A not very NICE case of endocarditis

A 69-year-old man, previously independent and with a pre-existing metallic aortic valve, presented with a history of fevers, confusion and malaise and was diagnosed with prosthetic valve endocarditis. Blood cultures taken on presentation grew Streptococcus sanguinis and vegetations were confirmed on transoesophageal echocardiogram. He had had a dental procedure 10 days before presentation but had not received prophylactic antibiotics; he had been receiving antibiotic prophylaxis for dental treatment up until the change in NICE guidelines in 2008. He was treated with high dose antibiotics and was referred for cardiothoracic surgery, but developed a cerebrovascular event, thought to be embolic, and deteriorated and died. Given that the patient had a metallic aortic valve and poor dentition, and therefore was at increased risk of infective endocarditis, should the new guidelines have been followed so rigidly, particularly as American and European guidelines still recommend the use of antibiotic prophylaxis in this patient group?