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PCI, optimal medical therapy yield similar outcomes in DECISION-CTO trial
WASHINGTON — In the first randomized clinical trial to compare optimal medical therapy alone with PCI in patients with a coronary chronic total occlusion, the therapeutic strategy was noninferior to intervention for the primary endpoint of death, MI, stroke or any revascularization at 3 years.
The rate of the primary endpoint at 3 years in the intention-to-treat population of patients with a CTO was 19.6% in the optimal medical therapy group vs. 20.6% in the PCI group (P for noninferiority = .008). Measures of health-related quality of life, assessed by the Seattle Angina Questionnaire, were comparable during follow-up between the two groups.
“This study suggests that optimal medical therapy could be a reasonable initial treatment strategy for coronary CTO compared with CTO PCI. Further randomized clinical trials are necessary,” Seung-Jung Park, MD, PhD, from the Heart Institute at University of Ulsan College of Medicine Asan Medical Center, Seoul, Korea, said during a presentation.
The prospective, open-label, randomized trial was conducted at 19 sites in India, Indonesia, Korea and Thailand. The researchers randomly assigned 834 patients to undergo PCI with a drug-eluting stent plus optimal medical therapy (n = 417) and 398 to optimal medical therapy alone (n = 398). Guideline-derived optimal medical therapy included aspirin, P2Y12 receptor inhibitors, beta-blockers, calcium channel blockers, nitrates, ACE inhibitors/angiotensin receptor blockers and statins; BP and diabetic control, smoking cessation, weight control and regular exercise were also recommended. In cases of failed CTO PCI, additional attempts were allowed within 30 days after the index procedure. Use of devices and techniques were left to the operator’s discretion.
“Because enrollment was slower than anticipated, enrollment was stopped in September 2016, as recommended by the data and safety monitoring board, by which time 834 patients had been enrolled. The sponsor and study leadership were unaware of study results at the time of this decision,” Park said.
He noted that interventional cardiologists may have been reluctant to enroll patients because of the predominant view that blocked arteries should be opened.
Among those enrolled, the mean age was 62 years and most were male (> 80%). Nearly three-quarters of patients in both groups had stable angina and multivessel disease. CTOs were primarily located in the right coronary artery or left anterior descending artery. Mean SYNTAX score was 21.
Overall CTO PCI success was 91%. Most patients received two stents. The retrograde approach was used in one-quarter and the single wire CTO technique in 74%. More than half of patients required additional back-up support using a microcatheter other than the Corsair (Asahi Intecc).
Park also presented results of additional analyses comparing PCI vs. optimal medical therapy. “However, optimal medical therapy did not meet the statistical criteria for noninferiority compared with PCI in the predefined per-protocol and as-treated population-based analyses, although event rates were not significantly different between groups at 3 years,” he said.
In the per-protocol analysis, the estimated 3-year rate of the primary endpoint was 22.3% in the optimal medical therapy group vs. 19% in the PCI group (P for noninferiority = .15; event rate ratio [RR] = 0.86). In the as-treated analysis, the estimated 3-year rate was 19.6% in the optimal medical therapy group vs. 20.6% in the PCI group (P for noninferiority = .008).
The DECISION-CTO researchers also analyzed outcomes through 5 years and found no difference in the rate of the primary endpoint (PCI, 26.3% vs. optimal medical therapy, 25.1%; crude HR = 0.95; 95% CI, 0.74-1.22; adjusted HR = 0.91; 95% CI, 0.68-1.23) or individual components of the endpoint.
During a discussion of the trial, David Kandzari, MD, director of interventional cardiology and chief scientific officer of the Piedmont Heart Institute, Atlanta, said “the DECISION-CTO trial represents an ambitious undertaking, in part because CTOs are the most complex lesion in interventional cardiology and operator experience is highly dependent on the procedural outcome, which, of course, is highly variable.” Further, he noted that “preconceived opinion, often from physician experience of anecdote, can influence treatment recommendations or even avoidance for inclusion into a clinical trial.”
Kandzari likened DECISION-CTO to the COURAGE trial, based on its design, conduct, endpoints and outcome.
“We should also be reminded of the likelihood for substantial crossover to revascularization, which occurred in more than 20% of patients, despite randomization to medical therapy alone, and this is not represented in the conclusion of noninferiority nor is the likelihood of about 10% of the patients randomized to medical therapy alone not undergoing any attempted revascularization,” Kandzari said.
“Indeed, as Dr. Park showed, the event rates vary according to the analytical method. … Perhaps too, like the COURAGE trial then, a strategy of initial medical therapy compared with revascularization certainly may be reasonable. But, it is important to acknowledge that crossover to revascularization, as in real-world clinical practice, may be clinically prudent in a number of patients. The DECISION-CTO trial might be, therefore, perhaps considered as a strategy trial of intensified additional medical therapy in stable patients with angina and CTO, rather than one of finality and wholly discounting the clinical merits of CTO revascularization,” he said. – by Katie Kalvaitis
Reference:
Park SJ, et al. Late-Breaking Clinical Trials: Interventional. Presented at: American College of Cardiology Scientific Session; March 17-19, 2017; Washington, D.C.
Disclosure: Park reports receiving consultant fees/honoraria from Abbott, Boston Scientific, Cordis and Medtronic. Kandzari reports receiving consultant fees/honoraria from Boston Scientific, Medtronic and St. Jude Medical.
Perspective
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In my opinion DECISION-CTO will have limited impact on contemporary practice for the following reasons:
One, the study design had major design flaws. Most patients enrolled had non-CTO CAD, and it is unclear how many patients had symptoms and/or ischemia after revascularization of the non-CTO lesions. The lack of difference in symptoms in the CTO PCI group may suggest that patients did not have significant symptoms after non-CTO revascularization.
Two, it is unclear whether that myocardial territories supplied by the CTO were viable. Revascularization of non-viable territories would be unlikely to improve clinical outcomes.
Three, the crossover from the optimal medical therapy arm to the CTO PCI arm is very large: 18%, or almost 1 in 5 patients. Therefore, any potential benefits of CTO PCI would be diluted.
Four, the early termination of the enrollment and follow-up limits the power of the study.
Although it is good that this study was conducted, because we don’t have enough trials in this space, the way it was done makes it very hard to draw any conclusions because of the design and the crossover issues. It is also surprising that in the PCI group there was no benefit whatsoever in terms of quality of life, which is counter to everything we’ve seen so far in terms of PCI improving quality of life for people with stable CAD. CTO PCI is done in most patients for treating symptoms, usually angina and dyspnea. Hence, the patients that should be studied are patients with significant symptoms and the primary endpoint should be related to patient quality of life.