J-Curve During Hypertension Control: Rationale for Not Lowering the Diastolic Pressure Below 85 mm Hg

To the Editor. — Overenthusiastic reduction of diastolic blood pressure in the treatment of essential hypertension could be detrimental. Cruickshank et al 1 reported a rise in the incidence of myocardial infarction in hypertensive patients when the diastolic pressure had been maintained below 85 mm Hg. Such an upward trend in the myocardial infarction events among the "well"-treated hypertensive individuals gave a Jshape appearance to the mortality curve. Alderman et al 2 found that those with diastolic pressure reduction between 7 and 17 mm Hg from an average of 102 mm Hg had a myocardial infarction rate of 0.9%, but if the reduction was lesser or greater than that range the infarction rates were 3.1% and 3.7%, respectively. This supports the observation by Cruickshank et al of 85 mm Hg as the lowest beneficial diastolic blood pressure reduction level (102 — 17 = 85). Subendocardial ischemia may result from a significant