Burden of infective endocarditis in an Australian cohort of people who inject drugs.

BACKGROUND: Infective endocarditis (IE) results in substantial morbidity and mortality in people who inject drugs (PWID). AIMS: To describe the burden of IE and its outcomes in PWID. METHODS: Retrospective cohort study of adults admitted to a tertiary referral centre in Melbourne, Australia, with IE due to injection drug use from 1997 to 2015. RESULTS: Ninety-seven PWID with 127 episodes of IE were identified with a median acute inpatient stay of 37 days (1-84). Admission to an intensive care unit was required in 67/127 (53%) episodes. Twenty-seven percent (34/127) of episodes occurred in patients with a previous episode of endocarditis. One third (43/127, 34%) of episodes involved left-sided cardiac valves. Antimicrobial treatment was completed in 88 (70%) episodes. Valve surgery was performed in 25/127 (20%) episodes. Predictors of surgery in univariable analysis were left-sided cardiac involvement (risk ratio (RR) 6.0), severe valvular regurgitation (RR 2.6) and cardiac failure (RR 2.2) (all P < 0.005). Twenty (16%) episodes resulted in death. Predictors of mortality on univariable analysis were left-sided cardiac involvement (RR 6.4), and not completing treatment (RR 0.12; both P < 0.001). The average estimated cost per episode was AU$74 168. CONCLUSIONS: IE causes a considerable burden of disease in PWID, with significant healthcare utilisation and cost. Surgery and death are not infrequent complications. In addition to ensuring completion of antimicrobial therapy, strategies such as opioid maintenance programmes may be useful in improving health outcomes for PWID.

Abnormal left ventricular contractile response to exercise in the absence of obstructive coronary artery disease is associated with resting left ventricular long-axis dysfunction.

BACKGROUND: The etiology of reduced left ventricular (LV) ejection fraction after exercise, without obstructive coronary artery disease or other established causes, is unclear. The aims of this study were to determine whether patients undergoing treadmill stress echocardiography with this abnormal LV contractile response to exercise (LVCRE) without established causes have resting LV long-axis dysfunction or microvascular dysfunction and to determine associations with this abnormal LVCRE. METHODS: Of 5,275 consecutive patients undergoing treadmill stress echocardiography, 1,134 underwent cardiac computed tomography angiography or invasive angiography. Having excluded patients with obstructive coronary artery disease, hypertensive response, submaximal heart rate response, resting LV ejection fraction < 50%, and valvular disease, 110 with "abnormal LVCRE" and 212 with "normal LVCRE" were analyzed. Resting mitral annular velocities were measured to assess LV long-axis function. Myocardial blush grade and corrected Thrombolysis In Myocardial Infarction frame count were determined angiographically to assess microvascular function. RESULTS: Comparing normal LVCRE with abnormal LVCRE, age (mean, 59.7 ± 11.1 vs 61.4 ± 10.0 years), hypertension (53% vs 55%), diabetes (16% vs 20%), and body mass index (mean, 29.1 ± 5.4 vs 29.5 ± 6.4 kg/m(2)) were similar (P > .05). Abnormal LVCRE had reduced resting LV long-axis function with lower septal (mean, 6.1 ± 1.9 vs 7.7 ± 2.2 cm/sec) and lateral (mean, 8.1 ± 2.9 vs 10.4 ± 3.0 cm/sec) e' velocities (P < .001) and larger resting left atrial volumes (mean, 37.3 ± 10.1 vs 31.1 ± 7.2 mL/m(2), P < .001). On multivariate analysis, female gender (odds ratio [OR], 1.21; 95% confidence interval [CI], 1.15-1.99; P < .001), exaggerated chronotropic response (OR, 1.49; 95% CI, 1.09-2.05; P < .001), resting left atrial volume (OR, 2.38; 95% CI, 1.63-3.47; P < .001), and resting lateral e' velocity (OR, 1.70; 95% CI, 1.22-2.49; P = .003) were associated with abnormal LVCRE, but not myocardial blush grade or corrected Thrombolysis In Myocardial Infarction frame count. CONCLUSIONS: An abnormal LVCRE in the absence of established causes is associated with resting LV long-axis dysfunction and is usually seen in women.

Transthoracic echocardiography is still useful in the initial evaluation of patients with suspected infective endocarditis: evaluation of a large cohort at a tertiary referral center.

OBJECTIVES: To examine the sensitivity of contemporary transthoracic echocardiography (TTE) for the detection of vegetation, abscess cavity, or prosthetic valve dehiscence (Vg) in patients with suspected infective endocarditis (IE) and to identify whether a relatively normal initial TTE finding can be effectively used as a rule out test, obviating the need for transesophageal echocardiography (TEE). PATIENTS AND METHODS: We evaluated clinical, microbiological, and echocardiographic data for all patients with suspected IE referred for both TTE and TEE between January 1, 2005, and December 31, 2010. Patients were stratified into 3 groups by baseline TTE findings: negative TTE (native valves with less than or equal to mild regurgitation and no Vg), equivocal TTE (no Vg but prosthetic valve or greater than mild native valvular regurgitation), and positive TTE (Vg detected). RESULTS: We studied 622 consecutive patients (68% male; mean ± SD age, 62 ± 17 years), including 256 with Staphylococcus aureus bacteremia (SAB). The presence of Vg was confirmed by TEE in 141 patients (23%). The TTE had low sensitivity for the detection of Vg (58%). A total of 271 patients (44%) had an initial negative TTE. Of these, TEE demonstrated Vg in only 8 patients (negative predictive value [NPV] of negative TTE, 97%). The negative TTE group included 132 patients with SAB, only 6 of whom had Vg (NPV, 95%). Of 265 patients with equivocal TTE, Vg was demonstrated in 51 (19%). CONCLUSION: In a hospital population with clinically suspected IE, TTE had low sensitivity for the detection of Vg; however, a negative initial TTE was a common finding, with a high NPV, even in the setting of SAB. A TEE may be avoided in many patients with suspected IE.