Gender Disparity in CHD: Bias, Biology, or Both?


FEATURE STORY

In another lecture during the annual convention of the Philippine Heart Association (PHA), Dr. Nanette Wenger, emeritus professor of Medicine (Cardiology) at the Emory University School of Medicine and a founding consultant of the Emory Women’s Heart Center, dissects the gender differences in coronary heart disease

By Lorielle Marie Es Galvez, MD
Cardinal Santos Medical Center


Coronary heart disease (CHD) remains to be the leading cause of death worldwide and there seems to be a gender disparity in the numbers. But is this disparity a form of bias or a case of biology? Or perhaps both?

Women’s heart health specialist Dr. Nanette Wenger tried to differentiate the gender health disparity in cardiovascular terms.

Disparities, she said, is the difference between groups based on gender, race, ethnicity, socioeconomic status, education, income, environmental factors, health care system experience, access to and utilization of quality of care.

Prof. Wenger noted that CHD risk is 25 percent greater in women than in men who are smokers. Similarly in diabetes and metabolic syndrome, CHD risk is higher in women than their male counterparts.

Further, she explained that angina is a predominant initial and subsequent presentation of CHD in women with stable ischemic heart disease. However, women present with atypical symptoms such as sudden shortness of breath, unusual fatigue, anxiety or abdominal discomfort.

Prof. Wenger identified these women to be older, hypertensive, and/or diabetic. She further presented studies that show comparable prevalence of stable angina in women and in men. However, physicians may be underdiagnosing angina in women if they are not seeing comparable number of women and men in their clinics, the lady doctor warned.

She went on to cite the Euro Heart survey of stable angina that reported after a period of follow up, women had a double occurrence of death and non-fatal heart attacks even when adjusted for age, co-morbidities, pharmacotherapy and revascularization.

The Women’s Ischemic Syndrome Evaluation (WISE) study included women with documented myocardial ischemia and chest pain. One half of the population had no flow-limiting coronary obstructive disease at angiography, who experienced persistent chest pain and subsequent significant occurrence of coronary events. She said this implies that even in the absence of obstructive coronary disease, persistent chest pains predict cardiovascular events, hence the main goal should be directed to alleviating chest pain by all means available.

Women with stable ischemic heart disease tend to have more frequent hospitalizations and less ability to perform activities of daily living, Prof. Wenger expounded. Their disability correlates poorly with obstructive CHD but with doubled morbidity and mortality.

Moreover, women have less severe obstructive disease characterized as having only single significantly affected vessel but have more complex pathophysiology than men. Women have more reported cases of microvascular disease, endothelial dysfunction and high atherosclerotic burden.

With these facts, Prof. Wenger summarized that chest pain in the absence of obstructive CHD is more common in women. Even in the absence of obstructive CHD, there is an adverse outcome of unexplained mechanism, but certainly, the underlying feature is myocardial ischemia. This microvascular or non-obstructive CHD is detrimental, but how to best recognize it and satisfactorily treat it remains to be determined.

Citing another investigation, Prof. Wenger reported that women with non-STelevation myocardial infarction (NSTEMI) acute coronary syndrome (ACS) are a highrisk population characterized by a higher incidence of death, myocardial infarction, heart failure, stroke and transfusion.

Gender Disparity in CHD Bias, Biology, or Both 2

The CRUSADE trial is a study in patients with NSTEMI, which has a good representation of women. However, they were less likely to receive acute therapy with heparin, angiotensin converting enzyme inhibitor (ACEI), GP IIb/IIIa inhibitors; and aspirin, ACEI, statin upon discharge.

In patients with established MI, women had a doubled mortality especially those women <age 50. Psychological factors like depression are contributory, Prof. Wenger said.

Women have higher recurrence of rate of MI and subsequent heart failure, particularly Heart Failure with preserved Ejection Fraction (HFpEF).

Further, Prof. Wenger culled data from registries noting that women with NSTEMI have higher mortality compared to men. Interventions that improve survival such as early aspirin/beta-blocker, reperfusion therapy and timely perfusion were not given in a timely manner due to less recognition of MI until after initial 24 hours.

She said there is a need to identify such delays in treating women in order to decrease gender disparities in care, hence improved outcome.

On secondary prevention of CHD, more women are obese, diabetic, and with elevated low-density lipoprotein cholesterol (LDL-C), blood pressure (BP), and glycosylated haemoglobin (HbA1c) targets are less likely to be achieved in women. From the trials on percutaneous coronary intervention (PCI), PCI had comparable outcomes in women and men but drug-eluting stents (DES) selectively benefitted women.

Despite more risk factors and older age in women, women have more likely to have single vessel disease, though more complications are expected from them, Prof. Wenger reported.

With these new information in mind, Prof. Wenger left it to her audience to decide whether gender disparity in CHD is due to bias, biology, or both.

“Chest pain in the absence of obstructive CHD is more common in women; there is an adverse outcome of unexplained mechanism, but certainly, the underlying feature is myocardial ischemia”

June 2017 Health and Lifestyle

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