Taking antihypertensive medications at bedtime results in improved blood pressure control and a markedly diminished risk of major cardiovascular events, according to results presented at the European Society of Cardiology annual meeting.
Led by clinicians from Spain, the Hygia Chronotherapy Trial randomised 19,084 patients to taking their antihypertensive medication on waking or at bedtime, and followed them for an average of 6.3 years.
The results from 48-hour ambulatory BP monitoring showed that patients who took their medication at bedtime had nearly half the risk (45% reduction) of dying or having myocardial infarction, stroke, heart failure or requiring coronary revascularisation, compared to patients who took their medication on waking.
Patients of the bedtime, compared with the upon-waking, treatment-time regimen showed significantly lower hazard ratio of the primary CVD outcome [0.55 (95% CI 0.50–0.61), P < 0.001] and each of its single components (P < 0.001 in all cases), including cardiovascular death [0.44 (0.34–0.56)], myocardial infarction [0.66 (0.52–0.84)], coronary revascularisation [0.60 (0.47–0.75)], heart failure [0.58 (0.49–0.70)], and stroke [0.51 (0.41–0.63)].
Lead investigator Professor Ramón Hermida, Director of the Bioengineering and Chronobiology Labs at the University of Vigo, said current hypertension guidelines did not mention or recommend any preferred treatment time, and morning ingestion has been the most common recommendation by physicians, based on the misleading goal of reducing morning blood pressure levels.
He noted that the Hygia Project has reported previously that average systolic BP when a person is asleep is the most significant and independent indication of cardiovascular disease risk, regardless of BP measurements taken while awake or when visiting a doctor.
Data from ambulatory BP monitoring showed that patients taking their medication at bedtime had significantly lower average BP both at night and during the day, and their BP dipped more at night, when compared with patients taking their medication on waking.
“The findings from the Hygia Chronotherapy Trial and those previously reported from the Hygia Project indicate that average BP levels while asleep and night-time BP dipping, but not day-time BP or BP measured in the clinic, are jointly the most significant BP-derived markers of cardiovascular risk,” he said.
Furthermore, there were no studies showing that treating hypertension in the morning improves the reduction in the risk of cardiovascular disease.
“Accordingly, round-the-clock ambulatory blood pressure monitoring should be the recommended way to diagnose true arterial hypertension and to assess the risk of cardiovascular disease.
“In addition, decreasing the average systolic blood pressure while asleep and increasing the sleep-time relative decline in blood pressure towards more normal dipper blood pressure patterns are both significantly protective, thus constituting a joint novel therapeutic target for reducing cardiovascular risk.”