Large Variability in Use of Invasive Strategy for Type 1 NSTEMI: NCDR

The vast majority of patients presenting with type 1 NSTEMI undergo invasive coronary angiography in the US, with most receiving PCI, according to an analysis presented this week at CRT 2026. But as the study showed, there is considerable variability in the management approach across different sites.

The data also revealed a risk-treatment paradox: higher-risk patients were less likely to undergo invasive management even though that strategy was associated with better clinical outcomes, including a lower risk of in-hospital mortality, compared with conservative management,

The results, according to lead researcher Yasser Sammour, MD (Emory University, Atlanta, GA), suggest there’s an opportunity to improve the quality of care in patients with type 1 NSTEMI by standardizing risk stratification and treatment decisions.

“With STEMI, you have to urgently revascularize patients when they come, either as primary presentations or transfers,” said Sammour. “NSTEMI is a little bit different. If you think it is truly type 1 NSTEMI likely due to a culprit lesion, there is a heavy emphasis in the guidelines on invasive revascularization. But typically, it’s little bit different in that you do try to do some risk stratification, and it’s those in the high-risk groups who are usually the ones that benefit from revascularization.”  

Type 1 NSTEMI is caused by acute coronary atherothrombosis, usually the result of plaque rupture or erosion, and is often associated with partial or complete vessel blockage. In those who are at intermediate or high risk of ischemic events, US guidelines recommend that appropriate candidates are treated with an invasive strategy, with an eye toward revascularization, during the index hospitalization (class 1, level of evidence A). The guidelines also say it’s reasonable to go with the invasive strategy within the initial 24 hours of presentation (class 2a, level of evidence B-R).

A prior study from the National Cardiovascular Data Registry (NCDR) ACTION Registry published in 2018 showed there was wide variability when it came to the use of an early invasive strategy in patients presenting with NSTEMI. The new analysis, which was published simultaneously in Circulation: Cardiovascular Interventions, is a more contemporary look at practice patterns of 541 hospitals in the NCDR Chest Pain-MI Registry. The study included 287,275 patients (mean age 67.6 years; 36.4% women) with type 1 NSTEMI who presented between 2019 and 2024.

In all, 87.1% of patients underwent invasive coronary angiography. Of these, 66.1% received PCI and 11.5% underwent CABG surgery during the index hospitalization. The conservatively managed patients were older on average (75.5 vs 66.4 years) and more likely to be women (45.7% vs 35.0%) and to be Black or Hispanic. They were also more likely to have significant comorbidities, including heart failure, diabetes, PAD, atrial fibrillation/flutter, and cerebrovascular disease, and to need dialysis. Mean NCDR Chest Pain-MI risk scores were significantly higher in those treated conservatively.

Among those treated with the invasive approach, most (56.9%) underwent angiography within 24 hours of admission. Those treated with an early invasive strategy were younger on average, were more likely to be male and white, and had fewer comorbidities compared with those who underwent delayed angiography.

There was a wide degree of variability across the different sites opting for the invasive strategy. For example, the percentage of type 1 NSTEMI patients treated invasively at sites ranged from 57.3% to 100%. The median odds ratio (MOR), which quantifies hospital-level heterogeneity, for selecting an invasive strategy as opposed to conservative management was 2.85 (95% CI 2.64-3.10).

“It basically means that if two identical patients presented to different hospitals, if you present to the hospital with the higher propensity of performing invasive coronary angiography for type 1 NSTEMI, there is almost a threefold higher probability that you will get this treatment compared with presenting to the hospital with a lower propensity of using invasive management,” said Sammour.

Benefits Extend Across Risk Strata

The study also looked at variability in undergoing early versus delayed invasive management on weekends and holidays because a hospital’s commitment to the early strategy might be best seen during off hours, say researchers. Among those treated invasively, the variability for the early approach was also large (MOR 1.67), especially during off hours (MOR 1.89).

In a propensity-weighted analysis, the invasive strategy was associated with a 4.2% lower risk of in-hospital mortality (weighted OR 0.36; 95% CI 0.31-0.42) and 0.6% lower risk of stroke (weighted OR 0.58; 95% CI 0.48-0.70). There was, however, a 1.1% increased risk of bleeding in those treated invasively (weighted OR 1.50; 95% CI 1.29-1.75) but no difference in the need for new dialysis.

“We stratified patients across different risk categories and found that the association between the invasive management and [in-hospital] mortality was consistent across the different risk strata,” said Sammour.

As for the risk-treatment paradox, Sammour emphasized the guidelines recommend invasive management for these higher-risk patients, although he acknowledged that some hospitals might be worried about periprocedural risks in the sickest patients, which will deter them from proceeding with an invasive strategy.

“They may be worried about causing more harm,” said Sammour. The investigators say their results are very similar to data published decades ago that also showed the highest risk patients were less likely to undergo invasive angiography even though they stood to benefit most.

With the contemporary look, Sammour is hopeful hospitals will examine their own practice patterns to determine if type 1 NSTEMI patients are receiving appropriate, guideline-recommended care, particularly among the higher-risk patients. Additionally, he hopes these data spur programs to reduce the observed variability seen in centers. “At the community or national level, I think it would be helpful to have some initiative to help hospitals comply more with the national and international guidelines for the management of patients with ACS,” Sammour suggested.