The worldwide epidemiology of acute rheumatic fever and rheumatic heart disease

The management of subacute bacterial endocarditis superimposed on rheumatic heart disease in the immediate pre-penicillin era: the case of Pasquale Imperato

Subacute bacterial endocarditis (SBE) was invariably a fatal disease in the pre-penicillin era. The availability of sulfonamide antibiotics beginning in the mid-1930s raised hopes that they would be effective in SBE. Unfortunately, except in rare instances, they were not. This paper reviews the clinical experience with sulfonamides in the pre-penicillin period in treating patients with SBE. It presents in detail the case of Pasquale Imperato, who died from the disease at the age of 72 years on 30 November 1942. In so doing, it focuses on the medical management measures then available to treat patients with SBE and on the inevitable course of the illness once it began. Also discussed is the relationship of acute rheumatic fever and its sequela, rheumatic heart disease, to predisposing people to SBE and possible genetic factors. The well-known case of Alfred S. Reinhart, a Harvard Medical School student who died from SBE in 1931 and who kept a detailed chronicle of his disease, is also discussed and contrasted with Pasquale Imperato's case.

Prognostic value of clinical and Doppler echocardiographic findings in children and adolescents with significant rheumatic valvular disease

INTRODUCTION

The diagnosis of acute rheumatic fever (RF) is based on clinical findings. However, during the chronic phase of the disease, the clinical approach is not sufficient for the follow-up of the patients and the Doppler echocardiography is a tool for the diagnosis of cardiac involvement. Prognostic variables that influence long-term outcomes are not well known.

METHODS

462 patients with RF according to Jones criteria were studied, and followed-up from the initial attack to 13.6 ± 4.6 years. All patients underwent clinical assessment and Doppler echocardiography for the detection of heart valve involvement in the acute and chronic phases. Multivariate logistic regression analysis was used to identify the factors influencing long-term heart valve disease.

RESULTS

Carditis occurred in 55.8% and subclinical valvulitis in 35.3% patients. In the chronic phase, 33% of the patients had significant valvular heart disease. No normal Doppler echocardiography exam was observed on patients who had severe valvulitis, although heart auscultation had become normal in 13% of these. In the multivariate analysis, only the severity of carditis and the mitral and/or aortic valvulitis were associated with significant valvular heart disease. Chorea or arthritis were protective factors for significant valvular heart disease, odds ratio 0.41 (95% C.I. 0.22 - 0.77) and 0.43 (95% C.I. 0.23 - 0.82), respectively.

CONCLUSIONS

Our study suggests that the use of Doppler echocardiography during RF helps to identify prognostic factors regarding the development of significant valvular heart disease. Initial severe carditis is an important factor in the long-term prognosis of chronic RHD, whereas arthritis and chore during the initial episode of RF appears to be protective. Strict secondary prophylaxis should be mandatory in high risk patients.

Echocardiography screening for rheumatic heart disease in Ugandan schoolchildren

BACKGROUND

Historically, sub-Saharan Africa has had the highest prevalence rates of clinically detected rheumatic heart disease (RHD). Echocardiography-based screening improves detection of RHD in endemic regions. The newest screening guidelines (2006 World Health Organization/National Institutes of Health) have been tested across India and the Pacific Islands, but application in sub-Saharan Africa has, thus far, been limited to Mozambique. We used these guidelines to determine RHD prevalence in a large cohort of Ugandan school children, to identify risk factors for occult disease, and to assess the value of laboratory testing.

METHODS AND RESULTS

Auscultation and portable echocardiography were used to screen randomly selected schoolchildren, 5 to 16 years of age, in Kampala, Uganda. Disease likelihood was defined as definite, probable, or possible in accordance with the 2006 National Institutes of Health/World Health Organization guidelines. Ninety-seven percent of eligible students received screening (4869 of 5006). Among them, 130 children (2.7%) had abnormal screening echocardiograms. Of those 130, secondary evaluation showed 72 (55.4%) with possible, probable, or definite RHD; 18 (13.8%) with congenital heart disease; and 40 (30.8%) with no disease. Echocardiography detected 3 times as many cases of RHD as auscultation: 72 (1.5%) versus 23 (0.5%; P<0.001). Children with RHD were older (10.1 versus 9.3 years; P=0.002). Most cases (98%) involved only the mitral valve. Lower socioeconomic groups had more RHD (2.7% versus 1.4%; P=0.036) and more advanced disease (64% versus 26%; P<0.001). Antistreptolysin O titers were elevated in children with definite RHD.

CONCLUSIONS

This is one of the largest single-country childhood RHD prevalence studies and the first to be conducted in sub-Saharan Africa. Our data support inclusion of echocardiography in screening protocols, even in the most resource-constrained settings, and identify lower socioeconomic groups as most vulnerable. Longitudinal follow-up of children with echocardiographically diagnosed subclinical RHD is needed.

Retrospective evidence for clinical validity of expanded genetic model in warfarin dose optimization in a South Indian population

Aim: To optimize warfarin dose in patients at risk for thrombotic events, we have recently developed a pharmacogenomic algorithm, which explained 44.9% of the variability in warfarin dose requirements using age, gender, BMI, vitamin K intake, CYP2C9 (*2 and *3) and VKORC1 (*3, *4 and -1639 G>A) as predictors. The aim of the current study is to develop an expanded genetic model that can explain greater percentage of warfarin variability and that has clinical validity. Patients & methods: CYP2C9*8, CYP4F2 V433M, GGCX G8016A and thyroid status were added to an expanded genetic model (n = 243). Results: The expanded genetic model explained 61% of the variability in warfarin dose requirements, has a prediction accuracy of ±11 mg/week and can differentiate warfarin sensitive and warfarin resistant groups efficiently (areas under receiver operating characteristic curves: 0.93 and 0.998, respectively; p < 0.0001). Higher percentage of International Normalized Ratios in therapeutic range (52.68 ± 4.21 vs 43.80 ± 2.27; p = 0.04) and prolonged time in therapeutic range (61.74 ± 3.18 vs 47.75 ± 5.77; p = 0.03) were observed in subjects with a prediction accuracy of <1 mg/day compared with subjects with prediction accuracy >1 mg/day. In the warfarin-resistant group, primary hypothyroidism was found to induce more resistance while in the warfarin-sensitive group, hyperthyroidism was found to increase sensitivity. Conclusion: The expanded genetic model explains greater variability in warfarin dose requirements and it prolongs time in therapeutic range and minimizes out-of-range International Normalized Ratios. Thyroid status also influences warfarin dose adjustments.

Original submitted 21 March 2012; Revision submitted 16 April 2012

Rationale and design of a Global Rheumatic Heart Disease Registry: the REMEDY study

BACKGROUND

Rheumatic heart disease (RHD) is the principal cause of valvular heart disease-related mortality and morbidity in low- and middle-income countries. The disease predominantly affects children and young adults. It is estimated that RHD may potentially be responsible for 1.4 million deaths annually worldwide and 7.5% of all strokes occurring in developing countries. Despite the staggering global burden, there are no contemporary data documenting the presentation, clinical course, complications, and treatment practices among patients with RHD.

METHODS

The REMEDY study is a prospective, international, multicenter, hospital-based registry planned in 2 phases: the vanguard phase involving centers in Africa and India will enroll 3,000 participants with RHD over a 1-year period. We will document clinical and echocardiographic characteristics of patients at presentation. Over a 2-year follow-up, we will document disease progression and treatment practices with particular reference to adherence to secondary prophylaxis and oral anticoagulation regimens. With 3,000 patients, we will be able to reliably determine the incidence of all-cause mortality, worsening heart failure requiring hospitalization, systemic embolism (including stroke), and major bleeding individually among all participants. We will identify barriers to care in a subgroup of 500 patients.

CONCLUSION

The REMEDY study will provide comprehensive, contemporary data on patients with RHD and will help in the development of strategies to prevent and manage RHD and its complications.

Protocol for a population-based study of rheumatic heart disease prevalence and cardiovascular outcomes among schoolchildren in Nepal

INTRODUCTION

Rheumatic heart disease (RHD) remains a major contributor to morbidity and mortality in developing countries. The reported prevalence rates of RHD are highly variable and mainly attributable to differences in the sensitivity of either clinical screening to detect advanced heart disease or echocardiographic evaluation where disease is diagnosed earlier across a continuous spectrum. The clinical significance of diagnosis of subclinical RHD by echocardiographic screening and early implementation of secondary prevention has not been clearly established.

METHODS AND ANALYSIS

The authors designed a cross-sectional survey to determine the prevalence of RHD in children from private and public schools between the age of 5 and 15 years in urban and rural areas of Eastern Nepal using both cardiac auscultation and echocardiographic evaluation. Children with RHD will be treated with secondary prevention and enrolled in a prospective cohort study. The authors will compare the prevalence rates by cardiac auscultation and echocardiography, determine risk factors associated with diagnosis and progression of RHD, investigate social and economic barriers for receiving adequate cardiac care and assess clinical outcomes with regular medical surveillance as a function of stage of disease at the time of diagnosis. Prospective clinical studies investigating the impact of secondary prevention for subclinical RHD on long-term clinical outcome will be of central relevance for future health resource utilisation in developing countries.

ETHICS AND DISSEMINATION

The study was considered ethically uncritical and was given an exempt status by the ethics committee at University of Bern, Switzerland. The study has been submitted to the National Nepal Health Research Council and was registered with http://www.ClinicalTrials.gov (NCT01550068). The study findings will be reported in peer-reviewed publications. CLINICALTRIALS.GOV IDENTIFIER: NCT01550068.

Group a streptococcal diseases and their global burden

Group A streptococcus (GAS) or Streptococcus pyogenes has been recognised as an important human pathogen since early days of modern microbiology, and it remains among the top ten causes of mortality from an infectious disease. Clinical manifestations attributable to this organism are perhaps the most diverse of any single human pathogen. These encompass invasive GAS infections, with high mortality rates despite effective antimicrobials, toxin-mediated diseases including scarlet fever and streptococcal toxic shock syndrome, the autoimmune sequelae of rheumatic fever and glomerulonephritis with potential for long-term disability, and nuisance manifestations of superficial skin and pharyngeal infection, which continue to consume a sizable proportion of healthcare resources. Although an historical perspective indicates major overall reductions in GAS infection rates in the modern era, chiefly as a result of widespread improvements in socioeconomic circumstances, this pathogen remains as a leading infectious cause of global morbidity and mortality. More than 18 million people globally are estimated to suffer from serious GAS disease. This burden disproportionally affects least affluent populations, and is a major cause of illness and death among children and young adults, including pregnant women, in low-resource settings. We review GAS transmission characteristics and prevention strategies, historical and geographical trends and report on the estimated global burden disease attributable to GAS. The lack of systematic reporting makes accurate estimation of rates difficult. This highlights the need to support improved surveillance and epidemiological research in low-resource settings, in order to enable better assessment of national and global disease burdens, target control strategies appropriately and assess the success of control interventions.