Risk factors for thrombogenesis have been described traditionally by the so-called “Virchow’s triad” consisting of stasis, endothelial damage, and hypercoagulability.Reference Stokman, Nandra and Richard Asinger 1 , Reference Egolum, Stover and Lenihan 2 Intracardiac thrombogenesis is seen most frequently following acute anterior myocardial infarction and dilated cardiomyopathy; moreover, intracardiac thrombi may also develop in the presence of hypercoagulable states such pregnancy, malignancy, protein-C and protein-S deficiency, infectious diseases including septic shock, and inflammatory conditions including ulcerative colitis, Behçet’s disease, and as an adverse effect to medications.Reference Stokman, Nandra and Richard Asinger 1 , Reference Yamamoto, Ikeda, Furuhashi, Irokawa, Nakayama and Shimada 3 – Reference Oeser, Andreas, Rath, Habertheuer and Kocher 8
Thrombosis is a well-known complication of inflammatory bowel diseases, including Crohn’s disease and ulcerative colitis. The overall incidence of thrombotic events in patients with inflammatory bowel disease is estimated to be 1–8%, which is approximately threefold greater than that of the general population.Reference Giannotta, Tapete, Emmi, Silvestri and Milla 9 , Reference Freeman 10 Thrombosis most commonly occurs in the lower extremities, lungs, brain, and liver.Reference Giannotta, Tapete, Emmi, Silvestri and Milla 9 More than half of the thrombotic events occur during an exacerbation of inflammatory bowel disease.Reference Saleh 11 In parallel with this, the risk for thrombosis correlates with the disease activity of inflammatory bowel disease.Reference Urgesi, Zampaletta and Masini 12 Cases of spontaneous ventricular thrombosis also have been reported in patients with inflammatory bowel disease in the age range of 28–42 years.Reference Saleh 11 – Reference Koneru, Koshy, Sharp and Khalafallah 16 In all cases, the patients were asymptomatic, and ventricular thrombosis was detected as an incidental finding during an acute flare-up of inflammatory bowel disease. Except for one instance of right ventricular thrombosis, all other cases of ventricular thrombosis developed in the left ventricle. The patients were immediately treated with either a combination of ventricular thrombectomy and anticoagulation or with anticoagulation alone to prevent systemic embolisation of the thrombus. Early detection and intervention are critical for ventricular thrombosis as the rate of systemic embolisation is about 2–3%.Reference O’Sullivan and Eberli 17
The mechanism underlying thrombotic events in an acute exacerbation of inflammatory bowel disease is speculated to be cytokine production in the setting of chronic and systemic inflammation. Cytokine production initiates a cascade leading to a hypercoagulable state, massive platelet aggregation, and impaired fibrinolysis.Reference Giannotta, Tapete, Emmi, Silvestri and Milla 9 , Reference Bryant, Jairath, Curry and Travis 18 About 24% of patients do not receive appropriate thromboprophylaxis during acute flare-ups of inflammatory bowel disease.Reference Dwyer, Javed, Hair and Moore 19 A key factor contributing to the underutilisation of thromboprophylaxis is the lack of awareness of healthcare providers on the thrombotic risk associated with inflammatory bowel disease.Reference Papa, Gerardi, Marzo, Felice, Rapaccini and Gasbarrini 20 Another factor speculated to play a central role in the low rate of thromboprophylaxis utilisation in patients with inflammatory bowel disease is the misperception that patients with inflammatory bowel disease are more likely to develop bleeding as an adverse effect of the anticoagulant; however, the rate of bleeding was reported to be similar for patients with inflammatory bowel disease and for the general population.Reference Papa, Gerardi, Marzo, Felice, Rapaccini and Gasbarrini 20 It is our hope that this article increases awareness of the increased risk for thrombosis in this patient population and, thus, prompts clinicians to consider the use of thromboprophylaxis therapy in these patients during acute flare-ups.
In the light of the high thrombotic risk associated with this particular population, and its asymptomatic presentation, it would be advisable to have a low threshold for screening patients with an acute exacerbation of inflammatory bowel disease for possible ventricular thrombosis before discharge, especially if other risk factors are present. Among patients with inflammatory bowel disease additional risk factors for developing thrombi include obesity, dehydration, and malnutrition.Reference Giannotta, Tapete, Emmi, Silvestri and Milla 9 Diagnosis of ventricular thrombosis is typically made using imaging modalities including cardiovascular MRI, transesophageal echocardiography, transthoracic echocardiography, coronary angiography, and CT of the chest. Of these modalities, contrast-enhanced cardiovascular MRI is the current gold standard for diagnosing ventricular thrombus.Reference Habash and Vallurupalli 21 , Reference Weinsaft, Kim and Shah 22 Cardiovascular MRI is a non-invasive method of forming detailed images of structures, perfusion, and blood flow of the heart using magnetic fields and radio waves.Reference Attili, Schuster, Nagel, Reiber and van der Geest 23 Late gadolinium enhancement using contrast-enhanced cardiovascular MRI has a sensitivity of 88% and specificity of 99% when detecting ventricular thrombus, making it the most accurate of all modalities.Reference Habash and Vallurupalli 21 , Reference Weinsaft, Kim and Shah 22 Transesophageal echocardiography is moderately invasive as a specialised piezoelectric transducer probe in the oesophagus emits ultrasound waves to visualise the most posterior structures of the heart; however, both transesophageal echocardiography and transthoracic echocardiography have the potential to miss the diagnosis because of limited resolution.Reference Attili, Schuster, Nagel, Reiber and van der Geest 23 , Reference Vaggar, Gadhinglajkar, Pillai, Sreedhar, Cahndran and Roy 24 Transthoracic echocardiography is a non-invasive method of obtaining two-dimensional or digitally generated three-dimensional images of the heart with a sensitivity of 40% for ventricular thrombus.Reference Weinsaft, Kim and Shah 22 , Reference Roifman, Connelly, Wright and Wijeysundera 25 Utilisation of three-dimensional echocardiography is thought to improve the diagnostic accuracy of detecting ventricular thrombus versus the two-dimensional approach; however, this is an area that necessitates further research. Further, the incorporation of ultrasound contrast with transthoracic echocardiography has been shown to improve its sensitivity from 24–33% to 23–61% and specificity from 94–95% to 96–99% compared with non-contrast transthoracic echocardiography.Reference Roifman, Connelly, Wright and Wijeysundera 25 , Reference Manning, Weintraub and Waksmonski 26 Although cardiovascular MRI is known to be better at detecting ventricular thrombus than is transthoracic echocardiography, cardiovascular MRI is unavailable at times and is expensive. Transthoracic echocardiography with contrast ultrasound may be a cost-effective alternative that is comparable to cardiovascular MRI in terms of sensitivity and specificity.Reference Habash and Vallurupalli 21 , Reference Weinsaft, Kim and Crowley 27 Coronary angiography involves the anatomic insertion of a catheter into the chambers and vessels of the heart while visualising structures via X-ray or CT, which can allow for distinction of different cardiomyopathies by the quantification of coronary artery stenosis and detect thrombi via detection of apical ballooning and filling defects.Reference Gulsin, Serna, Morris, Taher and Loke 28 Chest CT is another non-invasive diagnostic tool that combines a computer and X-ray technology to produce two-dimensional and digital three-dimensional images to assist in diagnosis.Reference Kassop, Donovan and Cheezum 29 Chest CT, however, has been reported to allow ventricular thrombus to often go undetected.Reference Lee, Kim and Hwang 30 , Reference Unai, Hirose, Entwistle and Samuels 31
Acknowledgements
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Financial Support This research received no specific grant from any funding agency, commercial or not-for-profit sectors.
Conflicts of Interest None.