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EXCEL: Left Main Stenting Holding Up to CABG at 5 Years

— The trial held a mortality surprise, though

Last Updated September 30, 2019
MedpageToday

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SAN FRANCISCO -- For lower surgical risk patients with left main coronary artery disease, stenting remained on par with coronary artery graft surgery (CABG) at 5 years in the EXCEL trial.

At that final analysis, percutaneous coronary intervention (PCI) had a composite rate of 22.0% for death, stroke, or MI compared with 19.2% for the surgical group (P=0.13), found Gregg Stone, MD, of Icahn School of Medicine at Mount Sinai in New York City and director of Transcatheter Cardiovascular Therapeutics (TCT), and colleagues.

The curves crossed over at about 36 months, Stone reported at the TCT annual meeting and online in the.

Hazard ratios for the primary outcome grew across that period from favoring PCI at 30 days (0.61, 95% CI 0.42-0.88) to favoring CABG at 30 days to 1 year (1.07, 95% CI 0.68-1.70) and at year 1 to 5 (1.61, 95% CI 1.23-2.12).

"The crossing of the curves is what we see in almost every study we do comparing an invasive procedure to a noninvasive procedure," commented Kenneth Ouriel, MD, a vascular surgeon working for clinical research organization Syntactx in New York City, who was part of the discussion panel at a TCT press conference.

While the overall finding matched the previously reported 3-year results, the difference in all-cause mortality gained statistical significance, favoring CABG (9.9% vs 13.0%).

Not surprisingly, ischemia-driven revascularization was significantly more common after PCI than after CABG at 5 years (16.9% vs 10.0%) and typically represented repeat PCI.

PCI had numerically more definite cardiovascular deaths (5.0% vs 4.5%) and MIs (10.6% vs 9.1%) as well, although nonsignificantly fewer cerebrovascular events (3.3% vs 5.2%) and strokes (2.9% vs 3.7%).

"Although some of these findings may indicate true treatment effects, they must be interpreted cautiously, since more than 20 secondary outcomes were assessed and analyses were not adjusted for multiple comparisons," Stone's group wrote.

The bulk of the difference in all-cause mortality was made up by cancer, late infections, and late sepsis unrelated to the procedure, Stone emphasized at a TCT press conference for the late-breaking clinical trial session.

The paper pointed to no excess of all-cause mortality after PCI at 5 years in the Nordic-Baltic-British Left Main Revascularization (NOBLE) trial, in meta-analyses, and at 10 years in the SYNTAX trial.

Altogether, the findings can help inform discussions between the heart team and the patient in weighing treatment strategy, concluded Robert Yeh, MD, of Beth Israel Deaconess Medical Center in Boston, at the session.

"Some patients may prioritize the ability to get back to work quickly and the avoidance of procedural morbidity," Yeh told ľֱ. "Others may be willing to undergo a more difficult course in the short term in order to have a more durable long term result. The EXCEL results support the idea that we can offer both treatments to trial-like patients with left main disease and allow them to choose based on how they weigh the various advantages and disadvantages of each."

EXCEL randomized 1,905 patients, largely in Europe and North America, to Xience drug-eluting stents or CABG. Participants had low or intermediate anatomical complexity at baseline, with site-reported SYNTAX scores no greater than 32.

Limitations included potential bias in event ascertainment given the open-label design; off-protocol enrollment of high SYNTAX score patients as about 25% of the cohort based on the core laboratory analysis; and differences in medication used during follow-up between the two arms.

"Finally, follow-up was limited to 5 years, and at this time point the hazard curves were continuing to diverge. Ten-year (or longer) follow-up is needed to characterize the very late safety profiles of PCI and CABG, since both stents and bypass grafts progressively fail over time," the researchers stated.

However, Stone noted that they are not funded to continue any longer term follow-up.

Disclosures

The trial was funded by Abbott Vascular.

Stone disclosed relevant relationships with Abbott, Terumo, Amaranth, Shockwave, Valfix, TherOx, Reva, Vascular Dynamics, Robocath, HeartFlow, Gore, Ablative Solutions, Matrizyme, Miracor, Neovasc, V-wave, Abiomed, Claret, Sirtex, Ancora, Qool Therapeutics, Cagent, Applied Therapeutics, the Biostar family of funds, the MedFocus family of funds, SpectraWave, MAIA Pharmaceuticals, Orchestra BioMed, and Aria. His employer, Columbia University, receives royalties from Abbott for sale of the MitraClip.

Ouriel disclosed being employed by, and holding equity in, Syntactx, which receives fees from Bard.

Primary Source

New England Journal of Medicine

Stone GW, et al "Five-Year Outcomes after PCI or CABG for Left Main Coronary Disease (EXCEL)" N Engl J Med 2019; DOI: 10.1056/NEJMoa1909406.