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Less than half of patients with atrial fibrillation (AF) at the highest risk of stroke were prescribed an oral anticoagulant for prevention, a recent study of outpatient cardiology practices found.

Using 2008 to 2012 data from PINNACLE, the American College of Cardiology's quality improvement registry comprised of 429,417 patients with AF treated by cardiovascular specialists at 144 U.S. practices, researchers examined the number of prescriptions written for oral anticoagulants. Results were published online on March 16 by JAMA Cardiology.

The primary outcome was treatment with warfarin, dabigatran, or rivaroxaban, the FDA-approved oral anticoagulants for stroke prevention during the study time frame. For patients not receiving anticoagulant therapy, researchers determined whether they were treated with an antiplatelet agent (aspirin alone or aspirin plus a thienopyridine) or received neither therapy.

In total, 192,600 patients, or 44.9%, were prescribed an oral anticoagulant (90.3% warfarin, 7.7% dabigatran, and 2.0% rivaroxaban). As for antiplatelets, 111,134 patients (25.9%) were prescribed aspirin only and 23,454 patients (5.5%) were prescribed aspirin plus a thienopyridine. No antithrombotic therapy was prescribed in 102,229 patients (23.8%).

Because researchers only used data from each patient's index visit, they conducted a sensitivity analysis and found that 4,859 patients (2.1%) who were not prescribed an anticoagulant at baseline received a prescription during a follow-up visit within 1 year. The median practice treatment prevalence with anticoagulant therapy was 51.7%, (interquartile range, 37.7% to 58.3%).

Specialists were more likely to prescribe an oral anticoagulant as the number of stroke risk factors increased as measured by the CHADS2 and CHA2DS2-VASc scores. Patients with a CHADS2 score of 3 and a CHA2DS2-VASc score of 5 were most often prescribed anticoagulants (50.6% and 49.7%, respectively). Each 1-point increase in either risk score was associated with about 15% greater adjusted odds of oral anticoagulant prescription. However, researchers observed a plateau effect, as patients with a CHADS2 score exceeding 3 or a CHA2DS2-VASc score exceeding 4 were often not prescribed anticoagulants. Less than half of all higher-risk patients received anticoagulant prescriptions.

The reasons for these findings are unknown but may involve concerns regarding bleeding risk, and practice patterns may have changed since the study time frame because 4 non-vitamin K antagonist oral anticoagulants are now FDA-approved, the study authors noted.

They noted additional limitations to their study, such as how the registry does not provide enough information to calculate bleeding risk. In addition, researchers excluded 28,088 patients on the registry who were not candidates for antiplatelet or anticoagulant therapy, but specific data for the exact reasons for contraindication were unavailable.

According to an accompanying editorial, "The data ... make an important contribution and help highlight that significant opportunity to improve care exists among many outpatient practices, such as those participating in the PINNACLE Registry."

Now that these quality gaps have been documented, next steps should involve quality improvement, the editorial stated. Possible interventions include configuring electronic health records to remind clinicians when a patient has an indication for oral anticoagulation and providing better patient education, as survey data suggest that only 64% of patients with AF understand their increased risk for stroke, the editorialists wrote.

A recent large trial of intermediate-risk patients found reductions in cardiovascular events associated with statins but not with hypertension drugs.

The trial included 12,705 people from 21 countries who did not have cardiovascular disease and were at intermediate risk of cardiovascular events. Studied outcomes were a composite of death from cardiovascular nonfatal myocardial infarction, or nonfatal stroke (first outcome), and a composite of those events plus revascularization, heart failure, and resuscitated cardiac arrest (second outcome). In a 2-by-2 factorial process, participants were randomly assigned to 10 mg of rosuvastatin per day or placebo and 16 mg candesartan per day and 12.5 mg of hydrochlorothiazide per day or placebo. Median follow-up was 5.6 years. Results were published by the New England Journal of Medicine on April 2.

The mean blood pressure of all patients at baseline was 138.1/81.9 mm Hg. Patients who received the blood pressure medications had a 6.0/3.0-mm Hg greater drop than the placebo group. Overall, the treated group did not have a significant reduction in studied outcomes compared to the placebo group. However, those in a prespecified subgroup based on systolic blood pressure (>143.5 mm Hg) had significantly lower rates of the cardiovascular events if they were on active treatment.

An analysis of the cholesterol treatment found that mean LDL was 26.5% lower in the rosuvastatin group than the placebo group. The rosuvastatin group also had significantly reduced rates of both the first and second outcomes compared to placebo patients (3.7% vs. 4.8% and 4.4% vs. 5.7%, respectively). There was no excess diabetes or cancer associated with the statin, but patients taking it did have more cataract surgeries and muscle symptoms than those on placebo. The study authors noted that the diversity of their trial population (80% nonwhite, about 50% female) makes the findings widely applicable and supports broad use of statins for primary prevention.

Researchers also looked at the effects of the interventions combined, comparing patients who received both active treatments (n=3,180) to those who took both placebos (n=3,168). Compared to placebo patients, the active group had reductions of 33.7 mg/dL in LDL and of 6.2 mm Hg in systolic blood pressure. They also had significantly reduced rates of both composite outcomes compared to the placebo group (3.6% vs. 5.0% and 4.3% vs. 5.9%, respectively). Muscle weakness and dizziness were more common on combined therapy, but the groups had similar rates of drug discontinuation.

The results of this trial support the benefits of statins for primary prevention and a risk-based approach to prescribing, rather than one based on LDL levels, according to an accompanying editorial. The lack of benefit observed from the blood-pressure medications could be due to insufficient dosing or inclusion of lower-risk patients than are typically included in hypertension trials. The finding of benefit only in the highest-pressure subgroup "may help to define the combined threshold of systolic blood pressure (<140 mm Hg) and cardiovascular risk (<5.0%) below which the use of blood-pressure-lowering medications may not be useful in the short term," the editorialists said. The combined analysis showed "no evidence of harm or synergy between the two interventions," they observed.

The U.S. Preventive Services Task Force recommended this week that aspirin be used for primary prevention of cardiovascular disease (CVD) and colorectal cancer.

The new recommendations update the Task Force's 2009 recommendation on aspirin use to prevent CVD events and its 2007 recommendation on aspirin and nonsteroidal anti-inflammatory drugs to prevent colorectal cancer. The Task Force reviewed research published since its last recommendations and also commissioned reviews of the benefits of aspirin for primary prevention of cardiovascular events, total and colorectal cancer incidence and mortality, and bleeding risk. Finally, it commissioned a decision analysis using simulation modeling to assess the expected net benefit of aspirin use across clinically relevant groups defined by their age, sex, and risk for CVD.

The recommendations and supporting evidence were published online April 12 by Annals of Internal Medicine.

Based on its review, the Task Force recommended that low-dose aspirin be initiated for the primary prevention of CVD and colorectal cancer in adults ages 50 to 59 years who have a 10% or greater 10-year CVD risk, are not at increased risk for bleeding, have a life expectancy of at least 10 years, and are willing to take low-dose aspirin daily for at least 10 years (B recommendation; there is high certainty that the net benefit is moderate or there is moderate certainty that the net benefit is moderate to substantial). Ten-year CVD risk was predicted by using a calculator derived from the American College of Cardiology/American Heart Association pooled cohort equations.

In adults ages 60 to 69 years who have a 10% or greater risk CVD risk, the Task Force recommended that the decision to initiate low-dose aspirin for primary prevention of CVD and colorectal cancer should be an individual one. Persons who are not at increased risk for bleeding, have a life expectancy of at least 10 years, and are willing to take a low-dose aspirin daily for at least 10 years are more likely to benefit. Those who place a higher value on potential benefits than potential harms may choose to initiate low-dose aspirin (C recommendation; there is at least moderate certainty that the net benefit is small).

The Task Force noted that current evidence is insufficient to assess the balance of benefits and harms of initiating aspirin use for the primary prevention of CVD and CRC in adults younger than age 50 years or ages 70 years and older (I statements; evidence is lacking, of poor quality, or conflicting, and the balance of benefits and harms cannot be determined).

A 2013 guideline was updated last week, adding 2 new medications as treatment options for stage C heart failure patients with reduced ejection fraction.

The update to the 2013 American College of Cardiology Foundation (ACCF)/American Heart Association (AHA) Guideline for the Management of Heart Failure adds the angiotensin receptor-neprilysin inhibitor (ARNI) valsartan/sacubitril, and the sinoatrial node modulator ivabradine to the list of treatment options for stage C heart failure with reduced ejection fraction.

According to the new recommendations, angiotensin-converting enzyme (ACE) inhibitors, angiotensin II receptor blockers (ARBs), or an ARNI, along with a beta-blocker and an aldosterone antagonist, is the new recommended therapy to reduce morbidity and mortality in patients with chronic symptomatic heart failure with reduced ejection fraction. An ARNI should replace ACE inhibitors or ARBs in stable patients with mild to moderate heart failure on these therapies who have adequate blood pressure and are otherwise tolerating standard therapies well. ARNIs, however, should not be used with an ACE inhibitor and should not be used by patients with a history of angioedema.

Other specific recommendations are as follows:

Although the use of an ARNI in lieu of an ACE inhibitor for heart failure with reduced ejection fraction has been found to be superior, for those patients for whom ARNI is not appropriate, continuing an ACE inhibitor for all classes of heart failure with reduced ejection fraction remains strongly advised.
The use of ARBs to reduce morbidity and mortality is recommended in patients with prior or current symptoms of chronic heart failure with reduced ejection fraction who are intolerant of ACE inhibitors because of cough or angioedema. Head-to-head comparisons of an ARB versus ARNI for heart failure do not exist. For those patients for whom an ACE inhibitor or ARNI is inappropriate, use of an ARB remains advised.
An ARNI should not be administered concomitantly with ACE inhibitors or within 36 hours of the last dose of an ACE inhibitor and should not be administered to patients with a history of angioedema.
Ivabradine can be beneficial to reduce heart failure hospitalizations in patients with symptomatic (New York Heart Association class II-III) stable chronic heart failure with reduced ejection fraction (left ventricular ejection fraction ≤35%) who are receiving guideline-directed evaluation and management, including a beta-blocker at maximum tolerated dose, and who are in sinus rhythm with a heart rate of 70 beats per minute or greater at rest.