Log in to MyACC
Pharmacological Blood Pressure Lowering for CVD Prevention
Quick Takes
- In contrast to present US and European guidelines for treatment of hypertension that are based on the presence or absence of ASCVD, 10-year ASCVD risk estimates, and focus on more recent trials, this meta-analysis of 48 trials conducted over 50 years in over 300,000 persons with and without baseline CVD, found that over an average of 4 years of follow-up, a 5 mm Hg reduction in systolic BP lowered the relative risk of major CV events by 10%.
- As with statins, the higher the baseline BP, the greater the absolute risk. But the authors suggest physicians should consider BP-lowering treatment for all persons at risk and that there may be benefit in persons whose BP is considered normal by present guidelines.
- The study was conducted and written by the well-respected Blood Pressure Lowering Treatment Trialists’ Collaboration housed at Oxford University, Oxford, UK. Amongst concerns includes the assumption that the quality of care, data and data entry, accuracy of BP measurement, advances in therapy unrelated to BP, and diagnostic accuracy has not changed over 5 decades.
Study Questions:
What is the effect of pharmacological blood pressure (BP) lowering treatment on the risk of major cardiovascular events (CVEs) by baseline levels of systolic blood pressure (sBP)?
Methods:
A meta-analysis was conducted in individual participant-level data from 48 randomized trials of BP lowering medications versus placebo or other classes of BP-lowering medications, or between more versus less intensive treatment regimens. Trials exclusively done in heart failure or short-term interventions in acute settings were excluded. Data from 51 studies published between 1972 and 2013 were obtained by the Blood Pressure Lowering Treatment Trialists’ Collaboration. Data were pooled to investigate the stratified effects of BP-lowering treatment in participants with and without prevalent CV disease (CVD) (i.e., stroke, myocardial infarction [MI], or ischemic heart disease before randomization), overall and across seven sBP categories (ranging from <120 to ≥170 mm Hg). Primary outcome analyzed as per intention to treat was a major CVE defined as a composite of fatal and nonfatal stroke, fatal or nonfatal MI or ischemic heart disease, or heart failure causing death or requiring admission to the hospital.
Results:
Data for 344,716 participants from 48 randomized clinical trials were available with 37 that included persons with and without previous CVD. About 50% in those without and 33% with CVD were women. Mean age was 65 years in both groups. Pre-randomization mean systolic/diastolic BP were 146/84 mm Hg in participants with previous CVD (46%) and 157/89 mm Hg in participants without previous CVD (54%). There was substantial spread in BP at baseline, with 19.8% of participants with previous CVD and 8.0% of individuals without CVD having a sBP of <130 mm Hg and 31% with and 19% without CVD having a diastolic BP <80 mm Hg. The relative effects of BP-lowering treatment were proportional to the intensity of sBP reduction.
After a median 4.15 years of follow-up (Q1–Q3 2.97–4.96), 42,324 participants (12.3%) had at least one major CVE (stroke 4.0%, ischemic heart disease 5.6%, congestive heart failure 2.4%). In those without previous CVD at baseline, the incidence rate for developing a major CVE per 1,000 person-years was 31.9 (95% confidence interval [CI], 31.3–32.5) in the comparator group and 25.9 (95% CI, 25.4–26.4) in the intervention group. In participants with previous CVD at baseline, the corresponding rates were 39.7 (95% CI, 39.0–40.5) and 36.0 (95% CI, 35.3–36.7), in the comparator and intervention groups, respectively. Hazard ratios associated with a reduction of sBP by 5 mm Hg for a major CVE were 0.91, 95% CI, 0.89–0.94 for participants without previous CVD and 0.89, 95% CI, 0.86–0.92, for those with previous CVD. In stratified analyses, there was no reliable evidence of heterogeneity of treatment effects on major CVE by baseline CVD status or sBP categories.
Conclusions:
In this large-scale analysis of randomized trials, a 5 mm Hg reduction of sBP reduced the risk of major CVD by about 10%, irrespective of previous diagnoses of CVD, and even at normal or high–normal BP values. These findings suggest that a fixed degree of pharmacological BP lowering is similarly effective for primary and secondary prevention of major CVD, even at BP levels currently not considered for treatment. Physicians communicating the indication for BP-lowering treatment to their patients should emphasize its importance on reducing CV risk rather than focusing on BP reduction itself.
Perspective:
If agreed upon, this exhaustive meta-analysis of BP-lowering trials conducted over 40 years makes the approach to BP treatment similar to that of statins. BP-lowering treatment could be considered for atherosclerotic CVD (ASCVD) prevention in any persons considered at increased risk. As with statins and low-density lipoprotein cholesterol, the higher the BP, the more relative risk reduction, but with BP, the absolute reduction of CVEs was surprisingly similar in those with and without CVD. To what degree the value of BP treatment would be altered by statins long term could not be tested nor whether the conclusions are appropriate for diabetics and those with chronic kidney disease. Importantly, there is value of BP treatment in persons with and without CVD at pressures below what is considered normal BP with no J-shaped curve.
The authors provide support for ignoring much of what is in the present guidelines including presence or absence of CVD, preferences for specific BP-lowering agents, therapeutic thresholds, targets, methods of measuring BP (home, office, ambulatory), and use of risk assessment with coronary calcium scoring and other 10-year risk estimates of ASCVD. The authors acknowledge the findings and recommended approach needs to be modified by patient preferences, and cost which would include drugs, monitoring, and treatment harms.
Clinical Topics: Cardiovascular Care Team, Dyslipidemia, Heart Failure and Cardiomyopathies, Prevention, Lipid Metabolism, Nonstatins, Novel Agents, Statins, Acute Heart Failure, Hypertension
Keywords: Antihypertensive Agents, Atherosclerosis, Blood Pressure, Blood Pressure Determination, Cholesterol, LDL, Heart Failure, Hydroxymethylglutaryl-CoA Reductase Inhibitors, Hypertension, Myocardial Infarction, Myocardial Ischemia, Pharmaceutical Preparations, Primary Prevention, Risk, Secondary Prevention, Stroke, Vascular Diseases
< Back to Listings
