Short-term Outcomes Worse After Failed CTO PCI
Failed chronic total occlusion (CTO) PCIs are associated with more procedural complications and poorer short-term clinical outcomes compared with successful procedures, according to a meta-analysis published online December 4, 2014, in Catheterization and Cardiovascular Interventions. However, rates of adverse outcomes have declined over the past few decades for both successful and failed cases.
“We have evidence that successful CTO PCI results in improved long-term outcomes…,” Muhammad F. Khan, MD, of the Southern Arizona VA Health Care System (Tucson, AZ), and colleagues write. “Therefore, patient selection for percutaneous CTO intervention should be individualized based on the risks of complications (probability of failed intervention) versus the benefits of improved long-term outcomes (in case of successful PCI).”
Careful assessment of lesion morphology and other factors along with the operator’s ability to deal with CTOs is paramount before embarking on the procedure, they add.
The researchers performed a meta-analysis of 25 studies that included a total of 16,490 patients and were published from 1991 through 2013. Overall, 75% had successful and 25% failed CTO PCI. The most common reasons for failure were an inability to cross the lesion with a guidewire and subsequent failure to cross the lesion or dilate it with a balloon.
Compared with successful CTO PCI, failure was associated with higher rates of in-hospital MACE (mortality, MI, and TVR), mortality, MI, and need for urgent CABG (table 1).
Failed procedures also came with higher rates of some periprocedural complications, including coronary perforation (7.4% vs 1.9%; RR 5.09; 95% CI 3.93-6.59) and cardiac tamponade (1.16% vs 0.22%; RR 5.00; 95% CI 1.97-12.69). Those differences largely explain the increase in mortality after failed CTO PCI, the authors say.
Rates of all adverse clinical outcomes declined over time in both groups. For example, the rate of in-hospital death for failed PCI decreased from 2.5% in 1980-1995 (an era of angioplasty alone) to 0.8% in 2008-2010 (an era characterized by use of the modified retrograde approach and new technologies), while that for successful PCI dropped from 0.7% to 0.1%, respectively.
Absolute Risk Difference Small
Dr. Khan and colleagues note that even though failed procedures were associated with greater risks of adverse outcomes and complications, the absolute differences were not that large—less than 1 per 100 procedures, “which, in fact, is quite reassuring.”
They calculated that the number of failed procedures that would need to occur to induce each additional adverse event was 111 for death, 20 for MACE, 125 for MI, and 29 for urgent CABG.
Also reassuring, the authors say, is the decline in event rates over time. The trend “underlines the importance of an ongoing need for further development of techniques and equipment to improve procedural success rates for CTO PCI,” they write. “A positive influence of operator expertise and experience on procedural success and short-term outcomes in patients with CTO PCI is well documented, which further stresses the importance of special dedicated CTO training, experienced CTO operators, and the development of high-volume CTO centers. We also suggest performing percutaneous CTO interventions preferably in the centers with cardiothoracic surgery back-up due to relatively higher rates of urgent CABG… in the failed group.”
In a telephone interview with TCTMD, Dimitrios Karmpaliotis, MD, PhD, of Columbia University Medical Center (New York, NY), stressed that CTO PCI is a “different animal” from PCI in general and is associated with complications not easily managed by all interventional cardiologists.
“It has its own nomenclature, its own techniques, and it requires skills and familiarity with equipment that is not widely known and mastered by all interventionalists,” he said. “It should be approached in a systematic and programmatic way; it should not be taken lightly.”
The main significance of this study, Dr. Karmpaliotis added, is that it shows outcomes from CTO PCI have improved over the years, driven by “operator experience, improved technology and equipment, potentially better patient selection, and collaboration and dedication among CTO experts from all over the world.”
Khan MF, Brilakis ES, Wendel CS, Thai H. Comparison of procedural complications and in-hospital clinical outcomes between patients with successful and failed percutaneous intervention of coronary chronic total occlusions: a meta-analysis of observational studies. Catheter Cardiovasc Interv. 2014;Epub ahead of print.
- Dr. Khan reports no relevant conflicts of interest.
- Dr. Karmpaliotis reports serving on the speaker’s bureau for Abbott, Asahi, Boston Scientific, and Medtronic.