A Single Controlled Exposure to Secondhand Smoke May Not Alter Thrombogenesis or Trigger Platelet Activation.

INTRODUCTION: Chronic secondhand smoke (SHS) exposure increases cardiovascular events, particularly acute thrombotic events. There are little human data on acute SHS exposure. The aim of this study was to determine whether a single controlled exposure of humans to SHS increased thrombogenesis. METHODS: After 6-8 hours fast, subjects (n = 50) were exposed to constant dose SHS (particulate level of 500 µg/m(3)) for 120 minutes in a temperature-regulated and ventilated, simulated bar environment. Blood was drawn before and immediately after SHS exposure for thromboelastography (TEG) and flow cytometry. Maximum clot strength (MA) was measured using TEG and platelet leukocyte aggregates (LPA) were measured as an index of platelet activation. Anti-CD 14 antibodies were used as leukocyte markers and anti-CD 41 antibodies as platelet markers for cytometry. Data were analyzed using students' t test for paired samples. RESULTS: There was no effect of acute exposure to SHS on platelet activation or thrombogenesis. Also, intra group (smokers [n = 19] and nonsmokers [n = 31]) comparisons of LPA and TEG parameters did not show changes with SHS exposure. CONCLUSIONS: While there are abundant data showing enhanced thrombogenesis and platelet activation following repeated exposure to SHS, our study suggests that a single exposure does not appear to significantly alter thrombin kinetics nor result in platelet activation. The effects of SHS on thrombogenesis might be nonlinear.

The safety and tolerability of beta blockers in heart failure with reduced ejection fraction: is the current underutilization of this evidence-based therapy justified?

INTRODUCTION: Beta blockers are one of the cornerstones for treatment of Heart Failure with Reduced Ejection fraction (HFRef), yet their use is often limited by adverse effects, either perceived or real. We performed a review of available data using PubMed.gov utilizing beta blocker, heart failure, reduced ejection fraction and safety as key words. AREAS COVERED: Several well designed, large scale randomized clinical trials including CIBS-II (bisoprolol), MERIT-HF (metoprolol succinate), and Copernicus (carvedilol) among others, have been conducted in patients with HFRef and demonstrated an improvement in cardiac mortality and morbidity. Despite the preponderance of data supporting the use of beta blockers for patients HFRef, these medications remain underutilized and/or are often prescribed at lower than recommended dosages. Some of the reluctance to embrace beta blockade may be attributed to concern on the part of both the patient and prescriber about the non-cardiac adverse effects of this class of drugs. We have reviewed several recent reviews and meta-analyses of trials of beta blocker in heart failure which have conclusively demonstrated their tolerability in the populations studied. EXPERT OPINION: In the final section of this paper we provide our opinions regarding initiating and optimizing beta blocker therapy for patients with HFRef.

Medical treatment of hypertension in patients with heart failure with preserved ejection fraction.

Heart failure with preserved ejection fraction (HFPEF) has become an increasingly common problem, accounting for as many as half of all diagnoses of heart failure. Hypertension has been shown to be a major risk factor for the development of HPEF, and the treatment of hypertension is key to both preventing the development of HFPEF as well as mitigating its impact on our health care system. While numerous studies have looked at using various classes of antihypertensive medications to treat HFPEF, there are still no well validated treatment strategies which have shown a significant mortality benefit. As a result, when choosing an antihypertensive medication to treat or prevent HFPEF, it is important to tailor the choice of antihypertensive medication to an individual patient's specific symptoms and comorbidities.