Millions Take Blood Pressure Drugs, but Many May Be Missing Their Heart-Protective Benefits

Blood pressure drugs can prevent heart attacks and strokes, but their protection may fade when too many doses are missed.

New research presented at ESC Congress 2026 provides some of the clearest evidence yet that consistently taking antihypertensive medication is essential to receiving its cardiovascular benefits. The analysis used randomized trial data to separate the effects of adherence from other influences that can complicate observational research.

An estimated 1.4 billion adults ages 30 to 79 worldwide have high blood pressure (hypertension). Often producing no obvious symptoms, the condition can gradually damage blood vessels and organs while increasing the risk of heart disease, stroke, and heart failure. Medication can substantially reduce that danger, yet roughly half of patients do not follow their prescribed treatment consistently.

Testing the Consequences of Missed Doses

“We have evidence that poor adherence to antihypertensive medication is associated with worse outcomes,” said presenter Qianqian Yang of the University of Oxford, UK. “However, previous data has come from observational studies and could be confounded by other factors. We undertook an analysis of randomized trial data to assess the true impact of adherence on the benefits of antihypertensive treatment.”

The researchers combined individual data from 91,339 participants enrolled in nine clinical trials. Each study compared an antihypertensive treatment (intervention group) with another approach (comparator group: either placebo or a less-intensive regimen). Participants were considered to have higher adherence if they took at least 80% of their assigned treatment and lower adherence if they fell below that threshold.

Even within closely monitored clinical trials, consistent medication use declined over time. “A decline in adherence over time was apparent, even in the structured setting of trials,” Yang said. The proportion of participants with higher adherence dropped from 88% during the first year to 79% by year five.

Greater Adherence, Greater Protection

Treatment produced a larger improvement among people who took their medication more consistently. In the higher adherence group, the intervention lowered systolic blood pressure by 5.2 mmHg compared with the alternative treatment. Among participants with lower adherence, the difference was only 3.0 mmHg.

Systolic pressure is the first number in a blood pressure reading and reflects the force exerted against artery walls when the heart contracts. Although a difference of a few millimeters of mercury may appear modest for one person, even small average reductions can translate into fewer cardiovascular events across a large population.

The researchers next examined major cardiovascular diseases, including stroke, myocardial infarction or ischemic heart disease, and heart failure that resulted in hospitalization or death. Among participants with higher adherence, the antihypertensive treatment reduced these events by a significant 11% compared with the alternative approach. No significant reduction was detected among those with lower adherence.

“Notably, our results reinforce the saying that ‘drugs don’t work in patients who don’t take them.’ Patients with lower adherence derived little or no cardiovascular benefit, whereas those with higher adherence had greater reductions in blood pressure and prevention of cardiovascular events,” Yang said.

Making Treatment Easier to Follow

Side effects, cost, complicated schedules, uncertainty about whether treatment is necessary, and the absence of noticeable symptoms can all make long-term therapy difficult. Because hypertension often feels harmless, patients may receive little immediate feedback when they skip a dose.

The authors recommend making adherence assessment and patient education more prominent in hypertension care. Practical measures could include simplifying treatment schedules, combining several medications into one pill, and prescribing longer-acting drugs that provide more protection when an occasional dose is missed.

Professor Felix Mahfoud, Chair of the ESC Communication Committee, said, “For years, we have neglected non-adherence to medication as a cause for uncontrolled hypertension. Assessment of adherence should become a routine part of hypertension care so patients do not miss out on life-saving benefits. As healthcare providers, we are here to have open, non-judgmental conversations with our patients about any barriers they may have to taking medication to help improve adherence.”

Meeting: ESC Congress 2026

The research was funded by the British Heart Foundation (FS/19/36/34346).

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