Gastrointestinal bleeding after continuous-flow left ventricular device implantation: review of pathophysiology and management.

Gastrointestinal bleeding is one of the most common complications in patients with continuous-flow left ventricular assist devices. Though the exact pathophysiology is still unclear, continuous-flow physiology, acquired Von Willebrand disease, and formation of arteriovenous malformations in the gastrointestinal tract are implicated. An individualized plan of endoscopic therapy and anticoagulation management is required when caring for these patients.

Acute coronary syndrome in patients with diabetes mellitus: perspectives of an interventional cardiologist.

Diabetes mellitus (DM) is well known to be a coronary artery disease risk equivalent but the cellular mechanism is not completely understood. Recently, virtual histology intravascular ultrasound has demonstrated that patients with DM tend to have a higher occurrence of vulnerable plaques as compared with patients without DM. Insulin-sensitizing agents, such as metformin, have been shown to have limited cardioprotective effects, whereas thiazolidinediones, such as rosiglitazone, have been reported to have possible deleterious effects on cardiovascular mortality in a meta-analysis; however, limited data exist. In contrast, pioglitazone has been reported to have a significant benefit in patients with type 2 DM with acute coronary syndrome (ACS). Animal and human studies have demonstrated the myocardial protective effects of incretins and hold promise in reducing the incidence of major adverse cardiac events in patients with DM. Moreover, in addition to aspirin, the early use of potent antiplatelet agents, such as prasugrel and intravenous glycoprotein IIb-IIIa inhibitors, in patients with DM presenting with ACS is crucial for reducing cardiovascular events in most patients. Thus, patients with DM deserve special attention in global risk factor reduction and development of newer therapeutic agents to improve glycemic control while minimizing or reducing cardiovascular events. This article focuses on ACS in patients with DM, the pathophysiology of "vulnerable blood" in patients with DM, and newer treatment strategies to improve outcomes in this high-risk patient population.

Antihypertensive treatment and secondary prevention of cardiovascular disease events among persons without hypertension: a meta-analysis.

CONTEXT: Cardiovascular disease (CVD) risk increases beginning at systolic blood pressure levels of 115 mm Hg. Use of antihypertensive medications among patients with a history of CVD or diabetes and without hypertension has been debated. OBJECTIVE: To evaluate the effect of antihypertensive treatment on secondary prevention of CVD events and all-cause mortality among persons without clinically defined hypertension. DATA SOURCES: Meta-analysis with systematic search of MEDLINE (1950 to week 3 of January 2011), EMBASE, and the Cochrane Collaboration Central Register of Controlled Clinical Trials and manual examination of references in selected articles and studies. STUDY SELECTION: From 874 potentially relevant publications, 25 trials that fulfilled the predetermined inclusion and exclusion criteria were included in the meta-analysis. DATA EXTRACTION: Information on participant characteristics, trial design and duration, treatment drug, dose, control, and clinical events were extracted using a standardized protocol. Outcomes included stroke, myocardial infarction (MI), congestive heart failure (CHF), composite CVD outcomes, CVD mortality, and all-cause mortality. RESULTS: Compared with controls, participants receiving antihypertensive medications had a pooled relative risk of 0.77 (95% confidence interval [CI], 0.61 to 0.98) for stroke, 0.80 (95% CI, 0.69 to 0.93) for MI, 0.71 (95% CI, 0.65 to 0.77) for CHF, 0.85 (95% CI, 0.80 to 0.90) for composite CVD events, 0.83 (95% CI, 0.69 to 0.99) for CVD mortality, and 0.87 (95% CI, 0.80 to 0.95) for all-cause mortality from random-effects models. The corresponding absolute risk reductions per 1000 persons were -7.7 (95% CI, -15.2 to -0.3) for stroke, -13.3 (95% CI, -28.4 to 1.7) for MI, -43.6 (95% CI, -65.2 to -22.0) for CHF events, -27.1 (95% CI, -40.3 to -13.9) for composite CVD events, -15.4 (95% CI, -32.5 to 1.7) for CVD mortality, and -13.7 (95% CI, -24.6 to -2.8) for all-cause mortality. Results did not differ according to trial characteristics or subgroups defined by clinical history. CONCLUSIONS: Among patients with clinical history of CVD but without hypertension, antihypertensive treatment was associated with decreased risk of stroke, CHF, composite CVD events, and all-cause mortality. Additional randomized trial data are necessary to assess these outcomes in patients without CVD clinical recommendations.

Synthesis, relaxometric and photophysical properties of a new pH-responsive MRI contrast agent: the effect of other ligating groups on dissociation of a p-nitrophenolic pendant arm.

Two gadolinium(III) chelates, GdNP-DO3A (1-methlyene-(p-NitroPhenol)-1,4,7,10-tetraazacycloDOdecane-4,7,10-triAcetate) and GdNP-DO3AM (1-methlyene(p-NitroPhenol)-1,4,7,10-tetraazacycloDOdecane-4,7,10-triacetAMide), containing a single nitrophenolic pendant arm plus either three acetate or three amide pendant arms were synthesized and characterized. The properties of the gadolinium, terbium, and dysprosium complexes of these ligands were examined as a function of pH. The extent and mechanism of the changes in water relaxivity with pH of each gadolinium complex was found to differ substantially for the two complexes. The water relaxivity of Gd(NP-DO3A) increases from 4.1 mM(-1) s(-1) at pH 9 to 7.0 mM(-1) s(-1) at pH 5 as a result of acid-catalyzed dissociation of the nitrophenol from the lanthanide. The nitrophenol group in Gd(NP-DO3AM) does not dissociate from the metal center even at pH 5; therefore, the very modest increase in relaxivity in this complex must be ascribed to an increase in prototropic exchange rate of the bound water and/or phenolic protons.