My patient with brain tumor suffered a myocardial infarction (MI) just before having a diagnostic brain surgery. Could the tumor have placed him at higher risk of a coronary event?

Yes! Arterial thromboembolism—just as venous thromboembolism— is more common in patients with cancer.

In a large 2017 epidemiologic study involving patients 66 years of age or older, the 6-month cumulative incidence of MI was nearly 3-fold higher in newly-diagnosed cancer patients compared to controls, with the excess risk resolving by 1 year. 1 These findings were similar to a previous report involving patients with newly-diagnosed cancer, although in that study the overall coronary heart disease risk remained slightly elevated even after 10 years. 2

In addition, the incidence of coronary events and unstable ischemic heart disease during the 2 year period prior to the diagnosis of cancer is 2-fold higher among cancer patients suggesting that ischemic heart disease may be precipitated by occult cancer. 3

The association of cancer and thromboembolic coronary events may be explained through several mechanisms, including development of a prothrombotic or hypercoagulable state through acute phase reactants, abnormal fibrinolytic activity and increased activation of platelets which are also significantly involved in the pathophysiology of acute coronary syndrome (ACS). 4 Coronary artery embolism from cancer-related marantic endocarditis may also occur.5

More specific to our case, primary brain tumors may be associated with a hypercoagulable state through expression of potent procoagulants such as tissue factor and tissue factor containing microparticles, with a subset producing carbon monoxide, another procoagulant. 6

So our patient’s MI prior to his surgery for brain tumor diagnosis might have been more than a pure coincidence!

Bonus Pearl: Did you know that cancer-related prothrombotic state, also known as  “Trousseau’s syndrome” was first described in 1865 by Armand Trousseau, a French physician who diagnosed the same in himself and died of gastric cancer with thrombotic complications just 2 years later? 7,8

References

  1. Navi BB, Reinder AS, Kamel H, et al. Risk of arterial thromboembolism in patients with cancer. JACC 2017;70:926-38. https://www.ncbi.nlm.nih.gov/pubmed/28818202
  2. Zoller B, Ji Jianguang, Sundquist J, et al. Risk of coronary heart disease in patients with cancer: A nationwide follow-up study from Sweden. Eur J Cancer 2012;48:121-128. https://www.ncbi.nlm.nih.gov/pubmed/22023886
  3. Naschitz JE, Yeshurun D, Abrahamson J, et al. Ischemic heart disease precipitated by occult cancer. Cancer 1992;69:2712-20. https://www.ncbi.nlm.nih.gov/pubmed/1571902
  4. Lee EC, Cameron SJ. Cancer and thrombotic risk: the platelet paradigm. Frontiers in Cardiovascular Medicine 2017;4:1-6. https://www.ncbi.nlm.nih.gov/pubmed/29164134
  5. Lee V, Gilbert JD, Byard RW. Marantic endocarditis-A not so benign entity. Journal of Forensic and Legal Medicine 2012;19:312-15. https://www.ncbi.nlm.nih.gov/pubmed/22847046
  6. Nielsen VG, Lemole GM, Matika RW, et al. Brain tumors enhance plasmatic coagulation: the role of hemeoxygenase-1. Anesth Analg 2014;118919-24. https://www.ncbi.nlm.nih.gov/pubmed/24413553
  7. Thalin C, Blomgren B, Mobarrez F, et al. Trousseau’s syndrome, a previously unrecognized condition in acute ischemic stroke associated with myocardial injury. Journal of Investigative Medicine High Impact Case Reports.2014. DOI:10.1177/2324709614539283. https://www.ncbi.nlm.nih.gov/pubmed/26425612
  8. Samuels MA, King MA, Balis U. CPC, Case 31-2002. N Engl J Med 2002;347:1187-94. https://www.nejm.org/doi/pdf/10.1056/NEJMcpc020117?articleTools=true

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My patient with brain tumor suffered a myocardial infarction (MI) just before having a diagnostic brain surgery. Could the tumor have placed him at higher risk of a coronary event?

Why is my hospitalized patient with alcohol withdrawal syndrome so thrombocytopenic?

Although thrombocytopenia associated with chronic alcoholism may be related to complications of cirrhosis (eg, platelet sequestration in spleen due to portal hypertension, poor platelet production, and increased platelet destruction) (1), it may also occur in the absence of cirrhosis due to the direct toxic effect of alcohol on platelet production and survival (2).

 
In a prospective study of patients ingesting the equivalent of a fifth or more daily of 86 proof whiskey admitted for treatment of alcohol withdrawal—without evidence of severe liver disease, infection or sepsis— 81% had initial platelet counts below 150,000/µl, with about one-third having platelet counts below 100,000 µl (as low as 24,000/ul) (3).
In most patients, 2-3 days elapsed before the platelet count began to rise significantly, peaking 5-18 days after admission. Others have also reported that platelet counts rise within 5-7 days and normalize in a few weeks after alcohol withdrawal (1); bleeding complications have been uncommon in this setting.
Perhaps even more intriguing is the report of the association between thrombocytopenia in early alcohol withdrawal and the development of delirium tremens or seizures (sensitivity and specificity ~ 70%, positive predictive value less than 10% but with a negative predictive value of 99%) (4)! In fact, the authors suggested that, if their findings are corroborated, a normal platelet count could potentially be used to identify patients at low risk of alcohol withdrawal syndrome and therefore outpatient therapy. 

References
1. Mitchell O, Feldman D, Diakow M, et al. The pathophysiology of thrombocytopenia in chronic liver disease. Hepatic Medicine: Evidence and Research 2016;8 39-50. https://www.dovepress.com/the-pathophysiology-of-thrombocytopenia-in-chronic-liver-disease-peer-reviewed-article-HMER

2. Cowan DH. Effect of alcoholism on hemostasis. Semin Hematol 1980;17:137-47. https://www.ncbi.nlm.nih.gov/pubmed/6990498

3. Cowan DH, Hines JD. Thrombocytopenia of severe alcoholism. Ann Intern Med 1971;74:37-43. http://annals.org/aim/article-abstract/685069/thrombocytopenia-severe-alcoholism.

4. Berggren U, Falke C, Berglund KJ, et al. Thrombocytopenia in early alcohol withdrawal is associated with development of delirium tremens or seizures. Alcohol & Alcoholism 2009;44:382-86. https://www.ncbi.nlm.nih.gov/pubmed/19293148

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Why is my hospitalized patient with alcohol withdrawal syndrome so thrombocytopenic?

My patient with COPD has new clubbing of his finger tips. What is the mechanism of clubbing?

The mechanism behind digital clubbing has yet to be fully elucidated, with hypotheses ranging from a circulating vasodilator, tissue hypoxia, a neurocirculatory reflex, and genetic factors. 1 Although hypoxemia is often cited as a cause of clubbing, it is often absent in the presence of clubbing and many patients with hypoxemia do not have clubbing.

A potentially unifying pathophysiologic mechanism of clubbing revolves around platelet clustering and associated growth factor release. 2.3 Platelet clumps/megakaryocytes—either because of circumvention of the lung capillary network (eg, in intracardiac shunts or lung cancer) or increased production (eg, in left-sided endocarditis or chronic inflammatory conditions)—may wedge in the fine vasculature of distal fingertips or toes and cause release of platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF).

Together, PDGF and VEGF promote neovascularization, increase vessel dilation and permeability, and modify connective tissue to create the distinct club-like appearance. Local hypoxic condition from reduced capillary perfusion is thought to further stimulate the release of these growth factors.

Potential causes of clubbing in our patient include lung cancer, interstitial lung disease, bronchiectasis, core pulmonale and secondary polycythemia, among many others. 1

Fun Fact: Did you know that clubbing, also known as “Hippocratic finger”, was first described by Hippocrates in a patient with chronic empyema (don’t ask how chronic empyema was diagnosed in 400 BC!)?1

 

References

  1. McPhee SJ. Clubbing. In: Walker HK, Hall WD, Hurst JW, editors. Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition. Boston: Butterworths;1990. Chapter 44. Available from https://www.ncbi.nlm.nih.gov/books/NBK366/
  2. Dickinson CJ, Martin JF. Megakaryocytes and platelet clumps as the cause of finger clubbing. Lancet 1987;2:1434-4. https://www.ncbi.nlm.nih.gov/pubmed/2891996/ 
  3. Atkinson S, Fox SB. Vascular endothelial growth factor (VEGF)-A and platelet-derived growth factor (PDGF) play a central role in the pathogenesis of digital clubbing. J Pathol 2004;203:721-8. https://www.ncbi.nlm.nih.gov/pubmed/15141388

 

Contributed by George Bugarinovic, Medical Student, Harvard Medical School

My patient with COPD has new clubbing of his finger tips. What is the mechanism of clubbing?

Why has my hospitalized patient with head and neck cancer developed thrombocytosis few days following surgery?

An acute rise in platelet count is not uncommon among hospitalized patients and may be related to several factors, including “tissue damage” from a surgical procedure, infection, and acute blood loss1.  Postoperative thrombocytosis is thought to be related to increased platelet production as well as redistribution of platelets from the splenic platelet pool to the general circulation1.  Increased levels of megakaryocytic growth factors such as thrombopoietin, and pro-or anti-inflammatory cytokines such as interleukin (IL)-1, 3, 6, or 11 may also stimulate megakaryopoeisis in the setting of inflammation2.

Less well known is that enoxaparin (Lovenox), an anticoagulant commonly used for prevention of thromboembolic events in hospitalized patients, may also cause reactive thrombocytosis, usually within the first 2 weeks of therapy and resolving 2 weeks following its discontinuation3

Although malignancy is also associated with secondary thrombocytosis, given its acute nature in our patient, it is less likely to be playing a role.

 

References

  1. . Griesshammer M, Bangerter M, Sauer T, et al. Aetiology and clinical significance of thrombocytosis: analysis of 732 patients with an elevated platelet count. J Intern Med 1999;245:295-300. https://www.ncbi.nlm.nih.gov/pubmed/10205592
  2. Kulnigg-Dabsch S, Schmid W, Howaldt S, et al. Iron deficiency generates secondary thrombocytosis and platelet activation in IBD: the randomized, controlled thromboVIT trial. Inflamm Bowel Dis 2013;published online, DOI10.1097/MIB.0b013e318281f4db. https://www.ncbi.nlm.nih.gov/pubmed/23644823
  3. Hummel MC, Morse BC, Hayes LE. Reactive thrombocytosis associated with enoxaparin. Pharmacotherapy 2006;26:1667-1670. https://www.ncbi.nlm.nih.gov/pubmed/17064215

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Why has my hospitalized patient with head and neck cancer developed thrombocytosis few days following surgery?

Does electroconvulsive therapy (ECT) pose a risk of embolic stroke in patients with atrial fibrillation (AF)?

Acute embolic stroke in the setting of AF without anticoagulation after ECT has been reported in a single case report in the absence of conversion to normal sinus rhythm (1). Several cases of episodic or persistent conversion to normal sinus rhythm (NSR) in patients with AF undergoing ECT have also been reported (in the absence of embolic stroke), leading some to recommend anticoagulation therapy in such patients (2), though no firm data exist.

The mechanism by which ECT promotes cardioversion from AF to NSR is unclear as direct electrical influence of ECT on the heart is thought to be negligible (1). Arrhythmias such as atrial flutter and AF have also been reported after ECT (1). Curiously, ECT is associated with increased 5- hydroxytryptamine (5- HT2)-receptor densities of platelets in patients with depression which may enhance platelet reactivity and increase the risk of embolic stroke (3) even in the absence of cardioversion.

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References

  1. Suzuki H, Takano T, Tominaga M, et al. Acute embolic stroke in a patient with atrial fibrillation after electroconvulsive therapy. J Cardiol Cases 2010; e12-e14. https://www.sciencedirect.com/science/article/pii/S1878540910000113
  2. Petrides G, Fink M. Atrial fibrillation, anticoagulation, electroconvulsive therapy. Convulsive Therapy 1996;12:91-98. https://journals.lww.com/ectjournal/Abstract/1996/06000/Atrial_Fibrillation,_Anticoagulation,_and.4.aspx
  3. Stain-Malmgren R, Tham A, Ǻberg-Wistedt A. Increased platelet 5-HT2 receptor binding after electroconvulsive therapy in depression. J ECT 1998;14:15-24. https://europepmc.org/abstract/med/9661089
Does electroconvulsive therapy (ECT) pose a risk of embolic stroke in patients with atrial fibrillation (AF)?