BEIJING, China — Lowering your blood pressure is a vital part of maintaining good heart health in the here and now. Unfortunately, a new study finds, for people with a history of hypertension, one year of normal blood pressure may be too little, too late to avoid heart disease. Researchers find people with healthy blood pressure currently but who suffered from high blood pressure for several years in the past are still at a higher risk of death from cardiovascular disease (CVD).
CVD is the leading cause of death globally. The condition can lead to various life-threatening events such as a heart attack, stroke, and coronary artery disease. One of the major risk factors for developing heart disease is having high blood pressure, or hypertension.
Dr. Jing Liu from the Beijing Institute of Heart, Lung, and Blood Vessel Diseases decided to explore exactly how much hypertension increases a patient’s chances of developing CVD. Liu and researchers followed up on recent studies which discovered that heart disease risk can still be high even if a person’s current blood pressure is below the threshold of hypertension.
Cumulative blood pressure may be the key
Those findings led the team to suspect that a patient’s cumulative blood pressure over several years may contribute to their current CVD risk. Dr. Liu’s team analyzed data from a 26-year review of the Chinese Multi-provincial Cohort Study-Beijing Project during their study.
First, researchers looked at the BP levels of 2,429 participants over 15 years, from 1992 to 2007. All of these individuals were free of heart disease in 2007. Study authors then looked at the number of CVD cases developing among these participants from 2007 to 2018.
Over that time, 207 of these patients experienced a CVD event. Moreover, the results show these incidents were more common among patients with a higher cumulative BP.
Specifically, the study finds maintaining an average BP of 131/83 mm/Hg for 15 years — which is only moderately over the healthy 120/70 mmHg mark — increases the risk of heart disease. This risk remained constant even when a patient’s BP was within the healthy threshold in 2007.
One year of high blood pressure is not as bad as a history of hypertension
On the other hand, if a participant’s blood pressure was high in 2007 but they had a healthy cumulative BP over the previous 15 years, they displayed a lower risk of CVD. Based on these findings, study authors conclude that doctors need to start looking at a patient’s long-term history of hypertension, rather than a single reading during any given year.
“Our findings show that long-term exposure to high blood pressure may increase your risk of cardiovascular disease, although your current blood pressure level is lower than the diagnostic criterion of hypertension. For example, a person with current blood pressure level of 120/70 mmHg, which is within the normal range, could still be at a higher risk of contracting a cardiovascular disease in the future if his/her blood pressure level used to be higher than 130/80 mmHg for a long time, say years, in the past,” Dr. Liu says in a media release.
“This study underscores the importance of starting BP management early,” Dr. Liu continues. “We wish for our research to guide health care providers to pay attention to a patient’s previous blood pressure levels and duration for which BP has been high, in addition to current levels. This will help to identify individuals at a higher risk of cardiovascular disease in the future.”
Researchers add that waiting until blood pressure levels become regularly high before starting medication may be a dangerous mistake.
The findings appear in the Chinese Medical Journal.