By William Abraham, MD
This year’s annual meeting of the American College of Cardiology provided some practical insights into medical treatments and the impact of lifestyle on cardiovascular outcomes. In this post, I cover the results of two important studies presented for the very first time at this meeting of 13,000 cardiovascular team members.
The first study, called the POISE-2 (PeriOperative ISchemic Evaluation-2) trial, concludes that both aspirin and the blood pressure lowering drug, clonidine, are dangerous when given to patients around the time of non-cardiac surgery.
The second report, from the ongoing Women’s Health Initiative study, suggests that women who consume as little as two diet sodas daily are at increased risk for serious cardiovascular events, like heart attacks and strokes.
Lessons from the POISE-2 Trial on Clonidine, Aspirin and Your Heart
Let’s start with the study of aspirin and clonidine in non-cardiac surgery. Major heart problems, such as heart attacks and strokes, complicate surgeries that do not involve the heart. The POISE-2 trial evaluated the impact of aspirin alone, clonidine alone, or the combination of aspirin and clonidine. It compared them to placebo, following the 30-day risk of death from any cause or nonfatal heart attack in patients with, or at risk of, hardening of the arteries (known as atherosclerotic disease) undergoing non-cardiac surgery. Just more than 10,000 men (52 percent) and women (48 percent) with an average age of 68 years were enrolled at 135 centers in 23 countries.
Aspirin was of no benefit on the rate of death or nonfatal heart attack. Aspirin increased the risk of bleeding. Major bleeding was 23 percent more frequent in the aspirin group, compared to placebo (4.6 percent vs. 3.8 percent, respectively). The use of clonidine in some patients did not affect the results of the aspirin analysis.
Bottom line: if you are not taking aspirin prior to non-cardiac surgery, don’t start it. If you are taking aspirin, stop it at least three days prior to surgery and don’t restart it until at least a week after surgery. For specific recommendations, consult your physician.
Clonidine was of no benefit on the rate of death or nonfatal heart attack and increased the risk of low blood pressure (hypotension) and slow heart rate (bradycardia). Clinically important hypotension was 32 percent more frequent in the clonidine group, compared to placebo (47.6 percent vs. 37.1 percent, respectively). Clinically important bradycardia was 49 percent more frequent in the clonidine group, compared to placebo (12 percent vs. 8.1 percent, respectively). There was also an increased risk of nonfatal cardiac arrest in the clonidine group, compared to placebo, but the overall rate of this event was very low in both groups (0.3 percent vs. 0.1 percent, respectively).
Bottom line: clonidine should not be routinely used in the setting of major non-cardiac surgeries.