Experienced, high volume operators performed better than inexperienced ones when performing unprotected left main coronary artery PCI procedures, according to a study in China.

The researchers found that unadjusted and adjusted risks for 30-day and three-year cardiac death were significantly lower for patients treated by experienced operators. They defined an experienced operator as one who performed at least 15 left main coronary artery PCIs per year for at least three consecutive years.

Lead researcher Bo Xu, MBBS, of Fu Wai Hospital and the Chinese Academy of Medical Sciences in Beijing, China, and colleagues published their results online Oct. 17 in the Journal of the American College of Cardiology: Cardiovascular Interventions.

“Our findings suggest that high-risk and complex procedures, such as left main PCI, should be reserved to a limited number of experienced operators in order to achieve the best outcomes,” Yuejin Yang, MD, one of the study’s authors, said in a news release. “Alternatively, less experienced operators could perform left main PCI under the close supervision and mentorship of an experienced operator until they acquire sufficient skill and technique to become independent.”

Previous research showed that left main coronary artery PCI was associated with favorable outcomes compared with coronary artery bypass grafting (CABG) in patients with low or intermediate SYNTAX scores and/or a lesion anatomy deemed suitable for PCI, according to the researchers.

For this study, they examined 25 operators who performed unprotected left main coronary artery PCI on 1,948 patients from January 2004 to December 2011 at Fu Wai Hospital in Beijing. There were seven high-volume operators and 18 low-volume operators. The high-volume operators performed procedures on 73 percent of the patients.

The mean number of left main coronary artery PCI performed each year was 12 in the overall group, including 25 among high-volume operators and four among low-volume operators.

Patients who underwent the procedures with high-volume operators had more extensive coronary artery disease and were more likely to have complex lesions, receive first-generation drug-eluting stents and have higher SYNTAX and SYNTAX II scores.

The 30-day mortality rates were 0.6 percent for patients treated by high-volume operators and 2.1 percent for patients treated by low-volume operators, which was a statistically significant difference. The three-year mortality rates were 3.8 percent and 5.3 percent, respectively, which was not significantly different.

The 30-day rates of MI, stroke, target vessel revascularization (TVR) and stent thrombosis were lower in patients treated by high-volume operators, but the differences were not significantly different. At three years, there were no significant differences in rates of MI, stent thrombosis or TVR.

After adjusting for cardiovascular risk factors and performing a multivariate Cox proportional hazards regression, the researchers found that treatment by a high-volume operator was associated with a 49 percent reduced risk for cardiac death.

Subgroup analyses found that operator experience had no significant affect on the risk of cardiac death at three years when assessing whether they used one or two stents, whether the target lesion involved the distal left main bifurcation and whether they used intravascular ultrasound.

The researchers acknowledged a few potential limitations of the study, including its retrospective design and the fact it only included one hospital. They also mentioned that the event rates were low and that the primary endpoint of cardiac death did not occur often.

“The operator’s experience and annual volume should be integrated with traditional risk stratification algorithms (SYNTAX score, SYNTAX score II) when debating revascularization strategies (PCI vs. CABG) for a given patient within a given institution,” the researchers wrote. “The impact of operator experience on prognosis after other types of high-risk PCI and CABG should be further studied.”