Evolocumab: Considerations for the Management of Hyperlipidemia.

PURPOSE OF REVIEW: To review the efficacy, safety, pharmacology, and pharmacokinetics of evolocumab, a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor. RECENT FINDINGS: PCSK9 inhibitors are a class of lipid-lowering agents that significantly reduce low-density lipoprotein cholesterol (LDL-C) levels in patients with atherosclerotic cardiovascular disease and hyperlipidemia. Evolocumab is a monoclonal antibody that inhibits PCSK9 and has been evaluated in phase II and III studies as monotherapy, in combination with statins and other lipid-lowering therapies, in patients who are statin intolerant, and in patients with heterozygous and homozygous familial hypercholesterolemia. Data from these studies show that evolocumab significantly reduces LDL-C levels. Treatment with evolocumab also significantly improves levels of other lipid parameters (e.g., apolipoproteins A1 and B, lipoprotein(a), non-high-density lipoprotein cholesterol, and triglycerides). Recent results indicate that LDL-C reduction with evolocumab significantly reduces the risk of cardiovascular events and is also associated with atherosclerotic plaque regression. From a safety standpoint, rates of adverse events (AEs), serious AEs, and AEs leading to discontinuation were similar between evolocumab and controls in clinical trials, and no increase in AEs was observed when evolocumab was used in combination with statins. Patients with elevated LDL-C benefit from evolocumab treatment, suggesting that evolocumab could help meet an unmet medical need in high-risk patient populations with atherosclerotic cardiovascular disease and hyperlipidemia that are unable to reduce LDL-C levels sufficiently with statin therapy alone.

The Impact of the PR Interval in Patients Receiving Cardiac Resynchronization Therapy: Results From the REVERSE Study.

OBJECTIVES: This study sought to evaluate the impact of baseline PR interval on cardiac resynchronization therapy (CRT) outcomes in the REVERSE (Resynchronization Reverses Remodeling in Systolic Left Ventricular Dysfunction) study. BACKGROUND: The baseline electrocardiogram has important prognostic value to determine response to CRT. Specifically, QRS duration and morphology are strong predictors of response and outcomes; however, the prognostic importance of the PR interval is less clear. METHODS: REVERSE was a double-blinded, randomized study of CRT in mild heart failure (HF). The primary endpoint was the analysis of patients in sinus rhythm (n = 582) of the time-to-first HF hospitalization or death during the 2-year randomized period of the trial. In addition, the long-term impact of PR interval was assessed in the cohort actively on CRT during the pre-planned 5-year follow-up. Subjects were analyzed by PR interval, grouped by the median (180 ms) in 20-ms bins or as a continuous variable depending on the analysis performed. Secondary endpoints included the clinical composite score and echocardiographic measures of reverse remodeling. RESULTS: During the randomized phase of the study, CRT had similar effectiveness for both PR <180 ms (hazard ratio [HR]: 0.34) and PR >180 ms (HR: 0.57) subgroups (interaction p = 0.33). Similar results were observed when PR interval was grouped in 20-ms bins or treated as a continuous variable. In multivariable analysis of the long-term follow-up, left bundle branch block morphology, New York Heart Association functional class, HF etiology, and QRS duration, but not PR interval, predicted HF hospitalization or death. CONCLUSIONS: Baseline PR interval does not affect clinical outcomes or reverse remodeling with CRT in mild HF. (Resynchronization Reverses Remodeling in Systolic Left Ventricular Dysfunction [REVERSE]; NCT00271154).

Reduced Anticoagulant Effect of Dabigatran in a Patient Receiving Concomitant Phenytoin.

Dabigatran, a direct thrombin inhibitor, is an oral anticoagulant indicated for the prevention of stroke in patients with atrial fibrillation (AF) and for the treatment and prevention of deep vein thrombosis and pulmonary embolism. Dabigatran, as well as the other new anticoagulants-rivaroxaban, apixaban, and edoxaban-are substrates for P-glycoprotein (P-gp). Although the U.S. labeling for rivaroxaban and apixaban states to avoid concomitant use with phenytoin, a known P-gp inducer, the U.S. labeling for dabigatran and edoxaban are less clear. We describe the first case report, to our knowledge, documenting a drug interaction between phenytoin and dabigatran by using laboratory measurements of dabigatran serum concentrations. A 45-year-old African-American man was admitted to the inpatient cardiology service following defibrillations from his implantable cardioverter defibrillator. The patient was evaluated and received appropriate antitachycardia pacing for atrial tachyarrhythmias for an episode of ventricular tachycardia (VT), and antiarrhythmic therapy with sotalol was initiated to reduce both his AF and VT burden. On review of the patient's medications for potential interactions, it was discovered that the patient was taking both dabigatran and phenytoin. To determine the magnitude of this drug interaction prior to making a change in his anticoagulation regimen, a dabigatran serum concentration was measured. This concentration was undetectable, indicating that phenytoin had a significant influence on dabigatran's metabolism and that this patient was at high risk for stroke. Clinicians should be aware of this interaction between phenytoin and dabigatran as well as with all other new oral anticoagulants. In patients taking phenytoin who require an anticoagulant, only warfarin should be prescribed to minimize the risk of stroke. In addition, the prescribing information for dabigatran should be updated to include other medications that result in a significant reduction in dabigatran serum concentrations, such as phenytoin.