Aging, Angina, and Invasive Management: Some Nuance From ISCHEMIA

Older patients enrolled in the ISCHEMIA trial saw their angina symptoms improve with an invasive strategy as compared with more-conservative management, but unlike younger patients in the trial, they did not report the same improvements in overall health status, according to a new analysis.

As with the overall trial, older patients did not have any improvement in hard clinical outcomes with an invasive approach, Dan Nguyen, MD (Saint Luke’s Mid America Heart Institute, Kansas City, MO), and colleagues report in the Journal of the American College of Cardiology.

Older adults represent the fastest growing population of patients in the United States, and stable ischemic heart disease is extremely common in this subset, Nguyen observed. Understanding how the ISCHEMIA results apply in this group is “critically important,” he told TCTMD.

“Older adults,” said Nguyen, “value their health status, their symptoms, their physical function, and their quality of life, so the decision to pursue a more-invasive treatment strategy may be something of particular interest to older adults, especially to improve their function and quality of life.”

Doing so, however, entails higher risks than those faced by the overall ISCHEMIA cohort. “We know from prior observational research that the risks of pursuing revascularization are much higher in older adults. Older adults have a greater risk of acute kidney injury, of major bleeding, and that risk has to be offset with the health status improvement,” he explained. “I think the importance of this paper is that it shows that older adults actually can get some improvements in their health status, but it might not be as much as we thought and that has to be taken into consideration when we decide to refer older adults to invasive management.”

That decision, he added, “needs to be a little bit more nuanced.”

Older Adults in ISCHEMIA

ISCHEMIA enrolled a total of 5,179 patients, but just 4,617 patients had full health status information suited to the current analysis. Of these, 1,713 (37.1%) were aged 65 to 74 years and 665 (14.4%) were aged 75 years or older, a “substantially larger” number of older adults than prior randomized trials had included.

Of note, while rates of cardiac catheterization in those randomized to invasive care were roughly similar for patients age 75 and older and younger patients, the older group was less likely to proceed to revascularization (69.8%) than patients under age 65 (83.6%) or age 65 to 74 (81.0%). But while reasons for not proceeding with revascularization in younger patients was typically the finding of nonobstructive disease on imaging, most often the reason in older patients was unsuitable coronary anatomy for either PCI or surgery.

Health status outcomes in ISCHEMIA were measured using the Seattle Angina Questionnaire (SAQ) before randomization, then at regular intervals through 78 months. For this analysis, investigators zeroed in on SAQ scores at 12 months, “as this represents a clinically relevant time frame for shared decision-making with patients,” they say. The score itself captures angina frequency, angina effects on physical functioning, and angina-related quality of life over the prior 4 weeks.

As Nguyen et al report, angina frequency was reduced to a similar extent across the different age groups, but overall changes in SAQ scores varied. In the youngest patients (55 or younger), the difference in scores between invasively versus conservatively managed patients was 4.90, but that number shrank to 3.48 at age 65, and 2.13 at age 75 (P for interaction = 0.008).

Asked about the apparent disconnect between the reported reductions in angina frequency and the lack of an impact on angina-related health status, Nguyen said that there are a number of possible explanations. Younger patients had lower SAQ scores to begin with, so more room for improvement. Older patients, by contrast, may not be engaging in as much physical activity as their younger counterparts, such that their angina is not as limiting of daily functions.

But those distinctions are the kind of thing that need to be captured in shared decision-making conversations with patients, he stressed.

“I think that's what the message of this paper is: for older adults, we need to be thoughtful before referring them straight to catheterization because some older adults may derive less improvements in their health status and quality of life than younger patients with revascularization as compared with medical therapy. I think the conversation has to start with not only the risks and benefits of treatment, but it also has to start with what the expected improvement is with invasive management,” he said. “We can say that for a particular older adult that their angina frequency will improve to the same extent as a young person, but they may not actually get the same benefits in terms of improvement in physical functioning and in quality of life.”

In an accompanying editorial, Parag Goyal, MD (Weill Cornell Medicine, New York, NY), and Michael G. Nanna, MD (Yale School of Medicine, New Haven, CT), call Nguyen et al’s study “a landmark contribution to the existing literature.”

Considering all of the findings from this study to date, they say, “data from the ISCHEMIA trial indicate that an invasive strategy in older adults with stable CAD can reduce future spontaneous MI and angina frequency but does not have a substantial impact on quality of life. Results here are critical to further informing the risk-benefit calculus of management decisions in older adults presenting with stable coronary disease, in which benefits must be balanced against upfront procedural risks and risk for complications such as bleeding or acute renal injury.”