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Three Part Question

In [patients with sickle cell disease and cardiac disorder] does [cardiac surgery] increase [mortality and sickle cell related morbidities]?

Clinical Scenario

A 50-year-old female from Eastern province of Saudi Arabia presented with symptomatic severe aortic stenosis. She was known to have sickle cell trait(HbSS), with hardly any vaso-occlusive crisis. A transthoracic echocardiogram demonstrated severe Aortic stenosis and moderate LV systolic dysfunction. Her coronaries were normal on angiogram and hence it was decided to proceed with surgical Aortic valve replacement. The patient wanted to know if cardiac surgery could increase her mortality and if there was any alternative, including Transcatheter aortic valve replacement.

Search Strategy

Databases: PubMed 1970 to December 2019 using the OVID interface was used. A search for (exp Cardiac Surgery/OR exp Specialties, Surgical/ OR Surgery.mp) AND (exp Sickle Cell Disease/) in humans were made.

Search Outcome

A total of 138 papers were found using the reported search. Of these, 6 papers were identified to provide the best available evidence to answer the clinical question. These are presented in Table 1.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
El Mehdi Moutaouekkil, Abdelmalek Najib, Rida Ajaja, Moha Arji, Anas Slaoui 2015 Morocco	African homozygous sickle cell disease( Hb SS ) females who underwent mitral valve surgeries	The patients received exchange transfusion before surgery. Five to six blood bags were sufficient on each patient to decrease HbS concentration to about 30% and to increase hematocrit.	30 day Mortality rate - 0 %	SCD related complications - 0%	Case series Small number
Yousafzai et al 2010 Saudi Arabia	9-year-period Included both adult and paediatric patients 47 patients in total	Retrospective observational study Level 3	30 day Mortality rate - 2.1 %	Hemorrhage - 6.4%	Only 4 year follow up of patients
Khaled E Al-Ebrahim 2008 Saudi Arabia	Patients with sickle cell disease who underwent double valve replacements	Case series Level 4	30 day Mortality rate - 0 %	SCD related complications - 0%	Case series and hence small number
H M J Harban et al United Kingdom	Paediatric patients who required heart surgeries involving cardiopulmonary bypass	Case Series Level 4	30 day Mortality rate - 0 %	SCD related complications - 0%	Case Series
Metras et al 1982 Ivory Coast	The patients in this study were 19 black Africans aged 3-40 years (mean 18-6 years). 17 had sickle-cell trait and two a more complex sickling disorder-one SC haemoglobinopathy and one beta-thalassaemia sickle-cell disease, and was compared to 29 controls	Level 3 -Observational study	30 day Mortality rate - 13%	Average length of hospital stay - 16	No long term follow up.

Comment(s)

Of the 6 papers selected, two were matched pair case-control studies, a retrospective study and the remaining three were case series. We did not find any prospective, randomized trials due to rarity of the condition. From the above-mentioned studies, a total of 107 patients, previously diagnosed with sickle cell trait or SCD, were operated upon at different cardiac centres with good outcome. Only three mortalities were reported overall with minimal SCD related complications including sickling crisis. The proposed management adopted from these studies are tabulated (Table 2)[11]–[13] Some of the experienced centres adopted strategies to prevent SCD related crisis which included decreasing the HbS concentration[12], [14], increasing the haematocrit, increasing the oxygen saturation and maintaining the pH and thereby preventing the acidosis. This review also included paediatric population in three of reported studies. Even though these cohort required more blood transfusion and longer length of hospital stay, surgeries like double valve replacements and congenital cardiac surgeries with this haemoglobinopathy, without inducing vaso-occlusive crises,major organ complications or mortality were reported.

Clinical Bottom Line

With reduction of HbS concentration and avoidance of precipitating factors, cardiac surgeries involving cardiopulmonary bypass can be performed for such patients with acceptable outcomes[11,15].

References

1. El Mehdi Moutaouekkil, Abdelmalek Najib, Rida Ajaja, Moha Arji, Anas Slaoui Heart Valve Surgery in Patients With Homozygous Sickle Cell Disease: A Management Strategy Ann Card Anaesth , 18 (3), 361-6 2015
2. Frank Edwin et al Hypothermic Cardiopulmonary Bypass Without Exchange Transfusion in Sickle-Cell Patients: A Matched-Pair Analysis Interact Cardiovasc Thorac Surg Nov 14;19 (5), 771-6
3. Yousufzai et al Open Heart Surgery in Patients With Sickle Cell Hemoglobinopathy Circulation Jan 2010; 121 (1), 14-9
4. Khaled E Al-Ebrahim Cardiac Surgery and Sickle Cell Disease Asian Cardiovasc Thorac Ann Dec 2008; 16 (6), 479-82
5. F M J Harban, P Connor, R Crook, R Bingham Cardiopulmonary Bypass for Surgical Correction of Congenital Heart Disease in Children With Sickle Cell Disease: A Case Series Anaesthesia Jun 2008; 63 (6), 648-51
6. Metras et al Open-heart Surgery in Sickle-Cell Haemoglobinopathies: Report of 15 Cases Thorax Jul 1982; 37 (7), 486-91