Multinational CTO Registry Reports Long-Term PCI Outcomes

June 24, 2013—In Catheterization and Cardiovascular Interventions, two studies were published that evaluated outcomes after percutaneous coronary intervention (PCI) for chronic total occlusions (CTO) in the Multinational CTO Registry, which was composed of 1,791 patients who underwent PCI for a CTO between 1998 and 2007 at three tertiary care centers in the United States, Italy, and South Korea.

In the first study in Catheterization and Cardiovascular Interventions, Loes P. Hoebers, MD, et al published an evaluation of the procedural success rates and long-term clinical outcomes of PCI CTO in elderly patients, of which little is known (2013;82:85–92).

As summarized in the study's abstract, for the registry's 1,791 consecutive patients, there were 1,852 CTO treated with PCI at three large centers in the United States, Italy, and South Korea. The registry included 213 patients (12%) aged 75 or older.

Outcomes included procedural success and major adverse cardiac events (MACE, a composite of mortality, myocardial infarction, or coronary artery bypass graft surgery [CABG]). Time-to-event analyses were performed using Kaplan-Meier statistics, and the log-rank statistic was used to test for differences between patients aged 75 or older and patients younger than 75 years.

The investigators reported that procedural success rates were similar in elderly patients compared with patients younger than 75 years (63.8% vs 69.1%; P = .12). Median follow-up was 890 days (IQR: 380–1,480 days). MACE rates after successful versus failed PCI were 25.8% versus 42.3% in the elderly (P = .02) and 11.2% versus 20.8% in younger patients (P < .01). In elderly patients, this reduction in MACE after successful PCI was mainly driven by a reduction in CABG (0% vs 20.4%; P < .01). There were no significant differences in terms of mortality (19.6% vs 24.6%; P = .13) or myocardial infarction (11.5% vs 8%; P = .87).

The investigators concluded that CTO PCI in patients aged 75 years or older has similar success as in patients younger than 75 years. In elderly patients undergoing CTO PCI, MACE rates were relatively high, but successful revascularization is associated with a reduction in MACE at 5-year follow-up in both elderly and younger patients, stated the investigators in Catheterization and Cardiovascular Interventions.

In the second study in Catheterization and Cardiovascular Interventions, Bimmer E. Claessen, MD, et al evaluated the impact of the target vessel on long-term survival after CTO PCI (2013;82:76–82). This study sought to investigate whether there is a differential prognostic effect of successful PCI of CTO according to the target vessel in which the CTO is located.

In this analysis, of the 1,791 patients in the registry, patients with CTOs in multiple target vessels or the left main stem were excluded (n = 57). Of the remaining 1,734 patients, 609 had a CTO in the left anterior descending artery (LAD, 35.1%), 391 in the left circumflex artery (LCX, 22.5%), and 734 in the right coronary artery (RCA, 42.3%). Five-year mortality and the need for CABG were compared between patients with successful versus unsuccessful PCI stratified by target vessel.

The investigators reported that procedural success was obtained in 71.1% of LAD patients, 69.1% of LCX patients, and 65.1% of RCA patients (P = .06). The mean follow-up duration was 1,178 days. Kaplan-Meier estimates of long-term mortality were 6.7% versus 11% (P = .03); 5.5% versus 13.9% (P < .01) and 6.6% versus 4.1% (P = .8) in successful versus unsuccessful procedures in LAD, LCX, and RCA patients, respectively.

After multivariate analysis, successful CTO PCI remained associated with lower mortality in the LAD group (HR .41; P = .02) and LCX group (HR .32; P < .01). The need for CABG was lower after successful CTO PCI in all three groups (LAD, 4.6% vs 16%; P < .01; LCX, 2.9% vs 18.2%; P < .01; RCA, 2.3% vs 8.4%; P < .01).

These results from this large contemporary cohort of patients suggest that successful PCI of a CTO in the LAD and the LCX, but not the RCA, is associated with improved long-term survival, concluded the investigators in Catheterization and Cardiovascular Interventions.