DENVER, CO — Routine PCI of chronic total occlusions (CTO) does not lead to improved left ventricular function, whether regional or global by MRI, compared with a strategy of discretionary PCI that avoids CTOs, suggests a small study[1].
The European trial randomized only patients with symptoms or positive stress tests on optimal medical therapy (OMT) who had angiographically confirmed CTOs, during an era when there was more equipoise about whether routine PCI of CTOs would protect myocardium and reduce the risk of future events.
The study included 101 patients randomized to mandated PCI of all CTOs with an option to have other lesions treated throughout the coronaries, but in practice operators tended to aim for complete revascularization, Dr Kambis Mashayekhi (University Heart Center Freiburg-Bad Krozingen, Germany) told theheart.org | Medscape Cardiology.
The other 104 patients, he noted, were randomized to get PCI or no PCI at the operators’ discretion, but if PCI was chosen, the previously identified CTOs were avoided.
The two groups did not differ significantly in the primary end point of percentage of change in segmental wall thickening in myocardial segments associated with the CTOs, by cardiac MRI conducted at baseline and at 12 months. Nor were there significant differences in change in LVEF or LV end-diastolic volume (LVEDV).
Nor, as it turned out post hoc, were there significant differences between the groups when the MRI-defined primary end point was limited to myocardial segments that were dysfunctional at baseline.
Mashayekhi, who presented the results of the Recovery of Left Ventricular Function in Chronic Total Occluded Coronary Arteries (REVASC) study here at TCT 2017, pointed out that it has since been appreciated that myocardium under a treated CTO can take 6 to 12 months to show functional improvement, if it improves at all.
Today, he acknowledged, few operators at the time of PCI would comprehensively treat CTOs at the same session but rather would reserve it for lesions later found to be associated with viable myocardium. That usually means staging any PCI for CTO after conducting tests for likely ischemia in those segments.
“It’s better to do CTOs when the involved myocardium has clear evidence of hypoperfusion or ischemia and clear segmental wall thickening. Now, those people benefit from CTO revascularization,” Mashayekhi said in an interview.
It would also be best to refer such patients for PCI on clinically important CTOs to centers experienced in treatment of such lesions, he said, as complications from it are “overrepresented” at less experienced centers.
Still, randomized trials are needed to determine whether even such late CTO revascularization in patients with multivessel disease is called for, Mashayekhi noted.
Prior recent studies of CTO revascularization have found either parity with OMT or benefits to PCI of CTOs with a greater dependent swath of myocardium, or other conflicting results. Often, however, those trials have been small and underpowered, or with other limitations that kept them far from definitive.
“I think this [REVASC] data support the concept of being able to use optimal medical therapy until you deem that it has maybe failed,” Dr Wayne B Batchelor (Florida State University, Tallahassee) told theheart.org | Medscape Cardiology.
“And there’s no downside that I can see in adopting that strategy now: revascularizing what you can and leaving the CTOs behind. I haven’t seen data to suggest that you have to do [PCI on CTOs] up front,” he said.
Mashayekhi had pointed out that baseline LVEF in the non-CTO-PCI group averaged 59.6% and in the CTO-PC group the mean was 54.7%—that is, patients tended to have preserved rather than impaired ventricular function at the outset.
That could explain the lack of significant wall-motion improvement, he acknowledged. And it led Dr J Aaron Grantham (Saint Luke’s Mid America Heart Institute, Kansas City, MO), during the panelist critique following the trial’s formal presentation, to reiterate, “If you want to improve LV function in patients with CTOs, don’t start with patients who have normal LV function.”
Moreover, the trial also excluded patients with severely impaired ventricular function (ie, an LVEF <25%) and those with ACS within the previous 72 hours.
Also of note, about one-third of patients in the discretionary-PCI group did not undergo PCI; rather, OMT was judged the best therapy for the time being, leaving only about 65% of the arm to have PCI that avoided CTOs.
In one of the trial’s findings that on the surface seems positive for CTO revascularization: the 12-month rate of major adverse cardiac events (MACE)—defined as death from any cause, MI, or clinically driven repeat revascularization—was 18.2% in the non-CTO-PCI group but only 5.9% in the CTO-PCI group (P=0.02).
That result, driven almost entirely by repeat revascularization, is not to be taken too seriously despite the P value, Mashayekhi said when interviewed, as the trial was grossly underpowered for clinical events.
REVASC was sponsored by Cordis. Mashayekhi discloses receiving consulting fees or honoraria from Ashai Intecc, Vascular Solutions, Cordis, Abbott, Biotronik, Terumo, AstraZeneca, and Daiichi Sankyo. Batchelor discloses having a financial interest or affiliation with Boston Scientific, Abbott Vascular, and Medtronic. Grantham discloses receiving research support or consulting fees or honoraria, holding equity ownership, or receiving salary from Boston Scientific, Abbott Vascular, Vascular Solutions, St Jude Medical, Asahi-Intecc, Corindus, and Insysiv.
Follow Steve Stiles on Twitter: @SteveStiles2. For more from theheart.org | Medscape Cardiology, follow us on Twitter and Facebook.
Tidak ada komentar:
Posting Komentar