Impact of preoperative body mass index on postoperative outcomes in infective endocarditis: a multicenter analysis of 4801 consecutive patients.

Background: The impact of body weight disorders on outcomes of patients undergoing cardiac surgery for infective endocarditis (IE) have been poorly studied. Obesity or malnutrition may significantly influence the course and prognosis of endocarditis, driven by distinct comorbidities and microbiological profiles. Hence, we investigated the impact of preoperative body mass index (BMI) on postoperative outcomes in a large multicentric cohort of surgically treated IE patients.

Methods: Data from the Clinical Multicenter Project for Analysis of Infective Endocarditis in Germany (CAMPAIGN) registry (n = 4917) was used for retrospective analysis. The patients were divided into four groups for comparison according to their BMI: (1) underweight (≤18.5 kg/m²), (2) normal-weight (18.6-24.9 kg/m²), (3) overweight (25.0-29.9 kg/m²), (4) obesity (≥30.0 kg/m²). Patients with incomplete data on body weight or height were excluded (n = 116). The primary outcomes were 30-day and 1-year mortality.

Results: The final study cohort comprised 4801 patients, including 133 underweight patients (2.8%), 1884 normal-weight patients (39.2%), 1797 patients with overweight (37.4%), and 987 patients with obesity (20.6%). The mean age in the entire cohort was 65.0 [54.0-73.0] years. Patients with obesity had more comorbidities, including hypertension (63.0%; p < 0.001), diabetes mellitus (45.7%, p < 0.001), coronary artery disease (29.5%; p < 0.001), previous cardiac surgery (32.2%, p < 0.012) and dialysis-dependent chronic kidney disease (11.6%, p < 0.001). Patients with obesity had the highest prevalence of staphylococcal endocarditis (33.4%; p < 0.001), while underweight patients had more streptococcal infection (22.0%; p < 0.001). Patients with obesity had the worst 30-day and 1-year mortality rates after surgery for IE (14.1% and 19.6%, p < 0.001 and p < 0.001 respectively).

Conclusions: IE patients with obesity present with comorbidities, higher 30-day mortality and lower 1-year survival rates, possibly linked to more frequent staphylococcal infections and comorbidities. This emphasises the need for early risk stratification, enhanced infection prevention and improved perioperative care in patients with obesity.