Efficacy and safety of ticagrelor: a reversible P2Y12 receptor antagonist.

OBJECTIVE: To summarize the pharmacokinetic and pharmacodynamic properties of ticagrelor, a selective P2Y12 receptor antagonist, and evaluate its role in the treatment of patients with acute coronary syndromes (ACS). DATA SOURCES: A literature search was conducted in MEDLINE (1966-November 2009), International Pharmaceutical Abstracts (1970-November 2009), and EMBASE (1990-November 2009) using the MeSH terms and key words AZD6140, ticagrelor, P2Y12 receptor antagonist, cardiovascular disease, ACS, atherothrombosis, and platelets. STUDY SELECTION AND DATA EXTRACTION: Selected studies evaluated the pharmacology, pharmacokinetics, pharmacodynamics, safety, and efficacy of ticagrelor for the treatment of ACS. DATA SYNTHESIS: Ticagrelor selectively and reversibly blocks the P2Y12 receptor, inhibiting platelet aggregation and preventing amplification of platelet activation. Optimal dosing strategy as determined by ticagrelor's pharmacokinetic and pharmacodynamic profile is a loading dose of 180 mg followed by 90 mg by mouth twice daily. At these doses, greater platelet inhibition is observed with ticagrelor as compared to clopidogrel 75 mg once daily in both clopidogrel-experienced and -naïve patients. Studies in patients experiencing ACS concluded that ticagrelor reduced the rate of cardiovascular death, nonfatal myocardial infarction, stent thrombosis, and overall mortality compared to clopidogrel without increasing major bleeding when administered with standard therapy for ACS. There was no significant difference in the risk of stroke with ticagrelor compared to clopidogrel; however, intracranial bleeding was more common with ticagrelor. Ticagrelor is well tolerated; however, minor bleeding, dyspnea, hypotension, nausea, and ventricular pauses were reported more frequently than with clopidogrel. Reversible inhibition with ticagrelor may allow for more rapid surgical intervention after discontinuation, suggesting greater flexibility in treatment of ACS. CONCLUSIONS: Ticagrelor's improved pharmacokinetic and pharmacodynamic profile builds upon the limitations of currently available P2Y12 receptor antagonists. Ticagrelor represents a promising approach for the prevention of cardiovascular events in patients with ACS.

Baseline predictors of central aortic blood pressure: a PEAR substudy.

Elevated central systolic blood pressure (BP) increases the risk of cardiovascular events and appears superior to peripheral BP for long term risk prediction. The objective of this study was to identify demographic and clinical factors associated with central pressures in patients with uncomplicated hypertension. We prospectively examined peripheral BP, central aortic BP, and arterial wall properties and wave reflection in 57 subjects with uncomplicated essential hypertension in the Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR) Study. Significant predictors of central SBP included height, smoking status, heart rate (HR), and peripheral systolic BP (SBP), while central diastolic BP (DBP) was explained by peripheral DBP and HR. These variables accounted for nearly all of the variability in central SBP and central DBP (R(2) = 0.94 and R(2) = 0.98, respectively). Central pulse pressure variability was largely explained by gender, ex-smoking status, HR, peripheral SBP, and peripheral DBP (R(2) = 0.94). Central augmented pressure had a direct relationship with smoking status, peripheral SBP, and duration of hypertension, whereas it was indirectly related to height, HR, and peripheral DBP. Easily obtainable demographic and clinical factors are associated with central pressures in essential hypertensive persons. These relationships should be considered in future studies to improve assessment of BP to reduce cardiovascular risk and mortality.

Management of hypertension with fixed-dose triple-combination treatments.

The objective of this review is to evaluate the role of fixed-dose triple-combination therapy for the management of hypertension. An assessment of clinical trials showed that half the patients with hypertension have uncontrolled blood pressure (BP), with underlying factors including therapeutic inertia and poor patient adherence. Many patients will require three antihypertensive agents to achieve BP goals, and current guidelines recommend combining drugs with complementary mechanisms of action. Three single-pill triple-combination treatments are available and each includes an agent affecting the renin-angiotensin-aldosterone pathway (either a direct renin inhibitor or an angiotensin II receptor blocker) in combination with a calcium channel blocker and diuretic. These triple-combination therapies consistently demonstrated significantly greater BP reduction relative to the component dual combinations, with BP reductions documented across a range of patient populations. Triple-combination treatments were well tolerated in all clinical trials reviewed. The use of single-pill, triple-combination antihypertensive therapy has been shown to be an effective, well-tolerated, and convenient treatment strategy that can help patients achieve BP control.

The evolving landscape of RAAS inhibition: from ACE inhibitors to ARBs, to DRIs and beyond.

Chronic renin-angiotensin-aldosterone system (RAAS) activation has far-reaching effects on cardiometabolic risk and is a substantial contributor to cardiovascular (CV) disease and renal dysfunction. The vascular effects of sustained RAAS activation are associated with hemodynamic imbalances, as well as inflammatory stimulation and prothrombotic processes that lead to fibrosis, endothelial dysfunction and cellular remodeling. RAAS inhibition therapies, which include the use of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers and more recently, direct renin inhibitors, have been used in clinical practice for more than 30 years. Our understanding of how these drugs work, alone and in combination, has contributed to an expanding landscape of treatment options and established RAAS inhibition as essential for reducing the risk of CV and renal disease. This perspective provides a historical overview of how RAAS inhibitors have evolved to their present-day status and will discuss recently discovered functions for components of this complicated and powerful regulatory system.

Dapagliflozin: a novel sodium-glucose cotransporter type 2 inhibitor for the treatment of type 2 diabetes mellitus.

The prevalence of diabetes mellitus has grown to staggering numbers, and its incidence is expected to rise in the next 2 decades. The need for novel approaches to treat hyperglycemia cannot be ignored. Current agents have been shown to modestly improve glycemia and in some cases prevent complications of diabetes, but they become less effective over time and are often accompanied by undesirable adverse effects. Dapagliflozin is the lead agent in a new class of oral antidiabetic agents known as sodium-glucose cotransporter type 2 (SGLT2) inhibitors, which represent a novel approach to the management of type 2 diabetes mellitus. By selectively and reversibly blocking the SGLT2 receptor, dapagliflozin prevents the reabsorption of glucose at the renal proximal tubule. Phase II and III clinical trials have demonstrated that dapagliflozin is a safe and effective method for treating type 2 diabetes. Dapagliflozin produces a sustained, dose-dependent reduction in plasma glucose levels while simultaneously improving insulin secretion and sensitivity. Over 12-24 weeks, reductions in hemoglobin A(1c) ranged from 0.54-0.89% when dapagliflozin was administered once/day (either as monotherapy or add-on therapy to oral antidiabetic drugs with or without insulin) to patients with type 2 diabetes. Therapy with dapagliflozin also results in a mild osmotic-diuretic effect that may account for decreases in total body weight (~2-3 kg) and blood pressure (systolic 2-5 mm Hg, diastolic 1.5-3 mm Hg), and increases in hematocrit (1-2%). Dapagliflozin has a favorable safety profile, with the rates of hypoglycemia similar to those of placebo. Genital and urinary tract infections were more commonly reported in patients taking dapagliflozin (2-13%) than those taking placebo (0-8%). Dapagliflozin does not appear to cause electrolyte disturbances, hepatotoxicity, or nephrotoxicity. Results from clinical trials have been promising, and well-designed clinical programs that address the long-term safety and efficacy of dapagliflozin are under way.

Carvedilol reduces aortic wave reflection and improves left ventricular/vascular coupling: a comparison with atenolol (CENTRAL Study).

Blood pressure (BP) characteristics, such as central aortic pressure and arterial stiffness, independently predict cardiovascular events. The effects of pharmacologically dissimilar ß-blockers on these properties have not been fully elucidated. Patients with essential hypertension and without significant concomitant cardiovascular disease were randomly assigned to controlled-release carvedilol, force-titrated to 80 mg (n=22), or atenolol, force-titrated to 100 mg (n=19); each was given once daily for 4 weeks. Baseline characteristics were similar. At the end of week 4, atenolol and carvedilol reduced central and brachial systolic and diastolic BP to a similar extent. Central augmentation index was increased in atenolol-treated patients but not carvedilol-treated patients (atenolol 4.47% vs carvedilol -0.68%; P=.04). Mean augmented central aortic pressure increased slightly during atenolol treatment (+1.1 mm Hg) but decreased slightly during carvedilol treatment (-1.1 mm Hg), although the difference in these changes was not statistically significant (P=.23). Pulse pressure amplification was reduced more with atenolol at week 4 (atenolol -10.7% vs carvedilol -1.8%; P=.02). Therefore, we conclude that carvedilol results in more favorable pulse pressure amplification and augmentation index by increasing arterial compliance and reducing the magnitude of wave reflection, respectively, compared with atenolol.