Periannular extension of infective endocarditis.

Objectives: This prospective study was designed to assess the current clinical course, risk factors, microbiologic profile and echocardiographic findings of patients with left-sided endocarditis and perivalvular complications.

Background: Periannular complications worsen the prognosis of patients with endocarditis. The relation between these complications and the clinical and microbiologic data has not been clearly defined.

Methods: In this clinical cohort study, 211 patients with left-sided endocarditis, according to the Duke criteria, were prospectively recruited. All patients underwent conventional and transesophageal echocardiography. The mean follow-up interval was 151 days.

Results: Perivalvular complications were detected in 78 patients (37%). The incidence of periannular extension of infection in native and prosthetic valves was 29% and 55%, respectively. The presence of prosthesis (relative risk [RR] 1.88, 95% confidence interval [CI] 1.35 to 2.64) and previous endocarditis (RR 1.78, 95% CI 1.16 to 2.7) were the only pre-existing heart conditions associated with perivalvular complications. Aortic infection (RR 1.8, 95% CI 1.23 to 2.66) and the development of atrioventricular (AV) block (RR 2.55, 95% CI 1.91 to 3.41) were related with the existence of these complications. Coagulase-negative staphylococci were very common in patients with perivalvular complications (RR 1.77, 95% CI 1.21 to 2.59), and small vegetations were more frequent in these patients (RR l.45, 95% CI 0.95 to 2.22). An operation was more frequently performed in patients with perivalvular complications, but mortality was similar in patients with and without these complications.

Conclusions: Aortic infection, prosthetic endocarditis, new AV block and coagulase-negative staphylococci were independent risk factors of periannular complications. The period between symptom onset and diagnosis, the incidence of pericardial effusion and persistent signs of infection were similar between patients with and without perivalvular complications. Patients with perivalvular complications did not demonstrate a difference in the presence or size of vegetations or the frequency of embolism. An operation was more frequently performed in these patients, but mortality was similar in both groups.