Core tip: the study found that most high-risk patients with systolic blood pressure between 130 and 120 mmHg are safe, and improve the prognosis; for patients with low systolic blood pressure after treatment, antihypertensive drugs should be reduced to avoid adverse events, because treatment to the target value does not mean that the blood pressure is reduced below the target value.
The analysis of two antihypertensive trials showed that the use of antihypertensive drugs to minimize blood pressure in patients with coronary heart disease, diabetes mellitus, or other cardiovascular-related diseases is not necessarily the best strategy, because the J-curve pattern of the prognosis of such patients is found.
The results of the study, published in Lancet on April 5, 2017, showed that systolic blood pressure drop below 120 mmHg was associated with increased risk of cardiovascular outcomes (excluding myocardial infarction and stroke) in the target and transcend randomized trials, as well as diastolic blood pressure below 70 mmHg. The benefit of specific blood pressure values for different outcomes may vary, and this may also be associated with baseline risk in patients with hypertension, the researchers said. The benefit of intensive hypotension in patients at high risk of stroke may be greater than that in patients at high risk of myocardial infarction and cardiovascular death.
Sprint research
These results are obviously contrary to the results of the sprint study (systolic blood pressure ≥ 130 mmHg were randomly given intensive or standard antihypertensive therapy). The sprint study found that systolic blood pressure drop to 120 mmHg was associated with a significant reduction in cardiovascular events (30%) and all-cause mortality (25%).
However, does the sprint study mean that all patients should lower their blood pressure below 120mmhg? Some studies suggest that the management of blood pressure should be based on the individual risk of patients, rather than blindly strengthen blood pressure reduction. This analysis suggests that it may be a bad thing for patients to drop their blood pressure too low, and future guidelines need to give a target range of blood pressure rather than a single upper limit.
On the one hand, blood pressure above 140mmHg is mostly associated with increased risk, and treatment is absolutely necessary at this time. But at the same time, it should be closely monitored to prevent hypotension.
Ontarget and transcend tests
The researchers conducted a secondary analysis of the target and transcend trials involving 30937 cardiovascular high-risk patients over the age of 55.
In the target trial, 25127 patients were randomized to receive ramipril 10 mg/day (8402), telmisartan 80 mg/day (8386), or combination therapy (8334). In the transcend trial, 5810 ACEI tolerant patients were randomly treated with telmisartan 80 mg/day (2903) or placebo (2907).
The average follow-up period was 56 months. There was no difference in the incidence of major composite endpoints (cardiovascular death, myocardial infarction, stroke, and hospitalization for heart failure) between the two groups. The analysis also found that baseline SBP ≥ 140 mmHg was associated with an increased risk of overall prognosis compared with systolic blood pressure between 120 and 140 mmHg. The researchers also found that baseline diastolic blood pressure < 70 mmHg was associated with an increased risk of most outcomes.
Compared with patients with a systolic blood pressure of 120-140 mmHg, the cardiovascular risk (cardiovascular death and all-cause death) was increased in patients with systolic blood pressure below 120 mmHg (HR 1.14). There was no significant correlation between MI, stroke, or hospitalization.
The data showed that the mean systolic blood pressure after treatment could predict the outcome of patients more accurately than baseline systolic blood pressure, and the risk of cardiovascular death and all-cause death increased in patients with a systolic blood pressure of 130 mmHg, but no increased risk of stroke.
The researchers believe that it is safe for most high-risk patients to reduce their systolic blood pressure to between 130 and 120 mmHg, and improve the prognosis; for patients with lower systolic blood pressure after treatment, antihypertensive drugs should be reduced to avoid adverse events, because treatment to the target value does not mean that the blood pressure is reduced below the target value.