Heparin Induced Thrombocytopenia and Cardiac Surgery: A Comprehensive Review

Abstract

Heparin induced thrombocytopenia presents as an underdiagnosed condition with life threatening thrombotic complications. The incidence in cardiac surgery patients is dependent on several factors and appeared to be greater in procedures that involve the use of intraaortic balloon pump. Clinical diagnosis is particularly challenging in cardiac surgery patients due to the natural occurrence of post-operative thrombocytopenia. High index of suspicion is key factor to establish adequate treatment and prevent the occurrence of thrombotic complications, such as saphenous vein graft occlusion, pulmonary embolism and myocardial infarction, which lead to substantially increased mortality rates. The 4T's assessment point system was designed in order to evaluate the likelihood of occurrence of the condition based on clinical presentation; however, serotonin release assay represents the gold standard to reach diagnosis. Treatment of heparin induced thrombocytopenia involves cessation of unfractionated and fractionated heparin, and the instauration of therapy with direct thrombin inhibitors. Among all direct thrombin inhibitors agents, Bivaluridin is emerging as a potential first line of treatment based on its benefits of a short half-life and enzymatic elimination.

Comparative Analysis of the Suspected Heparin‐Induced Thrombocytopenia Level in Korea

“…These findings call for medical teams to monitor platelet counts more closely, to ensure the early discovery of HIT. In addition, it is important to conduct a platelet count in the day 1 – day 5 period, as in 11.6% of the cases, a >50% decrease in platelet count in day 1 – day 4 was observed, which could indicate HIT type I (non‐immune heparin‐associated thrombocytopenia) .…”

Thrombocytopenia After Transcatheter Valvein- Valve Implantation: Prognostic Marker or Mere Finding?

“…The unavoidable hemodilution that succeeds, the sheer stress to the platelets, by roller or centrifugal pumps, and extracorporeal plastic tubing interaction, have been commonly charged with causing their ultimate destruction [ 12 , 19 ] . Other well-established factors associated with thrombocytopenia in cardiac surgery are the use of intra-aortic balloon pumps (IABP), sepsis and drug-related, mainly heparin-induced thrombocytopenia (HIT), a rare phenomenon with incidence around 1% [ 11 - 13 ] .…”

“…Considering cardiac surgery patients, thrombocytopenia is an extremely frequent finding, varying from 35% to 65% of all cases [ 10 ] , and patients after percutaneous coronary interventions (PCI) are also prone to develop major thrombocytopenia, i.e . <100.000/µL, in 2.4-9.2% of cases [ 11 - 13 ] .…”

Plasmapheresis, intravenous immunoglobulin and fondaparinux treatment in heparin-induced thrombocytopenia after aortic and mitral valve replacement

“…[1,5,6] Suspecting HIT is the first step in diagnosis of the disease in cardiac surgical patients. [7] Taking into account for the other causes that may lead to drop in platelets, clinican should suspect for HIT in the findings which are unexplained thrombocytopenia, venous or arterial thrombosis in the presence of thrombocytopenia, necrotic skin lesions at heparin injection sites and acute anaphylactoid reactions after IV boluses of heparin. [7] Unlike cases with previous history of HIT, it can be more challenging to diagnose and establish a standard protocol for those with postoperative worsening of hemodynamic parameters.…”