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Keywords:

  • schistosomiasis;
  • pulmonary hypertension;
  • echocardiography
  • schistosomiase;
  • hypertension pulmonaire;
  • échocardiographie
  • Esquistosomiasis;
  • hipertensión pulmonar;
  • ecocardiografía

Abstract

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References

Objectives  Millions of people in the developing world may suffer from pulmonary hypertension (PHTN) because of preexisting infectious conditions. Schistosomiasis can cause pulmonary lesions that eventually lead to PHTN. The aim of this study was to assess the prevalence of PHTN together with assessment of right ventricular (RV) function in asymptomatic rural residents previously infected with schistosomiasis.

Methods  Three hundred and seventy asymptomatic people from an endemic area in the Nile Delta were screened for antibodies against schistosomiasis. All were scheduled for transthoracic echocardiographic study to assess pulmonary artery systolic (PASP) and diastolic (PADP) pressures as well as RV function. PASP >40 mmHg was considered elevated.

Results  Seropositive (SP) and seronegative (SN) groups had comparable age and body mass index. PASP >40 mmHg was met in 18 subjects (Range 42–72 mmHg) (8.6%) of SP group and in no subject in SN group (P = 0.000). Compared with SN group, the SP group had higher mean values of PASP (30 ± 10 vs. 24 ± 7 mmHg, P < 0.000) and PADP (12 ± 4 vs. 9 ± 3 mmHg, P < 0.000). The SP group had lower values of RV ejection fraction.

Conclusion  Prevalence of PHTN as detected by echocardiography in asymptomatic rural residents with schistosomiasis in Nile Delta is low with mild affection of RV function.

Objectifs:  Des millions de personnes dans les pays en développement pourraient souffrir d’hypertension pulmonaire (HTP) à cause de conditions infectieuses préexistantes. La schistosomiase peut provoquer des lésions pulmonaires qui finissent par conduire à l’HTP. L’objectif de cette étude est d’évaluer la prévalence de l’HTP ainsi qu’une évaluation de la fonction ventriculaire droite chez des résidents ruraux asymptomatiques précédemment infectés par la schistosomiase.

Méthodes:  370 personnes asymptomatiques dans une zone endémique dans le delta du Nil ont été testées pour les anticorps de la schistosomiase. Toutes ont été soumises à l’échocardiographie trans-thoracique pour évaluer la pression artérielle pulmonaire systolique (PAPS) et diastolique (PAPD) ainsi que la fonction ventriculaire droite. PAPS> 40 mmHg a été considérée comme élevée.

Résultats:  Les groupes séropositifs (SP) et séronégatifs (SN) avaient un âge et un indice de masse corporelle comparables. PAPS > 40 mmHg (intervalle de 42 à 72 mmHg) a été rencontrée chez 18 (8,6%) sujets du groupe SP et chez aucun sujet du groupe SN (p = 0,000). Comparé au groupe SN, le groupe SP avait des valeurs moyennes plus élevées de la PAPS (30 ± 10 vs 24 ± 7 mmHg, p < 0,000) et de la PAPD (12 ± 4 vs 9 ± 3 mmHg, p < 0,000). Le groupe SP avait des valeurs plus basses de la fraction d’éjection ventriculaire droite.

Conclusion:  La prévalence de l’HTP telle que détectée par échocardiographie chez les résidents ruraux asymptomatiques avec schistosomiase dans le delta du Nil est faible, avec une affection bénigne de la fonction ventriculaire droite.

Objetivos:  Millones de personas en países en desarrollo podrían sufrir de hipertensión pulmonar (HTPR) por condiciones infecciosas pre-existentes. La esquistosomiasis puede producir lesiones pulmonares que eventualmente conllevan a un HTPR. El objetivo de este estudio era evaluar la prevalencia de la HTPR junto con la evaluación de la función ventricular derecha en residentes rurales asintomáticos previamente infectados con esquistosomiasis.

Métodos:  Se midió el nivel de anticuerpos contra esquistosoma en 370 personas asintomáticas de áreas endémicas del Delta del Nilo. A todos se les programó una ecocardiografía torácica para evaluar las presiones sistólica (PSAP) y diastólica (PDAP) en arteria pulmonar, así como la función ventricular derecha. Se consideró como elevada una PSAP > 40 mmHg.

Resultados:  Los grupos seropositivos (SP) y seronegativos (SN) tenían una edad e índice de masa corporal comparables. 18 sujetos (8.6%) del grupo SP y ningún sujeto del grupo SN (p = 0.000) tenían una PSAP >40 mmHg (rango 42-72 mmHg). Comparados con el grupo SN, el grupo SP tenía valores medios más altos de PSAP (30 ± 10 vs. 24 ± 7 mmHg, p < 0.000) y PDAP (12 ± 4 vs. 9 ± 3 mmHg, p < 0.000). El grupo SP tenía valores menores en la fracción de eyección del ventrículo derecho.

Conclusión:  La prevalencia de la HTPR detectada mediante ecocardiografía en habitantes de zonas rurales del Delta del Nilo y con esquistosomiasis asintomática es baja, con poca afectación de la función ventricular derecha.


Introduction

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References

Schistosomiasis is the third leading endemic parasitic disease in the world, following malaria and amoebiasis. Currently, more than 200 million people in 74 countries have this disease, of whom 120 million have symptoms (Chitsulo et al. 2000). In Egypt, the national schistosomiasis control programme has resulted in accelerating the decline of schistosomiasis, although extended perennial irrigation and the rising population created conditions favourable for schistosomiasis transmission. Schistosoma hematobium rates declined from around 60–70% in 1925 to 5% in 1996, and Schistosoma mansoni rates fell from 32% in 1932 to 12% in 1996 (Cline et al. 1989; El Khoby et al. 1998).

The first description of cardiopulmonary manifestations of schistosomiasis appeared in the early 1900s (Shaw & Ghareeb 1938) when it was reported that the lung is a mandatory step in the schistosomal life cycle. Most cardiopulmonary manifestations of schistosomiasis are thought to be related to the hepatosplenic form of the disease (Lapa et al. 2009). Portal hypertension opens more collateral circulation, thus increasing blood flow to the lungs and enhances shear stress in pulmonary vessels (Ghazwan & Morrell 2009). The association of pulmonary hypertension with schistosomiasis favours the concept that specific causes of pulmonary hypertension may be of particular importance in developing countries (Humbert et al. 2007).

While there are no substantive reports of the true incidence of schistosomiasis-related pulmonary hypertension in Egypt, most observational studies from endemic areas worldwide have suggested that pulmonary hypertension occurs in 5% to 21% of patients infected with schistosomiasis (Andrade & Bina 1985; El Hawey et al. 1992; Barbosa et al. 1996; Lambertucci et al. 2000).

This study was designed to assess the prevalence and magnitude of pulmonary hypertension and its effect on right ventricular (RV) function among rural Egyptians previously infected with schistosomiasis in the Nile Delta.

Materials and methods

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References

Study population

The protocol of this study was approved by the local institutional review board. Five hundred and fifty-one asymptomatic subjects from an endemic area in the Nile Delta who were verbally consented were screened for antibodies against schistosomiasis (mansoni and/or haematobium). The sample examined was selected from Alsharqiya governorate after advertisement in a local newspaper calling for voluntary participation in the project. Alsharqiya governorate is located in the north-east of Egypt, near the centre of the Delta with demographic features very well representative of the Delta region. It covers 4911 km2 and comprises a large number of villages and ezbas (satellite groups of dwellings). The total population of Alsharqiya is 5.7 million, 7.1% of the total Egyptian population.

Two hundred and seventeen people (39.4%) tested seropositive (SP). As our budget could not support including all participants, we randomly selected 50% of seronegative (SN) subjects to serve as a control group. All SP patients and 167 of the SN participants were scheduled for detailed history taking, full clinical examination, electrocardiogram (ECG) as well as detailed transthoracic echocardiographic study for assessment of RV function and calculation of pulmonary artery pressures. Twelve patients (seven of the SP group and five of the SN group) were excluded because of cardiac disorders that may affect RV function or pulmonary artery pressures (four with ischaemic heart disease, four with rheumatic valve affection, one with atrial septal defect and three with mitral valve prolapse). Two subjects of the SN group were also excluded because of poor imaging quality.

Echocardiographic study

A standard echocardiographic study was carried out by using Esaote-My Lab-50 equipped with a 2.5-MHz transducer. A single echocardiographer who was blinded to serology results carried out all studies.

M-mode measurements of the left ventricle were obtained during end systole and end diastole with calculation of left ventricular ejection fraction (LVEF) as per American Society of Echocardiography recommendations (Lang et al. 2005). The three RV dimensions (at the level of tricuspid annulus, mid-cavity and long axis) (Lang et al. 2005) were measured. RV volumes were assessed by area–length method (Apfel et al. 1996; Denslow & Wiles 1998) to calculate RV ejection fraction (RVEF). An M-mode cursor was then placed at the level of lateral tricuspid annulus to obtain the tricuspid annular plane systolic excursion (TAPSE) (Samad et al. 2002). TAPSE was measured as the total displacement of the tricuspid annulus (mm) from end diastole to end systole. A pulsed wave Doppler was used to record the tricuspid and pulmonary flows. RV myocardial performance index (RV MPI) was calculated according to the following formula (Tei 1995):

  • image

where the sum of [IVCT + IVRT] was simply derived from subtracting the pulmonary ejection time from the time interval between cessation and onset of two consecutive tricuspid flows.

The systolic tricuspid regurgitation (TR) pressure gradient between the right ventricle and the right atrium and the pulmonary regurgitation end diastolic velocity were calculated by the simplified Bernoulli equation (Yock & Popp 1984). Right atrial (RA) pressure was estimated according to the degree of inferior vena cava inspiratory collapse. The pulmonary artery systolic and diastolic pressures were then calculated. Pulmonary artery systolic pressure (PASP) was considered elevated if it exceeded 40 mmHg. Colour-coded Doppler was used to estimate the TR jet area (even trivial amount of TR was recorded). Vena contracta (VC) width was determined by positioning the transducer to optimize visualization of the flow convergence region and the regurgitant flow proximal and distal to the tricuspid valve (Tribouilloy et al. 2000). It was measured as the narrowest neck of the regurgitant flow just distal to the flow convergence region in mid-systole. RA area at end systole was planimetered, and then, TR area/RA area was calculated.

Serodiagnosis of schistosomiasis by indirect haemagglutination (IHA)

The IHA test assay with adult S. mansoni worm antigen produced by Fumoze Laboratories (Levallois-Perret, France) was used according to the manufacturer’s instructions. It allowed the detection of antibodies present in sera of patients suffering from schistosomiasis with S. mansoni or S. hematobium. We used freshly withdrawn sera for the whole studied population. Titres equal to or above 1:160 were considered significant reactions.

Statistical analysis

Data from categorical variables were summarized as frequencies, which were compared between SP and SN groups using chi-squared or Fisher’s exact test. Data from continuous variables were summarized as mean ± SD. Comparison between SP and SN groups was made using the Mann–Whitney U-test. Student t-test was used when data were confirmed to be normally distributed. Two-tailed P-values <0.05 were considered statistically significant. All statistical analyses were performed using SPSS version 16.0 software for windows (SPSS Inc. Chicago, IL, USA).

Results

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References

Demographic and clinical characteristics

Three hundred and seventy subjects completed the study protocol; 210 were SP, and 160 were SN. Demographic and clinical characteristics of both groups are shown in Table 1. Both groups had comparable age, body mass index (BMI) and vital signs. However, the SP group had higher proportion of male gender. All subjects studied were in normal sinus rhythm. Previous diagnosis with schistosomiasis was met in only 12 patients of SP group (5.8%). Six patients (2.9%) of the same group gave a past history of haematuria. Antischistosomal medications were received by 93 (44.3%) of the SP group compared to 41 (25.6%) of SN group, P < 0.000. Both groups received their medications at a comparable age (22 ± 11 vs. 19 ± 8 years, P = 0.124). History of shortness of breath and fatigue were shown more frequently in the SP group (P = 0.003 and P = 0.001, respectively). No subject gave history of effort syncope, angina pectoris or hemoptysis. Only two patients (1%) belonging to the SP group had clinical hepatomegaly with no clinically detectable spleen or ascites. Both patients had clinical signs of RV hypertrophy and systolic murmur of TR. More than 99% of the SN group showed normal ECG compared with 88% of SP group. ECG abnormalities included right bundle branch block morphology, RA and/or RV hypertrophy and non-specific ST-T changes in right pre-cordial leads.

Table 1. Demographic characteristics of seropositive (SP) and seronegative (SN) groups
Demographic and clinical dataSP (n = 210)SN (n = 160) P-value
  1. SOB, shortness of breath; RVH, right ventricular hypertrophy; BMI, body mass index; HR, heart rate; SBP, systolic blood pressure; DBP, diastolic blood pressure; ECG, electrocardiogram.

Age (years)35 ± 1233 ± 140.124
Male (%)152 (72.4)99 (61.9)0.034
SOB (%)22 (10.5)4 (2.5)0.003
Fatigue (%)23 (11)3 (1.9)0.001
Past history of haematuria (%)6 (2.9)0 (0)0.039
Hepatomegaly (%)2 (1)0 (0)0.508
RVH (%)2 (1)0 (0)0.508
BMI (kg/m2)27.5 ± 5.427.7 ± 5.50.634
HR (beat/min)75 ± 1275 ± 100.883
SBP (mmHg)123 ± 15121 ± 140.297
DBP (mmHg)77 ± 1079 ± 80.103
Normal ECG (%)185 (88)159 (99.4)<0.000

Echocardiographic analysis

Echocardiographic results of both groups are summarized in Table 2. Although the mean values for all echocardiographic parameters to assess left and RV function were found to be within normal limits, there was widespread of values between both groups. Subjects in the SP group had increased mean values of LVEF, RV diameters, RA area, VC width and pulmonary artery pressures. On contrary, they had decreased mean values of RVEF and TAPSE.

Table 2. Echocardiographic analysis of seropositive (SP) and seronegative (SN) groups
Echocardiographic measurementsSP (n = 210)SN (n = 160) P-value
  1. LVEF, left ventricular ejection fraction; RV, right ventricle; RVEF, right ventricular ejection fraction; TAPSE, tricuspid annular plane systolic excursion; RV MPI, right ventricular myocardial performance index; RA, right atrium; TR, tricuspid regurgitation; VC, vena contracta; PASP, pulmonary artery systolic pressure; PADP, pulmonary artery diastolic pressure.

LVEF (%)73.3 ± 6.571.9 ± 6.50.036
RV dimension at annular level (mm)31.3 ± 5.230.4 ± 3.90.057
RV dimension at mid-cavity (mm)29.3 ± 727.2 ± 4.70.001
RV long-axis dimension (mm)70.7 ± 9.468.1 ± 7.40.004
RVEF (%)58.1 ± 8.460.9 ± 7.70.001
TAPSE (mm)26.2 ± 4.227.3 ± 3.60.013
RV MPI0.32 ± 0.150.30 ± 0.130.573
RA area (cm2)14.2 ± 4.711.5 ± 3.2<0.000
TR area/RA area0.11 ± 0.060.11 ± 0.050.108
VC width (mm)0.33 ± 0.120.29 ± 0.09<0.000
PASP mmHg30.2 ± 9.624.1 ± 6.9<0.000
PADP mmHg11.7 ± 3.88.7 ± 3<0.000

Pulmonary hypertension

Of the 370 subjects studied, 18 had PASP >40 mmHg (range, 42–72 mmHg). All belonged to the SP group representing 8.6% of this group.

Within the SP group, patients with echocardiographic evidence of pulmonary hypertension and patients with normal pulmonary artery pressure had comparable age, gender distribution, BMI, vital signs and frequency of receiving antischistosomal medications (Table 3). ECG was within normal limits in 12 patients (66.7%) with elevated pulmonary pressure compared to 173 (90.1%) in patients with normal pulmonary artery pressure (P = 0.011).

Table 3. Demographic characteristics of patients with echocardiographic evidence of pulmonary hypertension and patients with normal pulmonary artery pressure
Demographic dataEchocardiographic evidence of pulmonary hypertension (n = 18)Normal pulmonary artery pressure (n = 192) P-value
  1. BMI, body mass index; HR, heart rate; SBP, systolic blood pressure; DBP, diastolic blood pressure; AS, anti-schistosomal; ECG, electrocardiogram; RBBB, right bundle branch block; RA, right atrium; RVH, right ventricular hypertrophy.

Age (years)37 ± 1135 ± 120.388
Male (%)14 (77.8)138 (71.9)0.784
BMI kg/m227.5 ± 5.127.5 ± 5.40.964
HR (beat/min)76 ± 1275 ± 120.552
SBP (mmHg)123 ± 13122 ± 160.844
DBP (mmHg)74 ± 877 ± 110.144
Received AS medication (%)11 (61.1)82 (42.7)0.145
Normal ECG (%)12 (66.7)173 (90.1)0.011
RBBB morphology (%)2 (11.1)5 (2.6)0.113
RA enlargement (%)1 (5.6)00.086
RVH (%)2 (11.1)00.007
Non-specific ST-T changes (%)2 (11.1)00.007

By echocardiography, it has been detected that patients with elevated pulmonary pressure had higher mean values of LVEF, RV diameters, RV MPI, tricuspid regurgitation area/right atrial area and VC width. However, they had lower mean values of RVEF as shown in Table 4.

Table 4. Echocardiographic data of patients with elevated pulmonary artery pressure and patients with normal pulmonary artery pressure
Echocardiographic measurementsElevated pulmonary artery pressure (n = 18)Normal pulmonary artery pressure (n = 192) P-value
  1. LVEF, left ventricular ejection fraction; RV, right ventricle; RVEF, right ventricular ejection fraction; TAPSE, tricuspid annular plane systolic excursion; RV MPI, right ventricular myocardial performance index; RA, right atrium; TR, tricuspid regurgitation; VC, vena contracta; PASP, pulmonary artery systolic pressure; PADP, pulmonary artery diastolic pressure.

LVEF (%)76.8 ± 7.673 ± 6.30.018
RV dimension at annular level (mm)36.1 ± 6.930.9 ± 4.8<0.000
RV dimension at mid cavity (mm)36.4 ± 12.828.7 ± 5.8<0.000
RV long-axis dimension (mm)75.6 ± 7.870.2 ± 9.40.019
RVEF (%)50.4 ± 8.358.9 ± 8<0.000
TAPSE (mm)26.3 ± 4.526.2 ± 4.20.959
RV MPI0.39 ± 0.180.31 ± 0.140.041
RA area (cm2)18.1 ± 9.713.9 ± 3.80.113
TR area/RA area0.14 ± 0.070.11 ± 0.060.012
VC width (mm)0.42 ± 0.20.32 ± 0.10.025
PASP mmHg50.9 ± 13.228.2 ± 6.3<0.000
PADP mmHg18.4 ± 4.511.1 ± 3<0.000

Discussion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References

This study showed an 8.6% prevalence of increased pulmonary artery pressure by echocardiography in asymptomatic subjects previously infected with schistosomiasis who live in endemic area in the Nile Delta. Most patients had modest elevation of pulmonary pressure with preservation of RV function as assessed by transthoracic echocardiography. Although apparently healthy, the prevalence of SP subjects in our study population was 39.4%.

The most intensive epidemiological research project ever carried out by the Egyptian government showed that there was considerable variation in the prevalence of the two types of schistosomiasis: S. mansoni overtook S. hematobium as the predominant Schistosoma species in Egypt with an average prevalence rate of 36.4% in Lower Egypt and Nile Delta (El Khoby et al. 2000).

The laboratory test used for serodiagnosis of the studied population was a commercial IHA test using erythrocytes coated with schistosoma adult worm antigen. Previous studies showed that IHA test ensures good sensitivity and specificity for the reaction. One study showed that the sensitivities of the test with cut off titre of 1:160 were 88% and 80% for the detection of S. mansoni and S. hematobium, respectively, and a specificity of 98.9% for both (van Gool et al. 2002). The IHA test is easy and fast to perform, and the results are usually obtained within 2 h. The detection of antibodies per se is useful in patients with no eggs or a low egg burden (Tsang & Wilkins 1997).

Nearly 40% of our population sample was proved to be positive for the test with male gender preponderance. Men in endemic areas were more exposed to activities like fishing, farming in irrigated fields or swimming that all bring them into contact with canal water contaminated by faeces or urine of infected people and animals. Symptoms of shortness of breath, fatigue, past history of haematuria and clinical signs of hepatomegaly and RV enlargement were met in no more than 5% of SP group and in none of the SN group. Since 1993, 99% of the Egyptian population had access to health services and 90% to safe water (United Nations Development Programme 1995). Public health officials tried various methods to emphasize widespread use of praziquantel either in the entire community or in particular high-risk populations such as school children (El Khoby et al. 2000).

As there are no systematic epidemiological studies on the prevalence of pulmonary hypertension in schistosomiasis, we conducted this study to clarify the prevalence of this problem in rural Egyptians who are apparently healthy but had previous infection with schistosomiasis and live in an endemic area. A recent screening study has demonstrated a 4.6% prevalence of pulmonary hypertension in patients with hepatosplenic schistosomiasis (Lapa et al. 2009). In Sudan, a pilot study has been conducted on complicated patients infected with schistosoma (n = 57) referred for treatment in Khartoum to assess the prevalence of pulmonary hypertension among Sudanese patients with schistosomiasis. Preliminary analysis of the data showed prevalence of mild pulmonary hypertension in more than 50% of the echocardiographically examined patients (Ghazwan & Morrell 2009). The prevalence of echocardiographic elevation of pulmonary artery pressure in SP group of our sample population was 8.6% (18/210); most of them were mild. This modest elevation of pulmonary artery pressure in some patients with schistosomiasis provides no guarantee against progressive deterioration whether spontaneously or as a consequence of repeated infection. This necessitates periodic follow-up of these patients.

On the other hand, this study strengthens the role of echocardiography as a screening tool in field survey studies. Although PASP >40 mmHg is usually higher than the real prevalence of pulmonary hypertension as measured by invasive haemodynamics, echocardiography still have the major role for the indication of right heart catheterization, the gold standard for diagnosis of pulmonary hypertension (Lapa et al. 2009). A previous study (Barst et al. 2004) showed that TR peak velocity has a high linear positive correlation (0.57–0.93) with PASP measured at right heart catheterization and that the reported sensitivity of Doppler-estimated PASP for detecting pulmonary hypertension ranges from 0.79 to 1.00 and specificity from 0.60 to 0.98.

It is important to note that one of the known mechanisms of pulmonary hypertension in patients infected with schistosoma is the coexistence of portopulmonary hypertension and occasional increase in cardiac output with consequent pulmonary vascular hyperflow (Hovnanian et al. 2010). This may lead to false-positive increase in PASP when measured by echocardiography (Bossone et al. 2007). However, as none of our participants had symptoms or signs of portal hypertension or liver cirrhosis, false positivity of echocardiographic elevation of systolic pulmonary pressure became less likely.

RV function is an important predictor in the course of schistosomal infection. Two echocardiographic parameters have been used to improve measurements of RV function: the TAPSE and the global MPI.

Tricuspid annular plane systolic excursion closely correlates with RVEF (Kaul et al. 1984), and its clinical and prognostic significance had been tested in adult patients with pulmonary hypertension. It was found that TAPSE <1.8 cm2 was associated with greater RV systolic dysfunction (Forfia et al. 2006). Our study showed a significant decrease in TAPSE of SP group compared with that of SN group. However, patients with elevated pulmonary artery pressure did not differ significantly compared to those with normal pulmonary artery pressure. This may reflect preservation of RV longitudinal contraction in patients with modest pulmonary hypertension. On the other hand, MPI that encompasses important energy-dependent periods of systolic contraction, ejection and diastolic relaxation has been validated in patients with primary pulmonary hypertension (Yeo et al. 1998), and it has been shown to have prognostic relevance. As global myocardial dysfunction progresses, the value for the MPI increases, owing to the changes in all three time interval components used for its calculation. Our study showed significant increase of MPI in patients with elevated pulmonary artery pressure compared to patients with normal pulmonary artery pressure (0.39 ± 0.18 vs. 0.30 ± 0.14, P = 0.041).

The current study had some limitations. First, the study sample was relatively small, and was randomly selected from one governorate in the Nile Delta. We therefore acknowledge that this sample may not be representative of the actual prevalence of schistosomiasis-related pulmonary hypertension in the whole endemic areas in Egypt. Second, invasive hemodynamic assessment to confirm pulmonary artery pressures was not performed.

Conclusion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References

Prevalence of echocardiographic elevation of pulmonary artery pressure in asymptomatic rural Egyptians with schistosomiasis in the Nile Delta is low. Echocardiography has a major role as a screening tool for the detection of pulmonary hypertension. Mild affection of RV function highlights the need for periodic follow-up of these patients.

Acknowledgements

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References

We thank patients for participating in this study. This study was supported by a research grant from Magdi Yacoub Heart Foundation.

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  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Acknowledgements
  9. References
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