical segments, and for the global value.

Conclusion. The diastolic-systolic discrepancy was more pronounced for the females and at the apical level, supporting the hypothesis that, besides the physiologic variations in myocardial blood volume during the cardiac cycle, the partial volume-effect may be a strong additional contributing factor. Native T1 values should be obtained always in the same cardiac phase to avoid a potential bias in the discrimination between healthy and pathologically affected myocardium.

Comparison between echocardiography and cardiac magnetic resonance for differential diagnosis of left ventricular hypertrophy

Background

Left ventricular hypertrophy (LVH) may be due to different causes, ranging from, benign secondary forms (athlete's heart) to severe prognosis cardiomyopathies (i.e. cardiac amyloidosis). Early and accurate differential diagnosis is important to proper patient management. LVH may be detected by echocardiography signs of hypertrophy or other abnormalities often associated to hypertrophic phenotypes. Cardiac magnetic resonance (CMR) is often used to confirm the initial diagnostic suspicion. On the best of our knowledge, there are no study specifically designed to evaluate the final impact of CMR in changing or confirming the initial diagnostic echocardiographic suspicion.

Aim

To evaluate the clinical prognostic correlates of CMR in patients with echocardiographic or ECG suspicion of LVH (or cardiomyopathies with hypertrophic phenotype).

Methods and results

We enrolled 275 pts with echocardiographic evidence of LVH. Using current guidelines, the initial echocardiographic diagnostic suspicion was: hypertrophic cardiomyopathy (HCM) in 46.9% of pts; cardiac amyloidosis in 14.5%; hypertensive LVH in 17%; aortic stenosis in 1.5%; athlete's heart in 0.3%; undetermined LVH in 17%. CMR changed the diagnosis in 42% cases: the diagnosis of HCM increased from 44% to 72% of pts; hypertensive and undetermined LVH decreased significantly (respectively to 4% and 5%). Finally, the change in diagnostic suspicion was associated to reclassification of risk of patients: Kaplan-Meier curves demonstrated that HCM and cardiac amyloidosis had worst prognosis than undetermined or hypertensive LVH.

Conclusions

CMR changed the echocardiographic suspicion in almost half of patients with LVH. This study highlights the indication of CMR in patient with ECG or echocardiographic suspicion of LVH.

Kaplan-Meier curves

Funding Acknowledgement

Type of funding source: None

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).

Funding Acknowledgement

Type of funding source: None

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.

1177 The additive prognostic value of end-systolic pressure-volume relation by CMR in patients with with known or suspected coronary artery disease

Background

The variation between rest and peak stress end-systolic pressure-volume relation is an afterload-independent index of left ventricular contractility. This index is easily obtained during routine stress echocardiography but can be derived also during a stress cardiovascular magnetic resonance (CMR) exam, that is the gold standard for the quantification of biventricular volumes.

Purpose

The aim of this study was to assess for the first time the prognostic value ofdelta rest-stress ESPVR (DESPVR) by dipyridamole stress-CMR in patients with known or suspected coronary artery disease (CAD).

Methods

One hundred and sixty-six consecutive patients (37 females, main age 61.96 ± 10.05 years) who underwent dipyridamole stress-CMR in a high volume CMR Laboratory were considered. Abnormal wall motion and perfusion at rest and after dipyridamole were analysed. Macroscopic myocardial fibrosis was detected by the late gadolinium enhancement (LGE) technique. The ESPVR was evaluated at rest and peak stress from raw measurement of systolic arterial pressure by cuff sphygmomanometer and end-systolic volume by biplane Simpson method.

Results

An abnormal stress CMR was found in 39 (23.5%) patients; 24 patients had a reversible stress perfusion defect in at least one myocardial segment and 15 a reversible stress perfusion defect plus worsening of stress wall motion in comparison with rest. Myocardial fibrosis was detected in 69 patients (41.6%). A DESPVR &lt; 0.009 was detected in 74 patients (44.6%).

During a median follow up of 55.51 months (IQ range 33.20 months), 54 patients (32.5%) experienced major cardiac events: 5 deaths, 2 ventricular arrhythmias, 18 coronary syndromes, and 29 heart failure hospitalization.Reversible perfusion deficit, DESPVR &lt; 0.009, diabetes and family history were significant univariate prognosticators. In the multivariate analysisthe independent predictive factors were reversible perfusion deficit (hazard ratio-HR = 2.17, P = 0.010), DESPVR &lt; 0.009 (HR = 1.92, P = 0.028) and diabetes (HR = 2.42, P = 0.004). The Kaplan–Meier curve for DESPVR is shown in Figure 1. The log-rank test revealed a significant difference (P = 0.003).

Conclusions

DESPRV assessed by CMR provides a prognostic stratification in patients with known or suspected coronary artery disease, in addition to that supplied by reversible perfusion deficit and diabetes.

Abstract 1177 Figure 1

P5285Pressure-volume relationship by cardiovascular magnetic resonance: feasibility and clinical implications

Background

The variation between rest and peak stress end-systolic pressure-volume relation (ESPVR; the Suga index) is easily obtained during routine stress echocardiography and has been established as a reasonably load-independent index of myocardial contractile performance that provides prognostic information above and beyond regional wall motion.

Purpose

This is the first study assessing the delta rest-stress ESPVR (DESPVR) by stress Cardiovascular Magnetic Resonance (CMR).

Methods

Eighty-five consecutive patients (19 females, main age 62.99±9.26 years) who underwent dipyridamole stress-CMR in a high volume CMR Laboratory were considered. The ESPVR was evaluated at rest and peak stress from raw measurement of systolic arterial pressure by cuff sphygmomanometer and end-systolic volume by biplane Simpson method.

Results

Mean ESPVR index at rest and peak stress was, respectively, 4.52±2.26 mmHg/mL/m2 and 4.62±2.32 mmHg/mL/m2 and mean DESPVR was 0.11±1.19 mmHg/mL/m2.

DESPVR was not associated to age or sex.

An inverse relationship between rest left ventricular end-diastolic volume index (LVEDVI) and both rest and peak ESPVR was present (R=-0.805 P<0.0001 and R=-0.795 P<0.0001, respectively), but it was absent when the DESPVR was considered (R=0.170 P=0.121).

An abnormal stress CMR was found in 22 patients and the DESPVR was comparable between patients with normal and abnormal stress exam.

During a median follow-up of 60.62 months (IQ range 36.78 months), 27 cardiovascular events occurred: 3 deaths, 1 ventricular arrhythmias, 9 coronary syndromes, 14 heart failure hospitalization. At receiver-operating characteristic (ROC) curve analysis, a DESPVR<0.009 predicted the presence of future cardiac events with a sensitivity of 0.70 and a specificity of 0.64 (P=0.049).

Conclusions

We showed for the first time that dipyridamole stress CMR can be used for the assessment of DESPVR. DESPVR was shown to be independent from chamber size and, as a consequence, can be used for a comparative assessment of patients with different diseases. DESPVR by CMR can provide a prognostic stratification and the optimal cutoff for relevant events was 0.009.

Prognostic Role of Cardiac Magnetic Resonance in Arrhythmogenic Right Ventricular Cardiomyopathy

We sought to evaluate the prognostic role of cardiac magnetic resonance (CMR) in patients with definite, borderline and possible diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC) as defined by the International Task Force (TF) in 2010. CMR was performed in 175 patients: 52 with definite, 50 with borderline and 73 possible ARVC. Abnormal-CMR was defined as the presence of ≥1 CMR abnormalities (including abnormalities of right ventricular and left ventricular wall motion, fat infiltration, late gadolinium enhancement, dilation and dysfunction of either ventricles). During the follow-up time 35 patients had hard cardiac events (sudden cardiac death, appropriate implantable cardioverter defibrillator shock and resuscitated cardiac arrest), and 34 of them occurred in patients with abnormal-CMR (negative predictive value = 96.9%). At the multivariate Cox-regression analysis LV involvement at CMR (fat infiltration and/or late gadolinium enhancement), and episode of nonsustained ventricular tachycardia (NSVT) were independent predictors of cardiac events in both the whole population (LV involvement: HR 3.69, 95% CI 1.57-8.65, p = 0.0002; NSVT: HR 5.8, 95% CI 2.82-11.9, p < 0.0001), and in the group of patients with definite ARVC (LV involvement: HR 3.03, 95% CI 1.15 to 8.02, p = 0.02; NSVT: HR 12.1, 95% CI 4.02-36.5, p < 0.0001). In conclusion, CMR evidence of LV involvement is a strong independent predictor of cardiac events in patients with definite, borderline or possible ARVC diagnosis. Abnormal CMR has very high negative predictive value for hard cardiac events.