Aortic diastolic pressure decay explains sex-related differences in the subendocardial viability ratio: the Wakuya study

Abstract

Objective:Coronary heart disease is the leading cause of mortality in women. Despite a higher risk of heart failure after the first myocardial infarction in women compared with men, the sex-specific mechanisms are unknown. We hypothesized that myocardial ischemia is attributable to sex-related diastolic alterations in the central hemodynamics.Methods:We investigated the subendocardial viability ratio (myocardial oxygen supply/demand) and aortic diastolic pressure decay index in 962 apparently healthy adults (mean age, 56 ± 10 years). Using noninvasive applanation tonometry, the subendocardial viability ratio, aortic diastolic pressure decay index, and aortic augmentation index were estimated in all participants. The aortic diastolic pressure decay index was quantified by fitting an exponential curve: P(t) = P0e−λt (λ, decay index; P0, end-systolic pressure; t, time from end-systole).Results:Women showed a significantly higher aortic diastolic pressure decay index, even after adjusting for age, hypercholesterolemia, and diabetes, and a significantly lower subendocardial viability ratio than men (P < 0.001). Analysis demonstrated a mediating effect of the aortic decay index on the sex-related differences in the subendocardial viability ratio (71%), despite different effects of the augmentation index (5%).Conclusion:These results suggest that the predisposition of women to coronary heart disease is more likely attributable to impaired myocardial perfusion caused by accelerated aortic diastolic pressure decay, rather than increased myocardial load due to augmented aortic systolic pressure.

Reply to ‘Known unknowns of sex differences in cardiovascular physiology – can arterial waveforms provide answers?’

“…We thank Picone et al [1] for their interest in our recent article [2]. In our recent article, we demonstrated that aortic diastolic pressure decay is accelerated in women and mediates the relationship between sex and subendocardial viability ratio (SEVR).…”

Sex differences in pressure and flow waveform physiology across the life course

“…Other conventional pulse wave analysis variables that exhibit sex differences include sub-endocardial viability ratio and aortic diastolic decay index [86]. Sub-endocardial viability ratio provides an estimate of the ratio between myocardial oxygen supply and demand [87] and, when derived from carotid or estimated aortic pressure waveforms, is lower in women compared with men across different ages [88,89].…”

Known unknowns of sex differences in cardiovascular physiology: can arterial waveforms provide answers?

“…To our knowledge, there is no data on whether this contributes to sex differences in future CVD or predisposition to coronary heart disease. Thus, the clinical observations by Tagawa et al [19] should be interpreted with these caveats in mind. As the authors highlighted in their article, future studies should look to enrol patients with coronary disease and be performed longitudinally to determine causation.…”

“…Suboptimal SEVR may create a supply–demand imbalance and limit favourable cardiac function. In this issue of the Journal of Hypertension , Tagawa et al [19] hypothesized that the sex difference in SEVR may be mediated by differences in diastolic pressure decay.…”

“…Urgent strategies are required to tackle inequities in the prevention, diagnosis and treatment of CVD in women. The work by Tagawa et al [19] adds to the physiological understanding of sex differences in blood pressure waveform morphology and helps to focus the scientific community on the disparities in CVD between men and women. Maintaining this research momentum will lead to discoveries that will shift the known unknowns of sex differences in cardiovascular physiology and disease to known knowns.…”