Human Mpox Virus Proctitis With Persistent Rectal Ulcers on Sigmoidoscopy

The 2022 Mpox outbreak has caused public health concerns worldwide. Mpox infection often manifests as papular skin lesions; other systemic complications have also been reported. We present the case of a 35-year-old man with HIV who presented with rectal pain and hematochezia and was found to have severe ulceration and exudate on sigmoidoscopy consistent with Mpox proctitis.

Association between plasma desmosine, a marker of elastin degradation, and total atherosclerotic burden measured by whole body magnetic resonance angiography

Background

Elastin degradation has been implicated in the pathophysiology of vulnerable atherosclerotic plaque. Desmosine is the cross-link component in the elastin molecule and is exclusively released from mature elastin breakdown, thus has the potential to be a physiologically relevant biomarker of atherosclerosis.

Objectives

The aim of the present study was: 1. To investigate whether patients with known cardiovascular disease (CVD) have higher elastin degradation as indicated by plasma desmosine (pDES); 2. to determine the relationship between pDES and total atherosclerotic burden.

Methods

We measured pDES by a validated stable isotope dilution LC-MS/MS method1 in a total of 146 subjects from the SUMMIT (SUrrogate markers for Micro- and Macro-vascular hard endpoints for Innovative diabetes Tools) study2. (62% male, mean age 64±8 (SD) years). This included 62 patients with prior clinical diagnosis of CVD (including coronary artery disease (CAD), cerebrovascular disease and/or lower extremity arterial disease (LEAD)), and 84 patients without a clinical diagnosis of CVD. Total atherosclerotic burden was measured by whole body magnetic resonance angiography (WB-MRA). The WB-MRA data was divided into 31 anatomical arterial segments with each segment scored according to degree of luminal narrowing: 0 = no stenosis, 1 = <50% stenosis, 2 = 51–70% stenosis, 3 = 71–99% stenosis, 4 = vessel occlusion. The segment scores were summed and from this, a standardized atheroma score (SAS) was calculated by summing each individual segment's stenosis score, and divided by the number of diagnostic segments before dividing by 4 which is the maximum potential score. Relationship between SAS and pDES levels was investigated using multiple linear regression models

Results

pDES levels were significantly greater in patients with established clinical CVD compared to patients with no CVD (CVD patients, 0.56 (0.45–0.67) ng/mL; patients with no CVD, 0.47 (0.41–0.54)ng/mL; p=0.001). Median SAS for the study population was 4 (2–10). Overall pDES levels showed a strong correlation with SAS (r=0.44, p≤0.001). Univariable analysis suggested a significant association between pDES and whole-body atheroma score as measured by SAS. (β 29.31, p<0.001). This association persisted in the multivariable regression model adjusting for traditional cardiovascular risk factors including age, gender, BMI, systolic blood pressure, diabetes, smoking status and LDL. (adjusted β 18.75, p=0.004)

Conclusion

pDES levels are elevated in patients with clinical CVD when compared to those with no clinical history of CVD. pDES is also strongly associated with global atheroma burden. Overall, these findings support the role of pDES as a potential biomarker for atherosclerosis.

Funding Acknowledgement

Type of funding sources: None.

Impact of social determinants of health on colorectal cancer screening and surveillance in the COVID reopening phase

BACKGROUND/AIMS

Procedural delays due to the coronavirus disease 2019 (COVID-19) pandemic may exacerbate disparities in colorectal cancer (CRC) preventive care. We aimed to measure racial and socioeconomic disparities in the prioritization of CRC screening or adenoma surveillance during the COVID reopening period.

METHODS

We identified CRC screening or surveillance colonoscopies performed during two time periods: (1) 9 June 2019-30 September 2019 (pre-COVID) and (2) 9 June 2020-30 September 2020 (COVID reopening). We recorded the procedure indication, patient age, sex, race/ethnicity, primary language, insurance status and zip code. Multivariable logistic regression was used to determine factors independently associated with undergoing colonoscopy in the COVID reopening era.

RESULTS

We identified 1473 colonoscopies for CRC screening or adenoma surveillance; 890 occurred in the pre-COVID period and 583 occurred in the COVID reopening period. In total 342 (38.4%) pre-COVID patients underwent adenoma surveillance and 548 (61.6%) underwent CRC screening; in the COVID reopening cohort, 257 (44.1%) underwent adenoma surveillance and 326 (55.9%) underwent CRC screening (P = 0.031). This increased proportion of surveillance procedures in the reopening cohort was statistically significant on multivariable analysis [odds ratio (OR), 1.26; 95% confidence interval (CI), 1.001-1.58]. Black patients comprised 17.4% of the pre-COVID cohort, which declined to 15.3% (P = 0.613). There was a trend toward an inverse association between reopening phase colonoscopy and Medicaid insurance compared with commercial insurance (OR, 0.71; 95% CI, 0.49-1.04). No significant associations were found between reopening phase colonoscopy and the remaining variables.

CONCLUSIONS

During the COVID reopening period, colonoscopies for CRC fell by over one-third with significantly more surveillance than screening procedures. Nonwhite patients and non-English speakers comprised a shrinking proportion in the COVID reopening period.

Plasma desmosine as a biomarker in acute aortic syndrome

Introduction

Acute aortic syndromes (AAS) include aortic dissection, intramural haematoma and penetrating aortic ulcer, all of which are caused by aortic wall failure and associated with significant mortality. Although, treatment options currently include early surgical intervention or aggressive medical management, disease progression and devastating complications remain commonplace. Early diagnosis of AAS as well as ability to predict those at the highest risk of disease progression would represent significant progress in the care these patients receive. Desmosine is the cross-link component in the elastin molecule and is exclusively released from mature elastin breakdown, thus is a physiologically relevant biomarker of aortic elastin degradation. The aim of the study was to test the hypothesis that plasma desmosine (pDES) concentrations are elevated in AAS and has prognostic value in indentifying those at risk of significant disease progression.

Method

Patients over 25 years old with radiologically confirmed acute aortic syndrome were recruited as part of a prospective observational study (NCT03647566). Demographic details, AAS sub-category, time from index acute aortic syndrome event and pDES concentrations measured by stable isotope dilution LC-MS/MS were recorded at baseline. Baseline and follow up maximal aortic diameters were measured on contrast-enhanced computed tomography (CT) and change in aortic diameter over time was calculated. Control plasma desmosine samples were obtained at a 2:1 ratio control subjects participating in the United Kingdom Aneurysm Growth Study. Data presented as mean±standard deviation or median [interquartile range].

Results

Plasma desmosine concentrations were measured in 53 patients (64 [53 to 71] years) with acute aortic syndromes and 106 control subjects (53 [44 to 60] years). In patients with AAS, pDES concentrations were almost twice those of control subjects (0.58±0.26 vs 0.27±0.07, p<0.001). In those with AAS, plasma desmosine concentrations were seen to be highest at presentation, and reduced over time from the aortic syndrome event (R=0.51, p=0.003). Plasma desmosine concentration was the only variable associated with increasing aortic diameter over time (R=0.34, p=0.014).

Conclusion

Plasma desmosine concentrations are elevated in patients with AAS, peak at the time of presentation and represents a promising biomarker for early identification and risk stratification in patients with AAS.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): British Heart FoundationTenovus Scotland Major Research GrantChief Scientist Office Catalytic Grant Plasma desmosine, time and expansionBaseline characteristics

Exaggerated elastin turnover in childhood and adolescence in Marfan syndrome – correlation with age – new insights from the AIMS trial

Background

Marfan syndrome (MFS) is an autosomal dominant connective tissue disorder caused by mutations in the Fibrillin1 gene (FBN1) that leads to impaired elastin formation and extra-cellular matrix homeostasis. Elastin synthesis and related lamellae formation in the aorta is completed in the newborn. Thereafter further elastin turnover is thought to be minimal during life. Elastin homeostasis is little studied in patients with MFS who have been reported to have reduced elastin in their aorta and are at risk of aortic dilatation and consequent life-threatening dissection. It is not clear if elastin loss is due to reduced elastin formation in utero or accelerated degradation during life. However, aortopathy develops early in MFS with 70% of patients developing aortic dilatation by the age of 20 years. Therefore, the longitudinal and circumferential aortic growth that occurs in childhood may involve elastic lamellae remodelling that is impaired in MFS. Desmosine is the cross-link component in the elastin molecule and is exclusively released from mature elastin breakdown, thus is a physiologically relevant biomarker of elastin turnover. We hypothesise that physiologic aortic growth is associated with elastic lamellae remodelling and increased elastin turnover, detected by elevated plasma desmosine (pDES), and that elastin turnover is exaggerated during the fast-growing period in MFS.

Purpose

The aims of this study were 1. To investigate the relationship between elastin turnover and age in the control subjects, and 2. To compare the elastin turnover in MFS with control subjects.

Methods

pDES was measured by stable isotope dilution LC-MS/MS in 113 MFS subjects (48% male, mean age 18.2±9.4 (SD) years), mean aortic root 33.8±2.1mm and Z-score 3.4±2.1 in the AIMS trial at baseline before intervention, and in 109 healthy controls (46% male, mean age 26.1±9.5 years).

Results

pDES levels were associated positively with age, body surface area and negatively with diastolic BP in the control group (p=0.05 and 0.21 respectively after correcting for age). In MFS subjects pDES also positively correlated with age and male sex (p<0.05). Interestingly, the age-dependent association with pDES showed a peak distribution in both control and MFS groups (Figure 1) where teenage children expressed the highest pDES levels. MFS subjects had significantly higher pDES compared to controls before the age of 20 (p=0.01) but in adulthood, there was no difference (Figure 2).

Conclusion

Elastin turnover is highly dynamic before early adulthood, and peaks in adolescence and is exaggerated in MFS, suggesting that this period of growth is critical in developing aortopathy.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): British Heart FoundationTENOVUS Scotland Figure 1Figure 2

Probiotic Use in Celiac Disease: Results from a National Survey

BACKGROUND AND AIMS

Patients with celiac disease (CD) commonly use supplements for perceived health benefits despite scant evidence. We aimed to characterize the prevalence and predictors of probiotic use among CD patients.

METHODS

We analyzed data from iCureCeliac®; a patient-powered research network questionnaire distributed by the Celiac Disease Foundation. We included adults with self-reported CD who answered questions regarding demographics, diagnosis, symptoms, and treatment. We compared probiotic users versus probiotic non-users and subsequently performed multivariable logistic regression, assessing for independent predictors of probiotic use.

RESULTS

4,909 patients met the criteria for inclusion in the study. Of these, 1,160 (23.6%) responded to a question regarding probiotic use. The mean age of participants was 38.8 years and 82% were female. 381 patients (33%) reported using probiotics. More probiotic users sought nutritional counseling at time of diagnosis (36% vs. 30%, p=0.05) and remained symptomatic despite a gluten-free diet (40% vs. 25%, p <0.001). Probiotic users had lower scores on the pain subscale of the SF36 (63.7±21.6 vs. 69.5±22.1, p=0.006). On multivariable analysis, patients diagnosed after age 50 (OR=2.04, 95%CI: 1.37-3.04), and those with persistent symptoms despite a gluten-free diet (OR=1.94, 95%CI: 1.44-2.63) were more likely to use probiotics.

CONCLUSION

In this large study of a national CD registry, roughly one-third of CD patients reported using probiotics. Patients diagnosed later in life were more likely to use probiotics and those who remained symptomatic despite a gluten-free diet were twice as likely to take probiotics. Patients may be seeking additional means of treatment for persistent symptoms.

P6505Urinary desmosine, an elastin-specific degradation product is associated with maximum aortic root size and aortic z-scores in patients with bicuspid aortic valve

Background

Bicuspid aortic valve (BAV) is the commonest congenital cardiac abnormality affecting up to 2% of the general population. BAV is highly diverse in phenotype however a common feature is its inherent risk of morbidity and mortality from aortic root dilatation and dissection. Aortic dilatation involves elastin degradation and desmosine is an amino acid cross-link that is released into the bloodstream and urine following elastin degradation. It is known from an earlier pilot study (DESMA) of desmosine in Marfan Syndrome (MFS) patients that plasma desmosine among patients with MFS is significantly elevated and correlates with aortic size however whether this same observation is seen in other forms of inherited aortopathies such as BAV is unclear.

Objectives

1. To investigate whether patients with BAV have higher elastin degradation as indicated by plasma desmosine and urinary desmosine levels.

2. To explore the relationship between plasma and urinary desmosine levels with aortic root size in patients with BAV.

Methods

We measured urinary (ng/mg creatinine) and plasma desmosine (ng/mL) in 20 patients with BAV and healthy control subjects using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Aortic root size and corresponding Z-scores were measured on echocardiogram. Correlation was analysed with Spearman's rank test.

Results

The patients with BAV were predominantly male (n=15, 75%) with a mean age of 50.5 years ± 17.6 [SD]. All the BAV patients had normal LV systolic function and none had prior aortic root surgery or were current smokers. Nine BAV patients had treated hypertension. Compared to controls, both plasma desmosine (0.30±0.10 vs 0.26±0.075 ng/mL, p=0.01) and urinary desmosine (15.9±4.6 vs 7.2±2.8 ng/mg creatinine, p<0.001) were significantly elevated in patients with BAV. Urinary and plasma desmosine (Figure 1) were also significantly correlated (r=0.55, p=0.01). There was a significant association between urinary desmosine and maximal aortic root size and Z-scores in the BAV cohort (Figure 2) compared to controls (p=0.02), however this was not seen with plasma desmosine.

Conclusions

Urinary and plasma desmosine levels are significantly higher in patients with BAV compared to controls. Urinary desmosine is also significantly associated with maximal aortic root size, reflecting higher elastin degradation. This suggests a potential use of desmosine as a biomarker to monitor disease progression in patients with BAV.

Acknowledgement/Funding

Anonymous Trust

Exaggerated QT prolongation after cardioversion of atrial fibrillation

OBJECTIVES

The purpose of this study was to test the hypothesis that the extent of drug-induced QT prolongation by dofetilide is greater in sinus rhythm (SR) after cardioversion compared with during atrial fibrillation (AF).

BACKGROUND

Anecdotes suggest that when action potential-prolonging antiarrhythmic drugs are used for AF, excessive QT prolongation and torsades de pointes (TdP) often occur shortly after sinus rhythm is restored.

METHODS

QT was measured in nine patients with AF who received two identical infusions of dofetilide: 1) before elective direct current cardioversion and 2) within 24 h of restoration of SR.

RESULTS

During AF, dofetilide did not prolong QT (baseline: 368 +/- 48 ms vs. drug: 391 +/- 60, p = NS) whereas during SR, QT was prolonged from 405 +/- 55 to 470 +/- 67 ms (p < 0.01). In four patients (group I), the SR dofetilide infusion was terminated early because QT prolonged to >500 ms, and one patient developed asymptomatic nonsustained TdP. The remaining five patients (group II) received the entire dose during SR. Although deltaQT was greater in group I during SR (91 +/- 22 vs. 45 +/- 25 ms, p < 0.05), plasma dofetilide concentrations during SR were similar in the two groups (2.72 +/- 0.96 vs. 2.77 +/- 0.25 ng/ml), and in AF (2.76 +/- 1.22 ng/ml). DeltaQT in SR correlated inversely with baseline SR heart rate (r = -0.69, p < 0.05), and QT dispersion developing during the infusion (r = 0.79, p < 0.01).

CONCLUSIONS

Shortly after restoration of SR, there was increased sensitivity to QT prolongation by this I(Kr)-specific blocker. Slower heart rates after cardioversion and QT dispersion during treatment appear to be important predictors of this response.

Abnormalities of the QT interval in primary disorders of autonomic failure

BACKGROUND

Experimental evidence shows that activation of the autonomic nervous system influences ventricular repolarization and, therefore, the QT interval on the ECG. To test the hypothesis that the QT interval is abnormal in autonomic dysfunction, we examined ECGs in patients with severe primary autonomic failure and in patients with congenital dopamine beta-hydroxylase (DbetaH) deficiency who are unable to synthesize norepinephrine and epinephrine.

SUBJECTS AND METHODS

Maximal QT and rate-corrected QT (QTc) intervals and adjusted QTc dispersion [(maximal QTc - minimum QTc on 12 lead ECG)/square root of the number of leads measured] were determined in blinded fashion from ECGs of 67 patients with primary autonomic failure (36 patients with multiple system atrophy [MSA], and 31 patients with pure autonomic failure [PAF]) and 17 age- and sex-matched healthy controls. ECGs of 5 patients with congenital DbetaH deficiency and 6 age- and sex-matched controls were also analyzed.

RESULTS

Patients with MSA and PAF had significantly prolonged maximum QTc intervals (492+/-58 ms(1/2) and 502+/-61 ms(1/2) [mean +/- SD]), respectively, compared with controls (450+/-18 ms(1/2), P < .05 and P < .01, respectively). A similar but not significant trend was observed for QT. QTc dispersion was also increased in MSA (40+/-20 ms(1/2), P < .05 vs controls) and PAF patients (32+/-19 ms(1/2), NS) compared with controls (21+/-5 ms(1/2)). In contrast, patients with congenital DbetaH deficiency did not have significantly different RR, QT, QTc intervals, or QTc dispersion when compared with controls.

CONCLUSIONS

Patients with primary autonomic failure who have combined parasympathetic and sympathetic failure have abnormally prolonged QT interval and increased QT dispersion. However, QT interval in patients with congenital DbetaH deficiency was not significantly different from controls. It is possible, therefore, that QT abnormalities in patients with primary autonomic failure are not solely caused by lesions of the sympathetic nervous system, and that the parasympathetic nervous system is likely to have a modulatory role in ventricular repolarization.

Diagnosing left ventricular dysfunction after myocardial infarction: the Dundee algorithm

Large-scale trials of angiotensin converting enzyme (ACE) inhibitors after acute myocardial infarction (AMI) suggest that the benefits are greatest in patients with left ventricular (LV) dysfunction. However, early evaluation of LV function in all patients after AMI by current methods can be difficult due to a lack of resources and skilled personnel. Thus a clinical algorithm that could be used at the bedside to reliably identify patients with a left ventricular ejection fraction (LVEF) < or = 40% would be helpful as an occasional alternative to echocardiography. We have devised such an algorithm based on the presence of one of: (i) clinical signs of heart failure; (ii) an index Q-wave anterior myocardial infarction; (iii) lack of thrombolytic therapy when there is a history of two or more previous myocardial infarctions and a CK rise > 1000 U/l. We tested this new algorithm prospectively in the coronary care units of two hospitals (one UK and one USA). In the UK centre, the sensitivity and specificity of the algorithm at identifying patients with a LVEF < or = 40% were 82% and 72%, respectively. In the US centre, the sensitivity of the algorithm was 91% and the specificity 78% at identifying patients with LV dysfunction. We have validated a simple clinical algorithm which can be used at the bedside for identifying patients who would benefit from an ACE inhibitor after AMI.

Normalization of acquired QT prolongation in humans by intravenous potassium

BACKGROUND

QT interval prolongation and dispersion have been implicated in serious arrhythmias in congestive heart failure (CHF) and the congenital and drug-induced long-QT syndromes (LQTS). In a subset of the congenital LQTS, infusion of potassium can correct QT abnormalities, consistent with in vitro increases in outward currents such as I(Kr) or I(Kl) when extracellular potassium concentration ([K+]o) is increased. Furthermore, increasing [K+]o decreases the potency of I(Kr)-blocking drugs in vitro. The purpose of this study was to test the hypothesis that increasing [K+]o corrects QT abnormalities in CHF and in subjects treated with quinidine.

METHODS AND RESULTS

KCl (maximum, 40 mEq) was infused into (1) 12 healthy subjects treated with quinidine sulfate (5 doses of 300 mg/5 h) or placebo and (2) 8 CHF patients and age-matched normal control subjects. Mean [K+] increased from 4 to 4.2 mEq/L to 4.7 to 5.2 mEq/L. Potassium infusion significantly reversed QTUc prolongation, especially in the precordial leads (quinidine, 590+/-79 to 479+/-35 [+/-SD] ms(1/2), P<.001; CHF, 521+/-110 to 431+/-47 ms(1/2), P<.05). There was no effect in either control group. Similarly, potassium decreased QTUc dispersion (quinidine, 210+/-62 to 130+/-75 ms(1/2), P<.01; CHF, 132+/-68 to 84+/-35 ms(1/2), P=.07) and was without effect in the control subjects. QT morphological abnormalities, including U waves and bifid T waves, were reversed by potassium.

CONCLUSIONS

Potentially arrhythmogenic QT abnormalities during quinidine treatment and in CHF can be nearly normalized by modest elevation of serum potassium.

Diagnostic value of B-type natriuretic peptide concentrations in patients with acute myocardial infarction

Although elevations of plasma atrial natriuretic peptide (ANP) concentrations have been shown to have prognostic significance in patients after acute myocardial infarction (AMI), the relation between plasma levels of B-type natriuretic peptide (BNP) and cardiovascular mortality remains unknown. To test the prognostic value of plasma ANP and BNP after AMI, plasma concentrations were measured a mean of 3 days after infarction in 75 patients. During a median follow-up of 19.7 months, 14 patients (18.4%) died of cardiovascular causes. On univariate analysis, plasma ANP and BNP, Killip class, modified Peel index, left ventricular ejection fraction, and presence of left ventricular failure were all associated with cardiovascular mortality. In contrast, plasma ANP was the only variable that correlated with the development of symptomatic heart failure and hospitalization. For the combined end point of cardiovascular mortality, symptomatic heart failure, and hospitalization, plasma neurohormones were the only variables of predictive value. By stepwise regression analysis, plasma BNP was the only significant independent predictor of cardiovascular mortality (p = 0.001), whereas plasma ANP identified patients at risk of symptomatic heart failure and hospitalization (p = 0.002 and 0.019, respectively). This study indicates that plasma BNP measured after AMI is a powerful neurohormonal predictor of subsequent cardiovascular mortality, whereas plasma ANP correlates better with the development of symptomatic heart failure and hospitalization. Routine measurement of both of these peptides in the period immediately after an AMI may provide a simple means of risk stratification with different information gained from each peptide.

Raised plasma levels of atrial natriuretic factor in cardiac allograft recipients: evidence of increased cardiac secretion and decreased renal clearance

The mechanism(s) causing high levels of plasma atrial natriuretic factor (ANF) in cardiac allograft recipients is(are) unclear. The kidney is important for the clearance of ANF and renal function may decline with cyclosporin A therapy in these patients. The relationship between plasma ANF level and renal function and also the pharmacokinetics of a continuous infusion of ANF (15.5 ng.kg-1.min-1 for 60 min) was examined in 6 cardiac allograft recipients on cyclosporin A therapy. Resting plasma ANF levels were significantly higher in these patients than in 8 healthy subjects (71 vs. 21 ng.l-1). Both effective renal plasma flow (ERPF) and glomerular filtration rate (GFR) were significantly lower in these patients than in healthy subjects (215 vs. 617 ml.min-1 and 55 vs. 102 ml.min-1 respectively). There was a significant inverse correlation between plasma ANF and ERPF (r = -0.86) and between plasma ANF and GFR (r = -0.81). During the period of ANF infusion, steady state plasma ANF levels were significantly higher in cardiac allograft recipients. Total body clearance of ANF was marginally lower in these patients than in healthy subjects (60 vs. 10.0 l.min-1) although this difference did not reach statistical significance. Derived endogenous secretion rate of ANF was threefold higher in patients when compared to healthy subjects (633 vs. 208 ng.min-1). We have therefore shown that cardiac allograft recipients on cyclosporin A have elevated plasma ANF levels and also decreased renal function. Pharmacokinetic analysis have shown that this increase in plasma ANF levels is due more to increased ANF secretion than to decreased ANF clearance in these patients.

Detection of left ventricular dysfunction after acute myocardial infarction: comparison of clinical, echocardiographic, and neurohormonal methods

OBJECTIVE

The SAVE study showed that captopril improves mortality in patients with left ventricular dysfunction after myocardial infarction and that this benefit occurred even in patients with no clinically overt heart failure. On the basis of this, it seems important to identify correctly which patients have left ventricular dysfunction after a myocardial infarction. The objective was to compare various methods of identifying patients with left ventricular dysfunction (left ventricular ejection fraction, LVEF, < or = 40%) after acute myocardial infarction. The methods compared were echocardiography (quantitative and qualitative visual assessment), clinical evaluation (subjective assessment and three clinical score methods), and measurement of plasma concentrations of cardiac natriuretic peptide hormones (atrial and brain natriuretic peptides, ANP and BNP).

DESIGN

Cross sectional study of left ventricular function in patients two to eight days after acute myocardial infarction.

SETTING

Coronary care unit of a teaching hospital.

PATIENTS

75 survivors of a recent myocardial infarction aged 40 to 88 with no history of cardiac failure and without cardiogenic shock at the time of entry to the study.

MAIN OUTCOME MEASURES

Sensitivities and specificities of the various methods of detecting left ventricular dysfunction were calculated by comparing them with a cross sectional echocardiographic algorithm for LVEF.

RESULTS

Clinical impression was poor at identifying LVEF < 40% (sensitivity 46%). Clinical scoring improved this figure somewhat (modified Peel index sensitivity 64%). Qualitative visual assessment echocardiography was a more sensitive method (sensitivity 82%) for detecting LVEF < 40%. Plasma BNP concentration was also a sensitive measure for detecting left ventricular dysfunction (sensitivity 84%) but plasma ANP concentration was much poorer (sensitivity 64%).

CONCLUSION

Left ventricular dysfunction is easily and reliably detected by echocardiographic measurement of LVEF and also by a quick qualitative echocardiographic assessment but is likely to be missed by clinical assessment alone. High concentrations of plasma BNP maybe another useful indicator of left ventricular dysfunction, particularly in hospitals where not all patients can be screened by echocardiography or radionuclide ventriculography after myocardial infarction.

Viable myocardium and reinjection of thallium

Images

Renal effects of low dose prazosin in patients with congestive heart failure

Activation of the sympathetic nervous system may contribute to the renal vasoconstriction and sodium retention seen in congestive heart failure. Previous studies in congestive heart failure patients employing large doses of prazosin that lowered systemic blood pressure have been generally disappointing. The renal haemodynamic and segmental tubular effects of low non-depressor doses of prazosin (0.25 mg and 0.50 mg) were examined in eight female patients with mild to moderate congestive heart failure. Segmental tubular function was assessed by the lithium clearance method. Compared to placebo, prazosin caused a significant increase in urinary sodium excretion (from 56 +/- 7 to 92 +/- 7 mumol.min-1, P < 0.01), paralleled by significant increases in fractional excretion of sodium and lithium. Glomerular filtration rate and effective renal plasma flow were not altered by prazosin. Prazosin pre-treatment did not alter any of the renal responses to frusemide treatment (mean dose 85 +/- 14 mg). This study demonstrates that low non-depressor doses of prazosin have a clear natriuretic effect in congestive heart failure patients, which is predominantly established by interference with tubular reabsorption.

The effect of intravenous saline loading on plasma levels of brain natriuretic peptide in man

OBJECTIVE

Recent evidence suggests the presence of a dual natriuretic peptide system consisting of atrial natriuretic factor (ANF) from the atrium and brain natriuretic peptide (BNP) from the ventricle. Discrete roles have been postulated for these two natriuretic peptides in the control of circulatory homeostasis. We have therefore compared the release of ANF and BNP in response to an acute saline load to explore a differential pattern of release for the two natriuretic peptides in man.

DESIGN

The effects of an acute saline infusion on plasma ANF and BNP concentrations were studied in 10 normal male volunteers.

METHODS

Subjects were studied on two study days in the semirecumbent position. An acute intravenous saline infusion (250 ml/min) of 18 ml/kg isotonic sodium chloride-potassium chloride solution was administered on one of the two study days. No infusion was administered on the other day as a control.

RESULTS

Plasma ANF concentrations increased significantly (P < 0.01) with saline loading without any detectable changes in plasma BNP concentrations up to 60 min following infusion. Heart rate and systolic and diastolic blood pressure were unchanged after saline loading.

CONCLUSIONS

We have shown that an acute intravenous saline load causes an increase in plasma ANF concentrations with no detectable increase in plasma BNP at least up to 60 min after the acute saline load in man. These results support the view that the release of ANF and BNP may be regulated differently, especially with regard to the time required for the acute release of each peptide.

A comparison of the redistribution and reinjection techniques in dipyridamole thallium tomography

The effect of the injection of additional thallium after a redistribution study and prior to a further resting study was evaluated in 21 patients with angiographically proven coronary artery disease. Using dipyridamole as the stress mechanism, the studies were carried out tomographically and the results analysed quantitatively with the Bull's-eye technique. Two patients had normal scans. Of the remaining 19, 11 patients had a perfusion defect which appeared irreversible on redistribution imaging. However, six of these patients demonstrated improved or normal uptake after the second injection of thallium. Of the eight patients with a reversible defect, two revealed considerably greater reversibility after reinjection. These results indicate that the reinjection of thallium prior to the resting study significantly (P < 0.02) improves the detection rate of ischaemia during dipyridamole thallium tomography.

Prazosin attenuates the natriuretic response to atrial natriuretic factor in man

The effect of alpha-1-adrenoceptor blockade with 0.25 mg oral prazosin on the renal response to atrial natriuretic factor (ANF) 5 pmol/kg/min was examined in eight healthy male volunteers undergoing maximal water diuresis. ANF on its own decreased mean arterial blood pressure (P less than 0.05) without altering heart rate or increasing plasma norepinephrine. ANF increased urinary sodium excretion by 130% (P less than 0.01) from baseline value with accompanying 18% decrease (P less than 0.05) in PAH clearance (ERPF) without changing inulin clearance (GFR). When compared to placebo infusion, ANF infusion caused a significant increase in fractional excretion lithium (FELi), a marker of proximal tubular function. Fractional distal delivery of sodium, another marker of proximal tubular outflow as determined by free water clearance, was also increased during ANF infusion. As expected, ANF decreased distal nephron fractional sodium reabsorption as evaluated by both the "lithium method" and by the conventional "solute-free water method." Prazosin on its own had no effect on blood pressure, renal function or hormonal parameters. When given in combination with ANF, prazosin blunted the natriuretic effect of ANF from 130% to 35% (P less than 0.01). However, prazosin pretreatment did not influence the ANF-induced fall in blood pressure or ERPF nor the ANF-induced suppression of plasma aldosterone. We have therefore found evidence to support the hypothesis that at basal levels of sympathetic tone, the natriuretic effect of ANF in man is dependent on an intact sympathetic nervous system, since sympathetic blockade by prazosin blunts its sodium excretory effects.

Effect of haemodialysis on plasma levels of brain natriuretic peptide in patients with chronic renal failure

1. Plasma human brain natriuretic peptide-like immunoreactivity (hBNP-li) was measured in ten patients with chronic renal failure before and after 4 h of haemodialysis. 2. Plasma hBNP-li was elevated in all patients before dialysis (mean +/- SEM 21.0 +/- 3.8 pmol/l) compared with healthy control subjects (1.3 +/- 0.2 pmol/l, n = 11), but showed considerable inter-patient variability. Before dialysis plasma hBNP-li bore no relationship to the serum creatinine level or to the mean blood pressure. 3. Plasma hBNP-li fell significantly (P = 0.04) during 4 h of haemodialysis. The fall in plasma hBNP-li correlated significantly with the degree of postural blood pressure drop (r2 = 0.44, P = 0.05) and with the fall in body weight (r2 = 0.64, P less than 0.01) after haemodialysis. In all patients, plasma hBNP-li at the end of treatment remained above that in healthy subjects. 4. There was no significant correlation between the fall in plasma hBNP-li and the fall in serum creatinine level, and between the fall in plasma hBNP-li and the fall in supine systolic or diastolic blood pressure, during haemodialysis. 5. We have shown that plasma hBNP-li is elevated in patients with chronic renal failure and is decreased during haemodialysis. The fact that the plasma hBNP-li was not reduced to normal by haemodialysis despite restoration to normovolaemia gives tentative support to the view that, in addition to hypervolaemia, another factor may also be responsible for the elevated plasma hBNP-li seen in these patients.

Dietary sodium loading increases plasma brain natriuretic peptide levels in man

The effect of dietary sodium loading on plasma human brain natriuretic peptide-like immunoreactivity (hBNP-li) was examined in 11 normotensive subjects aged 20-23 years. Plasma hBNP-li increased significantly with increasing dietary sodium intake, with levels of 1.33 +/- 0.17 pmol/l on day 5 of a normal-sodium diet (24-h urinary sodium excretion of 171 +/- 16 mmol) and 2.04 +/- 0.10 pmol/l (P less than 0.05, versus normal-sodium diet) on day 5 of a high-sodium diet (24-h urinary sodium excretion 503 +/- 36 mmol). Corresponding plasma atrial natriuretic factor levels were 5.6 +/- 1.7 pmol/l and 11.0 +/- 2.0 pmol/l (P less than 0.05, versus normal-sodium diet) on the normal- and high-sodium diets, respectively. These results suggest that, in addition to atrial natriuretic factor, BNP may be a new and important natriuretic peptide which regulates sodium homeostasis in man during increased sodium intake.

Gall-bladder perforation after long-term dapsone therapy

A 65-year-old man on maintenance dapsone therapy for dermatitis herpetiformis for 30 years was admitted to hospital with acute abdominal pain and vomiting. Investigations revealed a Heinz body haemolytic anaemia. Worsening symptoms prompted an emergency laparotomy that revealed a perforated gall bladder with pigmented biliary calculi. In previous reviews of the haematological abnormalities associated with dapsone therapy, life-threatening cholecystitis has not been described.