Mitral endocarditis: 4.2% early mortality in minimally invasive approach

Minimally invasive surgery for mitral endocarditis: a new paradigm?

Infective endocarditis (IE) of the mitral valve remains a formidable pathology, with hospital mortality rates ranging between 17% and 33%. While median sternotomy (ST) remains the gold standard in current recommendations to ensure optimal exposure of infected tissues, the rise of minimally invasive techniques (MIS) — whether through mini-thoracotomies or robotic approaches — raises questions about their applicability in this context of high surgical complexity.

This meta-analysis, compliant with PRISMA criteria, aims to precisely evaluate the clinical outcomes of MIS in the treatment of mitral IE. By synthesising data from 14 retrospective studies including 949 patients, the authors seek to quantify long-term survival and the risk of infection-related reintervention. The study tests the hypothesis that the MIS approach could offer a safe alternative to sternotomy, allowing for accelerated postoperative recovery without compromising surgical safety or 10-year survival outcomes, even when faced with the anatomical challenges posed by vegetations and valvular abscesses.

Study design and data selection

This systematic review and meta-analysis was conducted according to PRISMA guidelines and registered in the PROSPERO database (ID: CRD420261370652). The authors performed an exhaustive search in the PubMed/MEDLINE, EMBASE, and Cochrane databases up to January 14, 2026, to identify studies focusing on the surgical treatment of mitral valve infective endocarditis (IE).

Population and samples

The analysis is based on 14 retrospective studies involving a total sample of 949 patients. Eligibility criteria included patients diagnosed with mitral IE who underwent minimally invasive surgery (MIS), including or not a comparison group treated by conventional median sternotomy (ST).

Experimental parameters and groups

The protocol evaluated two main axes:

• Single-arm analysis (MIS): evaluation of overall survival, IE-related reoperation rate, valve repair rate (performed in 52.5% of patients) and postoperative complications.
• Comparative analysis (MIS vs ST): comparison of long-term survival, length of stay in intensive care unit (ICU) and overall length of hospital stay.

The variables collected included demographic characteristics, comorbidities (diabetes, renal failure, stroke), intraoperative data (bypass time, aortic clamping), and microbiological data of the pathogens involved.

Statistical analysis methods

For the comparative meta-analysis, categorical variables were summarized by the odds ratio (OR) and continuous variables by the mean difference (MD). Survival data were reconstructed from the Kaplan-Meier curves published in the source studies. Heterogeneity between studies was quantified by the Q statistic and the I² index.

Meta-analysis results: Performance of the MIS approach

This systematic review and meta-analysis compiled data from 14 retrospective studies including a total of 949 patients operated on for mitral infective endocarditis (MIE). The results highlight the technical feasibility and safety of the minimally invasive surgery (MIS) approach compared to conventional sternotomy (ST).

Clinical outcomes and survival of the MIS cohort

In the MIS-treated group, early mortality (at 30 days) is reported at 4.2% (95% CI: 1.8% - 7.4%). Analysis of reconstructed survival data shows long-term sustainability of results, despite the inherent complexity of infectious pathologies:

• Overall survival: 86.7% at 1 year, 75.2% at 5 years and 56.2% at 10 years.
• Freedom from reoperation related to endocarditis: 97.5% at 1 year, 95.9% at 5 years and 90.7% at 10 years.
• Repair rate: Mitral valve repair was feasible in 52.5% of patients in the MIS cohort.

Comparative analysis: MIS vs Sternotomy (ST)

The secondary comparative meta-analysis identifies no statistically significant difference between the two approaches regarding long-term survival, but highlights a clear advantage in immediate postoperative recovery.

Les auteurs notent que si la survie est comparable, la réduction significative de la durée de séjour en unité de soins intensifs (USI) en faveur de la MIS constitue un bénéfice clinique majeur pour la gestion des ressources hospitalières et la cinétique de récupération du patient.

A robust surgical alternative to sternotomy

The results of this meta-analysis, involving 949 patients from 14 retrospective studies, provide major clinical insight: the minimally invasive surgery (MIS) approach is no longer a simple aesthetic option, but a credible therapeutic strategy for mitral valve infective endocarditis. With early mortality contained at 4.2% and long-term survival (56.2% at 10 years) comparable to conventional sternotomy (HR: 0.82), MIS demonstrates its ability to treat complex infectious pathologies without compromising valvular safety.

The most tangible benefit for the cardiac surgery department lies in the recovery kinetics. The study reports a significant reduction in intensive care stay of 1.52 days in favor of MIS. This acceleration of post-operative rehabilitation is crucial in these often fragile patients, without increasing the risk of reintervention related to infection (90.7% absence of reoperation at 10 years).

However, the interpretation must remain cautious. The authors point out that the data originate from retrospective studies, inducing a probable selection bias: cases presenting extensive abscesses or massive tissue destruction were preferentially directed towards a sternotomy. Nevertheless, for selected patients, the mitral repair rate of 52.5% shows that the exposure offered by mini-thoracotomy allows for a high-precision technical procedure.

Summary of results

This meta-analysis of 14 retrospective studies (949 patients) demonstrates that minimally invasive surgery (MIS) for mitral endocarditis is safe, with an early mortality rate of 4.2% and a 4-year survival rate equivalent to sternotomy (p=0.55). It allows for a significant reduction in intensive care stay by an average of 1.5 days, while maintaining a valve repair rate of 52.5% and high protection against infectious reinterventions (90.7% at 10 years).

In practical terms, for the practitioner:

• Optimize the care pathway: Integrate the minimally invasive approach to reduce the duration of intensive care unit bed occupancy without increasing the risk of mortality or long-term infectious recurrence.
• Preserve the valve: The study confirms that the minimally invasive technique allows for mitral repair in more than one in two cases (52.5%), thus preserving the functional benefits for the patient.
• Targeted selection: Although results are comparable to sternotomy, MIS remains an alternative for selected patients; sternotomy remains preferable in cases of extensive abscesses or complex multivalvular involvement requiring total exposure.

Study Lexicon

Minimally invasive mitral surgery (MIS): Surgical technique via lateral mini-thoracotomy (4-7 cm) or robotic assistance, offering an alternative to sternotomy to accelerate postoperative recovery.

Reoperation related to IE: Clinical parameter evaluating the durability of the initial intervention in the face of infectious recurrences or secondary valvular failures.

ICU stay: Key indicator of early morbidity, significantly reduced (p < 0.01) in patients treated with a minimally invasive approach in this meta-analysis.

Median sternotomy (ST): Historical surgical standard ensuring optimal exposure for the management of advanced endocarditis or unforeseen intraoperative findings.

Time-to-event data: Refined statistical analysis by reconstruction of Kaplan-Meier curves, allowing for the estimation of survival probabilities at 1, 5, and 10 years.

Mitral valve repair: Native valve preservation strategy, preferred here in 52.5% of cases, as opposed to prosthetic valve replacement.

Information intended for healthcare professionals. This content may contain errors or truncated summaries. We recommend always verifying with the original source article. Delynov disclaims all responsibility regarding the use of this information. This document is not intended for patients or the general public.