Year : 2013  |  Volume : 16  |  Issue : 3  |  Page : 215--217

Cardiac surgery in a patient with severe thrombocytopenia: How low is too low?


Ahmed Ashoub1, Suresh Lakshmanan2, Heyman Luckraz1,  
1 Department of Cardiothoracic Surgery, Heart and Lung Centre, Wolverhampton, WV10 0QP, United Kingdom
2 Department of Cardiothoracic Anaesthesiology, Heart and Lung Centre, Wolverhampton, WV10 0QP, United Kingdom

Correspondence Address:
Heyman Luckraz
Heart and Lung Centre Wolverhampton, WV10 0QP
United Kingdom

Abstract

Platelets play a very important role in hemostasis, especially after cardiac surgery. Excessive bleeding after such surgery may lead to increased need for transfusion and its incumbent increase in post-operative morbidity and mortality. Although most cardiac surgeons will offer a surgical option to a patient with moderate thrombocytopenia (platelet count around 70 × 10 9 /L), successful cardiac surgery has not been reported in patients with significantly lower platelets counts (less than 40 × 10 9 /L). We report a case of severe thrombocytopenia (19 × 10 9 /L) where coronary artery bypass grafting was performed with minimal blood loss post-operatively, discuss the patient«SQ»s management and provide insights while dealing with such patients.



How to cite this article:
Ashoub A, Lakshmanan S, Luckraz H. Cardiac surgery in a patient with severe thrombocytopenia: How low is too low?.Ann Card Anaesth 2013;16:215-217


How to cite this URL:
Ashoub A, Lakshmanan S, Luckraz H. Cardiac surgery in a patient with severe thrombocytopenia: How low is too low?. Ann Card Anaesth [serial online] 2013 [cited 2020 Jan 29 ];16:215-217
Available from: http://www.annals.in/text.asp?2013/16/3/215/114258


Full Text

 Introduction



Platelets play a pivotal role in the control of post-operative bleeding by (a) forming a platelet plug and (b) degranulating and releasing serotonin (causing vasoconstriction), thromboxane A2 (involved in vasospasm and attracting more platelets) and adenosine diphosphate (attracting more platelets). Patients with platelet count of less than 150 × 10 9 /L are considered thrombocytopenic and when they undergo cardiac surgery, they can be at high risk of bleeding complications. In general, most cardiac surgeons will still be willing to go ahead with surgery when patient have a mild to moderate thrombocytopenia (platelets: 70-149 × 10 9 /L). Most of the reports in the literature of cardiac surgical procedures in patients with low platelets count have been in the setting of idiopathic thrombocytopenic purpura (ITP) and heparin induced thrombocytopenia (HIT). [1],[2] We discuss the management of a patient who was severely thrombocytopenic (platelet count: 19 × 10 9 /L) undergoing coronary artery bypass grafting (CABG).

 Case Report



A 65-year-old gentleman was referred for CABG with 6 months history of angina (Canadian Cardiovascular Society [CCS] Class 3) and shortness of breath (New York Heart Association [NYHA] Class II]. Coronary angiography revealed a blocked right coronary artery and significant stenoses in the left anterior descending, and first and second obtuse marginal arteries (OM1 and OM2). European system for cardiac operative risk evaluation was 2. Significant past medical history included recently diagnosed thrombocytopenia possibly owing to ITP. He was treated with steroids, azathioprine and immunoglobulin, but his platelet counts worsened during treatment as did his angina. Following bone marrow biopsies a revised diagnosis of myelodysplastic syndrome (MDS) was made and he was referred for urgent surgery. He was initially reviewed by the Interventional Cardiologist, but owing to the low platelet counts and the need for multiple stents and the unsafe use of anti-platelets drugs, he was turned down for percutaneous coronary intervention (PCI). Moreover, the OM2 was rather posterior, and off-pump coronary-artery-bypass (OPCAB) to that vessel was deemed difficult by the operating surgeon, which meant that OPCAB might leave the patient with incomplete revascularization. At that point, his platelet counts were 19 × 10 9 /L. He was also anaemic with a haemoglobin level of 11 g/dl. Pre-operative international normalized ratio (INR) was 0.9, and activated partial thromboplastin time (aPTT) was 29 sec (23-30 sec).

On the day of surgery, the patient was transfused with a unit of platelets (six pooled platelets following apheresis of donor whole blood) two hours prior to surgery. Following the initiation of surgery and during the left internal mammary artery harvesting another unit of platelets was transfused in an attempt to reduce blood loss before cardiopulmonary bypass (CPB). Intra-operative platelet count after transfusion showed an improved count to 52 × 10 9 /L. Intra-operatively, he was also, given 5 g of tranexamic acid. The intra-operative coagulation management was as per our unit protocol and included activated clotting time while on CPB and thrombo-elastography (TEG) post-heparin reversal with protamine. He underwent CABG × 4 grafts with a CPB time of 90 min. TEG post termination of CPB and after reversal of protamine indicated a coagulopathy for which two pools of platelets and 4 units of fresh frozen plasma were transfused. Following transfer to cardiovascular intensive care unit, he did not require any further blood or blood product transfusion. The total chest drain over the ensuing 24 h was 710 ml. The INR (1.2) and aPTT 28 sec on first post-operative day were within normal limits. His post-operative course was very uneventful and was discharged home on day 5 post-operative with a platelet count of 47 × 10 9 /L. He has as yet not had any anti-platelet drug. He is now nearly 3 years post-operative and is in CCS Class 0 and NYHA Class I. Unfortunately, he has not responded well to his MDS treatment and his most recent platelet count was 2 × 10 9 /L [Table 1]. He has not experienced any issues with pericardial collection or mediastinal bleeding.{Table 1}

 Discussion



Several factors have been associated with thrombocytopenia [Table 2]. A pre-operative diagnosis of ITP is present in 0.2% patients [1] while HIT may be present in up to 1% [2] of patients undergoing cardiac surgery. Our patient was diagnosed with a MDS, which can be associated with 5q or 20q deletions. After recovering from his CABG, he was treated with azacytidine, but showed minimal response. He is now nearly 3 years following his CABG and his last platelet count was 2 × 10 9 /L and he was treated with platelet transfusion and romiplostim.{Table 2}

Pre-operative thrombocytopenia could be associated with an increase in the bleeding risk. Excessive bleeding after CPB may lead to increased mortality, morbidity, transfusion requirements and re-intervention. [3],[4] In a recently described case by Chowdhry et al., the patient was diagnosed with ITP and responded well to pre-operative oral prednisolone and intravenous immunoglobulin. [4] However, following an uneventful surgical procedure, patient was re-admitted due to pericardial tamponade, which required drainage and unfortunately patient succumbed. Around 50 patients with ITP undergoing cardiac surgery have been reported. [1] However, most of these patients were in the mild thrombocytopenic category with a mean pre-operative platelet count of 126 × 10 9 /L. In the same report, Jubelirer et al., commented that only 40% of these patients required a platelet transfusion while the median post-operative blood loss was 1,346 ml. Russo et al., [5] compared the outcome of two modes of revascularization (CABG vs. PCI) in patients with ITP. They identified 47 cases with ITP where a coronary intervention was carried out and concluded that both modalities (CABG or PCI) are feasible, but with higher peri-procedural bleeding risk in both groups. As for the pre-operative HIT thrombocytopenic group, the report suggested that there was no significant increase in mortality. [2] There have also been some reports where splenectomy was performed in an attempt to improve platelet counts pre-cardiac surgery and also the use of off-pump cardiac surgery to reduce post-operative bleeding. [1],[6] The patient described in the present report did not fit in either the ITP or the HIT group, but shared the thrombocytopenic element of these groups. In fact, he was severely thrombocytopenic at the time of his cardiac surgery and remains so to date with minimal response to any of the therapeutic measures that have been tried. Our experience of this patient suggest that safe and successful cardiac surgery is feasible in this group of patients despite a very low platelet count (< 20 × 10 9 /L). We optimized intra-operative platelet count which might have reduced intra-operative blood loss. In this group of patients, coagulopathy should be promptly treated in the immediate post-operative phase and management could be guided by point-of-care TEG analysis and may be in the future by the more reliable point-of-care platelet function assessment kits.

To summarize, a low platelet count (< 50 × 10 9 /L) per se should not exclude a patient from undergoing CABG. The cause of the thrombocytopenia should be investigated and if possible treatment initiated prior to cardiac surgery. However, if patient fails to respond to the treatment and cardiac surgery is still necessary, then after appropriate assessment, patients with low pre-operative platelet count can undergo surgery in specialized units with appropriate monitoring and expertise.

References

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3Vivacqua A, Koch CG, Yousuf AM, Nowicki ER, Houghtaling PL, Blackstone EH, et al. Morbidity of bleeding after cardiac surgery: Is it blood transfusion, reoperation for bleeding, or both? Ann Thorac Surg 2011;91:1780-90.
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