Unwarranted Stress Testing Before Knee, Hip Surgery Is Declining

(UPDATED) Cardiac stress testing is consistently on the decline among patients slated for hip or knee replacement, according to a cross-sectional study of data spanning a 14-year period, though people without known risk factors still represent a sizeable segment of those tested. Also important, researchers found, is that even higher-risk patients obtained no benefit from screening.

In the early 2000s, an uptick in cardiac imaging led to concerns about healthcare costs and potential overuse. Both the 2007 and 2014 American College of Cardiology/American Heart Association (ACC/AHA) “guidelines have consistently de-emphasized preoperative cardiac testing prompted solely by the upcoming surgery in the absence of signs or symptoms that would warrant testing outside of the preoperative setting,” Daniel S. Rubin, MD (University of Chicago, IL), and colleagues note in their paper published recently in JAMA Cardiology.

“Additionally, over the last two decades, there has been an increased national focus on potential overuse of cardiac testing,” they write. “Appropriate use criteria, prior authorization requirements from third-party payers, and medical society initiatives, such as the Choosing Wisely campaign, have attempted to optimize use and decrease unnecessary cardiovascular stress testing.

Based on what they found in their analysis, Rubin told TCTMD, “cardiologists aren’t stressing as many people as they used to. What’s interesting is that it’s more likely than not due to secular trends in stress testing as opposed to the implementation of the guidelines.”

Rubin said he’d expected there to be a stronger link between shifting guidelines than what the study observed. Compared to its 2002 predecessor, the 2007 document’s approach to risk stratification was a “vast simplification . . . and made it a lot easier for clinicians to use,” he commented. Instead, their study found the downward trend in use started in late 2006.

William Zoghbi, MD (Houston Methodist DeBakey Heart & Vascular Center, TX), agreed that things are moving in the right direction. For one, adverse event rates seem to be going down, suggesting “medicine has improved.” Also, he continued, “there is more appropriate use of stress testing prior to knee or hip surgeries over time.”

Zoghbi, too, credited the Choosing Wisely campaign, a multisociety effort spearheaded by the American Board of Internal Medicine, for creating more awareness. In part, this is because the messaging was directed “not only to physicians and healthcare providers but to the patients.”

“I think some of these messages take time to trickle [down],” said Zoghbi, who was ACC’s president when the campaign debuted in 2012. Gradually, the idea that stress tests aren’t always mandatory “is coming to fruition,” he added. “We still have a long way to go, but I like the trends.”

MACE Rates Similar

For their analysis, Rubin et al delved into the IBM MarketScan Research Databases to obtain inpatient and outpatient healthcare claims for private insurers, including supplemental Medicare coverage. Their study included 801,396 individuals (median age 62 years; 58.1% women) who underwent elective total hip (27.9%) or knee arthroplasty (72.1%) between 2004 and 2017.

Patients who had preoperative testing within 2 months prior to surgery tended to be older (median 66 vs 62 years) and were more likely to be male (45.8% vs 41.5%; P < 0.001 for both). Stress tests also were less commonly given to patients enrolled in a capitated insurance plan than if they were in a noncapitated plan.

Current ACC/AHA guidelines gauge the need for preoperative testing based on the Revised Cardiac Risk Index (RCRI), which lists five conditions: ischemic heart disease, heart failure, insulin therapy for diabetes, cerebrovascular disease, and chronic kidney disease. They “specify that no patient with zero RCRI conditions warrants preoperative stress testing prior to an intermediate-risk surgery, such as total hip or knee arthroplasty, even those with poor functional status,” the researchers say.

Still, in the current study, nearly half (49%) of those tested had zero RCRI conditions. This segment of low-risk patients increased from 44.7% in 2004 to 52.6% in 2017 (P < 0.001).

One should not do a stress test specifically because you’re going to have a ‘stressful’ surgical procedure coming up. That’s not the indication for it. Daniel Rubin

Across the entire time period, the stress testing rate in the 2 months prior to surgery was 10.4%, increasing 0.65% annually from 2004 until the second quarter of 2006. At this time, there was a “clear inflection point”—stress testing use began to decrease annually by 0.71% until the latter part of 2013, when the decline slowed to 0.40%.

“The reason for this decline is likely multifactorial because it occurred with a national focus on use and costs, with a shift to the value-based healthcare era,” the investigators propose, adding that the ACC/AHA guidelines may have contributed, as well. “However, we did not find a meaningful change in the number of stress tests performed in patients with zero RCRI risk factors, those patients for whom preoperative stress testing was specifically discouraged by the new guidelines. This finding suggests limited adherence to the guidelines and an opportunity for further reductions in preoperative stress testing.”

The combined in-hospital rate of MI/cardiac arrest was 0.24%. In the no-RCRI group, people who underwent stress testing had more of these adverse events than without such testing (0.27% vs 0.14%; P < 0.001).

Among patients with at least one RCRI condition, the rate didn’t differ based on the use of preoperative stress testing or the lack thereof (0.60% vs 0.57%: P = 0.51), “which suggests stress testing may not contribute to risk stratification in this patient population,” the authors conclude.

Rubin, pointing to the higher event rate with testing among no-RCRI patients, said this may suggest something positive, in that “clinicians do have a sense within them who is high risk and who is not that comes outside of our standardized risk-stratification technique.”

For him, the overarching question is whether stress testing will actually change a patient’s treatment course and outcomes. “I think generally speaking we still recommend that if you are going to do a stress test completely independent of the perioperative period—meaning, for indications outside of the fact that they’re going to have surgery—it seems reasonable,” Rubin said. “But one should not do a stress test specifically because you’re going to have a ‘stressful’ surgical procedure coming up. That’s not the indication for it.”And while this study’s results can’t be directly applied to stress testing prior to other types of surgeries beyond elective total hip/knee arthroplasty, he added, the above message “still rings true."

We still have a long way to go, but I like the trends. William Zoghbi

Zoghbi also emphasized a clear takeaway: “If you’re overall well and there are no indicators for increased cardiovascular risk and you have less-risky surgery, you don’t really need the major testing that we [can] do. Because number one, it may be normal. Number two, it won’t change management.”

The fact that so many stress tests were done in patients with no risk factors may come down to “habit,” said Zoghbi. “At times there is this fear from a physician’s point of view of risk. Yet the clinical indicators tell us that if you don’t have high-risk [features] the outcome is good overall and though it may not be guaranteed—because some of these patients had MACE, right?—it is not [riskier] than if you do testing.”