People in their thirties with ‘normal’ blood pressure which rises throughout their life may face an increased risk of heart disease, stroke or heart failure in later life, researchers from University College London (UCL) have suggested.
Tracking more than 500 people over four decades, the study found that individuals with higher blood pressure in their thirties and forties, who had either maintained high blood pressure or saw it steadily increase over time, had significantly reduced blood flow to the heart muscle by the age of 77.
The findings, published in the journal Circulation: Cardiovascular Imaging and funded by the British Heart Foundation, highlight how monitoring and managing blood pressure trajectories throughout adulthood can reduce the long-term burden of cardiovascular disease.
Using MRI scans, the researchers examined how the magnitude and rate of blood pressure rise affect blood flow and heart scarring in later life.
Blood pressure and later cardiac risk
The trial, known as MyoFit46, recruited 505 participants from the National Survey of Health and Development, which follows thousands of people over decades, collecting blood pressure readings at the ages of 36, 43, 53, 62, 69 and 77 years. All participants in this trial were born in one week in March 1946.
Lifelong patterns of slightly higher or faster-rising blood pressure, even within the ‘normal’ range, were strongly linked to poorer heart muscle blood flow and higher cardiovascular risk at age 77.
Damage to the heart muscle was shown to accumulate over decades, and for every 10 mmHg higher systolic blood pressure (SBP) between the ages of 36 and 69, there was a reduction of up to 6% in stress myocardial blood flow (sMBFN) when participants were 77 years old.
The damage done later in life was especially high if the blood pressure rises were seen between the ages of 43 and 63. When SBP rose from 120 to 140 mmHg during that period, signifying ‘high-normal’ rather than hypertensive readings, blood flow to the heart muscle was 18-24% lower at age 77.
Senior author Dr Gaby Captur, consultant cardiologist at the Royal Free London NHS Foundation Trust and associate professor at UCL’s Unit for Lifelong Health and Ageing and the Institute of Cardiovascular Science, said: ‘Small, steady increases in blood pressure through adulthood, even if you have a “normal but high” reading, can be quietly damaging the heart, long before symptoms appear. Your blood pressure in your thirties can affect the heart 40 years later.’
The researchers also found that individuals with more prolonged exposure to high blood pressure were at the highest risk. Every 1% reduction in blood flow to the heart corresponded to a 3% higher risk of heart attack, stroke or heart failure. Participants with systolic pressure 10 mmHg above ‘normal’ from ages 36 to 77 had up to 11% lower heart blood flow by age 77, associated with a 33% greater risk of experiencing a major cardiovascular event, the researchers said.
Even people with well-controlled blood pressure at age 77 saw effects apparently caused by higher blood pressure at younger ages, they added.
The researchers suggested that maintaining SBP below 120 mmHg and providing patients with guidance on medications or lifestyle changes to support heart health would be beneficial in preserving vital blood flow to the heart in later years.
Dr Cristian Topriceanu, PhD fellow at the UCL Institute of Cardiovascular Science and first author of the study, said that analysing blood pressure trajectories over a lifetime, rather than looking at one-off readings, gives clinicians a new way to think about risk.
He added: ‘Spotting and treating those changes earlier could help doctors spot those at risk of heart attacks, strokes and heart failure in later life.’
A version of this article was originally published by our sister publication Nursing in Practice.