Publications of the Week, December 12

Below are the articles selected as suggested reading for this week by editors from McMaster University.

Statin lipid-lowering therapy for primary prevention of CVD

The authors of the US Preventative Task Force have provided a recommendation for the use of statin lipid-lowering therapy among patients with risk factors for cardiovascular disease (CVD) but without CVD history (primary prevention).

The recommendation to use statins is based on two factors. The first is the presence of known risk factors: diabetes mellitus, smoking, hypertension, or hyperlipidemia (levels of low-density lipoprotein cholesterol [LDL-C] >130 mg/dL or high-density lipoprotein cholesterol [HDL-C] <40 mg/dL; using the conversion rate of 1 mmol/L = 38.7 mg/dL, this equals approximately >3.36 mmol/L of LDL-C and <1.03 mmol/L of HDL-C). The second element is the calculated 10-year risk of CVD events (coronary or stroke-related death, nonfatal myocardial infarction, or nonfatal stroke). Such calculators consider age, race, total cholesterol and HDL-C, smoking, current blood pressure, and antihypertensive treatment.

The authors recommend use of low- to moderate-dose statins for adults aged 40 to 75 years with ≥10% 10-year CVD event risk and suggest such treatment for those with a 7.5% to 10% risk.

The calculator is available as a downloadable spreadsheet and mobile apps from my.americanheart.org/cvriskcalculator. The web version can be accessed at tools.acc.org/ASCVD-Risk-Estimator. (To convert mg/dL into mmol/L, divide the value by 38.7 or use an online conversion tool, such as onlineconversion.com.)

Ablation for patients with nonparoxysmal atrial fibrillation

Patients with persistent or long-standing atrial fibrillation may benefit from treatment with radiofrequency catheter ablation (RFCA) in comparison to antiarrhythmic drugs.

Management of atrial fibrillation may rely on rate or rhythm control. Rhythm control may include medication, cardioversion, or the newer technique of RFCA (elimination, via transvenously inserted catheters, of the pulmonary veins or left atrial tissue responsible for generation or propagation of atrial fibrillation).

The authors of this Cochrane review analyzed 3 trials including 261 patients with persistent (>7 days) or long-standing (>1 year) atrial fibrillation. The probability of not having an episode of atrial fibrillation after 1 year of treatment was ~35% in the group treated with antiarrhythmic drugs versus ~65% if treated with RFCA. The need for cardioversion during that period occurred in 42% and 26% of patients, respectively, and hospitalization for cardiac problems, in 18% versus 5%. The probability of severe bradycardia or need for pacemaker was observed in 5% versus 1% of patients. The incidence of complications was low.

The authors observe that the confidence in the benefit of RFCA is reduced due to the relatively small number of participants and a still relatively low probability of success regardless of treatment offered.

Updates in gout management

Clinical practice guidelines (CPGs) in both Europe and North America have recently provided directions for management of gout, a disease diagnosed at some stage in 4% of population.

The guidelines provided by the American College of Physicians recommend that a number of choices are available and likely equally efficacious for the treatment of acute gout: nonsteroidal anti-inflammatory drugs, colchicine, glucocorticosteroids. Authors of these CPGs recommend also that low-dose rather than high-dose colchicine is used during acute attacks, ie, 1.2 mg followed by 0.6 mg after 1 hour (similar efficacy, less diarrhea: 23% in the low-dose group vs 77% with the higher dose). Another recommendation is issued against the use of urate-lowering therapy in most patients after the first gout attack or in patients with infrequent attacks (<2 attacks/year). Other observations point to the unclear way in which uric-acid lowering translates into the reduction of gout attack frequency (likely no lowering for the first 6 months, probably some after 1 year) and lack of evidence suggesting differences among xanthine oxidase inhibitors (allopurinol, febuxostat). Prophylactic low-dose colchicine (0.6 mg twice a day) or a low-dose nonsteroidal anti-inflammatory drug reduces the frequency of gout attacks once uric-acid lowering therapy is initiated and could be used for weeks or months.

The European CPGs provide more details about the doses (eg, dose of colchicine during an acute attack: 1 mg followed 1 hour later by 0.5 mg; dose of oral steroids: 30-35 mg of prednisolone equivalent for 3 to 5 days; suggested dose of prophylactic colchicine: 0.5-1 mg/day). The authors recommend initiation of urate-lowering therapy (initially with allopurinol) in patients with recurrent flares, tophi, arthropathy, or renal stones. They also recommend such therapy in those aged <40 years or with a high uric acid level (>8 mg/dL, or 480 µmol/L). Pegloticase is described as of use in chronic, debilitating, and treatment-refractory gout (high frequency of adverse events and a very high cost; this drug was not mentioned in the American College of Physicians guidelines).