Comparison of clinical features of left-sided infective endocarditis involving previously normal versus previously abnormal valves.

Native valve infective endocarditis (IE) in patients with normal valves has increased in the last decades. Whether patients with normal valves present a similar prognosis to those with pathologic valves is unresolved. Our aim is to describe epidemiologic and clinical differences between patients with left-sided IE and normal valves and those with native pathologic valves. We analyzed 945 consecutive episodes of IE, 435 of which involved left-sided nonprosthetic IE. They were classified into 2 groups: episodes in normal valves (normal group, n=173) and episodes in pathologic valves (abnormal group, n=262). Patients in the normal group were younger, Staphylococcus aureus and Streptococcus bovis were more frequently isolated, and vegetations were more frequently found. Heart failure, septic shock, and the need for surgery or death were more common. Multivariate analysis identified the following as factors independently associated with normal valve IE: age<65 years, S bovis, S aureus, heart failure, and vegetation detection. Factors independently associated with in-hospital events included S aureus, periannular complications, heart failure, and septic shock development. In conclusion, compared with patients with abnormal valve IE, patients with IE on normal valves were younger, had a more virulent microbiological profile, developed heart failure and septic shock more frequently, needed more surgical procedures, and had worse prognosis.