SCMR expert consensus statement for cardiovascular magnetic resonance of patients with a cardiac implantable electronic device

Cardiovascular magnetic resonance (CMR) is a proven imaging modality for informing diagnosis and prognosis, guiding therapeutic decisions, and risk stratifying surgical intervention. Patients with a cardiac implantable electronic device (CIED) would be expected to derive particular benefit from CMR given high prevalence of cardiomyopathy and arrhythmia. While several guidelines have been published over the last 16 years, it is important to recognize that both the CIED and CMR technologies, as well as our knowledge in MR safety, have evolved rapidly during that period. Given increasing utilization of CIED over the past decades, there is an unmet need to establish a consensus statement that integrates latest evidence concerning MR safety and CIED and CMR technologies. While experienced centers currently perform CMR in CIED patients, broad availability of CMR in this population is lacking, partially due to limited availability of resources for programming devices and appropriate monitoring, but also related to knowledge gaps regarding the risk-benefit ratio of CMR in this growing population. To address the knowledge gaps, this SCMR Expert Consensus Statement integrates consensus guidelines, primary data, and opinions from experts across disparate fields towards the shared goal of informing evidenced-based decision-making regarding the risk-benefit ratio of CMR for patients with CIEDs.

Risk stratification in patients with structurally normal hearts: Does fibrosis type matter?

OBJECTIVES

The study sought to assess the prognostic significance of nonischemic myocardial fibrosis (MF) on cardiovascular magnetic resonance (CMR)-both macroscopic MF assessed by late gadolinium enhancement (LGE) and diffuse microscopic MF quantified by extracellular volume fraction (ECV)-in patients with structurally normal hearts.

BACKGROUND

The clinical relevance of tissue abnormalities identified by CMR in patients with structurally normal hearts remains unclear.

METHODS

Consecutive patients undergoing CMR were screened for inclusion to identify those with LGE imaging and structurally normal hearts. ECV was calculated in patients with available T1 mapping. The associations between myocardial fibrosis and the outcomes of all-cause mortality, new-onset heart failure [HF], and an arrhythmic outcome were evaluated.

RESULTS

In total 525 patients (mean age 43.1±14.2 years; 30.5% males) were included. Over a median follow-up of 5.8 years, 13 (2.5%) patients died and 18 (3.4%) developed new-onset HF. Nonischemic midwall /subepicardial LGE was present in 278 (52.9%) patients; isolated RV insertion fibrosis was present in 80 (15.2%) patients. In 276 patients with available T1 mapping, the mean ECV was 25.5 ± 4.4%. There was no significant association between LGE and all-cause mortality (HR: 1.36, CI: 0.42-4.42, p = 0.61), or new-onset HF (HR: 0.64, CI: 0.25-1.61, p = 0.34). ECV (per 1% increase) correlated with all-cause mortality (HR: 1.19, CI: 1.04-1.36, p = 0.009), but not with new-onset HF (HR: 0.97, CI: 0.86-1.10, p = 0.66). There was no significant association between arrhythmic outcomes and LGE (p = 0.60) or ECV (p = 0.49). In a multivariable model after adjusting for covariates, ECV remained significantly associated with all-cause mortality (HR per 1% increase in ECV: 1.26, CI: 1.06-1.50, p = 0.009).

CONCLUSION

Nonischemic LGE in patients with structurally normal hearts is common and does not appear to be associated with adverse outcomes, whereas elevated ECV is associated with all-cause mortality and may be an important risk stratification tool.

Preservation of Circumferential and Radial Left Ventricular Function as a Mitigating Mechanism for Impaired Longitudinal Strain in Early Cardiac Amyloidosis

BACKGROUND

In patients with cardiac amyloidosis (CA), left ventricular ejection fraction (LVEF) is frequently preserved, despite commonly reduced global longitudinal strain (GLS). We hypothesized that nonlongitudinal contraction may initially serve as a mitigating mechanism to maintain cardiac output and studied the relationship between global circumferential (GCS) and radial (GRS) strain with LVEF and extracellular volume (ECV), a marker of amyloid burden.

METHODS

Patients with CA who underwent cardiac magnetic resonance (CMR; n = 140, 70.7 ± 11.5 years, 66% male) or echocardiography (n = 67, 71 ± 13 years, 66% male) and normal controls (CMR, n = 20; echocardiography, n = 45) were retrospectively identified, and GCS, GLS, and GRS were quantified using feature-tracking CMR or speckle-tracking echocardiography and compared between CA patients with preserved and reduced LVEF (CAHFpEF, CAHFrEF) and controls. The prevalence of impaired strain (magnitudes <2.5th percentile of the controls) was compared between CAHFpEF and CAHFrEF and between ECV quartiles.

RESULTS

While echocardiography-derived GLS was impaired in both CAHFpEF (-13.4% ± 3.1%, P < .003) and CAHFrEF (-9.1% ± 3.2%, P < .003), compared with controls (-20.8% ± 2.4%), GCS was more impaired in CAHFrEF compared with both controls (-15.6% ± 5.0% vs -32.3% ± 3.3%, P < .003) and CAHFpEF (-30.4% ± 5.7%, P < .003) and did not differ between CAHFpEF and controls (P = .24). The prevalence of abnormal CMR-derived GCS (P < .0001) and GRS (P < .0001) but not GLS (P = .054) varied significantly across ECV quartiles.

CONCLUSIONS

Among CA patients with preserved LVEF, preserved GCS and GRS, despite near-universally impaired GLS, may be explained by an initial predominantly subendocardial involvement, where mostly longitudinal fibers are located. If confirmed in future studies, these findings may facilitate identification of patients with early stages of CA, when treatments may be most effective.

Parametric mapping by cardiovascular magnetic resonance imaging in sudden cardiac arrest survivors

Etiology of sudden cardiac arrest (SCA) is identified in less than 30% of survivors without coronary artery disease. We sought to assess the diagnostic role of myocardial parametric mapping using cardiovascular magnetic resonance (CMR) in identifying SCA etiology. Consecutive SCA survivors undergoing CMR with myocardial parametric mapping were included in the study. The determination if CMR was decisive or contributory in identifying SCA etiology was made if the diagnosis was unclear prior to CMR, and the discharge diagnosis was consistent with the CMR result. Parametric mapping was considered essential for establishing probable SCA etiology by CMR if the SCA cause could not have been determined without its utilization. If the CMR diagnosis could have been potentially based on the combination of cine and LGE imaging, parametric mapping was considered contributory. Of the 35 patients (mean age 46.9 ± 14.1 years; 57% males) included, SCA diagnosis was based on CMR in 23 (66%) patients. Of those, parametric mapping was essential for the diagnosis of myocarditis and tako-tsubo cardiomyopathy (11/48%) and contributed to the diagnosis in 10 (43%) additional cases. Inclusion of quantitative T1 and T2 parametric mapping in the SCA CMR protocol has the potential to increase diagnostic yield of CMR and further specify SCA etiology, especially myocarditis.

Non-invasive diagnosis of transthyretin cardiac amyloidosis utilizing typical late gadolinium enhancement pattern on cardiac magnetic resonance and light chains

AIMS

While cardiac magnetic resonance (CMR) is often obtained early in the evaluation of suspected cardiac amyloidosis (CA), it currently cannot be utilized to differentiate immunoglobulin (AL) and transthyretin (ATTR) CA. We aimed to determine whether a novel CMR and light-chain biomarker-based algorithm could accurately diagnose ATTR-CA.

METHODS AND RESULTS

Patients with confirmed AL or ATTR-CA with typical late gadolinium enhancement (LGE) and Look-Locker pattern for CA on CMR were retrospectively identified at three academic medical centres. Comprehensive light-chain analysis including free light chains, serum, and urine electrophoresis/immunofixation was performed. The diagnostic accuracy of the typical CMR pattern for CA in combination with negative light chains for the diagnosis of ATTR-CA was determined both in the entire cohort and in the subset of patients with invasive tissue biopsy as the gold standard. A total of 147 patients (age 70 ± 11, 76% male, 51% black) were identified: 89 ATTR-CA and 58 AL-CA. Light-chain biomarkers were abnormal in 81 (55%) patients. Within the entire cohort, the sensitivity and specificity of a typical LGE and Look-Locker CMR pattern and negative light chains for ATTR-CA was 73 and 98%, respectively. Within the subset with biopsy-confirmed subtype, the CMR and light-chain algorithm were 69% sensitive and 98% specific.

CONCLUSION

The combination of a typical LGE and Look-Locker pattern on CMR with negative light chains is highly specific for ATTR-CA. The successful non-invasive diagnosis of ATTR-CA using CMR has the potential to reduce diagnostic and therapeutic delays and healthcare costs for many patients.

T2 mapping in myocardial disease: a comprehensive review

Cardiovascular magnetic resonance (CMR) is considered the gold standard imaging modality for myocardial tissue characterization. Elevated transverse relaxation time (T2) is specific for increased myocardial water content, increased free water, and is used as an index of myocardial edema. The strengths of quantitative T2 mapping lie in the accurate characterization of myocardial edema, and the early detection of reversible myocardial disease without the use of contrast agents or ionizing radiation. Quantitative T2 mapping overcomes the limitations of T2-weighted imaging for reliable assessment of diffuse myocardial edema and can be used to diagnose, stage, and monitor myocardial injury. Strong evidence supports the clinical use of T2 mapping in acute myocardial infarction, myocarditis, heart transplant rejection, and dilated cardiomyopathy. Accumulating data support the utility of T2 mapping for the assessment of other cardiomyopathies, rheumatologic conditions with cardiac involvement, and monitoring for cancer therapy-related cardiac injury. Importantly, elevated T2 relaxation time may be the first sign of myocardial injury in many diseases and oftentimes precedes symptoms, changes in ejection fraction, and irreversible myocardial remodeling. This comprehensive review discusses the technical considerations and clinical roles of myocardial T2 mapping with an emphasis on expanding the impact of this unique, noninvasive tissue parameter.

Prevalence and haemodynamic profiles of pulmonary hypertension in cardiac amyloidosis

OBJECTIVES

While cardiac amyloidosis (CA) classically involves the left ventricle (LV), less is known about its impact on the right ventricle (RV) and pulmonary vasculature. We performed a retrospective analysis to identify the prevalence and types of pulmonary hypertension (PH) profiles in CA and to determine haemodynamic and cardiovascular magnetic resonance (CMR) predictors of major adverse cardiovascular events (MACE).

METHODS

Patients with CA who underwent CMR and right heart catheterisation (RHC) within 1 year between 2010 and 2019 were included. Patients were assigned the following haemodynamic profiles based on RHC: no PH, precapillary PH, isolated postcapillary PH (IPCPH), or combined precapillary and postcapillary PH (CPCPH). The relationship between PH profile and MACE (death, heart failure hospitalisation) was assessed using survival analysis. CMR and RV parameters were correlated with MACE using Cox-regression analysis.

RESULTS

A total of 52 patients were included (age 69±9 years, 85% men). RHC was performed during biopsy in 44 (85%) and for clinical indications in 8 (15%) patients. Rates of no PH, precapillary PH, IPCPH and CPCPH were 5 (10%), 3 (6%), 29 (55%) and 15 (29%), respectively. Haemodynamic PH profile did not correlate with risk of death (p=0.98) or MACE (p=0.67). Transpulmonary gradient (TPG) (HR 0.88, CI 0.80 to 0.97), RV, (HR 0.95, CI 0.92 to 0.98) and LV ejection fraction (HR 0.95, CI 0.92 to 0.98) were significantly associated with MACE.

CONCLUSIONS

PH is highly prevalent in CA, even at the time of diagnosis. While IPCPH was most common, CPCPH is not infrequent. TPG and RV ejection fraction (RVEF) are prognostic markers in this population.

Validating an Idiopathic Dilated Cardiomyopathy Diagnosis Using Cardiovascular Magnetic Resonance: The Dilated Cardiomyopathy Precision Medicine Study

BACKGROUND

Coronary angiography to identify coronary artery disease has been foundational to distinguish the cause of dilated cardiomyopathy (DCM), including the assignment of idiopathic or ischemic cardiomyopathy. Late gadolinium enhancement (LGE) with cardiovascular magnetic resonance (CMR) has emerged as an approach to identify myocardial scar and identify etiology.

METHODS

The DCM Precision Medicine Study included patients with left ventricular dilation and dysfunction attributed to idiopathic DCM, after expert clinical review excluded ischemic or other cardiomyopathies. Ischemic cardiomyopathy was defined as coronary artery disease with >50% narrowing at angiography of ≥1 epicardial coronary artery. CMR was not required for study inclusion, but in a post hoc analysis of available CMR reports, patterns of LGE were classified as (1) no LGE, (2) ischemic-pattern LGE: subendocardial/transmural, (3) nonischemic LGE: midmyocardial/epicardial.

RESULTS

Of 1204 idiopathic DCM patients evaluated, 396 (32.9%) had a prior CMR study; of these, 327 (82.6% of 396) had LGE imaging (mean age 46 years; 53.2% male; 55.4% White); 178 of the 327 (54.4%) exhibited LGE, and 156 of the 178 had LGE consistent with idiopathic DCM. The remaining 22 had transmural or subendocardial LGE. Of these 22, coronary angiography was normal (13), showed luminal irregularities (3), a distant thrombus (1), coronary artery disease with <50% coronary artery narrowing (1), or was not available (4).

CONCLUSIONS

Of 327 probands enrolled in the DCM Precision Medicine Study cohort who had LGE-CMR data available, an ischemic-pattern of LGE was identified in 22 (6.7%), all of whom had idiopathic DCM as adjudicated by expert clinical review.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03037632.

Atrial function and geometry differences in transthyretin versus immunoglobulin light chain amyloidosis: a cardiac magnetic resonance study

To determine the differences in left atrial (LA) function and geometry assessed by cardiac magnetic resonance (CMR) between transthyretin (ATTR) and immunoglobulin light chain (AL) cardiac amyloidosis (CA). We performed a retrospective analysis of 54 consecutive patients (68.5% male, mean age 67 ± 11 years) with confirmed CA (24 ATTR, 30 AL) who underwent comprehensive CMR examinations. LA structural and functional assessment including LA volume, LA sphericity index, and LA strain parameters were compared between both subtypes. In addition, 15 age-matched controls were compared to all groups. Patients with ATTR-CA were older (73 ± 9 vs. 62 ± 10 years, p < 0.001) and more likely to be male (83.3% vs. 56.7%, p = 0.036) when compared to AL-CA. No significant difference existed in LA maximum volume and LA sphericity index between ATTR-CA and AL-CA. LA minimum volumes were larger in ATTR-CA when compared with AL-CA. There was a significant difference in LA function with worse strain values in ATTR vs AL: left atrial reservoir [7.4 (6.3–12.8) in ATTR vs. 13.8 (6.90–24.8) in AL, p = 0.017] and booster strains [3.6 (2.6–5.5) in ATTR vs. 5.2 (3.6–12.1) in AL, p = 0.039]. After adjusting for age, LA reservoir remained significantly lower in ATTR-CA compared to AL-CA (p = 0.03), but not LA booster (p = 0.16). We demonstrate novel differences in LA function between ATTR-CA and AL-CA despite similar LA geometry. Our findings of more impaired LA function in ATTR may offer insight into higher AF burden in these patients.

The role of cardiovascular magnetic resonance imaging with T1 and T2 mapping in sudden cardiac death survivors

Background

Sudden cardiac death (SCD) in the adult population is poorly studied, although determining its etiology is crucial for management and prognosis [1]. Cardiovascular magnetic resonance imaging (CMR) is being increasingly utilized in SCD survivors [1,2]. The role of late gadolinium enhancement (LGE) imaging in patients with recent SCD and no significant coronary artery disease (CAD) is well established, but there is no data on the additive role of T1 and T2 mapping [1–3].

Purpose

This is a retrospective study to assess the role of CMR including T1 and T2 mapping in SCD survivors.

Methods

Between 01/2016 and 12/2019, we retrospectively analyzed patients who underwent CMR on a Siemens Magnetom Avanto 1.5 T scanner within 4 weeks of SCD. CMR protocol included cine imaging, T1 and T2 mapping, and LGE imaging. Native and post-contrast myocardial T1 values were measured within the septum on the mid short axis (SAX) and extracellular volume fraction was calculated using the standard formula. T2 values were measured in six mid segments on the mid SAX map. Additional measurements were performed if long axis T2 maps were available. Clinical data, electrocardiography (ECG), transthoracic echocardiography (TTE), coronary computed tomography angiography (CCTA), and left heart catheterization (LHC) were reviewed from the electronic health record. An ischemic evaluation was performed in 33 (94%) of patients.

Results

A total of 35 patients who underwent CMR for SCD were included for analysis (mean age 46.9±14.1 years; 20 (57%) male). SCD etiology was established based on clinical data, ECG, TTE, CCTA, and LHC in 9 (26%) patients. CMR provided the most probable SCD etiology in an additional 20 (57%) patients with T1 and T2 mapping abnormalities seen in 18 (51%) patients. Diagnoses determined by CMR included myocarditis (35%), hypertrophic cardiomyopathy (CMP) (20%), left ventricular non-compaction CMP (15%), dilated CMP (10%), takotsubo CMP (5%), and myocardial infarction with non-obstructive CAD (15%) (Table, Figure). Elevated native T1 was seen in 15 (43%) (mean T1 1069±60 ms; site specific normal &lt;1080 ms), elevated ECV in 16 (46%) (30±7%; site specific normal &lt;29%), and elevated native T2 in 22 (63%) patients (65±10 ms; site specific normal &lt;60 ms). LGE was present in 31 (89%) patients. The etiology of SCD remained unknown in 6 (17%) patients despite extensive testing including CMR.

Conclusions

CMR has significant diagnostic and prognostic value in assessing SCD etiology compared to non-CMR based evaluation. Myocarditis is a common underdiagnosed cause of SCD in adult patients well seen in a CMR protocol with T1 and T2 mapping. Myocardial inflammation monitoring in SCD survivors with serial CMRs using T1 and T2 mapping could influence clinical decision making by justifying pharmacotherapy modification and timing of ICD implantation. To conclude, CMR with T1 and T2 mapping provides high diagnostic yield in the investigation of SCD etiology.

Funding Acknowledgement

Type of funding sources: None.

Rapid cardiovascular magnetic resonance protocol utilizing compressed sensing real-time imaging during the COVID-19 pandemic

Funding Acknowledgements

Type of funding sources: None.

Background

Coronavirus Disease 2019 (COVID-19) poses many workflow challenges for healthcare systems. Elective cardiovascular magnetic resonance (CMR) exams were postponed until safety protocols were instituted. Since reopening, imaging labs are managing COVID-19 safety triaging, exam backlog, and increased referrals, thus innovative solutions for process improvement are needed.

Purpose

An accelerated compressed sensing (CS) real-time (RT) technique offers dynamic cardiac imaging with high spatial and temporal resolution without image degradation. We sought to evaluate the efficiency of a rapid RT CMR protocol with a goal to decrease scan time without compromising study quality and comprehensiveness.

Methods

We retrospectively evaluated 219 CMRs (Siemens Magnetom Sola 1.5T) performed 09/01/2020 - 10/15/2020. After excluding 81 exams due to heterogeneous protocols (Figure 1), we analyzed 138 CMR exams using standard cardiomyopathy or myocarditis protocols. CMR studies utilized either a rapid RT short axis (SAX) cine (spatial resolution of 2.5 mm2 or better and temporal resolution of 55 ms or better) or standard breath-held (BH) SAX cine protocol (Figure 2).  Protocols were chosen by the interpreting physician. Previous internal quality control demonstrated similar volumetric quantification between RT and BH SAX cines. RT cines were reconstructed inline using a CS-based method.  We analyzed the length of time needed to complete each protocol and the number of series performed. Statistical analysis included student t-test with p value &lt;0.05 considered significant.

Results

Of 138 analyzed CMR exams, there were 23 rapid protocols and 115 standard protocols performed. The mean image acquisition time for the rapid protocol was significantly shorter at 26 ± 6 minutes (range 18-44 min) vs 33 ± 6 minutes (range 22-49 min) for the standard protocol, p &lt; 0.001. This represents a mean relative reduction in scan time of 21%. More time was saved in rapid myocarditis (scan time 25 ± 6 min vs 34 ± 6 min, p = 0.01; relative time reduction 26%) vs rapid cardiomyopathy protocols (scan time 27 ± 6 min vs 31 ± 6 min, p = 0.04; relative time reduction 13%). There was no significant difference in the number of series performed (62 ± 14 series in rapid vs 67 ± 11 series in standard protocols, p = 0.09).  T1 and T2 maps constituted the same percentage of acquired images regardless of protocol used (T1 maps 1.8% vs 1.7% for cardiomyopathy, 1.4% vs 1.4% for myocarditis in standard vs rapid protocols respectively; T2 maps 1.8% vs 1.7% for cardiomyopathy, 5.6% vs 5.8% for myocarditis in standard vs rapid protocols respectively).

Conclusions

A rapid CMR protocol utilizing a CS-based RT imaging is significantly shorter as compared to the standard protocol with adequate diagnostic quality. Rapid CMR protocols are an effective tool for process improvement during the COVID-19 pandemic.

Inherited Variants in SCARB1 Cause Severe Early-Onset Coronary Artery Disease

[Figure: see text].

Normal left atrial strain and strain rate using cardiac magnetic resonance feature tracking in healthy volunteers

AIMS

The aim of our study was to establish normal ranges for left atrial (LA) strain and strain rate using cardiac magnetic resonance feature tracking (CMR-FT), LA sphericity index, and to compare LA strain using CMR-FT with 2D-speckle tracking echocardiography (STE) in a healthy population.

METHODS AND RESULTS

A total of 112 volunteers (45 male, 67 female) had adequate tracking for analysis on CMR-FT (Circle Cardiovascular Imaging, Calgary, Canada). The median age was 42 years (range 19-79 years, interquartile range 30-53 years). LA reservoir, conduit, booster strain, strain rate using CMR-FT, and sphericity index were evaluated. Of the 112 volunteers, 91 patients had adequate tracking on 2D-STE using three commonly applied zero-baseline time reference methods: R-R gating, P-P gating, and volume gating (defining end-systole at the LA maximum and end-diastole at the LA minimum). The LA strain, strain rate using CMR-FT, and sphericity index were reported and comparable between both genders (P > 0.05 for all). The LA booster function including strain and strain rate increased significantly with age (P < 0.001 for all), while the LA conduit function gradually decreased. In comparison with STE, the LA reservoir strain was comparable between CMR and volume-gating methods (38.48 ± 9.31 vs. 36.77 ± 6.46; P = 0.13) but not with R-R and P-P gating methods (P < 0.001 for all). LA strain, strain rate, and sphericity index using CMR-FT had good intraobserver and interobserver reproducibility.

CONCLUSION

LA strain, strain rate using CMR-FT, and sphericity index can be quickly assessed with good intraobserver and interobserver reproducibility.

T-wave and its association with myocardial fibrosis on cardiovascular magnetic resonance examination

Background

Risk stratification in non‐ischemic myocardial disease poses a challenge. While cardiovascular magnetic resonance (CMR) is a comprehensive tool, the electrocardiogram (ECG) provides quick impactful clinical information. Studying the relationships between CMR and ECG can provide much‐needed risk stratification. We evaluated the electrocardiographic signature of myocardial fibrosis defined as presence of late gadolinium enhancement (LGE) or extracellular volume fraction (ECV) ≥29%.

Methods

We evaluated 240 consecutive patients (51% female, 47.1 ± 16.6 years) referred for a clinical CMR who underwent 12‐lead ECGs within 90 days. ECG parameters studied to determine association with myocardial fibrosis included heart rate, QRS amplitude/duration, T‐wave amplitude, corrected QT and QT peak, and Tpeak‐Tend. Abnormal T‐wave was defined as low T‐wave amplitude ≤200 µV or a negative T wave, both in leads II and V5.

Results

Of the 147 (61.3%) patients with myocardial fibrosis, 67 (28.2%) had ECV ≥ 29%, and 132 (54.6%) had non‐ischemic LGE. An abnormal T‐wave was more prevalent in patients with versus without myocardial fibrosis (66% versus 42%, p < .001). Multivariable analysis demonstrated that abnormal T‐wave (OR 1.95, 95% CI 1.09–3.49, p = .03) was associated with myocardial fibrosis (ECV ≥ 29% or LGE) after adjustment for clinical covariates (age, gender, history of hypertension, and heart failure). Dynamic nomogram for predicting myocardial fibrosis using clinical parameters and the T‐wave was developed: https://normogram.shinyapps.io/CMR_Fibrosis/.

Conclusion

Low T‐wave amplitude ≤ 200 µV or negative T‐waves are independently associated with myocardial fibrosis. Prospective evaluation of T‐wave amplitude may identify patients with a high probability of myocardial fibrosis and guide further indication for CMR.

Indexed left ventricular mass to QRS voltage ratio is associated with heart failure hospitalizations in patients with cardiac amyloidosis

In cardiac amyloidosis (CA), amyloid infiltration results in increased left ventricular (LV) mass disproportionate to electrocardiographic (EKG) voltage. We assessed the relationship between LV mass-voltage ratio with subsequent heart failure hospitalization (HHF) and mortality in CA. Patients with confirmed CA and comprehensive cardiovascular magnetic resonance (CMR) and EKG exams were included. CMR-derived LV mass was indexed to body surface area. EKG voltage was assessed using Sokolow, Cornell, and Limb-voltage criteria. The optimal LV mass-voltage ratio for predicting outcomes was determined using receiver operating characteristic curve analysis. The relationship between LV mass-voltage ratio and HHF was assessed using Cox proportional hazards analysis adjusting for significant covariates. A total of 85 patients (mean 69 ± 11 years, 22% female) were included, 42 with transthyretin and 43 with light chain CA. At a median of 3.4-year follow-up, 49% of patients experienced HHF and 60% had died. In unadjusted analysis, Cornell LV mass-voltage ratio was significantly associated with HHF (HR, 1.05; 95% CI 1.02-1.09, p = 0.001) and mortality (HR, 1.05; 95% CI 1.02-1.07, p = 0.001). Using ROC curve analysis, the optimal cutoff value for Cornell LV mass-voltage ratio to predict HHF was 6.7 gm/m2/mV. After adjusting for age, NYHA class, BNP, ECV, and LVEF, a Cornell LV mass-voltage ratio > 6.7 gm/m2/mV was significantly associated with HHF (HR 2.25, 95% CI 1.09-4.61; p = 0.03) but not mortality. Indexed LV mass-voltage ratio is associated with subsequent HHF and may be a useful prognostic marker in cardiac amyloidosis.

Right Atrial Deformation Using Cardiovascular Magnetic Resonance Myocardial Feature Tracking Compared with Two-Dimensional Speckle Tracking Echocardiography in Healthy Volunteers

Speckle tracking echocardiography (STE), and more recently, cardiovascular magnetic resonance myocardial feature tracking (CMR-FT) provides insight into all phases of atrial function. The aim of our study was to compare all phases of RA strain using CMR-FT and STE and also assess the relationship between RA and LA strain. A total of 61 healthy volunteers with mean age of 45 ± 13 years had adequate tracking for analysis on CMR-FT and 2D-STE. Females had larger RA reservoir strain (39 ± 15% vs. 32 ± 13%, p = 0.046) and conduit strain (26 ± 12% vs. 20 ± 9%, p = 0.03) when compared to males, but was not the case with booster strain (14 ± 7% vs. 12 ± 6%, p = 0.45). In comparison with STE derived strain, the RA reservoir and conduit strain were not significantly different between CMR-FT and the three echocardiography gating methods (p > 0.05 for all). Noticeably, there were no significant differences in strain and strain rate between RA and LA function using CMR-FT (p > 0.05 for all). RA strain and strain rate using CMR-FT had fair and good intra- and inter-observer reproducibility and had superior reproducibility compared to STE derived strain.

Myocardial fibrosis by late gadolinium enhancement cardiovascular magnetic resonance in myotonic muscular dystrophy type 1: highly prevalent but not associated with surface conduction abnormality

BACKGROUND

Conduction disease and arrhythmias represent a major cause of mortality in myotonic muscular dystrophy type 1 (MMD1). Permanent pacemaker (PPM) implantation is the cornerstone of therapy to reduce cardiovascular mortality in MMD1. Cardiovascular magnetic resonance (CMR) studies demonstrate a high prevalence of myocardial fibrosis in MMD1, however the association between CMR myocardial fibrosis with late gadolinium enhancement (CMR-LGE) and surface conduction abnormality is not well established in MMD1. We investigated whether myocardial fibrosis by CMR-LGE is associated with surface conduction abnormalities meeting criteria for PPM implantation according to current guidelines in a cohort of patients with genetically confirmed MMD1.

METHODS

Patients with genetically confirmed MMD1 were retrospectively evaluated. 12-lead electrocardiography (ECG) performed within 6 months of CMR was necessary for inclusion. The severity and extent of MMD1 was quantified using a validated Muscular Impairment Rating Scale (MIRS). Based on current guidelines for device-based therapy of cardiac rhythm abnormalities, we defined surface conduction abnormality as the presence of ECG alterations meeting criteria for PPM implant (class I or II indications): PR interval > 200 ms (type I atrioventricular (AV) block) and/or mono or bifascicular block (QRS > 120 ms), or evidence of advanced AV block. Balanced steady-state free precession sequences (bSSFP) were used for assessment of left ventricular (LV) volumes and ejection fraction. MOdified Look-Locker Inversion Recovery (MOLLI) acquisition schemes were used to acquire T1 maps. Patients' charts were reviewed up to 12 months post-CMR for occurrence of PPM implantation.

RESULTS

Fifty-two patients (38% male, 41 ± 14 years) were included. Overall, 31 (60%) patients had a surface conduction abnormality and 22 (42%) demonstrated midwall myocardial fibrosis by CMR-LGE. After a median of 57 days from CMR exam, 15 patients (29%) underwent PPM implantation. Subjects with vs. without surface conduction abnormality had significantly longer disease length (15.5 vs. 7.8 years, p = 0.015) and higher disease severity on the MIRS scale (p = 0.041). High prevalence of myocardial fibrosis by CMR-LGE was detected in subjects with and without surface conduction abnormality with no significant difference between the two cohorts (42% vs. 43%, p = 0.999). By multivariate logistic regression analysis, disease length was the only independent variable associated with surface conduction abnormality (OR 1.071, 95%CI 1.003-1.144, p = 0.040); while CMR-LGE was not associated with conduction abnormality (ρ = - 0.009, p = 0.949).

CONCLUSIONS

Myocardial fibrosis by CMR-LGE is highly prevalent in MMD1 but not related to surface conduction abnormality meeting current guideline criteria for PPM implantation .

Is mitral valve disease treated differently in men and women?

PURPOSE

This study was performed to determine if there is a sex-based bias in referral practices, complexity of disease, surgical treatment, or outcomes in patients undergoing mitral valve surgery at our institution.

METHODS

Data were collected from the Cardiovascular Research Database of the Clinical Trial Unit of the Bluhm Cardiovascular Institute at Northwestern Memorial Hospital and they were defined according to the Society of Thoracic Surgeons National Database ( www.sts.org ). All patients who had mitral valve replacement, mitral valve repair with annuloplasty ring placement, and mitral valve annuloplasty alone were evaluated, including patients who underwent concomitant tricuspid valve surgery, atrial fibrillation ablation, patent foramen ovale closure, and coronary artery bypass grafting. An unmatched comparison was made between the 836 men and 600 women in the entire cohort (N = 1436) and propensity score-matching was performed in 423 pairs of men and women. Additional propensity score-matching for 219 pairs of men and women with Type II mitral valve functional class and no coronary artery disease and for 68 pairs of men and women with Type 1 or Type IIIb mitral valve functional class. Propensity score matching was used to compare sex differences involving a greedy algorithm with a caliper of size 0.1 logit propensity score standard deviation units.

RESULTS

Between 1 April 2004 and 30 June 2017, 1436 patients (41.8% women, mean age 61.1 ± 12.6 years (men), 62.9 ± 13.3 years (women)) underwent mitral valve surgery. The unmatched comparison for the entire cohort showed that, on average, at the time of surgery, women had higher Society of Thoracic Surgery risk scores, were older and had more heart failure, coronary artery disease, and mitral stenosis than men. Women received proportionately fewer mitral repairs and more atrial fibrillation ablation, and tricuspid valve surgery. Women had longer intensive care unit and hospital stays, required more dialysis, and suffered more transient ischemic attacks and cardiac arrests postoperatively, and 30-day mortality rate was higher for women. However, propensity score-matching of 846 of the patients (423 men; 423 women) indicated that both the surgical approaches and surgical outcomes were comparable for men and women who had similar levels of disease and co-morbidities. Additional propensity score-matching of only those patients with degenerative mitral regurgitation (DMR) (219 men; 219 women) and those with Type 1 or Type III mitral valve disease showed no differences in the surgical procedures performed or in 30-day mortality rates.

CONCLUSIONS

Women appear to be referred for mitral valve surgery later in the course of their disease, which could possibly be on the basis of sex bias, but they may also have a more aggressive form of mitral valve disease than men. Regardless of the reasons for the later referral of women for mitral valve surgery, the clinical outcomes are dependent upon the severity of the mitral disease and associated co-morbidities at the time of surgery, not on the basis of sex bias.

T-Wave Abnormality as Electrocardiographic Signature of Myocardial Edema in Non-ST-Elevation Acute Coronary Syndromes

Background

T‐wave abnormalities are common during the acute phase of non‐ST‐segment elevation acute coronary syndromes, but mechanisms underlying their occurrence are unclear. We hypothesized that T‐wave abnormalities in the presentation of non‐ST‐segment elevation acute coronary syndromes correspond to the presence of myocardial edema.

Methods and Results

Secondary analysis of a previously enrolled prospective cohort of patients presenting with non‐ST‐segment elevation acute coronary syndromes was conducted. Twelve‐lead electrocardiography (ECG) and cardiac magnetic resonance with T2‐weighted imaging were acquired before invasive coronary angiography. ECGs were classified dichotomously (ie, ischemic versus normal/nonischemic) and nominally according to patterns of presentation: no ST‐ or T‐wave abnormalities, isolated T‐wave abnormality, isolated ST depression, ST depression+T‐wave abnormality. Myocardial edema was determined by expert review of T2‐weighted images. Of 86 subjects (65% male, 59.4 years), 36 showed normal/nonischemic ECG, 25 isolated T‐wave abnormalities, 11 isolated ST depression, and 14 ST depression+T‐wave abnormality. Of 30 edema‐negative subjects, 24 (80%) had normal/nonischemic ECGs. Isolated T‐wave abnormality was significantly more prevalent in edema‐positive versus edema‐negative subjects (41.1% versus 6.7%, P=0.001). By multivariate analysis, an ischemic ECG showed a strong association with myocardial edema (odds ratio 12.23, 95% confidence interval 3.65‐40.94, P<0.0001). Among individual ECG profiles, isolated T‐wave abnormality was the single strongest predictor of myocardial edema (odds ratio 23.84, 95% confidence interval 4.30‐132, P<0.0001). Isolated T‐wave abnormality was highly specific (93%) but insensitive (43%) for detecting myocardial edema.

Conclusions

T‐wave abnormalities in the setting of non‐ST‐segment elevation acute coronary syndromes are related to the presence of myocardial edema. High specificity of this ECG alteration identifies a change in ischemic myocardium associated with worse outcomes that is potentially reversible.

The role of stress cardiac magnetic resonance in women

Coronary artery disease (CAD) is the leading cause of death in women. Nevertheless, extensive evidence demonstrates under-diagnosis and under-treatment of women for suspected or known ischemic heart disease (IHD). Stress cardiac magnetic resonance (CMR) is becoming readily available and offers significant advantages over other stress imaging modalities. The high spatial and temporal resolution of CMR provides the unique ability to identify subendocardial ischemia, viability, and the presence of microvascular disease. Furthermore, CMR is free from ionizing radiation, and image quality is not compromised by attenuation artifacts or patient size. Over the past two decades, evidence-based data have demonstrated the high diagnostic and prognostic performance of stress CMR in the context of IHD, often superior to other stress imaging techniques. Importantly, ad hoc studies confirmed these results in women with known or suspected IHD. Stress CMR warrants consideration as the modality of choice for women requiring an imaging test for ischemia given its strong evidence base, superior test characteristics, comprehensive nature, and unique ability to characterize both epicardial and microvascular disease.

Myocardial Fibrosis Quantified by Extracellular Volume Is Associated With Subsequent Hospitalization for Heart Failure, Death, or Both Across the Spectrum of Ejection Fraction and Heart Failure Stage

BACKGROUND

Myocardial fibrosis (MF) in noninfarcted myocardium may be an interstitial disease pathway that confers vulnerability to hospitalization for heart failure, death, or both across the spectrum of heart failure and ejection fraction. Hospitalization for heart failure is an epidemic that is difficult to predict and prevent and requires potential therapeutic targets associated with outcomes.

METHOD AND RESULTS

We quantified MF with cardiovascular magnetic resonance extracellular volume fraction (ECV) measures in 1172 consecutive patients without amyloidosis or hypertrophic or stress cardiomyopathy and assessed associations with outcomes using Cox regression. ECV ranged from 16.6% to 47.8%. Over a median of 1.7 years, 111 patients experienced events after cardiovascular magnetic resonance, 55 had hospitalization for heart failure events, and there were 74 deaths. ECV was more strongly associated with outcomes than "nonischemic" MF observed with late gadolinium enhancement, thus ECV quantified MF in multivariable models. Adjusting for age, sex, renal function, myocardial infarction size, ejection fraction, hospitalization status, and heart failure stage, higher ECV was associated with hospitalization for heart failure (hazard ratio 1.77; 95% CI 1.32 to 2.36 for every 5% increase in ECV), death (hazard ratio 1.87 95% CI 1.45 to 2.40) or both (hazard ratio 1.85, 95% CI 1.50 to 2.27). ECV improved classification of persons at risk and improved model discrimination for outcomes (eg, hospitalization for heart failure: continuous net reclassification improvement 0.33, 95% CI 0.05 to 0.66; P=0.02; 0.16, 95% CI 0.01 to 0.33; P=0.02; integrated discrimination improvement 0.037, 95% CI 0.008 to 0.073; P<0.01).

CONCLUSION

MF measured by ECV is associated with hospitalization for heart failure, death, or both. MF may represent a principal phenotype of cardiac vulnerability that improves risk stratification. Because MF can be reversible, cells and enzymes regulating collagen could be potential therapeutic targets.

Myocardial damage detected by late gadolinium enhancement cardiovascular magnetic resonance is associated with subsequent hospitalization for heart failure

BACKGROUND

Hospitalization for heart failure (HHF) is among the most important problems confronting medicine. Late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) robustly identifies intrinsic myocardial damage. LGE may indicate inherent vulnerability to HHF, regardless of etiology, across the spectrum of heart failure stage or left ventricular ejection fraction (LVEF).

METHODS AND RESULTS

We enrolled 1068 consecutive patients referred for CMR where 448 (42%) exhibited LGE. After a median of 1.4 years (Q1 to Q3: 0.9 to 2.0 years), 57 HHF events occurred, 15 deaths followed HHF, and 43 deaths occurred without antecedent HHF (58 total deaths). Using multivariable Cox regression adjusting for LVEF, heart failure stage, and other covariates, LGE was associated with first HHF after CMR (HR: 2.70, 95% CI: 1.32 to 5.50), death (HR: 2.13, 95% CI: 1.08 to 4.21), or either death or HHF (HR: 2.52, 95% CI: 1.49 to 4.25). Quantifying LGE extent yielded similar results; more LGE equated higher risks. LGE improved model discrimination (IDI: 0.016, 95% CI: 0.005 to 0.028, P=0.002) and reclassification of individuals at risk (continuous NRI: 0.40, 95% CI: 0.05 to 0.70, P=0.024). Adjustment for competing risks of death that shares common risk factors with HHF strengthened the LGE and HHF association (HR: 4.85, 95% CI: 1.40 to 16.9).

CONCLUSIONS

The presence and extent of LGE is associated with vulnerability for HHF, including higher risks of HHF across the spectrum of heart failure stage and LVEF. Even when LVEF is severely decreased, those without LGE appear to fare reasonably well. LGE may enhance risk stratification for HHF and may enhance both clinical and research efforts to reduce HHF through targeted treatment.

Free-breathing, motion-corrected late gadolinium enhancement is robust and extends risk stratification to vulnerable patients

BACKGROUND

Routine clinical use of novel free-breathing, motion-corrected, averaged late-gadolinium-enhancement (moco-LGE) cardiovascular MR may have advantages over conventional breath-held LGE (bh-LGE), especially in vulnerable patients.

METHODS AND RESULTS

In 390 consecutive patients, we collected bh-LGE and moco-LGE with identical image matrix parameters. In 41 patients, bh-LGE was abandoned because of image quality issues, including 10 with myocardial infarction. When both were acquired, myocardial infarction detection was similar (McNemar test, P=0.4) with high agreement (κ=0.95). With artifact-free bh-LGE images, pixelwise myocardial infarction measures correlated highly (R(2)=0.96) without bias. Moco-LGE was faster, and image quality and diagnostic confidence were higher on blinded review (P<0.001 for all). During a median of 1.2 years, 20 heart failure hospitalizations and 18 deaths occurred. For bh-LGE, but not moco-LGE, inferior image quality and bh-LGE nonacquisition were linked to patient vulnerability confirmed by adverse outcomes (log-rank P<0.001). Moco-LGE significantly stratified risk in the full cohort (log-rank P<0.001), but bh-LGE did not (log-rank P=0.056) because a significant number of vulnerable patients did not receive bh-LGE (because of arrhythmia or inability to hold breath).

CONCLUSIONS

Myocardial infarction detection and quantification are similar between moco-LGE and bh-LGE when bh-LGE can be acquired well, but bh-LGE quality deteriorates with patient vulnerability. Acquisition time, image quality, diagnostic confidence, and the number of successfully scanned patients are superior with moco-LGE, which extends LGE-based risk stratification to include patients with vulnerability confirmed by outcomes. Moco-LGE may be suitable for routine clinical use.

Which patients with chronic heart failure should be referred for CRT-D implantation? Practical implications of current clinical research

Over the last decade, cardiac resynchronization therapy (CRT) has emerged as an important treatment modality in patients with heart failure. Primary prevention of mortality with implantable cardioverter-defibrillator (ICD) in patients with ischemic and nonischemic cardiomyopathy and left ventricular dysfunction (ejection fraction [EF] < or =35%) has become the standard of care. A growing number of patients with indications for ICD are also eligible for CRT, receiving resynchronization pacing-defibrillator devices (CRT-D). Randomized clinical trials have provided evidence that cardiac resynchronization therapy is beneficial in heart failure patients and contributes to a significant decrease in heart failure progression on top of administering optimal pharmacological therapy. Currently approved indications for CRT-D include utilizing this treatment modality in heart failure patients with New York Heart Association (NYHA) class III or IV, EF < or =35%, and QRS > or =120 ms. New data from MADIT-CRT (Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy) document that patients with less advanced heart failure (ischemic cardiomyopathy in NYHA class I or II and nonischemic cardiomyopathy class II), EF < or =30%, and QRS > or =130 ms also benefit from CRT. These findings indicate that a more proactive approach should be considered regarding the management of heart failure patients with less advanced disease to decrease progression of heart failure with CRT-D therapy.

Comparison of acute electrocardiographic presentation in patients with diastolic vs systolic heart failure

There are limited data comparing admission electrocardiograms (ECGs) in patients with acute diastolic (DHF) vs systolic heart failure (SHF) and their ability to predict cardiac events (CEs). Admission ECGs were evaluated in 241 acute heart failure patients (88 DHF; 153 SHF). DHF was defined as left ventricular ejection fraction >45%. End points consisted of rehospitalization for CEs or death during a 30-day follow-up. DHF patients had more atrial fibrillation (AF) while SHF patients had faster heart rates and longer QRS and QTc duration. There were 68 CEs: 26 (30%) in DHF and 42 (27%) in SHF patients ( P=.728). Multivariate logistic regression analysis revealed that in DHF patients, CEs were associated with nonischemic heart failure, blood urea nitrogen >28 mg/dL, and AF. In the SHF group, CEs were associated with AF. Admission ECG differs between acute DHF and SHF patients. CE rates are similar in both groups; AF is the only ECG parameter predictive of CEs.

Eculizumab: A novel therapy for paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare disease caused by a somatic mutation of the PIGA gene, which results in the absence of the glycosylphosphatidylinositol-linked proteins necessary to protect cells from complement-mediated lysis. The primary clinical manifestations of PNH include intravascular hemolytic anemia, thrombosis in vessels, and bone marrow failure, which can cause pancytopenia. Treatment of PNH has been largely symptomatic until the development of eculizumab, a monoclonal antibody to the C5 complement protein. Data from a randomized, double-blind, placebo-controlled clinical study of patients with PNH demonstrated that over a 26-week period, half of the participants receiving eculizumab experienced less hemolysis as well as stabilization of hemoglobin concentrations, and required fewer blood transfusions as compared to the placebo group. Eculizumab is well tolerated, although due to its blockade of the membrane attack complex there is an increased risk of meningococcal infection. Thus, all patients must receive meningococcal vaccination prior to starting eculizumab. Clinical studies demonstrate that eculizumab may be the first successful specific therapy for the treatment of PNH. (c) 2007 Prous Science. All rights reserved.

Frequency of clinically unsuspected myocardial injury at a children's hospital

BACKGROUND

Ill children are at risk but rarely screened for myocardial injury. The frequency of such injury in ill children is unknown. Elevated levels of plasma cardiac troponin I (cTnI) can detect subclinical myocardial injury.

METHODS

We measured cTnI levels from 283 Children's Hospital, Boston patients (median age 2.10 years, range 0.13-22.4 years) seen in an outpatient or emergency clinic without clinically apparent cardiac disease. We took > or = 0.5 ng/mL as an indication of myocardial injury. We also measured plasma creatine kinase-MB, total creatine kinase, and myoglobin, and performed a chart review.

RESULTS

Fifteen (7.8%) of the 193 acutely ill children and 4 (4.4%) of the 90 well children had an elevated cTnI level (P = .44). Within the acutely ill group, the children with elevated cTnI were younger and had lower mean hemoglobin and hematocrit levels. Cardiac troponin I levels correlated with creatine kinase-MB (r = 0.22; P < .001) but not with creatine kinase or myoglobin. The 4 children with cTnI > 0.89 ng/mL, who also had plasma cardiac troponin T measured, showed cardiac troponin T elevations that were consistent with unstable angina levels in adults. Four children had high-level cTnI elevations (> 2 ng/mL) consistent with acute myocardial infarction levels in adults.

CONCLUSIONS

Elevated cTnI levels occur in children without clinically apparent cardiac disease and can be at adult unstable angina or acute myocardial infarction levels. Prospective studies to determine the clinical significance of these findings and their relationship to the development of cardiomyopathy are warranted.

Cardiovascular disease and toxicities related to HIV infection and its therapies

Cardiovascular manifestations of HIV vary according to disease stage, treatment regimen and geographical location. Common cardiac complications of HIV disease in patients off highly active antiretroviral therapy (HAART) include dilated cardiomyopathy, myocarditis, pericardial effusion, endocarditis, pulmonary hypertension and non-antiretroviral drug-related cardiotoxicity. However, with the introduction of HAART that has substantially modified the course of HIV disease by lengthening survival, additional cardiovascular consequences are a result of the metabolic syndrome with a propensity toward hyperlipidaemia and atherosclerotic heart disease. Because most of the world's HIV-infected patients have not been treated with HAART, the principal HIV-associated cardiovascular manifestations of patients off HAART are reviewed and new knowledge about the prevalence, pathogenesis and treatment in the HAART era are emphasised in this review. Exercise, a nonpharmacological approach to treating HAART-associated metabolic syndrome, is also discussed.

Dronedarone: A new antiarrhythmic agent

Dronedarone (SR 33589; N,N-dibutyl-3-[4-([2-butyl-5-methylsulphonamido] benzofuran-3-yl-carbonyl) phenoxy]propylamine) is a new synthetic noniodinated derivative of amiodarone that is currently undergoing phase III clinical trials. It demonstrates electrophysiologic patterns similar to amiodarone and shows equivalent efficacy in preventing or converting various ventricular and atrial arrhythmias in laboratory animals. Two phase III trials demonstrated that dronedarone is safe and effective for the maintenance of normal sinus rhythm in patients with atrial fibrillation or atrial flutter. Dronedarone at the dose of 400 mg twice daily was effective in preventing both symptomatic and asymptomatic recurrences of atrial fibrillation or atrial flutter and had a safety profile similar to that of placebo. Further studies are needed to determine the long-term effectiveness and safety of dronedarone in various groups of patients with atrial fibrillation. Other clinical applications of this novel antiarrhythmic drug need to be determined in future clinical trials.

Cardiovascular effects of HAART in infants and children of HIV-infected mothers

Over the past decade, the course of human immunodeficiency virus (HIV) infection has been markedly altered by highly active antiretroviral therapy (HAART). As advances in early diagnosis and aggressive therapy, as well as better supportive care, become available to more HIV-infected patients, survival is being prolonged and more patients are experiencing cardiac abnormalities. Cardiovascular manifestations of pediatric HIV infection have especially proven to be an ongoing challenge to practicing physicians, who face cardiac abnormalities ranging from asymptomatic cardiomyopathy to severe heart failure. Antiretroviral therapy has substantially decreased vertical transmission of HIV; however, studies of adults receiving HAART have found increased peripheral and coronary artery disease. Children exposed to this therapy in utero are thus at an increased risk for toxicity and cardiac abnormalities, regardless of their HIV status. Preliminary studies have reported complications including lactic acidosis and mitochondrial toxicity, as well as cardiomyopathy. Further studies are needed to explore the long-term effects and possible toxicities of prophylactic antiretroviral therapy on infants born to HIV-infected mothers.

Cardiovascular complications in patients with HIV infection

As advances in early diagnosis and aggressive therapy, as well as better supportive care, become available to a larger number of patients with HIV infection, survival is being prolonged, and more patients are experiencing cardiac abnormalities. The most common cardiac manifestations of HIV disease are dilated cardiomyopathy, myocarditis, pericardial effusion, endocarditis, pulmonary hypertension, HIV-associated malignant neoplasms, and drug-related cardiotoxicity. The introduction of highly active antiretroviral therapy (HAART) regimens has substantially modified the course of HIV disease by lengthening survival and improving quality of life of HIV-infected patients. However, early data have raised concerns about HAART being associated with an increase in peripheral and coronary arterial disease. This review discusses the principal HIV-associated cardiovascular manifestations and emphasizes new knowledge about their prevalence, pathogenesis, and treatment.

The artificial heart-- past, present, and future

Patients with advanced congestive heart failure have a very high 5-year mortality despite medical treatment. In such patients, heart transplantation is the treatment of choice. The number of patients awaiting transplantation is several-fold higher than the number of procedures performed. Heart transplantation therapy has numerous limitations and is associated with serious complications. The left ventricular assist device is a step towards this goal. It can be attached to the weakened left ventricle to temporarily increase blood flow to the body. The use of left ventricular assist devices helps the failing heart to recover and extends the duration over which a patient's heart can wait for a replacement donor heart. This therapy is in use for only up to a few months. The total artificial heart, Jarvik-7, first implanted in 1982, did not succeed due to a poor quality of a patient's life and numerous complications leading to death. Recently, a successful implantation of the AbioCor (Abiomed), the first fully implantable replacement heart, was accomplished. The AbioCor's internal battery system eliminates the need for the patient to be permanently immobilized through tubes or wires connected to an external power source. Innovative transcutaneous energy transmission permits the recharging of internal batteries. The total artificial heart will require adapting it to different human body sizes as well as further improving its technical features. The total artificial heart is a remedy of the future coming to fruition right now, giving a chance to numerous heart failure patients by extending and improving their lives.

Sexually dimorphic alterations of brain cortical dominance in rats prenatally exposed to TCDD

Sexually dimorphic patterns of cortical lateralization are documented extensively in both human and animal brains. Male rats tend to exhibit pronounced right hemisphere dominance compared with females, whereas females typically exhibit more diffuse lateralization patterns and greater left hemisphere bias compared with males. Prenatal TCDD (2,3,7,8 tetrachlorodibenzo-p-dioxin) exposure produces demasculinization of male offspring sexual behavior. In previous studies, we showed a reversal of cortical dominance in rats after prenatal TCDD exposure on gestational day 18 (GD 18). The current study aimed to determine the nature of changes observed in rats exposed to TCDD on GD 8. In addition, locomotor activity was measured in male and female offspring on postnatal day (PND) 30, 60 and 90. Pregnant females were given, via gavage, a single dose of 0, 20, 60 or 180 ng kg(-1) TCDD on GD 8. Cortical depth measurements were taken in selected brain regions in offspring 3 months old that had been exposed to the 180 ng kg(-1) dose. Areas 2, 3, 17, 18a and 39 at bregmas -1.8, -3.8 and -5.8 were analyzed by quantifying digitized, enhanced images produced by a photomicroscope fitted with a special color camera. In both male and female offspring, cortical thicknesses in control brains exceeded those of exposed brains. In several brain areas of male offspring exposed to TCDD, right hemispheric dominance reversed to left hemispheric dominance. Female offspring brains showed a contrary move towards right hemisphere dominance. Motor activity in juvenile and mature animals did not differ among dose groups. These data demonstrate that prenatal exposure to TCDD reduces cortical thickness and alters the normal pattern of cortical asymmetry, a finding consistent with the sexually dimorphic behavioral effects induced by this agent.