Mitral valve abscess: echocardiographic imaging, microbiology, management, and outcomes

Data regarding mitral valve (MV) abscess, a severe complication of infective endocarditis, are limited. This study aimed to describe the clinical, microbiological, echocardiographic, and surgical characteristics of MV abscess.

We conducted a retrospective study of adults (≥18 years) with MV abscess identified from the echocardiographic (October 2010-August 2020) and cardiothoracic surgical databases (April 2002-January 2020) at our centre. Data were obtained from electronic medical records. The primary endpoint was all-cause mortality. A total of 154 patients were included [median age 59 years, interquartile range (IQR): 47-68 years; 45% female], with a follow-up of 296 days (IQR: 6-1825 days). Native valves were affected in 69% of cases. Coagulase-negative Staphylococci (22%) were the most common pathogens, followed by Streptococci (20%), methicillin-resistant staphylococcus (16%), and methicillin-sensitive staphylococcus (14%). Surgery was performed in 146 patients, while 8 were managed conservatively. Bioprosthetic MV replacement was the common surgery (77%), and 27% required a Commando procedure. At surgery, MV abscess (64%) and abscess cavity (32%) were the predominant findings. Surgical classification specified the location and extension of the abscess, with posteromedial annulus being most commonly involved (64%). Mortality was 10% at 30 days, 33% at 1 year, and 71% during the entire follow-up period, without significant differences between native and prosthetic valve groups (P = 0.116).

MV abscess is a highly morbid condition. Detailed surgical classification supports operative planning and assessment of disease extent. Despite high rates of complex surgery, mortality remains substantial, underscoring the aggressive nature of this condition.