Major Finding: Four-year follow-up of a large, atherothrombotic disease database found four factors that strongly determine risk for new ischemic events: polyvascular disease, ischemic event within the past year, any history of an ischemic event, and current treatment for diabetes.
Data Source: The REACH registry, which enrolled in 44 countries and tracked ischemic events in 45,227 patients with established atherothrombotic disease or multiple risk factors for 4 years during 2003-2008.
Disclosures: REACH is partially sponsored by Sanofi-Aventis and Bristol-Myers Squibb. Dr. Bhatt reported receiving research grants from AstraZeneca, Bristol-Myers Squibb, Eisai, Ethicon, Heartscape, Sanofi-Aventis, and the Medicines Company.
STOCKHOLM — Four simple clinical conditions play the biggest role in risk-stratifying outpatients with stable atherothrombotic disease, based on a 45,000-patient, international registry followed for 4 years.
Polyvascular disease heads the list of four factors, followed by history of an ischemic event within the past year, history of an ischemic event at any time, and diabetes, Dr. Deepak L. Bhatt said at the congress. The registry results notably showed polyvascular disease to pose the strongest risk for a subsequent ischemic event, and placed diabetes below the risk from a prior ischemic event, a finding that further dislodges diabetes from its perch as a myocardial infarction risk equivalent, said Dr. Bhatt, chief of cardiology at the VA Boston Healthcare System.
“It's an important point, but unfortunately the myth lingers on” that diabetes is a myocardial infarction risk equivalent, he said. It is a myth Dr. Bhatt dates to studies reported more than a decade ago.
In the more contemporary database studied by Dr. Bhatt and his associates, with patients followed from 2003 to 2008, patients with diabetes may have been better managed. “It's not that diabetes is not an important risk factor, but a prior ischemic event trumps diabetes,” he said in an interview. The new analysis shows “only a myocardial infarction is a myocardial infarction risk equivalent.”
The 4-year results from the Reduction of Atherothrombosis for Continued Health (REACH) registry also added new evidence on the role of polyvascular disease, the study's “most potent predictor of future ischemic events. REACH is the largest and longest registry” to show a strong polyvascular effect, a risk factor that until now has been underappreciated, Dr. Bhatt said.
“A patient with angina and claudication [ischemic disease in two vascular beds] may look stable, but the message from these data is that these patients are at exceedingly high risk for something bad happening over the next 4 years,” and so need even tighter medical control of lipids, blood pressure, and other treatable risks.
Dr. Bhatt and his associates are in the final stages of refining a secondary-prevention risk model, a formula to mathematically stratify patients' risk based on the new REACH analysis. While the model isn't ready for release yet, it is based on the four major risk factors he reported. Until now, “there really hasn't been any major attempt to risk-stratify secondary prevention patients, in part because many physicians seem to feel that the risk faced by all secondary-prevention patients is the same. “These data show that's not true. There is a wide range of risk in this population, and risk stratification is called for.” Higher-risk patients could receive, for example, intensive case management by a nurse, or may be candidates for expensive, new antiatherosclerotic, anti-inflammatory, or antithrombotic therapies, with some nearing the market. “I don't think we can afford to use [new, expensive treatments] on all patients. This analysis helps identify patients at the highest risk” who make good candidates for efficacy studies.
The REACH registry initially enrolled more than 68,000 people at 5,587 centers in 44 countries during 2003 and 2004. Reports on the baseline and 1-year follow-up data appeared several years ago (JAMA 2006;295:180-9, and JAMA 2007;297:1197-206). The new analysis used data collected after 4 years' follow-up from 45,227 of the participants.
The database included 21,890 patients with a prior ischemic event (myocardial infarction or stroke) at the time of enrollment into the registry. Another 15,264 patients entered based on having symptomatic, stable atherosclerosis but no event history. The final 8,073 participants had no documented disease but at least three risk factors off this list: current treatment for diabetes, diabetic retinopathy, an ankle-brachial index below 0.9, asymptomatic carotid stenosis with at least 70% occlusion, carotid intima media thickness at least twice that at adjacent sites, systolic blood pressure of at least 150 mm Hg, hypercholesterolemia, current smoker, age 65 or older in men, and age 70 or older in women.