Development and validation of a mobile application based on a machine learning model to aid in predicting dosage of vitamin K antagonists among Indian patients post mechanical heart valve replacement

Patients who undergo heart valve replacements with mechanical valves need to take Vitamin K Antagonists (VKA) drugs (Warfarin, Nicoumalone) which has got a very narrow therapeutic range and needs very close monitoring using PT-INR. Accessibility to physicians to titrate drugs doses is a major problem in low-middle income countries (LMIC) like India. Our work was aimed at predicting the maintenance dosage of these drugs, using the de-identified medical data collected from patients attending an INR Clinic in South India. We used artificial intelligence (AI) - machine learning to develop the algorithm. A Support Vector Machine (SVM) regression model was built to predict the maintenance dosage of warfarin, who have stable INR values between 2.0 and 4.0. We developed a simple user friendly android mobile application for patients to use the algorithm to predict the doses. The algorithm generated drug doses in 1100 patients were compared to cardiologist prescribed doses and found to have an excellent correlation.

Infective endocarditis due to Streptococci and Enterococci: A 3-year retrospective study

Introduction: Infective endocarditis (IE) is an infection of the heart valves with an aggregation of bacteria in a fibrin plaque called vegetation. Aims and Objectives: This is a retrospective study of all infective endocarditis cases due to alpha haemolytic streptococci and enterococci. Methods: All cases of infective endocarditis cases due to alpha haemolytic streptococci and enterococci in a period of three years from 1st January 2010 to 31st December 2012 were included. Isolation of the same organism from more than one set of blood cultures was taken as a confirmed case of infective endocarditis. Clinical and serological parameters were recorded using a proforma. Results: Native valve endocarditis was more common with only five prosthetic valves being involved. Out of 89 clinically suspected cases of IE in the three years from Jan 2010 to Dec 2012, for which blood was sent for culture, 63(70.78%) samples were positive by culture. Of these, 42/63(66.66%) were due to alpha-lytic Streptococci, enterococci and rare gram positive cocci. The rare ones included Enterococcus gallinarum, abiotropha defective, Vagococcus fluvialis and Nutritionally Variant Streptococci(NVS). High level Aminoglycoside resistance(HLAR) was also encountered. The varied and important features of these isolates are discussed. Complications and treatment are described. Conclusion: From a clinical microbiology point of view, the major challenge faced by the microbiologist in diagnosis of IE is proper aseptic collection of sample before starting antibiotics with a need for multiple samples to detect and also to prove the causative organism. Sensitivity reporting can be a difficult task in the context of NVS, HLAR and gram positives that are slow growing. Congestive failure and embolisation occurs even when the antibiotic treatment is successful.When patients go in for complications, it is very rarely due to wrong antibiotics.

Management protocols for chronic heart failure in India

Heart failure is a common clinical syndrome and a global health priority. The burden of heart failure is increasing at an alarming rate worldwide as well as in India. Heart failure not only increases the risk of mortality, morbidity and worsens the patient’s quality of life, but also puts a huge burden on the overall healthcare system. The management of heart failure has evolved over the years with the advent of new drugs and devices. This document has been developed with an objective to provide standard management guidance and simple heart failure algorithms to aid Indian clinicians in their daily practice. It would also inform the clinicians on the latest evidence in heart failure and provide guidance to recognize and diagnose chronic heart failure early and optimize management.

Clasificación funcional de la hipertensión pulmonar en niños: informe del task force pediátrico del Pulmonary Vascular Research Institute (PVRI), Panamá 2011 / Functional classification of pulmonary hypertension in children: Report from the PVRI pediatric taskforce, Panama 2011

Los miembros del Task Force pediátrico del Pulmonary Vascular Research Institute (PVRI, su sigla en Inglés) fueron conscientes de la necesidad de desarrollar una clasificación funcional de la hipertensión pulmonar en niños. La clasificación que se propone sigue el mismo patrón y utiliza los mismos criterios de la clasificación de la hipertensión pulmonar específica para adultos de Dana Point. Fue necesario incluir modificaciones para los niños, teniendo en cuenta que la edad, el crecimiento físico y la madurez influyen en la expresión funcional de la enfermedad. Es necesario definir el estado clínico del niño, pues ello facilita revisar la evolución del mismo en una forma consistente y objetiva a medida que él/ella crecen. Particularmente en los niños más jóvenes, se trató de incluir indicadores objetivos como el crecimiento, la necesidad de alimentos suplementarios y los registros de asistencia al colegio y a la guardería. Esto ayuda a monitorear la evolución clínica y la respuesta al tratamiento a través de los años y facilita el desarrollo de algoritmos de tratamiento en estos pacientes. Se presenta un artículo de consenso sobre una clasificación aplicable a los niños con hipertensión pulmonar que se discutió en la reunión anual del PVRI que se llevó a cabo en Panamá en febrero de 2011.

The members of the Pediatric Task Force of the Pulmonary Vascular Research Institute (PVRI) were aware of the need to develop a functional classification of pulmonary hypertension in children. The proposed classification follows the same pattern and uses the same criteria as the Dana Point pulmonary hypertension specific classification for adults. Modifications were necessary for children, since age, physical growth and maturation influences the way in which the functional effects of a disease are expressed. It is essential to encapsulate a child's clinical status, to make it possible to review progress with time as he/she grows up, as consistently and as objectively as possible. Particularly in younger children we sought to include objective indicators such as thriving, need for supplemental feeds and the record of school or nursery attendance. This helps monitor the clinical course of events and response to treatment over the years. It also facilitates the development of treatment algorithms for children. We present a consensus paper on a functional classification system for children with pulmonary hypertension, discussed at the Annual Meeting of the PVRI in Panama City, February 2011.

Consenso sobre la clasificación de la enfermedad vascular pulmonar hipertensiva en niños: reporte del task force pediátrico del Pulmonary Vascular Research Institute (PVRI) Panamá 2011 / A consensus approach to the classification of pediatric pulmonary hypertensive vascular disease: Report from the PVRI Pediatric Taskforce, Panama 2011

Las clasificaciones actuales de la hipertensión pulmonar han contribuido significativamente al conocimiento de la enfermedad vascular pulmonar, han facilitado ensayos farmacológicos y han mejorado nuestro conocimiento de las cardiopatías congénitas del adulto; sin embargo estas clasificaciones no son aplicables completamente a la enfermedad en el niño. La clasificación que aquí se propone se basa principalmente en la práctica clínica. Los objetivos específicos de esta nueva clasificación son mejorar las estrategias diagnósticas, promover la investigación clínica, mejorar nuestro conocimiento de la patogénesis, de la fisiología y de la epidemiología de la enfermedad y orientar el desarrollo de modelos de la enfermedad humana en el laboratorio y estudios en animales; también puede servir como un recurso docente. Se hace énfasis en los conceptos de maladaptación perinatal, alteraciones del desarrollo e hipoplasia pulmonar como factores causantes de la hipertensión pulmonar pediátrica; así mismo, en la importancia de los múltiples síndromes malformativos congénitos, genéticos y cromosómicos en la presentación de la hipertensión pulmonar pediátrica. La enfermedad vascular pulmonar hipertensiva en niños se divide en diez grandes categorías.

Current classifications of pulmonary hypertension have contributed a great deal to our understanding of pulmonary vascular disease, facilitated drug trials, and improved our understanding of congenital heart disease in adult survivors. However, these classifications are not applicable readily to pediatric disease. The classification system that we propose is based firmly in clinical practice. The specific aims of this new system are to improve diagnostic strategies, to promote appropriate clinical investigation, to improve our understanding of disease pathogenesis, physiology and epidemiology, and to guide the development of human disease models in laboratory and animal studies. It should be also an educational resource. We emphasize the concepts of perinatal maladaptation, maldevelopment and pulmonary hypoplasia as causative factors in pediatric pulmonary hypertension. We highlight the importance of genetic, chromosomal and multiple congenital malformation syndromes in the presentation of pediatric pulmonary hypertension. We divide pediatric pulmonary hypertensive vascular disease into 10 broad categories.

Catastrophic health expenditure & coping strategies associated with acute coronary syndrome in Kerala, India.

Background & objectives: India contributes a significant number of deaths attributed to coronary artery disease (CAD) compared to the rest of the world. Data on catastrophic health expenditure (CHE) related to acute coronary syndrome (ACS), the major cause of deaths in CAD, are limited in the literature. We estimated the magnitude of CHE and studied the strategies used to cope with CHE. Methods: Two hundred and ten ACS patients (mean age 56 yr, 83% men) were randomly selected proportionately from six hospitals in Thiruvananthapuram district, Kerala, India. Information on demographics, ACS-related out-of-pocket expenditure and coping strategies was collected using a pre-tested structured interview schedule. CHE, defined as ACS-related expenditures exceeding 40 per cent of a household's capacity to pay, was estimated using the World Health Organization methods. Health security was defined as protection against out-of-pocket expenditure through an employer or government provided social security scheme. Socio-demographic variables, effect on participants’ employment, loans or asset sales for treatment purposes, health security coverage and type of treatment were considered as potential correlates of CHE. Multiple logistic regression analyses were conducted to identify the correlates of CHE. Results: CHE was experienced by 84 per cent (95% CI: 79.04, 88.96) of participants as a consequence of treating ACS. Participants belonging to low socio-economic status (SES) were 15 times (odds ratio (OR): 14.51, 95% CI: 1.69-124.41), whose jobs were adversely affected were seven times (OR: 7.21, CI: 1.54-33.80), who had no health security were six times (OR: 6.00, CI: 2.02-17.81) and who underwent any intervention were three times (OR: 3.24, CI: 1.03-10.16) more likely to have CHE compared to their counterparts. The coping strategies adopted by the participants were loans (41%), savings (14%), health insurance (8%) and a combination of the above (37%). Interpretation & conclusions: Our findings show that viable financing mechanism for treating ACS is warranted to prevent CHE particularly among low SES participants, those having no health security, requiring intervention procedures and those with adversely affected employment.

Long-term outcome of patients operated for large ventricular septal defects with increased pulmonary vascular resistance.

BACKGROUND: There is a paucity of data regarding the long-term outcome of patients operated for ventricular septal defect with severe pulmonary arterial hypertension and elevated pulmonary vascular resistance. METHODS AND RESULTS: We evaluated the long-term follow-up results of a selected cohort of patients with nonrestrictive ventricular septal defect and elevated pulmonary vascular resistance (>6 Wood units). Thirty-eight patients, median age 7.5 years (range 6 months-27 years), with nonrestrictive ventricular septal defect with severe pulmonary hypertension were operated between 1985 and 1996 at our institute. Preoperative pulmonary vascular resistance, ratio of pulmonary blood flow to systemic blood flow, and ratio of pulmonary vascular resistance to systemic vascular resistance were 7.63+/-1.8 Wood units, 1.9+/-0.48, and 0.41+/-0.12, respectively. The majority (68.4%) had perimembranous ventricular septal defect. Thirty patients (79%) had a good outcome and were asymptomatic at a mean follow-up of 8.7 years, with significant reduction in pulmonary artery pressures. Eight patients (21%) had a poor outcome, which included 5 immediate postoperative deaths, 1 late death and 2 surviving patients with persistent severe pulmonary arterial hypertension. There was no significant difference regarding hemodynamic parameters at baseline between those who had a good outcome and those who did not. Eleven patients with a preoperative pulmonary blood flow to systemic blood flow ratio of <2:1. who had a good outcome following surgery, underwent repeat catheterization at follow-up. There was a significant reduction in their mean pulmonary vascular resistance (8.03+/-1.4 v. 4.16+/-1.6 Wood units, p=0.001) and pulmonary vascular resistance to systemic vascular resistance ratio (0.41+/-0.12 v. 0.19+/-0.06, p=0.05). CONCLUSIONS: The late results of surgery on this selected group of patients with nonrestrictive ventricular septal defect with high pulmonary vascular resistance are encouraging. Operative correction of the ventricular septal defect should be actively considered in all children presenting with nonrestrictive ventricular septal defect with a significant left-to-right shunt, despite moderately elevated pulmonary vascular resistance. Even among older patients with ventricular septal defect and moderately elevated pulmonary vascular resistance, there is a specific group that does well after operation.

Supravalvar aortic stenosis: clinical and hemodynamic profile, and surgical outcome.

BACKGROUND: Supravalvar aortic stenosis is the rarest of left ventricular outflow obstructions. Data on this rare entity from India are scarce. METHODS AND RESULTS: We retrospectively analyzed the data of 15 patients (13 males, mean age 15.5+/-10.18 years) with a diagnosis of supravalvar aortic stenosis confirmed by cardiac catheterization. Five patients had morphological features of Williams' syndrome. One patient had diffuse while the rest had discrete type of supravalvar aortic stenosis. Five patients did not have any associated lesions. A 9-year-old male had an ascending aortic aneurysm, and 3 patients had associated peripheral pulmonary artery stenosis. One child had a subaortic ventricular septal defect, and another had severe mitral regurgitation. Twelve patients had electrocardiographic evidence of left ventricular hypertrophy. Three patients had mild aortic valvar stenosis while 2 had aortic regurgitation. Six patients had dilated coronary arteries. Two patients with supravalvar aortic gradients of 20 and 40 mmHg were kept on close follow-up. One patient was not willing to undergo surgery while the other is awaiting surgery. Eleven patients underwent surgical correction. Dacron or pericardial patch aortoplasty was done in all the patients. In addition, one patient each underwent pulmonary artery plasty, ventricular septal defect closure, repair of ascending aortic aneurysm, and mitral valve replacement. The patient with diffuse type of supravalvar aortic stenosis underwent augmentation aortoplasty. Two patients died perioperatively. One was lost to follow-up. Two had moderate residual gradients. The rest of the patients were in New York Heart Association functional class I on follow-up of 6.3+/-4.7 years. CONCLUSIONS: Repair of supravalvar aortic stenosis by single sinus aortoplasty is safe and produces good results.

Congenital coronary anomalies of origin and distribution in adults: a coronary arteriographic study.

BACKGROUND: Coronary anomalies should be recognized to avoid problems during coronary intervention and cardiac surgery. METHODS AND RESULTS: We retrospectively reviewed 7400 coronary angiograms to find out the pattern and incidence of coronary anomalies of origin and distribution. We excluded patients with congenital heart diseases, coronary artery fistulae and patients with separate origin of the conus artery. and found 34 cases (0.46%) (22 males), mean age 50.7 +/- 12 years with coronary anomalies. Six cases underwent angiography prior to valve replacement and the rest were part of the evaluation for atherosclerotic coronary artery disease. The most common anomaly was separate origins of the left anterior descending coronary artery and left circumflex coronary artery [n=12 (35.3%)]. The next most common anomalies were origins of the right coronary artery from the left coronary sinus [n=7 (20.6%)] and left circumflex artery from the right sinus [n=6 (20%)]. A single coronary artery was seen in 3 cases (8.8%) which included one case of postmyocardial infarction ventricular septal rupture with triple-vessel disease, and another with two small coronary fistulae. One case each of the following coronary anomalies was found: (i) double right coronary artery, (ii) left anterior descending coronary artery from the right coronary sinus, (iii) all three coronary arteries originating separately from the right sinus, and (iv) left main coronary artery from the right sinus. Of these 34 patients, 11 (32.4%) had significant atherosclerotic disease in the anomalous vessel. CONCLUSIONS: The incidence of primary coronary anomaly seems to be less than that in earlier reports, but the pattern of anomalies appears to be similar.

Left ventricular thrombi in the presence of normal left ventricular function.

We report two cases of left ventricular thrombi identified by routine echocardiography in the presence of normal ventricular function to highlight the rarity and clinical significance of this condition. A 14-year-old boy, positive for anticardiolipin and antinuclear antibodies, was found to have a left ventricular thrombus. A 30-year-old male, who presented with a transient ischemic attack, was found to have hypereosinophilic syndrome and a mobile left ventricular thrombus. The thrombi disappeared in both patients after a few days of anticoagulant therapy without symptoms of embolization.

Coronary artery ectasia: angiographic, clinical profile and follow-up.

Out of 3200 coronary angiograms we reviewed, there were 144 cases of coronary ectasia--an incidence of 4.5 percent. Among these, 122 were associated with atherosclerotic coronary artery disease, i.e. coronary stenosis more than 50 percent (group A) and 22 not associated with coronary artery disease (group B). The patients in groups A and B were compared with age- and sex-matched patients (group C) (n=100) who had coronary artery disease alone without ectasia. The incidence of ectasia was not increased in patients with thoracoabdominal aortic aneurysm i.e. 2/154 (1.8%) or in patients with peripheral occlusive vascular disease i.e. 5/161 (3.1%). Ectasia was typed according to a modified version of the criteria proposed by Markis et al. Type II was the commonest, followed by type I, III and IV. Right coronary artery was the most commonly involved vessel by ectasia followed by left circumflex, left anterior descending artery and left main coronary artery. Diffuse ectasia was seen more frequently in right coronary artery and localised ectasia in left anterior descending artery. Patients in groups A and B had similar epidemiological characteristics, though more patients with ectasia alone (group B) had better left ventricular function and negative stress tests. The patients in group A had a similar incidence of previous myocardial infarction, coronary risk factor profile, treadmill exercise test status and severity of coronary artery disease when compared to group C. On a mean follow-up of 3+/-1.2 years, all the three groups had similar event rates.

Saccular coronary aneurysms: angiographic and clinical profile and follow-up of 22 cases.

Saccular coronary aneurysms are defined as aneurysms with the transverse dimension at least 1.5 times the longitudinal dimension. Out of 3,200 coronary angiograms reviewed, there were 22 patients (20 males) with saccular coronary aneurysms (totalling 25 aneurysms). The morphology of the aneurysms, the extent and severity of associated coronary lesions, the clinical profile and follow-up data of these patients were analysed. Aneurysms were located in left main coronary artery 3 (12%), left anterior descending coronary artery 13 (52%), right coronary artery 5 (20%) and left circumflex 4 (16%). There were 5 large aneurysms (> 15 mm in diameter) (1 in left main coronary artery, 2 each in right coronary artery and left anterior descending coronary artery) averaging 32 mm in size. Fifteen aneurysms had significant coronary artery stenosis located proximal to it, supporting the theory of post-stenotic dilatation as the aetiology of aneurysm formation. Two patients had associated muscle bridges distal to the aneurysm; 20 had atherosclerotic coronary artery disease and one had coronary artery ectasia. Five patients were lost to follow-up, which ranged from 1 year to 19 years (mean 5.3 +/- 4.1 years). No patient had history suggestive of rupture of the aneurysm on follow-up. Two patients had myocardial infarction in the territory of the vessel with the aneurysm. Rest of the patients were in NYHA class I/II. One large right coronary artery aneurysm was subjected to aneurysmectomy due to symptoms of tricuspid valve obstruction. One left main coronary artery aneurysm measuring 12 mm, on follow-up of 19 years increased in size to 45 mm, in addition the patient developed a right coronary artery aneurysm. Coronary risk factor profiles in the 20 patients with atherosclerotic coronary artery disease and aneurysms were similar to age- and sex-matched control population with atherosclerotic coronary artery disease without aneurysms.

Clinical and angiographic profile and follow-up of myocardial bridges: a study of 21 cases.

Myocardial bridging describes an angiographic entity, which is any degree of systolic narrowing of a coronary artery observed in at least one angiographic projection. Among the cineangiograms of 3200 patients reviewed, there were 21 cases (19 males) of myocardial bridges--incidence of 0.6 percent. Of these, seven had hypertrophic cardiomyopathy, six had atherosclerotic coronary artery disease and remaining eight had no evidence of either. All 21 patients had myocardial bridges in proximal or mid left anterior descending coronary artery. In addition, one case of hypertrophic cardiomyopathy had whole posterior descending coronary artery under a myocardial bridge. Another case of hypertrophic cardiomyopathy had a short normal segment of 5 mm inside a long myocardial bridge of 35 mm (tandem myocardial bridges). The length of the bridges varied from 10 to 35 mm (mean 24.5 +/- 4.5 mm) and diameter stenosis during systole varied from 40-90 percent (mean 70 +/- 8%). Two patients had large saccular coronary aneurysms proximal to the muscle bridge. Four of the eight patients who had neither hypertrophic cardiomyopathy nor coronary artery disease presented with acute anterior wall myocardial infarction and three of them had regional wall motion abnormality of left descending territory. Of the six patients who had coronary artery disease, one had 60 percent left descending artery lesion and two had recanalized segments proximal to the bridge. Five of the above six patients had significant stenosis of other coronary vessels. Four patients were lost to follow-up (mean period 3.4 +/- 2 years). In the coronary artery disease group, one patient underwent coronary artery bypass graft surgery for 3-vessel disease including graft to left descending artery and one developed inferior wall myocardial infarction. The patients in the hypertrophic cardiomyopathy group and "no hypertrophic cardiomyopathy-no coronary artery disease" group were free of events at last follow-up. Long-term prognosis of isolated myocardial bridges appears to be excellent. Degree of systolic narrowing or length of myocardial bridge does not correlate with event rates on follow-up.

Groenblad Strandberg syndrome--a case report.

A rare case of Groenblad Strandberg syndrome in which angioid streaks are associated with pseudoxanthoma elasticum is being reported. The pathology, clinical features, complications and treatment of angioid streaks are discussed in detail.

Auramine staining in detecting small number of bacilli in skin smears.

Auramine staining has been compared with Ziehl-Neelsen's staining of M. leprae in skin smear slide. The auramine method was found to be more sensitive than Ziehl-Neelsen's method and may be useful in detecting small number of M. leprae in skin smears. The inter-observer variance was minimal with auramine staining.

Thyroglobulin autoantibodies in leprosy.

Two hundred and five sera from lepromatous leprosy patients were tested for the presence of thyroglobulin autoantibodies using tanned red cell haemagglutination technique. Six out of 182 sera from LL patients and 5 out of 23 sera from LL patients with ENL gave a positive reaction for thyroglobulin autoantibodies.

Retrospective analysis of smear examinations from multiple sites in multi-bacillary leprosy.

A retrospective analysis was done on results of smears from six sites in untreated and treated multibacillary leprosy cases. The examination of three sites was found adequate to detect all multibacillary cases.