Introduction: The objective of this study was to analyze the incidence, clinical features, microbiology and prognosis of patients with infective endocarditis (IE) in Iceland, and to compare the results with a previous study made in Iceland 1976-85.

Material and Methods: A retrospective study including all patients diagnosed with IE in Iceland 2000–2009. Information was obtained from medical records.

Results: A total of 88 cases (71% men, mean age 59 years) were diagnosed and the incidence of IE was calculated 2.97/100.000 person-years. The mitral valve was infected in 35 patients (40%), aortic in 27 (31%) and tricuspid in 9 (10%). In 19 cases a prosthetic valve was infected (22%), one early (<60 days from procedure) and 18 late. Sixteen patients were intravenous drug users. The most common causative organisms were streptococcus (33%), staphylococcus (25%) and enterococcus (16%). Surgical intervention was performed in 16 cases (18%). One and five year survival was 77% and 57% respectively.

Conclusion: The incidence of IE in Iceland is still low compared to other countries. The clinical profile of the disease has changed since 1976-85, patients with prosthetic heart valves and intravenous drug users were more prominent than before. The microbiological spectrum has not changed much, streptococcus is still the most common pathogen, contrary to what is seen in other industrial countries where S. aureus is more frequent. Death rate is lower than before and one year survival good compared to other reports.

Figure I.  Age distribution of patients with infective endocarditis in Iceland 2000 – 2009. Mean age was 59 years and median age 65 years (1 – 91 years)

Figure II. Valve (or other intracardiac structures) involvement in patients diagnosed with infective endocarditis in Iceland 2000 – 2009. In 15 cases infection was in two valves or in a valve and a pacemaker wire, these cases are counted twice in the figure.

Figure III.  Kaplan Meier survival curve showing survival rate of 88 patients with infective endocarditis in 2000 – 2009 (red line) and a control group with the same age and gender distribution as the patient group (blue line). One and five year survival for patients wit IE  was 77% and 57% respectively. The patients had significantly lower survival rate than the control group (p < 0,01, log-rank test).

 

Table I. Microbiological etiology of infective endocarditis in 88 cases diagnosed in Iceland in 2000 – 2009 and in 71 cases diagnosed 1976 - 85 ².

Table II. Conditions predisposing infective endocarditis in 88 cases diagnosed in Iceland 2000 – 2009 and 71 patients diagnosed 1976 – 85 2.  Each patient can have more than one predisposing condition.

Table III:  Comparison between patient groups, prosthetic valve IE, iv. drug abusers and other patients diagnosed with IE in Iceland 2000 – 2009.