CHICAGO – Men and women may not really be all that different when it comes to mild coronary artery disease.
A prospective, multinational registry analysis found that 1.2% of women and 1.1% of men with mild, nonobstructive coronary artery disease on coronary CT angiography experience a major adverse cardiovascular event, either heart attack or death, each year.
Patrice Wendling/Frontline Medical News
Dr. Jonathon Leipsic
For those free of coronary artery disease (CAD), the event rate was 0.3% for both sexes, Dr. Jonathon A. Leipsic reported at the annual meeting of the Radiological Society of North America.
Women’s heart disease is typically viewed as different from men’s heart disease, in part because of women’s unique presenting symptomatology. Studies such as the Women’s Health Initiative have also reported that women with nonspecific or atypical chest pain have a twofold greater risk for nonfatal MI.
Importantly, all prior data has been reliant on invasive coronary angiography for anatomical coronary assessment, observed Dr. Leipsic, codirector of advanced cardiac imaging, Providence Health Care Heart Center at St. Paul’s Hospital, Vancouver, B.C.
The current analysis, however, used data from the prospective CONFIRM (Coronary CT Angiography Evaluation for Clinical Outcomes: An International Multicenter) registry, which tracks roughly 28,000 individuals in North America, Europe, and Asia who have undergone coronary CT angiography.
The results represent a major shift in thinking, Dr. Leipsic said in an interview.
"What we realize is that CT identifies mild disease in the wall in a way that the invasive angiogram does not," he said. "So suddenly, when you say you have a normal invasive angiogram, there may still be mild disease in the arteries, whereas when you have a normal CT in a woman, our data would suggest that those women do very well, even if they have symptoms."
Dr. Leipsic and his associates identified 18,158 patients in the CONFIRM registry with no disease or mild CAD with less than 50% stenosis. Propensity matching for risk factors, chest pain, and extent of disease left 11,462 patients.
Their average age was 55 years, 34% were asymptomatic, 45% had hypertension, 12% were diabetic, and 18% were current smokers.
Of these, 37 had an MI; 120 died; and 7 had an MI and died (1.4%).
The annual major adverse cardiovascular event (MACE) rate was 0.6% overall, and was significantly different between patients with a normal CT and those with nonobstructive disease (0.3% vs. 1.1%), Dr. Leipsic said.
"This mild disease we see on CT is not just incidental," he said during a press briefing at the meeting. "It actually identifies patients who are at increased risk of having a heart attack and dying, with an increased risk of 1.84 for the overall cohort (P = .001)."
Notably, 3-year MACE-free survival was similar among men and women without coronary plaque on CT as well as those with non-obstructive disease.
Dr. Leipsic commented that detractors of the data have argued that the analysis failed to focus on women at the greatest risk – those with atypical symptoms. A further sub-analysis, however, based on the presence or absence of symptoms and the type of symptoms (nonanginal chest pain, atypical angina, and typical angina), once again "found that men and women behave similarly," he said.
Event rates were lower in men and women with normal CT scans and elevated in both sexes in the setting of nonobstructive disease, "regardless of the nature of chest pain and even in the absence of chest pain," he noted.
Press briefing moderator Dr. Candice Johnstone of the Medical College of Wisconsin, Milwaukee, said in an interview, "Observational studies have limits, but at the same time, I think it may be a paradigm shift, in that it may be a new tool in our toolbox for people at lower risk of heart disease to avoid an invasive procedure."
Dr. Leipsic reported financial relationships with several entities including GE Healthcare, HeartFlow, Edwards LifeSciences, and TC3.