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One hundred cases of
peripartum Cardiomyopathy... and counting: what is going on? 1: Fett JD, Dowell DL, Carraway RD, Sundstrom JB, Ansari AA. Related Articles, Links One hundred cases of peripartum cardiomyopathy... and counting: what is going on? Int J Cardiol. 2004 Dec;97(3):571-3. No abstract available. PMID: 15561354 James D. Fett, MD 9-12-03 (1138 words) JD Fett, MD, Hôpital Albert Schweitzer, Deschapelles, Haiti DL Dowell, MD, Hôpital Albert Schweitzer, Deschapelles, Haiti RD Carraway, MD, Hôpital Albert Schweitzer, Deschapelles, Haiti JB Sundstrom, PhD, Emory University School of Medicine, Atlanta, GA, USA AA Ansari, PhD, Emory University School of Medicine, Atlanta, GA, USA 100 CASES OF PERIPARTUM CARDIOMYOPATHY. AND COUNTING: What's going on? We have previously documented a high-incidence area of peripartum cardiomyopathy (PPCM).1 Since initiating the PPCM Registry at Hospital Albert Schweitzer(HAS) on 1 Feb 2000, 108 new PPCM cases have been registered. This translates into an incidence of approximately 1 case per 300 live births in a district of 258,000 population, several times the estimated incidence in the United States.2 Murphy,3 in his chapter on PPCM in MYOCARDITIS: From Bench to Bedside, suggests this high incidence in Haiti may be attributed to multiple possible etiologies, such as human immunodeficiency virus, sickle cell disease, hookworm disease with severe anemia, and tuberculosis. However, all of those diseases and a long list of others have been to the best of our ability specifically ruled out, since PPCM is by definition a diagnosis of exclusion.4 As such, there must always be room for periodic reassessment if new clinical information becomes available. During the first year of the HAS PPCM Project over 50 % of new PPCM cases were first diagnosed in women following their 5th or higher pregnancy and fewer than 10 % in primiparas. While the grand multiparas continue to constitute over one-third of the new cases, in the third year of the project, one-third of new PPCM cases have been in primiparas, three of whom died shortly after admission to hospital in 2003, with severe congestive heart failure (CHF). In the HAS setting of high volume workload and limited resources cardiac catheterization and endomyocardial biopsy are not available. However, cardiac tissue exam from autopsy has demonstrated an inflammatory infiltrate in 1 of the 3 primiparas mentioned above. This infiltrate, on immunohistochemical staining, consisted of mononuclear cells, including T-lymphocytes (CD8) and monocyte/macrophage lineage cells (CD68). The second primipara's cardiac tissue at autopsy showed non-specific changes in the myocardium similar to those that may be seen in dilated cardiomyopathy of various etiologies, including PPCM. The third primipara's cardiac tissue at autopsy, in addition to the non-specific changes, showed areas of interstitial fibrosis (possible resolving or resolved myocarditis5). This is certainly compatible with the focal nature and stage of disease of myocarditis (and/or inflammatory cardiomyopathy) reported in PPCM.6 Lacking biopsy potential at HAS and because a focal myocarditis in PPCM may not even be found in limited autopsy tissue, we have attempted to identify peripheral blood markers of an inflammatory process. In the HAS setting the most promising test identified to-date is the high-sensitivity C-Reactive Protein (hs-CRP), demonstrated to be an indicator of activation of proinflammatory cytokines.7 In early testing (Unpublished, in preparation) 22 Haitian PPCM mothers have been found to have markedly increased mean hs-CRP plasma levels compared to 14 Haitian non-PPCM control mothers at the same stage postpartum (144.3 mg/L vs 5.2 mg/L, p=0.0003). Thirty-two Haitian PPCM mothers have also been found, as expected with stage III and IV NYHA Classification CHF, to have markedly elevated mean B-type Natriuretic Peptide (pro-BNP) plasma levels compared to 22 non-PPCM control Haitian mothers (1096.5 pg/ml vs 204.2 pg/ml, p=<0.00009). Once again, limited resources with lack of adequate cold storage have hampered our investigation since we would like to also measure proinflammatory cytokines Tumor Necrosis Factor-alpha (TNF-a), Interleukin-1 (IL-1) and Interleukin-6 (IL-6), all of which may prove useful targets for potential new immunomodulatory treatments.8,9,10 One might expect that nutritional deficiencies could play a role in the development of PPCM in this impoverished setting; however we have not demonstrated either a macro-nutrient deficiency (protein and iron) or a micro-nutrient deficiency (Vitamin A, Vitamin B-12, Vitamin C, Vitamin E, B-Carotene, Selenium) in Haitian PPCM patients or controls.11 Also in field epidemiology case-control studies we have not found any geographic distribution, cultural practices, customs, or activities which distinguish PPCM mothers from non-PPCM control mothers.12 It is certainly possible that unidentified nutritional deficiencies and/or environmental toxins/infectious agents could be playing a role in a process involving an aberrant immune response to as yet unidentified antigen(s). It is possible that PPCM has an autoimmune component, but this is not yet certain. Nonetheless, we have found plasma autoantibodies (AAB's) in more than half of 30 Haitian PPCM mothers tested to-date.11,13,14,15 The targets of such autoantibodies include human cardiac myosin heavy chain (200 Kd), putative cardiac transaldolase (37 Kd), putative cardiac myosin light chain (27 Kd), and yet-unidentified 25 and 33 Kd cardiac proteins. It is uncertain if these AAB's are merely secondary epiphenomena or if they could be directly contributing to cardiomyocyte injury. In the latter case they would be enticing targets for potential immunomodulatory treatments. There is evidence that these and/or other identified or unidentified AAB's may correlate with severity of cardiac dysfunction16 and that removal may be associated with clinical improvement in dilated cardiomyopathy.17 Some non-PPCM Haitian control mothers have also been found to have plasma AAB's, elevated hs-CRP, abnormal or borderline echocardiograms (in one returning later to normal), but normal BNP (i.e. not in left ventricular failure). Does this mean that they have developing or latent, sub-clinical PPCM? We do not know, but this is a subject of current study. It is highly important for us to define a non-invasive methodology that can predict the onset of human PPCM so that preventive measures can be instituted. This is one of the goals of our research efforts. In treatment we have learned that an ACE-inhibitor is our most valuable medication, not only because of its direct beneficial effects on the heart but also because of its potential benefit to interrupt the chain of events in the pathobiology of PPCM.18 More effective treatments are urgently needed This meticulous identification and characterization of PPCM diagnosis-of-exclusion patients in one high-incidence area through a PPCM Registry continues to be the focus of multiple ongoing studies. Whether this growing body of evidence will shed light on PPCM in the USA and other resource-abundant countries remains to be seen. Although incomplete, at the very least our study suggests that it may be prudent to investigate plasma/serum levels of hs-CRP, TNF-a, IL-1, IL-6, and cardiac-specific autoantibodies in PPCM patients wherever in the world these patients appear. It also suggests that endomyocardial biopsy in settings where it can be accomplished may have an increasingly important role in those PPCM mothers who are not improving in the early phase of disease.20 This is particularly the case with newer immunomodulatory treatments on the horizon. REFERENCES: 1. Fett JD, Carraway RD, Dowell DL, King ME, Pierre R. Peripartum cardiomyopathy in the Hospital Albert Schweitzer District of Haiti. Am J Obstet Gynecol 2002;186:1005-10. 2. Pearson GD, Veille JC, Rahimtoola S, Hsia J, Oakley CM, Hosenpud JD, Ansari AA, Baughman KL. Peripartum cardiomyopathy. National Heart, Lung and Blood Institute and Office of Rare Diseases (National Institutes of Health) Workshop recommendations and review. JAMA 2000;283:1183-8. 3. Murphy JG. Chapter 24:Peripartum Cardioimyopathy. MYOCARDITIS: From Bench to Bedside. Cooper LT, Ed. Humana Press, Totowa, New Jersey, 2003. 4. Demakis JG, Rahimtoola SH. Peripartum cardiomyopathy. Circulation 1971;44:964-8. 5. 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Curr Pharm Des 2003;9:723-35. 11. Fett JD, Ansari AA, Sundstrom JB, Combs GR Jr. Peripartum cardiomyopathy: a selenium disconnection and an autoimmune connection. Int J Cardiol 2002;86:311-16. 12. Fett JD, Carraway RD, Perry H, Dowell DL. Emerging insights into peripartum cardiomyopathy. J Health Popul Nutr 2003;21:1-7. 13. Sundstrom JB, Fett JD, Carraway RD, Ansari AA. Is peripartum cardiomyopathy an organ specific autoimmune disease? Autoimmunity Rev 2002;1:73-7. 14. Ansari AA, Fett JD, Carraway RD, Mayne AE, Onlamoon M, Sundstrom JB. Autoimmune mechanisms as the basis for human peripartum cardiomyopathy. Clin Rev Allergy Immunol 2002;23:301-24. 15. Warraich RS, Sliwa K, Ansari AA, Sundstrom BJ, Yacoub MH, Fett JD. Autoantibody profiles in patients with peripartum cardiomyopathy: a distinct entity to idiopathic dilated cardiomyopathy. Eur Heart J 2003;24: Suppl Aug-Sep, 189. 16. Warraich RS, Noutsias M, Kasac I, Seeberg B, Dunn MJ, Schultheiss HP, Yacoub MH, Kuhn U. Immunoglobulin G3 cardiac myosin autoantibodies correlate with left ventricular dysfunction in patients with dilated cardiomyopathy: immunoglobulin G3 and clinical correlates. Am Heart J 2002;143:1076-84. 17. Felix SD, Straudt A, Friedrich GB. Improvement of cardiac function after immunoadsorption in patients with dilated cardiomyopathy. Autoimmunity 2001;34:211-5. 18. Godsel LM, Leon JS, Wang K, Fornek JL, Molteni A, Engman DM. Captopril prevents experimental autoimmune myocarditis. J Immunol. 2003;171:346-52. 19. Sliwa K, Skudicky D, Candy G, Bergemann A, Hopley M, Sareli P. The addition of pentoxifylline to conventional therapy improves outcome in patients with peripartum cardiomyopathy. Eur J Heart Fail. 2002;4:305-9. 20. Klingel K, Sauter M, Bock CT, Szalay G, Schnorr JJ, Kandolf R. Molecular pathology of inflammatory cardiomyopathy. Med Microbiol Immunol (Berl). 2003 Aug 14 [Epub ahead of print]. |