Dear Dr. Roach: I’m a 78-year-old man with a stent and a blockage in one of the arteries to my heart. I am on a low-fat diet and take ramipril for cholesterol. My levels are very good (total cholesterol is 120 mg/dL, HDL is 44 mg/dL, and LDL is 60 mg/dL). However, my C-reactive protein (CRP) level is high, at 2.8 mg/dL.
My question involves the use of hs-CRP monitoring of inflammation, along with the subsequent long-term use of 0.5 mg of colchicine (where appropriate), to reduce the risk of future atherothrombosis events. The U.S. Food and Drug Administration approved this treatment to lower the risk of future cardiac events by a reported 31%. According to recent American Heart Association (AHA) guidelines, my hs-CRP places me in the upper range of the “moderate risk” cohort, despite statin therapy.
I had a conversation with the cardiologist who has been treating me for many years. I respect his expertise, but he seemed unfamiliar with the guidelines. He felt the studies that led to these guidelines were inadequate, and more extensive, long-term studies were needed before any changes in treatment would be considered. He was adamant that he would not prescribe 0.5 mg of colchicine to anyone in his practice and that he was unaware of any colleagues who would do so.
I have been unable to locate any health-care professional who has experience treating patients under the Centers for Disease Control/AHA guidelines for hs-CRP monitoring, as well as the CDC-approved colchicine. As I read the guidelines, I found that I am at a moderate to high risk for a future cardiac event. Adding 0.5 mg of colchicine to my medication regimen could potentially result in a substantial lowering of this risk.
But how serious are the risks of colchicine (whether it’s diarrhea or other side effects), and do these risks outweigh the possible benefits?
R.G.
I looked carefully at the trials supporting the use of low-dose colchicine (an old drug normally used for gout). Eighty-five per cent of the study participants were men. The most important result is a lowered risk of heart attacks, strokes, and the need for a surgery or stent. Colchicine did not reduce the overall risk of death or the risk of death due to heart disease.
The magnitude of the benefit was modest; 3.6% of people in the placebo group had one of the above outcomes, while 2.5% in the colchicine group only met one of the criteria. This is a 31% relative decrease, but it’s also a 1.1% absolute decrease, meaning about 90 people must be treated for five years to prevent one bad event. Hs-CRP was not considered in the most recent study, and people with a high hs-CRP are more likely to receive benefits.
The published downsides were small, but they looked for severe adverse events like hospitalization. Moreover, 15% of those who started taking the medication never actually started the study, as they couldn’t tolerate the medicine, most commonly from gastrointestinal side effects like nausea or diarrhea. Muscle aches were common in both the colchicine and placebo group. The drug should not be used in people with kidney or liver disease.
I asked some cardiology colleagues and did not find a lot of enthusiasm for colchicine. The modest benefit, the potential for side effects, and a degree of fatigue for newer drugs were all reasons they gave. Personally, I think it’s worth a discussion in people with known blockages, especially if they have a high hs-CRP.
Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to [email protected]
