Less than 5 percent of patients with unprotected left main coronary artery (ULMCA) stenosis received ULMCA PCI. Researchers found that the PCI is usually carried out in higher risk patients, and the elderly tend to see more adverse events, according to reports from the 2004-2008 National Cardiovascular Data Registry (NCDR) published in the Feb. 14 issue of the Journal of the American College of Cardiology.
Linking data from both NCDR and CathPCI registries, J. Matthews Brennan, MD, MPH, of the Duke University Medical Center in Durham, N.C., and colleagues evaluated data of 5,627 patients who underwent ULMCA PCI at 693 centers to examine trends of PCI. During the study, Brennan et al reported 30-day mortality rates as well as rates of major adverse events with drug-eluting stents (DES) vs. bare-metal stents (BMS).
When discussing ULMCA PCI trends, the researchers said that this type of PCI was “rare” at most centers. In fact, 660 of the centers included in the study had procedural volume that dipped below 30 total procedures over the five-year span.
The researchers classified volume as low when centers performed less than six procedures per year, moderate when centers performed six to 15 procedures per year and high when centers performed more than 15 procedures per year. Twenty-five centers had between 30 and 75 total procedures and eight centers performed more than 75 ULMCA procedures over the five-year study period.
Of the procedures, 81.8 percent were performed with DES in low-urgency procedures. Death rates were lower among those treated with DES vs. BMS, 39.6 percent vs. 52.7 percent. Brennan et al also reported that 95 percent of patients survived to hospital discharge, but stented patients had a higher unadjusted in-hospital mortality rate compared with non-stented patients, 13.1 percent vs. 4.6 percent.
Patients with high clinical urgency were associated with higher unadjusted in-hospital mortality compared with low clinical urgency, 45.1 percent vs. 2.9 percent, respectively.
Of the 2,765 patients included in follow-up assessments, 57.9 percent experienced a major adverse event by 30 months. After 30 months, unadjusted incidence of death was reported to be 35.4 percent vs. 36.4 percent vs. 33.9 percent in low-, moderate-, and high-volume centers, respectively.
However, the authors noted that event rates for high-urgency patients most commonly occurred in centers with the highest ULMCA PCI volume. These numbers were 72.7 percent in low-volume centers, 76.9 percent in moderate-volume centers and 80 percent in high-volume centers. The numbers for lower urgency patients were reported to be 50.1 percent, 52.5 percent and 60.3 percent, respectively.
The researchers said that 40 percent of elderly patients who received ULMCA PCI were at risk of dying within the first three years of follow-up. Additionally, the authors reported that rates of ULMCA PCI were low in the U.S but are slowly increasing.
The researchers suggested that a randomized clinical trial should be conducted to study the safety and effectiveness of ULMCA PCI.
“ULMCA PCI remains a relatively uncommon procedure at most U.S. centers and is primarily reserved for those at high risk for coronary artery bypass graft surgery,” the authors summed. “Poor outcomes following percutaneous revascularization in elderly ULMCA patients are common and are likely influenced by both patient and procedural characteristics.”