The unique clinical features and outcome of infectious endocarditis and vertebral osteomyelitis co-infection

Abstract

Objective: The clinical significance of vertebral osteomyelitis and infectious endocarditis co-infection is unclear. This study investigates the rate, clinical features, and outcome of vertebral osteomyelitis with and without concomitant infectious endocarditis.

Methods: A retrospective study of all cases of osteomyelitis with spinal imaging (n = 176), from January 2007 to April 2013, that were diagnosed as vertebral osteomyelitis. Sixty-two patients with spontaneous vertebral osteomyelitis were identified after excluding postsurgical, decubitus ulcers and spinal metastases. Seventeen (27%) were identified with concomitant infectious endocarditis.

Results: All patients presented with back pain and 59% were diagnosed with infectious endocarditis subsequent to vertebral osteomyelitis. Distinguishing features among the co-infection group include the increased use of transesophageal echocardiography (94% vs 58%, P = .004), predisposing cardiac conditions (59% vs 16%, P = .001), and Gram-positive bacteremia, of which Streptococcus sp. and Enterococcus sp. were more common (35% vs 11%, P = .026). Adverse neurologic events were increased significantly in the co-infection group (59% vs 22%, P = .006). On transesophageal echocardiography, 88% of co-infection patients had highly mobile vegetations, 9 of which measured 10 mm or more. The overall mortality was 41% and 29% in the co-infection and lone vertebral osteomyelitis groups, respectively (P = .356). One-year mortality was identical for both groups at 24% (P = .999), and higher than previously reported (11.3% for lone vertebral osteomyelitis).

Conclusions: Patients with vertebral osteomyelitis, in whom infectious endocarditis is not excluded, are at increased risk for adverse neurologic events and mortality. The prompt diagnosis of infectious endocarditis, and associated high-risk features that may benefit from surgical intervention, require early evaluation by transesophageal echocardiography.

Keywords: Endocarditis; Infective endocarditis; Spine infections; Spondylitis; Spondylodiscitis; Vertebral osteomyelitis.