Determinants and consequences of positive valve culture when cardiac surgery is performed during the acute phase of infective endocarditis

The optimal timing of cardiac surgery in infective endocarditis (IE) remains debated: Early surgery decreases the risk of embolism, and heart failure, but is associated with an increased rate of positive valve culture. To determine the determinants, and the consequences, of positive valve culture when cardiac surgery is performed during the acute phase of IE, we performed a retrospective study of adult patients who underwent cardiac surgery for definite left-sided IE (Duke Criteria), in two referral centres. During the study period (2002–2016), 148 patients fulfilled inclusion criteria. Median age was 65 years [interquartile range, 53–73], male-to-female ratio was 2.9 (110/38). Cardiac surgery was performed after 14 days [5–26] of appropriate antibiotics. Valve cultures returned positive in 46 cases (31.1%). Factors independently associated with positive valve culture were vegetation size ≥ 10 mm (OR 2.83 [1.16–6.89], P = 0.022) and < 14 days of appropriate antibacterial treatment before surgery (OR 4.68 [2.04–10.7], P < 0.001). Positive valve culture was associated with increased risk of postoperative acute respiratory distress syndrome (37.0% vs. 15.7%, P = 0.008) but was associated neither with an increased risk of postoperative relapse nor with the need for additional cardiac surgery. Duration of appropriate antibacterial treatment and vegetation size are independently predictive of positive valve culture in patients operated during the acute phase of IE. Positive valve culture is associated with increased risk of postoperative acute respiratory distress syndrome.