TIME: CV Events Similar With Evening or Morning Dose of BP Meds

August 26, 2022

Patients with hypertension who took their antihypertensive medication in the evening or in the morning had similar rates of cardiovascular events over the following 5 years, in the much-anticipated TIME trial.

The trial, which contradicts several previous studies suggesting that evening dosing may be better, was presented today at the European Society of Cardiology (ESC) Congress 2022 being held in Barcelona, Spain. 

"The key message from this study is that taking antihypertensive medication in the evening makes no difference at all from taking it in the morning for the prevention of heart attacks, strokes, and vascular deaths," concluded TIME lead investigator Tom MacDonald, MBChB, MD, professor of clinical pharmacology & pharmacoepidemiology at the University of Dundee, UK.

The hazard ratio was 0.95 for the primary endpoint, a composite of hospitalization for nonfatal myocardial infarction, nonfatal stroke, or vascular death, in the intention-to-treat population.

Similar results, with a hazard ratio around 1, were seen for all the secondary outcomes and in all subgroups.

"There is nothing to see — not a smidge of a difference — in the primary outcome or any of the secondary outcomes," MacDonald commented.

The study also showed that evening dosing was not harmful in terms of falls or other adverse effects. MacDonald explained that taking the medication at night could result in an increase in nocturnal hypotension that may translate into more dizziness and falls if patients get up to use the bathroom during the night. "But, if anything, there were more dizzy turns during the day. The rate of fractures and hospitalization for fractures were identical in the two groups," he reported.

"Our take-home message is that patients can take their blood pressure tablets at any time they like — whenever is most convenient — as long as they take them. It's probably best to get into a routine of taking your tablets at the same time every day. That way you are more likely to remember to take them — but it won't matter if that is in the morning or in the evening," he said. 


MacDonald explained that the rationale for the study was that in some patients blood pressure does not drop at night, a group known as "non-dippers," and nighttime blood pressure is the best predictor of bad outcomes. In addition, previous studies have suggested that evening dosing of antihypertensives reduces nighttime blood pressure more effectively than daytime dosing.

"We and others thought that giving medication in the evening so that its peak effect occurs during the night might be beneficial," he said. "We did the trial because if it had turned out that taking tablets in the evening was beneficial, it would have been one of the cheapest and most cost-effective interventions known to man. It is a nice hypothesis and most people thought this would turn out with a benefit, but it actually didn't."

The study did find some differences in the blood pressure profile between the two dosing schedules.

"Our results show that when antihypertensive medication is taken in the morning then blood pressure is higher in the morning and lower in the evening. With evening dosing, blood pressure is lower in the morning and higher in the evening. It's not a huge difference — just 1 to 2 mmHg — and this didn't translate into any difference in outcomes," MacDonald said. 

"Ideally we need medication that lowers blood pressure effectively over the whole 24-hour period. That is where the push should be," he added.

The TIME study randomized 21,104 patients with treated hypertension to take their antihypertensive medication in the morning or in the evening. Baseline characteristics show the average age of participants was 65 years, 14% had diabetes, 4% were smokers, 13% had prior cardiovascular disease, and mean blood pressure at entry was 135/79 mmHg.

TIME was a pragmatic study, with participants recruited from primary and secondary care registering on the internet, and information on hospitalizations and deaths obtained from participants by email and through record linkage to national databases, with further data gathered from family doctors and hospitals and independently adjudicated by a blinded committee.

The median follow-up duration was 5.2 years, but some patients were followed for over 9 years.

The primary endpoint occurred in 362 (3.4%) participants in the evening-dosing group (0.69 events per 100 patient-years) and 390 (3.7%) in the morning-dosing group (0.72 events per 100 patient-years), giving an unadjusted hazard ratio of 0.95 (95% CI, 0.83 - 1.10; P = .53).

What to Recommend in Clinical Practice?

Outside commentators had mixed opinions on how the TIME results should be applied to clinical practice.

Discussant of the TIME study at the ESC Hotline session, Rhian Touyz, MBBCh, University of Glasgow, UK, said the trial asked a "very pertinent" question and the data "are certainly provocative."

She cited several previous studies suggesting that evening dosing improved nighttime blood pressure and reduced cardiovascular events.

"The finding of no difference in event rate in the TIME study is therefore very intriguing."

She pointed out that other studies have shown benefit of nighttime dosing in certain patient groups such as those with sleep apnea, non-dippers, and those with nocturnal hypertension.  

"With all these previous data, we have to ask why the TIME trial has produced this unexpected result," she said.

MacDonald replied that the study was completely neutral. "That is the result and I believe it is definitive. I'm absolutely confident that we did the study as best we could. All events were adjudicated. Compliance was quite good at 60%. I can't believe there is anything in our data that invalids these results," he said. "If we want to look at specific groups of patients then we have to do larger studies in those particular groups, but for a general population of hypertensive patients we didn't find any difference at all in morning versus evening dosing."

The TIME results are in direct contradiction of a previous high-profile study — the Hygia Chronotherapy Trial — published in 2020, which found a large protective effect of nocturnal dosing on cardiovascular events, and attracted much media attention. But this study has subsequently attracted criticism, with an "expression of concern" and a commentary raising several questions. 

And a systematic review from the International Society of Hypertension (ISH) published earlier this month concludes that previous trials of bedtime antihypertensive dosing had "major flaws."  

The review notes that three ongoing, well-designed, prospective, randomized controlled outcome trials are expected to provide high-quality data on the efficacy and safety of evening or bedtime versus morning drug dosing.

"Until that information is available, preferred use of bedtime drug dosing of antihypertensive drugs should not be routinely recommended in clinical practice. Complete 24-h control of BP should be targeted using readily available, long-acting antihypertensive medications as monotherapy or combinations administered in a single morning dose," it concludes.

On the new TIME results, lead author of the ISH review, George Stergiou, MD, commented to theheart.org | Medscape Cardiology: "The benefits of bedtime dosing were not confirmed — as we well expected. So, I think bedtime drug dosing should not be routinely recommended in clinical practice."

Although the TIME trial did not show any harms with bedtime dose, Stergiou added, "I am not too happy with their conclusion that patients should do as they wish. The vast majority of well-conducted outcomes studies which we use to guide the treatment of hypertension administered all drugs in the morning."

One of the authors of the commentary criticizing the Hygia trial, Sverre E. Kjeldsen, MD, University of Oslo, Norway, told theheart.org | Medscape Cardiology that the TIME trial was an important study, far more reliable than the Hygia study, and the results were as expected.

"From a scientific point of view, patients have a choice as to when to take their medication, but we strongly recommend taking blood pressure meds in the morning. Adherence is proven to be worse at bedtime. However, physicians may still consider bedtime dosing in patients proven to have high night-time blood pressure," Kjeldsen added.

Lead investigator of the Hygia study, Ramón C. Hermida, PhD, University of Vigo, Spain, told theheart.org | Medscape Cardiology he and his coauthors are standing by their results.

"The design and conduct of the TIME trial does not comply with the quality requirements listed in the guidelines by the International Society for Chronobiology for conducting chronotherapy trials in hypertension, and the results are not in-line with the reported findings of multiple clinical trials on the effects of timed hypertension treatment on blood pressure control and circadian pattern regulation, kidney function, and cardiac pathology," Hermida said.

Chair of an ESC press conference on the TIME study, Steen Dalby Kristensen, MD, Aarhus University Hospital, Skejby, Denmark, said he thought the trial was "very well done."

The TIME results, he said, "are quite clear, whether you take your blood pressure tablets in the morning or the evening it makes no difference for the hard outcomes that we fear in patients with hypertension.  

"I think that this solves a question that we've had for a long time now," he commented to theheart.org | Medscape Cardiology. "Even though there were some changes in the blood pressure measured in the evening or in the morning it doesn't seem to matter in terms of clinical events. This means that life might be a bit easier for patients in that they can choose when they take their medication at the time most convenient to them.  

"I don't know why previous studies suggested such a big benefit of evening dosing," he added. "I would say the TIME trial is a more definitive result. It is a very important trial."

Dipti Itchhaporia, MD, University of California, Irvine, and immediate past president of the American College of Cardiology, agreed that the TIME study was well conducted.

"On the basis of these results I wouldn't recommend a specific time," she said. "That's kind of a relief, as it can be difficult to always take medications at a set time and this gives patients more flexibility."

She suggested a possible alternative approach for patients taking more than one drug — taking one in the morning and the other in the evening. "That might give better 24-hour coverage."

The study was funded by the British Heart Foundation. MacDonald has reported receiving research funding from Novartis and consulting fees from Novartis and AstraZeneca.

ESC Congress 2022. Presented August 26, 2022.

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