May 16, 2023

Study Examines In-Hospital and Long-Term Outcomes of CTO PCI and High-Risk Non-CTO PCI

May 16, 2023—Using the American College of Cardiology National Cardiovascular Data Registry (NCDR) CathPCI Registry to compare patients undergoing chronic total occlusion (CTO) percutaneous coronary intervention (PCI) and non-CTO PCI, Almarzooq and colleagues found lower procedural success rates and higher adverse events during index hospitalization in the CTO PCI group, driven mainly by periprocedural myocardial infarction (MI) based on biomarker assessment, bleeding within 72 hours of the procedure, and intraprocedural and postprocedural cardiogenic shock. Differences were less apparent in CTO PCI patients versus high-risk non-CTO PCI and varied across high-risk non-CTO PCI subgroups. Results were published in Journal of the Society for Cardiovascular Angiography & Interventions.

KEY FINDINGS

Procedural success rates were lower and adverse event rates were higher during index hospitalization in the CTO PCI group as compared with the non-CTO PCI group.
CTO PCI was associated with a significantly lower procedural success rate as compared with high-risk non-CTO PCI but varied across all subgroups of high-risk non-CTO PCI.
Risk of the primary outcome was slightly higher in the CTO PCI group as compared with the non-CTO PCI group, mostly due to repeat revascularization.
However, CTO-PCI patients had a lower risk of the primary outcome when compared with high-risk non-CTO PCI, driven by postdischarge death and repeat revascularization.

Investigators aimed to compare in-hospital and long-term outcomes of CTO PCI versus outcomes of other high-risk non-CTO PCI procedures, including rotational atherectomy, unprotected left main (ULM) PCI, and saphenous vein graft (SVG) PCI.

Data from patients aged ≥ 65 years who underwent PCI from July 1, 2009, to December 31, 2016, were prospectively collected from the NCDR CathPCI Registry. Patients were excluded if they initially presented with ST-segment elevation MI, non–ST-segment elevation MI, preprocedure cardiogenic shock, or cardiac arrest. CTO PCI was classified as an index lesion with 100% thrombolysis in MI (TIMI) 0 flow and coded as CTO in the CathPCI Registry.

Demographic characteristics, prior medical history, and procedural and lesion characteristics were the covariates of interest, and in-hospital procedural events were evaluated. Procedural success was defined as < 50% stenosis on angiography with TIMI grade 3 flow after the procedure, with no major events, MI, cardiogenic shock, cardiac tamponade, new requirement for dialysis, other vascular complications requiring treatment, bleeding within 72 hours, and in-hospital mortality.

The primary outcome was major adverse cardiovascular events (MACE), defined as the composite of any cause death after discharge, repeat revascularization, and MI.

There were 1,990,847 patients who underwent PCI during the study period, and 551,722 (27.7%) were included for analysis; 29,407 (5.3%) underwent CTO PCI, and 53,662 (9.7%) underwent high-risk non-CTO PCI (21.6% included atherectomy, 9.0% included ULM PCI, 70.8% included SVG PCI). Patients in the CTO PCI group were more likely to be younger, male, and have a history of prior MI or coronary artery bypass graft.

Procedural success rates were significantly lower in the CTO PCI group versus the non-CTO PCI group (76.0% vs 96.1%; P < .001). CTO-PCI patients were more likely to have an in-hospital event postprocedure (7.0% vs 4.2%), largely influenced by biomarker-assessed periprocedural MI (3.4% vs 1.9%), bleeding within 72 hours (2.2% vs 1.3%); cardiogenic shock during and after the procedure (1.2% vs 0.3%), and in-hospital death (1.0% vs 0.4%) (all P < .001).

CTO PCI was associated with a significantly lower procedural success rate as compared with high-risk non-CTO PCI (76.0% vs 95.7%; P < .001), and this was consistent for all subgroups of high-risk non-CTO PCI. In-hospital events were slightly higher in the CTO PCI group versus high-risk non-CTO PCI (7.0% vs 6.5%; P = .008). For the high-risk non-CTO PCI subgroups, the risk remained higher when compared with non-CTO SVG PCI (7.0% vs 5.1%; P < .001), but was lower compared with non-CTO atherectomy PCI and non-CTO ULM PCI (7.0% and 9.1% vs 9.1% and 12.5%, respectively; both P < .001).

Patients in the CTO PCI group were slightly more likely to experience the primary outcome as compared with the non-CTO PCI group (49.9% vs 48.8%; P < .001), mostly due to repeat revascularization (24.4% vs 22.3%; P < .001). However, CTO-PCI patients had a lower risk when compared with high-risk non-CTO PCI (49.9% vs 63.9%; P < .001), driven by postdischarge death and repeat revascularization (27.8% vs 39.2% and 24.4% vs 31.3%; respectively; both P < .001).

Future studies should assess outcomes of CTO PCI with and without high-risk non-CTO PCI procedures to better understand their role in the procedural risk of CTO PCIs, noted the investigators.

CARDIAC INTERVENTIONS TODAY ASKS…

We asked study investigator Robert W. Yeh, MD, with Beth Israel Deaconess Medical Center in Boston, Massachusetts, about the study and how the results apply to practice.

How do the study’s findings inform clinical practice moving forward?

I think the study has several findings relevant for interventional cardiologists today. The first is that CTO PCI continues to be a more complex and difficult procedure, even with advances in technologies and procedural technique. However, compared to other complex PCI subsets, such as atherectomy and ULM PCI, CTO PCI can in fact be a lower-risk procedure for patients. Over the long term, the outcomes of CTO PCI are also on par or better than these other high-risk PCI procedures. I think they help demonstrate that CTO PCI falls well within the usual spectrum of risk that interventional cardiologists are accustomed to and should inform the way we discuss risks and benefits of these procedures.

What do the findings reveal about high-risk non-CTO PCI specifically with regard to approach in practice?

I think CTO PCI is often viewed as being a uniquely high-risk procedure for interventional cardiologists. However, we are routinely taking on procedures and patient subsets that are even higher risk. I think it is a reminder that proceduralists who do any complex coronary intervention, whether CTO, atherectomy, or left main PCI, need to have clear and honest discussions about the risks and benefits of the procedures with patients. There’s been a lot of scrutiny for CTO PCI specifically, but our data show that non-CTO complex PCI can be just as high or higher risk.

With lower procedural success and higher adverse event rates seen with both CTO-PCI and high-risk CTO-PCI in this study, what opportunities exist to help improve these outcomes in terms of training and other skill enhancement resources?

Most operators are not going to be CTO PCI experts in this country, but CTO techniques and devices allow interventionalists to really be much safer and more effective with all complex lesion subsets. I think there have been a series of courses that have tried to spread best practices for complex PCI to a less specialized audience, and we need to expand on these educational offerings.

What questions remain to be answered to better treat CTOs?

We still need strategies and devices to improve CTO PCI in a way that increases procedural success and reduces complications. And the elephant in the room remains—who are the patients who benefit most from CTO PCI and how much do they really benefit?

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