Sex differences in pulse wave and subendocardial viability ratio in hypertensive patients

Objective: Myocardial ischemia represents the main cause of morbidity and mortality in hypertensive patients in both women and men, although some difference in pathophysiology and in the exposure to risk factors may explain the lower global cardiovascular risk of women. Sex differences in the structure and function of the cardiovascular system may affect the aortic pressure wave and the functional balance in myocardial perfusion determined by central aortic pressure, which may lead to myocardial ischemia and type 2 myocardial infarction. Design and method: In a population of 318 treated hypertensive patients (162 females, 156 males) referring to a single Hypertension centre (University of Trieste, Italy), we measured peripheral blood pressure and performed arterial applanation tonometry (PulsePen, DiaTecne, Italy) to determine central blood pressure waveform, aortic pulse wave velocity (PWV), augmentation index (AIx), pulse wave separation analysis with timing and amplitude of forward (fT, fP) and backward reflected (bT, bP) waves, and the subendocardial viability ratio (SEVR), i.e. the ratio between diastolic and systolic pressure-time index, as a risk marker of myocardial ischemia. Results: Despite similar peripheral systolic and diastolic blood pressure values, heart rate and PWV between sexes, females showed a longer forward pressure wave duration (119.8±38.6 vs 105.0±30.4 ms, p<0.0001) and lower amplitude (52.7±19,4 vs 57.1±19.3 mmHg, p = 0.039) compared to males. Backward pressure waved were similar in timing and amplitude between males and females. The difference in forward wave caused a marked higher AIx (19.5±12.4 vs 11.9±14.9, p<0.0001) and a lower SEVR (101.6±24.4 vs 108.5±27.7, p = 0.018) in women compared to men. Conclusions: Hypertensive women and men showed significant differences in forward pressure wave, causing a significant increase in AIx and a decreased SEVR in women compared to men. This may have important implications in sex-specific risk and myocardial ischemia.