Heart failure is uncommon in mast cell patients, but is noteworthy as a condition that involves mast cell activation. One study of adults with SM found 12 patients out of 548 had congestive heart failure. A small study with 18 MCAS patients found that persistent mast cell activation did not affect such parameters as systolic left ventricular function, systolic and diastolic left ventricular diameter, or shortening fraction. These markers are often tied to heart failure. In that same study, 12/18 MCAS patients did exhibit a diastolic left ventricular dysfunction. This defect is a sensitive indicator of changes to the myocardium, muscle around the heart and can be found using Doppler imaging. Five of those MCAS patients also showed hypertrophy in the left ventricle, a thickening of tissue that can be linked to heart damage.
Importantly, these findings were not linked to chronic heart failure in this population. Mast cell patients should be aware that while these anatomical changes of the left ventricle may be present, there is not currently any indication that their increase the frequency of symptomatic heart failure in this population. Mast cells are heavily involved in tissue remodeling and it is possible that local mast cell activation can lead to laying of additional tissue or scarring. Tryptase, chymase and matrix metalloproteinases, all released by mast cells, participate in tissue remodeling and fibrosis.
Tryptase has been associated with both heart failure and atherosclerosis, involved in coronary disease and syndromes. A number of other mediators can also contribute to heart failure, including histamine, platelet activating factor, IL-4, IL-6, IL-10, TNF, fibroblast growth factor (FGF) and transforming growth factor beta (TGFB).
Treatment of heart failure in mast cell patients is not terribly different from that of the general population. Diuretics are often used first, including furosemide. Angiotensin receptor antagonists like losartan are good choices for mast cell patients since ACE inhibitors and beta blockers should be avoided wherever possible. Calcium channel blockers like verapamil can be used. Spironolactone or similar medications may provide additional benefit. Ivabradine, a newer medication that works by affecting the funny current (Author’s note: Not a joke! My favorite pathway name), is also a consideration. Digoxin is appropriate for atrial fibrillation (afib) where other attempts to correct rhythm have failed.
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Gonzalez-de-Olano D, et al. Mast cell-related disorders presenting with Kounis Syndrome. International Journal of Cardiology 2012: 161(1): 56-58.
Kennedy S, et al. Mast cells and vascular diseases. Pharmacology & Therapeutics 2013; 138: 53-65.