Left main percutaneous coronary intervention (PCI) with high-volume and more experienced operators was associated with better short- and long-term outcomes, according to a retrospective study published in JACC: Cardiovascular Interventions.
The researchers included 1949 consecutive patients who underwent unprotected left main PCI from January 2004 to December 2011 in Beijing, China. An experienced and high-volume PCI operator was defined as an operator who performed at least 15 left main PCIs per year for at least 3 consecutive years.
The designated primary end point was cardiac mortality at 3 years after PCI. The main secondary end point was cardiac death at 30 days. Additional secondary end points included rates of all-cause death, myocardial infarction (MI), stent thrombosis, stroke, and target vessel revascularization (TVR) at 30 days and 3 years.
Of the total cohort, 1422 (73%) were treated by 7 high-volume operators (28%) and 526 were treated by 18 low-volume operators (72%). The mean number of left main PCIs performed each year per operator was 12 ± 12 (high-volume operators: 25 ± 8 and low-volume operators: 4 ± 3).
More extensive coronary artery disease (CAD) and more complex lesions were present in patients who underwent left main PCI by high-volume operators. These patients were also more likely to receive first-generation rather than second-generation drug-eluting stents. In addition, high-volume operators more frequently used intravascular ultrasound (IVUS) to guide their procedures (39.2% vs 31.7%; P =.002).
At 30 days, patients treated by high-volume operators had a mortality rate of 0.6% while those treated by low-volume operators had a rate of 2.1% (P =.008). MI, stroke, TVR, and stent thrombosis were reduced by a nonstatistically significant amount.
On the other hand, there was a lower adjusted risk for cardiac death (adjusted hazard ratio [HR]: 0.22; 95% confidence interval [CI], 0.09-0.59; P= .003) and all-cause mortality (adjusted HR: 0.30; 95% CI, 0.12-0.73; P =.008) as well as a trend toward a decreased risk for stent thrombosis (adjusted HR: 0.34; 95% CI, 0.11-1.06; P =.06) at 30-days post-PCI.
At 3 years, follow-up data were available for 92% of patients. There was a statistically significant trend toward lower risk for cardiac death when patients were stratified into tertiles based on operator experience. This same trend occurred when operators were stratified into tertiles. Patients treated by high-volume operators had a significantly lower risk for the primary end point, cardiac death (2.5% vs 4.6%; P =.02), with a trend toward lower all-cause mortality (3.8% vs 5.3%; P =.15). Again, there were no significant differences observed in rates of MI, stent thrombosis, or TVR between experienced and non-experienced operators.
“We show that operator experience appears to be important regardless of LM [left main] PCI type (ie, proximal lesion vs distal LM bifurcation lesion and 1 stent vs 2 stents) and whether IVUS is used to guide the procedure,” the authors wrote. “Importantly, patients who were treated by experienced operators had a better prognosis despite the fact that this group had more advanced CAD, underwent more technically complex procedures, and were less likely to receive second-generation [drug-eluting stents].”
The researchers recommended combining the operator’s experience and annual volume with traditional risk stratification algorithms (eg, SYNTAX score and SYNTAX score II) when considering revascularization methods.
- This study should be considered hypothesis-generating because of its retrospective nature.
- Low event rates, particularly at 30 days, may have resulted in overfitting of the multivariate Cox models.
- The primary end point of cardiac death was a rare event in this cohort, which may have possibly introduced type II error from the resulting reduced statistical power.
- Being that this was a single-center study, its external validity is uncertain. These operators were highly experienced and whether or not these results can extend to differences in experience in much less experienced operators remains to be seen.
Disclosures: The authors reported that they have no relevant financial relationships to disclose.
Xu B, Redfords B, Yang Y, et al. Impact of operator experience and volume on outcomes after left main coronary artery percutaneous coronary intervention. JACC Cardiovasc Interv. 2016;9(20):2086-2093. doi:10.1016/j.jcin.2016.08.011.