POISE-3: Two Perioperative BP Strategies Give Similar Results in Noncardiac Surgery

WASHINGTON, DC—Two strategies for managing blood pressure during noncardiac surgery—one for avoiding hypotension and one for avoiding hypertension—provide comparable effects on hemodynamics and major vascular outcomes, the POISE-3 trial shows.

At 30 days, the rate of a composite of vascular death nonfatal myocardial injury after noncardiac surgery (MINS), stroke, or cardiac arrest at 30 days was 13.9% among patients who had their antihypertensive medications held around the time of the operation and 14.0% among those who didn’t (HR 0.99; 95% CI 0.88-1.12).

The target mean arterial pressure (MAP) intraoperatively was higher in the hypotension-avoidance group (≥ 80 mm Hg vs ≥ 60 mm Hg). There were, however, only small average differences in systolic BP and heart rate between trial arms.

Since we know that the two options are both reasonable options, maybe we can listen more to what the patient wants. Maura Marcucci

The results address questions around MAP targets during surgery and the handling of antihypertensive medications in the perioperative period, which physicians wrestle with on a daily basis, according to Maura Marcucci, MD (McMaster University, Population Health Research Institute, Hamilton, Canada), who presented the results at the American College of Cardiology (ACC) 2022 Scientific Session earlier this week.

“POISE-3 does not show that hemodynamics doesn’t matter. It does matter,” she said at a press briefing, adding that “we should look to evaluate other perioperative interventions that might affect hemodynamics in a favorable way so that we can see an effect also on clinical outcomes.”

For James McClurken, MD (Doylestown Health, PA), the POISE-3 results are useful for all physicians who care for patients undergoing surgery, not just anesthesiologists. In the past, he noted to reporters, certain medications would be held before an operation, which can result in unstable BP.

“This nicely showed, with data point acquisition across their global array of hospitals, that in patients without class III or IV heart failure or very weak hearts, it’s not necessary to hold medicines the day before, so this is a paradigm shift of what has been done traditionally,” McClurken commented.

No Major Differences Between Strategies

Not only do patients undergoing noncardiac surgery frequently have major vascular complications, but also they commonly develop hemodynamic abnormalities, including hypotension in more than 25%, Marcucci said. Most of these patients are taking chronic antihypertensive therapy, and although these medications are often continued in the perioperative period, there is variation in practice.

Some studies have suggested that withholding ACE inhibitors/ARBs can reduce perioperative hypotension and vascular complications, whereas others have shown that withholding beta-blockers may worsen outcomes. When it comes to intraoperative MAP targets, it’s common to aim for 60 mm Hg or higher, but there are observational data suggesting even higher levels may be better. Overall, Marcucci said, there’s uncertainty about the optimal way to manage BP around the time of noncardiac surgery.

POISE-3 was a partial 2x2 factorial trial. The larger part, which randomized more than 9,500 patients to tranexamic acid or placebo to assess the impact on bleeding, was reported earlier at ACC 2022.

For the BP part, investigators randomized 7,490 patients 45 or older (mean age 70; 56% men) at 110 centers across 22 countries. All were undergoing inpatient noncardiac surgery, were deemed to be at increased risk for perioperative cardiovascular events, and were chronically taking at least one antihypertensive medication. On average, patients were taking two antihypertensives, with 27% taking three or more. Most (72%) were on an ACE inhibitor/ARB, and 44% were on a beta-blocker.

All patients were told to not take their BP-lowering drugs the night before or morning of surgery and to bring the medications with them to the preoperative holding area. At that point, patients were randomized to a hypotension-avoidance strategy or a hypertension-avoidance strategy.

For those in the former group, their ACE inhibitor/ARB was stopped in the preoperative period, with other antihypertensive medications held according to an algorithm based on systolic BP, with similar steps taking on the first two postoperative days. During the operation, the MAP target was 80 mm Hg or higher.

In the hypertension-avoidance group, patients continued to take their chronic antihypertensive drugs during the preoperative period, with those medications restarted after surgery. The intraoperative MAP target was 60 mm Hg or higher.

Compliance was good when it came to the MAP targets, Marcucci reported. Adherence to the medication protocols, however, was less-than-optimal, ranging from 57% to 75%.

No major differences in vascular outcomes were observed between trial arms, with statistically similar rates of the primary composite outcome, MINS, MINS not meeting the universal definition of MI, MI, stroke, vascular and all-cause mortality, and other tertiary endpoints.

The findings were not modified by the tranexamic acid intervention (P = 0.54 for interaction), and were consistent across subgroups defined by type and number of antihypertensive drugs, systolic BP, NT-proBNP level, and type of surgery. Compliance with the study protocols at the center level didn’t influence the vascular outcome or hemodynamic results.

Looking to Tailored Management

Commenting for TCTMD, ACC President Edward Fry, MD (Ascension Medical Group, Indianapolis, IN), called this a very practical trial, as cardiologists often get calls from anesthesiologists regarding what should be done about a patient’s antihypertensive therapy during elective noncardiac surgery. “There’s very rarely enough thought given to how to manage those medications in a protocolized way. There’s huge variability in terms of how that’s done,” Fry said.

This is a paradigm shift of what has been done traditionally. James McClurken

These new results show that both strategies are effective at hitting the “sweet spot” of BP, he said, suggesting that physicians can refer to either of the protocols studied in the trial as a good way to manage patients.

Importantly, Fry said, the lack of a clearly superior option “allows you to tailor the management of your patient at an individual level. You might think that the consequence of hypotension for your particular patient is greater than the consequence of hypertension. You might have another individual where you might think the consequence of hypertension is greater than the hypotension.”

Marcucci picked up a similar thread during the press briefing. “Since we know that the two options are both reasonable options, maybe we can listen more to what the patient wants,” she said, noting that “there are patients that are very attached to their chronic antihypertensive medication” and don’t want to stop taking them.