Intensive blood pressure control in older patients associated with decreased cardiovascular events
Intensive blood pressure control led to a decreased rate of major adverse cardiovascular events, including cardiovascular death and heart failure, in older adults with hypertension, the study concluded.
In patients 65 years of age and older, intensive blood pressure control was associated with a decreased rate of major cardiovascular events (MACE), according to a recent analysis of four high-quality trials.
Researchers searched the literature for randomized controlled trials that compared intensive blood pressure lowering with standard or liberal blood pressure lowering in older adults with hypertension. Studies were selected if they included long-term data on cardiovascular events and safety outcomes. The current study evaluated four cardiovascular outcomes—MACE (as defined by each individual trial), cardiovascular death, stroke, myocardial infarction, and heart failure—as well as serious adverse events and renal failure. Results were published online by the Journal of the American College of Cardiology on Jan. 30.
Four high-quality trials with a total of 10,857 patients were included in the study. Overall, 5,437 patients were randomly assigned to intensive blood pressure control, defined as a systolic blood pressure target below 140 mm Hg, and 5,420 were randomly assigned to standard blood pressure control. Mean follow-up was 3.1 years. In the four included trials, the final mean systolic blood pressure achieved in the intensive groups versus standard groups was 135.9 mm Hg versus 145.6 mm Hg, 123.4 mm Hg versus 134.8 mm Hg, 136.6 mm Hg versus 142.0 mm Hg, and 135.7 mm Hg versus 149.7 mm Hg.
The researchers found that intensive blood pressure lowering was associated with reductions in MACE, cardiovascular death, and heart failure (relative risks, 0.71 [95% CI, 0.60 to 0.84], 0.67 [95% CI, 0.45 to 0.98], and 0.63 [95% CI, 0.43 to 0.99], respectively) compared with standard blood pressure lowering. No statistically significant difference in myocardial infarction or stroke rates or in rates of serious adverse events or renal failure was seen between groups. However, in a fixed-effects model, intensive blood pressure lowering was associated with an increased risk for renal failure (relative risk, 2.03; 95% CI, 1.30 to 3.18).
The authors noted that their meta-analysis included only four trials that varied in inclusion and exclusion criteria as well as in antihypertensive therapy and outcome definitions. In addition, one of the included trials, SPRINT-SENIOR, used a target systolic blood pressure of below 120 mm Hg in the intensive group while the other trials used a target of below 140 mm Hg. They also noted that patient-level data were not available and that their results cannot be generalized to patients with diabetes and cardiovascular disease because the included trials did not study many of these patients.
Despite these limitations, the authors concluded that intensive blood pressure control led to a decreased rate of MACE, including cardiovascular death and heart failure, in older adults with hypertension. They noted that although data on adverse events were limited, intensive blood pressure lowering may be linked to an increased renal failure risk. “When considering more intensive [blood pressure] control in the elderly, clinicians should carefully balance benefits against potential risk,” the authors wrote.
The authors of an accompanying editorial noted that the results of the meta-analysis depended largely on SPRINT-SENIOR, which reported higher rates of cardiovascular events than the other three included trials, and agreed with the study authors' concerns about the differences between the studies, including differences in antihypertensive regimens. They said that the main question is whether SPRINT results can be applied to a broader population of older hypertensive patients, most critically because SPRINT measured blood pressure with an automated device in the office after five minutes of rest, leading to values 5 to 10 mm Hg lower than those from routine office-based readings. Because of this, the editorialists wrote, “treating all older hypertensive patients to a systolic [blood pressure] target of <120 mm Hg using non-SPRINT methodology is equal to a [blood pressure] between 110 and 115 mm Hg by SPRINT methods. This may not be beneficial and could actually be harmful.”
The editorialists stressed that older patients are heterogeneous and that those who are frail are often underrepresented in clinical trials. However, in SPRINT and in the National Health and Nutrition Examination Survey (NHANES), frail elderly people did not seem to do worse at lower blood pressure targets, they said. The editorialists concluded that they supported lower targets in older patients who could tolerate them but reiterated the study authors' conclusion that clinicians should pay careful attention to risks and benefits in this group.