Achieving target blood pressure is important especially for hypertensive patients who have an increased risk of cardiovascular events. The study determined whether achieved blood pressure targets conferred a benefit or is associated with an increased risk of cardiovascular-related adverse events.
Cardiovascular protection is imperative for patients with high risk of cardiovascular events. According to guidelines, achieving a target blood pressure of less than 140/90 mmHg may reduce the likelihood of such events. However, different cardiovascular outcomes like stroke and heart failure appear to be affected more by systolic blood pressure. Thus, cardiovascular risk reduction using blood pressure control may need to be personalized depending on the perceived benefit for the individual patient.
A study published in The Lancet determined the cardiovascular outcomes of achieving blood pressure targets for hypertensive, high-risk patients aged 55 years or older. The study analyzed data from previously reported outcomes of the ONTARGET and TRANSCEND trials which investigated ramipril, telmisartan, and their combination in a 56-month median follow-up. For both the studies, the participants were aged 55 years or older without heart failure, with a history of coronary artery disease, peripheral artery disease, transient ischemic attack, stroke or diabetes. Patients were recruited from 733 centers in 40 countries. ONTARGET participants were randomly assigned to oral ramipril, telmisartan or both while TRANSCEND participants were randomly assigned to telmisartan or placebo. In both cases, participants were resistant to ace-inhibitors. Complete data from 30,937 participants was analyzed. Primary composite outcomes were cardiovascular death, myocardial infarction, stroke, and hospital admission for heart failure. Patients were categorized according to their baseline and mean blood pressure on treatment using the following cut-offs: Systolic blood pressure (SBP) <120 mmHg, 120 to <140 mmHg, 140 to <160 mmHg, and 160 mmHg or greater. Similar cut-offs were made for diastolic blood pressure (DBP) at < 70mmHg, 70 to <80 mmHg, 80 to <90 mmHg, and 90 mmHg or greater.
Researchers found that participants who had baseline SBP of 140 to <160 mmHg had a higher rate of events such as composite outcome, cardiovascular death, stroke, hospital admission and all-cause death. Participants with baseline SBP of 160 or greater had higher rate of all events including myocardial infarction. With the exception of stroke, participants with DBP of <70 mmHg had higher risk of cardiovascular death, myocardial infarction, hospitalization, and all-cause death. While DBP of 90 mmHg or higher were associated with lower risk for the composite outcome, myocardial infarction, and hospitalization. Furthermore, researchers found that while on-treatment, participants with achieved SBP of <120 mmHg had higher risk of all outcomes except myocardial infarction. Similarly, participants with achieved SBP of 140 to 160 mmHg and 160mmHg or greater, had an increased risk for all events. Participants with achieved DBP of <70 mmHg also had increased risk for all events except for stroke while participants with DBP of 90 or greater had an overall increased risk for all related events. These results remained robust even after separating the analysis by comorbidities present at baseline or before an event. Finally, researchers wanted to determine by how much the increased risk could decline if changes in blood pressure were achieved. They found that when SBP increased from less than 120 mmHg, the risk for the primary outcome and all the associated risk was lower. Similarly, for participants with baseline SBP of 140-160 mmHg, a reduction of up to 30 mmHg was associated with lower risk of primary outcome. For participants with an SBP of 160 mmHg or more, a 50mmHg reduction reduced the primary outcome as well as all the associated events.
Overall, the researchers demonstrated that for a specific group of hypertensive patients with cardiovascular disease who are already on ACE inhibitors, achieving an SBP of 120-140 mmHg was associated with the lowest risk of primary cardiovascular outcome and all other related events. The results of the study indicate that achieved blood pressure on ACE treatment have varying benefits for different cardiovascular outcomes and is likely dependent on the patient’s baseline blood pressure.
Written By: Joan Zape, PhD(c)