Bleeding Risks With Cardiac Disease

Cardiac Disease

Cardiac disease can result in congestive heart failure and congestive hepatopathy (cardiac cirrhosis). This is associated with a decrease in hepatic synthetic function, thrombocytopenia, and splenomegaly (see Chapter 119 on Liver Disease). Specific myocardial diseases are rare but can occur. Amyloid infiltration can cause myocardial dysfunction and may be associated with a decrease in factor X and dysfibrinogenemia. Although these may cause a coagulopathy and abnormal coagulation testing, amyloidosis can also cause impaired left ventricular function, leading to aneurysm formation and mural thrombi; these may require anticoagulation.

Cyanotic heart diseases may lead to polycythemia. Increased hematocrit can cause rheologic sludging issues while also lowering production of clotting factors. More commonly, the increased hematocrit may cause a factitious elevation of the prothrombin time (PT) and partial thromboplastin time (PTT) as a result of excessive citrate:plasma ratio in the tube used for testing. This laboratory artifact can be overcome by drawing the blood into a syringe containing less citrate to compensate for the decreased plasma.

Certain cardiac conditions such as a ventricular septal defect (VSD), severe aortic or pulmonic stenosis, and some artificial valves may cause vascular turbulence and contribute to an acquired von Willebrand syndrome (AVWS, see Chapter 109 ). In this condition, there is loss of the high-molecular-weight multimers secondary to a shearing effect on the large von Willebrand protein. This loss causes an inappropriately low VWF activity compared with the VWF antigen level with a laboratory picture similar to congenital type 2A VWD. The severity of the AVWS correlates well with the severity of the stenosis. Paravalvular leaks have also been reported to induce the same hemostatic phenomenon. Correction of the VSD or abnormal heart valve will correct the AVWS.

The high shear rates can also lead to coagulopathies by increasing hemolysis. The increased hemolysis may lead to severe anemia and an increased bleeding diathesis while the free hemoglobin may cause an increase in thrombotic potential. If the shear stress is sufficient, thrombocytopenia and thrombocytopathies can complicate an already complicated situation.