A rare case of infective myocardial infarction

Abstract Background Prosthetic valve endocarditis (PVE) occurs in 1–6% of patients with valve prostheses. The most common agent of late PVE are S. aureus and Streptococci. Spondylodiscitis may precede the onset of endocarditis or may be the first clinical manifestation. Coronary embolization is a rare but possible complication of endocarditis. Case report: A 61 years–old man was admitted to the Emergency Department for low back pain, fever and chest pain. Four years before he underwent mitral valve bioprosthesis implantation and hybrid myocardial revascularization (percutaneous on right coronary artery). During observation cardiac arrest from ventricular fibrillation occurred, treated with single shock and evidence of anterolateral myocardial infarction at ECG. An urgent coronarography revealed chronic occlusion of CABG on LAD and acute occlusion, of possible embolic origin, involving LAD mid tract, first diagonal branch and intermediate branch. Thromboaspiration and subsequent PTCA was performed. For hemodynamic instability inotropic and vasopressor supports were started. A transthoracic echocardiogram showed severe left ventricular dysfunction (EF 25%) and 3.5x1mm endocardial vegetation on the mitral bioprosthesis without significant bioprosthesis dysfunction (confirmed by transesophageal echocardiogram). Blood cultures resulted positive for Streptococcus gordonii and antibiotic therapy based on the antibiogram was begun. Cardiac surgery was ruled out due to prohibitive surgical risk despite high probability of embolization. Because of the history of back pain spinal MRI was performed with evidence of cervial and lumbosacral spondylodiscitis. Neurosurgical indications were ruled out. Levosimendan infusion allowed weaning of vasopressor and inotropic therapy, however without improvement of left ventricular ejection fraction. Daily echocardiographic follow–up showed disappearance of the vegetation. Antibiotic targeted therapy was continued for 5 months, given the persistence of spondylodiscitis, in anticipation of intracardiac defibrillator (ICD) implantation in primary prevention. Conclusion PVE is a severe clinical condition associated with high morbidity and mortality. Antibiotic therapy is recommended for at least 6 weeks in PVE, in this case prolonged up to 5 months given the need to implant an ICD. Regarding the treatment of embolic infarction thromboaspiration is recommended as the initial strategy and, if successful, may be the only interventional option.