Screening for Heart Diseases in Primary School Students in Nakornsawan Province

Transcription

1 Screening for Heart Diseases in Primary School Students in Nakornsawan Province Pentip Supachokchaiwattana, MD, and Butsakorn Laijed, RN Department of Pediatrics, Sawanpracharak Hospital, Nakonsawan, Thailand Abstract Objectives: To determine the diagnostic accuracy of cardiac auscultation for heart disease screening by trained nurses and health officers in a simulated situation and to study the heart disease screening program in primary school students in Nakornsawan province. Methods: Trained nurses and health officers were assigned to do heart disease screening in a simulated situation in which the prevalence of heart disease was 40%. The heart disease screening program was conducted in primary school students in Nakornsawan province from December 2007 to April Results: In a simulated situation in which the prevalence of heart diseases was 40%, cardiac auscultation for heart disease screening by trained nurses and health officers had the following diagnostic accuracy; sensitivity 93.7%, specificity 78.8%, accuracy 84.8%, positive predictive value 74.7%, negative predictive value 95%, post test likelihood if the test was negative 5.1%, and a likelihood ratio of 4.4. There were 79,319 students from 591 primary schools in Nakornsawan province included in the heart disease screening program. 37 students were confirmed to have congenital heart disease (prevalence 0.47 per 1,000). The positive predictive value was 22.8%. There were 22 (59.5%) newly- diagnosed patients and 14 (37.8%) patients (8 newly-diagnosed cases and 6 known cases) required cardiac surgery or interventional catheterization. Conclusion: Cardiac auscultation for heart disease screening by trained nurses and health officers in primary school students can be helpful as a screening tool. Keywords: Cardiac auscultation, Heart disease screening Thai Heart J 2010; 23 : E-Journal : Introduction Congenital heart disease (CHD) is one of the most common heart diseases in children. The incidence of CHD has been reported to be 6-8 in every 1,000 live born babies (1). About half of the children with CHD could be diagnosed within one month of age (2). In Thailand, there is a lack of available information about the incidence of CHD. A study from Siriraj Hospital reported an incidence of CHD of 4.36: 1,000 livebirths (3). Although incidence helps to measure disease development and impact it is practically unknown. Prevalence reflects the occurrence Correspondence: Pentip Supachokchaiwattana, MD Department of Pediatrics, Sawanpracharak Hospital, Nakonsawan, Thailand E mail address: pentip_s@yahoo.com of disease at a point of time in a defined population. Prevalence is much more simply defined and widely acceptable in epidemiologic studies. The reported prevalence of CHD ranged from 9:1,000 to 15-20: 1,000 livebirths (approximately 3:1,000 for clinical severe conditions and 6:1,000 for moderately severe conditions)(4). Plenty of factors could have an impact in prevalence estimation, for example, diagnostic methods, case definition and length of follow up. Prevalence of CHD among children and adults is less known and is still needed. The American Heart Association approximates prevalence of CHD in adults to be about 1: 300 people (4). Prevalence of CHD in school children should be between the prevalence of CHD in livebirths and in adults. The decrease of prevalence can be due directly from the milder form of CHD such as spontaneous closure of small perimembranous ventricular septal defect (VSD) and the

2 Pentip Supachokchaiwattana, MD severe form of CHD such as hypoplastic left heart syndrome causing early life mortality. Most infants with CHD are asymptomatic and have no significant murmur in the initial several days of life during in hospital care. Delayed diagnosis may reflect poor outcome. There are a large number of efforts to screen for CHD, beginning with cardiovascular examination after birth, before discharge, and at well baby clinics. A study from Pramongkutklao Hospital using cardiovascular examination as a screening tool for CHD in newborn infants reported a sensitivity of 38.9% by pediatric residents and 94.4% by pediatric cardiologists (5). The use of pulse oximetry for screening CHD in newborn infants is still under debate and needs standardization (6-10). However, some children with CHD remain undiagnosed during the school period. Studies from Ayudthaya, Tak, Sukhothai and Uttaradit provinces reported the prevalence of unrecognized CHD among healthy primary school students (11-13). There is no previous study of the prevalence of CHD in Nakornsawan province and there is no available study reporting the diagnostic accuracy of cardiac auscultation for heart disease screening in school children. The objectives of the present study were to determine the diagnostic accuracy of cardiac auscultation for heart disease screening by trained nurses and health officers and to study the heart disease screening program in primary school students in Nakornsawan province. Methods This study was approved by the hospital director of Sawanpracharak Hospital. Informed consent was obtained prior to participation. A cross-sectional descriptive study was performed between December 2007 and April Trained nurses and health officers were assigned to do the heart disease screening in a simulated situation in which the prevalence of heart disease was 40%. The patients had pansystolic murmur grade 2-3 from ventricular septal defect and mitral regurgitation. The remainder had no significant murmur. The screeners had to screen 5 children from group 1 (murmurs) or 2 (no murmurs). The correct answer for each patient rewarded 1 point thus the scale score ranged from 0-5. The answers were collected and analyzed to determine the diagnostic accuracy of cardiac auscultation for heart disease screening by trained nurses 133 and health officers in the simulated situation. The sensitivity, specificity, accuracy, positive predictive value, negative predictive value, post test likelihood if the test was negative, and likelihood ratio were calculated. The heart disease screening program was conducted in primary schools in Nakornsawan province. Students with positive screening results were referred to general physicians and then to pediatric cardiologists if suspected of having heart disease as in the normal health care system in Thailand for definite diagnosis and treatment. The Cardiac Childrens Foundation was also asked for cooperation in this program. Prevalence of CHD was calculated. The prevalence rate was the number of students with CHD multiplied by 1,000 and divided by the total number of screened students. Data are shown as mean ± standard deviation. Results There were 244 nurses and health officers who attended the training program and 151participated in the simulated situation in which the prevalence was 40%. The test scores ranged from 2-5; score 2 (1.3%), score 3 (13.2%), score 4 (46.4%), and score 5 (39.1%). The mean score was 4.23 ± In the simulated situation in which the prevalence of heart disease was 40%, cardiac auscultation for heart disease screening by trained nurses and health officers had the following diagnostic accuracy; a sensitivity of 93.7%, a specificity of 78.8%, an accuracy of 84.8%, a positive predictive value of 74.7%, a negative predictive value of 95%, a post test likelihood if the test was negative of 5.1%, and a likelihood ratio of 4.4. A total of 79,319 students from 591 primary schools in Nakornsawan province were enrolled in the heart disease screening program. There were 499 positive results (rate 6.29: 1,000) and 328 students were referred to general physicians (Figure 1). Finally, of the 162 students examined by pediatric cardiologists, 37 students had congenital heart diseases (rate 0.47: 1,000). The positive predictive value was 22.8%. There were 22 (59.5%) newlydiagnosed patients and 14 (37.8%) patients (8 newlydiagnosed cases and 6 known cases) required cardiac surgery or interventional catheterization. The most common CHD was VSD. The CHD subtypes are classified in Table 1.

3 134 Screening for Heart Diseases in Primary School Students in Nakornsawan Province Figure 1. Positive results from heart disease screening program in primary school students in Nakornsawan province. Table 1. Subtype of congentital heart disease detected in the heart disease screening program in primary school students in Nakornsawan province. CHD subtype Number of newlydiagnosed cases Known cases Number of FU referred FU referred Total (%) Ventricular septal defect - VSD (40.5) Atrial septal defect - ASD (2.7) Patent ductus arteriosus - PDA (8.1) Pulmonary stenosis - PS (10.8) Aortic stenosis - AS (8.1) Aortic regurgitation - AR (2.7) Atrioventricular septal defect - AVSD (2.7) Mitral valve prolapse - MVP (5.4) Coronary arteriovenous fistula (5.4) Post operation* (10.8) Cyanotic heart disease (2.7) total (100) FU = follow-up

4 Pentip Supachokchaiwattana, MD Considering the students with a positive screen and no CHD, 32 records of students examined by pediatric cardiologists from the Cardiac Childrens Foundation were reviewed. There were 16 students (50%) with normal cardiac examination, 10 students (31.3 %) with an innocent murmur, 4 students (12.5%) with sinus arrhythmia, and 2 students (6.3 %) with sinus tachycardia and one student (1.3%) with premature ventricular contractions (PVC). The student with PVC also had an innocent murmur. Discussion Cardiac auscultation for heart disease screening by trained nurses and health officers could be helpful as a screening tool. In a simulated situation in which the prevalence of heart disease was 40%, our study found a good sensitivity result (93.7%). Some confounding factors could be from environmental loundness, hastiness, fatigue, uncooperative patients, and an innocent murmur. An innocent or functional murmur could be found as high as 50% (14). Differentiation between an innocent and pathological murmur is difficult since this requires experience, time-consumption and complete cardiovascular examination. In real practice, prevalence of CHD is much lower and confounding factors are much higher. These factors considerably affect the diagnostic accuracy values as the positive predictive value is decreased from 74.7% to 22.8%. The other reason is the use of history in the screening program such as exertional dyspnea, palpitation and chest pain. These symptoms depend on individual perception and usually are not related to structural abnormalities if the physical examination is negative. The reviewed records of students with a positive screen and no CHD represented about half (50%) of them that had heart sounds or rhythms which should be confirmed by experts including innocent murmurs, sinus arrhythmia, sinus tachycardia and PVCs. Innocent murmurs were the most common condition (31.3%) found in the students with a positive screen and no CHD. In spite of the decrease of a positive predictive value, cardiac auscultation for heart disease screening is still promising since the value of 22.8% is still much higher than the prevalence of the disease. The prevalence of CHD in primary school students in Nakornsawan province is 0.47: 1,000. The prevalence here is lower than previous studies from Tak (1.05:1,000), 135 Sukhothai (1.19:1,000) and Uttaradit (0.85:1,000)(11-13) and the figure is probably not the true prevalence of the community. The low prevalence could be from missing data and a different case definition. All positive screening students were not confirmed by our pediatric cardiologists if they had received treatment from other hospitals. The study from Uttaradit included minor disease such as bicuspid aortic valve and mitral regurgitation. Tricuspid and mitral regurgitation were also included in the study from Tak and Sukhothai. The true prevalence of CHD in children also includes the value from population of nonschool and special school children. Further prevalence studies should have ultimate methods to tract for all cases or use of a sample such as the prevalence study of rheumatic heart disease from Cambodia and Mozambique (15). The most common CHD was VSD. The low prevalence of cyanotic heart disease in our study might be from missing data. Patients with cyanotic heart disease had prominent symptoms and signs leading to diagnosis and regular follow up with pediatric cardiologists in certain cardiac centers and were not referred to our pediatric cardiologist. The heart disease screening program conducted in primary schools in Nakornsawan province might not have the full striking impact. Nakornsawan is in the central part of the country and has a relatively good socioeconomic status with convenient communication to all villagers. The study found as high as 22 newly- diagnosed patients that consisted of atrial septal defect (ASD), patent ductus arteriosus (PDA), and coronary AV fistula. These lesions are difficult to detect even in the hand of a pediatrician. Some patients who were lost to follow up care received advice and were back to being followed up again. Nearly half of the known cases (6/15 cases) needed intervention. This might imply non-adherence and strengthens the role of heart disease screening during school age. There were 14 patients (8 newly-diagnosed cases and 6 known cases) referred to have cardiac surgery or interventional catheterization. The cost for the screening program was not expensive and the diseases were mostly treatable. The screening in a rural area with good co-operation with all related organizations would be the most beneficial way to care for our children.

5 136 In conclusion, cardiac auscultation for heart disease screening by trained nurses and health officers in primary school students could be helpful as a screening tool. Acknowledgements The present study was supported in part by a fund form Naresuan University, Thailand. The authors wish to thank the Cardiac Children Foundation of Thailand under the Royal Patronage of H.R.H. Princess Galyani Vadhana Krom Luang Naradhiwas Rajanagarindra and Nakornsawan provincial Health Office, Thailand for supporting this study. Conflict of Interest None References 1. Ferencz C, Rubin JD, Mc Carter RJ. Congenital heart disease: prevalence at live birth. Am J Epidemiol 1985;121: Juttmann RE, Hess J, Looman CW, et al. Screening for congenital heart malformation in child health centers. Int J Epidemiol 1998;27: Loahaprasitiporn D, Jiarakamolchuen T, Chuanthong P, et al. Heart murmur in the first week of life: Siriraj hospital. J Med Assoc Thai 2005;88(suppl 8):S Botto LD, Goldmuntz E, Lin AE. Epidemiology and prevention of congenital heart defects, In Allen HD, Driscoll DJ, Shaddy RE, Feltes TF, eds. Moss and Adams s heart disease in infants, children and adolescents including the fetus and young adult. Philadelphia: Lippincott Williams & Wilkins 2008: Gengsakul A, Tuntrakul C, Kunathai S, et al. Sensitivity of clinical assessment in term neonates by general pediatric residents. J Med Assoc Thai 2005;88(Suppl 3):S Mahale WT, Newburger JW, Matherne GP, et al. Role of pulse oximetry in examining newborns for congenital heart disease: A scientific statement from the American Heart Association and American Academy of Pediatrics. Circulation 2009;120: Koppel RI, Druschel CM, Carter T, et al. Effectiveness of pulse oximetry screening for congenital heart disease in asymptomatic newborns. Pediatrics 2003;111: Sendelbach DM, Jackson GL, Lai SS, et al. Pulse oximetry screening at 4 hours of age to detect critical congenital heart defects. Pediatrics 2008;122:e815-e Granelli AW, Wennergren M, Sanberg K, et al. Impact of pulse oximetry screening on the detection of ductal dependent congenital heart disease: A Swedish prospective screening study in 39,821 newborns. BMJ 2008;337:a3037. Screening for Heart Diseases in Primary School Students in Nakornsawan Province 10. Reich JD, Connolly B, Bradley G, et al. The reliability of single pulse oximetry reading as a screening test for congenital heart disease in otherwise asymptomatic newborn infants. Pediatr Cardiol 2008;29: Sayasathid J, Tantiwongkosri K, Somboonna N. Unrecognized congenital heart disease among Thai Children. J Med Assoc Thai 2009;92: Mongkonsiri D, Taytiwat P, Pankate P. The prevalence of congenital heart disease of elementary school aged students in Sukhothai province. Thai Med Council Bull 2005; 34: Pipatvech K. Abnormal heart sound screening for heart disease in primary school students in Uttaradit Hospital. Uttaradit hospital medical bulletin 2009;2: Smythe JF, Teixeira OH, Vlad P, et al. Initial evaluation of heart murmurs: Are laboratory tests necessary? Pediatrics 1990;86: Marigion E, Ou P, Celermajer DS, et al. Prevalence of rheumatic heart disease detected by echocardiographic screening. New Engl J Med 2007;357:470-6.

6 Pentip Supachokchaiwattana, MD 137 การตรวจค ดกรองโรคห วใจในเด กน กเร ยนช นประถมศ กษา จ งหว ดนครสวรรค เพ ญท พย ศ ภโชคช ยว ฒนา, บ ษกร หล ายเจ ด กล มงานก มารเวชกรรม โรงพยาบาลสวรรค ประชาร กษ จ งหว ดนครสวรรค บทค ดย อ ว ตถ ประสงค : เพ อศ กษาประส ทธ ภาพการค ดกรองโรคห วใจ โดยการตรวจห วใจด วยห ฟ งโดยพยาบาลและเจ าหน าท สาธารณส ข ท ผ านการฝ กอบรมเพ อค นหาเส ยงห วใจท ผ ดปกต และการตรวจค ดกรองโรคห วใจเพ อค นหาผ ป วยโรคห วใจพ การแต กำเน ด และศ กษาความช กของโรคห วใจพ การแต กำเน ดในเด กน กเร ยนช นประถมศ กษา จ งหว ดนครสวรรค ร ปแบบการศ กษา: การว จ ยเช งพรรณนา ณ จ ดเวลาใดเวลาหน ง (Crossectional descriptive study) ว ธ การศ กษา: จ ดการฝ กอบรมพยาบาล เจ าหน าท สาธารณส ขเร องการตรวจค ดกรองโรคห วใจโดยการใช ห ฟ งเพ อค นหาเส ยง ห วใจท ผ ดปกต ประเม นผลการฝ กอบรมโดยการจำลองสถานการณ ให ค ดกรองแยกเด กโรคห วใจพ การและเด กปกต ตรวจค ดกรองเด กน กเร ยนช นประถมศ กษาระหว าง มกราคม เมษายน 2551 และส งเด กท ม ผลการค ดกรองท ผ ดปกต เข าร บการตรวจย นย นการว น จฉ ยโดยก มารแพทย โรคห วใจท โรงพยาบาลสวรรค ประชาร กษ จ งหว ดนครสวรรค ว เคราะห ผลโดยใช สถ ต เช งพรรณนา ได แก การแจกแจงความถ ร อยละ ค าเฉล ยและส วนเบ ยงเบนมาตรฐาน สถ ต เช งอน มาน ได แก การหาอ ตราความช กของโรคห วใจพ การแต กำเน ด ผลการศ กษา: ม พยาบาลและเจ าหน าท สาธารณส ขในจ งหว ดนครสวรรค เข าร บการฝ กอบรม 244 ราย และเข าร บการประเม น ผลการฝ กอบรม 151 ราย โดยการจำลองสถานการณ ให ค ดกรองแยกเด กโรคห วใจและเด กปกต โดยม ความช กของโรคห วใจ เป น 40% พบว าการค ดกรองโดยใช ห ฟ งเพ อค นหาโรคห วใจพ การโดยการฟ งเส ยงห วใจท ผ ดปกต ม ค า sensitivity 93.7%, specificity 78.8%, accuracy 84.8%, positive predictive value 74.7%, negative predictive value 95%, post test likelihood if test negative 5.1%, likelihood ratio 4.4 จำนวนน กเร ยนท ได ร บการตรวจค ดกรอง 79,319 ราย จาก 591 โรงเร ยน ม น กเร ยนท ม ผลการค ดกรองผ ดปกต 499 ราย ค ดเป น 6.29 ต อประชากร 1,000 ราย แนะนำให ส งต อเพ อตรวจย นย น 328 ราย ม น กเร ยนมาตรวจท โรงพยาบาลสวรรค ประชาร กษ 162 ราย พบม โรค ห วใจพ การแต กำเน ด 37 ราย ค ดเป นความช กโรคห วใจพ การแต กำเน ดในเด กน กเร ยนช น ประถม ศ กษา 0.47 ต อประชากร 1,000 ราย การค ดกรองโรคห วใจพ การม ค า positive predictive value 22.8% โรคห วใจท พบมากท ส ดค อ VSD 14 ราย ม ผ ป วยท ได ร บการว น จฉ ยใหม 22 ราย ม ผ ป วย 14 รายท ส งร กษาต อเพ อแก ไขโดยการผ าต ด หร อสวนห วใจ สร ปผลการศ กษา: การค ดกรองโรคห วใจโดยการใช ห ฟ งเพ อค นหาเส ยงห วใจท ผ ดปกต โดยพยาบาลและเจ าหน าท สาธารณส ข ท ได ร บการอบรม เป นว ธ การค ดกรองท ม ประส ทธ ภาพ สะดวก รวดเร ว ราคาไม แพง สามารถใช ค ดกรองโรคห วใจพ การได เก ดประโยชน ก บเด กท ไม เคยได ร บการว น จฉ ยมาก อนเน องจากเป นเด กกล มท ด แข งแรง ไม ม อาการผ ดปกต ขณะท ผ ป วยราย เก าท ขาดการร กษาต ดตามก ได แนะนำผ ปกครองให ไปตรวจร กษาต อเน อง เพ มโอกาสการร กษาท รวดเร วและเหมาะสมท น เวลาก บผ ป วยท งเก าและใหม การค ดกรองในจ งหว ดท ห างไกลน าจะเก ดประโยชน ส งส ด