Compared with medical therapy alone or CABG, PCI of chronic total occlusions (CTOs) confers better long-term survival and other cardiovascular outcomes, suggest registry data published online September 2, 2015, ahead of print in the European Heart Journal.

The findings were first presented at TCT 2014 in Washington, DC.

Investigators led by Alfredo R. Galassi, MD, of Ospedale Cannizzaro (Catania, Italy), compared outcomes of 3 different management strategies used to treat 1,777 patients (mean age 68.6 years; 84.1% men) with 1,968 CTOs. All patients were enrolled in the prospective Italian Registry of Chronic Total Occlusions recruited from 12 high-volume centers between March 2008 and March 2009.

The occluded artery was most frequently the RCA (49.7%), followed by the LAD (28.8%) and the LCX (21.5%). Choice of management strategy was left to the local heart team; 46.5% of patients were treated with medical therapy, 43.7% with PCI, and 9.8% with CABG.   

Patients managed with medical therapy—which included beta-blockers, calcium channel blockers, nitrates, ACE inhibitors, angiotensin receptor blockers, and antianginal medications—were older and had more chronic renal failure than those treated percutaneously. A pathological Q wave on ECG was more often observed in patients who received medical therapy or CABG. On the other hand, LVEF and viable myocardium were more likely to be preserved in PCI patients than in those who received medical therapy or surgery. Optimal medical therapy was prescribed in 98.2% of medical therapy patients compared with 55% of the PCI group.

Higher likelihood of patients receiving a particular strategy was independently predicted by certain clinical and angiographic characteristics:

• Medical therapy: chronic renal failure, low LVEF, absence of viable myocardium in the CTO territory
• PCI: presence of bridge collateralization, viable myocardium, and the LAD as the culprit CTO artery
• CABG: the presence of more than 1 CTO, multivessel disease, and the absence of viable myocardium in the CTO territory

PCI Tied to Less MACCE, Cardiac Death

Successful PCI, defined as final residual stenosis < 30% with a TIMI flow grade 3 after stenting, was achieved in 75.4% of cases. At 1 year, patients managed with medical therapy or CABG had higher rates of MACCE and cardiac death than those treated with PCI, with the advantage over the other therapies seen irrespective of angiographic success (P < .001 for all comparisons). CABG patients had higher rates of stroke than those managed with medical therapy or PCI (P < .001 for both), while those receiving medical therapy showed higher rates of acute MI and rehospitalization than those treated with PCI or CABG (P < .05 for all; table 1).

Predictors of MACCE at 1 year were:

• Chronic renal failure (OR 3.22; 95% CI 2.0-5.2)
• Medical therapy or CABG (2.69; 95% CI 1.62-4.47)
• Age, per 10-year increase (OR 1.60; 95% CI 1.29-1.98)

Kaplan-Meier analysis showed that patients with successful PCI had better 1-year MACCE-free survival than those treated with other strategies (log-rank P < .001).

In a separate analysis, 619 patients each from the PCI and medical therapy groups were matched by propensity score.  Compared with those treated with PCI, patients managed with medical therapy had higher incidences of MACCE, death, acute MI, and rehospitalization but a similar stroke rate.

According to the authors, in the past most interventionalists tended to avoid CTO PCI. But recent progress in equipment and technique leading to higher success rates and reduced periprocedural complications has encouraged broader use of the intervention.

In a telephone interview with TCTMD, Emmanouil S. Brilakis, MD, PhD, of the Dallas VA Medical Center (Dallas, TX), said that operator skill still plays a role in the choice of CTO therapy, and since nearly half of patients in this all-comers registry received PCI, these clinicians must have felt comfortable offering the treatment. Even so, he noted, the success rate is considerably lower than what one would expect in contemporary practice.

PCI More Likely in Lower-Risk Patients

The current findings accord with those of a Canadian multicenter registry, in which low-risk patients were the most suitable candidates for CTO PCI, Dr. Galassi and colleagues say. “On the other hand, although patients with a low LVEF could… benefit from a functional complete revascularization, their fragility may suggest managing them conservatively by [medical therapy], especially in [the] absence of symptoms or viability. Furthermore, operators could be more reluctant to perform the cumbersome procedures in elderly patients with impaired renal function to avoid complications.”

Dr. Brilakis agreed. “You try to be more aggressive in patients who are better off to start with, whereas for those who are sicker and won’t do as well, you might be less likely to revascularize them,” he commented. “That’s a bias inherent in any [comparative] study like this.”

Other factors that influence CTO management have to do with the likelihood of success, Dr. Brilakis noted. For example, “if you don’t have good collaterals, your success rate goes down,” he said. In addition, CTO PCI is generally performed to improve symptoms, he noted, adding that “the younger and more active patients, the more likely they are to have symptoms, and that may make you more motivated to do PCI.”

Although the European and US guidelines both give CTO PCI a class IIa indication, the appropriate use criteria (AUC) range from appropriate to uncertain to inappropriate for different scenarios, Dr. Brilakis observed. Some argue that while the diverse ratings may make sense when the procedure is performed by less experienced interventionalists, for skilled operators, CTO PCI should be rated on the same appropriateness scale as PCI for other indications, he observed.

“The lack of available randomized trials that would address the question of whether successful CTO PCI improved survival in comparison with [medical therapy] is one of the main arguments against the expansion of CTO indication,” the authors say.

Dr. Brilakis said that the first randomized data, in this case in STEMI patients, will come from the EXPLORE trial, which is scheduled to be presented at the upcoming TCT meeting. However, enrollment has stalled in the DECISION-CTO trial, which is randomizing Korean patients with stable angina, Dr. Brilakis reported, adding, “It doesn’t look like we’ll have much randomized data anytime soon.”

Meanwhile, the current observational study suggests that “CTO PCI performed in unselected population seems to have very favorable outcomes,” he concluded.

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Source:  
Tomasello SD, Boukhris M, Giubilato S, et al. Management strategies in patients affected by chronic total occlusions: results from the Italian registry of chronic total occlusions. Eur Heart J. 2015;Epub ahead of print.

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