Mitral Annular Calcification With <i>Staphylococcus aureus</i> Periannular Abscess
Bibliographic record
Abstract
A 99-year-old woman presented to the hospital with generalized back pain. The patient's medical history included systemic arterial hypertension and mild chronic renal failure. There was no history of fever or delirium. The patient was afebrile and normotensive with no respiratory distress, and findings on cardiopulmonary examination were unremarkable. Palpation of the abdomen revealed right upper quadrant tenderness without guarding. A complete blood cell count revealed leukocytosis with neutrophilia and a left shift. The patient had evidence of chronic renal failure with a mildly elevated urea. Her serum lactate level was mildly elevated, and she was admitted with a diagnosis of possible bowel ischemia. She was observed for signs of a surgical abdomen and did not receive prophylactic antibiotic therapy. Blood cultures were not performed. Three days after admission, the patient was found unresponsive, and she died shortly thereafter.A complete postmortem examination revealed no bowel ischemia. The heart weighed 400 g, secondary to mild, concentric left ventricular hypertrophy. Changes of mild congestive heart failure were present. Cultures of a 200-mL purulent pericardial effusion grew abundant Staphylococcus aureus.Examination of the cardiac valves revealed severe mitral annular calcification (MAC), indicated by small dark arrows, at the junction of the left ventricle (V) and left atrium (A). The overlying thrombus had eroded and perforated the posterior mitral valve leaflet (white arrows).Microscopy of the MAC revealed amorphous basophilic calcific debris intimately associated with clusters of gram-positive cocci, consistent with Staphylococcus infection. Myocardial and adrenal septic emboli were discovered, along with myocardial, renal, cerebral, and cerebellar microabscesses. Early purulent leptomeningitis was also present. Our patient's cause of death was sepsis, secondary to a S aureus periannular abscess superimposed on MAC.With an aging population, MAC is not an uncommon finding at antemortem imaging or at postmortem examination. MAC is commonly associated with disorders of calcium-phosphate metabolism, including chronic renal failure. MAC is usually solid in consistency; however, liquefactive necrosis can occur; these semisolid masses may penetrate the myocardium and protrude into the left atrial cavity forming a mass.Mitral valves with annular calcification are predisposed to developing both infective endocarditis and periannular abscesses. Although MAC is common, documented sepsis secondary to valvular or perivalvular infection is uncommon and is likely underreported because of difficulties in antemortem diagnosis. With the aging population, MAC may be a more commonly encountered site of infection.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".