History of Antimicrobial Prophylaxis Protocols for Infective Endocarditis Secondary to Dental Procedures

Abstract

For several decades, the haematogenous spread of bacteria from the oral cavity has been considered a decisive factor in the pathogenesis of 10% to 15% of episodes of infective endocarditis (IE), suggesting that certain dental procedures may represent a significant risk factor [1]. Nowadays, however, this statement has its detractors; their main argument is that not all patients with heart valves infected by bacteria that typically colonize ecological niches of the oral cavity have undergone dental procedures. Furthermore, there is little evidence to date on the genetic similarity between bacteria isolated from the heart valves, from the bloodstream, and from the oral cavity of patients with IE [2,3]. Apart from its possible involvement in the development of episodes of IE, bacteraemia of oral origin has become of particular interest in the past 2 decades because it has been associated with the progression of atherosclerosis and may thus be related to ischemic processes, although the mechanism of action has not yet been fully elucidated [4-6]. A number of published clinical studies have demonstrated an association between periodontal disease and cardiovascular disease [7-9], and oral bacteria have been detected on heart valves and in atherosclerotic plaques and aortic aneurysms [10-12]. In 1935, Okell and Elliot [13] were the first authors to detect bacteraemia caused by Strepto‐ coccus species (in 64% of cases) after performing dental extractions on 138 patients. A year later, Burket and Burn [14] inoculated pigmented Serratia marcescens into the gingival sulcus of 90 patients before performing dental extractions and they subsequently isolated this bacterium in 20% of post-manipulation blood cultures. Those results confirmed that microorganisms from the oral cavity could enter the bloodstream after dental extraction. Between the mid 1930s and the early 1950s, numerous studies were published on the prevalence of post-dental extraction bacteraemia, with figures that varied between 2% and 83% [15-19]. In the early 1930s there was a growing awareness of the need for IE prophylaxis in patients with valvular heart disease undergoing certain dental manipulations, and the first guidelines recommending the use of certain sulfonamides to prevent IE of oral origin were published at the end of that decade. This chapter first provides a review of development of antimicrobial prophylaxis protocols for IE secondary to dental procedures between 1930 and 1955. Since the American Heart Associ‐ ation (AHA) published its first guideline for the prevention of IE secondary to dental proce‐ dures in 1955, several international committees formed mainly of cardiologists, infectious diseases specialists and pharmacologists have drawn up different prophylactic regimens based on findings published in the scientific literature. In the second part of this chapter we therefore review the changes in IE prophylaxis in the guidelines published by the AHA and the British Society of Antimicrobial Chemotherapy (BSAC) between 1960 and 2009, as well as those recently drawn up by other societies. Those guidelines provide a description of the susceptible patient, the at-risk dental procedures, the influence of the anaesthetic technique applied in dental treatment, the antibiotic prophylaxis protocols (antibiotics of choice, dose and route of administration) and the use of antiseptic prophylaxis.