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

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.