Arrhythmogenic right ventricular cardiomyopathy – evolution of electrocardiographic markers during long-term follow-up prior to ascertainment of diagnosis

Background

Depolarization and repolarization abnormalities are part of the diagnostic Task Force Criteria of 2010 (TFC2010) for arrhythmogenic right ventricular cardiomyopathy (ARVC). These abnormalities are thought to be progressive but have also been described as dynamic and sometimes reversible. Evolution of ECG abnormalities prior to clinical ARVC diagnosis is poorly studied.

Objective

To assess the evolution of ECG depolarization and repolarization characteristics in patients with ARVC prior to diagnosis and to identify markers of disease progression at a preclinical stage.

Methods

353 patients with definite ARVC from Sweden, Denmark, the Netherlands and Canada with at least one 12-lead digital ECG (65% males, 67% probands, 56% mutation carriers, median age at diagnosis 42 [IQR 29–53] years and median age at first ECG 44 [30–55] years) were included. Digital ECGs were extracted from regional ECG archives. ECGs with left bundle branch block, ventricular pacing or recorded either prior to 15 years of age or after heart transplantation were excluded. Remaining 6,871 ECGs were digitally processed and automatically analysed using the Glasgow algorithm. Median values for overall QRS duration, terminal activation delay (TAD) in lead V1 as well as amplitudes of QRS-T-components in precordial leads per patient per year were used for analyses and graphically represented using Lowess smoothing with cubic splines (Figure 1). Blue lines indicate smoothed conditional mean with 95% confidence interval (shadow). Time “0” (red line) indicates the time when TFC2010 were fulfilled for definite diagnosis.

A database of 18,564 anonymized digital ECGs (58% males, median age at latest ECG 41 years [IQR 32–52]) who were in contact with health care during 2020–2021 was processed using the same exclusion criteria and signal-processing methodology as in the ARVC group and used as a reference (black line).

Results

TAD in lead V1 and overall QRS duration demonstrated a significant increase years before ARVC diagnosis, and significant reductions were seen in QRS-T voltages measured as R wave amplitude, QRS amplitude (the absolute sum of R wave and S wave), and T wave amplitude (Table 1 and Figure 1). The changes were seen in all precordial leads, not only the right-sided, and visually diverging from the controls.

Conclusion

Development of the ARVC ECG phenotype started several years before diagnosis and continued afterwards. QRS duration and TAD increased, QRS voltages decrease, and T wave amplitude decreased eventually leading to T wave inversion. These changes might be visually assessed but also measured with available ECG software. These findings may be clinically useful in the screening and follow-up of ARVC relatives.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Governmental funding of clinical research (ALF), Region Ostergotland, Sweden.The Swedish Heart-Lung Foundation.

CDC field triage criteria accurately predicts outcomes in high impact trauma

BACKGROUND

The precision of emergency medical services (EMS) triage criteria dictates whether an injured patient receives appropriate care. The trauma triage protocol is a decision scheme that groups patients into triage categories of major, moderate and minor. We hypothesized that there is a difference between trauma triage category and injury severity score (ISS).

METHODS

This retrospective, observational study was conducted to investigate a difference between trauma triage category and ISS. Bivariate analysis was used to test for differences between the subgroup means. The differences between the group means on each measure were analyzed for direction and statistical significance using ANOVA for continuous variables and chi square tests for categorical variables. Logistic and linear regressions were performed to evaluate factors predicting mortality, ICU length of stay.

RESULTS

With respect to trauma triage category, our findings indicate that minor and moderate triage categories are similar with respect to ISS, GCS, ICU LOS, hospital LOS, and mortality. However, after excluding for low impact injuries (falls), differences between the minor and moderate categories were evident when comparing to ISS, GCS, ICU LOS, and hospital LOS. Additionally, after excluding for low impact injures, ISS, ICU LOS, and hospital stay were found to correlate well with trauma triage category.

CONCLUSIONS

In this retrospective, observational study significant differences were not seen when comparing ISS with the trauma triage categories of moderate and minor during our initial analysis. However, a difference was found after excluding for low impact injuries. These findings suggest that CDC criteria accurately predicts outcomes in high impact trauma.

Surgical and non-surgical treatment of inguinal hernia during non-elective admissions in the Nationwide Readmissions Database

INTRODUCTION

Inguinal hernia repair is one of the most common surgical operations, yet the optimal treatment strategy remains undefined. Treatment of symptomatic inguinal hernias include both surgical and non-surgical approaches. The objective of this study was to determine differences in population, readmission rates, and costs between operative and non-operative approaches for patients admitted non-electively for an inguinal hernia in a national dataset. In addition, we sought to define the baseline characteristics of the two groups and identify potential predictive factors in the non-surgically managed subgroup who were readmitted and treated operatively within 90 days of their first visit.

METHODS

This study was a retrospective review of data from the Nationwide Readmissions Database (NRD) from 2010 to 2014. Patients above age 18 who were admitted non-electively for a primary diagnosis of inguinal hernia were included. Patients whose length of stay was < 1% or > 95% percentile or died during the initial visit were excluded. Readmissions within 90 days of the initial visit were flagged. Patients were classified according to initial management strategy: operative versus non-operative. Demographic, clinical, and organizational characteristics were compared between the two cohorts.

RESULTS

14,249 patients met inclusion criteria and were operative (n = 8996, 63.13%) and non-operative (n = 5255, 36.88%) cohorts. When comparing the two groups, readmission rate was lower (0.49% for surgical, 1.78% for non-surgical, p < 0.01), mean length of stay (LOS) longer (3.27 [SE = 0.05] days for surgical, 2.76 days [SE = 0.06] for non-surgical, p < 0.01), and mean total cost higher ($9597 for surgical, $7167 for non-surgical, p < 0.01) in surgically treated patients. The non-surgical population was on average older (63.05 years for surgical, 64.52 years for non-surgical, p < 0.01) with more chronic conditions (3.57 for surgical, 4.05 for non-surgical, p < 0.01). Of the patients initially managed non-surgically, 1.78% (n = 91) were readmitted, and of them, 62.63% (n = 57) were readmitted and managed surgically within 90 days of initial admission (i.e., crossed over from watchful waiting to surgical treatment). Average number of chronic conditions (3.79 versus 4.03, p = 0.74), average number of comorbidities (2.26 versus 2.18, p = 0.87), and average total number of ICD-9 discharge codes (7.44 versus 8.23 p = 0.54 did not differ significantly between the operative versus non-operative sample of the readmitted population. The total cost ($5562.38 versus $8737.28, p = 0.01) was greater in the operative versus non-operative sample.

CONCLUSION

Watchful-waiting strategy is the most common treatment approach in patients admitted non-electively for symptomatic inguinal hernia. Readmission after non-elective hospitalization for inguinal hernia is rare, but surgical intervention decreased the likelihood of readmission compared to non-operative management, while also increasing LOS and cost of care. Our data supports a patient centric approach to the management; non-surgical treatment is a viable temporary option even in symptomatic inguinal hernias, while surgical treatment may reduce the likelihood of future readmission.

No prognostic benefit of multimodality imaging-guided left ventricular lead placement in cardiac resynchronization therapy: Long-term follow-up of the ImagingCRT study

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Aarhus University, the Danish Heart Foundation, Health Research Foundation of Central Denmark Region, and Gangstedfonden.

Background

 

Observational data indicate that left ventricular (LV) lead placement at the latest contracting region and separate from myocardial scar is associated with improved prognosis in cardiac resynchronization therapy (CRT). In a double-blinded, randomized controlled trial (ImagingCRT), we tested the strategy of multimodality imaging-guided LV lead placement towards the latest mechanically activated non-scarred myocardial segment in CRT. Patients were included between 2011 and 2014 and allocated either to (1) imaging-guided LV lead placement using cardiac computed tomography, 99mTechnetium myocardial perfusion imaging, and speckle-tracking echocardiography (imaging group, n = 89) or to (2) routine LV lead implantation in a posterolateral region with late electrical activation (control group, n = 93). The multimodality imaging-guided strategy was found to reduce proportion of non-responders to CRT after 6 months. Impact on long-term clinical outcome is unknown.

Purpose

To evaluate the long-term effect of individualized multimodality imaging-guided LV lead placement compared to a routine fluoroscopic approach on the composite endpoint of death or heart failure (HF) hospitalization after CRT.

Method

We reviewed follow-up data until November 2020 for all 182 patients included in the ImagingCRT trial for the occurrence of HF hospitalization and all-cause death. Continuous variables are presented as median (interquartile range) or mean ± standard deviation. We used Kaplan-Meier plot and Cox proportional hazard regression analysis (unadjusted) to assess the risk of HF hospitalization and all-cause death, and used log-rank test for comparison between the two groups.

Results

All patients had standard CRT indication (left bundle branch block, New York Heart Association functional class II/ III/ IV 84 [46%]/ 92 [51%]/ 6 [3%], LV ejection fraction 25 ± 6%, QRS width 166 ± 22 milliseconds). Mean age was 70 ± 9 years, and 39 (21%) were female. During a median follow-up period of 6.7 years (3.3–7.9 years), the proportion of patients meeting the composite endpoint of HF hospitalization (n = 45 [25%]) or all-cause death (n = 56 [31%]) was 60% (n = 53) in the imaging group compared with 52% (n = 48) in the control group (hazard ratio [HR] 1.22, 95% confidence interval [CI] 0.83–1.81, p = 0.31) (Figure 1).

Neither the risk of HF hospitalization (HR 1.11, 95% CI 0.62–1.99, p = 0.72) or of all-cause death differed between the two groups (HR 1.23, 95% CI 0.82–1.85, p = 0.32).

Conclusion

An individualized multimodality imaging-guided strategy targeting LV lead placement towards the latest mechanically activated non-scarred myocardial segment during CRT implantation did not reduce the composite outcome of HF hospitalization or all-cause death during long-term follow-up. Abstract Figure 1

MicroCT Imaging of Heart Valve Tissue in Fluid

BACKGROUND

Heart valve computational models require high quality geometric input data, commonly obtained using micro-computed tomography. Whether in the open or closed configuration, most studies utilize dry valves, which poses significant challenges including gravitational and surface tension effects along with desiccation induced mechanical changes.

OBJECTIVE

These challenges are overcome by scanning in a stress-free configuration in fluid. Utilizing fluid backgrounds however reduces overall contrast due to the similar density of fluid and tissue.

METHODS

The work presented here demonstrates imaging of the mitral valve by utilizing an iodine-based staining solution to improve the contrast of valve tissue against a fluid background and investigates the role of stain time and concentration.

RESULTS

It is determined that an Olea europaea oil bath with a relatively high concentration, short stain time approach produces high quality imagery suitable for creating accurate 3D renderings.

CONCLUSIONS

Micro-CT scanning of heart valves in fluid is shown to be feasible using iodine staining techniques.

P870A genetic risk score is associated with increased coronary plaque burden but not specific plaque features: a coronary computed tomography study

Background

Genetic risk scores (GRSs) based on risk variants identified from genome-wide association studies (GWASs) predict coronary artery disease (CAD) risk. However, it is unknown whether the GRS is associated with coronary plaque burden or specific high-risk plaque features responsible for the clinical disease onset.

Purpose

To investigate if a GRS is associated with coronary plaque burden and specific plaque characteristics, in patients with suspected stable CAD referred for coronary computed tomography angiography (CTA).

Methods

We consecutively included and genotyped 1645 patients undergoing coronary CTA. Using LDPred, a previously validated GRS was calculated as the weighted sum of the number of CAD risk variants identified from the CARDIoGRAMplusC4D GWAS meta-analysis. Plaques were evaluated using an 18-segment model and characterized by stenosis severity (0%, 1–49%, 50–69%, 70–100%) and composition (calcified (>80% calcified), mixed-calcified (50–80% calcified), mixed-soft (20–50% calcified), or soft (<20% calcified)). The segment stenosis score and the coronary artery calcium score (CACS) were used as measures of plaque burden. Multivariate regression models were used to assess the effect per standard deviation (SD) of the GRS with adjustment for age, sex, hypertension, hypercholesterolemia, BMI, chest pain symptoms, and active smoking.

Results

For each SD increase in the GRS, the segment stenosis score increased with 49% (p=8.6e-27) and CACS increased with 110% (p=2.3e-24). The GRS was associated with a higher risk of plaque stenosis >50% (OR: 1.74, p=3.2e-15), calcified (OR: 1.65, p=3.0e-16), mixed-calcified (OR: 1.64, p=1.5e-8), mixed-soft (OR: 1.44, p=1.6e-6), and soft plaques (OR: 1.40, p=3.0e-6), and all coronary vessels were more often affected with plaques (all p-values <1.0e-4).

When analyzing the plaque characteristics (3007 plaques in 849 patients), the GRS was associated with stenosis severity (OR per severity category: 1.15 (p=0.005), but not with extent of calcification, proximal location, or presence in any of the major coronary vessels (all p-values >0.05).

GRS and Plaque burden

Conclusion

The GRS was strongly associated with the extent and severity of CAD at coronary CTA, but not any specific plaque characteristics per se. The results may suggest that polygenic risk based on large CAD-GWAS increases CAD risk through increased coronary plaque burden rather than specific plaque features.

P2247Pregnancies and childbirth in women with arrhythmogenic right ventricular cardiomyopathy are associated with low risk of ventricular arrhythmias

Background

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is associated with a risk of ventricular arrhythmias (VA) and sudden cardiac death (SCD). Even though female patients with ARVC are considered to be at lower risk of VA, the impact of pregnancy and child birth on the arrhythmic risk and development of arrhythmic substrate in the context of ARVC remains insufficiently studied.

Objective

To assess the risk of VA in relation to childbirth in women with ARVC and the impact of multiple pregnancies on progression of arrhythmic manifestations of the disease.

Methods

The study included 186 females with definite ARVC (n=107, 70 probands) or unaffected mutation-carriers (n=79) with median age at the end of follow up of 48 (IQR 34–60) years. Seventeen women had 1, 59 had 2 and 29 had ≥3 child births by the age of 40 years. VA was defined as ventricular tachycardia, appropriate ICD therapy, aborted cardiac arrest or SCD. Proportions of patients who experienced VA by the age of 40 years were compared between nulliparous women (n=81) and those with reported child births (n=105). VA-free survival after accomplished pregnancies was assessed for women ≥40 years of age (n=119). Cumulative probability of VA for each pregnancy (n=230) was assessed from conception through 2 years after child birth and compared between those that occurred before ARVC diagnosis (Pre-Ds, n=164), after it (Post-Ds, n=11) and in unaffected mutation carriers (No-Ds, n=55).

Results

The nulliparous women had lower age at ARVC diagnosis (37 vs 44, p=0.023) and more often had VA before the age of 40 (31% vs 13%, p=0.003) while the number of child births was not related to the prevalence of VA (18% among women with 1 childbirth, 12% in those with 2 and 14% in those with 3 or more, ns). Three women suffered SCD before the age of 40. VA-free survival after 40 years did not differ between nulliparous and those who gave birth (Figure A). Only four pregnancy-related events were documented (Figure B): 1 in the Post-Ds group and three in the Pre-Ds group. No pregnancy-related events were reported in the unaffected mutation carriers.

Conclusion

In this Scandinavian cohort of women with ARVC we observed no indication of an increased VA risk either associated with pregnancies or during long-term follow up after the last child birth.

P992Incidence, predictors, and success of ventricular tachycardia catheter ablation in arrhythmogenic right ventricular cardiomyopathy (ARVC): A long-term cohort study from the Nordic ARVC registry

Background

Catheter ablation may reduce ventricular tachycardia (VT) burden in arrhythmogenic right ventricular cardiomyopathy (ARVC) patients. However, little is known about factors predicting need for ablation and various outcomes have been reported.

Purpose

We sought to investigate predictors and use of VT ablation and to evaluate the post-procedural outcome in ARVC patients.

Methods

We studied 435 patients from the Nordic ARVC registry including 220 probands with definite ARVC according to the 2010 task force criteria and 215 mutation-carrying relatives identified through cascade screening. Patients were followed until first-time VT ablation, death, heart transplantation, or January 1st 2018. Additionally, patients undergoing VT ablation were further followed from the time of ablation for recurrent ventricular arrhythmias.

Results

Cumulative use of VT ablation was 4% (95% CI 3%-6%) and 11% (95% CI 8%-15%) after 1 and 10 years. All procedures were performed in probands in whom the cumulative use was 8% (95% CI 5%-12%) and 20% (95% CI 15%-26%). In adjusted analyses restricted to probands, only young age predicted need for ablation. In patients undergoing ablation, risk of recurrent arrhythmias was 59% (95% CI 44%-71%) and 74% (95% CI 59%-84%) 1 and 5 years after the procedure. Despite high recurrence rates, the burden of ventricular arrhythmias was reduced after ablation (p=0.0042). Young age, use of several antiarrhythmic drugs and inducibility to VT immediately after ablation were associated with an unfavorable outcome.

Conclusions

Twenty percent of ARVC probands developed a clinical indication for VT ablation within 10 years after diagnosis whereas mutation-carrying relatives were without such need. Although the burden of ventricular arrhythmias decreased after ablation, risk of recurrence was substantial.

Hospitalized acute patients with fever and severe infection have lower mortality than patients with hypo- or normothermia: a follow-up study

OBJECTIVES

Severe infection is a frequent cause of admission to an acute medical unit (AMU). However, not all infected patients present with fever. The aim was to assess differences in 30-day mortality among patients hospitalized with community-acquired severe infection presenting with hypothermia, normothermia or fever.

METHODS

A retrospective single-center follow-up at an AMU from August 1, 2009 to August 31, 2011. Patients were included the first time they presented with severe infection within the study period. Temperature was categorized into hypothermia (<36.0ºC), normothermia (36.0ºC-38.0ºC) and fever (>38.0ºC). Severe infection was defined as a discharge diagnosis indicating infection combined with organ failure within the first 24 h after arrival. Multivariable Cox regression analysis was computed to assess the association between temperature and 30-day mortality.

RESULTS

A total of 2128 patients with severe infection were included. 3.0% (N  =  64) were hypothermic, 57.1% (N  =  1216) normothermic and 39.9% (N  =  848) had fever at arrival. Crude 30-day mortality was 16.1% (N  =  342, 95%CI 14.5-17.7%); 37.5% (N  =  24, 95% CI 25.7-50.5%) for hypothermic patients, 18.3% (N  =  223, 95%CI 16.2-20.6%) for normothermic patients and 11.2% (N = 95, 95%CI 9.2-13.5%) for patients with fever. Compared to normothermic patients, the adjusted hazard ratio of 30-day mortality among hypothermic patients was 1.62 (95%CI 1.06-2.49) and 0.74 (95%CI 0.58-0.94) among patients with fever.

CONCLUSIONS

Over half of the patients admitted to an AMU with severe infection were normothermic at arrival. Hypothermia was associated with an increased risk of short-term mortality, whereas patients with fever were associated with a lower risk compared to those with normothermia.

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.

Hyponatremia as a prognostic and predictive factor in metastatic renal cell carcinoma

Background:

Low serum sodium has recently been associated with poor survival in localised renal cell carcinoma (RCC). We now show the prognostic effect of serum sodium in patients with metastatic RCC (mRCC).

Methods:

Cohort A comprised 120 consecutive patients with mRCC receiving subcutaneous, low-dose interleukin-2 and interferon-α. Hyponatremia was assessed in univariate and multivariate analyses. An independent cohort of another 120 patients with mRCC was used for validation (cohort B).

Results:

In cohort A, estimated 5-year survival was 15% and median survival was 15.1 months. Serum sodium ranged between 126 and 144 mM. Twenty-four patients (20%) had serum sodium levels below normal range (<136 mM). In multivariate analysis, significant independent risk factors for short survival were low serum sodium (P=0.014), high neutrophils (P=0.018), lactate dehydrogenase >1.5 upper normal level (P=0.002), and number of metastatic sites (+3) (P=0.003). In cohort B, serum sodium ranged between 128 and 146 mM. Seventeen patients (14%) had sodium levels below normal range. In multivariate analysis, serum sodium was validated as an independent prognostic factor (P=0.001). A significant association between lack of response and hyponatremia was observed in both cohorts (P=0.003 and P=0.02, respectively).

Conclusion:

Low serum sodium is a new, validated, independent prognostic, and predictive factor in patients with mRCC.

Serum-sodium as an independent prognostic factor in metastatic renal cell carcinoma

5102

Background: Recently, low serum sodium has been associated with poor disease-free and overall survival in localized renal cell carcinoma (RCC) (Vasudev, Clin Can Res. 2008). The present study investigated the prognostic impact of serum-sodium values below normal in patients with metastatic RCC (mRCC). Methods: A cohort of 120 consecutive patients with mRCC received subcutaneous, low-dose Interleukin-2 and Interferon-α at Dept. of Oncology, Aarhus University Hospital, from 2002 to 2004 (Cohort A). Baseline variables were collected retrospectively. Follow up was at least 4 years. Potential prognostic factors were analyzed by univariate and multivariate analyses. Endpoint was overall survival. An independent cohort of 120 consecutive patients with mRCC was used for validation. These patients were treated with interleukin-2 based regimens at the same institution from 1999 to 2002 (Cohort B). Data in this cohort were prospectively collected. Results: In cohort A, the estimated 5-year survival rate was 15% and the median survival was 15.1 months. Serum-sodium ranged between 126 and 144 mmol/l. Twenty-four patients (20%) had serum-sodium levels below normal range (<136 mmol/l). In the multivariate analysis, significant independent risk factors of short survival were serum-sodium below normal value (HR 1.90, CI 1.1–3.2, p = 0.014), high neutrophile count (>7) (HR 1.75, CI 1.1–2.8, p = 0.018), lactate dehydrogenase >1.5 upper normal level (HR 2.09, CI 1.3–3.3, p = 0.002), and number of sites (+3) (HR 1.92; CI 1.3–2.9, p = 0.003). In cohort B, the observed 5-year survival rate was 15% and the median survival was 15 months. Serum-sodium ranged between 128 mmol/l and 146 mmol/l. Seventeen patients (14%) had sodium levels below normal range. In the multivariate analysis, serum-sodium was validated as an independent prognostic factor (HR 2.98, CI 1.54–5.77, p = 0.001). Conclusions: Low serum-sodium is a new, validated, independent prognostic factor in patients with metastatic RCC.

No significant financial relationships to disclose.

Prophylactic cavotricuspid isthmus block during atrial fibrillation ablation in patients without atrial flutter: a randomised controlled trial

OBJECTIVES

This randomised trial evaluated if patients with atrial fibrillation (AF) and no history of atrial flutter (AFL) had any benefit of prophylactic cavotricuspid isthmus block (CTIB) in addition to circumferential pulmonary vein ablation (CPVA).

METHODS

149 patients with AF (54% paroxysmal) were randomised to CPVA and CTIB (group CTIB+, n = 73) or CPVA alone (group CTIB-, n = 76). Patients were followed for 12 months with repetitive 7-day Holter monitoring after 3, 6 and 12 months.

RESULTS

Six patients (4%) had cardiac tamponade, and one patient had a stroke. No difference was found in the cumulative AFL-free rate between the two treatment groups (CTIB+: 88% vs CTIB-: 84%, hazard ratio (HR) 0.80, 95% CI (0.34 to 1.90), p = 0.61). There was no difference in the cumulative AF-free rate between the groups (CTIB+: 34% vs CTIB-: 32%, HR 0.93, 95% CI (0.63 to 1.38), p = 0.71). Overall, 33% of the patients were free of AF after a single procedure. Including reprocedures, a complete or partial beneficial effect was noted in 62% of the patients at 12 months. At 12-month follow-up, 24 (50%) patients with documented AF or AFL in the Holter recordings were asymptomatic.

CONCLUSIONS

It was not possible to demonstrate any beneficial effect of CTIB in addition to CPVA with regard to AFL or AF recurrences during follow-up. Repetitive long-term Holter monitoring demonstrated a 33% rate of freedom from AF during a 1-year follow-up. Including additional CPVA procedures, a clinical effect was noted in 62% of the patients at 12 months. Patients with AF or AFL recurrences were often asymptomatic.

The platelet polymorphism PlA2 is a genetic risk factor for myocardial infarction

OBJECTIVES

Platelet glycoprotein (GP) receptor IIb/IIIa plays a key role in the development of myocardial infarction (MI), and Pl(A2) is a polymorphism in the gene encoding this receptor. The prevalence of Pl(A2) shows pronounced geographical variation and has to our knowledge not been presented for a Scandinavian population before. Platelets from Pl(A2)-positive individuals show increased aggregability compared with platelets from Pl(A2)-negative individuals, and Pl(A2) genotypes might be associated with MI. The purpose of this study was to investigate the relation between the Pl(A2) polymorphism and MI in a large Scandinavian population.

DESIGN

Case-control study. We included patients with angiographically verified CAD with and without previous MI and a group of healthy individuals matched for age, race, and sex.

RESULTS

We studied the frequency of Pl(A2) in 1191 healthy individuals and 1019 patients with coronary artery disease (CAD). Amongst these patients, 529 subjects had suffered an MI previously. Pl(A2) was present in 28% of healthy individuals, 28% of patients with CAD but no MI, and in 35% of patients with CAD and MI. The difference between healthy individuals and MI patients was significant (P = 0.002). Furthermore, a graded relationship between the number of Pl(A2) alleles and the risk of MI was seen (P = 0.011). Associations between Pl(A2) and traditional cardiovascular risk factors as well as mean platelet volume were investigated. We found a significant interaction between Pl(A2) and serum cholesterol.

CONCLUSION

In our Scandinavian study population the common platelet polymorphism Pl(A2) is significantly associated with an increased risk of MI, but not of CAD. Clinically, typing for Pl(A2) might have implications for antiplatelet therapy of patients with MI.

LDL receptor mutation genotype and vascular disease phenotype in heterozygous familial hypercholesterolaemia

Patients with homozygous familial hypercholesterolaemia (FH) caused by receptor-negative, low-density lipoprotein (LDL) receptor gene mutations have higher concentrations of LDL-cholesterol in plasma and earlier onset of cardiovascular disease (CVD) than patients homozygous for receptor-defective, LDL receptor mutations. In contrast, it is uncertain whether the severity of atherosclerotic disease differs in heterozygous FH caused by receptor-negative and receptor-defective mutations. The present authors investigated the influence of LDL receptor mutation type on the clinical phenotype in 31 patients with heterozygous FH caused by the receptor-negative, Trp23-stop mutation and in 31 patients heterozygous for the receptor defective Trp66-Gly mutation. Untreated levels of plasma LDL-cholesterol and calculated cholesterol-years score did not differ significantly between the two groups of patients. Detection of vascular disease was based on two approaches: (1) measurement of coronary calcification by spiral computed tomography (CT) scanning; and (2) ultrasonic measurement of carotid intima-media thickness (IMT). Age was significantly correlated to the presence of coronary calcification, but controlling for relevant cofactors, there was no evidence that the receptor-negative mutation caused more calcification than the receptor-defective mutation. Furthermore, carotid IMT was significantly influenced by plasma concentrations of Lp(a) and triglycerides, as well as by age, sex and smoking status, but again, there was no statistically significant effect of LDL receptor gene mutational type. The similarity in vascular phenotypes was probably caused by a similar life-long burden of LDL-cholesterol in the two groups of patients.

Impact of acute biventricular pacing on left ventricular performance and volumes in patients with severe heart failure. A tissue doppler and three-dimensional echocardiographic study

OBJECTIVES

We used tissue velocity imaging (TVI) and three-dimensional echocardiography to evaluate the effect of acute biventricular pacing on left ventricular (LV) performance and volumes in patients with severe heart failure and bundle branch block.

BACKGROUND

Biventricular pacing causes acute hemodynamic improvement in patients with severe heart failure, and QRS duration has been used as a predictor of improved resynchronization. Tissue velocity has the potential of demonstrating the degree of LV resynchronization and three-dimensional echocardiography enables accurate quantitation of LV volumes and function.

METHODS

TVI and three-dimensional echocardiography were performed during sinus rhythm and biventricular pacing in 25 consecutive patients with severe heart failure.

RESULTS

Biventricular pacing significantly improved the extent of contracting myocardium in synchrony by 15.4% and the duration of contraction synchrony by 17% (p < 0.05 for both). Furthermore, end-diastolic and end-systolic volumes decreased by 7 +/- 4.5% and 13 +/- 6% (p < 0.01) and ejection fraction increased by 22.8 +/- 9% (p < 0.01). Baseline duration of QRS and the preejection period as well as the extent of myocardium with asynchronous contraction measured by TVI predicted pacing efficacy. In multivariate analysis, only the extent of myocardium with asynchronous contraction at the LV base predicted biventricular pacing efficacy.

CONCLUSION

Biventricular pacing improves LV systolic performance and reduces LV volumes during short-term treatment. TVI provides important pathophysiological information on the degree of LV resynchronization and may contribute to improved patient selection.

Four-strand hamstring tendon autograft compared with patellar tendon-bone autograft for anterior cruciate ligament reconstruction. A randomized study with two-year follow-up

Seventy-two patients with subacute or chronic rupture of the anterior cruciate ligament were randomly assigned to autograft reconstruction with four-strand gracilis and semitendinosus tendon (N = 37) or with patellar tendon-bone (N = 35) from the ipsilateral side. The groups were similar in terms of age, sex, level of activity, degree of laxity, meniscal lesions found surgically, and rehabilitation program. The follow-up was performed at another hospital by independent observers after 6, 12, and 24 months. Sixty-one patients (32 with hamstring tendon grafts and 29 with patellar tendon grafts) complied with the follow-up routine for the full 24 months. No differences were found between the groups with respect to Cincinnati functional score, KT-1000 arthrometer measurements, or stairs hopple test results. The subjective result and the single-legged hop test result were better for the hamstring tendon group after 6 and 12 months, but no differences were found after 24 months. The hamstring tendon group showed better isokinetic knee extension strength than did the patellar tendon group after 6 months, but not after 12 and 24 months. There was a significant weakness in isokinetic knee flexion strength among the hamstring tendon group. Anterior knee pain was not significantly different between the groups, but kneeling pain was significantly less common in the hamstring tendon group after 24 months.

Incomplete thromboxane inhibition with 100 mg of intravenous acetylsalicylic acid in patients with acute ST elevation myocardial infarction: a placebo-controlled pilot trial

BACKGROUND

Acetylsalicylic acid (ASA) is now a standard treatment of acute myocardial infarction (AMI). ASA inhibits thromboxane A(2) (TXA(2)) production by blocking the constitutive cyclooxygenase (COX)-1 enzyme, but only to a small degree the inducible COX-2. COX-2 is induced by increased concentrations of cytokines, which is related to an enhanced inflammatory response. Previously, we have found a complete inhibition of TXA(2) synthesis in healthy volunteers after intravenous administration of 50 mg of ASA. We measured in a randomized, placebo-controlled pilot trial the effect of 100 mg of ASA injected intravenously on TXA(2) synthesis in AMI patients treated with streptokinase.

METHODS AND RESULTS

Nineteen patients with AMI treated with streptokinase were randomized to 100 mg of ASA or placebo injected intravenously. Se-TXB(2) and bleeding time were measured before and after drug administration. One hundred and eighty minutes after intravenous ASA administration, treatment with oral ASA was initiated. We found a significant decrease in serum concentrations of TXB(2) after 30, 60 and 180 min following ASA injection compared to placebo, but in none of the patients was complete inhibition of TXA(2) production achieved. No significant change in bleeding time could be demonstrated.

CONCLUSION

Intravenous ASA in a dosage of 100 mg did not completely prevent TXA(2) production in AMI patients treated with streptokinase. This may be due to synthesis of TXA(2) by the inducible COX-2 enzyme and/or to a transcellular metabolism in platelets of prostanoids generated by endothelial cells.

LDL-receptor gene mutations and the hypocholesterolemic response to statin therapy

Studies of the cholesterol lowering effect of statin therapy as a function of low-density lipoprotein (LDL)-receptor mutation type have not produced a clear picture, possibly because they included patients with several different kinds of LDL-receptor mutations. We studied the response to treatment with fluvastatin in 28 patients with heterozygous familial hypercholesterolemia as a result of a receptor-negative mutation (Trp23-stop) and in 30 patients with a receptor-binding defective mutation (Trp66-Gly) to test the hypothesis that response to treatment depends on the type of mutation. Patients were randomized to 12 weeks of treatment with fluvastatin 40 mg daily and 12 weeks of placebo treatment, preceded by a placebo run-in period of 8 weeks in a double-blind, cross-over design. Untreated plasma concentrations of lipids and lipoproteins were similar in the two groups of patients. Plasma cholesterol and LDL cholesterol response to therapy tended to be less marked in receptor-binding defective patients, but the differences were not statistically significant. A tabulation of the results of the present and earlier studies suggests that differences in treatment response as an apparent function of LDL-receptor gene mutational type occur mainly in populations with recent genetic admixture (<400 years). In such populations, persons with the same mutation in the LDL-receptor gene are more likely to share other but undetermined genetic variations affecting the pharmacology of statins.

Three dimensional echocardiography documents haemodynamic improvement by biventricular pacing in patients with severe heart failure

OBJECTIVES

To quantify the short term haemodynamic effects of biventricular pacing in patients with heart failure and left bundle branch block by using three dimensional echocardiography.

DESIGN

Three dimensional echocardiography was performed in 15 consecutive heart failure patients (New York Heart Association functional class III or IV) with an implanted biventricular pacing system. Six minute walk tests were performed to investigate the effect of biventricular pacing on exercise capacity. Data were acquired at sinus rhythm and after short term (2-7 days) biventricular pacing.

RESULTS

Compared with baseline values, biventricular pacing significantly reduced left ventricular end diastolic volume (EDV) by mean (SD) 4.0 (5.1)% (p < 0.01) and end systolic volume (ESV) by 5.6 (6.4)% (p < 0.02). Mitral regurgitant fraction was significantly reduced by 11 (12.1)% (p < 0.003) and forward stroke volume (FSV) increased by 13.9 (18.6)% (p < 0.02). Exercise capacity was significantly improved with biventricular pacing by 48.4 (43.3)% (p < 0.00001). Regression analyses showed that the percentage increase in FSV independently predicted percentage improvement in walking distance (r(2) = 0.73, p < 0.0002). Both basal QRS duration and QRS narrowing predicted pacing efficacy, showing a significant correlation with %DeltaEDV, %DeltaESV, and %DeltaFSV.

CONCLUSIONS

In five of 15 consecutive patients with heart failure and left bundle branch block, biventricular pacing induced a more than 15% increase in FSV, which predicted a more than 25% increase in walking distance and was accompanied by an immediate reduction in left ventricular chamber size and mitral regurgitation.

Two mutations in the same low-density lipoprotein receptor allele act in synergy to reduce receptor function in heterozygous familial hypercholesterolemia

Mutations in genes are not necessarily pathogenic. Expression of mutant genes in cells can therefore be required to demonstrate that mutations in fact disturb protein function. This applies especially to missense mutations, which cause an amino acid to be replaced by another amino acid. In the present study of two families with familial hypercholesterolemia in the heterozygous form, we found two mutations in the same allele of the low-density lipoprotein (LDL) receptor gene: a missense Asn543. His mutation (N543H) in exon 11, and an in-frame 9-bp deletion (2393del9) in exon 17. The two mutations were identified in heterozygous FH index patients in whom no other pathogenic mutations were detected by SSCP analysis of the remaining 16 exons and the promoter region. Both mutations cosegregated with hypercholesterolemia within the families. Each of these mutations had little or no effect on receptor function in transfected COS cells, but when both mutations were present simultaneously, receptor function, as assessed by flow cytometric measurement of fluorescent LDL uptake in cells, was reduced by 75%. Immunostainable receptors on the cell surface were decreased by 80% as measured by flow cytometry. The two mutations therefore acted in synergy to affect receptor function, possibly during intracellular receptor transport, since Northern blot analysis suggested that mRNA levels were unaffected. Without screening of the entire coding regions of the gene, the synergistic action of these two LDL receptor mutations would not have been detected.

Flow cytometric assessment of effects of fluvastatin on low-density lipoprotein receptor activity in stimulated T-lymphocytes from patients with heterozygous familial hypercholesterolemia

To test the effects of fluvastatin on low-density lipoprotein (LDL) receptor activity in patients with heterozygous familial hypercholesterolemia, the authors measured LDL receptor activity in stimulated T-lymphocytes prepared from 34 patients before and after treatment with 40 mg fluvastatin daily for 12 weeks. Maximally induced pretreatment LDL receptor activities did not correlate with pretreatment plasma cholesterol levels or with changes in plasma cholesterol levels during treatment, and there were no significant changes in LDL receptor activity during treatment. Barring methodological problems, two explanations are possible. Insofar that LDL receptor activity in lymphocytes reflects LDL receptor activity in the liver, the results suggest that the primary response to treatment with fluvastatin in heterozygous familial hypercholesterolemia (FH) patients is not enhanced LDL receptor activity. Alternatively, fluvastatin increases LDL receptor activity in hepatocytes but has little effect on receptor-dependent lipoprotein catabolism in extrahepatic tissues in vivo.

Association of coronary heart disease with age-adjusted aortocoronary calcification in patients with familial hypercholesterolaemia

OBJECTIVES

Existing algorithms of risk of coronary heart disease (CHD) do not pertain to patients with familial hypercholesterolaemia (FH), whose arteries have been exposed to hypercholesterolaemia since birth. We studied a cohort of FH patients to compare four diagnostic models of CHD: traditional risk factors of CHD (age, sex, cholesterol, hypertension, smoking and body mass index), cholesterol year score, and aortic as well as coronary calcium measured by spiral computed tomography (CT).

SUBJECTS

We invited 88 individuals with molecularly defined FH of whom 80 (91%) decided to participate.

RESULTS

Analysis of receiver operating characteristic curves showed that the age-adjusted coronary calcium score was more strongly associated with clinical manifestations of CHD than were traditional risk factors (P < 0.002), cholesterol year score (P << 0.0001), and the age-adjusted aortic calcium score (P < 0.0004).

CONCLUSIONS

Age-adjusted coronary calcium score shows promise as an indicator of CHD in FH patients.

[Percutaneous transluminal septal myocardial ablation in hypertrophic obstructive cardiomyopathy. A new therapeutic option]

We here report on the PTSMA results in four HOCM patients having severe symptoms despite medical treatment and dual chamber pacing. Between two and five ml of ethanol was injected in one or two septal branches from the left coronary artery. Six months after treatment the pressure gradient across the left ventricular outflow tract was reduced between 25-80 mmHg at rest and between 55-180 mmHg at exercise. There was an increase in functional capacity of about two NYHA-classes. Two patients developed permanent right bundle branch block, and one patient with pre-existing left bundle branch block developed persistent total atrioventricular block after the treatment. Serum creatine phosphokinase MB increased on average to 146 U/l. No other complications were seen. In conclusion, our initial PTSMA results seems promising.

Flow cytometric assessment of LDL ligand function for detection of heterozygous familial defective apolipoprotein B-100

BACKGROUND

Familial defective apolipoprotein (apo) B-100 (FDB) is caused by a mutation in the apoB gene and characterized by decreased binding of LDL to LDL receptors because of reduced function of the apoB-100 ligand. FDB may be associated with severe hypercholesterolemia and cannot always be distinguished from familial hypercholesterolemia phenotypically.

METHODS

We used a fluorescence flow cytometry assay with Epstein-Barr virus-transformed lymphocytes to detect reduced LDL ligand function by competitive binding with fluorescently conjugated LDL (DiI-LDL). The assay was tested and validated using LDL from patients heterozygous for the Arg(3500)-Gln mutation and their first-degree relatives. Knowing the actual apoB genotype of patients and relatives allowed us to assess the ability of the assay to predict the results of DNA analysis. The results were compared to measurements of LDL ligand function in unrelated healthy control subjects to characterize functionally the Arg(3500)-Gln mutation.

RESULTS

Fluorescence was significantly increased in cells incubated with DiI-LDL in competition with unlabeled LDL from FDB(R3500Q) heterozygotes compared with cells incubated with DiI-LDL in competition with unlabeled LDL from relatives or unrelated healthy control subjects. Thus, patients heterozygous for the Arg(3500)-Gln mutation had significantly reduced LDL ligand function. The binding affinity of LDL from FDB(R3500Q) heterozygotes was 32% of that in non-FDB relatives and healthy controls. The assay had a diagnostic sensitivity of 0.95 and diagnostic specificity of 0.89.

CONCLUSIONS

The diagnostic accuracy of the assay was too low to allow reliable diagnosis of individual cases of heterozygous FDB(R3500Q). However, fluorescence flow cytometry may supplement genetic identification of FDB and functionally characterize gene mutations associated with major reductions in LDL ligand function.

Functional characterization of two low density lipoprotein receptor gene mutations by fluorescence flow cytometric assessment of receptor activity in stimulated human T-lymphocytes

We report a functional characterization of the W23X and W66G low density lipoprotein (LDL) receptor gene mutations. The authors used two-color fluorescence flow cytometry to measure LDL receptor activity in stimulated T-lymphocytes, prepared from patients heterozygous for the W23X or W66G mutation, and compared the results with measurements of LDL receptor activity in stimulated T-lymphocytes prepared from unrelated healthy control subjects. It was found that the W23X mutation significantly reduced LDL receptor expression and LDL binding and internalization, and that the W66G mutation significantly reduced LDL receptor expression and LDL binding. LDL internalization in patients heterozygous for the W66G mutation was not significantly reduced. The data support the concepts that the W23X mutation prevents production of LDL receptors (class I) and that the W66G mutation produces LDL receptors unable to recycle normally in cells (class V).

Linking genotype to aorto-coronary atherosclerosis: a model using familial hypercholesterolemia and aorto-coronary calcification

Most studies of the pathogenesis of coronary heart disease occur between gene variants and biochemical or physiological variables known to be atherogenic. In many situations, however, the gene products are not necessarily known. We studied 17 families (n = 122) with mutations in the low density lipoprotein (LDL) receptor gene as a model in which to test formally for linkage directly between an atherogenic genotype and ischemic heart disease (IHD) or aorto-coronary calcified atherosclerosis. In each family one of three different mutations was found: the Trp66-Gly mutation, the Trp23-Stop mutation, or a ten kilobase deletion removing exons 3-6 of the LDL receptor gene. Genomic DNA was used to determine these mutations by either enzymatic cleavage assays or Southern blotting. Aorto-coronary calcification was significantly associated with age and plasma cholesterol. Sex, hypertension, BMI and smoking were not associated with aorto-coronary calcification. Nonparametric analysis indicated significant linkage of the LDL receptor gene locus to aortic (p < 0.00005) and to aorto-coronary calcified atherosclerosis (p < 0.00001). Assuming a dominant mode of inheritance, significant linkage was detected for aortic (LOD = 3.89) and aorto-coronary calcified atherosclerosis (LOD = 4.10). We suggest that the atherogenicity of variations in other genes could be assessed by a similar approach.

Normolipidemia and hypercholesterolemia in persons heterozygous for the same 1592 + 5G --> A splice site mutation in the low-density lipoprotein receptor gene

In the present study, we have characterized a unique splice donor G to A substitution in the moderately conserved + 5 position in intron 10 of the low-density lipoprotein (LDL) receptor gene. In two Danish families, carriers of the 1592 + 5G --> A mutation display a clinical phenotype ranging from healthy normocholesterolemic persons to classical heterozygous familial hypercholesterolemia (FH) patients. Reverse transcription-polymerase chain reaction (RT-PCR) of RNA from Epstein Barr virus (EBV)-transformed lymphoblasts obtained from members of both families demonstrated abnormal splicing generating two aberrant mRNAs due to either alternative splicing and skipping of exon 10 or activation of a cryptic splice site in intron 10 inserting 66 intronic base pairs. These abnormally spliced mRNAs were predicted to encode two abnormal receptor proteins containing an in-frame deletion of 75 amino acids and an insertion of 22 novel amino acids, respectively. Results obtained by immunofluorescence staining, flow cytometry, and confocal microscopy of transfected Chang and COS-7 cells expressing normal and mutant LDL receptors were compatible with nearly complete retention of the mutant proteins in the endoplasmic reticulum. Quantitative measurements of LDL receptor mRNAs from EBV-transformed lymphoblasts, however, did not reveal any significant differences in variant mRNA contents between mutation carriers in the families that could be related to degree of hypercholesterolemia.

LDL receptor mutations and ApoB mutations are not risk factors for ischemic cerebrovascular disease of the young, but lipids and lipoproteins are

BACKGROUND

The genetic background for ischemic cerebrovascular disease of the young and the role of lipids and lipoproteins as risk factors are not clear.

METHODS

We determined five LDL receptor mutations (Trp23Stop, Trp66Gly, Trp556Ser, 313+1G --> A, 1846-1G --> A) and three apolipoprotein B mutations (Arg3500Gln, Arg3500Trp, Arg3531Cys), and other risk factors for ischemic cerebrovascular disease in 80 patients (36 women, 44 men) with onset of disease before the age of 50 years compared with 3366 individuals from a general population sample within the same age range.

RESULTS

None of the patients were carriers of mutations in the LDL receptor (Trp23Stop, Trp66Gly, Trp556Ser, 313+1G --> A, 1846 - 1G --> A) or the apolipoprotein B gene (Arg3500Gln, Arg3500Trp, Arg3531Cys) associated with hypercholesterolemia. However, on univariate analysis as well as on logistic regression analysis allowing for age and gender, plasma cholesterol (OR 1.4; P < 0.0005), HDL-cholesterol (OR 0.4; P < 0.005), diabetes (OR 5.8; P < 0.0001), and hypertension (OR 3.9; P < 0.001) were significant predictors of ischemic cerebrovascular disease.

CONCLUSIONS

The five most common LDL receptor mutations in Danish patients with familial hypercholesterolemia and three mutations in the apolipoprotein B gene did not predispose to ischemic cerebrovascular disease of the young. However, cholesterol and HDL-cholesterol are important risk factors for ischemic cerebrovascular disease of the young in the present study. The elevation in cholesterol could in some patients be due to rare LDL receptor mutations not tested for, and could in other patients be multifactorial in origin.