AMSTERDAM – Sixty percent of all myocardial infarctions and cardiovascular deaths in a large population of stable outpatients with coronary artery disease occurred in patients with neither anginal symptoms in daily life nor evidence of silent myocardial ischemia.
"This emphasizes the need to enforce secondary prevention measures, even in stable asymptomatic patients, Dr. Phillipe G. Steg observed at the annual congress of the European Society of Cardiology.
The risk of these adverse events was significantly greater in patients with stable coronary artery disease (CAD) who had angina than in those with neither angina nor silent myocardial ischemia, and higher still in those with both angina and silent ischemia. But in patients with silent ischemia and no angina, the risk of adverse clinical outcomes wasn’t significantly different than in patients with neither angina nor ischemia, added Dr. Steg, professor of cardiology at the University of Paris.
He presented an analysis from the CLARIFY registry, a prospective registry including 32,396 patients with stable CAD enrolled during 2009-2010 in 45 countries and followed up for 2 years. Participants had to have a baseline history of MI, chest pain with evidence of myocardial ischemia, evidence of CAD on coronary angiography, or prior PCI or CABG surgery.
For this analysis, Dr. Steg focused on the 20,402 CLARIFY participants who underwent noninvasive testing for myocardial ischemia within 1 year prior to enrollment and didn’t undergo revascularization as a result of the findings. These patients fell into four categories: 65% had neither angina nor myocardial ischemia at baseline, 9% had angina without ischemia, 15% had ischemia and no angina, and 11% had both angina and ischemia.
The absolute risk of the primary composite endpoint – cardiovascular death or nonfatal MI – was just under 4% in 2 years of follow-up in the patients with both angina and ischemia.
"I think that low rate corresponds to the modern environment of a well-treated patient population. Even though this was a global registry, patients were remarkably well treated, with a high rate of use of antiplatelet agents, lipid-lowering therapies, ACE inhibitors, and beta-blockers. I think it’s striking that two-thirds of the population had neither angina nor ischemia," he added.
In a multivariate analysis adjusted for demographics, smoking status, dyslipidemia, and diabetes, patients with angina but not silent ischemia had a statistically significant 46% greater risk of cardiovascular death or nonfatal MI than did those with neither angina nor ischemia. Patients with both angina and ischemia had a 76% greater risk than did the comparison group.
For the secondary composite endpoint consisting of cardiovascular death, MI, stroke, or revascularization, the angina-only group was at 38% increased risk and the angina-plus-ischemia group had a 58% greater risk than did patients with neither angina nor ischemia.
Importantly, major bleeding was not linked to the presence of ischemia, angina, or both.
The CLARIFY registry was supported by Servier. Dr. Steg has received research funding from and served as a consultant to the company. He has also consulted for a dozen other pharmaceutical or medical device companies.