Chapel Hill, NC - The American Heart Association (AHA) and the American College of Cardiology (ACC) have updated their guidelines for the secondary prevention of coronary and other atherosclerotic vascular diseases, to incorporate emerging evidence from clinical trials [1].

The update—the first since 2001—appears in Circulation May 15, 2006. Lead author Dr Sid Smith (University of North Carolina, Chapel Hill), who is the chair of the AHA/ACC Task Force that overseas all 17 sets of guidelines, outlined the main changes for heartwire.

He also explained that a new update process has been instituted, so that late-breaking clinical trials and new study results from all the major cardiology meetings each year are monitored to see whether any changes in guidelines are required.

For the first time, influenza vaccination is now recommended for all patients with chronic cardiovascular disease, Smith said. Dr Mohammad Madjid (University of Texas Health Sciences Center, Houston) told heartwire that it is vital that cardiologists get the message that immunization against flu is important in patients with cardiovascular disease. One study, FLUVACS, showed a 50% reduction in cardiovascular deaths in those patients vaccinated against flu. Madjid said his team has an active research program on influenza and heart disease and has two major related papers currently under review.

The second change echoes the NCEP ATP III guidelines of 2004, "confirming the benefits of intensive lowering of cholesterol and indicating that for all patients with coronary artery disease [CAD] and other forms of vascular disease, LDL cholesterol should be lowered to under 100 mg/dL," Smith noted.

In addition, it is also deemed "reasonable" for those with chronic heart disease to be treated until their LDL is below 70 mg/dL, he noted. He explained that the use of the word "reasonable" reflects a class II recommendation, compared with the use of the word "should," which represents a class I recommendation. But for those with other forms of vascular disease (noncoronary), "we are still waiting for the evidence that lowering LDL below 70 will be beneficial," Smith notes.

The next modification to the guidelines is an emphasis on reducing waist circumference, to less than 35 inches for women and less than 40 inches for men, and encouraging physical activity for 30 to 60 minutes seven days a week (minimum five days). Smith said the committee has purposely chosen the word "activity" rather than "exercise" to communicate that "all you have to do is get off your chair, get up, and do some sort of physical activity."

For smoking, the recommendations are to pursue smoking cessation for the individual and for everyone, where possible, to avoid passive smoking. Smith commented on legislation being enacted around the world to ban smoking in public places: "It's just wonderful to see these changes occurring."

Other changes include the recommendation to expand the use of ACE inhibitors to include congestive heart failure patients with left ventricular ejection fractions of 40% or less. Also, it is "reasonable" to use them in patients with CHD, Smith says, although "their benefits in patients at lower risk and on multiple therapies following revascularization is less well-established," he notes. This statement reflects the confusion that followed the results of the PEACE trial, which was at odds with earlier data from HOPE and EUROPA, Smith explained, adding that decisions on the use of ACE inhibitors in such patients must be made on an individual basis.

Meanwhile, the dose of aspirin recommended for chronic therapy in patients with established coronary or atherosclerotic vascular disease has been reduced to between 75 and 162 mg/day, down from the previous guide of 75 to 325 mg/ day. "This reflects the fact that the lower dose of aspirin reduces cardiovascular events by the same magnitude as the higher dose but with less bleeding," Smith commented.

The only exception to this is in patients undergoing coronary artery bypass grafting. "We had a very interesting discussion about this on the committee," Smith revealed. He said that the cardiac surgeons had explained that there were no trial data with lower doses of aspirin following CABG, "and so the feeling was that, until we have trials in CABG showing the effects of 75 to 162 mg/day of aspirin, we can't take the chance that this lower dose would keep the grafts open."

Finally, changes to the recommendations for aspirin and clopidogrel following percutaneous coronary intervention (PCI) reflect new PCI guidelines issued just last year, Smith explained. For those receiving a bare-metal stent, aspirin 325 mg/day should be given for a month; for those receiving a sirolimus-eluting (Cypher) stent, this should be three months; and for the paclitaxel-eluting (Taxus) stent, aspirin should be given for six months.

The much-debated question of how long to administer clopidogrel following drug-eluting-stent placement and what to do in the event of other scheduled surgery in patients with drug-eluting stents on clopidogrel was not addressed, Smith admitted.