Q / Does niacin decrease cardiovascular morbidity and mortality in CVD patients?
A / NO. Niacin doesn't reduce cardio-vascular disease (CVD) morbidity or mortality in patients with established disease (strength of recommendation [SOR]: A, meta-analyses of randomized controlled trials [RCTs] and subsequent large RCTs).
Niacin may be considered as mono therapy for patients intolerant of statins (SOR: B, one well-done RCT).
Before the statin era, the Coronary Drug Project RCT (8341 patients) showed that niacin monotherapy in patients with definite electrocardiographic evidence of previous myocardial infarction (MI) reduced nonfatal MI to 8.9% compared with 12.2% for placebo (P=.002). (1) (See TABLE. (1-4)) It also decreased long-term mortality by 11% compared with placebo (P=.0004). (5)
Adverse effects such as flushing, hyperglycemia, gastrointestinal disturbance, and elevated liver enzymes interfered with adherence to niacin treatment (66.3% of patients were adherent to treatment with niacin vs 77.8% for placebo). The study was limited by the fact that flushing essentially unblinded participants and physicians.
But adding niacin to a statin has no effect
A 2014 meta-analysis driven by the power of the large HPS2-Thrive study evaluated data from 35,301 patients primarily in secondary prevention trials. (2,3) It found that adding niacin to statins had no effect on all-cause mortality, coronary heart disease mortality, nonfatal MI, or stroke. The subset of 6 trials (N=4991) assessing niacin monotherapy did show a reduction in cardiovascular events (odds ratio [OR]=0.62; confidence interval [CI], 0.54-0.82), whereas the 5 studies (30,310 patients) involving niacin with a statin demonstrated no effect (OR=0.94; CI, 0.83-1.06).
No benefit from niacin/statin therapy despite an improved lipid profile A 2011 RCT included 3414 patients with coronary heart disease on simvastatin who were randomized to niacin or placebo. (4) All patients received simvastatin 40 to 80 mg [+ or -] ezetimibe 10 mg/d to achieve low-density lipoprotein (LDL) cholesterol levels of 40 to 80 mg/dL.
At 3 years, no benefit was seen in the composite CVD primary endpoint (hazard ratio=1.02; 95% CI, 0.87-1.21; P=.79) even though the niacin group had significantly increased median high-density lipoprotein (HDL) cholesterol compared with placebo and lower triglycerides and LDL cholesterol compared with baseline.
A nonsignificant trend toward increased stroke in the niacin group compared with placebo led to early termination of the study. However, multivariate analysis showed independent associations between ischemic stroke risk and age older than 65 years, history of stroke/transient ischemic attack/carotid artery disease, and elevated baseline cholesterol. (6)
Niacin combined with a statin increases the risk of adverse events
The largest RCT in the 2014 meta-analysis (HPS2-Thrive) evaluated 25,673 patients with established CVD receiving cholesterol-lowering therapy with simvastatin [+ or -] ezetimibe who were randomized to niacin or placebo for a median follow-up period of 3.9 years. (3) A pre-randomization run-in phase established effective cholesterol-lowering therapy with simvastatin [+ or -] ezetimibe.
Niacin didn't reduce the incidence of major vascular events even though, once again, it decreased LDL and increased HDL more than placebo. Niacin increased the risk of serious adverse events 56% vs 53% (risk ratio [RR]=6; 95% CI, 3-8; number needed to harm [NNH]=35; 95% CI, 25-60), such as new onset diabetes (5.7% vs 4.3%; P<.001; NNH=71) and gastrointestinal bleeding/ulceration and other gastrointestinal disorders (4.8% vs 3.8%; Pc.001; NNH=100).
A subsequent 2014 study examined the adverse events recorded in the AIM-HIGH4 study and found that niacin caused more gastrointestinal disorders (7.4% vs 5.5%; P=.02; NNH=53) and infections and infestations (8.1% vs 5.8%; P=.008; NNH=43) than placebo. (7) The overall observed rate of serious hemorrhagic adverse events was low, however, showing no significant difference between the 2 groups (3.4% vs 2.9%; P=.36).
As of November 2013, the Institute for Clinical Systems Improvement recommends against using niacin in combination with statins because of the increased risk of adverse events without a reduction in CVD outcomes. Niacin may be considered as monotherapy in patients who can't tolerate statins or fibrates based on results of the Coronary Drug Project and other studies completed before the era of widespread statin use. (8)
Similarly, American College of Cardiology/American Heart Association guidelines state that patients who are completely stat-in intolerant may use nonstatin cholesterol-lowering drugs, including niacin, that have been shown to reduce CVD events in RCTs if the CVD risk-reduction benefits outweigh the potential for adverse effects. (9)
Peter Lazzopina, MD; Anne Mounsey, MD University of North Carolina Family Medicine Residency, Chapel Hill
Lara Handler, MSLS University of North Carolina, Chapel Hill
DEPUTY EDITOR Rick Guthmann, MD, MPH
Advocate Illinois Masonic Family Medicine Residency, Chicago
(1.) Coronary Drug Project Research Group. Colofibrate and niacin in coronary heart disease. JAMA. 1975;231:360-81.
(2.) Keene D, Price C, Shun-Shin MJ, et al. Effect on cardiovascular risk of high density lipoprotein targeted drug treatments niacin, fibrates, and CETP inhibitors: meta-analysis of randomised controlled trials including 117,411 patients. BMJ. 2014;349: g4379.
(3.) HPS2-Thrive Collaborative Group. Effects of extended-release niacin with laropiprant in high-risk patients. N Engl J Med. 2014;371:203-212.
(4.) AIM-HIGH Investigators. Niacin in patients with low HDL cholesterol levels receiving intensive statin therapy. N Engl J Med. 2011;365:2255-2267.
(5.) Canner PL, Berge KG, Wender NK, et al. Fifteen-year mortality in Coronary Drug Project patients: long-term benefit with niacin. J Am Coll Cardiol. 1986;8:1245-1255.
(6.) AIM-HIGH Investigators. Extended-release niacin therapy and risk of ischemic stroke in patients with cardiovascular disease: the Atherothrombosis Intervention in Metabolic Syndrome with low HDL/High Triglycerides: Impact on Global Health Outcome (AIM-HIGH) trial. Stroke. 2013;44:2688-2693.
(7.) AIM-HIGH Investigators. Safety profile of extended-release niacin in the AIM-HIGH trial. N Engl J Med. 2014;371:288-290.
(8.) Institute for Clinical Systems Improvement. Guideline summary: Lipid management in adults. National Guideline Clearinghouse. Rockville, MD: Agency for Healthcare Research and Quality. Available at: http://www.guideline.gov. Accessed July 20, 2015.
(9.) Stone NJ, Robinson J, Lichtenstein AH, et al. 2013 ACC/AHA guideline on the treatment of blood cholesterol to reduce atherosclerotic cardiovascular risk in adults: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation. 2014;25 (suppl 2):S1-S45.
TABLE Niacin for CVD: What the studies show Study type Population Meta- 35,301 patients in secondary analysis (2) prevention trials (11 studies) RCT 25,673 patients ages HPS2-Thrive 50-80 yrs with Collaborative established CVD Group (3) RCT 3414 patients ages AIM-HIGH (4) [greater than or equal to] 45 yrs with established CVD (85.2% male, 92.2% white) RCT 8341 males ages 30-64 yrs Coronary Drug with definite EKG evidence Project (1) of MI Study type Intervention Comparison Meta- Niacin alone or in Placebo or analysis (2) combination with other alternative (11 studies) cholesterol-lowering cholesterol-lowering agents agent RCT Niacin/laropiprant Placebo HPS2-Thrive 2 g/40 mg daily, in Collaborative combination with Group (3) statin [+ or -] ezetimibe; median follow-up 3.9 yrs RCT All patients were Placebo AIM-HIGH (4) treated with statins and then randomized to niacin 1.5-2 g/d for 36 mos or placebo RCT Niacin 3 g/d Placebo Coronary Drug Project (1) Study type Outcome Comments Meta- No effect on: analysis (2) (11 studies) 1. All-cause mortality (OR=1.02; 95% CI, 0.92-1.15; P=.59) 2. Coronary heart disease mortality (OR=0.93; 95% CI, 0.76-1.12; P=.44) 3. Nonfatal myocardial infarction (OR=0.85; 95% CI, 0.72-1.01; P=0.07) 4. Stroke (OR=0.96; 95% CI, 0.75-1.22; P=.72) RCT No effect on: Laropiprant, HPS2-Thrive used to suppress Collaborative Major vascular events flushing, may be a Group (3) (13.2% vs 13.7%; rate contributing ratio=0.96; 95% CI, variable to the 0.90-1.03; P=.29) adverse effects seen with this study * Major coronary events (rate ratio=0.96; 95% CI, 0.87-1.07; P=.51) * Stroke (rate ratio=1; 95% CI, 0.88-1.13; P=.56) RCT No effect on major Study was AIM-HIGH (4) CVD events: discontinued early 16.4% vs 16.2% (HR=1.02; 95% because of a trend CI, 0.87-1.21; P=.79) toward increased ischemic stroke (HR=1.61; 95% CI, 0.89-2.91; P=.11) RCT Reduction in nonfatal MI Coronary Drug (8.9% vs 12.2%; P=.002) Project (1) CI, confidence interval; CVD, coronary vascular disease; EKG, electrocardiogram; HR, hazard ratio; MI, myocardial infarction; OR, odds ratio.
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|Title Annotation:||CLINICAL INQUIRIES; cardiovascular diseases|
|Author:||Lazzopina, Peter; Mounsey, Anne; Handler, Lara|
|Publication:||Journal of Family Practice|
|Date:||May 1, 2018|
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