ABC | Volume 114, Nº4, Suplement, April 2020

Anatomopathological Correlation Favarato & Benvenuti Heart failure after myocardial infarction an rupture of chordae tendineae Arq Bras Cardiol 2020; 114(4Suppl.1):47-56 current case, there were no coronary angiography alterations. Diagnoses of acute pulmonary edema and severe mitral regurgitation, probably acute, were made due to rupture of the chordae tendineae. 2 Thus, in the current case, despite the presence of critical lesions in the coronary arteries, the event described as acute myocardial infarction could have been only an increase in cardiac injury markers in the absence of infarction. Although mitral valve prolapse is generally associated with a low risk of cardiovascular complications, some publications have doubted this assumption. Avierinos et al., 3 in a population study in Olmsted County, Minnesota, found moderate or severe mitral regurgitation and left ventricular dysfunction as primary risk factors for cardiovascular mortality, with the first being greater than the latter. Mild mitral regurgitation, left atrial enlargement, a prolapsed cusp, atrial fibrillation and age older than 50 years were considered secondary risk factors. In this study, cardiovascular morbidity was 30%, overall mortality was 19% and cardiovascular mortality 9% in 10 years of follow-up. 3 In the Framingham study, 25% of patients with mitral valve prolapse developed significant mitral regurgitation or required surgery in a period of 3 to 16 years. 4 The rupture of the valvar chordae tendineae is the most common cause of acute mitral regurgitation and its most frequent causes are infective endocarditis, myxomatous degeneration and mitral valve prolapse; however, they can occur in rheumatic valve disease, chest trauma and atherosclerotic heart disease. 3,5,6 In the current case, tissue changes in the prolapse itself may be the cause of the rupture; however, one should always rule out infectious endocarditis in this type of complication. The diagnosis of infective endocarditis is based on clinical, laboratory and echocardiographic aspects. Duke’s criteria are the recommended ones. The diagnosis is made in the presence of 2 major criteria or 1 major and 3 minor, or even 5 minor criteria. The following are considered major criteria: positive blood culture for endocarditis (two cultures within a 12- hour interval or 3 cultures from two samples collected within a 1-hour interval between them for microorganisms commonly related to endocarditis - Streptococcus viridans , S. bovis , Staphylococcus aureus , or HACEK group, or Coxiella burnetiid culture. In addition to the blood culture, evidence of endocardial involvement on echocardiogram (preferably transesophageal) is considered as major criteria: oscillating intracardiac mass in the valve or its supporting structures; valve annular abscess, new or intensified regurgitation. Among the minor criteria are: predisposition – previous valvar heart disease, use of injectable drugs or venous catheters; elevation of inflammation markers; splenomegaly, hematuria; purpura; fever > 38ºC; vascular phenomena (arterial embolism, septic pulmonary infarction, mycotic aneurysm, intracranial or conjunctival hemorrhage and Janeway lesions); immunological phenomena (glomerulonephritis, Osler nodes, Roth’s spots and elevation of the Rheumatoid Factor); positive blood culture of microorganisms not usually associated with endocarditis. 7 In the current case, no vegetations were detected on the echocardiogram, there was no fever and a staphylococcus strain was identified in the blood culture that is not usually associated with endocarditis. Moreover, there was no evidence of endocarditis in the histopathological analysis of the valve fragments removed during surgery. Thus, the diagnosis of infectious endocarditis can be ruled out. This patient had rhabdomyolysis with the use of statins or due to severe ischemia, because in addition to the increase in creatine kinase (CK) levels, she also had an increase in liver enzymes suggestive of ischemic hepatitis. The rhabdomyolysis presentation was the classic one, with the presence of muscle pain, weakness, darkened urine and marked increase in creatine kinase (CK) levels. Also, its most common complication, acute renal failure, was present. Simvastatin and atorvastatin are metabolized by CYP3A4 (the most common cytochrome P450 isoenzyme), while rosuvastatin is metabolized by CYP2A9. Thus, the former are more susceptible to drug interactions that increase plasma concentrations and the probability of toxicity. Muscle symptoms are complaints that range from 1% to 10% of patients using statins; however, there is an increase in CK levels in less than 1%. 8 Ischemic hepatitis is characterized by cardiopulmonary or circulatory failure associated or not with arterial hypotension, massive and reversible elevation of liver aminotransferase enzymes (AST and ALT) and exclusion of other causes of severe liver damage, such as acetaminophen poisoning, viral hepatitis or another type of toxic hepatitis. In the current case, liver damage caused by statins cannot be ruled out and there was no increase in prothrombin times with iNR > 1.5 and the APTT time ratio was normal, alterations present in ischemic hepatitis. 9 The final stage of the disease of this patient was due to septicemia, which could be due to infection by toxin- producing Clostridium difficile . Only toxin-B producing C. difficile (TBcd) strains cause infection; however, some strains also produce toxin A (TAcd). They act by inactivating the Rho GTPases pathway through the glycosylation of the threonine residue, which leads to actin depolymerization and cell death and stimulates the inflammation cascade responsible for major tissue damage, diarrhea and pseudomembranous colitis. The use of antibiotics can lead to an imbalance of the intestinal microbiome with a decrease in Bacteroides and Firmicutes, allowing the proliferation of Clostridium difficile . Remember that the patient received broad spectrum antibiotics for a prolonged period. 10 (Dr. Desiderio Favarato) . Diagnostic hypothesis: mitral regurgitation due to ruptured chordae tendineae in mitral valve prolapse, septicemia and multiple organ failure. (Dr. Desiderio Favarato) . Necropsy On external examination of the corpse, partial dehiscence of the saphenectomy suture was noted, with little secretion from the surgical wound; the histological examination disclosed an extensive acute purulent inflammatory process in the dermis and hypodermis, with 52