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The Veterans Affairs (VA) Electronic Health Record (EHR), operational since 1998 has all elements of patient care in 124 VA Medical Centers and 820 VA clinics. Vital signs contain blood pressure with clinical reminders to assure a blood pressure recording at least once a year and on each visit if the previous pressure was elevated. The data is aggregated for analysis.
We examined average systolic BP (ASBP) after HTN was diagnosed between 2000-2014 in relation to all-cause mortality and nonfatal cardiovascular events of stroke, acute kidney injury (AKI), CHF and myocardial infarction (MI). Hypertension (HTN) was defined as systolic BP >140 or diastolic BP >90 mmHg on 3 separate days. The level of BP control was determined by averaging all available BPs after HTN was diagnosed. Eight levels of ASBP were examined for the whole population, by racial groups (White and Black), age and for presence or absence of diabetes.
There were 8,813,000 patients, of which 3,160,608 had HTN with 83.5% of VA patients within guidelines for control. Optimal BP control (lowest mortality) was between 120 and 130 (see graph). Mortality increased to above 19% for all patients when ASBP was above 150 or below 110 (P<0.001) forming a U shaped curve. Blacks had better survival than Whites at similar levels of BP control. Blacks had higher non-fatal CV event rates than whites (47% increase in stroke), (40% increase HF), and (64%increase in kidney failure). At mean BP control rates between 120 - 140 mmHg non-fatal CV events of stroke and kidney failure were reduced among Blacks but not among Whites.
The mean systolic blood pressure control that produced the lowest mortality was 120 - 130, with a U shaped curve showing increased mortality above 150 and below 110. For 3.160 million VA patients the average systolic BP control was within guidelines in 83.4% of patients.