Thursday, November 19, 2009

ARBITER 6-HALTS (Big win for Niaspan + Statin Combination)

The American Heart Association’s 2009 Scientific Sessions released the results of the Arterial Biology for the Investigation of the Treatment Effects of Reducing Cholesterol 6: HDL and LDL Treatment Strategies in Atherosclerosis (ARBITER 6-HALTs) trial earlier this week. And now medical office phones are ringing. Patients are asking, should I stay on my current cholesterol lowering medication or should I go on Niaspan?

This study consisted of 363 participants who were on statin (90% were on Lipitor (Atorvastatin) and Zocor (Simvastatin))medications for at least 3 months prior to enrollment into the study. The mean statin dosage was 42 mg. These participants were then divided in half. One group received Ezetimibe (Zetia) 10 mg daily while the other half received Niaspan 2000 mg daily (titrated up over 2 months ).

All participants had the following:

-LDL (bad) Cholesterol less than 100 mg/dL

-HDL (good) Cholesterol less than 50 mg/dL

-Known vascular or coronary disease risk equivalents

Baseline Statistics of both groups:

Mean LDL 84mg/dL and Mean HDL 43mg/dL (Ezetimibe group)

Mean LDL 81mg/dL and Mean HDL 42mg/dL (Niacin group)

After 14 months of treatment – the results:

Mean LDL decreased from 84 mg/dL to 66 mg/dL ; HDL decreased from 43 mg/dL to 40 mg/dL; Triglycerides decreased by 7% in Ezetimibe (Zetia) group.

Mean LDL decreased from 81 mg/dL to 71 mg/dL; HDL increased from 42 mg/dL to 50 mg/dL; Triglycerides decreased by 21%: in the Niacin arm.

Primary Endpoint:

Carotid Intima Media Thickness :

-Niaspan (Niacin) arm Statistically significant regression

-Ezetimibe (Zetia) arm Did not have significant regression but did stop progression

Secondary Endpoints Include:

Coronary Heart Disease (CHD) Death, MI(Heart Attack), Coronary Revascularization (heart stent or balloon to open artery or open heart surgery), Unstable Angina (unstable chest pain)

Ezetimibe (Zetia) group had 9 of the secondary endpoint events out of 165 participants. This is 5.5% in the 14 months of the trial.

Niacin group had 2 of the primary endpoint events out of 169 participants. This is 1.2% in the 14 months of the trial.

Dr. James O’Keefe, Cardiologist at the Mid-America Heart Institute in Kansas City, reports “This is a big win for the Niacin + Statin combination treatment. We have had other randomized studies such as HATS and FATS, both of which are smaller studies like ARBITER 6, which although not powered to show event reduction, did find significantly better cardiovascular outcomes with niacin”.

I was able to attend the meeting at the AHA Session earlier this week. The presenter and lead investigator, Dr. Allen Taylor, from Medstar Research Institute, Washington, DC, reported that in 2008 there were 9 million U.S. patients receiving treatment with Zetia and 2.5 million U.S. patients receiving treatment with Niacin. Although niacin isn’t an easy drug to use, due to its’ flushing side effect we should make strong efforts to help our patients tolerate this medication. Over time the flushing becomes less often, less intense and less in duration. In one Niaspan study, participants who took the medication for 6 months had approximately 2 flushes per month. Dr. James O’Keefe reports, “patients should avoid sustained release over the counter (OTC) niacin products, as they are more hepatotoxic (toxic to liver) than the immediate release (IR) OTC niacin or prescription, Niaspan. “

In summary, if you are taking cholesterol medications we recommend you do not stop your medications without speaking with your health care provider. If you are taking an over the counter niacin product make sure it is an immediate release niacin or we recommend taking prescription form Niaspan-which is often more tolerable. “In our experience, which is supported by this recent study, the combination of niacin with a statin such as Simvastatin (Zocor), Rosuvastatin (Crestor), Atorvastatin (Lipitor) is a great way to go both for buffing the cholesterol numbers and improving cardiovascular prognosis,” Dr. James O’Keefe.

Sunday, November 1, 2009

Coronary Artery Calcium Scan

Coronary artery calcium scan is a simple 15 minute, non-invasive heart test that will assist in determining if one has coronary heart disease (plaque in coronary arteries). Coronary artery calcium (CAC) measures “hard” calcified plaque in heart arteries. This scan does not pick up soft plaque that may have formed in coronary arteries. As coronary plaque builds up, so does the threat of heart events. Arteries become more narrowed and blood has a hard time squeezing through; thus, increasing your risk for severe cardiac events (heart attack).

The Multi-Ethnic of Atherosclerosis (MESA) enrolled 6814 asymptomatic patients, of whom over half, 3563, had zero CAC score at baseline (no hard plaque found in coronary arteries). Study participants who went on to have heart catheterization (invasive procedure that visualizes inside heart arteries) due to symptoms, clinical indications, result of the coronary calcium score, abnormal stress test or preoperative risk stratification included 175 of them. In 96% of these cases, the documented baseline calcium score predicted the actual severity or extent of the obstructed coronary artery disease as found per heart catheterization. But, in the remaining 4% there was significant narrowing of heart arteries from soft plaques found via heart catheterization-despite a zero CAC score.

In symptomatic (chest pain or equivalent) or in suspected coronary artery disease (CAD) patients in the Emergency Room-a zero CAC score has a 96% negative predictive value, meaning that 4% of patients with a zero calcium score will have significant CAD, due to soft plaque. People who present with chest pain or equivalent or who are suspected of having CAD, generally need to have functional imaging (stress MPI, stress ECHO, etc.) rather than a screening calcium score.

In asymptomatic (having no symptoms) patients; but, at risk for heart disease, the CAC scan is an excellent choice. As, the main purpose for CAC scoring should be to detect early subclinical stages (before symptoms) of CAD for which specificity is virtually 100% (people w/o significant CAD will not have calcium in their vessels.)

Dr. Harvey Hecht from Lenox Hill Heart and Vascular Institute in New York, New York was quoted: “A strong argument can now be made for requiring coronary calcium screening before stress testing in asymptomatic patients. Also, less aggressive drug therapy is appropriate for zero-score patients, and at the other end of the spectrum, the presence of coronary calcium identifies the higher risk pool of patients in whom 95% to 96% of the events will emerge; it is this group that will benefit from highly targeted aggressive treatment.”

To wrap this up, if patients present to the emergency room with chest pain symptoms a functional imaging study should be recommended versus a coronary artery calcium scan. In asymptomatic patients screening for early signs of heart disease a coronary artery calcium scan would be an excellent choice. Remember, early detection is the key to preventing heart events.