Rheumatic valvular heart disease (RVHD) is a complication of rheumatic fever that frequently affects several valves, predominantly the mitral (60%), followed by the aortic valve (30%) and the tricuspid valve [1]. It remains a significant cardiovascular disease in the world. Although estimates of global prevalence and incidence are inaccurate [2], the overall burden is estimated to be at 15.6 million in prevalence with 282,000 new cases and over 233,000 deaths per year [3]. According to a WHO 2019 report, the South Pacific region is one of the regions with the highest number of RVHD [4]. Despite, significant improvement in the care and outcomes of patients with rheumatic fever through early diagnosis and the upscaling of benzylpenicillin prophylaxis globally, the morbidity and mortality remain high [5-7]. These are due to the long asymptomatic stage of the disease process and the lack of early detection and management [7]. Furthermore, the limited cardiac surgical services in the low middle income countries (LMIC) are far from meeting the needs of the high disease burden they are facing [8,9]. International medical mission trips from countries with expertise have provided rare opportunities for patients suffering from RVHD to receive lifesaving cardiac surgeries [10]. The short-term clinical outcomes from such programs are well documented [11 -13]. And in the hands of experienced surgeons with regular high volumes, the outcomes are satisfactory [14].

Papua New Guinea (PNG), a LMIC in the Oceania region of the South Pacific Region has received consistent cardiac surgeries support from its neighbouring country, Australia for over 30 years, who predominantly has been operating on the paediatric population [11,12]. Most adult patients unfortunately, did not have a chance for surgery due to the complexities of the cases and the lack of surgical expertise. Our centre has previously shown that with strict screening by an expert multidisciplinary Heart team, the outcomes in the paediatric valvular heart disease cases were satisfactory [11,12]. In this case series, we discuss the outcomes of six adult patients with rheumatic heart disease who underwent open heart surgeries by a visiting expert Heart team from Singapore. This group of patients had complex rheumatic valvular pathology with  multivalvular involvement, cardiac chamber size remodelling and high pulmonary arterial pressures. Transthoracic echocardiography was used as the gold standard for diagnosis.

A total of fifteen adult patients aged between 18 – 54 years with valvular heart disease were referred by physicians from all over the country to our national central hospital for consideration for surgery. Their baseline demographic, clinical and echocardiographic data were collected and screened. Seven patients were identified as candidates for surgery by the Heart team comprised of cardiac surgeons, cardiologists, and cardic anaesthetists (Table 1). Written consents for data collection and research were obtained from the patients after approval by the hospital research ethical committee. Clinical and echocardiographic data were collected before and immediate post operation when inpatient, at one month, three months and one year during follow up (Table 1). Microsoft excel was used for statistical storage and analysis. Categorical data were expressed as percentages whilst numerical data were expressed as means.

Six out of seven eligible patients aged between 24 – 47 years underwent open heart surgeries. The mean age was 36±2 years, and 57% were female. All the female patients had isolated severe mitral stenosis associated with dilated left atrium (LA). They had mitral valve repairs with left atrial annuloplasty. The two male patients had mixed valvular heart diseases. One had mitral valve repair, and another had mitral valve replacement. Both had LA annuloplasty (Table 1). There were no postoperative complications, and the average length of hospital stay was 5 days. All patients had equal functional classes between NYHA Class II and III preoperatively. 86% achieved NYHA Class I postoperatively in one year (Table 1). Their mean pulmonary artery systolic arterial pressure (PASP) was 57.7 mmHg preoperative and was 42.4mmHg postoperative, a drop of 15.3mmHg (Figure 1). Additionally, there were improvement in the left ventricular end diastolic dimension over the 12 months (Figure 2).

Table 1: Characteristics of patients who underwent cardiac surgery.

©Withdrew before surgery

AR = Aortic regurgitation, AF = Atrial LA = Left atrium, PHTN = Pulmonary hypertension, RHD = Rheumatic heart disease, PSAP = Pulmonary systolic arterial pressure, LVEDD = Left Ventricular end diastolic dimension, LVESD = Left ventricular end systolic dimension, EF = Ejection fraction, LVF = Left ventricular failure, NYHA Class = New York Heart Association Class.

Figure 1: Progressive LVEDD (mmHg) over 12 months.

Figure 2: Progressive PSAP (mmHg) over 12 months.

The early diagnosis and treatment of rheumatic fever (RF) remains a significant challenge for physicians in the high prevalent countries [15]. Studies have shown that, RF complicating RVHD could remain asymptomatic for decades [16-18] before showing signs and symptoms of heart failure. This leads to late diagnosis with poor suitability of valves anatomy and irreversible haemodynamic changes that invalidates amenable surgery. Careful case selection based on optimal screening and surgical decision-making have shown to produce satisfactory outcomes [ 11-13]. Russel et. al., have shown that clinical outcomes in RVHD undergoing valve surgery is similar to non RVHD, except in those who are elderly, diabetic and have concomitant atrial fibrillation (AF) [19]. All patients in our case series, had uncomplicated surgeries, with short inpatient stay and significant improvement in the haemodynamic and functional status over 12 months. These are consistent with the short-term outcomes of RVHD surgeries in other parts of the world [13]. Our centre has experience with annual cardiac surgeries predominantly with the paediatrics patients conducted by an international visiting team over the last 3 decades and the patient’s outcomes and the transfer of skills to the local team are satisfactory and well documented [11,12]. All patients in our case series were young with a mean age of 35 years of age. There were no major significant comorbidities except two male patients with atrial fibrillation (AF). 66% of the patients (all females) had isolated severe mitral stenosis complicated by significant left atrial dilatation and moderate to high pulmonary arterial systolic pressure (PASP). 24% (two males) had both aortic and mitral valves involvement with significant morphological deformities associated with haemodynamic changes (Table 1). Munashsur et.al., have shown that, severe pulmonary artery pressure post-surgery among RHVD surgery is associated with significant adverse cardiovascular events [20]. Our series, however, shows consistent decline in PASP with a mean drop of 15.3mmHg. Although, quantitative assessment of the preoperative reversibility of the pulmonary arterial pressure through right heart study wasn’t institutionally feasible, we believe, the meticulous scrutiny of the patient profile by a designated “Heart team” with their vast experience in complex valve reconstructive surgeries has produced satisfactory outcome in our series. All patients had short hospital stay with no post-operative complications. They have shown significant haemodynamic (PASP) improvement with corresponding clinical and cardiac chambers improvement over the follow up period. Although, the immediate and first year outcome of this case series is satisfactory, it is not possible to assess the long-term outcomes as due to the limitation of follow up in the local context. This case series have illustrates that medical missionaries providing lifesaving surgeries for the LMIC with high burden of RVHD continue to provide a lifeline for those who could have been part of the dismal mortality of the RF. Several factors we believe have contributed to the success of the outcome in this case series. Firstly, optimal screening of the RVHD patients with stringent selection by an expert multidisciplinary Heart team from a high-volume centre of valve repair and replacement had significantly contributed to the satisfactory outcome [14]. Secondly, the series were among a young medically fit group of patients with no significant comorbidities, good functional status with moderate to severe RVHD. The outcomes in such a population have been shown to be satisfactory [19], albeit in our series in the intermediate period after surgery. This suggests that, in LMIC where expertise is lacking, expert missionary cardiothoracic teams can still achieve better selective outcomes for young patients with complex RVHD. This was a retrospective case series, and we are aware of lack of completeness of data inclusion. Patient’s selection has been done by the multidisciplinary Heart team for surgery and selection bias is unavoidable. Additionally, the patient’s data were not collected in a standardised way and therefore, the series can have data bias as we collected the pre- and post-operative outcomes during our routine care of the patients. A similar large observational study by Tamirat et.al in Ethiopia has shown nearly a quarter of their patients had a major adverse valve related event and 11 deaths [ 21]. We, however, had no long term follow up to determine the long-term outcomes of our cases and the subgroups of patients with valve repair vs replacement. The highlight of RF as a leading cause of morbidity in cardiovascular disease by the WHO is improving early detection and medical treatment. Comparing early medical treatment vs watchful waiting for RF is an area that may contribute to the further understanding the natural history of RF progression. Further, establishing a national RF registry helps in public health interventions and research as RVHD has country to country variability and this will contribute to optimal interventions to improve care. Although, RVHD have poor outcomes in the LMIC [22] with high prevalences, early optimal screening and selection by an expert multidisciplinary cardiothoracic team experienced in high case volume would achieve satisfactory outcome in a young population with no significant comorbidities.

Young patients with no significant comorbidities in the LMIC with complex rheumatic valvular heart diseases can undergo successful reconstructive surgeries under careful selection by experienced multidisciplinary cardiothoracic multidisciplinary team.

Abbreviations:

RVHD: rheumatic valvular heart disease; LMIC: low middle income countries; PNG: Papua New Guinea; LA: left atrium; NYHA: New York Heart Association; PASP: pulmonary artery systolic pressure; RF: rheumatic fever; AF: atrial fibrillation.

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Declaration:

We declare no conflict of interest in the publication of this manuscript.

Contributions:

Conceptualisation, data collection and original manuscript was written by LBK. Proofread, edition was done by Zhu Ling. CYL, NT, and LCY proofread the manuscript. The final draft for publication was approved by all with consensus.

Acknowledgements:

This medical mission was supported by the National Heart Centre Singapore with funding and logistics was provided by Air Niugini and coordinated by Alice Phang, International Business Relations officer.

We also acknowledge the Port Moresby General Hospital management, their staff and patients in the success of this operation.