Threshold for 'High Risk' Reduced in New AHA Guidance on CVD Prevention for Women

The first overhaul in four years of the American Heart Association guidelines on cardiovascular disease prevention in women has lowered the threshold for who is considered "high risk," says the chair of the writing committee, Dr Lori Mosca (Columbia University, New York, NY), who is also lead author of the manuscript, which is published online February 16, 2011 in Circulation [1].
Mosca explained in an interview with heartwire that the new recommendations are based upon an extensive literature search since the last guidance for women, in 2007. "There have been a couple of major changes," she notes. "As well as the lowering of this threshold, we also focus on what can be accomplished in the 'real world' as opposed to what is achievable in clinical trials, and we highlight the fact that women who have had pregnancy complications are at increased risk of CVD."

We highlight the fact that women who have had pregnancy complications are at increased risk of CVD.

In addition, "we've softened the recommendations on certain advice in women," she says, including the use of aspirin in diabetics and the stringency of diabetic control, and introduced new but "soft" guidance on statin use for primary prevention in those with normal cholesterol but raised C-reactive protein (CRP) levels.
"And we have made a call for future research to publish not just efficacy results by gender, but also sex-specific adverse drug reactions [ADRs]," she notes. Having all of this information will help doctors to make better decisions on how best to treat an individual woman, based on a proper assessment of the risk/benefit profile in each case, she says.
Threshold for Treatment Lowered to >10% Risk Over 10 Years
Mosca explains that the previous threshold for what is considered "high risk" among women has been lowered, from a >20% risk of dying from a heart attack in the next 10 years to a >10% risk of dying from any cardiovascular event in the next 10 years.

The ratio of stroke to heart attacks is always higher in women than in men.

"There are two main reasons for this," she says. "First, the primary risk-assessment tools that are used tend to underestimate risk in women, and second, women are more likely than men to experience a stroke vs a heart attack, so we wanted to make sure we encompass that in the risk assessment."
Mosca says that women and even most doctors are "definitely not aware that older women are more likely to have a stroke than a heart attack and that the ratio of stroke to heart attacks is always higher in women than in men."
Pregnancy Complications up CV Risk for Women; Real World Stressed
Mosca continues: "Another important change in terms of risk assessment is that we've now categorized women who have had pregnancy complications as being 'at risk.'
"This is important because often we don't take a pregnancy history. Primary-care physicians in particular, but also cardiologists, should know that preeclampsia or gestational diabetes during pregnancy, and/or birth of a preterm infant or an infant who is small for their gestational age, or bleeding in the third trimester are all associated with increased cardiovascular risk.
"This represents a unique opportunity to identify women at an earlier life stage than they might normally present, so we can institute more aggressive preventive therapy and control of risk factors," she stresses.

We are asking physicians to really look at the balance of benefits and risks in the real-world setting.

The other important change in the guidelines is this "paradigm shift from evidence-based to effectiveness-based," says Mosca. "We recognize that the guidelines themselves are based on science, but we also acknowledge that the results that we see in clinical practice are often less impressive than what we would see in clinical trials, because women are often older and have more comorbidities, so we are asking physicians to really look at the balance of benefits and risks in the real-world setting. There are certain conditions where they might not want to be as aggressive as the guidelines suggest--for example, older frail women who are more likely to have side effects," she notes.
Thresholds Softened for Aspirin and Glycemic Control in Diabetes
The new guidance also includes the softening of a number of prior recommendations. First, the use of aspirin in diabetics, which used to be a class I recommendation, "is now a class IIa," says Mosca, adding, "The data on the benefits of aspirin for diabetics and balancing the risks are not as strong as they are for women with CVD."

The data on the benefits of aspirin for diabetics and balancing the risks are not as strong as they are for women with CVD.

The recommendation for glycemic control in diabetes (HbA1c <7%) is also softened, she says, because again, "there may be adverse effects of too aggressive control in some women."
And although there has been no change on the recommendations for the use of aspirin for primary prevention in women generally, "most people don't realize we don't strongly recommend it for women under 65," Mosca says.
Another new but "fairly soft recommendation" is for the use of statins in primary prevention in women without raised cholesterol but who have an elevated CRP level, the JUPITER-type population, she says.
"The rationale for this is that the absolute benefit is very small, even though the proportional risk reduction is very high. We want doctors to recognize that the long-term side effects and cost [of statins] might outweigh the benefits. We give it a softer recommendation than we might have because of our shift toward 'real-world' issues."
And finally, she says, "We really make a call to action that future research should publish both efficacy and ADRs by gender. While doctors are getting better at publishing sex-specific efficacy analyses, it's very rare to see side-effect data by gender, and that's important," she concludes.
Mosca declares she has no conflicts of interest; disclosures for the coauthors are listed in the paper.