Delayed surgical therapy in patients with prosthetic valve endocarditis - risk factor or not?

Objects: Despite advances in diagnostics, antibiotic regimens and surgical techniques, prosthetic valve endocarditis (PVE) remains a disease with a mortality of 20-40% and an incidence of 1% in the first year after surgery. Symptoms are unspecific and Duke criteria are more insensitive than in native valve endocarditis (NVE). The German Society of Cardiology recommends a conservative treatment of uncomplicated PVE and late PVE. However, patients treated with antibiotics due to PVE are transferred frequently to cardiac surgery due to an acute clinical deterioration. In this study investigation of the influence of delayed diagnosis and delayed surgical therapy on the outcome of patients who underwent cardiac surgery due to PVE was performed.

Methods: Between 09/2000 and 06/2010 surgery due to PVE was done in 149 patients. 109 (71,8%) were male and mean age was 63,5 ± 13,8 years. 65 patients (43,6%) presented with early PVE (≤1 year after valve replacement) and 84 (56,4%) with late PVE (≥1 year). Data was collected retrospectively from patient records and follow up was performed until 2011. Delayed diagnosis (symptom-diagnosis >30 d) and delayed surgery (diagnosis-surgery >30 d) were correlated with adverse events and significance was analyzed with SPSS® through COX analysis.

Results: 53 events (35,6%) were documented. 5 patients (3,4%) died intraoperatively, all transferred to cardiac surgery in a state of cardiogenic shock. 30 patients (20%) died from recurrence of PVE , 7 patients (4,7%) suffered from an early re-PVE and in 11 (7,4%) patients re-surgery had to be performed due to recurrence of PVE. Latency between symptoms and diagnosis >30 days was a risk factor (HR = 3,059; p < 0,05) for early events in multivariate COX Regression. Latency between diagnosis and surgery >30 days was no significant risk factor for early or late events in multivariate COX regression.

Conclusion: Prolonged latency between symptoms and diagnosis is a risk factors for early events in patients with surgery due to PVE, especially for recurrence of PVE. Since diagnosis of PVE is demanding, patients with prostheses of heart valves and symptoms of infection should be transferred to a heart center immediately.