Patients With Hypertrophic Cardiomyopathy and Normal Genetic Investigations Have Few Affected Relatives

BACKGROUND

Current guidelines recommend that relatives of index patients with hypertrophic cardiomyopathy (HCM) are offered clinical investigations to identify individuals at risk of adverse disease complications and sudden cardiac death. However, the value of family screening in relatives of index patients with a normal genetic investigation of recognized HCM genes is largely unknown.

OBJECTIVES

The purpose of this study was to perform family screening among relatives of HCM index patients with a normal genetic investigation to establish the frequency of familial disease and the clinical characteristics of affected individuals.

METHODS

Clinical and genetic investigations were performed in consecutive and unrelated HCM index patients. Relatives of index patients who did not carry pathogenic/likely pathogenic variants in recognized HCM genes were invited for clinical investigations.

RESULTS

In total, 60% (270 of 453) of HCM index patients had a normal genetic investigation. A total of 80% of their relatives (751 of 938, median age 44 years) participated in the study. Of these, 5% (34 of 751) were diagnosed with HCM at baseline, whereas 0.3% (2 of 717 [751-34]) developed the condition during 5 years of follow-up. Their median age at diagnosis was 57 years (IQR: 51-70 years). Two-thirds (22 of 36) were diagnosed following family screening, whereas one-third (14 of 36) had been diagnosed previously because of cardiac symptoms, a murmur, or an abnormal electrocardiogram. None of the affected relatives experienced adverse disease complications. The risk of SCD was low.

CONCLUSIONS

Systematic family screening of index patients with HCM and normal genetic investigations was associated with a low frequency of affected relatives who appeared to have a favorable prognosis.

Risks of Ventricular Arrhythmia and Heart Failure in Carriers of RBM20 Variants

BACKGROUND

Variants in RBM20 are reported in 2% to 6% of familial cases of dilated cardiomyopathy and may be associated with fatal ventricular arrhythmia and rapid heart failure progression. We sought to determine the risk of adverse events in RBM20 variant carriers and the impact of sex on outcomes.

METHODS

Consecutive probands and relatives carrying RBM20 variants were retrospectively recruited from 12 cardiomyopathy units. The primary end point was a composite of malignant ventricular arrhythmia (MVA) and end-stage heart failure (ESHF). MVA and ESHF end points were also analyzed separately and men and women compared. Left ventricular ejection fraction (LVEF) contemporary to MVA was examined. RBM20 variant carriers with left ventricular systolic dysfunction (RBM20LVSD) were compared with variant-elusive patients with idiopathic left ventricular systolic dysfunction.

RESULTS

Longitudinal follow-up data were available for 143 RBM20 variant carriers (71 men; median age, 35.5 years); 7 of 143 had an MVA event at baseline. Thirty of 136 without baseline MVA (22.0%) reached the primary end point, and 16 of 136 (11.8%) had new MVA with no significant difference between men and women (log-rank P=0.07 and P=0.98, respectively). Twenty of 143 (14.0%) developed ESHF (17 men and 3 women; log-rank P<0.001). Four of 10 variant carriers with available LVEF contemporary to MVA had an LVEF >35%. At 5 years, 15 of 67 (22.4%) RBM20LVSD versus 7 of 197 (3.6%) patients with idiopathic left ventricular systolic dysfunction had reached the primary end point (log-rank P<0.001). RBM20 variant carriage conferred a 6.0-fold increase in risk of the primary end point.

CONCLUSIONS

RBM20 variants are associated with a high risk of MVA and ESHF compared with idiopathic left ventricular systolic dysfunction. The risk of MVA in male and female RBM20 variant carriers is similar, but male sex is strongly associated with ESHF.

Metoprolol Improves Left Ventricular Longitudinal Strain at Rest and during Exercise in Obstructive Hypertrophic Cardiomyopathy

BACKGROUND

Patients with obstructive hypertrophic cardiomyopathy (HCM) often experience symptoms of heart failure upon exertion despite having normal left ventricular (LV) ejection fractions. Longitudinal strain (LS) may be a more sensitive marker of systolic dysfunction in patients with LV hypertrophy. The aims of this study were to characterize LV segmental LS and global LS (GLS) at rest and during exercise and to assess if first-line treatment with β-blockers improves LV systolic performance.

METHODS

Twenty-nine patients with obstructive HCM and New York Heart Association functional class ≥ II symptoms were enrolled in a double-blind, placebo-controlled, randomized crossover trial. Patients received metoprolol 150 mg or placebo for two consecutive 2-week periods in random order. Echocardiographic assessment with speckle-tracking-derived LS was performed at rest and during peak exercise at the end of each treatment period.

RESULTS

During placebo treatment, resting values of segmental LS showed an apical-basal difference of -10.3% (95% CI, -12.7% to -7.8%; P < .0001), with a severely abnormal value of the basal segment of -9.3 ± 4.2%. Treatment with metoprolol was associated with more negative LS values of the apical segment (-2.8%; 95% CI, -4.2% to -1.3%; P < .001) and the mid segment (-1.1%; 95% CI, -2.0% to -0.3%; P = .007). During peak exercise there was a deterioration in LV GLS, but treatment with metoprolol was associated with more negative peak exercise LV GLS (-1.3 %; 95% CI, -2.6% to -0.1%; P = .03).

CONCLUSIONS

Systolic performance assessed by LV GLS showed impaired values at rest and during exercise, with severely depressed values of the basal and mid segments. Treatment with metoprolol improved LV GLS upon exercise, indicating a beneficial effect of β-blocker treatment on LV systolic function.

Metoprolol improves left ventricular longitudinal function at rest and during exercise in obstructive hypertrophic cardiomyopathy

Background

Hypertrophic cardiomyopathy (HCM) patients with outflow obstruction often experience symptoms of heart failure upon exertion. We aimed to characterize left ventricular (LV) systolic function by segmental and global longitudinal strain echocardiography, and to investigate changes in relation to exercise, and the effect of standard treatment with beta-blockers.

Method

Twenty-nine patients with obstructive HCM and New York Heart Association (NYHA) class ≥ II symptoms were enrolled in a double-blind, placebo-controlled, randomized crossover trial. Patients received metoprolol 150 mg or placebo for two consecutive two-week periods in random order. Echocardiographic assessment with speckle-tracking derived longitudinal strain (LS) was performed at rest and during peak exercise at the end of each treatment period. Segmental LS was calculated as the mean of the six apical, mid, and basal segments.

Results

During placebo treatment resting values of segmental LS showed an apical-basal difference of −10.3% (95% confidence interval (CI): −12.7 to −7.8; p&lt;0.0001), with severely depressed values of the basal segment −9.3 (4.2) %. Treatment with metoprolol improved LS of the apical segment (−2.8%; 95% CI: −4.2 to −1.3; p&lt;0.001) and mid segment (−1.1%; 95% CI: −2.0 to −0.3; p=0.007). The segmental improvement with metoprolol treatment was reflected in an increase in resting global LS (LV GLS) (−1.4%; 95% CI: −2.3 to −0.6; p&lt;0.001). Peak exercise was associated with a reduction in LV GLS, yet the improvement in LV GLS during metoprolol was consistent upon exercise (−1.3%; 95% CI: −2.6 to −0.1; p=0.03).

Conclusion

Segmental LS of the LV in obstructive HCM showed an abnormal apical-basal difference. Exercise was associated with a reduction in LV GLS, illustrating an impaired myocardial functional reserve capacity. Metoprolol significantly improved LS of the apical and mid segments of the LV at rest and LV GLS during exercise.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Novo nordic foundation

Driving restrictions following defibrillator implantation significantly affect recipients' ability to maintain employment

Background

Following defibrillator implantation or in case of ICD therapy, ICD recipients are subject to temporary driving restrictions for private driving. Moreover, the current European recommendations permanently ban professional driving which can significantly alter the recipients' daily life and ability to maintain employment.

Aim and methods

To investigate Danish ICD recipients' perspective on driving restrictions following ICD implantation we distributed a questionnaire to all living ICD patients with a first-time implantation between 2013 and 2016 (n=3913). We linked questionnaire responses with relevant nationwide Danish registers.

Results

Among the 2741 ICD recipients who responded to the questionnaire (response rate 71%, 47% primary prevention, 83% male, median age 67 years), 2513 (92%) held a valid private driver's license at time of implantation and 175 (7%) were actively using a professional driver's license. Almost all (n=2344, 94%) had resumed driving following device implantation. Among those with a driving ban of at least 1 month following either ICD implantation or ICD therapy (n=911), 26% stated the restrictions had severely impeded their daily life, significantly more in the professional drivers group compared with the private drivers (32% vs 24%, p=0.01). Including only patients working prior to implantation (n=465), 27% stated they were very limited and 20% somewhat limited in maintaining employment following implantation due to the driving restrictions. Likewise, 23% were very limited and 19% somewhat limited in getting to their job. Among the active professional drivers (n=175), 58 (33%) stated they had lost their job as a direct consequence of the post-implantation driving restrictions.

Conclusion

Every fourth Danish ICD recipient is severely limited in their daily life due to the driving restrictions. Both professional and private drivers are significantly affected with regards to maintaining employment following implantation, which should be a key focus in rehabilitation programs.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): The Danish Heart Foundation and Arvid Nilssons Fond

Informing patients about potential adverse drug reactions after percutaneous coronary intervention reduces the occurrence of self-reported adverse drug reactions

Background

Healthcare providers are commonly reluctant to inform patients about potential adverse drug reactions (ADRs) from prescribed therapy to avoid increasing the incidence of ADRs through the nocebo effect. However, patients need information on all aspects of prescribed therapy to facilitate informed decision-making and take ownership of their care.

Purpose

To describe wether patients received information about potential ADRs from prescribed therapy before hospital discharge after percutaneous coronary intervention (PCI). Furthermore, to determine whether receiving information about ADRs is associated with incidence of self-reported ADRs.

Methods

CONCARDPCI is a prospective multicentre cohort study including 3417 patients after PCI. The study was conducted between June 2017 and May 2020 at seven large referral PCI centres in Norway and Denmark. Clinical data were collected from patients' medical records. Socio-demographic characteristics were obtained by self-report during index hospitalization after PCI. Two questions from the Heart Continuity of Care Questionnaire were used to determine if information about potential ADRs was received before hospital discharge. De novo created questions were used to determine if patients reported ADRs from prescribed therapy. Questionnaires were distributed two (T1), six (T2), and twelve months (T3) after hospital discharge to assess the incidence of self-reported ADRs in a longitudinal perspective. Logistic regression was utilised to scrutinize the aims, reported as odds ratios (ORs) with 95% confidence intervals (CIs).

Results

Patients were predominantly men (78%), with a mean age of 66 years (SD 11, range 20–96 years), and married or living with a partner (75%). Stable coronary artery disease was the most frequent cause of admission for PCI (30%). Before hospital discharge, 59% were informed of potential ADRs from prescribed therapy and 50% were informed what to do if ADRs occurred. The incidence of self-reported ADRs were significantly lower for those who were informed of potential ADRs compared to those who were not informed at T1 (OR 0.54, CI: 0.45–0.65, p&lt;0.001), T2 (OR 0.56, CI: 0.46–0.70, p&lt;0.001) and T3 (OR 0.51, CI: 0.42–0.67, p&lt;0.001) (Figure 1). After controlling for socio-demographic and clinical variables, the incidence of self-reported ADRs were similar at T1 (OR 0.58, CI: 0.47–0.71, p&lt;0.001), T2 (OR 0.56, CI: 0.46–0.70, p&lt;0.001) and T3 (OR 0.53, CI: 0.42–0.66, p&lt;0.001). Those less likely to receive information about ADRs were living alone (OR 0.75, CI: 0.59–0.97; p=0.029), women (OR 0.58, CI: 0.45–0.75, p&lt;0.001) and those with three or more comorbidities (OR 0.68, CI: 0.47–0.98, p=0.029) compared to their counterparts.

Conclusion

Our study showed that informing patients about potential ADRs after PCI reduces the occurrence of self-reported ADRs. Information about potential ADRs should be provided regardless of cohabitation status, sex and comorbidities.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Western Norway Health Authority

Influence of sex on cardiovascular outcomes in RBM20 variant carriers

Background

Variants in the RBM20 gene cause dilated cardiomyopathy and may be associated with a poor prognosis.

Objectives

To determine disease penetrance, the risk of adverse events and the influence of sex on outcomes in RBM20 variant carriers.

Methods

Consecutive probands and relatives carrying pathogenic or likely pathogenic RBM20 variants were retrospectively recruited from 12 cardiomyopathy units. The primary endpoint was a composite of malignant ventricular arrhythmia (MVA) and end-stage heart failure (ESHF). MVA and ESHF endpoints were also analysed separately and males and females compared.

Results

Longitudinal follow-up data were available for 163 RBM20 variant carriers (82 male, median age 36.5 years, median follow-up 77.6 months). 10/163 had an MVA event at baseline. 30/153 without baseline MVA (19.6%) reached the primary endpoint with a trend towards worse outcomes in males (p=0.08). 16/153 (10.5%) had new MVA with no difference between males and females (p=0.92). 20/163 (12.2%) developed ESHF (17 males and 3 females; p&lt;0.001).

By the end of follow-up, 114 patients (70%) had either left ventricular systolic dysfunction (LVSD) or had experienced MVA. 22 patients received a first diagnosis of LVSD during follow-up. Disease penetrance in individuals over 40 years of age was 78.5% by last evaluation.

Eleven patients that reached the MVA endpoint had a left ventricular ejection fraction (LVEF) available within 6 months of the event. Median [IQR] contemporary LVEF was 30% [23.75, 40%]. 5/11 patients had a contemporary LVEF &gt;35%. 1/11 had a contemporary LVEF &gt;45% (a female, 1st degree relative presenting with sustained ventricular tachycardia and an LVEF of 65%).

Conclusions

RBM20 variants are highly penetrant. The risk of MVA in male and female RBM20 variant carriers is similar but male sex is strongly associated with ESHF. MVA events occur in patients with LVEF &gt;35%.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation Clinical Research Training Fellowship

Psychometric evaluation of the danish version of the electronic health literacy scale (eHEALS) in patients treated with percutaneous coronary intervention (PCI): A cross-sectional validation study

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction

As many use the internet as a major source of health information, eHealth literacy has emerged as a potential concept for digital health care consumption. Therefore, healthcare professionals need to consider the eHealth literacy of patients when delivering health information to cardiac patients.

Purpose

The aim of this study was to translate and evaluate the psychometric properties of the Danish version of the Electronic Health Literacy Scale (eHEALS) in a population of Danish PCI treated patients.

Methods

The eHEALS was translated into Danish from the original English version, including forward translation, synthesis, backward translation and expert group consensus. The questionnaire was applied to a group of Danish PCI treated patients to be answered during hospital stay. Psychometric properties were assessed including internal consistency by Cronbach α, and confirmatory factor analysis (CFA) with a priori specified 1-, 2- and 3-factor models were performed to explore construct validity. Socio-demographic and patient-reported outcomes including health literacy, health-related internet use, and health status were collected to examine correlations with eHEALS scores.

Results

A total of 1473 PCI treated patients were included in the analysis. The mean age was 66 years (SD 10.70) and more patients were males (n=1130, 78%). The mean value for the eHEALS score was 28.87 (SD 6.34), and the Cronbach α 0.94. The CFA indicated a good fit for three out of four of the goodness-of -fit indices. A mean difference on the eHEALS score between patients with the highest and lowest educational level was found to be 4.64 (95%CI, 2.43-6.85), p&lt;0.0001.

Strong correlations were observed between eHEALS scores and "ability to find good information"(r=0.636), "Understanding health information well enough to know what to do" (r=0.505), ‘patients’ perceived usefulness’ (r= 0.650) and ‘importance of using the internet’ (r=0.621). Moderate correlations were observed to ‘having used the internet to find information about health’ (r=0.464), and "Appraisal of health information" (r=0.462), and weak correlations to self-rated physical health (r=0.119), self-rated mental health (r=0.110), and social support (r=0.207).

Conclusion

The psychometric evaluation indicates that the Danish version of the eHEALS questionnaire is a valid instrument to measure eHealth literacy in patients treated with PCI, suggesting a multidimensional construct.

Clinical Features and Natural History of Preadolescent Nonsyndromic Hypertrophic Cardiomyopathy

BACKGROUND

Up to one-half of childhood sarcomeric hypertrophic cardiomyopathy (HCM) presents before the age of 12 years, but this patient group has not been systematically characterized.

OBJECTIVES

The aim of this study was to describe the clinical presentation and natural history of patients presenting with nonsyndromic HCM before the age of 12 years.

METHODS

Data from the International Paediatric Hypertrophic Cardiomyopathy Consortium on 639 children diagnosed with HCM younger than 12 years were collected and compared with those from 568 children diagnosed between 12 and 16 years.

RESULTS

At baseline, 339 patients (53.6%) had family histories of HCM, 132 (20.9%) had heart failure symptoms, and 250 (39.2%) were prescribed cardiac medications. The median maximal left ventricular wall thickness z-score was 8.7 (IQR: 5.3-14.4), and 145 patients (27.2%) had left ventricular outflow tract obstruction. Over a median follow-up period of 5.6 years (IQR: 2.3-10.0 years), 42 patients (6.6%) died, 21 (3.3%) underwent cardiac transplantation, and 69 (10.8%) had life-threatening arrhythmic events. Compared with those presenting after 12 years, a higher proportion of younger patients underwent myectomy (10.5% vs 7.2%; P = 0.045), but fewer received primary prevention implantable cardioverter-defibrillators (18.9% vs 30.1%; P = 0.041). The incidence of mortality or life-threatening arrhythmic events did not differ, but events occurred at a younger age.

CONCLUSIONS

Early-onset childhood HCM is associated with a comparable symptom burden and cardiac phenotype as in patients presenting later in childhood. Long-term outcomes including mortality did not differ by age of presentation, but patients presenting at younger than 12 years experienced adverse events at younger ages.

Relationship Between Maximal Left Ventricular Wall Thickness and Sudden Cardiac Death in Childhood Onset Hypertrophic Cardiomyopathy

BACKGROUND

Maximal left ventricular wall thickness (MLVWT) is a risk factor for sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM). In adults, the severity of left ventricular hypertrophy has a nonlinear relationship with SCD, but it is not known whether the same complex relationship is seen in childhood. The aim of this study was to describe the relationship between left ventricular hypertrophy and SCD risk in a large international pediatric HCM cohort.

METHODS

The study cohort comprised 1075 children (mean age, 10.2 years [±4.4]) diagnosed with HCM (1-16 years) from the International Paediatric Hypertrophic Cardiomyopathy Consortium. Anonymized, noninvasive clinical data were collected from baseline evaluation and follow-up, and 5-year estimated SCD risk was calculated (HCM Risk-Kids).

RESULTS

MLVWT Z score was <10 in 598 (58.1%), ≥10 to <20 in 334 (31.1%), and ≥20 in 143 (13.3%). Higher MLVWT Z scores were associated with heart failure symptoms, unexplained syncope, left ventricular outflow tract obstruction, left atrial dilatation, and nonsustained ventricular tachycardia. One hundred twenty-two patients (71.3%) with MLVWT Z score ≥20 had coexisting risk factors for SCD. Over a median follow-up of 4.9 years (interquartile range, 2.3-9.3), 115 (10.7%) had an SCD event. Freedom from SCD event at 5 years for those with MLVWT Z scores <10, ≥10 to <20, and ≥20 was 95.6%, 87.4%, and 86.0, respectively. The estimated SCD risk at 5 years had a nonlinear, inverted U-shaped relationship with MLVWT Z score, peaking at Z score +23. The presence of coexisting risk factors had a summative effect on risk.

CONCLUSIONS

In children with HCM, an inverted U-shaped relationship exists between left ventricular hypertrophy and estimated SCD risk. The presence of additional risk factors has a summative effect on risk. While MLVWT is important for risk stratification, it should not be used either as a binary variable or in isolation to guide implantable cardioverter defibrillator implantation decisions in children with HCM.

Effects of Metoprolol on Exercise Hemodynamics in Patients With Obstructive Hypertrophic Cardiomyopathy

BACKGROUND

The relationship between exercise hemodynamics, loading conditions, and medical treatment in patients with obstructive hypertrophic cardiomyopathy (HCM) is incompletely understood.

OBJECTIVES

This study aimed to investigate the effect of metoprolol on invasive hemodynamic parameters at rest and during exercise in patients with obstructive HCM.

METHODS

This randomized, double-blind, placebo-controlled crossover trial enrolled 28 patients with obstructive HCM and New York Heart Association functional class ≥II. Patients were randomized to initiate either metoprolol 150 mg or placebo for 2 consecutive 2-week periods. Right-heart catheterization and echocardiography were performed at rest and during exercise at the end of each treatment period. The primary outcome was the difference in pulmonary capillary wedge pressure (ΔPCWP) between peak exercise and rest.

RESULTS

No treatment effect on ΔPCWP was observed between metoprolol and placebo treatment (21 ± 9 mm Hg vs 23 ± 9 mm Hg; P = 0.12). At rest, metoprolol lowered heart rate (P < 0.0001), left ventricular outflow tract (LVOT) gradient (P = 0.01), and increased left ventricular end-diastolic volume (P = 0.02) and stroke volume (SV) (+6.4; 95% CI: 0.02-17.7; P = 0.049). During peak exercise, metoprolol was associated with a lower heart rate (P < 0.0001), a lower LVOT gradient (P = 0.0005), lesser degree of mitral regurgitation (P = 0.004), and increased SV (+9 mL; 95% CI: 2-15 mL; P = 0.008).

CONCLUSIONS

In patients with obstructive HCM, exercise was associated with an abnormal rise in PCWP, which was unaffected by metoprolol. However, metoprolol increased SV at rest and peak exercise following changes in end-diastolic volume, LVOT gradient, and degree of mitral regurgitation. (The Effect of Metoprolol in Patients With Hypertrophic Obstructive Cardiomyopathy [TEMPO]; NCT03532802).

Randomized Trial of Metoprolol in Patients With Obstructive Hypertrophic Cardiomyopathy

BACKGROUND

The use of β-adrenergic receptor blocking agents in symptomatic patients with obstructive hypertrophic cardiomyopathy (HCM) rests on clinical experience and observational cohort studies.

OBJECTIVES

This study aimed to investigate the effects of metoprolol on left ventricular outflow tract (LVOT) obstruction, symptoms, and exercise capacity in patients with obstructive HCM.

METHODS

This double-blind, placebo-controlled, randomized crossover trial enrolled 29 patients with obstructive HCM and New York Heart Association (NYHA) functional class II or higher symptoms from May 2018 to September 2020. Patients received metoprolol or placebo for 2 consecutive 2-week periods in random order. The effect parameters were LVOT gradients, NYHA functional class, Canadian Cardiovascular Society (CCS) angina class, Kansas City Cardiomyopathy Questionnaire Overall Summary Score (KCCQ-OSS), and cardiopulmonary exercise testing.

RESULTS

Compared with placebo, the LVOT gradient during metoprolol was lower at rest (25 mm Hg [interquartile range (IQR): 15-58 mm Hg] vs 72 mm Hg [IQR: 28-87 mm Hg]; P = 0.007), at peak exercise (28 mm Hg [IQR: 18-40 mm Hg] vs 62 mm Hg [IQR: 31-113 mm Hg]; P < 0.001), and postexercise (45 mm Hg [IQR: 24-100 mm Hg] vs 115 mm Hg [IQR: 55-171 mm Hg]; P < 0.0001). During metoprolol treatment, 14% of patients were in NYHA functional class III or higher compared with 38% of patients receiving placebo (P < 0.01). Similarly, no patients were in CCS class III or higher during metoprolol treatment compared with 10% during placebo treatment (P < 0.01). These findings were confirmed by higher KCCQ-OSS during metoprolol treatment (76.2 ± 16.2 vs 73.8 ± 19.5; P = 0.039). Measures of exercise capacity, peak oxygen consumption, and N-terminal pro-B-type natriuretic peptide did not differ between the study arms.

CONCLUSIONS

Compared with placebo, metoprolol reduced LVOT obstruction at rest and during exercise, provided symptom relief, and improved quality of life in patients with obstructive HCM. Maximum exercise capacity remained unchanged. (The Effect of Metoprolol in Patients with Hypertrophic Obstructive Cardiomyopathy [TEMPO]; NCT03532802).

Alpha-protein kinase 3 (ALPK3) truncating variants cause an autosomal dominant form of hypertrophic cardiomyopathy

Background

More than half of hypertrophic cardiomyopathy (HCM) remains genetically unsolved. ALPK3 truncating variants (ALPK3tv) have been described as a cause of autosomal recessive cardiomyopathy in a small number of paediatric cases, but the pathogenicity in heterozygosity as a possible cause of autosomal dominant HCM is unknown.

Aims

To determine the frequency of heterozygous ALPK3tv in patients with HCM and to confirm their pathogenicity by means of burden testing in independent cohorts, family co-segregation studies, and functional analysis of an allelic series of ALPK3tv using human embryonic stem cell-cardiomyocytes (hESC-CM). Phenotype was compared with a cohort of 1679 genotyped HCM patients.

Methods and results

In a discovery cohort of 770 index patients with HCM, 12 (1.56%) were heterozygous for ALPK3tv, odds ratio (OR) 16.01 (95% confidence interval (95% CI): 7.89 to 29.74, p&lt;8.36e-11), compared to the Genome Aggregation Database (gnomAD) population. In a validation cohort of 2047 HCM probands, 32 (1.56%) carried heterozygous ALPK3tv, OR 16.17 (95% CI: 10.31 to 24.87; p&lt;2.2e-16, compared to gnomAD). Combined logarithm of odds score in 7 families with ALPK3tv was 2.99. In comparison with a large cohort of genotyped HCM patients, the phenotype of 51 HCM patients with ALPK3tv (probands and relatives) was characterised by a higher prevalence of apical/concentric patterns of hypertrophy (60%) compared to both sarcomere-positives or negatives (p&lt;0.001 overall), with the age at diagnosis (56±16ys) and maximum wall thickness (18±4mm) similar to sarcomere-negatives and LV systolic impairment at baseline (6%) and non-sustained ventricular tachycardia (31%) similar to sarcomere-positives. Short PR (10%, p=0.009 overall) and extensive fibrosis&gt;15% of LV segments (49%) were distinctive features. During follow-up (5.3±5.7 years), 4 (9%) patients died of heart failure or had cardiac transplantation (p=0.012 vs sarcomere-negatives and p=0.425 vs sarcomere-positives). Analysis of hESC-CM showed that ALPK3 heterozygotes had phenotypic characteristics of HCM, including increased contractile force and delayed membrane repolarization.

Conclusions

Heterozygous ALPK3tv are pathogenic and segregate with a characteristic HCM phenotype.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): MRC UK, UCLH BRC

Clinical effects of metoprolol in obstructive hypertrophic cardiomyopathy (TEMPO). A randomized, double-blinded, placebo-controlled crossover trial

Background

Treatment with beta blockers (BB) has been used for symptomatic relief in patients with obstructive hypertrophic cardiomyopathy (HCM) for decades. Even so, the guideline recommendation for the use of BB rests on expert opinions and observational cohort studies. Providing comprehensive high-quality data on the effects of BB in obstructive HCM is essential, especially in the context of newly developed pharmacological treatment strategies specifically targeting this disease (1).

Purpose

The study aimed to investigate the effects of metoprolol on left ventricular outflow tract (LVOT) obstruction, symptoms, and exercise capacity in patients with obstructive HCM.

Methods

This double-blinded, placebo-controlled, randomized crossover trial enrolled 30 patients with obstructive HCM and New York Heart Association (NYHA) class ≥ II symptoms from 1 May 2018 to 1 September 2020. Patients received metoprolol or placebo for two consecutive two-week periods in random order. The effect parameters were LVOT gradients, NYHA class, Canadian Cardiovascular Society (CCS) grading angina class, Kansas City Cardiomyopathy Questionnaire Overall Summary Score (KCCQ-OSS), and cardiopulmonary exercise testing.

Results

Compared with placebo, the LVOT gradient during metoprolol was lower at rest (25 [15–58] mmHg versus 72 [28–87] mmHg; p=0.007), at peak exercise (28 [18–40] mmHg versus 62 [31–113] mmHg; p&lt;0.001), and post-exercise (45 [24–100] mmHg versus 115 [55–171] mmHg; p&lt;0.0001) (figure 1). During metoprolol treatment, 14% of patients were in NYHA class III compared with 38% on placebo (p&lt;0.01). Likewise, no patients were in CCS class ≥ III during metoprolol compared with 10% during placebo (p&lt;0.01). These findings were confirmed by a higher KCCQ-OSS score during metoprolol (76.2 (16.2) versus 73.8 (19.5), p=0.039) (figure 2). Peak oxygen consumption did not differ between study arms.

Conclusion

Compared with placebo, metoprolol reduced LVOT obstruction at rest and during exercise, provided symptom relief, and improved quality of life in patients with obstructive HCM. However, exercise capacity remained unchanged. Findings from the present study support the guideline recommendations that BB should be the first drug of choice in patients with obstructive HCM who develop symptoms.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Novo nordic foundation, Skibsreder Per Henriksen, R. og hustrus Foundation

Prevalence and clinical outcomes of dystrophin-associated dilated cardiomyopathy without severe skeletal myopathy

AIMS

Dilated cardiomyopathy (DCM) associated with dystrophin gene (DMD) mutations in individuals with mild or absent skeletal myopathy is often indistinguishable from other DCM forms. We sought to describe the phenotype and prognosis of DMD associated DCM in DMD mutation carriers without severe skeletal myopathy.

METHODS AND RESULTS

At 26 European centres, we retrospectively collected clinical characteristics and outcomes of 223 DMD mutation carriers (83% male, 33 ± 15 years). A total of 112 individuals (52%) had DCM at first evaluation [n = 85; left ventricular ejection fraction (LVEF) 34 ± 11.2%] or developed DCM (n = 27; LVEF 41.3 ± 7.5%) after a median follow-up of 96 months (interquartile range 5-311 months). DCM penetrance was 45% in carriers older than 40 years. DCM appeared earlier in males and was independent of the type of mutation, presence of skeletal myopathy, or elevated serum creatine kinase levels. Major adverse cardiac events (MACE) occurred in 22% individuals with DCM, 18% developed end-stage heart failure and 9% sudden cardiac death or equivalent. Skeletal myopathy was not associated with survival free of MACE in patients with DCM. Decreased LVEF and increased left ventricular end-diastolic diameter at baseline were associated with MACE. Individuals without DCM had favourable prognosis without MACE or death during follow-up.

CONCLUSIONS

DMD-associated DCM without severe skeletal myopathy is characterized by incomplete penetrance but high risk of MACE, including progression to end-stage heart failure and ventricular arrhythmias. DCM onset is the major determinant of prognosis with similar survival regardless of the presence of skeletal myopathy.

The role of the electrocardiographic phenotype in risk stratification for sudden cardiac death in childhood hypertrophic cardiomyopathy

AIMS

The 12-lead electrocardiogram (ECG) is routinely performed in children with hypertrophic cardiomyopathy (HCM). An ECG risk score has been suggested as a useful tool for risk stratification, but this has not been independently validated. This aim of this study was to describe the ECG phenotype of childhood HCM in a large, international, multi-centre cohort and investigate its role in risk prediction for arrhythmic events.

METHODS AND RESULTS

Data from 356 childhood HCM patients with a mean age of 10.1 years (±4.5) were collected from a retrospective, multi-centre international cohort. Three hundred and forty-seven (97.5%) patients had ECG abnormalities at baseline, most commonly repolarization abnormalities (n = 277, 77.8%); left ventricular hypertrophy (n = 240, 67.7%); abnormal QRS axis (n = 126, 35.4%); or QT prolongation (n = 131, 36.8%). Over a median follow-up of 3.9 years (interquartile range 2.0-7.7), 25 (7%) had an arrhythmic event, with an overall annual event rate of 1.38 (95% CI 0.93-2.04). No ECG variables were associated with 5-year arrhythmic event on univariable or multivariable analysis. The ECG risk score threshold of >5 had modest discriminatory ability [C-index 0.60 (95% CI 0.484-0.715)], with corresponding negative and positive predictive values of 96.7% and 6.7.

CONCLUSION

In a large, international, multi-centre cohort of childhood HCM, ECG abnormalities were common and varied. No ECG characteristic, either in isolation or combined in the previously described ECG risk score, was associated with 5-year sudden cardiac death risk. This suggests that the role of baseline ECG phenotype in improving risk stratification in childhood HCM is limited.

Clinical and Genetic Investigations of 109 Index Patients With Dilated Cardiomyopathy and 445 of Their Relatives

BACKGROUND

It was the aim to investigate the frequency and genetic basis of dilated cardiomyopathy (DCM) among relatives of index patients with unexplained heart failure at a tertiary referral center.

METHODS

Clinical investigations were performed in 109 DCM index patients and 445 of their relatives. All index patients underwent genetic investigations of 76 disease-associated DCM genes. A family history of DCM occurred in 11% (n=12) while clinical investigations identified familial DCM in a total of 32% (n=35). One-fifth of all relatives (n=95) had DCM of whom 60% (n=57) had symptoms of heart failure at diagnosis, whereas 40% (n=38) were asymptomatic. Symptomatic relatives had a shorter event-free survival than asymptomatic DCM relatives (P<0.001).

RESULTS

Genetic investigations identified 43 pathogenic (n=27) or likely pathogenic (n=16) variants according to the American College of Medical Genetics and Genomics and the Association for Molecular Pathology criteria. Forty-four percent (n=48/109) of index patients carried a pathogenic/likely pathogenic variant of whom 36% (n=27/74) had sporadic DCM, whereas 60% (21/35) were familial cases. Thirteen of the pathogenic/likely pathogenic variants were also present in ≥7 affected individuals and thereby considered to be of sufficient high confidence for use in predictive genetic testing.

CONCLUSIONS

A family history of DCM identified only 34% (n=12/35) of hereditary DCM, whereas systematic clinical screening identified the remaining 66% (n=23) of DCM families. This emphasized the importance of clinical investigations to identify familial DCM. The high number of pathogenic/likely pathogenic variants identified in familial DCM provides a firm basis for offering genetic investigations in affected families. This should also be considered in sporadic cases since adequate family evaluation may not always be possible and the results of the genetic investigations may carry prognostic information with an impact on individual management.

Pathogenic RBM20-Variants Are Associated With a Severe Disease Expression in Male Patients With Dilated Cardiomyopathy

Background As pathogenic variants in the gene for RBM20 appear with a frequency of 6% among Danish patients with dilated cardiomyopathy (DCM), it was the aim to investigate the associated disease expression in affected families. Methods and Results Clinical investigations were routinely performed in DCM index-patients and their relatives. In addition, ≥76 recognized and likely DCM-genes were investigated. DNA-sequence-variants within RBM20 were considered suitable for genetic testing when they fulfilled the criteria of (1) being pathogenic according to the American College of Medical Genetics and Genomics-classification, (2) appeared with an allele frequency of <1:10.000, and (3) segregated with DCM in ≥7 affected individuals. A total of 80 individuals from 15 families carried 5 different pathogenic RBM20-variants considered suitable for genetic testing. The penetrance was 66% (53/80) and age-dependent. Males were both significantly younger and had lower ejection fraction at diagnosis than females (age, 29±11 versus 48±12 years; P<0.01; ejection fraction, 29±13% versus 38±9%; P<0.01). Furthermore, 11 of 31 affected males needed a cardiac transplant while none of 22 affected females required this treatment ( P<0.001). Thirty percent of RBM20-carriers with DCM died suddenly or experienced severe ventricular arrhythmias although no adverse events were identified among healthy RBM20-carriers with a normal cardiac investigation. The event-free survival of male RBM20-carriers was significantly shorter compared with female carriers ( P<0.001). Conclusions The disease expression associated with pathogenic RBM20-variants was severe especially in males. The findings of the current study suggested that close clinical follow-up of RBM20-carriers is important which may ensure early detection of disease development and thereby improve management.

P337Natural history, reversibility and arrhythmias associated with truncating titin variants in dilated cardiomyopathy

Background

Truncating genetic variants in titin (TTNtv) are identified in 15–25% of patients with primary dilated cardiomyopathy (DCM). Previous genotype/phenotype studies have reported conflicting results regarding disease severity and pathologic features associated with TTNtv.

Purpose

To investigate the natural history, reversibility and burden of arrhythmias associated with TTNtv in a Danish cohort with long-term follow-up.

Methods

Patients with DCM, recruited from two Danish tertiary centers, were included based on the presence of a TTNtv in a cardiac expressed titin exon. Data on patients' medical history including symptoms, demography, family history, comorbidities, treatment, ECG features, and echocardiograms were registered. Outcome data including all-cause mortality, need of heart transplantation (HTX) or left ventricular assist device (LVAD), and presence of ventricular and supraventricular arrhythmias were registered. Left ventricular reverse remodeling (LVRR) was defined as an absolute increase in left ventricular ejection fraction (LVEF) ≥10% points or normalization.

Results

A total of 104 patients (71 men, 69%; 72 probands) with definite TTNtv-DCM were included. The mean age at DCM diagnosis was (mean±SD) 45±13 years (43±13 for men; 49±14 for women, p<0.04) and median follow-up was 8.1 years. The mean LVEF was 28±13% at time of diagnosis (26±12% for men; 30±13% for women, p=0.173). During follow-up, 31 patients (30%; 24 men) died or needed HTX/LVAD. Medical therapy was associated with LVRR in 79% of patients 3.6 years after diagnosis. LVRR was maintained long-term in 64% of patients. Women had a better response to medical therapy compared to men (mean LVEF increase 19%; vs 15% in men, p<0.04). Atrial fibrillation/flutter was observed in 40% of patients and ventricular arrhythmias in 23% of patients. Men had an earlier occurrence of both supraventricular and ventricular arrhythmias (p=0.005) with half of the men having experienced an arrhythmia at the age of 54 years.

Freedom from arrhythmias with age

Conclusion

TTNtv leads to a DCM phenotype associated with a marked gender-difference in age at DCM diagnosis and high burden of both supraventricular and ventricular arrhythmias. Importantly, the DCM-TTNtv phenotype was associated with a high degree of reversibility of systolic function following medical therapy.

Development of a Novel Risk Prediction Model for Sudden Cardiac Death in Childhood Hypertrophic Cardiomyopathy (HCM Risk-Kids)

Importance

Sudden cardiac death (SCD) is the most common mode of death in childhood hypertrophic cardiomyopathy (HCM), but there is no validated algorithm to identify those at highest risk.

Objective

To develop and validate an SCD risk prediction model that provides individualized risk estimates.

Design, Setting, and Participants

A prognostic model was developed from a retrospective, multicenter, longitudinal cohort study of 1024 consecutively evaluated patients aged 16 years or younger with HCM. The study was conducted from January 1, 1970, to December 31, 2017.

Exposures

The model was developed using preselected predictor variables (unexplained syncope, maximal left-ventricular wall thickness, left atrial diameter, left-ventricular outflow tract gradient, and nonsustained ventricular tachycardia) identified from the literature and internally validated using bootstrapping.

Main Outcomes and Measures

A composite outcome of SCD or an equivalent event (aborted cardiac arrest, appropriate implantable cardioverter defibrillator therapy, or sustained ventricular tachycardia associated with hemodynamic compromise).

Results

Of the 1024 patients included in the study, 699 were boys (68.3%); mean (interquartile range [IQR]) age was 11 (7-14) years. Over a median follow-up of 5.3 years (IQR, 2.6-8.3; total patient years, 5984), 89 patients (8.7%) died suddenly or had an equivalent event (annual event rate, 1.49; 95% CI, 1.15-1.92). The pediatric model was developed using preselected variables to predict the risk of SCD. The model's ability to predict risk at 5 years was validated; the C statistic was 0.69 (95% CI, 0.66-0.72), and the calibration slope was 0.98 (95% CI, 0.59-1.38). For every 10 implantable cardioverter defibrillators implanted in patients with 6% or more of a 5-year SCD risk, 1 patient may potentially be saved from SCD at 5 years.

Conclusions and Relevance

This new, validated risk stratification model for SCD in childhood HCM may provide individualized estimates of risk at 5 years using readily obtained clinical risk factors. External validation studies are required to demonstrate the accuracy of this model's predictions in diverse patient populations.

The clinical outcome of LMNA missense mutations can be associated with the amount of mutated protein in the nuclear envelope

AIMS

Lamin A/C mutations are generally believed to be associated with a severe prognosis. The aim of this study was to investigate disease expression in three affected families carrying different LMNA missense mutations. Furthermore, the potential molecular disease mechanisms of the mutations were investigated in fibroblasts obtained from mutation carriers.

METHODS AND RESULTS

A LMNA-p.Arg216Cys missense mutation was identified in a large family with 36 mutation carriers. Disease expression was unusual with a late onset and a favourable prognosis. Two smaller families with severe disease expression were shown to carry a LMNA-p.Arg471Cys and LMNA-p.Arg471His mutation, respectively. LMNA gene and protein expression was investigated in eight different mutation carriers by quantitative reverse transcriptase polymerase chain reaction, Western blotting, immunohistochemistry, and protein mass spectrometry. The results showed that all mutation carriers incorporated mutated lamin protein into the nuclear envelope. Interestingly, the ratio of mutated to wild-type protein was only 30:70 in LMNA-p.Arg216Cys carriers with a favourable prognosis while LMNA-p.Arg471Cys and LMNA-p.Arg471His carriers with a more severe outcome expressed significantly more of the mutated protein by a ratio of 50:50.

CONCLUSION

The clinical findings indicated that some LMNA mutations may be associated with a favourable prognosis and a low risk of sudden death. Protein expression studies suggested that a severe outcome was associated with the expression of high amounts of mutated protein. These findings may prove to be helpful in counselling and risk assessment of LMNA families.

Short time window for transmissibility of African swine fever virus from a contaminated environment

Since the introduction of African swine fever virus (ASFV) into the Baltic states and Poland in 2014, the disease has continued to spread within these regions. In 2017, the virus spread further west and the first cases of disease were reported in the Czech Republic and Romania, in wild boar and domestic pigs, respectively. To control further spread, knowledge of different modes of transmission, including indirect transmission via a contaminated environment, is crucial. Up until now, such an indirect mode of transmission has not been demonstrated. In this study, transmission via an environment contaminated with excretions from ASFV-infected pigs was investigated. Following euthanasia of pigs that were infected with an isolate of ASFV from Poland (POL/2015/Podlaskie/Lindholm), healthy pigs were introduced into the pens, in which the ASFV-infected pigs had been housed. Introduction was performed at 1, 3, 5 or 7 days, following euthanasia of the infected pig groups. Pigs, that were introduced into the contaminated environment after 1 day, developed clinical disease within 1 week, and both ASFV DNA and infectious virus were isolated from their blood. However, pigs introduced into the contaminated pens after 3, 5 or 7 days did not develop any signs of ASFV infection and no viral DNA was detected in blood samples obtained from these pigs within the following 3 weeks. Thus, it was shown that exposure of pigs to an environment contaminated with ASFV can result in infection. However, the time window for transmissibility of ASFV seems very limited, and, within our experimental system, there appears to be a rapid decrease in the infectivity of ASFV in the environment.

Characterization of a Novel Chimeric Swine Enteric Coronavirus from Diseased Pigs in Central Eastern Europe in 2016

During a severe outbreak of diarrhoea and vomiting in a pig herd in Central Eastern Europe, faecal samples were tested positive for porcine epidemic diarrhoea virus (PEDV) and negative for transmissible gastroenteritis virus (TGEV) using a commercial RT-qPCR assay that can detect both of these coronaviruses. However, further analyses, using other TGEV- and PEDV-specific RT-qPCR assays, provided results inconsistent with infection by either of these viruses. Sequencing of an amplicon (ca. 1.6 kb), generated by an RT-PCR specific for the PEDV S-gene, indicated a very close similarity (ca. 99% identity) to recently described chimeric viruses termed swine enteric coronaviruses (SeCoVs). These viruses (with an RNA genome of ca. 28 kb) were first identified in Italy in samples from 2009 but have not been detected there since 2012. A closely related virus was detected in archived samples in Germany from 2012, but has not been detected subsequently. Building on the initial sequence data, further amplicons were generated and over 9 kb of sequence corresponding to the 3'-terminus of the new SeCoV genome was determined. Sequence comparisons showed that the three known SeCoVs are ≥98% identical across this region and contain the S-gene and 3a sequences from PEDV within a backbone of TGEV, but the viruses are clearly distinct from each other. It is demonstrated, for the first time, that pigs from within the SeCoV-infected herd seroconverted against PEDV but tested negative in a TGEV-specific ELISA that detects antibodies against the S protein. These results indicate that SeCoV is continuing to circulate in Europe and suggest it can cause a disease that is very similar to PED. Specific detection of the chimeric SeCoVs either requires development of a new diagnostic RT-qPCR assay or the combined use of assays targeting the PEDV S-gene and another part of the TGEV genome.

RBM20 Regulates Circular RNA Production From the Titin Gene

RATIONALE

RNA-binding motif protein 20 (RBM20) is essential for normal splicing of many cardiac genes, and loss of RBM20 causes dilated cardiomyopathy. Given its role in splicing, we hypothesized an important role for RBM20 in forming circular RNAs (circRNAs), a novel class of noncoding RNA molecules.

OBJECTIVE

To establish the role of RBM20 in the formation of circRNAs in the heart.

METHODS AND RESULTS

Here, we performed circRNA profiling on ribosomal depleted RNA from human hearts and identified the expression of thousands of circRNAs, with some of them regulated in disease. Interestingly, we identified 80 circRNAs to be expressed from the titin gene, a gene that is known to undergo highly complex alternative splicing. We show that some of these circRNAs are dynamically regulated in dilated cardiomyopathy but not in hypertrophic cardiomyopathy. We generated RBM20-null mice and show that they completely lack these titin circRNAs. In addition, in a cardiac sample from an RBM20 mutation carrier, titin circRNA production was severely altered. Interestingly, the loss of RBM20 caused only a specific subset of titin circRNAs to be lost. These circRNAs originated from the RBM20-regulated I-band region of the titin transcript.

CONCLUSIONS

We show that RBM20 is crucial for the formation of a subset of circRNAs that originate from the I-band of the titin gene. We propose that RBM20, by excluding specific exons from the pre-mRNA, provides the substrate to form this class of RBM20-dependent circRNAs.

A mutation in the glutamate-rich region of RNA-binding motif protein 20 causes dilated cardiomyopathy through missplicing of titin and impaired Frank-Starling mechanism

AIM

Mutations in the RS-domain of RNA-binding motif protein 20 (RBM20) have recently been identified to segregate with aggressive forms of familial dilated cardiomyopathy (DCM). Loss of RBM20 in rats results in missplicing of the sarcomeric gene titin (TTN). The functional and physiological consequences of RBM20 mutations outside the mutational hotspot of RBM20 have not been explored to date. In this study, we investigated the pathomechanism of DCM caused by a novel RBM20 mutation in human cardiomyocytes.

METHODS AND RESULTS

We identified a family with DCM carrying a mutation (RBM20(E913K/+)) in a glutamate-rich region of RBM20. Western blot analysis of endogenous RBM20 protein revealed strongly reduced protein levels in the heart of an RBM20(E913K/+ )carrier. RNA deep-sequencing demonstrated massive inclusion of exons coding for the spring region of titin in the RBM20(E913K/+ )carrier. Titin isoform analysis revealed a dramatic shift from the less compliant N2B towards the highly compliant N2BA isoforms in RBM20(E913K/+ )heart. Moreover, an increased sarcomere resting-length was observed in single cardiomyocytes and isometric force measurements revealed an attenuated Frank-Starling mechanism (FSM), which was rescued by protein kinase A treatment.

CONCLUSION

A mutation outside the mutational hotspot of RBM20 results in haploinsufficiency of RBM20. This leads to disturbed alternative splicing of TTN, resulting in a dramatic shift to highly compliant titin isoforms and an impaired FSM. These effects may contribute to the early onset, and malignant course of DCM caused by RBM20 mutations. Altogether, our results demonstrate that heterozygous loss of RBM20 suffices to profoundly impair myocyte biomechanics by its disturbance of TTN splicing.

Truncating Plakophilin-2 Mutations in Arrhythmogenic Cardiomyopathy Are Associated With Protein Haploinsufficiency in Both Myocardium and Epidermis

Background—

Arrhythmogenic cardiomyopathy (AC) is a hereditary cardiac condition associated with ventricular arrhythmias, heart failure, and sudden death. The disease is most often caused by mutations in the desmosomal gene for plakophilin-2 ( PKP2 ), which is expressed in both myocardial and epidermal tissue. This study aimed to investigate protein expression in myocardial tissue of patients with AC carrying PKP2 mutations and elucidate whether keratinocytes of the same individuals exhibited a similar pattern of protein expression.

Methods and Results—

Direct sequencing of 5 AC genes in 71 unrelated patients with AC identified 10 different PKP2 mutations in 12 index patients. One patient, heterozygous for a PKP2 nonsense mutation, developed severe heart failure and underwent cardiac transplantation. Western blotting and immunohistochemistry of the explanted heart showed a significant decrease in PKP2 protein expression without detectable amounts of truncated PKP2 protein. Cultured keratinocytes of the patient showed a similar reduction in PKP2 protein expression. Nine additional PKP2 mutations were investigated in both cultured keratinocytes and endomyocardial biopsies from affected individuals. It was evident that PKP2 mutations introducing a premature termination codon in the reading frame were associated with PKP2 transcript and protein levels reduced to ≈50%, whereas a missense variant did not seem to affect the amount of PKP2 protein.

Conclusions—

The results of this study showed that truncating PKP2 mutations in AC are associated with low expression of the mutant allele and that the myocardial protein expression of PKP2 is mirrored in keratinocytes. These findings indicate that PKP2 haploinsufficiency contributes to pathogenesis in AC.

Rapid spread of Schmallenberg virus-infected biting midges (Culicoides spp.) across Denmark in 2012

Detection of Schmallenberg virus RNA, using real-time RT-PCR, in biting midges (Culicoides spp.) caught at 48 locations in 2011 and four well-separated farms during 2012 in Denmark, revealed a remarkably rapid spread of virus-infected midges across the country. During 2012, some 213 pools of obsoletus group midges (10 specimens per pool) were examined, and of these, 35 of the 174 parous pools were Schmallenberg virus RNA positive and 11 of them were positive in the heads. Culicoides species-specific PCRs identified both C. obsoletus and C. dewulfi as vectors of Schmallenberg virus.

The LMNA mutation p.Arg321Ter associated with dilated cardiomyopathy leads to reduced expression and a skewed ratio of lamin A and lamin C proteins

Dilated cardiomyopathy (DCM) is a disease of the heart muscle characterized by cardiac chamber enlargement and reduced systolic function of the left ventricle. Mutations in the LMNA gene represent the most frequent known genetic cause of DCM associated with disease of the conduction systems. The LMNA gene generates two major transcripts encoding the nuclear lamina major components lamin A and lamin C by alternative splicing. Both haploinsuffiency and dominant negative effects have been proposed as disease mechanism for premature termination codon (PTC) mutations in LMNA. These mechanisms however are still not clearly established. In this study, we used a representative LMNA nonsense mutation, p.Arg321Ter, to shed light on the molecular disease mechanisms. Cultured fibroblasts from three DCM patients carrying this mutation were analyzed. Quantitative reverse transcriptase PCR and sequencing of these PCR products indicated that transcripts from the mutant allele were degraded by the nonsense-mediated mRNA decay (NMD) mechanism. The fact that no truncated mutant protein was detectable in western blot (WB) analysis strengthens the notion that the mutant transcript is efficiently degraded. Furthermore, WB analysis showed that the expression of lamin C protein was reduced by the expected approximately 50%. Clearly decreased lamin A and lamin C levels were also observed by immunofluorescence microscopy analysis. However, results from both WB and nano-liquid chromatography/mass spectrometry demonstrated that the levels of lamin A protein were more reduced suggesting an effect on expression of lamin A from the wild type allele. PCR analysis of the ratio of lamin A to lamin C transcripts showed unchanged relative amounts of lamin A transcript suggesting that the effect on the wild type allele was operative at the protein level. Immunofluorescence microscopy analysis showed no abnormal nuclear morphology of patient fibroblast cells. Based on these data, we propose that heterozygosity for the nonsense mutation causes NMD degradation of the mutant transcripts blocking expression of the truncated mutant protein and an additional trans effect on lamin A protein levels expressed from the wild type allele. We discuss the possibility that skewing of the lamin A to lamin C ratio may contribute to ensuing processes that destabilize cardiomyocytes and trigger cardiomyopathy.

Mutated desmoglein-2 proteins are incorporated into desmosomes and exhibit dominant-negative effects in arrhythmogenic right ventricular cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a hereditary cardiac condition associated with ventricular arrhythmias, heart failure, and sudden death. The most frequent ARVC genes encode desmosomal proteins of which mutations in desmoglein-2 (DSG2), account for 10%-20% of cases. This study aimed to investigate how DSG2 mutations contribute to the pathogenesis of ARVC. Initial mutation analysis of DSG2 in 71 probands identified the first family reported with recessively inherited ARVC due to a missense mutation. In addition, three recognized DSG2 mutations were identified in 12 families. These results and further mutation analyses of four additional desmosomal genes indicated that ARVC caused by DSG2 mutations is often transmitted by recessive or digenic inheritance. Because desmosomal proteins are also expressed in skin tissue, keratinocytes served as a cell model to investigate DSG2 protein expression by Western blotting, 2D-PAGE, and liquid chromatography-mass spectrometry. The results showed that heterozygous mutation carriers expressed both mutated and wild-type DSG2 proteins. These findings were consistent with the results obtained by immunohistochemistry of endomyocardial biopsies and epidermal tissue of mutation carriers, which indicated a normal cellular distribution of DSG2. The results suggested a dominant-negative effect of the mutated DSG2 proteins because they were incorporated into the desmosomes.

Detection of African swine fever virus DNA in blood samples stored on FTA cards from asymptomatic pigs in Mbeya region, Tanzania

The aim of the study was to assess whether blood samples collected onto FTA(®) cards could be used in combination with real-time PCR for the detection of African swine fever virus (ASFV) DNA in samples from resource-poor settings under the assumption that asymptomatically (sub-clinically) infected pigs may be present. Blood samples were collected from clinically healthy pigs from Mbeya Region, Tanzania. The blood samples were stored on FTA(®) cards and analysed by real-time PCR assays in duplicate; three pigs had high levels of viral DNA (Ct values of 27-29), and three pigs had a low level of viral DNA (Ct 36-45). Four pigs were positive in one of the duplicate samples only, but clear products of the expected size were obtained when the reactions were analysed by gel electrophoresis. For comparison, blood samples from pigs experimentally infected with either a pathogenic (OURT T88/1) or a non-pathogenic (OURT T88/3) isolate of ASFV were collected, stored on FTA(®) cards and analysed in the same way. The blood from pigs infected with the OURT T88/1 isolate showed high levels of viral DNA (Ct 22-33), whereas infection with non-pathogenic OURT T88/3 isolate resulted in only low levels of viral DNA (Ct 39) in samples collected at 10-14 days after inoculation.

ASFV in Tanzania: asymptomatic pigs harbor virus of molecular similarity to Georgia 2007

In 2011 African swine fever virus (ASFV) genome was detected in asymptomatic pigs in field samples in Mbeya, Tanzania. The aim of this paper is to partly characterize the virus that was harbored in these pigs and furthermore to confirm, by a second sampling, the latest occurrence of ASFV in the study area. ASFV genome was detected in serum from 10 out of 127 healthy European/crossbreed pigs. ASFV DNA was polymerase chain reaction (PCR) amplified and sequenced from sera with high viral loads using primers targeting p54 or p72. Both p54 and p72 had total identity to ASFV Genotype II (Georgia 2007/1). The ASFV epidemiology in Mbeya was studied in a new collection of 804 pig sera obtained in 2012. The antibody prevalence in four age groups (3-6 months.; 7-12 months; 13-18 months or 19-36 months) was 3-5%; all antibody positive sera were analyzed by PCR with negative results. The presence of antibodies in 3-month-old pigs confirms the circulation of ASFV in Mbeya several months after our detection of ASFV in asymptomatic pigs. The initial blood samples were obtained on Whatman FTA filter papers as dried blood samples. The samples were stored under field conditions and ASFV could be sequenced in DNA eluted 10 months later, showing the use of FTA samples. Studies on the genetic breed of the pigs are needed as well as sequence studies including the variable region of ASFV to elucidate why asymptomatic pigs with high viral loads were detected.

Protein expression studies of desmoplakin mutations in cardiomyopathy patients reveal different molecular disease mechanisms

Mutations in the gene for desmoplakin (DSP) may cause arrhythmogenic right ventricular cardiomyopathy (ARVC) and Carvajal syndrome (CS). Desmoplakin is part of all desmosomes, which are abundantly expressed in both myocardial and epidermal tissue and serve as intercellular mechanical junctions. This study aimed to investigate protein expression in myocardial and epidermal tissue of ARVC and CS patients carrying DSP mutations in order to elucidate potential molecular disease mechanisms. Genetic investigations identified three ARVC patients carrying different heterozygous DSP mutations in addition to a homozygous DSP mutation in a CS patient. The protein expression of DSP in mutation carriers was evaluated in biopsies from myocardial and epidermal tissue by immunohistochemistry. Keratinocyte cultures were established from skin biopsies of mutation carriers and characterized by reverse transcriptase polymerase chain reaction, western blotting, and protein mass spectrometry. The results showed that the mutation carriers had abnormal DSP expression in both myocardial and epidermal tissue. The investigations revealed that the disease mechanisms varied accordingly to the specific types of DSP mutation identified and included haploinsufficiency, dominant-negative effects, or a combination hereof. Furthermore, the results suggest that the keratinocytes cultured from patients are a valuable and easily accessible resource to elucidate the effects of desmosomal gene mutations in humans.

Bat rabies surveillance in Europe

Rabies is the oldest known zoonotic disease and was also the first recognized bat associated infection in humans. To date, four different lyssavirus species are the causative agents of rabies in European bats: the European Bat Lyssaviruses type 1 and 2 (EBLV-1, EBLV-2), the recently discovered putative new lyssavirus species Bokeloh Bat Lyssavirus (BBLV) and the West Caucasian Bat Virus (WCBV). Unlike in the new world, bat rabies cases in Europe are comparatively less frequent, possibly as a result of varying intensity of surveillance. Thus, the objective was to provide an assessment of the bat rabies surveillance data in Europe, taking both reported data to the WHO Rabies Bulletin Europe and published results into account. In Europe, 959 bat rabies cases were reported to the RBE in the time period 1977-2010 with the vast majority characterized as EBLV-1, frequently isolated in the Netherlands, North Germany, Denmark, Poland and also in parts of France and Spain. Most EBLV-2 isolates originated from the United Kingdom (UK) and the Netherlands, and EBLV-2 was also detected in Germany, Finland and Switzerland. Thus far, only one isolate of BBLV was found in Germany. Published passive bat rabies surveillance comprised testing of 28 of the 52 different European bat species for rabies. EBLV-1 was isolated exclusively from Serotine bats (Eptesicus serotinus and Eptesicus isabellinus), while EBLV-2 was detected in 14 Daubenton's bats (Myotis daubentonii) and 5 Pond bats (Myotis dasycneme). A virus from a single Natterer's bat (Myotis nattereri) was characterized as BBLV. During active surveillance, only oral swabs from 2 Daubenton's bats (EBLV-2) and from several Eptesicus bats (EBLV-1) yielded virus positive RNA. Virus neutralizing antibodies against lyssaviruses were detected in various European bat species from different countries, and its value and implications are discussed.

Improved safety for molecular diagnosis of classical rabies viruses by use of a TaqMan real-time reverse transcription-PCR "double check" strategy

To improve the diagnosis of classical rabies virus with molecular methods, a validated, ready-to-use, real-time reverse transcription-PCR (RT-PCR) assay was developed. In a first step, primers and 6-carboxyfluorescien-labeled TaqMan probes specific for rabies virus were selected from the consensus sequence of the nucleoprotein gene of 203 different rabies virus sequences derived from GenBank. The selected primer-probe combination was highly specific and sensitive. During validation using a sample set of rabies virus strains from the virus archives of the Friedrich-Loeffler-Institut (FLI; Germany), the Veterinary Laboratories Agency (VLA; United Kingdom), and the DTU National Veterinary Institute (Lindholm, Denmark), covering the global diversity of rabies virus lineages, it was shown that both the newly developed assay and a previously described one had some detection failures. This was overcome by a combined assay that detected all samples as positive. In addition, the introduction of labeled positive controls (LPC) increased the diagnostic safety of the single as well as the combined assay. Based on the newly developed, alternative assay for the detection of rabies virus and the application of LPCs, an improved diagnostic sensitivity and reliability can be ascertained for postmortem and intra vitam real-time RT-PCR analyses in rabies reference laboratories.

Bluetongue in Denmark during 2008

Following the first ever case of bluetongue in Denmark during late 2007, further outbreaks were observed in Denmark during 2008, despite vaccination against bluetongue virus (BTV) serotype 8 (BTV-8) in the southern part of the country. In total, 15 separate outbreaks of infection were identified, mostly as a result of clinical suspicions but also because of surveillance of bulk milk samples. These outbreaks led to extensions of the original vaccination zone planned for 2008. Blood samples from clinical suspects were analysed using ELISA and real-time RT-PCR assays for the presence of anti-BTV antibodies and viral RNA, respectively. A newly infected calf from the primary outbreak in 2008 was studied for a period of three months, during which time it seroconverted to BTV, but the presence of viral RNA in its blood was maintained throughout this time. Each outbreak was caused by BTV-8, as determined by a serotype-specific real-time RT-PCR assay. Furthermore, the nucleotide sequence of a portion of segment 2 of the viral RNA (encoding the outer capsid protein VP2) from the samples analysed was identical to the BTV-8 segment 2 that circulated in the Netherlands during 2006.

Development of a real-time RT-PCR assay based on primer-probe energy transfer for the detection of all serotypes of bluetongue virus

A real-time RT-PCR assay based on the primer-probe energy transfer (PriProET) was developed to detect all 24 serotypes of bluetongue virus (BTV). BTV causes serious disease, primarily in sheep, but in other ruminants as well. A distinguishing characteristic of the assay is its tolerance toward mutations in the probe region. Furthermore, melting curve analysis following immediately PCR confirms specific probe hybridization and can reveal mutations in the probe region by showing a difference in the melting point. The assay sensitivity was in the range of 10-100 target copies and the specificity tests showed no positive results for heterologous pathogens. The assay was tested on clinical samples from BTV 8 outbreaks in Sweden and Denmark in 2008. The lowest detection limit for that serotype, determined with PCR standards, was 57 genome copies. The assay sensitivity for some other serotypes that circulate currently in Europe was also determined. BTV 2, 4, 9 and 16 were tested on available cell culture samples and the detection limits were 109, 12, 13 and 24 copies, respectively. This assay provides an important tool for early and rapid detection of a wide range of BTV strains, including emerging strains.

Improved diagnosis for nine viral diseases considered as notifiable by the world organization for animal health

Nine viral diseases included in the World Organization for Animal Health list of notifiable diseases (former list A) were chosen for their contagiousness and high capacity of spreading to improve their diagnosis using new and emerging technologies. All the selected diseases--foot-and-mouth disease, swine vesicular disease, vesicular stomatitis, classical swine fever, African swine fever, bluetongue, African horse sickness, Newcastle disease and highly pathogenic avian influenza--are considered as transboundary diseases, which detection causes the prohibition of livestock exportation, and, thus, it leads to high economical losses. The applied diagnostic techniques can fall into two categories: (i) nucleic-acid detection, including padlock probes, real-time PCR with TaqMan, minor groove binding probes and fluorescence energy transfer reaction probes, isothermal amplification like the Cleavase/Invader assay or the loop-mediated amplification technology and the development of rapid kits for 'mobile' PCR and (ii) antigen-antibody detection systems like simplified and more sensitive ELISA tests. Besides, internal controls have been improved for nucleic acid-detecting methods by using an RNA plant virus--Cowpea Mosaic Virus--to ensure the stability of the RNA used as a positive control in diagnostic real-time RT-PCR assays. The development of these diagnosis techniques has required the joint efforts of a European consortium in which nine diagnostic laboratories and an SME who have collaborated since 2004 within the European Union-funded Lab-on-site project. The results obtained are shown in this paper.

Well-known quorum sensing inhibitors do not affect bacterial quorum sensing-regulated bean sprout spoilage

AIM

To investigate the potential of quorum sensing inhibitors (QSI) as food preservative agents in a food product, where bacterial spoilage is controlled by quorum sensing (QS).

METHODS AND RESULTS

The effects of well-known QSI were tested on spoilage phenotypes and on QS-regulated genes of a bean sprout spoiling bacterial isolate (Pectobacterium A2JM) in laboratory substrates and in a bean sprout model system. The acylated homoserine lactones (AHL) analogues PenS-AHL and HepS-AHL decreased the specific protease activity of Pectobacterium A2JM in broth but did not reduce the expression of a QS-regulated secretion protein, and were without effect on soft rot of bean sprouts. The QSI ProS-AHL, furanone C-30, patulin, penicillic acid and 4-nitropyridine-N-oxide did not have any effect on protease activity, on gene expression or bean sprout appearance at nongrowth inhibitory concentrations. Extracts from garlic and bean sprouts induced the QS system of Pectobacterium in bean sprouts and a broth system, respectively.

CONCLUSIONS

Among the several well-known QSI compounds, only PenS-AHL and HepS-AHL, inhibited QS-regulated protease activity of Pectobacterium A2JM in broth cultures, but had no effect on bean sprout spoilage.

SIGNIFICANCE AND IMPACT OF THE STUDY

The QSI compounds must be selected in the specific system in which they are to function and they cannot easily be transferred from one QS system to another.

Vertical transmission of bovine viral diarrhoea virus (BVDV) in mousedeer (Tragulus javanicus) and spread to domestic cattle

This study investigates the transmission of bovine viral diarrhoea virus (BVDV) 1f from a persistently infected (PI) lesser Malayan mousedeer to two bovine calves. Different contact routes to two calves were analysed: 1) aerosol contact between two adjacent pens without physical contact; 2) indirect contact by use of common utensils; 3) direct nose-to-nose contact for 30 seconds. One of the calves was infected either by aerosol or indirect contact. The virus sequence in 247 nucleotides in the 5'-UTR was 100% identical in mousedeer and calf. To elucidate the distribution of BVDV within the affected mousedeer family the captive population in a Zoo was analysed. The maternal line of PI animals was maintained, whereas a PI male was able to reproduce and have a non-PI calf. As a consequence of this, six female PI mousedeer were killed; subsequent autopsies did not reveal any lesions. Sequencing mousedeer BVD virus in the E2 region (420 nucleotides) through 4 generations showed only 7 mutations, which were maintained from mother to offspring.

Development of a real-time PCR assay based on primer-probe energy transfer for the detection of swine vesicular disease virus

A real-time PCR assay based on primer-probe energy transfer (PriProET) was developed to detect swine vesicular disease virus (SVDV). Specificity tests of SVDV and heterologous virus showed specific amplification of SVDV strains only. The amplification plot for the closely related Coxsackievirus B5 remained negative. The sensitivity of assay was five copies of viral genome equivalents. A key point of the assay is tolerance toward mutations in the probe region. Melting curve analysis directly after PCR, with determination of probe melting point, confirmed specific hybridisation of the SVDV strains. Eight of twenty SVDV strains tested, revealed shifted melting points that indicated mutations in the probe region. All predicted mutations were confirmed by nucleotide sequencing. With the PriProET system there is a chance to identify phylogenetically divergent strains of SVDV, which may appear negative in other probe-based real-time PCR assays. At the same time, any difference in melting points may provide an indication of divergence in the probe region. The high sensitivity, specificity, and tolerance toward mutations in the probe region of the SVDV PriProET assay may improve the early and rapid detection of a wide range of SVDV strains, allowing reduced turnaround time and the use of high-throughput, automated technology.

Persistent BVDV infection in mousedeer infects calves

Bovine virus diarrhoea virus (BVDV)-1f was isolated from a Lesser Malayan Mousedeer in Copenhagen Zoo during a routine screening. Analysis of animals related to the Copenhagen mousedeer revealed that its mother and all siblings were virus positive, a pattern also seen for persistently infected (PI) cattle. BVDV could be transmitted from the PI mousedeer to a calf after indirect contact. The host spectrum for BVDV seems to be even wider than expected; the implications for BVDV control are discussed.

Development of a novel quantitative real-time RT-PCR assay for the simultaneous detection of all serotypes of foot-and-mouth disease virus

Foot-and-mouth disease virus (FMDV) spreads extremely fast and the need for rapid and robust diagnostic virus detection systems was obvious during the recent European epidemic. Using a novel real-time RT-PCR system based on primer-probe energy transfer (PriProET) we present here an assay targeting the 3D gene of FMDV. The assay was validated for the efficacy to detect all known FMDV serotypes. The test method was linear over a range of at least 7 orders of magnitude and the detection limit was below the equivalent of 10 genomic copies. Analysing recent African probang samples the method was able to detect FMDV in materials from both cattle and buffalo. When compared to traditional virus cultivation the virus detection sensitivity was similar but the RT-PCR method can provide a laboratory result much faster than virus cultivation. The real-time PCR method confirms the identity of the amplicon by melting point analysis for added specificity and at the same time allows the detection of mutations in the probe region. As such, the described new method is suitable for the robust real-time detection of index cases caused by any serotype of FMDV.

Characterisation of a pestivirus isolated from persistently infected mousedeer ( Tragulus javanicus)

Serum samples from the male Mousedeer A and the mother, father and sister of A were tested for bovine virus diarrhoea viruses (BVDV) by isolation, and for BVDV antibodies by blocking ELISA and homologous neutralisation test. Further, RNA was extracted and tested by RT-PCR protocol analysing the 5'-untranslated region and the E2 gene of pestivirus. The RT-PCR products were subsequently sequenced. Mousedeer A was positive in virus isolation on three occasions (days 1, 19 and 40) and by RT-PCR. The sister and mother of Mousedeer A were also found virus positive by isolation and RT-PCR. Mousedeer A, its sister and its mother, all had an antibody neutralisation titer below 10. The father of A was virus negative but was positive in the blocking antibody ELISA and had a high neutralisation antibody titer. The repeated detection of BVDV in Mousedeer A, the high amount of virus in serum, the lack of antibodies and the virus positive family members documented that the mousedeer were persistently infected with a pestivirus. The father of A probably had an acute infection resulting in antibodies to pestivirus and viral clearance. Sequence analysis and phylogenetic analysis revealed that the mousedeer pestivirus was closely related to BVDV Type 1f. The existences of persistently infected animals in non-domestic species have great implications for BVDV eradication campaigns in cattle.

Synthesis of new 3- and 4-substituted analogues of acyl homoserine lactone quorum sensing autoinducers

The quorum sensing mechanism in Gram-negative bacteria uses small intercellular signal molecules, N-acyl-homoserine lactones (AHLs), to control transcription of specific genes in relation to population density. In this communication, we describe the parallel synthesis of new AHL analogues, in which substituents have been introduced into the 3- and 4-positions of the lactone ring. These analogues have been screened for their ability to activate and inhibit a Vibrio fischeri LuxI/LuxR-derived quorum sensing reporter system.

Assessment of flhDC mRNA levels in Serratia liquefaciens swarm cells

We reported previously that artificial overexpression of the flhDC operon in liquid-grown Serratia liquefaciens resulted in the formation of filamentous, multinucleated, and hyperflagellated cells that were indistinguishable from surface-induced swarm cells (L. Eberl, G. Christiansen, S. Molin, and M. Givskov, J. Bacteriol. 178:554-559, 1996). In the present report we show by means of reporter gene measurements, Northern analysis, and in situ reverse transcription-PCR that the amount of flhDC mRNA in surface-grown swarm cells does not exceed the maximum level found in nondifferentiated, vegetative cells. This suggests that surface-induced S. liquefaciens swarm cell differentiation, although dependent on flhDC gene expression, does not occur through elevated flhDC mRNA levels.

Seizures with onset in the sensorimotor face area: clinical patterns and results of surgical treatment in 20 patients

It is not generally appreciated that intractable seizures involving the face area are amenable to surgical treatment. Twenty patients with onset of sensorimotor seizures in the face area of the pre- and postcentral gyri have been studied and surgically treated since 1948. Seizures started in the face, tongue, or throat, followed by diverse patterns depending on spread of seizure activity. Two patients had epilepsia partialis continua; 6 had either tonic or atonic drop attacks. All patients had pre- and postcentral face area resections, 12 in the dominant hemisphere. In addition, 3 had more extensive postcentral removal, 7 had temporal lobe, and 4 had small separate or contiguous frontal or parietal resection. Because the seizures were not sufficiently reduced by the first operation, 6 required reoperation; 4 of these patients had residual epileptiform activity on electrocorticogram (ECoG) after the first resection. Three patients had new neurologic signs that did not return to the preoperative level, but in 2 of them the deficit related mainly to higher resection in the central area. All but 2 of these 20 patients had at least moderate seizure reduction. Corticectomy can be performed for treatment of seizures arising in the lower central area and usually does not lead to significant permanent neurologic deficit.

A prospective comparison of iotrolan and iohexol in lumbar myelography

In a double-blind study 238 patients were examined with lumbar myelography using iotrolan or iohexol in randomized sequence in order to evaluate the image quality, the safety and tolerance of iotrolan by monitoring the adverse effects with special attention to late reactions. There were no serious complications. On the first day 28 patients (24%) had headache after iotrolan and 41 (34%) after iohexol. This difference was not significant, and these frequencies are similar to those found after spinal puncture alone. The second most frequent side effect was neck pain; the duration of neck pain were significantly longer after myelography with iohexol than with iotrolan. There was a significantly higher frequency of adverse effects in females the first 24 hours, but during examination and on days 2 to 4 there were no differences between males and females. Anamnestic information or myelographic diagnosis could not predict which patients would have side effects. The image quality was excellent or good in all examinations but one. It is concluded that iotrolan is a safe contrast medium well suited for lumbar myelography.

Metastatic spinal cord compression secondary to lung cancer

PURPOSE

Metastatic spinal cord compression (MSCC) is a disabling complication to cancer, the optimal treatment for which is not settled. An analysis was performed for all patients with MSCC secondary to lung cancer in East Denmark from 1979 to 1988.

PATIENTS AND METHODS

The total series included 102 cases with small-cell carcinoma (SCLC; 40%), adenocarcinoma (ACL; 26%), squamous cell carcinoma (SQLC; 18%) and large-cell carcinoma (LCC; 9%). Symptoms, clinical presentations, and therapeutic results are described.

RESULTS

The outcome of treatment depended fundamentally on the patient's neurologic condition at the time of the diagnosis. All patients with SCLC who were able to walk at the time of MSCC remained ambulatory, whereas 15% of the nonambulatory SCLC patients regained walking ability. In non-SCLC, 95% of patients continued to be able to walk, whereas 22% regained the ability to walk. No major differences in the immediate outcome of treatment between the various histologic types of lung cancer and the different treatment modalities were observed; however, 82% of the patients with non-SCLC benefited from treatment with laminectomy followed by radiotherapy (RT) compared with either laminectomy (47%) or RT (39%) alone (P = .03, chi 2 test). The group of patients who were treated with laminectomy followed by RT had a better survival (median value, 3.5; range, 0 to 132 months) than patients who were treated with either laminectomy (median value, 1.5; range, 0 to 32 months) or RT (median value, 1; range, 0 to 59 months) alone (P = .03, log-rank test). No significant difference was observed in survival between the various histologic types of lung cancer (P = .18, log-rank test).

CONCLUSION

Despite a short survival, early diagnosis and immediate treatment is crucial because it may preserve the gait function in 97% of lung cancer patients who develop malignant spinal cord compression.

Functional hemispherectomy: EEG findings, spiking from isolated brain postoperatively, and prediction of outcome

We reviewed the prognostic significance of preoperative EEG findings in 25 patients who underwent functional hemispherectomy. Bilateral independent epileptogenic foci, found in five patients, generally indicate a less satisfactory outcome, with only three of the five patients becoming seizure free following hemispherectomy. In contrast, abnormalities of background activity over the "good" hemisphere, multifocal epileptic activity confined to the side of operation, or bilaterally synchronous discharges were associated with a good outcome and should not be considered as contraindications to operation. Postoperatively, discharges may occur in the functionally isolated frontal and occipital cortex, which are benign, with no other clinical significance than showing that the isolated cortex remains viable and continues to generate epileptogenic potentials.