Clinical research in cardiology : official journal of the German Cardiac Society 2017 11 21() doi 10.1007/s00392-017-1184-0
Coronary arteries perfuse cardiac myocytes during diastole. We hypothesized that marked lowering of diastolic blood pressure (DBP) is associated with increased risk of subclinical myocardial injury (SC-MI).
This analysis included 6107 participants without history of cardiovascular disease (CVD) from the third National Health and Nutrition Examination Survey. SC-MI was determined by a validated electrocardiogram-based scoring system. Logistic regression was used to examine the cross-sectional association between DBP (< 70, 70-80 mmHg (reference group), and > 80 mmHg; and per each 10 mmHg decrease, separately) with SC-MI across levels of systolic blood pressure (SBP) (< 120, 120-139, or > 140 mmHg).
In a multivariable model, DBP < 70 mmHg was associated with a higher risk of SC-MI [OR (95% CI) 1.40 (1.02, 1.94)] in participants with SBP > 140 mmHg. This association was consistent in subgroups stratified by age, race, diabetes, hypertension, obesity and smoking, but was stronger in women than in men [OR (95% CI) 1.58 (1.06, 2.37) vs. 1.10 (0.62, 1.94), respectively; interaction p value = 0.006]. Also, among participants with SBP > 140 mmHg, every 10 mmHg decrease in DBP was associated with a 12% increased odds of SC-MI [OR (95% CI) 1.12 (1.01, 1.23)]. No significant associations between DBP and SC-MI were observed in those with SBP < 120 mmHg or 120-139 mmHg, or between DBP > 80 mmHg and SC-MI in any of SBP levels.
Low DBP < 70 mmHg in those with SBP > 140 mmHg carries higher risk of SC-MI, especially in women. Further research is needed to understand the therapeutic implications of these findings.