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Original research
Factors associated with poor outcomes after congenital heart surgery in low-resource setting in Pakistan: insight from the IQIC Registry – a descriptive analysis
  1. Shumaila Furnaz,
  2. Abdul Sattar Shaikh,
  3. Rayyan Qureshi,
  4. Subhani Fatima,
  5. Sohail Khan Bangash,
  6. Musa Karim,
  7. Muneer Amanullah
  1. National Institute of Cardiovascular Diseases, Karachi, Pakistan
  1. Correspondence to Shumaila Furnaz; shumailafurnaz41{at}gmail.com

Abstract

Objective This study aimed to assess the International Quality Improvement Collaborative single-site data from a developing country to identify trends in outcomes and factors associated with poor outcomes.

Design Retrospective descriptive study.

Setting The National Institute of Cardiovascular Diseases, Karachi, Pakistan.

Participants Patients undergoing surgery for congenital heart disease (CHD).

Outcome measure Key factors were examined, including preoperative, procedural and demographic data, as well as surgical complications and outcomes. We identified risk factors for mortality, bacterial sepsis and 30-day mortality using multivariable logistic regression.

Results A total of 3367 CHD surgical cases were evaluated; of these, 59.4% (2001) were male and 82.8% (2787) were between the ages of 1 and 17 years. Only 0.2% (n=6) were infants (≤30 days) and 2.3% (n=77) were adults (≥18 years). The in-hospital mortality rate was 6.7% (n=224), and 4.4% (n=147) and 0.8% (n=27) had bacterial sepsis and surgical site infections, respectively. The 30-day status was known for 90.8% (n=3058) of the patients, of whom 91.6% (n=2800) were alive. On multivariable analysis, the adjusted OR for in-hospital mortality was 0.40 (0.29–0.56) for teenagers compared with infancy/childhood and 1.95 (1.45–2.61) for patients with oxygen saturation <85%. Compared with Risk Adjustment for Congenital Heart Surgery (RACHS-1) risk category 1, the adjusted OR for in-hospital mortality was 1.78 (1.1–2.87) for RACHS-1 risk category 3 and 2.92 (1.03–8.31) for categories 4–6. The adjusted OR for 30-day mortality was 0.40 (0.30–0.55) for teenagers and 1.52 (1.16–1.98) for patients with oxygen saturation <85%. The 30-day mortality rate was significantly higher in RACHS-1 risk category 3 compared with category 1, with an adjusted OR of 1.64 (1.06–2.55).

Conclusions We observed a high prevalence of postoperative infections and mortality, especially for high-risk procedures, according to RACHS-1 risk category, in infancy/childhood, in children with genetic syndrome or those with low oxygen saturation (<85%).

  • congenital heart disease
  • echocardiography
  • paediatric cardiac surgery

Data availability statement

Data are available upon reasonable request.

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STRENGTHS AND LIMITATIONS OF THIS STUDY

  • This study represents a comprehensive analysis of the largest cohort of patients with congenital heart disease in Pakistan, underscoring its significance in the context of this region.

  • It is important to note that this study’s limitations stem from its single-centre and single geographical focus, which may impact the broader applicability of its findings.

  • The International Quality Improvement Collaborative Registry primarily serves as a tool for assessing quality; consequently, it does not capture detailed data regarding procedure-related information and the underlying causes, making it challenging to assess the impact of these factors on outcomes and complications.

Introduction

Congenital heart disease (CHD) has become a significant public health concern worldwide.1 With the world population nearing eight billion, the demand for CHD centres has increased.2 3 According to the estimates of the Global Burden of Disease (GBD) study, the age-standardised prevalence rate of CHD was 163.9 per 100 000 for the South Asian region in 2017.4 According to GBD estimates for 2019, Nigeria, China, Pakistan and India account for 39.7% of global deaths due to CHD, with 11 000 (7000–19 000) deaths in Pakistan.5 Newly emerging institutions in developing countries face a significant number of patients with untreated CHD, limited material and human resources, insufficient government support and a lack of health insurance.

Moreover, the paediatric age group constitutes a significant portion of the population in developing countries and the prevalence of CHD in this group remains unknown.6 Juvenile heart surgery complications commonly include postoperative infections, with rates ranging from 15% to 30%, which may be even higher in developing countries, where most data are not verified.7–10 Infections have a significant impact on the postoperative period as they are associated with higher morbidity, death, antibiotic use and longer hours in the intensive care unit (ICU).11–13

Although risk-adjusted mortality reductions have already been recorded, the primary goal is to reduce overall postoperative mortality in patients undergoing congenital heart surgery in underdeveloped nations.14 Pakistan is the second largest country in the region, and presumably there are only four hospitals that can care for patients with CHD or perform surgery on patients with CHD.15

This article focuses on postoperative infections such as bacterial sepsis and surgical site infection (SSI) as major causes of mortality and in-hospital mortality. The impact of these infections on the likelihood of death following congenital heart surgery in underdeveloped nations is of particular significance. Our aims are to develop an understanding of the trends in various postsurgical complications of paediatric cardiac surgery as well as to explore the different risk factors that may influence these outcomes.

Methods

Study population

The study population consisted of consecutive patients undergoing congenital heart surgery at the National Institute of Cardiovascular Diseases (NICVD), Karachi, Pakistan, from May 2017 to September 2022, cases that were registered in the International Quality Improvement Collaborative (IQIC) Registry. Patients with incomplete information regarding their infection status were excluded.

Data collection process

This study is a retrospective analysis of the prospectively collected IQIC data for a single site. Non-probability consecutive sampling was used as the sampling strategy. Following appropriate individual verification, deidentified data were uploaded into the central data repository using a digital platform in accordance with the IQIC data protocol. The demographics of each patient, the surgical procedure(s) performed, surgical history, preoperative status and clinical outcomes were all documented. Additionally, status with regard to preoperative balloon atrioseptostomy, resuscitation, inotrope therapy and invasive ventilation was also recorded. Data underwent source verification through a series of inspection visits conducted between 2017 and 2022. As per the IQIC functional protocol, multidisciplinary teams and officials from non-governmental organisations conducted data source verification using a minimum 10% sample of cases from our site. The data audit determined the comprehensiveness and accuracy of the data for inclusion in the overall results. Consent for participation in the registry was obtained from all patients/caretakers.

Clinical outcomes

The main outcomes of this analysis are in-hospital mortality, any major infection/bacterial sepsis and 30-day mortality.

Assessment and diagnosis

All CHD diagnoses and the presence of rheumatic heart disease were confirmed with preoperative echocardiography. The surgical risk of the procedure was categorised using the Risk Adjustment for Congenital Heart Surgery (RACHS-1) risk category.16

Bacterial sepsis was defined as any two of the clinical signs of sepsis with a positive blood culture. The clinical signs included hypothermia or fever, hypotension, tachycardia, tachypnoea, leucopenia or leucocytosis. SSI was defined and subclassified as deep incisional SSI or superficial incisional SSI as per the official criteria of the Centers for Disease Control and Prevention, and if the clinical indicators suggested significant infection then positive cultures were not required.17 SSI was specific to the wounds, whereas bacterial sepsis can originate from various sources, not limited to wounds, and may manifest as a concurrent diagnosis. The death that occurred during the postoperative hospital stay prior to discharge was labelled as in-hospital mortality.

Statistical analysis

Participants were interviewed using a standardised questionnaire. The data were then loaded into SPSS V.21 to calculate frequency, percentages and mean±SD. Our study sample consists of patients ranging from infancy to adulthood; hence, most of the clinical parameters, especially anthropological parameters such as height and weight, are not normally distributed, and mean (SD) can be misleading in these situations; hence, the median and IQR are reported. Statistical significance tests such as χ2 and one-way analysis of variance were used to compare the clinical data among the age-based categorisation of patients. Multivariable stepwise (backward conditional) logistic regression analysis was performed to determine the multivariable association, and the OR and corresponding 95% CI were computed. The data were then displayed in the form of graphs and tables.

Patient and public involvement

None.

Results

A total of 3367 CHD surgical cases were registered in the IQIC database from the NICVD in Karachi, Pakistan, covering the period from May 2017 to September 2022. Among these cases, 59.4% (2001) were male and 82.8% (2787) were between the ages of 1 and 17 years. Infants (≤30 days) accounted for only 0.2% (n=6) of the cases, while adults (≥18 years) constituted 2.3% (n=77) of the total. Based on the RACHS-1 risk categorisation, 16.8% (n=567) of the procedures fell into category 1, 58% (n=1953) into category 2, 21.7% (n=732) into category 3, 0.9% (n=30) into category 4 and 0.2% (n=7) into category 5 (table 1).

Table 1

Distribution of demographic and clinical characteristics and RACHS-1 risk category for the surgical procedure stratified by age of the patient at the time of surgery

The overall in-hospital death rate was found to be 6.7% (n=224), and there was a significant decline in mortality with increase in age from infancy to adulthood (p<0.001). Additionally, bacterial sepsis was reported in 4.4% (n=147) of the patients, while SSIs were reported in 0.8% (n=27) (table 2). It is worth noting that a lower number of surgical procedures and a higher mortality rate were observed in year 2020 (figure 1), likely influenced by the COVID-19 pandemic. Similarly, the highest rate of bacterial sepsis was observed in year 2019 (figure 1).

Figure 1

Trend of in-hospital mortality rate, sepsis rate and number of procedures by calendar year. *May–December 2017. **January–September 2022. COVID-19 era.

Table 2

Distribution of complications, infection and outcomes (in-hospital and 30-day) after surgical procedure stratified by age of the patient at the time of surgery

A linear increase has been observed in the in-hospital mortality rate in relation to the RACHS-1 risk category. The mortality rate was found to be 4.6% for RACHS-1 risk category 1 and 13.5% for RACHS-1 risk category ≥4 (p=0.019) (figure 2).

Figure 2

Trend of in-hospital mortality rate and number of procedures by RACHS-1 risk category. RACHS-1, Risk Adjustment for Congenital Heart Surgery.

The need for surgery due to bleeding was observed in 11.9% (176/1482) of cases, while other complications were reported in 16.3% (241/1482). The median ventilator time was 6 (4–11) hours, and the median ICU stay was 39 (32–50) hours. The 30-day status was known for 90.8% (n=3058) of the patients, with 91.6% (n=2800) of these patients being alive.

In the multivariable analysis, when compared with infancy/childhood, teenagers had a lower risk of in-hospital mortality, with an adjusted OR of 0.38 (95% CI 0.28 to 0.52). Conversely, patients with oxygen saturation levels below 85% had a higher in-hospital mortality rate, with an adjusted OR of 1.98 (95% CI 1.48 to 2.65). Furthermore, the in-hospital mortality rate was significantly higher in RACHS-1 risk categories 3 and 4–6, compared with category 1, with adjusted ORs of 1.81 (95% CI 1.12 to 2.92) and 2.98 (95% CI 1.05 to 8.43), respectively (table 3).

Table 3

Multivariable associations with in-hospital mortality, bacterial sepsis and 30-day mortality

Similarly, the risk of bacterial sepsis was lower for teenagers, with an adjusted OR of 0.50 (95% CI 0.34 to 0.74) compared with infancy/childhood (table 3).

Additionally, the risk of 30-day mortality was lower for teenagers, with an adjusted OR of 0.4 (95% CI 0.29 to 0.53) compared with infancy/childhood. Conversely, it was significantly higher for patients with oxygen saturation levels below 85%, with an adjusted OR of 1.52 (95% CI 1.17 to 1.98) (table 3).

Patients with bacterial sepsis were found to be at an increased risk of in-hospital and 30-day mortality with a risk ratio of 13.30 (95% CI 9.24 to 19.14; p<0.001) and 10.88 (95% CI 7.61 to 15.57; p<0.001), respectively.

Discussion

This study investigated the in-hospital mortality and postoperative infections in 3367 CHD surgical cases registered in the IQIC database at the NICVD in Karachi. The objective was to identify potential causes that may contribute to adverse outcomes in these procedures. By using the IQIC database, which has identified numerous factors that healthcare centres must investigate before conducting surgeries, we identified several elements that could significantly contribute to poorer outcomes. Our primary goal was to systematically record and investigate these elements in accordance with the framework provided by IQIC, aiming to gather data that can help interpret their prevalence at hospitals in low-income and middle-income countries (LMICs), like the NICVD itself. Understanding the prevalence of these risk factors in relation to surgical outcomes can help explain any potential relationships and the extent of their influence.

After the surgeries, complications such as postoperative infections and mortality remain concerning events that necessitate investigation. Our multivariable analysis identified several risk factors, including young age, prematurity, higher surgical complexity and associated non-cardiac abnormalities. Furthermore, medical illness, preoperative procedures and repeated surgery for bleeding were found to independently elevate the risk of sepsis.7 8 Similar to our findings, in a study by Khan et al,18 age, being malnourished, major chromosomal abnormality, oxygen saturation <85% and RACHS-1 risk category 3 or higher were found to be associated with an increased risk of major infection and 30-day mortality. The risk factors for the outcomes discussed in this study in LMICs with limited healthcare resources are similar to those discovered following juvenile heart surgery in developed countries.7 8 19

At the NICVD, the study revealed an in-hospital mortality rate of 6.7% (n=224), with 4.4% (n=147) of the patients experiencing bacterial sepsis and 0.8% (n=27) developing SSIs. Notably, teenagers (aged 1–17) exhibited a lower risk of in-hospital mortality and bacterial sepsis compared with infants and young children (aged less than 30 days to 1 year). Patients with oxygen saturation below 85% had a higher in-hospital mortality rate, but their risk of bacterial sepsis was significantly elevated. Furthermore, the in-hospital mortality rate progressively increased in alignment with the higher RACHS-1 risk categories (3 and 4–6) compared with category 1. The presence of genetic syndromes also significantly increased the risk of bacterial infections. Lastly, the 30-day mortality rate was notably higher in RACHS-1 risk category 3 compared with category 1. However, in other developing countries, the precise ramifications of these risk factors may be substantially greater. A similar positive association between RACHS-1 risk categories and an increased mortality rate has been reported by various studies. Khan et al18 reported 30-day mortality rates of 0%, 4.8%, 20.8% and 22.2% and major infection rates of 12.3%, 17.8%, 26.2% and 22.2% for RACHS-1 risk categories 1, 2, 3 and 4, respectively. Cavalcante et al20 reported hospital mortality rates of 1.8%, 5.5%, 14.9% and 32.5% for RACHS-1 risk categories 1, 2, 3 and 4, respectively. Another study by Cavalcanti et al21 showed in-hospital mortality rates of 1.3%, 11.4%, 27.3% and 50% for RACHS-1 risk categories 1, 2, 3 and 4, respectively.

In congenital heart surgery, mortality can result from several other factors other than infections, including bleeding, postoperative arrhythmias and postoperative heart block.22 Bleeding can occur due to the intricate nature of cardiac surgery and may necessitate transfusions or re-exploration to control haemorrhage. Postoperative arrhythmias may disrupt the heart’s rhythm, potentially causing life-threatening complications, and often require intervention with medications or electrical therapy. Postoperative heart block, a disruption in the electrical conduction system of the heart, can also lead to significant mortality if not promptly managed, often necessitating placement of a pacemaker.

Surgical complications during congenital heart surgery may include dissection of cardiac structures, perforation of the heart or major blood vessels, and inappropriate ligation of vital structures. These complications can pose serious risks and require immediate recognition and corrective action to prevent adverse outcomes. Skilled surgical techniques, vigilant monitoring and meticulous attention to detail are essential in mitigating these potential complications.23 In congenital heart surgery, common measures of myocardial protection include use of cardioplegia to arrest the heart, hypothermia to reduce metabolic demands and administration of oxygenated blood through a cardiopulmonary bypass machine, which ensures adequate oxygen supply to the heart while the surgical repair or correction is performed.24

With increased access to basic healthcare and rising human development indices in various parts of the world, a significant increase in the number and parallel proportions of neonates requiring surgery for CHD can be expected in the coming decades.8 Similarly, as congenital heart surgery facilities become more advanced, surgical intricacy is projected to increase.

In our study, bacterial sepsis was found to be associated with an increased mortality rate, with a risk ratio of 13.30 (95% CI 9.24 to 19.14; p<0.001) for in-hospital mortality and 10.88 (95% CI 7.61 to 15.57; p<0.001) for 30-day mortality. To ensure comprehensive paediatric cardiac care, programmes should prioritise constructing effective infection prevention and control systems to reduce the impact of these outcomes on postoperative mortality. Alp and Damani25 have proposed possible solutions to prevent infection after surgery in the ICU in low-resource economies and how adapting these techniques can yield substantial benefits. Singh et al26 state that incorporating infection control practice training is an effective approach to minimise healthcare-associated infections and their consequences following heart surgery.

Efforts like the IQIC involvement are critical as postoperative infections and in-hospital mortality have a significant impact on CHD surgery utilisation of resources and clinical outcomes.18 27 The IQIC serves as a framework for a comprehensive data harvesting structure, a self-evaluation data outline and a standard enhancement instructional strategy.18 27 It promotes team-based engagement and collaboration, as well as cooperative learning to transmit standard procedures from one centre to the next. Sites can exchange effective techniques and challenges with one another, as well as track their progress. Although it is challenging to verify whether IQIC operations caused a reduction in infections and postoperative mortality, the sequential association and focus on instituting evidence-based strategies to minimise these outcomes make the association credible and provide a prospective propagation strategy towards other resource-poor environments.18 27

This study represents a comprehensive analysis of the largest cohort of patients with CHD in Pakistan, underscoring its significance in the context of this region. It is important to note that this study’s limitations stem from its single-centre and single geographical focus, which may impact the broader applicability of its findings. The IQIC Registry primarily serves as a tool for assessing quality; consequently, it does not capture detailed data regarding procedure-related information and the underlying causes, making it challenging to assess the impact of these factors on outcomes and complications.

Conclusion

The data we analysed, obtained in collaboration with the IQIC, revealed a high prevalence of postoperative infections and their significant impact on morbidity and mortality. Considering the anticipated increase in the number of juvenile heart procedures in developing countries, we identified high-risk populations in which infection prevention strategies should be targeted. Implementing preventative measures is essential as these can help developing countries conserve a significant portion of their healthcare expenditure, which could be better used elsewhere. Stressing the importance of collaboration and cooperation in learning and sharing knowledge becomes paramount when it comes to prevention. These aspects are crucial to fostering innovation and enhancing the quality of care provided in resource-constrained settings.

Data availability statement

Data are available upon reasonable request.

Ethics statements

Patient consent for publication

Ethics approval

This IQIC Registry was approved by the ethical review committee of the National Institute of Cardiovascular Diseases (NICVD), Karachi, Pakistan. Verbal informed consent for participation in the study and publication of data was obtained from all patients while maintaining confidentiality and anonymity. Due to the observational nature of the study, the ERC waived the written consent and approved the verbal consent.

Acknowledgments

The authors wish to acknowledge the support of the staff members of the Clinical Research Department of the National Institute of Cardiovascular Diseases (NICVD), Karachi, Pakistan.

References

Footnotes

  • Contributors SFu, ASS, RQ, SFa, SKB, MK and MA contributed to the concept and design of the study. SFu, ASS, RQ, SFa, SKB, MK and MA contributed to the analysis and interpretation of data. SFu and MK collected data and drafted the manuscript, and SFu, ASS and MK critically analysed for content. All authors approved the final draft of the manuscript. SFu, ASS, and MA acts as guarantor, takes full responsibility for the work and/or the conduct of the study, had access to the data, and controlled the decision to publish.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient and public involvement None

  • Provenance and peer review Not commissioned; externally peer reviewed.