Hypertrophic obstructive cardiomyopathy and infective endocarditis: A report of seven cases and a review of the literature

Abstract

Seven cases of infective endocarditis (IE) in patients with hypertrophic obstructive cardiomyopathy (HOCM) are presented in this report. The previous literature is critically reviewed, and the following points are discussed: (a) IE complicates HOCM in 5-9% of cases; (b) anatomical and haemodynamic alterations of HOCM cause microtraumas on heart valves and the endocardium; the resulting endocardial lesions represent sites for bacterial seeding as well as other congenital or acquired heart disease; (c) prognosis is worse in patients with IE associated with HOCM than in patients with IE alone or associated with congenital heart disease; (d) the most frequently isolated organisms are saprophytes; (e) most patients were exposed to bacteraemias before the onset of IE.

Infective Endocarditis in Hypertrophic Cardiomyopathy

“…In view of our finding that each of the 10 study patients with endocarditis had left ventricular outflow obstruction, we also verified the frequency of outflow obstruction in the 33 HCM patients with infective endocarditis reported in the English language literature during the last 20 years [3][4][5][22][23][24][25][26][27][28][29][30] ; each had outflow obstruction under basal conditions.…”

“…[3][4][5] The frequency of endocarditis in the overall HCM population, however, remains unknown and the features of the disease associated with an increased risk of developing this complication have never been systematically investigated. Therefore it is not clear whether all patients or only certain subgroups, within the broad clinical spectrum of HCM, require antibiotic prophylaxis for infective endocarditis.…”

“…These findings prompted us to verify the functional profile of the HCM patients with infective endocarditis previously reported in the literature. During the last 2 decades, 33 HCM patients with endocarditis were reported in the English language literature [3][4][5][22][23][24][25][26][27][28][29][30] ; each had the obstructive form of the disease. Therefore, on the basis of our findings, as well as our focused analysis of the literature, HCM patients with left ventricular outflow obstruction under basal conditions would appear to be the ones at significant risk for developing endocarditis and thus the subgroup that requires antibiotic prophylaxis.…”

“…Indeed, the degree of incompetence of the damaged valve, which is the principal determinant of clinical course in endocarditis, is not necessarily severe in all patients. The particularly high morbidity and mortality generally reported for endocarditis in HCM is probably due to the fact that the literature is based on case reports [3][4][5][22][23][24][25][26][27][28][29][30] and thus is probably skewed toward those patients posing the most challenging clinical problems.…”

“…1,2 The literature on endocarditis in HCM, however, is scarce and virtually confined to reports of patients who developed this complication. [3][4][5] Consequently, the risk of endocarditis in the overall HCM population remains undefined. In addition, because of the broad clinical spectrum of HCM, 6 -8 it is unclear whether antibiotic prophylaxis should be recommended to all patients or only to certain subgroups.…”