Effect of vancomycin minimal inhibitory concentration on the outcome of methicillin-susceptible Staphylococcus aureus endocarditis.

BACKGROUND: Staphylococcus aureus endocarditis has a high mortality rate. Vancomycin minimum inhibitory concentration (MIC) has been shown to affect the outcome of methicillin-resistant S. aureus bacteremia, and recent data point to a similar effect on methicillin-susceptible S. aureus bacteremia. We aimed to evaluate the effect of vancomycin MIC on left-sided S. aureus infective endocarditis (IE) treated with cloxacillin. METHODS: We analyzed a prospectively collected cohort of patients with IE in a single tertiary-care hospital. Vancomycin, daptomycin, and cloxacillin MIC was determined by E-test. S. aureus strains were categorized as low vancomycin MIC (<1.5 µg/mL) and high vancomycin MIC (≥1.5 µg/mL). The primary endpoint was in-hospital mortality. RESULTS: We analyzed 93 patients with left-sided IE treated with cloxacillin, of whom 53 (57%) had a vancomycin MIC < 1.5 µg/mL and 40 (43%) a vancomycin MIC ≥ 1.5 µg/mL. In-hospital mortality was 30% (n = 16/53) in patients with a low vancomycin MIC and 53% (n = 21/40) in those with a high vancomycin MIC (P = .03). No correlation was found between oxacillin MIC and vancomycin or daptomycin MIC. Logistic regression analysis showed that higher vancomycin MIC increased in-hospital mortality 3-fold (odds ratio, 3.1; 95% confidence interval, 1.2-8.2) after adjustment for age, year of diagnosis, septic complications, and nonseptic complicated endocarditis. CONCLUSIONS: Our results indicate that vancomycin MIC could be used to identify a subgroup of patients with methicillin-susceptible S. aureus IE at risk of higher mortality. The worse outcome of staphylococcal infections with a higher vancomycin MIC cannot be explained solely by suboptimal pharmacokinetics of antibiotics.

Relation of left ventricular hypertrophy to regional cerebral blood flow: single photon emission computed tomography abnormalities in essential hypertension.

Several reports have shown that left ventricular hypertrophy (LVH) is an independent predictor of acute cerebrovascular events. The aim of the present study was to investigate the relationship between LVH and cerebral blood flow in middle-aged patients with essential hypertension. Forty never-treated hypertensive patients (24 men, 16 women, aged 50-60 years) without clinical evidence of target organ damage were studied. Regional cerebral blood flow was measured by means of single photon emission computed tomography of the brain. Twenty-nine patients showed echocardiographic criteria of LVH; 11 patients did not show this feature. No differences were found in regional cerebral blood flow ratio of all brain areas studied between hypertensives with or without LVH except for the striatum area. The regional cerebral blood flow ratio was significantly reduced in the striatum region of hypertensive patients with LVH, compared with patients without LVH (91.5+/-7.4 vs 98.1+/-8.3; P=.023). This relationship remained significant after adjusting for blood pressure. The authors conclude that the presence of LVH in middle-aged patients with essential hypertension is associated with a reduction of regional cerebral blood flow in the striatum area.

Infective endocarditis in hypertrophic cardiomyopathy: A multicenter, prospective, cohort study.

Infective endocarditis (IE) complicating hypertrophic cardiomyopathy (HCM) is a poorly known entity. Although current guidelines do not recommend IE antibiotic prophylaxis (IEAP) in HCM, controversy remains.This study sought to describe the clinical course of a large series of IE HCM and to compare IE in HCM patients with IE patients with and without an indication for IEAP.Data from the GAMES IE registry involving 27 Spanish hospitals were analyzed. From January 2008 to December 2013, 2000 consecutive IE patients were prospectively included in the registry. Eleven IE HCM additional cases from before 2008 were also studied. Clinical, microbiological, and echocardiographic characteristics were analyzed in IE HCM patients (n = 34) and in IE HCM reported in literature (n = 84). Patients with nondevice IE (n = 1807) were classified into 3 groups: group 1, HCM with native-valve IE (n = 26); group 2, patients with IEAP indication (n = 696); group 3, patients with no IEAP indication (n = 1085). IE episode and 1-year follow-up data were gathered.One-year mortality in IE HCM was 42% in our study and 22% in the literature. IE was more frequent, although not exclusive, in obstructive HCM (59% and 74%, respectively). Group 1 exhibited more IE predisposing factors than groups 2 and 3 (62% vs 40% vs 50%, P < 0.01), and more previous dental procedures (23% vs 6% vs 8%, P < 0.01). Furthermore, Group 1 experienced a higher incidence of Streptococcus infections than Group 2 (39% vs 22%, P < 0.01) and similar to Group 3 (39% vs 30%, P = 0.34). Overall mortality was similar among groups (42% vs 36% vs 35%, P = 0.64).IE occurs in HCM patients with and without obstruction. Mortality of IE HCM is high but similar to patients with and without IEAP indication. Predisposing factors, previous dental procedures, and streptococcal infection are higher in IE HCM, suggesting that HCM patients could benefit from IEAP.

Correlation between silent cerebral white matter lesions and left ventricular mass and geometry in essential hypertension.

BACKGROUND: It has been proposed that concentric left ventricular hypertrophy (LVH) is related to a worse degree of target organ damage in hypertensives with this feature than in those without. Moreover, the presence of cerebral white matter lesions (WMLs) is considered to be an early marker of brain damage in essential hypertension. The aim of this study was to assess the association between the presence of silent WMLs and left ventricular mass and geometry in middle-aged individuals with hypertension that had never been treated. METHODS: A total of 62 patients (39 men, 23 women, aged 50 to 60 years, mean age 54.4 +/- 3.2 years) with never-treated essential hypertension and without clinical evidence of target organ damage were studied. All patients underwent brain magnetic resonance imaging and were classified into two groups according to the presence or absence of WMLs. Echocardiography measuring posterior wall thickness (PWT), interventricular septum thickness (IVST) and left ventricular end-diastolic diameter (LVEDD) was also performed. Left ventricular mass index (LVMI) was calculated using the Penn convention criteria, and relative wall thickness ratio (RWT) was estimated by the standard formula: 2 x PWT/LVEDD. RESULTS: Hypertensive patients with WMLs exhibited significantly higher PWT, IVST, LVMI, and RWT when compared with hypertensive patients without WMLs. In addition, 23 of 26 hypertensive patients with WMLs showed echocardiographic criteria for LVH that was significantly higher than that observed in hypertensive patients without WMLs (21 of 36; P = .01). Concentric hypertrophy (LVH and RWT > or = 0.45) was present in 14 hypertensive patients with WMLs and in only four patients without WMLs (P = .002). CONCLUSION: There is a close association between cerebral WMLs and concentric LVH in asymptomatic middle-aged hypertensive patients, independent of blood pressure values.