NO BENEFIT OF STENT FOR STABLE CAD

Respected investigators from Imperial College London have shaken the core of cardiology. The stakes could not be bigger. Millions of people have received stents for stable coronary artery disease (CAD) at a cost of billions of dollars.

The ORBITA^[1] trialists, who presented their findings at TCT 2017, tested the last holdout for PCI in stable patients—relief of angina. Never before has PCI been subjected to the best test for any medical procedure—a sham control.^[2,3] Angina is subjective, and subjective symptoms are susceptible to placebo and nocebo effects.^[3,4]

It's important to set out that this discussion deals with the use of PCI in patients with stable disease—it does not address acute ischemic conditions where PCI delivers dramatic benefits.

ORBITA Background

In 2007, findings from the randomized controlled COURAGE^[5] trial also shocked the cardiology community when it showed that PCI in addition to optimal medical therapy (OMT) did not reduce the rate of MI or death compared with OMT alone in patients with stable CAD. These findings have persisted through 15 years of follow-up.^[6]

Via email, the primary investigator of COURAGE, Dr William Boden (Boston University, MA), highlighted that investigators found no subset of patients that did better with PCI vs OMT. Not those with multivessel disease and EF<50 and="" disease="" ischemia.="" lad="" moderate-severe="" not="" nuclear="" showing="" studies="" style="font-size: 0.75em; line-height: 1; max-width: 100%;" sup="" those="" with="">[7–9]

Interventional cardiologists hold that PCI delivered angina relief, but that case rests on shaky evidence. In the unblinded COURAGE trial, the small benefit in angina in the PCI arm waned at 3 years.^[10] Some experts argue this was due to crossover PCI in the OMT group.

Boden believes the crossover issue is overstated, since a large percentage of crossover occurred in the first year of COURAGE. A substudy of COURAGE^[11]looked specifically at outcomes of patients in the OMT group who crossed over to PCI and found no difference in end points when compared with those in the PCI group. The authors concluded that "because early crossover was not associated with an increase in irreversible ischemic events or impaired 12-month health status, these findings support an initial trial of OMT in stable ischemic heart disease with close follow-up of the most symptomatic patients."

ORBITA Findings 

Patrice Wendling has an excellent news summary of the ORBITA trial. Compared with the sham-controlled group,

• PCI did not significantly improve exercise time. The numerical incremental increase in average exercise time was 16 seconds (P=0.20).
• PCI did not significantly improve measures on well-validated patient-centered angina questionnaires.
• PCI did not significantly improve the Duke treadmill score or peak oxygen uptake.
• PCI did significantly improve the dobutamine stress echo wall-motion index, indicating that stenting reduced ischemic burden.