High Blood Pressure: an Experimental Research

High blood pressure is a significant public health concern. It is extremely widespread and a risk factor for numerous adverse health consequences, particularly coronary heart disease and stroke. The research conducted by the SPRINT group “A Randomized Trial of Intensive versus Standard Blood-Pressure Control; was designed to provide data that a more intensive systolic blood pressure goal of <120 mmHg will have a greater cardiovascular benefit versus the standard goal of <140 mmHg

The experimental research was a randomized, controlled, open-label trial that was conducted at 102 clinical sites, which was organized into 5 clinical center networks in the United States. Participants were required to meet all the following criteria: At least 50 years, Systolic blood pressure of 130 to 180 mm Hg Increased risk of cardiovascular events. Eligible participants were assigned to a systolic blood-pressure target of either less than 140 mm Hg for the standard-treatment group or less than 120 mm Hg in the intensive-treatment group. The selected participants were then seen monthly for the first 3 months and every 3 months thereafter.

During the study, 9361 eligible patients were randomized to the treatment groups and followed for a median of 3.26 years. Table 1 in the article shows the baseline characteristics of the included patients: Mean age was 68 years old and 64% were men. Medications for participants in the intensive-treatment group were adjusted monthly to target a systolic blood pressure of less than 120 mmHg. Whereas, medications for individuals in the standard-treatment group were adjusted to target a systolic blood pressure of 135 to 139mm Hg, and the dosage decreased if systolic blood pressure was less than 130 mm Hg on a single visit or less than 135 mm Hg on two follow up visits. The authors stated that “Dose adjustment was based on a mean of three blood-pressure measurements at an office visit while the patient was seated and after 5 minutes of quiet rest; the measurements were made with the use of an automated measurement system”.

The study ended early after the data and safety monitoring board noted that the primary outcome exceeded the monitoring boundary at two consecutive points. However, after 1 year, the mean systolic blood pressure for participants in the intensive-treatment group was 121.4mm and 136.2mm Hg for those in the standard-treatment group. Throughout the 3.26 years of follow up, the mean systolic blood pressure was 121.5 mm Hg in the intensive-treatment group and 134.6 mm Hg in the standard-treatment Group. There were serious adverse events that befell 1793 participants in the intensive-treatment group and 1736 participants in the standard-treatment group. A total of 220 participants in the intensive-treatment group and 118 participants in the standard treatment group had serious adverse events that were classified as “possibly or definitely related to the intervention”.

The main finding of the trial was the lower rate of the primary outcome (cardiovascular events including CVD mortality) in the intensive group compared to standard group. As demonstrated in table 2, The relative risk of death from cardiovascular causes was 43% lower with the intensive intervention than with the standard treatment. The research showed that among adults with hypertension but without diabetes, lowering systolic blood pressure to a target goal of less than 120 mm Hg, as compared with the standard goal of less than 140 mm Hg, resulted in significantly lower rates of fatal and nonfatal cardiovascular events and death from any cause.

Conclusion

The authors presented a strong recommendation, recommending that clinicians implement the new BP target: “In selected high cardiovascular risk populations where a more intense treatment can be considered, aiming to a target of <120 mmHg systolic blood pressure can improve cardiovascular outcomes”. The authors determined that in adult non-diabetic patients 50 years or older with an increased cardiovascular risk, targeting a systolic BP of less than 120 mmHg, as compared with less than 140 mmHg, resulted in lower rates of fatal and non-fatal major cardiovascular events and death from any cause, although significantly higher rates of some adverse events were observed in the intensive-treatment group.