Mitral valve infective endocarditis: putting the puzzle pieces together^†

We read with great interest the study by Perrotta et al. [1] who explored the results of 128 patients undergoing 140 procedures for mitral valve infective endocarditis (IE). The authors demonstrated high mitral valve repair rates with low early mortality and are to be congratulated on their results.

IE remains a challenging disease in terms of diagnosis, prevention of IE-related complications and timing of surgery. Radical resection of all infected tissue—as recommended by the current European Society of Cardiology/European Association for Cardio-Thoracic Surgery (ESC/EACTS) guidelines on the management of IE [2]—is the cornerstone of surgical treatment. In our experience, radical resection will eliminate the risk of IE relapses, even in cases when extensive tissue destruction is present, and a large amount of prosthetic material is needed to replace or repair multiple valves and cardiac structures [3]. As the authors acknowledge, incomplete resection of the infected tissue may be responsible for the high IE relapse rate observed in their study. This is an important observation and underlines that radical resection of all infected tissue should be performed independent of its effect on the probability of valve repair. Interestingly, the authors also observed that beyond the early postoperative period, the Kaplan–Meier survival curves were parallel for patients who underwent either valve repair or replacement. Although not clear from this study, a worse patient profile can explain the differences in early mortality, questioning the clinical benefit of valve repair in the long term. Taking into account that the hazard of dying was not constant, a landmark analysis would be needed to explore such speculations. Nevertheless, their results do support the radical resection approach, irrespective of repair possibilities. Their results are quite similar to the recent report by Toyoda et al. [4] who explored the results of valve repair versus replacement in 1970 patients undergoing mitral valve surgery for IE. Again, the difference in survival (favouring valve repair) was driven predominantly by differences in early mortality. Valve repair in patients with IE is technically challenging, often necessitating complex patch techniques to restore valve competency [5]; this will increase the risk of technical failure and incorporate additional risk of repair failure related to structural degeneration of the implanted patch. In our opinion, valve repair in these patients will provide a clinical benefit only in cases when (i) radical resection of all infected tissue is carefully performed and (ii) a durable valve repair can be secured. In our experience, this is possible in approximately 60% of patients with active native mitral valve IE [6]. Further studies are needed to establish the survival benefit of valve repair in this setting.

In conclusion, the study by Perrotta et al. [1] clearly highlights the difficulties related to surgical management of mitral valve IE. Radical resection of all infected tissue and a structured approach to valve repair are crucial to prevent relapses and to secure good repair durability.

Conflict of interest: none declared.

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Author notes